1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
68 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
69 This is used by the `remember_end_note' function to record the endpoint
70 of each generated block in its associated BLOCK node. */
72 static rtx last_block_end_note;
74 /* Functions and data structures for expanding case statements. */
76 /* Case label structure, used to hold info on labels within case
77 statements. We handle "range" labels; for a single-value label
78 as in C, the high and low limits are the same.
80 An AVL tree of case nodes is initially created, and later transformed
81 to a list linked via the RIGHT fields in the nodes. Nodes with
82 higher case values are later in the list.
84 Switch statements can be output in one of two forms. A branch table
85 is used if there are more than a few labels and the labels are dense
86 within the range between the smallest and largest case value. If a
87 branch table is used, no further manipulations are done with the case
90 The alternative to the use of a branch table is to generate a series
91 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
92 and PARENT fields to hold a binary tree. Initially the tree is
93 totally unbalanced, with everything on the right. We balance the tree
94 with nodes on the left having lower case values than the parent
95 and nodes on the right having higher values. We then output the tree
100 struct case_node *left; /* Left son in binary tree */
101 struct case_node *right; /* Right son in binary tree; also node chain */
102 struct case_node *parent; /* Parent of node in binary tree */
103 tree low; /* Lowest index value for this label */
104 tree high; /* Highest index value for this label */
105 tree code_label; /* Label to jump to when node matches */
109 typedef struct case_node case_node;
110 typedef struct case_node *case_node_ptr;
112 /* These are used by estimate_case_costs and balance_case_nodes. */
114 /* This must be a signed type, and non-ANSI compilers lack signed char. */
115 static short *cost_table;
116 static int use_cost_table;
118 /* Stack of control and binding constructs we are currently inside.
120 These constructs begin when you call `expand_start_WHATEVER'
121 and end when you call `expand_end_WHATEVER'. This stack records
122 info about how the construct began that tells the end-function
123 what to do. It also may provide information about the construct
124 to alter the behavior of other constructs within the body.
125 For example, they may affect the behavior of C `break' and `continue'.
127 Each construct gets one `struct nesting' object.
128 All of these objects are chained through the `all' field.
129 `nesting_stack' points to the first object (innermost construct).
130 The position of an entry on `nesting_stack' is in its `depth' field.
132 Each type of construct has its own individual stack.
133 For example, loops have `loop_stack'. Each object points to the
134 next object of the same type through the `next' field.
136 Some constructs are visible to `break' exit-statements and others
137 are not. Which constructs are visible depends on the language.
138 Therefore, the data structure allows each construct to be visible
139 or not, according to the args given when the construct is started.
140 The construct is visible if the `exit_label' field is non-null.
141 In that case, the value should be a CODE_LABEL rtx. */
146 struct nesting *next;
151 /* For conds (if-then and if-then-else statements). */
154 /* Label for the end of the if construct.
155 There is none if EXITFLAG was not set
156 and no `else' has been seen yet. */
158 /* Label for the end of this alternative.
159 This may be the end of the if or the next else/elseif. */
165 /* Label at the top of the loop; place to loop back to. */
167 /* Label at the end of the whole construct. */
169 /* Label before a jump that branches to the end of the whole
170 construct. This is where destructors go if any. */
172 /* Label for `continue' statement to jump to;
173 this is in front of the stepper of the loop. */
176 /* For variable binding contours. */
179 /* Sequence number of this binding contour within the function,
180 in order of entry. */
181 int block_start_count;
182 /* Nonzero => value to restore stack to on exit. */
184 /* The NOTE that starts this contour.
185 Used by expand_goto to check whether the destination
186 is within each contour or not. */
188 /* Innermost containing binding contour that has a stack level. */
189 struct nesting *innermost_stack_block;
190 /* List of cleanups to be run on exit from this contour.
191 This is a list of expressions to be evaluated.
192 The TREE_PURPOSE of each link is the ..._DECL node
193 which the cleanup pertains to. */
195 /* List of cleanup-lists of blocks containing this block,
196 as they were at the locus where this block appears.
197 There is an element for each containing block,
198 ordered innermost containing block first.
199 The tail of this list can be 0,
200 if all remaining elements would be empty lists.
201 The element's TREE_VALUE is the cleanup-list of that block,
202 which may be null. */
204 /* Chain of labels defined inside this binding contour.
205 For contours that have stack levels or cleanups. */
206 struct label_chain *label_chain;
207 /* Number of function calls seen, as of start of this block. */
208 int n_function_calls;
209 /* Nonzero if this is associated with a EH region. */
210 int exception_region;
211 /* The saved target_temp_slot_level from our outer block.
212 We may reset target_temp_slot_level to be the level of
213 this block, if that is done, target_temp_slot_level
214 reverts to the saved target_temp_slot_level at the very
216 int block_target_temp_slot_level;
217 /* True if we are currently emitting insns in an area of
218 output code that is controlled by a conditional
219 expression. This is used by the cleanup handling code to
220 generate conditional cleanup actions. */
221 int conditional_code;
222 /* A place to move the start of the exception region for any
223 of the conditional cleanups, must be at the end or after
224 the start of the last unconditional cleanup, and before any
225 conditional branch points. */
226 rtx last_unconditional_cleanup;
227 /* When in a conditional context, this is the specific
228 cleanup list associated with last_unconditional_cleanup,
229 where we place the conditionalized cleanups. */
232 /* For switch (C) or case (Pascal) statements,
233 and also for dummies (see `expand_start_case_dummy'). */
236 /* The insn after which the case dispatch should finally
237 be emitted. Zero for a dummy. */
239 /* A list of case labels; it is first built as an AVL tree.
240 During expand_end_case, this is converted to a list, and may be
241 rearranged into a nearly balanced binary tree. */
242 struct case_node *case_list;
243 /* Label to jump to if no case matches. */
245 /* The expression to be dispatched on. */
247 /* Type that INDEX_EXPR should be converted to. */
249 /* Number of range exprs in case statement. */
251 /* Name of this kind of statement, for warnings. */
252 const char *printname;
253 /* Used to save no_line_numbers till we see the first case label.
254 We set this to -1 when we see the first case label in this
256 int line_number_status;
261 /* Allocate and return a new `struct nesting'. */
263 #define ALLOC_NESTING() \
264 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
266 /* Pop the nesting stack element by element until we pop off
267 the element which is at the top of STACK.
268 Update all the other stacks, popping off elements from them
269 as we pop them from nesting_stack. */
271 #define POPSTACK(STACK) \
272 do { struct nesting *target = STACK; \
273 struct nesting *this; \
274 do { this = nesting_stack; \
275 if (loop_stack == this) \
276 loop_stack = loop_stack->next; \
277 if (cond_stack == this) \
278 cond_stack = cond_stack->next; \
279 if (block_stack == this) \
280 block_stack = block_stack->next; \
281 if (stack_block_stack == this) \
282 stack_block_stack = stack_block_stack->next; \
283 if (case_stack == this) \
284 case_stack = case_stack->next; \
285 nesting_depth = nesting_stack->depth - 1; \
286 nesting_stack = this->all; \
287 obstack_free (&stmt_obstack, this); } \
288 while (this != target); } while (0)
290 /* In some cases it is impossible to generate code for a forward goto
291 until the label definition is seen. This happens when it may be necessary
292 for the goto to reset the stack pointer: we don't yet know how to do that.
293 So expand_goto puts an entry on this fixup list.
294 Each time a binding contour that resets the stack is exited,
296 If the target label has now been defined, we can insert the proper code. */
300 /* Points to following fixup. */
301 struct goto_fixup *next;
302 /* Points to the insn before the jump insn.
303 If more code must be inserted, it goes after this insn. */
305 /* The LABEL_DECL that this jump is jumping to, or 0
306 for break, continue or return. */
308 /* The BLOCK for the place where this goto was found. */
310 /* The CODE_LABEL rtx that this is jumping to. */
312 /* Number of binding contours started in current function
313 before the label reference. */
314 int block_start_count;
315 /* The outermost stack level that should be restored for this jump.
316 Each time a binding contour that resets the stack is exited,
317 if the target label is *not* yet defined, this slot is updated. */
319 /* List of lists of cleanup expressions to be run by this goto.
320 There is one element for each block that this goto is within.
321 The tail of this list can be 0,
322 if all remaining elements would be empty.
323 The TREE_VALUE contains the cleanup list of that block as of the
324 time this goto was seen.
325 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
326 tree cleanup_list_list;
329 /* Within any binding contour that must restore a stack level,
330 all labels are recorded with a chain of these structures. */
334 /* Points to following fixup. */
335 struct label_chain *next;
341 /* Chain of all pending binding contours. */
342 struct nesting *x_block_stack;
344 /* If any new stacks are added here, add them to POPSTACKS too. */
346 /* Chain of all pending binding contours that restore stack levels
348 struct nesting *x_stack_block_stack;
350 /* Chain of all pending conditional statements. */
351 struct nesting *x_cond_stack;
353 /* Chain of all pending loops. */
354 struct nesting *x_loop_stack;
356 /* Chain of all pending case or switch statements. */
357 struct nesting *x_case_stack;
359 /* Separate chain including all of the above,
360 chained through the `all' field. */
361 struct nesting *x_nesting_stack;
363 /* Number of entries on nesting_stack now. */
366 /* Number of binding contours started so far in this function. */
367 int x_block_start_count;
369 /* Each time we expand an expression-statement,
370 record the expr's type and its RTL value here. */
371 tree x_last_expr_type;
372 rtx x_last_expr_value;
374 /* Nonzero if within a ({...}) grouping, in which case we must
375 always compute a value for each expr-stmt in case it is the last one. */
376 int x_expr_stmts_for_value;
378 /* Filename and line number of last line-number note,
379 whether we actually emitted it or not. */
380 char *x_emit_filename;
383 struct goto_fixup *x_goto_fixup_chain;
386 #define block_stack (current_function->stmt->x_block_stack)
387 #define stack_block_stack (current_function->stmt->x_stack_block_stack)
388 #define cond_stack (current_function->stmt->x_cond_stack)
389 #define loop_stack (current_function->stmt->x_loop_stack)
390 #define case_stack (current_function->stmt->x_case_stack)
391 #define nesting_stack (current_function->stmt->x_nesting_stack)
392 #define nesting_depth (current_function->stmt->x_nesting_depth)
393 #define current_block_start_count (current_function->stmt->x_block_start_count)
394 #define last_expr_type (current_function->stmt->x_last_expr_type)
395 #define last_expr_value (current_function->stmt->x_last_expr_value)
396 #define expr_stmts_for_value (current_function->stmt->x_expr_stmts_for_value)
397 #define emit_filename (current_function->stmt->x_emit_filename)
398 #define emit_lineno (current_function->stmt->x_emit_lineno)
399 #define goto_fixup_chain (current_function->stmt->x_goto_fixup_chain)
401 /* Non-zero if we are using EH to handle cleanus. */
402 static int using_eh_for_cleanups_p = 0;
405 static int n_occurrences PROTO((int, const char *));
406 static void expand_goto_internal PROTO((tree, rtx, rtx));
407 static int expand_fixup PROTO((tree, rtx, rtx));
408 static rtx expand_nl_handler_label PROTO((rtx, rtx));
409 static void expand_nl_goto_receiver PROTO((void));
410 static void expand_nl_goto_receivers PROTO((struct nesting *));
411 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
413 static void expand_null_return_1 PROTO((rtx, int));
414 static void expand_value_return PROTO((rtx));
415 static int tail_recursion_args PROTO((tree, tree));
416 static void expand_cleanups PROTO((tree, tree, int, int));
417 static void check_seenlabel PROTO((void));
418 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
419 static int estimate_case_costs PROTO((case_node_ptr));
420 static void group_case_nodes PROTO((case_node_ptr));
421 static void balance_case_nodes PROTO((case_node_ptr *,
423 static int node_has_low_bound PROTO((case_node_ptr, tree));
424 static int node_has_high_bound PROTO((case_node_ptr, tree));
425 static int node_is_bounded PROTO((case_node_ptr, tree));
426 static void emit_jump_if_reachable PROTO((rtx));
427 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
428 static int add_case_node PROTO((tree, tree, tree, tree *));
429 static struct case_node *case_tree2list PROTO((case_node *, case_node *));
430 static void mark_cond_nesting PROTO((struct nesting *));
431 static void mark_loop_nesting PROTO((struct nesting *));
432 static void mark_block_nesting PROTO((struct nesting *));
433 static void mark_case_nesting PROTO((struct nesting *));
434 static void mark_goto_fixup PROTO((struct goto_fixup *));
438 using_eh_for_cleanups ()
440 using_eh_for_cleanups_p = 1;
443 /* Mark N (known to be a cond-nesting) for GC. */
446 mark_cond_nesting (n)
451 ggc_mark_rtx (n->exit_label);
452 ggc_mark_rtx (n->data.cond.endif_label);
453 ggc_mark_rtx (n->data.cond.next_label);
459 /* Mark N (known to be a loop-nesting) for GC. */
462 mark_loop_nesting (n)
468 ggc_mark_rtx (n->exit_label);
469 ggc_mark_rtx (n->data.loop.start_label);
470 ggc_mark_rtx (n->data.loop.end_label);
471 ggc_mark_rtx (n->data.loop.alt_end_label);
472 ggc_mark_rtx (n->data.loop.continue_label);
478 /* Mark N (known to be a block-nesting) for GC. */
481 mark_block_nesting (n)
486 struct label_chain *l;
488 ggc_mark_rtx (n->exit_label);
489 ggc_mark_rtx (n->data.block.stack_level);
490 ggc_mark_rtx (n->data.block.first_insn);
491 ggc_mark_tree (n->data.block.cleanups);
492 ggc_mark_tree (n->data.block.outer_cleanups);
494 for (l = n->data.block.label_chain; l != NULL; l = l->next)
495 ggc_mark_tree (l->label);
497 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
499 /* ??? cleanup_ptr never points outside the stack, does it? */
505 /* Mark N (known to be a case-nesting) for GC. */
508 mark_case_nesting (n)
513 struct case_node *node;
515 ggc_mark_rtx (n->exit_label);
516 ggc_mark_rtx (n->data.case_stmt.start);
518 node = n->data.case_stmt.case_list;
521 ggc_mark_tree (node->low);
522 ggc_mark_tree (node->high);
523 ggc_mark_tree (node->code_label);
527 ggc_mark_tree (n->data.case_stmt.default_label);
528 ggc_mark_tree (n->data.case_stmt.index_expr);
529 ggc_mark_tree (n->data.case_stmt.nominal_type);
539 struct goto_fixup *g;
543 ggc_mark_rtx (g->before_jump);
544 ggc_mark_tree (g->target);
545 ggc_mark_tree (g->context);
546 ggc_mark_rtx (g->target_rtl);
547 ggc_mark_rtx (g->stack_level);
548 ggc_mark_tree (g->cleanup_list_list);
554 /* Clear out all parts of the state in F that can safely be discarded
555 after the function has been compiled, to let garbage collection
556 reclaim the memory. */
562 /* We're about to free the function obstack. If we hold pointers to
563 things allocated there, then we'll try to mark them when we do
564 GC. So, we clear them out here explicitly. */
574 struct stmt_status *p;
579 mark_block_nesting (p->x_block_stack);
580 mark_cond_nesting (p->x_cond_stack);
581 mark_loop_nesting (p->x_loop_stack);
582 mark_case_nesting (p->x_case_stack);
584 ggc_mark_tree (p->x_last_expr_type);
585 /* last_epxr_value is only valid if last_expr_type is nonzero. */
586 if (p->x_last_expr_type)
587 ggc_mark_rtx (p->x_last_expr_value);
589 mark_goto_fixup (p->x_goto_fixup_chain);
595 gcc_obstack_init (&stmt_obstack);
599 init_stmt_for_function ()
601 current_function->stmt
602 = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
604 /* We are not currently within any block, conditional, loop or case. */
606 stack_block_stack = 0;
613 current_block_start_count = 0;
615 /* No gotos have been expanded yet. */
616 goto_fixup_chain = 0;
618 /* We are not processing a ({...}) grouping. */
619 expr_stmts_for_value = 0;
621 last_expr_value = NULL_RTX;
624 /* Return nonzero if anything is pushed on the loop, condition, or case
629 return cond_stack || loop_stack || case_stack;
632 /* Record the current file and line. Called from emit_line_note. */
634 set_file_and_line_for_stmt (file, line)
638 emit_filename = file;
642 /* Emit a no-op instruction. */
649 last_insn = get_last_insn ();
651 && (GET_CODE (last_insn) == CODE_LABEL
652 || (GET_CODE (last_insn) == NOTE
653 && prev_real_insn (last_insn) == 0)))
654 emit_insn (gen_nop ());
657 /* Return the rtx-label that corresponds to a LABEL_DECL,
658 creating it if necessary. */
664 if (TREE_CODE (label) != LABEL_DECL)
667 if (DECL_RTL (label))
668 return DECL_RTL (label);
670 return DECL_RTL (label) = gen_label_rtx ();
673 /* Add an unconditional jump to LABEL as the next sequential instruction. */
679 do_pending_stack_adjust ();
680 emit_jump_insn (gen_jump (label));
684 /* Emit code to jump to the address
685 specified by the pointer expression EXP. */
688 expand_computed_goto (exp)
691 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
693 #ifdef POINTERS_EXTEND_UNSIGNED
694 x = convert_memory_address (Pmode, x);
698 /* Be sure the function is executable. */
699 if (current_function_check_memory_usage)
700 emit_library_call (chkr_check_exec_libfunc, 1,
701 VOIDmode, 1, x, ptr_mode);
703 do_pending_stack_adjust ();
704 emit_indirect_jump (x);
706 current_function_has_computed_jump = 1;
709 /* Handle goto statements and the labels that they can go to. */
711 /* Specify the location in the RTL code of a label LABEL,
712 which is a LABEL_DECL tree node.
714 This is used for the kind of label that the user can jump to with a
715 goto statement, and for alternatives of a switch or case statement.
716 RTL labels generated for loops and conditionals don't go through here;
717 they are generated directly at the RTL level, by other functions below.
719 Note that this has nothing to do with defining label *names*.
720 Languages vary in how they do that and what that even means. */
726 struct label_chain *p;
728 do_pending_stack_adjust ();
729 emit_label (label_rtx (label));
730 if (DECL_NAME (label))
731 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
733 if (stack_block_stack != 0)
735 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
736 p->next = stack_block_stack->data.block.label_chain;
737 stack_block_stack->data.block.label_chain = p;
742 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
743 from nested functions. */
746 declare_nonlocal_label (label)
749 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
751 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
752 LABEL_PRESERVE_P (label_rtx (label)) = 1;
753 if (nonlocal_goto_handler_slots == 0)
755 emit_stack_save (SAVE_NONLOCAL,
756 &nonlocal_goto_stack_level,
757 PREV_INSN (tail_recursion_reentry));
759 nonlocal_goto_handler_slots
760 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
763 /* Generate RTL code for a `goto' statement with target label LABEL.
764 LABEL should be a LABEL_DECL tree node that was or will later be
765 defined with `expand_label'. */
773 /* Check for a nonlocal goto to a containing function. */
774 context = decl_function_context (label);
775 if (context != 0 && context != current_function_decl)
777 struct function *p = find_function_data (context);
778 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
779 rtx temp, handler_slot;
782 /* Find the corresponding handler slot for this label. */
783 handler_slot = p->x_nonlocal_goto_handler_slots;
784 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
785 link = TREE_CHAIN (link))
786 handler_slot = XEXP (handler_slot, 1);
787 handler_slot = XEXP (handler_slot, 0);
789 p->has_nonlocal_label = 1;
790 current_function_has_nonlocal_goto = 1;
791 LABEL_REF_NONLOCAL_P (label_ref) = 1;
793 /* Copy the rtl for the slots so that they won't be shared in
794 case the virtual stack vars register gets instantiated differently
795 in the parent than in the child. */
797 #if HAVE_nonlocal_goto
798 if (HAVE_nonlocal_goto)
799 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
800 copy_rtx (handler_slot),
801 copy_rtx (p->x_nonlocal_goto_stack_level),
808 /* Restore frame pointer for containing function.
809 This sets the actual hard register used for the frame pointer
810 to the location of the function's incoming static chain info.
811 The non-local goto handler will then adjust it to contain the
812 proper value and reload the argument pointer, if needed. */
813 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
815 /* We have now loaded the frame pointer hardware register with
816 the address of that corresponds to the start of the virtual
817 stack vars. So replace virtual_stack_vars_rtx in all
818 addresses we use with stack_pointer_rtx. */
820 /* Get addr of containing function's current nonlocal goto handler,
821 which will do any cleanups and then jump to the label. */
822 addr = copy_rtx (handler_slot);
823 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
824 hard_frame_pointer_rtx));
826 /* Restore the stack pointer. Note this uses fp just restored. */
827 addr = p->x_nonlocal_goto_stack_level;
829 addr = replace_rtx (copy_rtx (addr),
830 virtual_stack_vars_rtx,
831 hard_frame_pointer_rtx);
833 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
835 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
837 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
838 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
839 emit_indirect_jump (temp);
843 expand_goto_internal (label, label_rtx (label), NULL_RTX);
846 /* Generate RTL code for a `goto' statement with target label BODY.
847 LABEL should be a LABEL_REF.
848 LAST_INSN, if non-0, is the rtx we should consider as the last
849 insn emitted (for the purposes of cleaning up a return). */
852 expand_goto_internal (body, label, last_insn)
857 struct nesting *block;
860 if (GET_CODE (label) != CODE_LABEL)
863 /* If label has already been defined, we can tell now
864 whether and how we must alter the stack level. */
866 if (PREV_INSN (label) != 0)
868 /* Find the innermost pending block that contains the label.
869 (Check containment by comparing insn-uids.)
870 Then restore the outermost stack level within that block,
871 and do cleanups of all blocks contained in it. */
872 for (block = block_stack; block; block = block->next)
874 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
876 if (block->data.block.stack_level != 0)
877 stack_level = block->data.block.stack_level;
878 /* Execute the cleanups for blocks we are exiting. */
879 if (block->data.block.cleanups != 0)
881 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
882 do_pending_stack_adjust ();
888 /* Ensure stack adjust isn't done by emit_jump, as this
889 would clobber the stack pointer. This one should be
890 deleted as dead by flow. */
891 clear_pending_stack_adjust ();
892 do_pending_stack_adjust ();
893 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
896 if (body != 0 && DECL_TOO_LATE (body))
897 error ("jump to `%s' invalidly jumps into binding contour",
898 IDENTIFIER_POINTER (DECL_NAME (body)));
900 /* Label not yet defined: may need to put this goto
901 on the fixup list. */
902 else if (! expand_fixup (body, label, last_insn))
904 /* No fixup needed. Record that the label is the target
905 of at least one goto that has no fixup. */
907 TREE_ADDRESSABLE (body) = 1;
913 /* Generate if necessary a fixup for a goto
914 whose target label in tree structure (if any) is TREE_LABEL
915 and whose target in rtl is RTL_LABEL.
917 If LAST_INSN is nonzero, we pretend that the jump appears
918 after insn LAST_INSN instead of at the current point in the insn stream.
920 The fixup will be used later to insert insns just before the goto.
921 Those insns will restore the stack level as appropriate for the
922 target label, and will (in the case of C++) also invoke any object
923 destructors which have to be invoked when we exit the scopes which
924 are exited by the goto.
926 Value is nonzero if a fixup is made. */
929 expand_fixup (tree_label, rtl_label, last_insn)
934 struct nesting *block, *end_block;
936 /* See if we can recognize which block the label will be output in.
937 This is possible in some very common cases.
938 If we succeed, set END_BLOCK to that block.
939 Otherwise, set it to 0. */
942 && (rtl_label == cond_stack->data.cond.endif_label
943 || rtl_label == cond_stack->data.cond.next_label))
944 end_block = cond_stack;
945 /* If we are in a loop, recognize certain labels which
946 are likely targets. This reduces the number of fixups
947 we need to create. */
949 && (rtl_label == loop_stack->data.loop.start_label
950 || rtl_label == loop_stack->data.loop.end_label
951 || rtl_label == loop_stack->data.loop.continue_label))
952 end_block = loop_stack;
956 /* Now set END_BLOCK to the binding level to which we will return. */
960 struct nesting *next_block = end_block->all;
963 /* First see if the END_BLOCK is inside the innermost binding level.
964 If so, then no cleanups or stack levels are relevant. */
965 while (next_block && next_block != block)
966 next_block = next_block->all;
971 /* Otherwise, set END_BLOCK to the innermost binding level
972 which is outside the relevant control-structure nesting. */
973 next_block = block_stack->next;
974 for (block = block_stack; block != end_block; block = block->all)
975 if (block == next_block)
976 next_block = next_block->next;
977 end_block = next_block;
980 /* Does any containing block have a stack level or cleanups?
981 If not, no fixup is needed, and that is the normal case
982 (the only case, for standard C). */
983 for (block = block_stack; block != end_block; block = block->next)
984 if (block->data.block.stack_level != 0
985 || block->data.block.cleanups != 0)
988 if (block != end_block)
990 /* Ok, a fixup is needed. Add a fixup to the list of such. */
991 struct goto_fixup *fixup
992 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
993 /* In case an old stack level is restored, make sure that comes
994 after any pending stack adjust. */
995 /* ?? If the fixup isn't to come at the present position,
996 doing the stack adjust here isn't useful. Doing it with our
997 settings at that location isn't useful either. Let's hope
1000 do_pending_stack_adjust ();
1001 fixup->target = tree_label;
1002 fixup->target_rtl = rtl_label;
1004 /* Create a BLOCK node and a corresponding matched set of
1005 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1006 this point. The notes will encapsulate any and all fixup
1007 code which we might later insert at this point in the insn
1008 stream. Also, the BLOCK node will be the parent (i.e. the
1009 `SUPERBLOCK') of any other BLOCK nodes which we might create
1010 later on when we are expanding the fixup code.
1012 Note that optimization passes (including expand_end_loop)
1013 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1014 as a placeholder. */
1017 register rtx original_before_jump
1018 = last_insn ? last_insn : get_last_insn ();
1022 block = make_node (BLOCK);
1023 TREE_USED (block) = 1;
1025 if (current_function->x_whole_function_mode_p)
1027 find_loop_tree_blocks ();
1028 retrofit_block (block, original_before_jump);
1031 insert_block (block);
1034 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1035 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1036 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1037 fixup->context = block;
1039 emit_insns_after (start, original_before_jump);
1042 fixup->block_start_count = current_block_start_count;
1043 fixup->stack_level = 0;
1044 fixup->cleanup_list_list
1045 = ((block->data.block.outer_cleanups
1046 || block->data.block.cleanups)
1047 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1048 block->data.block.outer_cleanups)
1050 fixup->next = goto_fixup_chain;
1051 goto_fixup_chain = fixup;
1059 /* Expand any needed fixups in the outputmost binding level of the
1060 function. FIRST_INSN is the first insn in the function. */
1063 expand_fixups (first_insn)
1066 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1069 /* When exiting a binding contour, process all pending gotos requiring fixups.
1070 THISBLOCK is the structure that describes the block being exited.
1071 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1072 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1073 FIRST_INSN is the insn that began this contour.
1075 Gotos that jump out of this contour must restore the
1076 stack level and do the cleanups before actually jumping.
1078 DONT_JUMP_IN nonzero means report error there is a jump into this
1079 contour from before the beginning of the contour.
1080 This is also done if STACK_LEVEL is nonzero. */
1083 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1084 struct nesting *thisblock;
1090 register struct goto_fixup *f, *prev;
1092 /* F is the fixup we are considering; PREV is the previous one. */
1093 /* We run this loop in two passes so that cleanups of exited blocks
1094 are run first, and blocks that are exited are marked so
1097 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1099 /* Test for a fixup that is inactive because it is already handled. */
1100 if (f->before_jump == 0)
1102 /* Delete inactive fixup from the chain, if that is easy to do. */
1104 prev->next = f->next;
1106 /* Has this fixup's target label been defined?
1107 If so, we can finalize it. */
1108 else if (PREV_INSN (f->target_rtl) != 0)
1110 register rtx cleanup_insns;
1112 /* Get the first non-label after the label
1113 this goto jumps to. If that's before this scope begins,
1114 we don't have a jump into the scope. */
1115 rtx after_label = f->target_rtl;
1116 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1117 after_label = NEXT_INSN (after_label);
1119 /* If this fixup jumped into this contour from before the beginning
1120 of this contour, report an error. */
1121 /* ??? Bug: this does not detect jumping in through intermediate
1122 blocks that have stack levels or cleanups.
1123 It detects only a problem with the innermost block
1124 around the label. */
1126 && (dont_jump_in || stack_level || cleanup_list)
1127 /* If AFTER_LABEL is 0, it means the jump goes to the end
1128 of the rtl, which means it jumps into this scope. */
1129 && (after_label == 0
1130 || INSN_UID (first_insn) < INSN_UID (after_label))
1131 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1132 && ! DECL_ERROR_ISSUED (f->target))
1134 error_with_decl (f->target,
1135 "label `%s' used before containing binding contour");
1136 /* Prevent multiple errors for one label. */
1137 DECL_ERROR_ISSUED (f->target) = 1;
1140 /* We will expand the cleanups into a sequence of their own and
1141 then later on we will attach this new sequence to the insn
1142 stream just ahead of the actual jump insn. */
1146 /* Temporarily restore the lexical context where we will
1147 logically be inserting the fixup code. We do this for the
1148 sake of getting the debugging information right. */
1151 set_block (f->context);
1153 /* Expand the cleanups for blocks this jump exits. */
1154 if (f->cleanup_list_list)
1157 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1158 /* Marked elements correspond to blocks that have been closed.
1159 Do their cleanups. */
1160 if (TREE_ADDRESSABLE (lists)
1161 && TREE_VALUE (lists) != 0)
1163 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1164 /* Pop any pushes done in the cleanups,
1165 in case function is about to return. */
1166 do_pending_stack_adjust ();
1170 /* Restore stack level for the biggest contour that this
1171 jump jumps out of. */
1173 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1175 /* Finish up the sequence containing the insns which implement the
1176 necessary cleanups, and then attach that whole sequence to the
1177 insn stream just ahead of the actual jump insn. Attaching it
1178 at that point insures that any cleanups which are in fact
1179 implicit C++ object destructions (which must be executed upon
1180 leaving the block) appear (to the debugger) to be taking place
1181 in an area of the generated code where the object(s) being
1182 destructed are still "in scope". */
1184 cleanup_insns = get_insns ();
1188 emit_insns_after (cleanup_insns, f->before_jump);
1195 /* For any still-undefined labels, do the cleanups for this block now.
1196 We must do this now since items in the cleanup list may go out
1197 of scope when the block ends. */
1198 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1199 if (f->before_jump != 0
1200 && PREV_INSN (f->target_rtl) == 0
1201 /* Label has still not appeared. If we are exiting a block with
1202 a stack level to restore, that started before the fixup,
1203 mark this stack level as needing restoration
1204 when the fixup is later finalized. */
1206 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1207 means the label is undefined. That's erroneous, but possible. */
1208 && (thisblock->data.block.block_start_count
1209 <= f->block_start_count))
1211 tree lists = f->cleanup_list_list;
1214 for (; lists; lists = TREE_CHAIN (lists))
1215 /* If the following elt. corresponds to our containing block
1216 then the elt. must be for this block. */
1217 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1221 set_block (f->context);
1222 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1223 do_pending_stack_adjust ();
1224 cleanup_insns = get_insns ();
1227 if (cleanup_insns != 0)
1229 = emit_insns_after (cleanup_insns, f->before_jump);
1231 f->cleanup_list_list = TREE_CHAIN (lists);
1235 f->stack_level = stack_level;
1239 /* Return the number of times character C occurs in string S. */
1241 n_occurrences (c, s)
1251 /* Generate RTL for an asm statement (explicit assembler code).
1252 BODY is a STRING_CST node containing the assembler code text,
1253 or an ADDR_EXPR containing a STRING_CST. */
1259 if (current_function_check_memory_usage)
1261 error ("`asm' cannot be used in function where memory usage is checked");
1265 if (TREE_CODE (body) == ADDR_EXPR)
1266 body = TREE_OPERAND (body, 0);
1268 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1269 TREE_STRING_POINTER (body)));
1273 /* Generate RTL for an asm statement with arguments.
1274 STRING is the instruction template.
1275 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1276 Each output or input has an expression in the TREE_VALUE and
1277 a constraint-string in the TREE_PURPOSE.
1278 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1279 that is clobbered by this insn.
1281 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1282 Some elements of OUTPUTS may be replaced with trees representing temporary
1283 values. The caller should copy those temporary values to the originally
1286 VOL nonzero means the insn is volatile; don't optimize it. */
1289 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1290 tree string, outputs, inputs, clobbers;
1295 rtvec argvec, constraints;
1297 int ninputs = list_length (inputs);
1298 int noutputs = list_length (outputs);
1303 /* Vector of RTX's of evaluated output operands. */
1304 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1305 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1306 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1307 enum machine_mode *inout_mode
1308 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1309 /* The insn we have emitted. */
1312 /* An ASM with no outputs needs to be treated as volatile, for now. */
1316 if (current_function_check_memory_usage)
1318 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1322 #ifdef MD_ASM_CLOBBERS
1323 /* Sometimes we wish to automatically clobber registers across an asm.
1324 Case in point is when the i386 backend moved from cc0 to a hard reg --
1325 maintaining source-level compatability means automatically clobbering
1326 the flags register. */
1327 MD_ASM_CLOBBERS (clobbers);
1330 if (current_function_check_memory_usage)
1332 error ("`asm' cannot be used in function where memory usage is checked");
1336 /* Count the number of meaningful clobbered registers, ignoring what
1337 we would ignore later. */
1339 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1341 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1342 i = decode_reg_name (regname);
1343 if (i >= 0 || i == -4)
1346 error ("unknown register name `%s' in `asm'", regname);
1351 /* Check that the number of alternatives is constant across all
1353 if (outputs || inputs)
1355 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1356 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1359 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1361 error ("too many alternatives in `asm'");
1368 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1369 if (n_occurrences (',', constraint) != nalternatives)
1371 error ("operand constraints for `asm' differ in number of alternatives");
1374 if (TREE_CHAIN (tmp))
1375 tmp = TREE_CHAIN (tmp);
1377 tmp = next, next = 0;
1381 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1383 tree val = TREE_VALUE (tail);
1384 tree type = TREE_TYPE (val);
1393 /* If there's an erroneous arg, emit no insn. */
1394 if (TREE_TYPE (val) == error_mark_node)
1397 /* Make sure constraint has `=' and does not have `+'. Also, see
1398 if it allows any register. Be liberal on the latter test, since
1399 the worst that happens if we get it wrong is we issue an error
1402 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1403 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1405 /* Allow the `=' or `+' to not be at the beginning of the string,
1406 since it wasn't explicitly documented that way, and there is a
1407 large body of code that puts it last. Swap the character to
1408 the front, so as not to uglify any place else. */
1412 if ((p = strchr (constraint, '=')) != NULL)
1414 if ((p = strchr (constraint, '+')) != NULL)
1417 error ("output operand constraint lacks `='");
1421 if (p != constraint)
1424 bcopy (constraint, constraint+1, p-constraint);
1427 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1430 is_inout = constraint[0] == '+';
1431 /* Replace '+' with '='. */
1432 constraint[0] = '=';
1433 /* Make sure we can specify the matching operand. */
1434 if (is_inout && i > 9)
1436 error ("output operand constraint %d contains `+'", i);
1440 for (j = 1; j < c_len; j++)
1441 switch (constraint[j])
1445 error ("operand constraint contains '+' or '=' at illegal position.");
1449 if (i + 1 == ninputs + noutputs)
1451 error ("`%%' constraint used with last operand");
1456 case '?': case '!': case '*': case '&':
1457 case 'E': case 'F': case 'G': case 'H':
1458 case 's': case 'i': case 'n':
1459 case 'I': case 'J': case 'K': case 'L': case 'M':
1460 case 'N': case 'O': case 'P': case ',':
1461 #ifdef EXTRA_CONSTRAINT
1462 case 'Q': case 'R': case 'S': case 'T': case 'U':
1466 case '0': case '1': case '2': case '3': case '4':
1467 case '5': case '6': case '7': case '8': case '9':
1468 error ("matching constraint not valid in output operand");
1471 case 'V': case 'm': case 'o':
1476 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1477 excepting those that expand_call created. So match memory
1493 /* If an output operand is not a decl or indirect ref and our constraint
1494 allows a register, make a temporary to act as an intermediate.
1495 Make the asm insn write into that, then our caller will copy it to
1496 the real output operand. Likewise for promoted variables. */
1498 real_output_rtx[i] = NULL_RTX;
1499 if ((TREE_CODE (val) == INDIRECT_REF
1501 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1502 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1503 && ! (GET_CODE (DECL_RTL (val)) == REG
1504 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1509 mark_addressable (TREE_VALUE (tail));
1512 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1513 EXPAND_MEMORY_USE_WO);
1515 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1516 error ("output number %d not directly addressable", i);
1517 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1519 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1520 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1522 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1527 output_rtx[i] = assign_temp (type, 0, 0, 0);
1528 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1533 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1534 inout_opnum[ninout++] = i;
1539 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1541 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1545 /* Make vectors for the expression-rtx and constraint strings. */
1547 argvec = rtvec_alloc (ninputs);
1548 constraints = rtvec_alloc (ninputs);
1550 body = gen_rtx_ASM_OPERANDS (VOIDmode,
1551 TREE_STRING_POINTER (string), "", 0, argvec,
1552 constraints, filename, line);
1554 MEM_VOLATILE_P (body) = vol;
1556 /* Eval the inputs and put them into ARGVEC.
1557 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1560 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1563 int allows_reg = 0, allows_mem = 0;
1564 char *constraint, *orig_constraint;
1568 /* If there's an erroneous arg, emit no insn,
1569 because the ASM_INPUT would get VOIDmode
1570 and that could cause a crash in reload. */
1571 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1574 /* ??? Can this happen, and does the error message make any sense? */
1575 if (TREE_PURPOSE (tail) == NULL_TREE)
1577 error ("hard register `%s' listed as input operand to `asm'",
1578 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1582 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1583 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1584 orig_constraint = constraint;
1586 /* Make sure constraint has neither `=', `+', nor '&'. */
1588 for (j = 0; j < c_len; j++)
1589 switch (constraint[j])
1591 case '+': case '=': case '&':
1592 if (constraint == orig_constraint)
1594 error ("input operand constraint contains `%c'", constraint[j]);
1600 if (constraint == orig_constraint
1601 && i + 1 == ninputs - ninout)
1603 error ("`%%' constraint used with last operand");
1608 case 'V': case 'm': case 'o':
1613 case '?': case '!': case '*':
1614 case 'E': case 'F': case 'G': case 'H': case 'X':
1615 case 's': case 'i': case 'n':
1616 case 'I': case 'J': case 'K': case 'L': case 'M':
1617 case 'N': case 'O': case 'P': case ',':
1618 #ifdef EXTRA_CONSTRAINT
1619 case 'Q': case 'R': case 'S': case 'T': case 'U':
1623 /* Whether or not a numeric constraint allows a register is
1624 decided by the matching constraint, and so there is no need
1625 to do anything special with them. We must handle them in
1626 the default case, so that we don't unnecessarily force
1627 operands to memory. */
1628 case '0': case '1': case '2': case '3': case '4':
1629 case '5': case '6': case '7': case '8': case '9':
1630 if (constraint[j] >= '0' + noutputs)
1633 ("matching constraint references invalid operand number");
1637 /* Try and find the real constraint for this dup. */
1638 if ((j == 0 && c_len == 1)
1639 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1642 for (j = constraint[j] - '0'; j > 0; --j)
1645 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1;
1646 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1651 /* ... fall through ... */
1664 if (! allows_reg && allows_mem)
1665 mark_addressable (TREE_VALUE (tail));
1667 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1669 if (asm_operand_ok (op, constraint) <= 0)
1672 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1673 else if (!allows_mem)
1674 warning ("asm operand %d probably doesn't match constraints", i);
1675 else if (CONSTANT_P (op))
1676 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1678 else if (GET_CODE (op) == REG
1679 || GET_CODE (op) == SUBREG
1680 || GET_CODE (op) == CONCAT)
1682 tree type = TREE_TYPE (TREE_VALUE (tail));
1683 rtx memloc = assign_temp (type, 1, 1, 1);
1685 emit_move_insn (memloc, op);
1688 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1689 /* We won't recognize volatile memory as available a
1690 memory_operand at this point. Ignore it. */
1692 else if (queued_subexp_p (op))
1695 /* ??? Leave this only until we have experience with what
1696 happens in combine and elsewhere when constraints are
1698 warning ("asm operand %d probably doesn't match constraints", i);
1700 XVECEXP (body, 3, i) = op;
1702 XVECEXP (body, 4, i) /* constraints */
1703 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1708 /* Protect all the operands from the queue,
1709 now that they have all been evaluated. */
1711 for (i = 0; i < ninputs - ninout; i++)
1712 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1714 for (i = 0; i < noutputs; i++)
1715 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1717 /* For in-out operands, copy output rtx to input rtx. */
1718 for (i = 0; i < ninout; i++)
1720 static char match[9+1][2]
1721 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1722 int j = inout_opnum[i];
1724 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1726 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1727 = gen_rtx_ASM_INPUT (inout_mode[i], match[j]);
1730 /* Now, for each output, construct an rtx
1731 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1732 ARGVEC CONSTRAINTS))
1733 If there is more than one, put them inside a PARALLEL. */
1735 if (noutputs == 1 && nclobbers == 0)
1737 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1738 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1740 else if (noutputs == 0 && nclobbers == 0)
1742 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1743 insn = emit_insn (body);
1749 if (num == 0) num = 1;
1750 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1752 /* For each output operand, store a SET. */
1754 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1756 XVECEXP (body, 0, i)
1757 = gen_rtx_SET (VOIDmode,
1759 gen_rtx_ASM_OPERANDS
1761 TREE_STRING_POINTER (string),
1762 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1763 i, argvec, constraints,
1766 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1769 /* If there are no outputs (but there are some clobbers)
1770 store the bare ASM_OPERANDS into the PARALLEL. */
1773 XVECEXP (body, 0, i++) = obody;
1775 /* Store (clobber REG) for each clobbered register specified. */
1777 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1779 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1780 int j = decode_reg_name (regname);
1784 if (j == -3) /* `cc', which is not a register */
1787 if (j == -4) /* `memory', don't cache memory across asm */
1789 XVECEXP (body, 0, i++)
1790 = gen_rtx_CLOBBER (VOIDmode,
1793 gen_rtx_SCRATCH (VOIDmode)));
1797 /* Ignore unknown register, error already signaled. */
1801 /* Use QImode since that's guaranteed to clobber just one reg. */
1802 XVECEXP (body, 0, i++)
1803 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1806 insn = emit_insn (body);
1809 /* For any outputs that needed reloading into registers, spill them
1810 back to where they belong. */
1811 for (i = 0; i < noutputs; ++i)
1812 if (real_output_rtx[i])
1813 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1818 /* Generate RTL to evaluate the expression EXP
1819 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1822 expand_expr_stmt (exp)
1825 /* If -W, warn about statements with no side effects,
1826 except for an explicit cast to void (e.g. for assert()), and
1827 except inside a ({...}) where they may be useful. */
1828 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1830 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1831 && !(TREE_CODE (exp) == CONVERT_EXPR
1832 && TREE_TYPE (exp) == void_type_node))
1833 warning_with_file_and_line (emit_filename, emit_lineno,
1834 "statement with no effect");
1835 else if (warn_unused)
1836 warn_if_unused_value (exp);
1839 /* If EXP is of function type and we are expanding statements for
1840 value, convert it to pointer-to-function. */
1841 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1842 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1844 last_expr_type = TREE_TYPE (exp);
1845 last_expr_value = expand_expr (exp,
1846 (expr_stmts_for_value
1847 ? NULL_RTX : const0_rtx),
1850 /* If all we do is reference a volatile value in memory,
1851 copy it to a register to be sure it is actually touched. */
1852 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1853 && TREE_THIS_VOLATILE (exp))
1855 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1857 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1858 copy_to_reg (last_expr_value);
1861 rtx lab = gen_label_rtx ();
1863 /* Compare the value with itself to reference it. */
1864 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1865 expand_expr (TYPE_SIZE (last_expr_type),
1866 NULL_RTX, VOIDmode, 0),
1868 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1874 /* If this expression is part of a ({...}) and is in memory, we may have
1875 to preserve temporaries. */
1876 preserve_temp_slots (last_expr_value);
1878 /* Free any temporaries used to evaluate this expression. Any temporary
1879 used as a result of this expression will already have been preserved
1886 /* Warn if EXP contains any computations whose results are not used.
1887 Return 1 if a warning is printed; 0 otherwise. */
1890 warn_if_unused_value (exp)
1893 if (TREE_USED (exp))
1896 switch (TREE_CODE (exp))
1898 case PREINCREMENT_EXPR:
1899 case POSTINCREMENT_EXPR:
1900 case PREDECREMENT_EXPR:
1901 case POSTDECREMENT_EXPR:
1906 case METHOD_CALL_EXPR:
1908 case TRY_CATCH_EXPR:
1909 case WITH_CLEANUP_EXPR:
1911 /* We don't warn about COND_EXPR because it may be a useful
1912 construct if either arm contains a side effect. */
1917 /* For a binding, warn if no side effect within it. */
1918 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1921 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1923 case TRUTH_ORIF_EXPR:
1924 case TRUTH_ANDIF_EXPR:
1925 /* In && or ||, warn if 2nd operand has no side effect. */
1926 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1929 if (TREE_NO_UNUSED_WARNING (exp))
1931 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1933 /* Let people do `(foo (), 0)' without a warning. */
1934 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1936 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1940 case NON_LVALUE_EXPR:
1941 /* Don't warn about values cast to void. */
1942 if (TREE_TYPE (exp) == void_type_node)
1944 /* Don't warn about conversions not explicit in the user's program. */
1945 if (TREE_NO_UNUSED_WARNING (exp))
1947 /* Assignment to a cast usually results in a cast of a modify.
1948 Don't complain about that. There can be an arbitrary number of
1949 casts before the modify, so we must loop until we find the first
1950 non-cast expression and then test to see if that is a modify. */
1952 tree tem = TREE_OPERAND (exp, 0);
1954 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1955 tem = TREE_OPERAND (tem, 0);
1957 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1958 || TREE_CODE (tem) == CALL_EXPR)
1964 /* Don't warn about automatic dereferencing of references, since
1965 the user cannot control it. */
1966 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1967 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1968 /* ... fall through ... */
1971 /* Referencing a volatile value is a side effect, so don't warn. */
1972 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1973 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1974 && TREE_THIS_VOLATILE (exp))
1977 warning_with_file_and_line (emit_filename, emit_lineno,
1978 "value computed is not used");
1983 /* Clear out the memory of the last expression evaluated. */
1991 /* Begin a statement which will return a value.
1992 Return the RTL_EXPR for this statement expr.
1993 The caller must save that value and pass it to expand_end_stmt_expr. */
1996 expand_start_stmt_expr ()
2001 /* Make the RTL_EXPR node temporary, not momentary,
2002 so that rtl_expr_chain doesn't become garbage. */
2003 momentary = suspend_momentary ();
2004 t = make_node (RTL_EXPR);
2005 resume_momentary (momentary);
2006 do_pending_stack_adjust ();
2007 start_sequence_for_rtl_expr (t);
2009 expr_stmts_for_value++;
2013 /* Restore the previous state at the end of a statement that returns a value.
2014 Returns a tree node representing the statement's value and the
2015 insns to compute the value.
2017 The nodes of that expression have been freed by now, so we cannot use them.
2018 But we don't want to do that anyway; the expression has already been
2019 evaluated and now we just want to use the value. So generate a RTL_EXPR
2020 with the proper type and RTL value.
2022 If the last substatement was not an expression,
2023 return something with type `void'. */
2026 expand_end_stmt_expr (t)
2031 if (last_expr_type == 0)
2033 last_expr_type = void_type_node;
2034 last_expr_value = const0_rtx;
2036 else if (last_expr_value == 0)
2037 /* There are some cases where this can happen, such as when the
2038 statement is void type. */
2039 last_expr_value = const0_rtx;
2040 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2041 /* Remove any possible QUEUED. */
2042 last_expr_value = protect_from_queue (last_expr_value, 0);
2046 TREE_TYPE (t) = last_expr_type;
2047 RTL_EXPR_RTL (t) = last_expr_value;
2048 RTL_EXPR_SEQUENCE (t) = get_insns ();
2050 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2054 /* Don't consider deleting this expr or containing exprs at tree level. */
2055 TREE_SIDE_EFFECTS (t) = 1;
2056 /* Propagate volatility of the actual RTL expr. */
2057 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2060 expr_stmts_for_value--;
2065 /* Generate RTL for the start of an if-then. COND is the expression
2066 whose truth should be tested.
2068 If EXITFLAG is nonzero, this conditional is visible to
2069 `exit_something'. */
2072 expand_start_cond (cond, exitflag)
2076 struct nesting *thiscond = ALLOC_NESTING ();
2078 /* Make an entry on cond_stack for the cond we are entering. */
2080 thiscond->next = cond_stack;
2081 thiscond->all = nesting_stack;
2082 thiscond->depth = ++nesting_depth;
2083 thiscond->data.cond.next_label = gen_label_rtx ();
2084 /* Before we encounter an `else', we don't need a separate exit label
2085 unless there are supposed to be exit statements
2086 to exit this conditional. */
2087 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2088 thiscond->data.cond.endif_label = thiscond->exit_label;
2089 cond_stack = thiscond;
2090 nesting_stack = thiscond;
2092 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2095 /* Generate RTL between then-clause and the elseif-clause
2096 of an if-then-elseif-.... */
2099 expand_start_elseif (cond)
2102 if (cond_stack->data.cond.endif_label == 0)
2103 cond_stack->data.cond.endif_label = gen_label_rtx ();
2104 emit_jump (cond_stack->data.cond.endif_label);
2105 emit_label (cond_stack->data.cond.next_label);
2106 cond_stack->data.cond.next_label = gen_label_rtx ();
2107 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2110 /* Generate RTL between the then-clause and the else-clause
2111 of an if-then-else. */
2114 expand_start_else ()
2116 if (cond_stack->data.cond.endif_label == 0)
2117 cond_stack->data.cond.endif_label = gen_label_rtx ();
2119 emit_jump (cond_stack->data.cond.endif_label);
2120 emit_label (cond_stack->data.cond.next_label);
2121 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2124 /* After calling expand_start_else, turn this "else" into an "else if"
2125 by providing another condition. */
2128 expand_elseif (cond)
2131 cond_stack->data.cond.next_label = gen_label_rtx ();
2132 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2135 /* Generate RTL for the end of an if-then.
2136 Pop the record for it off of cond_stack. */
2141 struct nesting *thiscond = cond_stack;
2143 do_pending_stack_adjust ();
2144 if (thiscond->data.cond.next_label)
2145 emit_label (thiscond->data.cond.next_label);
2146 if (thiscond->data.cond.endif_label)
2147 emit_label (thiscond->data.cond.endif_label);
2149 POPSTACK (cond_stack);
2155 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2156 loop should be exited by `exit_something'. This is a loop for which
2157 `expand_continue' will jump to the top of the loop.
2159 Make an entry on loop_stack to record the labels associated with
2163 expand_start_loop (exit_flag)
2166 register struct nesting *thisloop = ALLOC_NESTING ();
2168 /* Make an entry on loop_stack for the loop we are entering. */
2170 thisloop->next = loop_stack;
2171 thisloop->all = nesting_stack;
2172 thisloop->depth = ++nesting_depth;
2173 thisloop->data.loop.start_label = gen_label_rtx ();
2174 thisloop->data.loop.end_label = gen_label_rtx ();
2175 thisloop->data.loop.alt_end_label = 0;
2176 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2177 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2178 loop_stack = thisloop;
2179 nesting_stack = thisloop;
2181 do_pending_stack_adjust ();
2183 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2184 emit_label (thisloop->data.loop.start_label);
2189 /* Like expand_start_loop but for a loop where the continuation point
2190 (for expand_continue_loop) will be specified explicitly. */
2193 expand_start_loop_continue_elsewhere (exit_flag)
2196 struct nesting *thisloop = expand_start_loop (exit_flag);
2197 loop_stack->data.loop.continue_label = gen_label_rtx ();
2201 /* Specify the continuation point for a loop started with
2202 expand_start_loop_continue_elsewhere.
2203 Use this at the point in the code to which a continue statement
2207 expand_loop_continue_here ()
2209 do_pending_stack_adjust ();
2210 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2211 emit_label (loop_stack->data.loop.continue_label);
2214 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2215 Pop the block off of loop_stack. */
2220 rtx start_label = loop_stack->data.loop.start_label;
2221 rtx insn = get_last_insn ();
2222 int needs_end_jump = 1;
2224 /* Mark the continue-point at the top of the loop if none elsewhere. */
2225 if (start_label == loop_stack->data.loop.continue_label)
2226 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2228 do_pending_stack_adjust ();
2230 /* If optimizing, perhaps reorder the loop.
2231 First, try to use a condjump near the end.
2232 expand_exit_loop_if_false ends loops with unconditional jumps,
2235 if (test) goto label;
2237 goto loop_stack->data.loop.end_label
2241 If we find such a pattern, we can end the loop earlier. */
2244 && GET_CODE (insn) == CODE_LABEL
2245 && LABEL_NAME (insn) == NULL
2246 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2249 rtx jump = PREV_INSN (PREV_INSN (label));
2251 if (GET_CODE (jump) == JUMP_INSN
2252 && GET_CODE (PATTERN (jump)) == SET
2253 && SET_DEST (PATTERN (jump)) == pc_rtx
2254 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2255 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2256 == loop_stack->data.loop.end_label))
2260 /* The test might be complex and reference LABEL multiple times,
2261 like the loop in loop_iterations to set vtop. To handle this,
2263 insn = PREV_INSN (label);
2264 reorder_insns (label, label, start_label);
2266 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2268 /* We ignore line number notes, but if we see any other note,
2269 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2270 NOTE_INSN_LOOP_*, we disable this optimization. */
2271 if (GET_CODE (prev) == NOTE)
2273 if (NOTE_LINE_NUMBER (prev) < 0)
2277 if (GET_CODE (prev) == CODE_LABEL)
2279 if (GET_CODE (prev) == JUMP_INSN)
2281 if (GET_CODE (PATTERN (prev)) == SET
2282 && SET_DEST (PATTERN (prev)) == pc_rtx
2283 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2284 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2286 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2288 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2290 emit_note_after (NOTE_INSN_LOOP_END, prev);
2299 /* If the loop starts with a loop exit, roll that to the end where
2300 it will optimize together with the jump back.
2302 We look for the conditional branch to the exit, except that once
2303 we find such a branch, we don't look past 30 instructions.
2305 In more detail, if the loop presently looks like this (in pseudo-C):
2308 if (test) goto end_label;
2313 transform it to look like:
2319 if (test) goto end_label;
2320 goto newstart_label;
2323 Here, the `test' may actually consist of some reasonably complex
2324 code, terminating in a test. */
2329 ! (GET_CODE (insn) == JUMP_INSN
2330 && GET_CODE (PATTERN (insn)) == SET
2331 && SET_DEST (PATTERN (insn)) == pc_rtx
2332 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2336 rtx last_test_insn = NULL_RTX;
2338 /* Scan insns from the top of the loop looking for a qualified
2339 conditional exit. */
2340 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2341 insn = NEXT_INSN (insn))
2343 if (GET_CODE (insn) == NOTE)
2346 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2347 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2348 /* The code that actually moves the exit test will
2349 carefully leave BLOCK notes in their original
2350 location. That means, however, that we can't debug
2351 the exit test itself. So, we refuse to move code
2352 containing BLOCK notes at low optimization levels. */
2355 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2357 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2361 /* We've come to the end of an EH region, but
2362 never saw the beginning of that region. That
2363 means that an EH region begins before the top
2364 of the loop, and ends in the middle of it. The
2365 existence of such a situation violates a basic
2366 assumption in this code, since that would imply
2367 that even when EH_REGIONS is zero, we might
2368 move code out of an exception region. */
2372 /* We must not walk into a nested loop. */
2373 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2376 /* We already know this INSN is a NOTE, so there's no
2377 point in looking at it to see if it's a JUMP. */
2381 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2384 if (last_test_insn && num_insns > 30)
2388 /* We don't want to move a partial EH region. Consider:
2402 This isn't legal C++, but here's what it's supposed to
2403 mean: if cond() is true, stop looping. Otherwise,
2404 call bar, and keep looping. In addition, if cond
2405 throws an exception, catch it and keep looping. Such
2406 constructs are certainy legal in LISP.
2408 We should not move the `if (cond()) 0' test since then
2409 the EH-region for the try-block would be broken up.
2410 (In this case we would the EH_BEG note for the `try'
2411 and `if cond()' but not the call to bar() or the
2414 So we don't look for tests within an EH region. */
2417 if (GET_CODE (insn) == JUMP_INSN
2418 && GET_CODE (PATTERN (insn)) == SET
2419 && SET_DEST (PATTERN (insn)) == pc_rtx)
2421 /* This is indeed a jump. */
2422 rtx dest1 = NULL_RTX;
2423 rtx dest2 = NULL_RTX;
2424 rtx potential_last_test;
2425 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2427 /* A conditional jump. */
2428 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2429 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2430 potential_last_test = insn;
2434 /* An unconditional jump. */
2435 dest1 = SET_SRC (PATTERN (insn));
2436 /* Include the BARRIER after the JUMP. */
2437 potential_last_test = NEXT_INSN (insn);
2441 if (dest1 && GET_CODE (dest1) == LABEL_REF
2442 && ((XEXP (dest1, 0)
2443 == loop_stack->data.loop.alt_end_label)
2445 == loop_stack->data.loop.end_label)))
2447 last_test_insn = potential_last_test;
2451 /* If this was a conditional jump, there may be
2452 another label at which we should look. */
2459 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2461 /* We found one. Move everything from there up
2462 to the end of the loop, and add a jump into the loop
2463 to jump to there. */
2464 register rtx newstart_label = gen_label_rtx ();
2465 register rtx start_move = start_label;
2468 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2469 then we want to move this note also. */
2470 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2471 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2472 == NOTE_INSN_LOOP_CONT))
2473 start_move = PREV_INSN (start_move);
2475 emit_label_after (newstart_label, PREV_INSN (start_move));
2477 /* Actually move the insns. Start at the beginning, and
2478 keep copying insns until we've copied the
2480 for (insn = start_move; insn; insn = next_insn)
2482 /* Figure out which insn comes after this one. We have
2483 to do this before we move INSN. */
2484 if (insn == last_test_insn)
2485 /* We've moved all the insns. */
2486 next_insn = NULL_RTX;
2488 next_insn = NEXT_INSN (insn);
2490 if (GET_CODE (insn) == NOTE
2491 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2492 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2493 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2494 NOTE_INSN_BLOCK_ENDs because the correct generation
2495 of debugging information depends on these appearing
2496 in the same order in the RTL and in the tree
2497 structure, where they are represented as BLOCKs.
2498 So, we don't move block notes. Of course, moving
2499 the code inside the block is likely to make it
2500 impossible to debug the instructions in the exit
2501 test, but such is the price of optimization. */
2504 /* Move the INSN. */
2505 reorder_insns (insn, insn, get_last_insn ());
2508 emit_jump_insn_after (gen_jump (start_label),
2509 PREV_INSN (newstart_label));
2510 emit_barrier_after (PREV_INSN (newstart_label));
2511 start_label = newstart_label;
2517 emit_jump (start_label);
2518 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2520 emit_label (loop_stack->data.loop.end_label);
2522 POPSTACK (loop_stack);
2527 /* Generate a jump to the current loop's continue-point.
2528 This is usually the top of the loop, but may be specified
2529 explicitly elsewhere. If not currently inside a loop,
2530 return 0 and do nothing; caller will print an error message. */
2533 expand_continue_loop (whichloop)
2534 struct nesting *whichloop;
2538 whichloop = loop_stack;
2541 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2546 /* Generate a jump to exit the current loop. If not currently inside a loop,
2547 return 0 and do nothing; caller will print an error message. */
2550 expand_exit_loop (whichloop)
2551 struct nesting *whichloop;
2555 whichloop = loop_stack;
2558 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2562 /* Generate a conditional jump to exit the current loop if COND
2563 evaluates to zero. If not currently inside a loop,
2564 return 0 and do nothing; caller will print an error message. */
2567 expand_exit_loop_if_false (whichloop, cond)
2568 struct nesting *whichloop;
2571 rtx label = gen_label_rtx ();
2576 whichloop = loop_stack;
2579 /* In order to handle fixups, we actually create a conditional jump
2580 around a unconditional branch to exit the loop. If fixups are
2581 necessary, they go before the unconditional branch. */
2584 do_jump (cond, NULL_RTX, label);
2585 last_insn = get_last_insn ();
2586 if (GET_CODE (last_insn) == CODE_LABEL)
2587 whichloop->data.loop.alt_end_label = last_insn;
2588 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2595 /* Return nonzero if the loop nest is empty. Else return zero. */
2598 stmt_loop_nest_empty ()
2600 return (loop_stack == NULL);
2603 /* Return non-zero if we should preserve sub-expressions as separate
2604 pseudos. We never do so if we aren't optimizing. We always do so
2605 if -fexpensive-optimizations.
2607 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2608 the loop may still be a small one. */
2611 preserve_subexpressions_p ()
2615 if (flag_expensive_optimizations)
2618 if (optimize == 0 || current_function == 0
2619 || current_function->stmt == 0 || loop_stack == 0)
2622 insn = get_last_insn_anywhere ();
2625 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2626 < n_non_fixed_regs * 3));
2630 /* Generate a jump to exit the current loop, conditional, binding contour
2631 or case statement. Not all such constructs are visible to this function,
2632 only those started with EXIT_FLAG nonzero. Individual languages use
2633 the EXIT_FLAG parameter to control which kinds of constructs you can
2636 If not currently inside anything that can be exited,
2637 return 0 and do nothing; caller will print an error message. */
2640 expand_exit_something ()
2644 for (n = nesting_stack; n; n = n->all)
2645 if (n->exit_label != 0)
2647 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2654 /* Generate RTL to return from the current function, with no value.
2655 (That is, we do not do anything about returning any value.) */
2658 expand_null_return ()
2660 struct nesting *block = block_stack;
2663 /* Does any pending block have cleanups? */
2665 while (block && block->data.block.cleanups == 0)
2666 block = block->next;
2668 /* If yes, use a goto to return, since that runs cleanups. */
2670 expand_null_return_1 (last_insn, block != 0);
2673 /* Generate RTL to return from the current function, with value VAL. */
2676 expand_value_return (val)
2679 struct nesting *block = block_stack;
2680 rtx last_insn = get_last_insn ();
2681 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2683 /* Copy the value to the return location
2684 unless it's already there. */
2686 if (return_reg != val)
2688 #ifdef PROMOTE_FUNCTION_RETURN
2689 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2690 int unsignedp = TREE_UNSIGNED (type);
2691 enum machine_mode mode
2692 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2695 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2696 convert_move (return_reg, val, unsignedp);
2699 emit_move_insn (return_reg, val);
2701 if (GET_CODE (return_reg) == REG
2702 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2703 emit_insn (gen_rtx_USE (VOIDmode, return_reg));
2704 /* Handle calls that return values in multiple non-contiguous locations.
2705 The Irix 6 ABI has examples of this. */
2706 else if (GET_CODE (return_reg) == PARALLEL)
2710 for (i = 0; i < XVECLEN (return_reg, 0); i++)
2712 rtx x = XEXP (XVECEXP (return_reg, 0, i), 0);
2714 if (GET_CODE (x) == REG
2715 && REGNO (x) < FIRST_PSEUDO_REGISTER)
2716 emit_insn (gen_rtx_USE (VOIDmode, x));
2720 /* Does any pending block have cleanups? */
2722 while (block && block->data.block.cleanups == 0)
2723 block = block->next;
2725 /* If yes, use a goto to return, since that runs cleanups.
2726 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2728 expand_null_return_1 (last_insn, block != 0);
2731 /* Output a return with no value. If LAST_INSN is nonzero,
2732 pretend that the return takes place after LAST_INSN.
2733 If USE_GOTO is nonzero then don't use a return instruction;
2734 go to the return label instead. This causes any cleanups
2735 of pending blocks to be executed normally. */
2738 expand_null_return_1 (last_insn, use_goto)
2742 rtx end_label = cleanup_label ? cleanup_label : return_label;
2744 clear_pending_stack_adjust ();
2745 do_pending_stack_adjust ();
2748 /* PCC-struct return always uses an epilogue. */
2749 if (current_function_returns_pcc_struct || use_goto)
2752 end_label = return_label = gen_label_rtx ();
2753 expand_goto_internal (NULL_TREE, end_label, last_insn);
2757 /* Otherwise output a simple return-insn if one is available,
2758 unless it won't do the job. */
2760 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2762 emit_jump_insn (gen_return ());
2768 /* Otherwise jump to the epilogue. */
2769 expand_goto_internal (NULL_TREE, end_label, last_insn);
2772 /* Generate RTL to evaluate the expression RETVAL and return it
2773 from the current function. */
2776 expand_return (retval)
2779 /* If there are any cleanups to be performed, then they will
2780 be inserted following LAST_INSN. It is desirable
2781 that the last_insn, for such purposes, should be the
2782 last insn before computing the return value. Otherwise, cleanups
2783 which call functions can clobber the return value. */
2784 /* ??? rms: I think that is erroneous, because in C++ it would
2785 run destructors on variables that might be used in the subsequent
2786 computation of the return value. */
2788 register rtx val = 0;
2793 /* If function wants no value, give it none. */
2794 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2796 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2798 expand_null_return ();
2802 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2803 /* This is not sufficient. We also need to watch for cleanups of the
2804 expression we are about to expand. Unfortunately, we cannot know
2805 if it has cleanups until we expand it, and we want to change how we
2806 expand it depending upon if we need cleanups. We can't win. */
2808 cleanups = any_pending_cleanups (1);
2813 if (TREE_CODE (retval) == RESULT_DECL)
2814 retval_rhs = retval;
2815 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2816 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2817 retval_rhs = TREE_OPERAND (retval, 1);
2818 else if (TREE_TYPE (retval) == void_type_node)
2819 /* Recognize tail-recursive call to void function. */
2820 retval_rhs = retval;
2822 retval_rhs = NULL_TREE;
2824 /* Only use `last_insn' if there are cleanups which must be run. */
2825 if (cleanups || cleanup_label != 0)
2826 last_insn = get_last_insn ();
2828 /* Distribute return down conditional expr if either of the sides
2829 may involve tail recursion (see test below). This enhances the number
2830 of tail recursions we see. Don't do this always since it can produce
2831 sub-optimal code in some cases and we distribute assignments into
2832 conditional expressions when it would help. */
2834 if (optimize && retval_rhs != 0
2835 && frame_offset == 0
2836 && TREE_CODE (retval_rhs) == COND_EXPR
2837 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2838 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2840 rtx label = gen_label_rtx ();
2843 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2844 start_cleanup_deferral ();
2845 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2846 DECL_RESULT (current_function_decl),
2847 TREE_OPERAND (retval_rhs, 1));
2848 TREE_SIDE_EFFECTS (expr) = 1;
2849 expand_return (expr);
2852 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2853 DECL_RESULT (current_function_decl),
2854 TREE_OPERAND (retval_rhs, 2));
2855 TREE_SIDE_EFFECTS (expr) = 1;
2856 expand_return (expr);
2857 end_cleanup_deferral ();
2861 /* Attempt to optimize the call if it is tail recursive. */
2862 if (optimize_tail_recursion (retval_rhs, last_insn))
2866 /* This optimization is safe if there are local cleanups
2867 because expand_null_return takes care of them.
2868 ??? I think it should also be safe when there is a cleanup label,
2869 because expand_null_return takes care of them, too.
2870 Any reason why not? */
2871 if (HAVE_return && cleanup_label == 0
2872 && ! current_function_returns_pcc_struct
2873 && BRANCH_COST <= 1)
2875 /* If this is return x == y; then generate
2876 if (x == y) return 1; else return 0;
2877 if we can do it with explicit return insns and branches are cheap,
2878 but not if we have the corresponding scc insn. */
2881 switch (TREE_CODE (retval_rhs))
2907 case TRUTH_ANDIF_EXPR:
2908 case TRUTH_ORIF_EXPR:
2909 case TRUTH_AND_EXPR:
2911 case TRUTH_NOT_EXPR:
2912 case TRUTH_XOR_EXPR:
2915 op0 = gen_label_rtx ();
2916 jumpifnot (retval_rhs, op0);
2917 expand_value_return (const1_rtx);
2919 expand_value_return (const0_rtx);
2928 #endif /* HAVE_return */
2930 /* If the result is an aggregate that is being returned in one (or more)
2931 registers, load the registers here. The compiler currently can't handle
2932 copying a BLKmode value into registers. We could put this code in a
2933 more general area (for use by everyone instead of just function
2934 call/return), but until this feature is generally usable it is kept here
2935 (and in expand_call). The value must go into a pseudo in case there
2936 are cleanups that will clobber the real return register. */
2939 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2940 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2942 int i, bitpos, xbitpos;
2943 int big_endian_correction = 0;
2944 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2945 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2946 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2947 (unsigned int)BITS_PER_WORD);
2948 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2949 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2950 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2951 enum machine_mode tmpmode, result_reg_mode;
2953 /* Structures whose size is not a multiple of a word are aligned
2954 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2955 machine, this means we must skip the empty high order bytes when
2956 calculating the bit offset. */
2957 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2958 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2961 /* Copy the structure BITSIZE bits at a time. */
2962 for (bitpos = 0, xbitpos = big_endian_correction;
2963 bitpos < bytes * BITS_PER_UNIT;
2964 bitpos += bitsize, xbitpos += bitsize)
2966 /* We need a new destination pseudo each time xbitpos is
2967 on a word boundary and when xbitpos == big_endian_correction
2968 (the first time through). */
2969 if (xbitpos % BITS_PER_WORD == 0
2970 || xbitpos == big_endian_correction)
2972 /* Generate an appropriate register. */
2973 dst = gen_reg_rtx (word_mode);
2974 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2976 /* Clobber the destination before we move anything into it. */
2977 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2980 /* We need a new source operand each time bitpos is on a word
2982 if (bitpos % BITS_PER_WORD == 0)
2983 src = operand_subword_force (result_val,
2984 bitpos / BITS_PER_WORD,
2987 /* Use bitpos for the source extraction (left justified) and
2988 xbitpos for the destination store (right justified). */
2989 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2990 extract_bit_field (src, bitsize,
2991 bitpos % BITS_PER_WORD, 1,
2992 NULL_RTX, word_mode,
2994 bitsize / BITS_PER_UNIT,
2996 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2999 /* Find the smallest integer mode large enough to hold the
3000 entire structure and use that mode instead of BLKmode
3001 on the USE insn for the return register. */
3002 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3003 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3004 tmpmode != VOIDmode;
3005 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3007 /* Have we found a large enough mode? */
3008 if (GET_MODE_SIZE (tmpmode) >= bytes)
3012 /* No suitable mode found. */
3013 if (tmpmode == VOIDmode)
3016 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
3018 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3019 result_reg_mode = word_mode;
3021 result_reg_mode = tmpmode;
3022 result_reg = gen_reg_rtx (result_reg_mode);
3025 for (i = 0; i < n_regs; i++)
3026 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3029 if (tmpmode != result_reg_mode)
3030 result_reg = gen_lowpart (tmpmode, result_reg);
3032 expand_value_return (result_reg);
3036 && TREE_TYPE (retval_rhs) != void_type_node
3037 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
3039 /* Calculate the return value into a pseudo reg. */
3040 val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl)));
3041 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3042 val = force_not_mem (val);
3044 /* Return the calculated value, doing cleanups first. */
3045 expand_value_return (val);
3049 /* No cleanups or no hard reg used;
3050 calculate value into hard return reg. */
3051 expand_expr (retval, const0_rtx, VOIDmode, 0);
3053 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
3057 /* Return 1 if the end of the generated RTX is not a barrier.
3058 This means code already compiled can drop through. */
3061 drop_through_at_end_p ()
3063 rtx insn = get_last_insn ();
3064 while (insn && GET_CODE (insn) == NOTE)
3065 insn = PREV_INSN (insn);
3066 return insn && GET_CODE (insn) != BARRIER;
3069 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3070 and emit code to optimize the tail recursion. LAST_INSN indicates where
3071 to place the jump to the tail recursion label. Return TRUE if the
3072 call was optimized into a goto.
3074 This is only used by expand_return, but expand_call is expected to
3078 optimize_tail_recursion (call_expr, last_insn)
3082 /* For tail-recursive call to current function,
3083 just jump back to the beginning.
3084 It's unsafe if any auto variable in this function
3085 has its address taken; for simplicity,
3086 require stack frame to be empty. */
3087 if (optimize && call_expr != 0
3088 && frame_offset == 0
3089 && TREE_CODE (call_expr) == CALL_EXPR
3090 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3091 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3092 /* Finish checking validity, and if valid emit code
3093 to set the argument variables for the new call. */
3094 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3095 DECL_ARGUMENTS (current_function_decl)))
3097 if (tail_recursion_label == 0)
3099 tail_recursion_label = gen_label_rtx ();
3100 emit_label_after (tail_recursion_label,
3101 tail_recursion_reentry);
3104 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3112 /* Emit code to alter this function's formal parms for a tail-recursive call.
3113 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3114 FORMALS is the chain of decls of formals.
3115 Return 1 if this can be done;
3116 otherwise return 0 and do not emit any code. */
3119 tail_recursion_args (actuals, formals)
3120 tree actuals, formals;
3122 register tree a = actuals, f = formals;
3124 register rtx *argvec;
3126 /* Check that number and types of actuals are compatible
3127 with the formals. This is not always true in valid C code.
3128 Also check that no formal needs to be addressable
3129 and that all formals are scalars. */
3131 /* Also count the args. */
3133 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3135 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3136 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3138 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3141 if (a != 0 || f != 0)
3144 /* Compute all the actuals. */
3146 argvec = (rtx *) alloca (i * sizeof (rtx));
3148 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3149 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3151 /* Find which actual values refer to current values of previous formals.
3152 Copy each of them now, before any formal is changed. */
3154 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3158 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3159 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3160 { copy = 1; break; }
3162 argvec[i] = copy_to_reg (argvec[i]);
3165 /* Store the values of the actuals into the formals. */
3167 for (f = formals, a = actuals, i = 0; f;
3168 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3170 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3171 emit_move_insn (DECL_RTL (f), argvec[i]);
3173 convert_move (DECL_RTL (f), argvec[i],
3174 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3181 /* Generate the RTL code for entering a binding contour.
3182 The variables are declared one by one, by calls to `expand_decl'.
3184 FLAGS is a bitwise or of the following flags:
3186 1 - Nonzero if this construct should be visible to
3189 2 - Nonzero if this contour does not require a
3190 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3191 language-independent code should set this flag because they
3192 will not create corresponding BLOCK nodes. (There should be
3193 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3194 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3195 when expand_end_bindings is called. */
3198 expand_start_bindings (flags)
3201 struct nesting *thisblock = ALLOC_NESTING ();
3203 int exit_flag = ((flags & 1) != 0);
3204 int block_flag = ((flags & 2) == 0);
3206 note = emit_note (NULL_PTR,
3207 block_flag ? NOTE_INSN_BLOCK_BEG : NOTE_INSN_DELETED);
3209 /* Make an entry on block_stack for the block we are entering. */
3211 thisblock->next = block_stack;
3212 thisblock->all = nesting_stack;
3213 thisblock->depth = ++nesting_depth;
3214 thisblock->data.block.stack_level = 0;
3215 thisblock->data.block.cleanups = 0;
3216 thisblock->data.block.n_function_calls = 0;
3217 thisblock->data.block.exception_region = 0;
3218 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3220 thisblock->data.block.conditional_code = 0;
3221 thisblock->data.block.last_unconditional_cleanup = note;
3222 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3225 && !(block_stack->data.block.cleanups == NULL_TREE
3226 && block_stack->data.block.outer_cleanups == NULL_TREE))
3227 thisblock->data.block.outer_cleanups
3228 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3229 block_stack->data.block.outer_cleanups);
3231 thisblock->data.block.outer_cleanups = 0;
3232 thisblock->data.block.label_chain = 0;
3233 thisblock->data.block.innermost_stack_block = stack_block_stack;
3234 thisblock->data.block.first_insn = note;
3235 thisblock->data.block.block_start_count = ++current_block_start_count;
3236 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3237 block_stack = thisblock;
3238 nesting_stack = thisblock;
3240 /* Make a new level for allocating stack slots. */
3244 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3245 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3246 expand_expr are made. After we end the region, we know that all
3247 space for all temporaries that were created by TARGET_EXPRs will be
3248 destroyed and their space freed for reuse. */
3251 expand_start_target_temps ()
3253 /* This is so that even if the result is preserved, the space
3254 allocated will be freed, as we know that it is no longer in use. */
3257 /* Start a new binding layer that will keep track of all cleanup
3258 actions to be performed. */
3259 expand_start_bindings (2);
3261 target_temp_slot_level = temp_slot_level;
3265 expand_end_target_temps ()
3267 expand_end_bindings (NULL_TREE, 0, 0);
3269 /* This is so that even if the result is preserved, the space
3270 allocated will be freed, as we know that it is no longer in use. */
3274 /* Mark top block of block_stack as an implicit binding for an
3275 exception region. This is used to prevent infinite recursion when
3276 ending a binding with expand_end_bindings. It is only ever called
3277 by expand_eh_region_start, as that it the only way to create a
3278 block stack for a exception region. */
3281 mark_block_as_eh_region ()
3283 block_stack->data.block.exception_region = 1;
3284 if (block_stack->next
3285 && block_stack->next->data.block.conditional_code)
3287 block_stack->data.block.conditional_code
3288 = block_stack->next->data.block.conditional_code;
3289 block_stack->data.block.last_unconditional_cleanup
3290 = block_stack->next->data.block.last_unconditional_cleanup;
3291 block_stack->data.block.cleanup_ptr
3292 = block_stack->next->data.block.cleanup_ptr;
3296 /* True if we are currently emitting insns in an area of output code
3297 that is controlled by a conditional expression. This is used by
3298 the cleanup handling code to generate conditional cleanup actions. */
3301 conditional_context ()
3303 return block_stack && block_stack->data.block.conditional_code;
3306 /* Mark top block of block_stack as not for an implicit binding for an
3307 exception region. This is only ever done by expand_eh_region_end
3308 to let expand_end_bindings know that it is being called explicitly
3309 to end the binding layer for just the binding layer associated with
3310 the exception region, otherwise expand_end_bindings would try and
3311 end all implicit binding layers for exceptions regions, and then
3312 one normal binding layer. */
3315 mark_block_as_not_eh_region ()
3317 block_stack->data.block.exception_region = 0;
3320 /* True if the top block of block_stack was marked as for an exception
3321 region by mark_block_as_eh_region. */
3326 return (current_function && block_stack
3327 && block_stack->data.block.exception_region);
3330 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3331 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3335 remember_end_note (block)
3336 register tree block;
3338 BLOCK_END_NOTE (block) = last_block_end_note;
3339 last_block_end_note = NULL_RTX;
3342 /* Emit a handler label for a nonlocal goto handler.
3343 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3346 expand_nl_handler_label (slot, before_insn)
3347 rtx slot, before_insn;
3350 rtx handler_label = gen_label_rtx ();
3352 /* Don't let jump_optimize delete the handler. */
3353 LABEL_PRESERVE_P (handler_label) = 1;
3356 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3357 insns = get_insns ();
3359 emit_insns_before (insns, before_insn);
3361 emit_label (handler_label);
3363 return handler_label;
3366 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3369 expand_nl_goto_receiver ()
3371 #ifdef HAVE_nonlocal_goto
3372 if (! HAVE_nonlocal_goto)
3374 /* First adjust our frame pointer to its actual value. It was
3375 previously set to the start of the virtual area corresponding to
3376 the stacked variables when we branched here and now needs to be
3377 adjusted to the actual hardware fp value.
3379 Assignments are to virtual registers are converted by
3380 instantiate_virtual_regs into the corresponding assignment
3381 to the underlying register (fp in this case) that makes
3382 the original assignment true.
3383 So the following insn will actually be
3384 decrementing fp by STARTING_FRAME_OFFSET. */
3385 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3387 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3388 if (fixed_regs[ARG_POINTER_REGNUM])
3390 #ifdef ELIMINABLE_REGS
3391 /* If the argument pointer can be eliminated in favor of the
3392 frame pointer, we don't need to restore it. We assume here
3393 that if such an elimination is present, it can always be used.
3394 This is the case on all known machines; if we don't make this
3395 assumption, we do unnecessary saving on many machines. */
3396 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3399 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3400 if (elim_regs[i].from == ARG_POINTER_REGNUM
3401 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3404 if (i == sizeof elim_regs / sizeof elim_regs [0])
3407 /* Now restore our arg pointer from the address at which it
3408 was saved in our stack frame.
3409 If there hasn't be space allocated for it yet, make
3411 if (arg_pointer_save_area == 0)
3412 arg_pointer_save_area
3413 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3414 emit_move_insn (virtual_incoming_args_rtx,
3415 /* We need a pseudo here, or else
3416 instantiate_virtual_regs_1 complains. */
3417 copy_to_reg (arg_pointer_save_area));
3422 #ifdef HAVE_nonlocal_goto_receiver
3423 if (HAVE_nonlocal_goto_receiver)
3424 emit_insn (gen_nonlocal_goto_receiver ());
3428 /* Make handlers for nonlocal gotos taking place in the function calls in
3432 expand_nl_goto_receivers (thisblock)
3433 struct nesting *thisblock;
3436 rtx afterward = gen_label_rtx ();
3441 /* Record the handler address in the stack slot for that purpose,
3442 during this block, saving and restoring the outer value. */
3443 if (thisblock->next != 0)
3444 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3446 rtx save_receiver = gen_reg_rtx (Pmode);
3447 emit_move_insn (XEXP (slot, 0), save_receiver);
3450 emit_move_insn (save_receiver, XEXP (slot, 0));
3451 insns = get_insns ();
3453 emit_insns_before (insns, thisblock->data.block.first_insn);
3456 /* Jump around the handlers; they run only when specially invoked. */
3457 emit_jump (afterward);
3459 /* Make a separate handler for each label. */
3460 link = nonlocal_labels;
3461 slot = nonlocal_goto_handler_slots;
3462 label_list = NULL_RTX;
3463 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3464 /* Skip any labels we shouldn't be able to jump to from here,
3465 we generate one special handler for all of them below which just calls
3467 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3470 lab = expand_nl_handler_label (XEXP (slot, 0),
3471 thisblock->data.block.first_insn);
3472 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3474 expand_nl_goto_receiver ();
3476 /* Jump to the "real" nonlocal label. */
3477 expand_goto (TREE_VALUE (link));
3480 /* A second pass over all nonlocal labels; this time we handle those
3481 we should not be able to jump to at this point. */
3482 link = nonlocal_labels;
3483 slot = nonlocal_goto_handler_slots;
3485 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3486 if (DECL_TOO_LATE (TREE_VALUE (link)))
3489 lab = expand_nl_handler_label (XEXP (slot, 0),
3490 thisblock->data.block.first_insn);
3491 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3497 expand_nl_goto_receiver ();
3498 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3503 nonlocal_goto_handler_labels = label_list;
3504 emit_label (afterward);
3507 /* Warn about any unused VARS (which may contain nodes other than
3508 VAR_DECLs, but such nodes are ignored). The nodes are connected
3509 via the TREE_CHAIN field. */
3512 warn_about_unused_variables (vars)
3518 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3519 if (TREE_CODE (decl) == VAR_DECL
3520 && ! TREE_USED (decl)
3521 && ! DECL_IN_SYSTEM_HEADER (decl)
3522 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3523 warning_with_decl (decl, "unused variable `%s'");
3526 /* Generate RTL code to terminate a binding contour.
3528 VARS is the chain of VAR_DECL nodes for the variables bound in this
3529 contour. There may actually be other nodes in this chain, but any
3530 nodes other than VAR_DECLS are ignored.
3532 MARK_ENDS is nonzero if we should put a note at the beginning
3533 and end of this binding contour.
3535 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3536 (That is true automatically if the contour has a saved stack level.) */
3539 expand_end_bindings (vars, mark_ends, dont_jump_in)
3544 register struct nesting *thisblock;
3547 while (block_stack->data.block.exception_region)
3549 /* Because we don't need or want a new temporary level and
3550 because we didn't create one in expand_eh_region_start,
3551 create a fake one now to avoid removing one in
3552 expand_end_bindings. */
3555 block_stack->data.block.exception_region = 0;
3557 expand_end_bindings (NULL_TREE, 0, 0);
3560 /* Since expand_eh_region_start does an expand_start_bindings, we
3561 have to first end all the bindings that were created by
3562 expand_eh_region_start. */
3564 thisblock = block_stack;
3566 /* If any of the variables in this scope were not used, warn the
3568 warn_about_unused_variables (vars);
3570 if (thisblock->exit_label)
3572 do_pending_stack_adjust ();
3573 emit_label (thisblock->exit_label);
3576 /* If necessary, make handlers for nonlocal gotos taking
3577 place in the function calls in this block. */
3578 if (function_call_count != thisblock->data.block.n_function_calls
3580 /* Make handler for outermost block
3581 if there were any nonlocal gotos to this function. */
3582 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3583 /* Make handler for inner block if it has something
3584 special to do when you jump out of it. */
3585 : (thisblock->data.block.cleanups != 0
3586 || thisblock->data.block.stack_level != 0)))
3587 expand_nl_goto_receivers (thisblock);
3589 /* Don't allow jumping into a block that has a stack level.
3590 Cleanups are allowed, though. */
3592 || thisblock->data.block.stack_level != 0)
3594 struct label_chain *chain;
3596 /* Any labels in this block are no longer valid to go to.
3597 Mark them to cause an error message. */
3598 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3600 DECL_TOO_LATE (chain->label) = 1;
3601 /* If any goto without a fixup came to this label,
3602 that must be an error, because gotos without fixups
3603 come from outside all saved stack-levels. */
3604 if (TREE_ADDRESSABLE (chain->label))
3605 error_with_decl (chain->label,
3606 "label `%s' used before containing binding contour");
3610 /* Restore stack level in effect before the block
3611 (only if variable-size objects allocated). */
3612 /* Perform any cleanups associated with the block. */
3614 if (thisblock->data.block.stack_level != 0
3615 || thisblock->data.block.cleanups != 0)
3617 /* Only clean up here if this point can actually be reached. */
3618 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3620 /* Don't let cleanups affect ({...}) constructs. */
3621 int old_expr_stmts_for_value = expr_stmts_for_value;
3622 rtx old_last_expr_value = last_expr_value;
3623 tree old_last_expr_type = last_expr_type;
3624 expr_stmts_for_value = 0;
3626 /* Do the cleanups. */
3627 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3629 do_pending_stack_adjust ();
3631 expr_stmts_for_value = old_expr_stmts_for_value;
3632 last_expr_value = old_last_expr_value;
3633 last_expr_type = old_last_expr_type;
3635 /* Restore the stack level. */
3637 if (reachable && thisblock->data.block.stack_level != 0)
3639 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3640 thisblock->data.block.stack_level, NULL_RTX);
3641 if (nonlocal_goto_handler_slots != 0)
3642 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3646 /* Any gotos out of this block must also do these things.
3647 Also report any gotos with fixups that came to labels in this
3649 fixup_gotos (thisblock,
3650 thisblock->data.block.stack_level,
3651 thisblock->data.block.cleanups,
3652 thisblock->data.block.first_insn,
3656 /* Mark the beginning and end of the scope if requested.
3657 We do this now, after running cleanups on the variables
3658 just going out of scope, so they are in scope for their cleanups. */
3661 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3663 /* Get rid of the beginning-mark if we don't make an end-mark. */
3664 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3666 /* If doing stupid register allocation, make sure lives of all
3667 register variables declared here extend thru end of scope. */
3670 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3671 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
3672 use_variable (DECL_RTL (decl));
3674 /* Restore the temporary level of TARGET_EXPRs. */
3675 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3677 /* Restore block_stack level for containing block. */
3679 stack_block_stack = thisblock->data.block.innermost_stack_block;
3680 POPSTACK (block_stack);
3682 /* Pop the stack slot nesting and free any slots at this level. */
3686 /* Generate RTL for the automatic variable declaration DECL.
3687 (Other kinds of declarations are simply ignored if seen here.) */
3693 struct nesting *thisblock;
3696 type = TREE_TYPE (decl);
3698 /* Only automatic variables need any expansion done.
3699 Static and external variables, and external functions,
3700 will be handled by `assemble_variable' (called from finish_decl).
3701 TYPE_DECL and CONST_DECL require nothing.
3702 PARM_DECLs are handled in `assign_parms'. */
3704 if (TREE_CODE (decl) != VAR_DECL)
3706 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3709 thisblock = block_stack;
3711 /* Create the RTL representation for the variable. */
3713 if (type == error_mark_node)
3714 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3715 else if (DECL_SIZE (decl) == 0)
3716 /* Variable with incomplete type. */
3718 if (DECL_INITIAL (decl) == 0)
3719 /* Error message was already done; now avoid a crash. */
3720 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3722 /* An initializer is going to decide the size of this array.
3723 Until we know the size, represent its address with a reg. */
3724 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3725 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3727 else if (DECL_MODE (decl) != BLKmode
3728 /* If -ffloat-store, don't put explicit float vars
3730 && !(flag_float_store
3731 && TREE_CODE (type) == REAL_TYPE)
3732 && ! TREE_THIS_VOLATILE (decl)
3733 && ! TREE_ADDRESSABLE (decl)
3734 && (DECL_REGISTER (decl) || ! obey_regdecls)
3735 /* if -fcheck-memory-usage, check all variables. */
3736 && ! current_function_check_memory_usage)
3738 /* Automatic variable that can go in a register. */
3739 int unsignedp = TREE_UNSIGNED (type);
3740 enum machine_mode reg_mode
3741 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3743 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3744 mark_user_reg (DECL_RTL (decl));
3746 if (POINTER_TYPE_P (type))
3747 mark_reg_pointer (DECL_RTL (decl),
3748 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3752 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3753 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3754 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3755 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3756 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3758 /* Variable of fixed size that goes on the stack. */
3762 /* If we previously made RTL for this decl, it must be an array
3763 whose size was determined by the initializer.
3764 The old address was a register; set that register now
3765 to the proper address. */
3766 if (DECL_RTL (decl) != 0)
3768 if (GET_CODE (DECL_RTL (decl)) != MEM
3769 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3771 oldaddr = XEXP (DECL_RTL (decl), 0);
3774 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3775 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3776 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3778 /* Set alignment we actually gave this decl. */
3779 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3780 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3784 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3785 if (addr != oldaddr)
3786 emit_move_insn (oldaddr, addr);
3789 /* If this is a memory ref that contains aggregate components,
3790 mark it as such for cse and loop optimize. */
3791 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3792 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3794 /* If this is in memory because of -ffloat-store,
3795 set the volatile bit, to prevent optimizations from
3796 undoing the effects. */
3797 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3798 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3801 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3804 /* Dynamic-size object: must push space on the stack. */
3808 /* Record the stack pointer on entry to block, if have
3809 not already done so. */
3810 if (thisblock->data.block.stack_level == 0)
3812 do_pending_stack_adjust ();
3813 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3814 &thisblock->data.block.stack_level,
3815 thisblock->data.block.first_insn);
3816 stack_block_stack = thisblock;
3819 /* Compute the variable's size, in bytes. */
3820 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3822 size_int (BITS_PER_UNIT)),
3823 NULL_RTX, VOIDmode, 0);
3826 /* Allocate space on the stack for the variable. Note that
3827 DECL_ALIGN says how the variable is to be aligned and we
3828 cannot use it to conclude anything about the alignment of
3830 address = allocate_dynamic_stack_space (size, NULL_RTX,
3831 TYPE_ALIGN (TREE_TYPE (decl)));
3833 /* Reference the variable indirect through that rtx. */
3834 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3836 /* If this is a memory ref that contains aggregate components,
3837 mark it as such for cse and loop optimize. */
3838 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3839 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3841 /* Indicate the alignment we actually gave this variable. */
3842 #ifdef STACK_BOUNDARY
3843 DECL_ALIGN (decl) = STACK_BOUNDARY;
3845 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3849 if (TREE_THIS_VOLATILE (decl))
3850 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3851 #if 0 /* A variable is not necessarily unchanging
3852 just because it is const. RTX_UNCHANGING_P
3853 means no change in the function,
3854 not merely no change in the variable's scope.
3855 It is correct to set RTX_UNCHANGING_P if the variable's scope
3856 is the whole function. There's no convenient way to test that. */
3857 if (TREE_READONLY (decl))
3858 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3861 /* If doing stupid register allocation, make sure life of any
3862 register variable starts here, at the start of its scope. */
3865 use_variable (DECL_RTL (decl));
3870 /* Emit code to perform the initialization of a declaration DECL. */
3873 expand_decl_init (decl)
3876 int was_used = TREE_USED (decl);
3878 /* If this is a CONST_DECL, we don't have to generate any code, but
3879 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3880 to be set while in the obstack containing the constant. If we don't
3881 do this, we can lose if we have functions nested three deep and the middle
3882 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3883 the innermost function is the first to expand that STRING_CST. */
3884 if (TREE_CODE (decl) == CONST_DECL)
3886 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3887 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3888 EXPAND_INITIALIZER);
3892 if (TREE_STATIC (decl))
3895 /* Compute and store the initial value now. */
3897 if (DECL_INITIAL (decl) == error_mark_node)
3899 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3901 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3902 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3903 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3907 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3909 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3910 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3914 /* Don't let the initialization count as "using" the variable. */
3915 TREE_USED (decl) = was_used;
3917 /* Free any temporaries we made while initializing the decl. */
3918 preserve_temp_slots (NULL_RTX);
3922 /* CLEANUP is an expression to be executed at exit from this binding contour;
3923 for example, in C++, it might call the destructor for this variable.
3925 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3926 CLEANUP multiple times, and have the correct semantics. This
3927 happens in exception handling, for gotos, returns, breaks that
3928 leave the current scope.
3930 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3931 that is not associated with any particular variable. */
3934 expand_decl_cleanup (decl, cleanup)
3937 struct nesting *thisblock;
3939 /* Error if we are not in any block. */
3940 if (current_function == 0 || block_stack == 0)
3943 thisblock = block_stack;
3945 /* Record the cleanup if there is one. */
3951 tree *cleanups = &thisblock->data.block.cleanups;
3952 int cond_context = conditional_context ();
3956 rtx flag = gen_reg_rtx (word_mode);
3961 emit_move_insn (flag, const0_rtx);
3962 set_flag_0 = get_insns ();
3965 thisblock->data.block.last_unconditional_cleanup
3966 = emit_insns_after (set_flag_0,
3967 thisblock->data.block.last_unconditional_cleanup);
3969 emit_move_insn (flag, const1_rtx);
3971 /* All cleanups must be on the function_obstack. */
3972 push_obstacks_nochange ();
3973 resume_temporary_allocation ();
3975 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3976 DECL_RTL (cond) = flag;
3978 /* Conditionalize the cleanup. */
3979 cleanup = build (COND_EXPR, void_type_node,
3980 truthvalue_conversion (cond),
3981 cleanup, integer_zero_node);
3982 cleanup = fold (cleanup);
3986 cleanups = thisblock->data.block.cleanup_ptr;
3989 /* All cleanups must be on the function_obstack. */
3990 push_obstacks_nochange ();
3991 resume_temporary_allocation ();
3992 cleanup = unsave_expr (cleanup);
3995 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
3998 /* If this block has a cleanup, it belongs in stack_block_stack. */
3999 stack_block_stack = thisblock;
4006 /* If this was optimized so that there is no exception region for the
4007 cleanup, then mark the TREE_LIST node, so that we can later tell
4008 if we need to call expand_eh_region_end. */
4009 if (! using_eh_for_cleanups_p
4010 || expand_eh_region_start_tree (decl, cleanup))
4011 TREE_ADDRESSABLE (t) = 1;
4012 /* If that started a new EH region, we're in a new block. */
4013 thisblock = block_stack;
4020 thisblock->data.block.last_unconditional_cleanup
4021 = emit_insns_after (seq,
4022 thisblock->data.block.last_unconditional_cleanup);
4026 thisblock->data.block.last_unconditional_cleanup
4028 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4034 /* Like expand_decl_cleanup, but suppress generating an exception handler
4035 to perform the cleanup. */
4038 expand_decl_cleanup_no_eh (decl, cleanup)
4041 int save_eh = using_eh_for_cleanups_p;
4044 using_eh_for_cleanups_p = 0;
4045 result = expand_decl_cleanup (decl, cleanup);
4046 using_eh_for_cleanups_p = save_eh;
4051 /* Arrange for the top element of the dynamic cleanup chain to be
4052 popped if we exit the current binding contour. DECL is the
4053 associated declaration, if any, otherwise NULL_TREE. If the
4054 current contour is left via an exception, then __sjthrow will pop
4055 the top element off the dynamic cleanup chain. The code that
4056 avoids doing the action we push into the cleanup chain in the
4057 exceptional case is contained in expand_cleanups.
4059 This routine is only used by expand_eh_region_start, and that is
4060 the only way in which an exception region should be started. This
4061 routine is only used when using the setjmp/longjmp codegen method
4062 for exception handling. */
4065 expand_dcc_cleanup (decl)
4068 struct nesting *thisblock;
4071 /* Error if we are not in any block. */
4072 if (current_function == 0 || block_stack == 0)
4074 thisblock = block_stack;
4076 /* Record the cleanup for the dynamic handler chain. */
4078 /* All cleanups must be on the function_obstack. */
4079 push_obstacks_nochange ();
4080 resume_temporary_allocation ();
4081 cleanup = make_node (POPDCC_EXPR);
4084 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4085 thisblock->data.block.cleanups
4086 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4088 /* If this block has a cleanup, it belongs in stack_block_stack. */
4089 stack_block_stack = thisblock;
4093 /* Arrange for the top element of the dynamic handler chain to be
4094 popped if we exit the current binding contour. DECL is the
4095 associated declaration, if any, otherwise NULL_TREE. If the current
4096 contour is left via an exception, then __sjthrow will pop the top
4097 element off the dynamic handler chain. The code that avoids doing
4098 the action we push into the handler chain in the exceptional case
4099 is contained in expand_cleanups.
4101 This routine is only used by expand_eh_region_start, and that is
4102 the only way in which an exception region should be started. This
4103 routine is only used when using the setjmp/longjmp codegen method
4104 for exception handling. */
4107 expand_dhc_cleanup (decl)
4110 struct nesting *thisblock;
4113 /* Error if we are not in any block. */
4114 if (current_function == 0 || block_stack == 0)
4116 thisblock = block_stack;
4118 /* Record the cleanup for the dynamic handler chain. */
4120 /* All cleanups must be on the function_obstack. */
4121 push_obstacks_nochange ();
4122 resume_temporary_allocation ();
4123 cleanup = make_node (POPDHC_EXPR);
4126 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4127 thisblock->data.block.cleanups
4128 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4130 /* If this block has a cleanup, it belongs in stack_block_stack. */
4131 stack_block_stack = thisblock;
4135 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4136 DECL_ELTS is the list of elements that belong to DECL's type.
4137 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4140 expand_anon_union_decl (decl, cleanup, decl_elts)
4141 tree decl, cleanup, decl_elts;
4143 struct nesting *thisblock = current_function == 0 ? 0 : block_stack;
4147 expand_decl_cleanup (decl, cleanup);
4148 x = DECL_RTL (decl);
4152 tree decl_elt = TREE_VALUE (decl_elts);
4153 tree cleanup_elt = TREE_PURPOSE (decl_elts);
4154 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4156 /* Propagate the union's alignment to the elements. */
4157 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4159 /* If the element has BLKmode and the union doesn't, the union is
4160 aligned such that the element doesn't need to have BLKmode, so
4161 change the element's mode to the appropriate one for its size. */
4162 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4163 DECL_MODE (decl_elt) = mode
4164 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4167 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4168 instead create a new MEM rtx with the proper mode. */
4169 if (GET_CODE (x) == MEM)
4171 if (mode == GET_MODE (x))
4172 DECL_RTL (decl_elt) = x;
4175 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4176 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4177 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4180 else if (GET_CODE (x) == REG)
4182 if (mode == GET_MODE (x))
4183 DECL_RTL (decl_elt) = x;
4185 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4190 /* Record the cleanup if there is one. */
4193 thisblock->data.block.cleanups
4194 = temp_tree_cons (decl_elt, cleanup_elt,
4195 thisblock->data.block.cleanups);
4197 decl_elts = TREE_CHAIN (decl_elts);
4201 /* Expand a list of cleanups LIST.
4202 Elements may be expressions or may be nested lists.
4204 If DONT_DO is nonnull, then any list-element
4205 whose TREE_PURPOSE matches DONT_DO is omitted.
4206 This is sometimes used to avoid a cleanup associated with
4207 a value that is being returned out of the scope.
4209 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4210 goto and handle protection regions specially in that case.
4212 If REACHABLE, we emit code, otherwise just inform the exception handling
4213 code about this finalization. */
4216 expand_cleanups (list, dont_do, in_fixup, reachable)
4223 for (tail = list; tail; tail = TREE_CHAIN (tail))
4224 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4226 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4227 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4232 tree cleanup = TREE_VALUE (tail);
4234 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4235 if (TREE_CODE (cleanup) != POPDHC_EXPR
4236 && TREE_CODE (cleanup) != POPDCC_EXPR
4237 /* See expand_eh_region_start_tree for this case. */
4238 && ! TREE_ADDRESSABLE (tail))
4240 cleanup = protect_with_terminate (cleanup);
4241 expand_eh_region_end (cleanup);
4247 /* Cleanups may be run multiple times. For example,
4248 when exiting a binding contour, we expand the
4249 cleanups associated with that contour. When a goto
4250 within that binding contour has a target outside that
4251 contour, it will expand all cleanups from its scope to
4252 the target. Though the cleanups are expanded multiple
4253 times, the control paths are non-overlapping so the
4254 cleanups will not be executed twice. */
4256 /* We may need to protect fixups with rethrow regions. */
4257 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4260 expand_fixup_region_start ();
4262 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4264 expand_fixup_region_end (TREE_VALUE (tail));
4271 /* Mark when the context we are emitting RTL for as a conditional
4272 context, so that any cleanup actions we register with
4273 expand_decl_init will be properly conditionalized when those
4274 cleanup actions are later performed. Must be called before any
4275 expression (tree) is expanded that is within a conditional context. */
4278 start_cleanup_deferral ()
4280 /* block_stack can be NULL if we are inside the parameter list. It is
4281 OK to do nothing, because cleanups aren't possible here. */
4283 ++block_stack->data.block.conditional_code;
4286 /* Mark the end of a conditional region of code. Because cleanup
4287 deferrals may be nested, we may still be in a conditional region
4288 after we end the currently deferred cleanups, only after we end all
4289 deferred cleanups, are we back in unconditional code. */
4292 end_cleanup_deferral ()
4294 /* block_stack can be NULL if we are inside the parameter list. It is
4295 OK to do nothing, because cleanups aren't possible here. */
4297 --block_stack->data.block.conditional_code;
4300 /* Move all cleanups from the current block_stack
4301 to the containing block_stack, where they are assumed to
4302 have been created. If anything can cause a temporary to
4303 be created, but not expanded for more than one level of
4304 block_stacks, then this code will have to change. */
4309 struct nesting *block = block_stack;
4310 struct nesting *outer = block->next;
4312 outer->data.block.cleanups
4313 = chainon (block->data.block.cleanups,
4314 outer->data.block.cleanups);
4315 block->data.block.cleanups = 0;
4319 last_cleanup_this_contour ()
4321 if (block_stack == 0)
4324 return block_stack->data.block.cleanups;
4327 /* Return 1 if there are any pending cleanups at this point.
4328 If THIS_CONTOUR is nonzero, check the current contour as well.
4329 Otherwise, look only at the contours that enclose this one. */
4332 any_pending_cleanups (this_contour)
4335 struct nesting *block;
4337 if (current_function == NULL || current_function->stmt == NULL
4338 || block_stack == 0)
4341 if (this_contour && block_stack->data.block.cleanups != NULL)
4343 if (block_stack->data.block.cleanups == 0
4344 && block_stack->data.block.outer_cleanups == 0)
4347 for (block = block_stack->next; block; block = block->next)
4348 if (block->data.block.cleanups != 0)
4354 /* Enter a case (Pascal) or switch (C) statement.
4355 Push a block onto case_stack and nesting_stack
4356 to accumulate the case-labels that are seen
4357 and to record the labels generated for the statement.
4359 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4360 Otherwise, this construct is transparent for `exit_something'.
4362 EXPR is the index-expression to be dispatched on.
4363 TYPE is its nominal type. We could simply convert EXPR to this type,
4364 but instead we take short cuts. */
4367 expand_start_case (exit_flag, expr, type, printname)
4371 const char *printname;
4373 register struct nesting *thiscase = ALLOC_NESTING ();
4375 /* Make an entry on case_stack for the case we are entering. */
4377 thiscase->next = case_stack;
4378 thiscase->all = nesting_stack;
4379 thiscase->depth = ++nesting_depth;
4380 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4381 thiscase->data.case_stmt.case_list = 0;
4382 thiscase->data.case_stmt.index_expr = expr;
4383 thiscase->data.case_stmt.nominal_type = type;
4384 thiscase->data.case_stmt.default_label = 0;
4385 thiscase->data.case_stmt.num_ranges = 0;
4386 thiscase->data.case_stmt.printname = printname;
4387 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4388 case_stack = thiscase;
4389 nesting_stack = thiscase;
4391 do_pending_stack_adjust ();
4393 /* Make sure case_stmt.start points to something that won't
4394 need any transformation before expand_end_case. */
4395 if (GET_CODE (get_last_insn ()) != NOTE)
4396 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4398 thiscase->data.case_stmt.start = get_last_insn ();
4400 start_cleanup_deferral ();
4404 /* Start a "dummy case statement" within which case labels are invalid
4405 and are not connected to any larger real case statement.
4406 This can be used if you don't want to let a case statement jump
4407 into the middle of certain kinds of constructs. */
4410 expand_start_case_dummy ()
4412 register struct nesting *thiscase = ALLOC_NESTING ();
4414 /* Make an entry on case_stack for the dummy. */
4416 thiscase->next = case_stack;
4417 thiscase->all = nesting_stack;
4418 thiscase->depth = ++nesting_depth;
4419 thiscase->exit_label = 0;
4420 thiscase->data.case_stmt.case_list = 0;
4421 thiscase->data.case_stmt.start = 0;
4422 thiscase->data.case_stmt.nominal_type = 0;
4423 thiscase->data.case_stmt.default_label = 0;
4424 thiscase->data.case_stmt.num_ranges = 0;
4425 case_stack = thiscase;
4426 nesting_stack = thiscase;
4427 start_cleanup_deferral ();
4430 /* End a dummy case statement. */
4433 expand_end_case_dummy ()
4435 end_cleanup_deferral ();
4436 POPSTACK (case_stack);
4439 /* Return the data type of the index-expression
4440 of the innermost case statement, or null if none. */
4443 case_index_expr_type ()
4446 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4453 /* If this is the first label, warn if any insns have been emitted. */
4454 if (case_stack->data.case_stmt.line_number_status >= 0)
4458 restore_line_number_status
4459 (case_stack->data.case_stmt.line_number_status);
4460 case_stack->data.case_stmt.line_number_status = -1;
4462 for (insn = case_stack->data.case_stmt.start;
4464 insn = NEXT_INSN (insn))
4466 if (GET_CODE (insn) == CODE_LABEL)
4468 if (GET_CODE (insn) != NOTE
4469 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4472 insn = PREV_INSN (insn);
4473 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4475 /* If insn is zero, then there must have been a syntax error. */
4477 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4478 NOTE_LINE_NUMBER(insn),
4479 "unreachable code at beginning of %s",
4480 case_stack->data.case_stmt.printname);
4487 /* Accumulate one case or default label inside a case or switch statement.
4488 VALUE is the value of the case (a null pointer, for a default label).
4489 The function CONVERTER, when applied to arguments T and V,
4490 converts the value V to the type T.
4492 If not currently inside a case or switch statement, return 1 and do
4493 nothing. The caller will print a language-specific error message.
4494 If VALUE is a duplicate or overlaps, return 2 and do nothing
4495 except store the (first) duplicate node in *DUPLICATE.
4496 If VALUE is out of range, return 3 and do nothing.
4497 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4498 Return 0 on success.
4500 Extended to handle range statements. */
4503 pushcase (value, converter, label, duplicate)
4504 register tree value;
4505 tree (*converter) PROTO((tree, tree));
4506 register tree label;
4512 /* Fail if not inside a real case statement. */
4513 if (! (case_stack && case_stack->data.case_stmt.start))
4516 if (stack_block_stack
4517 && stack_block_stack->depth > case_stack->depth)
4520 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4521 nominal_type = case_stack->data.case_stmt.nominal_type;
4523 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4524 if (index_type == error_mark_node)
4527 /* Convert VALUE to the type in which the comparisons are nominally done. */
4529 value = (*converter) (nominal_type, value);
4533 /* Fail if this value is out of range for the actual type of the index
4534 (which may be narrower than NOMINAL_TYPE). */
4535 if (value != 0 && ! int_fits_type_p (value, index_type))
4538 /* Fail if this is a duplicate or overlaps another entry. */
4541 if (case_stack->data.case_stmt.default_label != 0)
4543 *duplicate = case_stack->data.case_stmt.default_label;
4546 case_stack->data.case_stmt.default_label = label;
4549 return add_case_node (value, value, label, duplicate);
4551 expand_label (label);
4555 /* Like pushcase but this case applies to all values between VALUE1 and
4556 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4557 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4558 starts at VALUE1 and ends at the highest value of the index type.
4559 If both are NULL, this case applies to all values.
4561 The return value is the same as that of pushcase but there is one
4562 additional error code: 4 means the specified range was empty. */
4565 pushcase_range (value1, value2, converter, label, duplicate)
4566 register tree value1, value2;
4567 tree (*converter) PROTO((tree, tree));
4568 register tree label;
4574 /* Fail if not inside a real case statement. */
4575 if (! (case_stack && case_stack->data.case_stmt.start))
4578 if (stack_block_stack
4579 && stack_block_stack->depth > case_stack->depth)
4582 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4583 nominal_type = case_stack->data.case_stmt.nominal_type;
4585 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4586 if (index_type == error_mark_node)
4591 /* Convert VALUEs to type in which the comparisons are nominally done
4592 and replace any unspecified value with the corresponding bound. */
4594 value1 = TYPE_MIN_VALUE (index_type);
4596 value2 = TYPE_MAX_VALUE (index_type);
4598 /* Fail if the range is empty. Do this before any conversion since
4599 we want to allow out-of-range empty ranges. */
4600 if (value2 && tree_int_cst_lt (value2, value1))
4603 value1 = (*converter) (nominal_type, value1);
4605 /* If the max was unbounded, use the max of the nominal_type we are
4606 converting to. Do this after the < check above to suppress false
4609 value2 = TYPE_MAX_VALUE (nominal_type);
4610 value2 = (*converter) (nominal_type, value2);
4612 /* Fail if these values are out of range. */
4613 if (TREE_CONSTANT_OVERFLOW (value1)
4614 || ! int_fits_type_p (value1, index_type))
4617 if (TREE_CONSTANT_OVERFLOW (value2)
4618 || ! int_fits_type_p (value2, index_type))
4621 return add_case_node (value1, value2, label, duplicate);
4624 /* Do the actual insertion of a case label for pushcase and pushcase_range
4625 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4626 slowdown for large switch statements. */
4629 add_case_node (low, high, label, duplicate)
4634 struct case_node *p, **q, *r;
4636 q = &case_stack->data.case_stmt.case_list;
4643 /* Keep going past elements distinctly greater than HIGH. */
4644 if (tree_int_cst_lt (high, p->low))
4647 /* or distinctly less than LOW. */
4648 else if (tree_int_cst_lt (p->high, low))
4653 /* We have an overlap; this is an error. */
4654 *duplicate = p->code_label;
4659 /* Add this label to the chain, and succeed.
4660 Copy LOW, HIGH so they are on temporary rather than momentary
4661 obstack and will thus survive till the end of the case statement. */
4663 r = (struct case_node *) oballoc (sizeof (struct case_node));
4664 r->low = copy_node (low);
4666 /* If the bounds are equal, turn this into the one-value case. */
4668 if (tree_int_cst_equal (low, high))
4672 r->high = copy_node (high);
4673 case_stack->data.case_stmt.num_ranges++;
4676 r->code_label = label;
4677 expand_label (label);
4687 struct case_node *s;
4693 if (! (b = p->balance))
4694 /* Growth propagation from left side. */
4701 if ((p->left = s = r->right))
4710 if ((r->parent = s))
4718 case_stack->data.case_stmt.case_list = r;
4721 /* r->balance == +1 */
4726 struct case_node *t = r->right;
4728 if ((p->left = s = t->right))
4732 if ((r->right = s = t->left))
4746 if ((t->parent = s))
4754 case_stack->data.case_stmt.case_list = t;
4761 /* p->balance == +1; growth of left side balances the node. */
4771 if (! (b = p->balance))
4772 /* Growth propagation from right side. */
4780 if ((p->right = s = r->left))
4788 if ((r->parent = s))
4797 case_stack->data.case_stmt.case_list = r;
4801 /* r->balance == -1 */
4805 struct case_node *t = r->left;
4807 if ((p->right = s = t->left))
4812 if ((r->left = s = t->right))
4826 if ((t->parent = s))
4835 case_stack->data.case_stmt.case_list = t;
4841 /* p->balance == -1; growth of right side balances the node. */
4855 /* Returns the number of possible values of TYPE.
4856 Returns -1 if the number is unknown or variable.
4857 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4858 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4859 do not increase monotonically (there may be duplicates);
4860 to 1 if the values increase monotonically, but not always by 1;
4861 otherwise sets it to 0. */
4864 all_cases_count (type, spareness)
4868 HOST_WIDE_INT count;
4871 switch (TREE_CODE (type))
4878 count = 1 << BITS_PER_UNIT;
4882 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4883 || TYPE_MAX_VALUE (type) == NULL
4884 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4889 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4890 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4891 but with overflow checking. */
4892 tree mint = TYPE_MIN_VALUE (type);
4893 tree maxt = TYPE_MAX_VALUE (type);
4894 HOST_WIDE_INT lo, hi;
4895 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4897 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4899 add_double (lo, hi, 1, 0, &lo, &hi);
4900 if (hi != 0 || lo < 0)
4907 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4909 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4910 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4911 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4912 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4916 if (*spareness == 1)
4918 tree prev = TREE_VALUE (TYPE_VALUES (type));
4919 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4921 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4926 prev = TREE_VALUE (t);
4935 #define BITARRAY_TEST(ARRAY, INDEX) \
4936 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4937 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4938 #define BITARRAY_SET(ARRAY, INDEX) \
4939 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4940 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4942 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4943 with the case values we have seen, assuming the case expression
4945 SPARSENESS is as determined by all_cases_count.
4947 The time needed is proportional to COUNT, unless
4948 SPARSENESS is 2, in which case quadratic time is needed. */
4951 mark_seen_cases (type, cases_seen, count, sparseness)
4953 unsigned char *cases_seen;
4957 tree next_node_to_try = NULL_TREE;
4958 long next_node_offset = 0;
4960 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4961 tree val = make_node (INTEGER_CST);
4962 TREE_TYPE (val) = type;
4965 else if (sparseness == 2)
4970 /* This less efficient loop is only needed to handle
4971 duplicate case values (multiple enum constants
4972 with the same value). */
4973 TREE_TYPE (val) = TREE_TYPE (root->low);
4974 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4975 t = TREE_CHAIN (t), xlo++)
4977 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4978 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4982 /* Keep going past elements distinctly greater than VAL. */
4983 if (tree_int_cst_lt (val, n->low))
4986 /* or distinctly less than VAL. */
4987 else if (tree_int_cst_lt (n->high, val))
4992 /* We have found a matching range. */
4993 BITARRAY_SET (cases_seen, xlo);
5003 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5004 for (n = root; n; n = n->right)
5006 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5007 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5008 while ( ! tree_int_cst_lt (n->high, val))
5010 /* Calculate (into xlo) the "offset" of the integer (val).
5011 The element with lowest value has offset 0, the next smallest
5012 element has offset 1, etc. */
5014 HOST_WIDE_INT xlo, xhi;
5016 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5018 /* The TYPE_VALUES will be in increasing order, so
5019 starting searching where we last ended. */
5020 t = next_node_to_try;
5021 xlo = next_node_offset;
5027 t = TYPE_VALUES (type);
5030 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5032 next_node_to_try = TREE_CHAIN (t);
5033 next_node_offset = xlo + 1;
5038 if (t == next_node_to_try)
5047 t = TYPE_MIN_VALUE (type);
5049 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5053 add_double (xlo, xhi,
5054 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5058 if (xhi == 0 && xlo >= 0 && xlo < count)
5059 BITARRAY_SET (cases_seen, xlo);
5060 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5062 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5068 /* Called when the index of a switch statement is an enumerated type
5069 and there is no default label.
5071 Checks that all enumeration literals are covered by the case
5072 expressions of a switch. Also, warn if there are any extra
5073 switch cases that are *not* elements of the enumerated type.
5075 If all enumeration literals were covered by the case expressions,
5076 turn one of the expressions into the default expression since it should
5077 not be possible to fall through such a switch. */
5080 check_for_full_enumeration_handling (type)
5083 register struct case_node *n;
5084 register tree chain;
5085 #if 0 /* variable used by 'if 0'ed code below. */
5086 register struct case_node **l;
5090 /* True iff the selector type is a numbered set mode. */
5093 /* The number of possible selector values. */
5096 /* For each possible selector value. a one iff it has been matched
5097 by a case value alternative. */
5098 unsigned char *cases_seen;
5100 /* The allocated size of cases_seen, in chars. */
5106 size = all_cases_count (type, &sparseness);
5107 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5109 if (size > 0 && size < 600000
5110 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5111 this optimization if we don't have enough memory rather than
5112 aborting, as xmalloc would do. */
5113 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5116 tree v = TYPE_VALUES (type);
5118 /* The time complexity of this code is normally O(N), where
5119 N being the number of members in the enumerated type.
5120 However, if type is a ENUMERAL_TYPE whose values do not
5121 increase monotonically, O(N*log(N)) time may be needed. */
5123 mark_seen_cases (type, cases_seen, size, sparseness);
5125 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5127 if (BITARRAY_TEST(cases_seen, i) == 0)
5128 warning ("enumeration value `%s' not handled in switch",
5129 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5135 /* Now we go the other way around; we warn if there are case
5136 expressions that don't correspond to enumerators. This can
5137 occur since C and C++ don't enforce type-checking of
5138 assignments to enumeration variables. */
5140 if (case_stack->data.case_stmt.case_list
5141 && case_stack->data.case_stmt.case_list->left)
5142 case_stack->data.case_stmt.case_list
5143 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5145 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5147 for (chain = TYPE_VALUES (type);
5148 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5149 chain = TREE_CHAIN (chain))
5154 if (TYPE_NAME (type) == 0)
5155 warning ("case value `%ld' not in enumerated type",
5156 (long) TREE_INT_CST_LOW (n->low));
5158 warning ("case value `%ld' not in enumerated type `%s'",
5159 (long) TREE_INT_CST_LOW (n->low),
5160 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5163 : DECL_NAME (TYPE_NAME (type))));
5165 if (!tree_int_cst_equal (n->low, n->high))
5167 for (chain = TYPE_VALUES (type);
5168 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5169 chain = TREE_CHAIN (chain))
5174 if (TYPE_NAME (type) == 0)
5175 warning ("case value `%ld' not in enumerated type",
5176 (long) TREE_INT_CST_LOW (n->high));
5178 warning ("case value `%ld' not in enumerated type `%s'",
5179 (long) TREE_INT_CST_LOW (n->high),
5180 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5183 : DECL_NAME (TYPE_NAME (type))));
5189 /* ??? This optimization is disabled because it causes valid programs to
5190 fail. ANSI C does not guarantee that an expression with enum type
5191 will have a value that is the same as one of the enumeration literals. */
5193 /* If all values were found as case labels, make one of them the default
5194 label. Thus, this switch will never fall through. We arbitrarily pick
5195 the last one to make the default since this is likely the most
5196 efficient choice. */
5200 for (l = &case_stack->data.case_stmt.case_list;
5205 case_stack->data.case_stmt.default_label = (*l)->code_label;
5212 /* Terminate a case (Pascal) or switch (C) statement
5213 in which ORIG_INDEX is the expression to be tested.
5214 Generate the code to test it and jump to the right place. */
5217 expand_end_case (orig_index)
5220 tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval;
5221 rtx default_label = 0;
5222 register struct case_node *n;
5230 register struct nesting *thiscase = case_stack;
5231 tree index_expr, index_type;
5234 /* Don't crash due to previous errors. */
5235 if (thiscase == NULL)
5238 table_label = gen_label_rtx ();
5239 index_expr = thiscase->data.case_stmt.index_expr;
5240 index_type = TREE_TYPE (index_expr);
5241 unsignedp = TREE_UNSIGNED (index_type);
5243 do_pending_stack_adjust ();
5245 /* This might get an spurious warning in the presence of a syntax error;
5246 it could be fixed by moving the call to check_seenlabel after the
5247 check for error_mark_node, and copying the code of check_seenlabel that
5248 deals with case_stack->data.case_stmt.line_number_status /
5249 restore_line_number_status in front of the call to end_cleanup_deferral;
5250 However, this might miss some useful warnings in the presence of
5251 non-syntax errors. */
5254 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5255 if (index_type != error_mark_node)
5257 /* If switch expression was an enumerated type, check that all
5258 enumeration literals are covered by the cases.
5259 No sense trying this if there's a default case, however. */
5261 if (!thiscase->data.case_stmt.default_label
5262 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5263 && TREE_CODE (index_expr) != INTEGER_CST)
5264 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5266 /* If we don't have a default-label, create one here,
5267 after the body of the switch. */
5268 if (thiscase->data.case_stmt.default_label == 0)
5270 thiscase->data.case_stmt.default_label
5271 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5272 expand_label (thiscase->data.case_stmt.default_label);
5274 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5276 before_case = get_last_insn ();
5278 if (thiscase->data.case_stmt.case_list
5279 && thiscase->data.case_stmt.case_list->left)
5280 thiscase->data.case_stmt.case_list
5281 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5283 /* Simplify the case-list before we count it. */
5284 group_case_nodes (thiscase->data.case_stmt.case_list);
5286 /* Get upper and lower bounds of case values.
5287 Also convert all the case values to the index expr's data type. */
5290 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5292 /* Check low and high label values are integers. */
5293 if (TREE_CODE (n->low) != INTEGER_CST)
5295 if (TREE_CODE (n->high) != INTEGER_CST)
5298 n->low = convert (index_type, n->low);
5299 n->high = convert (index_type, n->high);
5301 /* Count the elements and track the largest and smallest
5302 of them (treating them as signed even if they are not). */
5310 if (INT_CST_LT (n->low, minval))
5312 if (INT_CST_LT (maxval, n->high))
5315 /* A range counts double, since it requires two compares. */
5316 if (! tree_int_cst_equal (n->low, n->high))
5320 orig_minval = minval;
5322 /* Compute span of values. */
5324 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5326 end_cleanup_deferral ();
5330 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5332 emit_jump (default_label);
5335 /* If range of values is much bigger than number of values,
5336 make a sequence of conditional branches instead of a dispatch.
5337 If the switch-index is a constant, do it this way
5338 because we can optimize it. */
5340 #ifndef CASE_VALUES_THRESHOLD
5342 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5344 /* If machine does not have a case insn that compares the
5345 bounds, this means extra overhead for dispatch tables
5346 which raises the threshold for using them. */
5347 #define CASE_VALUES_THRESHOLD 5
5348 #endif /* HAVE_casesi */
5349 #endif /* CASE_VALUES_THRESHOLD */
5351 else if (TREE_INT_CST_HIGH (range) != 0
5352 || count < (unsigned int) CASE_VALUES_THRESHOLD
5353 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5355 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5358 || TREE_CODE (index_expr) == INTEGER_CST
5359 /* These will reduce to a constant. */
5360 || (TREE_CODE (index_expr) == CALL_EXPR
5361 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5362 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5363 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5364 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5365 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5367 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5369 /* If the index is a short or char that we do not have
5370 an insn to handle comparisons directly, convert it to
5371 a full integer now, rather than letting each comparison
5372 generate the conversion. */
5374 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5375 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5376 == CODE_FOR_nothing))
5378 enum machine_mode wider_mode;
5379 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5380 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5381 if (cmp_optab->handlers[(int) wider_mode].insn_code
5382 != CODE_FOR_nothing)
5384 index = convert_to_mode (wider_mode, index, unsignedp);
5390 do_pending_stack_adjust ();
5392 index = protect_from_queue (index, 0);
5393 if (GET_CODE (index) == MEM)
5394 index = copy_to_reg (index);
5395 if (GET_CODE (index) == CONST_INT
5396 || TREE_CODE (index_expr) == INTEGER_CST)
5398 /* Make a tree node with the proper constant value
5399 if we don't already have one. */
5400 if (TREE_CODE (index_expr) != INTEGER_CST)
5403 = build_int_2 (INTVAL (index),
5404 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5405 index_expr = convert (index_type, index_expr);
5408 /* For constant index expressions we need only
5409 issue a unconditional branch to the appropriate
5410 target code. The job of removing any unreachable
5411 code is left to the optimisation phase if the
5412 "-O" option is specified. */
5413 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5414 if (! tree_int_cst_lt (index_expr, n->low)
5415 && ! tree_int_cst_lt (n->high, index_expr))
5419 emit_jump (label_rtx (n->code_label));
5421 emit_jump (default_label);
5425 /* If the index expression is not constant we generate
5426 a binary decision tree to select the appropriate
5427 target code. This is done as follows:
5429 The list of cases is rearranged into a binary tree,
5430 nearly optimal assuming equal probability for each case.
5432 The tree is transformed into RTL, eliminating
5433 redundant test conditions at the same time.
5435 If program flow could reach the end of the
5436 decision tree an unconditional jump to the
5437 default code is emitted. */
5440 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5441 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5442 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5444 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5445 default_label, index_type);
5446 emit_jump_if_reachable (default_label);
5455 enum machine_mode index_mode = SImode;
5456 int index_bits = GET_MODE_BITSIZE (index_mode);
5458 enum machine_mode op_mode;
5460 /* Convert the index to SImode. */
5461 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5462 > GET_MODE_BITSIZE (index_mode))
5464 enum machine_mode omode = TYPE_MODE (index_type);
5465 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5467 /* We must handle the endpoints in the original mode. */
5468 index_expr = build (MINUS_EXPR, index_type,
5469 index_expr, minval);
5470 minval = integer_zero_node;
5471 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5472 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5473 omode, 1, 0, default_label);
5474 /* Now we can safely truncate. */
5475 index = convert_to_mode (index_mode, index, 0);
5479 if (TYPE_MODE (index_type) != index_mode)
5481 index_expr = convert (type_for_size (index_bits, 0),
5483 index_type = TREE_TYPE (index_expr);
5486 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5489 index = protect_from_queue (index, 0);
5490 do_pending_stack_adjust ();
5492 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5493 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5495 index = copy_to_mode_reg (op_mode, index);
5497 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5499 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5500 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5502 op1 = copy_to_mode_reg (op_mode, op1);
5504 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5506 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5507 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5509 op2 = copy_to_mode_reg (op_mode, op2);
5511 emit_jump_insn (gen_casesi (index, op1, op2,
5512 table_label, default_label));
5516 #ifdef HAVE_tablejump
5517 if (! win && HAVE_tablejump)
5519 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5520 fold (build (MINUS_EXPR, index_type,
5521 index_expr, minval)));
5522 index_type = TREE_TYPE (index_expr);
5523 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5525 index = protect_from_queue (index, 0);
5526 do_pending_stack_adjust ();
5528 do_tablejump (index, TYPE_MODE (index_type),
5529 expand_expr (range, NULL_RTX, VOIDmode, 0),
5530 table_label, default_label);
5537 /* Get table of labels to jump to, in order of case index. */
5539 ncases = TREE_INT_CST_LOW (range) + 1;
5540 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5541 bzero ((char *) labelvec, ncases * sizeof (rtx));
5543 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5545 register HOST_WIDE_INT i
5546 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5551 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5552 if (i + TREE_INT_CST_LOW (orig_minval)
5553 == TREE_INT_CST_LOW (n->high))
5559 /* Fill in the gaps with the default. */
5560 for (i = 0; i < ncases; i++)
5561 if (labelvec[i] == 0)
5562 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5564 /* Output the table */
5565 emit_label (table_label);
5567 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5568 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5569 gen_rtx_LABEL_REF (Pmode, table_label),
5570 gen_rtvec_v (ncases, labelvec),
5571 const0_rtx, const0_rtx));
5573 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5574 gen_rtvec_v (ncases, labelvec)));
5576 /* If the case insn drops through the table,
5577 after the table we must jump to the default-label.
5578 Otherwise record no drop-through after the table. */
5579 #ifdef CASE_DROPS_THROUGH
5580 emit_jump (default_label);
5586 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5587 reorder_insns (before_case, get_last_insn (),
5588 thiscase->data.case_stmt.start);
5591 end_cleanup_deferral ();
5593 if (thiscase->exit_label)
5594 emit_label (thiscase->exit_label);
5596 POPSTACK (case_stack);
5601 /* Convert the tree NODE into a list linked by the right field, with the left
5602 field zeroed. RIGHT is used for recursion; it is a list to be placed
5603 rightmost in the resulting list. */
5605 static struct case_node *
5606 case_tree2list (node, right)
5607 struct case_node *node, *right;
5609 struct case_node *left;
5612 right = case_tree2list (node->right, right);
5614 node->right = right;
5615 if ((left = node->left))
5618 return case_tree2list (left, node);
5624 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5627 do_jump_if_equal (op1, op2, label, unsignedp)
5628 rtx op1, op2, label;
5631 if (GET_CODE (op1) == CONST_INT
5632 && GET_CODE (op2) == CONST_INT)
5634 if (INTVAL (op1) == INTVAL (op2))
5639 enum machine_mode mode = GET_MODE (op1);
5640 if (mode == VOIDmode)
5641 mode = GET_MODE (op2);
5642 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5647 /* Not all case values are encountered equally. This function
5648 uses a heuristic to weight case labels, in cases where that
5649 looks like a reasonable thing to do.
5651 Right now, all we try to guess is text, and we establish the
5654 chars above space: 16
5663 If we find any cases in the switch that are not either -1 or in the range
5664 of valid ASCII characters, or are control characters other than those
5665 commonly used with "\", don't treat this switch scanning text.
5667 Return 1 if these nodes are suitable for cost estimation, otherwise
5671 estimate_case_costs (node)
5674 tree min_ascii = build_int_2 (-1, -1);
5675 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5679 /* If we haven't already made the cost table, make it now. Note that the
5680 lower bound of the table is -1, not zero. */
5682 if (cost_table == NULL)
5684 cost_table = ((short *) xcalloc (129, sizeof (short))) + 1;
5686 for (i = 0; i < 128; i++)
5690 else if (ISPUNCT (i))
5692 else if (ISCNTRL (i))
5696 cost_table[' '] = 8;
5697 cost_table['\t'] = 4;
5698 cost_table['\0'] = 4;
5699 cost_table['\n'] = 2;
5700 cost_table['\f'] = 1;
5701 cost_table['\v'] = 1;
5702 cost_table['\b'] = 1;
5705 /* See if all the case expressions look like text. It is text if the
5706 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5707 as signed arithmetic since we don't want to ever access cost_table with a
5708 value less than -1. Also check that none of the constants in a range
5709 are strange control characters. */
5711 for (n = node; n; n = n->right)
5713 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5716 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5717 if (cost_table[i] < 0)
5721 /* All interesting values are within the range of interesting
5722 ASCII characters. */
5726 /* Scan an ordered list of case nodes
5727 combining those with consecutive values or ranges.
5729 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5732 group_case_nodes (head)
5735 case_node_ptr node = head;
5739 rtx lb = next_real_insn (label_rtx (node->code_label));
5741 case_node_ptr np = node;
5743 /* Try to group the successors of NODE with NODE. */
5744 while (((np = np->right) != 0)
5745 /* Do they jump to the same place? */
5746 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5747 || (lb != 0 && lb2 != 0
5748 && simplejump_p (lb)
5749 && simplejump_p (lb2)
5750 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5751 SET_SRC (PATTERN (lb2)))))
5752 /* Are their ranges consecutive? */
5753 && tree_int_cst_equal (np->low,
5754 fold (build (PLUS_EXPR,
5755 TREE_TYPE (node->high),
5758 /* An overflow is not consecutive. */
5759 && tree_int_cst_lt (node->high,
5760 fold (build (PLUS_EXPR,
5761 TREE_TYPE (node->high),
5763 integer_one_node))))
5765 node->high = np->high;
5767 /* NP is the first node after NODE which can't be grouped with it.
5768 Delete the nodes in between, and move on to that node. */
5774 /* Take an ordered list of case nodes
5775 and transform them into a near optimal binary tree,
5776 on the assumption that any target code selection value is as
5777 likely as any other.
5779 The transformation is performed by splitting the ordered
5780 list into two equal sections plus a pivot. The parts are
5781 then attached to the pivot as left and right branches. Each
5782 branch is then transformed recursively. */
5785 balance_case_nodes (head, parent)
5786 case_node_ptr *head;
5787 case_node_ptr parent;
5789 register case_node_ptr np;
5797 register case_node_ptr *npp;
5800 /* Count the number of entries on branch. Also count the ranges. */
5804 if (!tree_int_cst_equal (np->low, np->high))
5808 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5812 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5820 /* Split this list if it is long enough for that to help. */
5825 /* Find the place in the list that bisects the list's total cost,
5826 Here I gets half the total cost. */
5831 /* Skip nodes while their cost does not reach that amount. */
5832 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5833 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5834 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5837 npp = &(*npp)->right;
5842 /* Leave this branch lopsided, but optimize left-hand
5843 side and fill in `parent' fields for right-hand side. */
5845 np->parent = parent;
5846 balance_case_nodes (&np->left, np);
5847 for (; np->right; np = np->right)
5848 np->right->parent = np;
5852 /* If there are just three nodes, split at the middle one. */
5854 npp = &(*npp)->right;
5857 /* Find the place in the list that bisects the list's total cost,
5858 where ranges count as 2.
5859 Here I gets half the total cost. */
5860 i = (i + ranges + 1) / 2;
5863 /* Skip nodes while their cost does not reach that amount. */
5864 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5869 npp = &(*npp)->right;
5874 np->parent = parent;
5877 /* Optimize each of the two split parts. */
5878 balance_case_nodes (&np->left, np);
5879 balance_case_nodes (&np->right, np);
5883 /* Else leave this branch as one level,
5884 but fill in `parent' fields. */
5886 np->parent = parent;
5887 for (; np->right; np = np->right)
5888 np->right->parent = np;
5893 /* Search the parent sections of the case node tree
5894 to see if a test for the lower bound of NODE would be redundant.
5895 INDEX_TYPE is the type of the index expression.
5897 The instructions to generate the case decision tree are
5898 output in the same order as nodes are processed so it is
5899 known that if a parent node checks the range of the current
5900 node minus one that the current node is bounded at its lower
5901 span. Thus the test would be redundant. */
5904 node_has_low_bound (node, index_type)
5909 case_node_ptr pnode;
5911 /* If the lower bound of this node is the lowest value in the index type,
5912 we need not test it. */
5914 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5917 /* If this node has a left branch, the value at the left must be less
5918 than that at this node, so it cannot be bounded at the bottom and
5919 we need not bother testing any further. */
5924 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5925 node->low, integer_one_node));
5927 /* If the subtraction above overflowed, we can't verify anything.
5928 Otherwise, look for a parent that tests our value - 1. */
5930 if (! tree_int_cst_lt (low_minus_one, node->low))
5933 for (pnode = node->parent; pnode; pnode = pnode->parent)
5934 if (tree_int_cst_equal (low_minus_one, pnode->high))
5940 /* Search the parent sections of the case node tree
5941 to see if a test for the upper bound of NODE would be redundant.
5942 INDEX_TYPE is the type of the index expression.
5944 The instructions to generate the case decision tree are
5945 output in the same order as nodes are processed so it is
5946 known that if a parent node checks the range of the current
5947 node plus one that the current node is bounded at its upper
5948 span. Thus the test would be redundant. */
5951 node_has_high_bound (node, index_type)
5956 case_node_ptr pnode;
5958 /* If there is no upper bound, obviously no test is needed. */
5960 if (TYPE_MAX_VALUE (index_type) == NULL)
5963 /* If the upper bound of this node is the highest value in the type
5964 of the index expression, we need not test against it. */
5966 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5969 /* If this node has a right branch, the value at the right must be greater
5970 than that at this node, so it cannot be bounded at the top and
5971 we need not bother testing any further. */
5976 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5977 node->high, integer_one_node));
5979 /* If the addition above overflowed, we can't verify anything.
5980 Otherwise, look for a parent that tests our value + 1. */
5982 if (! tree_int_cst_lt (node->high, high_plus_one))
5985 for (pnode = node->parent; pnode; pnode = pnode->parent)
5986 if (tree_int_cst_equal (high_plus_one, pnode->low))
5992 /* Search the parent sections of the
5993 case node tree to see if both tests for the upper and lower
5994 bounds of NODE would be redundant. */
5997 node_is_bounded (node, index_type)
6001 return (node_has_low_bound (node, index_type)
6002 && node_has_high_bound (node, index_type));
6005 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6008 emit_jump_if_reachable (label)
6011 if (GET_CODE (get_last_insn ()) != BARRIER)
6015 /* Emit step-by-step code to select a case for the value of INDEX.
6016 The thus generated decision tree follows the form of the
6017 case-node binary tree NODE, whose nodes represent test conditions.
6018 INDEX_TYPE is the type of the index of the switch.
6020 Care is taken to prune redundant tests from the decision tree
6021 by detecting any boundary conditions already checked by
6022 emitted rtx. (See node_has_high_bound, node_has_low_bound
6023 and node_is_bounded, above.)
6025 Where the test conditions can be shown to be redundant we emit
6026 an unconditional jump to the target code. As a further
6027 optimization, the subordinates of a tree node are examined to
6028 check for bounded nodes. In this case conditional and/or
6029 unconditional jumps as a result of the boundary check for the
6030 current node are arranged to target the subordinates associated
6031 code for out of bound conditions on the current node.
6033 We can assume that when control reaches the code generated here,
6034 the index value has already been compared with the parents
6035 of this node, and determined to be on the same side of each parent
6036 as this node is. Thus, if this node tests for the value 51,
6037 and a parent tested for 52, we don't need to consider
6038 the possibility of a value greater than 51. If another parent
6039 tests for the value 50, then this node need not test anything. */
6042 emit_case_nodes (index, node, default_label, index_type)
6048 /* If INDEX has an unsigned type, we must make unsigned branches. */
6049 int unsignedp = TREE_UNSIGNED (index_type);
6050 typedef rtx rtx_fn ();
6051 enum machine_mode mode = GET_MODE (index);
6053 /* See if our parents have already tested everything for us.
6054 If they have, emit an unconditional jump for this node. */
6055 if (node_is_bounded (node, index_type))
6056 emit_jump (label_rtx (node->code_label));
6058 else if (tree_int_cst_equal (node->low, node->high))
6060 /* Node is single valued. First see if the index expression matches
6061 this node and then check our children, if any. */
6063 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6064 label_rtx (node->code_label), unsignedp);
6066 if (node->right != 0 && node->left != 0)
6068 /* This node has children on both sides.
6069 Dispatch to one side or the other
6070 by comparing the index value with this node's value.
6071 If one subtree is bounded, check that one first,
6072 so we can avoid real branches in the tree. */
6074 if (node_is_bounded (node->right, index_type))
6076 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6078 GT, NULL_RTX, mode, unsignedp, 0,
6079 label_rtx (node->right->code_label));
6080 emit_case_nodes (index, node->left, default_label, index_type);
6083 else if (node_is_bounded (node->left, index_type))
6085 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6087 LT, NULL_RTX, mode, unsignedp, 0,
6088 label_rtx (node->left->code_label));
6089 emit_case_nodes (index, node->right, default_label, index_type);
6094 /* Neither node is bounded. First distinguish the two sides;
6095 then emit the code for one side at a time. */
6098 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6100 /* See if the value is on the right. */
6101 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6103 GT, NULL_RTX, mode, unsignedp, 0,
6104 label_rtx (test_label));
6106 /* Value must be on the left.
6107 Handle the left-hand subtree. */
6108 emit_case_nodes (index, node->left, default_label, index_type);
6109 /* If left-hand subtree does nothing,
6111 emit_jump_if_reachable (default_label);
6113 /* Code branches here for the right-hand subtree. */
6114 expand_label (test_label);
6115 emit_case_nodes (index, node->right, default_label, index_type);
6119 else if (node->right != 0 && node->left == 0)
6121 /* Here we have a right child but no left so we issue conditional
6122 branch to default and process the right child.
6124 Omit the conditional branch to default if we it avoid only one
6125 right child; it costs too much space to save so little time. */
6127 if (node->right->right || node->right->left
6128 || !tree_int_cst_equal (node->right->low, node->right->high))
6130 if (!node_has_low_bound (node, index_type))
6132 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6135 LT, NULL_RTX, mode, unsignedp, 0,
6139 emit_case_nodes (index, node->right, default_label, index_type);
6142 /* We cannot process node->right normally
6143 since we haven't ruled out the numbers less than
6144 this node's value. So handle node->right explicitly. */
6145 do_jump_if_equal (index,
6146 expand_expr (node->right->low, NULL_RTX,
6148 label_rtx (node->right->code_label), unsignedp);
6151 else if (node->right == 0 && node->left != 0)
6153 /* Just one subtree, on the left. */
6155 #if 0 /* The following code and comment were formerly part
6156 of the condition here, but they didn't work
6157 and I don't understand what the idea was. -- rms. */
6158 /* If our "most probable entry" is less probable
6159 than the default label, emit a jump to
6160 the default label using condition codes
6161 already lying around. With no right branch,
6162 a branch-greater-than will get us to the default
6165 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6168 if (node->left->left || node->left->right
6169 || !tree_int_cst_equal (node->left->low, node->left->high))
6171 if (!node_has_high_bound (node, index_type))
6173 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6176 GT, NULL_RTX, mode, unsignedp, 0,
6180 emit_case_nodes (index, node->left, default_label, index_type);
6183 /* We cannot process node->left normally
6184 since we haven't ruled out the numbers less than
6185 this node's value. So handle node->left explicitly. */
6186 do_jump_if_equal (index,
6187 expand_expr (node->left->low, NULL_RTX,
6189 label_rtx (node->left->code_label), unsignedp);
6194 /* Node is a range. These cases are very similar to those for a single
6195 value, except that we do not start by testing whether this node
6196 is the one to branch to. */
6198 if (node->right != 0 && node->left != 0)
6200 /* Node has subtrees on both sides.
6201 If the right-hand subtree is bounded,
6202 test for it first, since we can go straight there.
6203 Otherwise, we need to make a branch in the control structure,
6204 then handle the two subtrees. */
6205 tree test_label = 0;
6208 if (node_is_bounded (node->right, index_type))
6209 /* Right hand node is fully bounded so we can eliminate any
6210 testing and branch directly to the target code. */
6211 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6213 GT, NULL_RTX, mode, unsignedp, 0,
6214 label_rtx (node->right->code_label));
6217 /* Right hand node requires testing.
6218 Branch to a label where we will handle it later. */
6220 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6221 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6223 GT, NULL_RTX, mode, unsignedp, 0,
6224 label_rtx (test_label));
6227 /* Value belongs to this node or to the left-hand subtree. */
6229 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6231 GE, NULL_RTX, mode, unsignedp, 0,
6232 label_rtx (node->code_label));
6234 /* Handle the left-hand subtree. */
6235 emit_case_nodes (index, node->left, default_label, index_type);
6237 /* If right node had to be handled later, do that now. */
6241 /* If the left-hand subtree fell through,
6242 don't let it fall into the right-hand subtree. */
6243 emit_jump_if_reachable (default_label);
6245 expand_label (test_label);
6246 emit_case_nodes (index, node->right, default_label, index_type);
6250 else if (node->right != 0 && node->left == 0)
6252 /* Deal with values to the left of this node,
6253 if they are possible. */
6254 if (!node_has_low_bound (node, index_type))
6256 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6258 LT, NULL_RTX, mode, unsignedp, 0,
6262 /* Value belongs to this node or to the right-hand subtree. */
6264 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6266 LE, NULL_RTX, mode, unsignedp, 0,
6267 label_rtx (node->code_label));
6269 emit_case_nodes (index, node->right, default_label, index_type);
6272 else if (node->right == 0 && node->left != 0)
6274 /* Deal with values to the right of this node,
6275 if they are possible. */
6276 if (!node_has_high_bound (node, index_type))
6278 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6280 GT, NULL_RTX, mode, unsignedp, 0,
6284 /* Value belongs to this node or to the left-hand subtree. */
6286 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6288 GE, NULL_RTX, mode, unsignedp, 0,
6289 label_rtx (node->code_label));
6291 emit_case_nodes (index, node->left, default_label, index_type);
6296 /* Node has no children so we check low and high bounds to remove
6297 redundant tests. Only one of the bounds can exist,
6298 since otherwise this node is bounded--a case tested already. */
6300 if (!node_has_high_bound (node, index_type))
6302 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6304 GT, NULL_RTX, mode, unsignedp, 0,
6308 if (!node_has_low_bound (node, index_type))
6310 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6312 LT, NULL_RTX, mode, unsignedp, 0,
6316 emit_jump (label_rtx (node->code_label));
6321 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6322 so that the debugging info will be correct for the unrolled loop. */
6325 find_loop_tree_blocks ()
6327 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6331 unroll_block_trees ()
6333 tree block = DECL_INITIAL (current_function_decl);
6335 reorder_blocks (block, get_insns ());