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;
404 /* Character strings, each containing a single decimal digit. */
405 static char *digit_strings[10];
408 static int n_occurrences PROTO((int, const char *));
409 static void expand_goto_internal PROTO((tree, rtx, rtx));
410 static int expand_fixup PROTO((tree, rtx, rtx));
411 static rtx expand_nl_handler_label PROTO((rtx, rtx));
412 static void expand_nl_goto_receiver PROTO((void));
413 static void expand_nl_goto_receivers PROTO((struct nesting *));
414 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
416 static void expand_null_return_1 PROTO((rtx, int));
417 static void expand_value_return PROTO((rtx));
418 static int tail_recursion_args PROTO((tree, tree));
419 static void expand_cleanups PROTO((tree, tree, int, int));
420 static void check_seenlabel PROTO((void));
421 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
422 static int estimate_case_costs PROTO((case_node_ptr));
423 static void group_case_nodes PROTO((case_node_ptr));
424 static void balance_case_nodes PROTO((case_node_ptr *,
426 static int node_has_low_bound PROTO((case_node_ptr, tree));
427 static int node_has_high_bound PROTO((case_node_ptr, tree));
428 static int node_is_bounded PROTO((case_node_ptr, tree));
429 static void emit_jump_if_reachable PROTO((rtx));
430 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
431 static int add_case_node PROTO((tree, tree, tree, tree *));
432 static struct case_node *case_tree2list PROTO((case_node *, case_node *));
433 static void mark_cond_nesting PROTO((struct nesting *));
434 static void mark_loop_nesting PROTO((struct nesting *));
435 static void mark_block_nesting PROTO((struct nesting *));
436 static void mark_case_nesting PROTO((struct nesting *));
437 static void mark_goto_fixup PROTO((struct goto_fixup *));
441 using_eh_for_cleanups ()
443 using_eh_for_cleanups_p = 1;
446 /* Mark N (known to be a cond-nesting) for GC. */
449 mark_cond_nesting (n)
454 ggc_mark_rtx (n->exit_label);
455 ggc_mark_rtx (n->data.cond.endif_label);
456 ggc_mark_rtx (n->data.cond.next_label);
462 /* Mark N (known to be a loop-nesting) for GC. */
465 mark_loop_nesting (n)
471 ggc_mark_rtx (n->exit_label);
472 ggc_mark_rtx (n->data.loop.start_label);
473 ggc_mark_rtx (n->data.loop.end_label);
474 ggc_mark_rtx (n->data.loop.alt_end_label);
475 ggc_mark_rtx (n->data.loop.continue_label);
481 /* Mark N (known to be a block-nesting) for GC. */
484 mark_block_nesting (n)
489 struct label_chain *l;
491 ggc_mark_rtx (n->exit_label);
492 ggc_mark_rtx (n->data.block.stack_level);
493 ggc_mark_rtx (n->data.block.first_insn);
494 ggc_mark_tree (n->data.block.cleanups);
495 ggc_mark_tree (n->data.block.outer_cleanups);
497 for (l = n->data.block.label_chain; l != NULL; l = l->next)
498 ggc_mark_tree (l->label);
500 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
502 /* ??? cleanup_ptr never points outside the stack, does it? */
508 /* Mark N (known to be a case-nesting) for GC. */
511 mark_case_nesting (n)
516 struct case_node *node;
518 ggc_mark_rtx (n->exit_label);
519 ggc_mark_rtx (n->data.case_stmt.start);
521 node = n->data.case_stmt.case_list;
524 ggc_mark_tree (node->low);
525 ggc_mark_tree (node->high);
526 ggc_mark_tree (node->code_label);
530 ggc_mark_tree (n->data.case_stmt.default_label);
531 ggc_mark_tree (n->data.case_stmt.index_expr);
532 ggc_mark_tree (n->data.case_stmt.nominal_type);
542 struct goto_fixup *g;
546 ggc_mark_rtx (g->before_jump);
547 ggc_mark_tree (g->target);
548 ggc_mark_tree (g->context);
549 ggc_mark_rtx (g->target_rtl);
550 ggc_mark_rtx (g->stack_level);
551 ggc_mark_tree (g->cleanup_list_list);
557 /* Clear out all parts of the state in F that can safely be discarded
558 after the function has been compiled, to let garbage collection
559 reclaim the memory. */
565 /* We're about to free the function obstack. If we hold pointers to
566 things allocated there, then we'll try to mark them when we do
567 GC. So, we clear them out here explicitly. */
577 struct stmt_status *p;
582 mark_block_nesting (p->x_block_stack);
583 mark_cond_nesting (p->x_cond_stack);
584 mark_loop_nesting (p->x_loop_stack);
585 mark_case_nesting (p->x_case_stack);
587 ggc_mark_tree (p->x_last_expr_type);
588 /* last_epxr_value is only valid if last_expr_type is nonzero. */
589 if (p->x_last_expr_type)
590 ggc_mark_rtx (p->x_last_expr_value);
592 mark_goto_fixup (p->x_goto_fixup_chain);
600 gcc_obstack_init (&stmt_obstack);
601 ggc_add_rtx_root (&last_block_end_note, 1);
603 for (i = 0; i < 10; i++)
605 digit_strings[i] = ggc_alloc_string (NULL, 1);
606 digit_strings[i][0] = '0' + i;
608 ggc_add_string_root (digit_strings, 10);
612 init_stmt_for_function ()
614 current_function->stmt
615 = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
617 /* We are not currently within any block, conditional, loop or case. */
619 stack_block_stack = 0;
626 current_block_start_count = 0;
628 /* No gotos have been expanded yet. */
629 goto_fixup_chain = 0;
631 /* We are not processing a ({...}) grouping. */
632 expr_stmts_for_value = 0;
634 last_expr_value = NULL_RTX;
637 /* Return nonzero if anything is pushed on the loop, condition, or case
642 return cond_stack || loop_stack || case_stack;
645 /* Record the current file and line. Called from emit_line_note. */
647 set_file_and_line_for_stmt (file, line)
651 emit_filename = file;
655 /* Emit a no-op instruction. */
662 last_insn = get_last_insn ();
664 && (GET_CODE (last_insn) == CODE_LABEL
665 || (GET_CODE (last_insn) == NOTE
666 && prev_real_insn (last_insn) == 0)))
667 emit_insn (gen_nop ());
670 /* Return the rtx-label that corresponds to a LABEL_DECL,
671 creating it if necessary. */
677 if (TREE_CODE (label) != LABEL_DECL)
680 if (DECL_RTL (label))
681 return DECL_RTL (label);
683 return DECL_RTL (label) = gen_label_rtx ();
686 /* Add an unconditional jump to LABEL as the next sequential instruction. */
692 do_pending_stack_adjust ();
693 emit_jump_insn (gen_jump (label));
697 /* Emit code to jump to the address
698 specified by the pointer expression EXP. */
701 expand_computed_goto (exp)
704 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
706 #ifdef POINTERS_EXTEND_UNSIGNED
707 x = convert_memory_address (Pmode, x);
711 /* Be sure the function is executable. */
712 if (current_function_check_memory_usage)
713 emit_library_call (chkr_check_exec_libfunc, 1,
714 VOIDmode, 1, x, ptr_mode);
716 do_pending_stack_adjust ();
717 emit_indirect_jump (x);
719 current_function_has_computed_jump = 1;
722 /* Handle goto statements and the labels that they can go to. */
724 /* Specify the location in the RTL code of a label LABEL,
725 which is a LABEL_DECL tree node.
727 This is used for the kind of label that the user can jump to with a
728 goto statement, and for alternatives of a switch or case statement.
729 RTL labels generated for loops and conditionals don't go through here;
730 they are generated directly at the RTL level, by other functions below.
732 Note that this has nothing to do with defining label *names*.
733 Languages vary in how they do that and what that even means. */
739 struct label_chain *p;
741 do_pending_stack_adjust ();
742 emit_label (label_rtx (label));
743 if (DECL_NAME (label))
744 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
746 if (stack_block_stack != 0)
748 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
749 p->next = stack_block_stack->data.block.label_chain;
750 stack_block_stack->data.block.label_chain = p;
755 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
756 from nested functions. */
759 declare_nonlocal_label (label)
762 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
764 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
765 LABEL_PRESERVE_P (label_rtx (label)) = 1;
766 if (nonlocal_goto_handler_slots == 0)
768 emit_stack_save (SAVE_NONLOCAL,
769 &nonlocal_goto_stack_level,
770 PREV_INSN (tail_recursion_reentry));
772 nonlocal_goto_handler_slots
773 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
776 /* Generate RTL code for a `goto' statement with target label LABEL.
777 LABEL should be a LABEL_DECL tree node that was or will later be
778 defined with `expand_label'. */
786 /* Check for a nonlocal goto to a containing function. */
787 context = decl_function_context (label);
788 if (context != 0 && context != current_function_decl)
790 struct function *p = find_function_data (context);
791 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
792 rtx temp, handler_slot;
795 /* Find the corresponding handler slot for this label. */
796 handler_slot = p->x_nonlocal_goto_handler_slots;
797 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
798 link = TREE_CHAIN (link))
799 handler_slot = XEXP (handler_slot, 1);
800 handler_slot = XEXP (handler_slot, 0);
802 p->has_nonlocal_label = 1;
803 current_function_has_nonlocal_goto = 1;
804 LABEL_REF_NONLOCAL_P (label_ref) = 1;
806 /* Copy the rtl for the slots so that they won't be shared in
807 case the virtual stack vars register gets instantiated differently
808 in the parent than in the child. */
810 #if HAVE_nonlocal_goto
811 if (HAVE_nonlocal_goto)
812 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
813 copy_rtx (handler_slot),
814 copy_rtx (p->x_nonlocal_goto_stack_level),
821 /* Restore frame pointer for containing function.
822 This sets the actual hard register used for the frame pointer
823 to the location of the function's incoming static chain info.
824 The non-local goto handler will then adjust it to contain the
825 proper value and reload the argument pointer, if needed. */
826 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
828 /* We have now loaded the frame pointer hardware register with
829 the address of that corresponds to the start of the virtual
830 stack vars. So replace virtual_stack_vars_rtx in all
831 addresses we use with stack_pointer_rtx. */
833 /* Get addr of containing function's current nonlocal goto handler,
834 which will do any cleanups and then jump to the label. */
835 addr = copy_rtx (handler_slot);
836 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
837 hard_frame_pointer_rtx));
839 /* Restore the stack pointer. Note this uses fp just restored. */
840 addr = p->x_nonlocal_goto_stack_level;
842 addr = replace_rtx (copy_rtx (addr),
843 virtual_stack_vars_rtx,
844 hard_frame_pointer_rtx);
846 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
848 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
850 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
851 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
852 emit_indirect_jump (temp);
856 expand_goto_internal (label, label_rtx (label), NULL_RTX);
859 /* Generate RTL code for a `goto' statement with target label BODY.
860 LABEL should be a LABEL_REF.
861 LAST_INSN, if non-0, is the rtx we should consider as the last
862 insn emitted (for the purposes of cleaning up a return). */
865 expand_goto_internal (body, label, last_insn)
870 struct nesting *block;
873 if (GET_CODE (label) != CODE_LABEL)
876 /* If label has already been defined, we can tell now
877 whether and how we must alter the stack level. */
879 if (PREV_INSN (label) != 0)
881 /* Find the innermost pending block that contains the label.
882 (Check containment by comparing insn-uids.)
883 Then restore the outermost stack level within that block,
884 and do cleanups of all blocks contained in it. */
885 for (block = block_stack; block; block = block->next)
887 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
889 if (block->data.block.stack_level != 0)
890 stack_level = block->data.block.stack_level;
891 /* Execute the cleanups for blocks we are exiting. */
892 if (block->data.block.cleanups != 0)
894 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
895 do_pending_stack_adjust ();
901 /* Ensure stack adjust isn't done by emit_jump, as this
902 would clobber the stack pointer. This one should be
903 deleted as dead by flow. */
904 clear_pending_stack_adjust ();
905 do_pending_stack_adjust ();
906 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
909 if (body != 0 && DECL_TOO_LATE (body))
910 error ("jump to `%s' invalidly jumps into binding contour",
911 IDENTIFIER_POINTER (DECL_NAME (body)));
913 /* Label not yet defined: may need to put this goto
914 on the fixup list. */
915 else if (! expand_fixup (body, label, last_insn))
917 /* No fixup needed. Record that the label is the target
918 of at least one goto that has no fixup. */
920 TREE_ADDRESSABLE (body) = 1;
926 /* Generate if necessary a fixup for a goto
927 whose target label in tree structure (if any) is TREE_LABEL
928 and whose target in rtl is RTL_LABEL.
930 If LAST_INSN is nonzero, we pretend that the jump appears
931 after insn LAST_INSN instead of at the current point in the insn stream.
933 The fixup will be used later to insert insns just before the goto.
934 Those insns will restore the stack level as appropriate for the
935 target label, and will (in the case of C++) also invoke any object
936 destructors which have to be invoked when we exit the scopes which
937 are exited by the goto.
939 Value is nonzero if a fixup is made. */
942 expand_fixup (tree_label, rtl_label, last_insn)
947 struct nesting *block, *end_block;
949 /* See if we can recognize which block the label will be output in.
950 This is possible in some very common cases.
951 If we succeed, set END_BLOCK to that block.
952 Otherwise, set it to 0. */
955 && (rtl_label == cond_stack->data.cond.endif_label
956 || rtl_label == cond_stack->data.cond.next_label))
957 end_block = cond_stack;
958 /* If we are in a loop, recognize certain labels which
959 are likely targets. This reduces the number of fixups
960 we need to create. */
962 && (rtl_label == loop_stack->data.loop.start_label
963 || rtl_label == loop_stack->data.loop.end_label
964 || rtl_label == loop_stack->data.loop.continue_label))
965 end_block = loop_stack;
969 /* Now set END_BLOCK to the binding level to which we will return. */
973 struct nesting *next_block = end_block->all;
976 /* First see if the END_BLOCK is inside the innermost binding level.
977 If so, then no cleanups or stack levels are relevant. */
978 while (next_block && next_block != block)
979 next_block = next_block->all;
984 /* Otherwise, set END_BLOCK to the innermost binding level
985 which is outside the relevant control-structure nesting. */
986 next_block = block_stack->next;
987 for (block = block_stack; block != end_block; block = block->all)
988 if (block == next_block)
989 next_block = next_block->next;
990 end_block = next_block;
993 /* Does any containing block have a stack level or cleanups?
994 If not, no fixup is needed, and that is the normal case
995 (the only case, for standard C). */
996 for (block = block_stack; block != end_block; block = block->next)
997 if (block->data.block.stack_level != 0
998 || block->data.block.cleanups != 0)
1001 if (block != end_block)
1003 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1004 struct goto_fixup *fixup
1005 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1006 /* In case an old stack level is restored, make sure that comes
1007 after any pending stack adjust. */
1008 /* ?? If the fixup isn't to come at the present position,
1009 doing the stack adjust here isn't useful. Doing it with our
1010 settings at that location isn't useful either. Let's hope
1013 do_pending_stack_adjust ();
1014 fixup->target = tree_label;
1015 fixup->target_rtl = rtl_label;
1017 /* Create a BLOCK node and a corresponding matched set of
1018 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1019 this point. The notes will encapsulate any and all fixup
1020 code which we might later insert at this point in the insn
1021 stream. Also, the BLOCK node will be the parent (i.e. the
1022 `SUPERBLOCK') of any other BLOCK nodes which we might create
1023 later on when we are expanding the fixup code.
1025 Note that optimization passes (including expand_end_loop)
1026 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1027 as a placeholder. */
1030 register rtx original_before_jump
1031 = last_insn ? last_insn : get_last_insn ();
1035 block = make_node (BLOCK);
1036 TREE_USED (block) = 1;
1038 if (current_function->x_whole_function_mode_p)
1040 find_loop_tree_blocks ();
1041 retrofit_block (block, original_before_jump);
1044 insert_block (block);
1047 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1048 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1049 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1050 fixup->context = block;
1052 emit_insns_after (start, original_before_jump);
1055 fixup->block_start_count = current_block_start_count;
1056 fixup->stack_level = 0;
1057 fixup->cleanup_list_list
1058 = ((block->data.block.outer_cleanups
1059 || block->data.block.cleanups)
1060 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1061 block->data.block.outer_cleanups)
1063 fixup->next = goto_fixup_chain;
1064 goto_fixup_chain = fixup;
1072 /* Expand any needed fixups in the outputmost binding level of the
1073 function. FIRST_INSN is the first insn in the function. */
1076 expand_fixups (first_insn)
1079 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1082 /* When exiting a binding contour, process all pending gotos requiring fixups.
1083 THISBLOCK is the structure that describes the block being exited.
1084 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1085 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1086 FIRST_INSN is the insn that began this contour.
1088 Gotos that jump out of this contour must restore the
1089 stack level and do the cleanups before actually jumping.
1091 DONT_JUMP_IN nonzero means report error there is a jump into this
1092 contour from before the beginning of the contour.
1093 This is also done if STACK_LEVEL is nonzero. */
1096 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1097 struct nesting *thisblock;
1103 register struct goto_fixup *f, *prev;
1105 /* F is the fixup we are considering; PREV is the previous one. */
1106 /* We run this loop in two passes so that cleanups of exited blocks
1107 are run first, and blocks that are exited are marked so
1110 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1112 /* Test for a fixup that is inactive because it is already handled. */
1113 if (f->before_jump == 0)
1115 /* Delete inactive fixup from the chain, if that is easy to do. */
1117 prev->next = f->next;
1119 /* Has this fixup's target label been defined?
1120 If so, we can finalize it. */
1121 else if (PREV_INSN (f->target_rtl) != 0)
1123 register rtx cleanup_insns;
1125 /* Get the first non-label after the label
1126 this goto jumps to. If that's before this scope begins,
1127 we don't have a jump into the scope. */
1128 rtx after_label = f->target_rtl;
1129 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1130 after_label = NEXT_INSN (after_label);
1132 /* If this fixup jumped into this contour from before the beginning
1133 of this contour, report an error. */
1134 /* ??? Bug: this does not detect jumping in through intermediate
1135 blocks that have stack levels or cleanups.
1136 It detects only a problem with the innermost block
1137 around the label. */
1139 && (dont_jump_in || stack_level || cleanup_list)
1140 /* If AFTER_LABEL is 0, it means the jump goes to the end
1141 of the rtl, which means it jumps into this scope. */
1142 && (after_label == 0
1143 || INSN_UID (first_insn) < INSN_UID (after_label))
1144 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1145 && ! DECL_ERROR_ISSUED (f->target))
1147 error_with_decl (f->target,
1148 "label `%s' used before containing binding contour");
1149 /* Prevent multiple errors for one label. */
1150 DECL_ERROR_ISSUED (f->target) = 1;
1153 /* We will expand the cleanups into a sequence of their own and
1154 then later on we will attach this new sequence to the insn
1155 stream just ahead of the actual jump insn. */
1159 /* Temporarily restore the lexical context where we will
1160 logically be inserting the fixup code. We do this for the
1161 sake of getting the debugging information right. */
1164 set_block (f->context);
1166 /* Expand the cleanups for blocks this jump exits. */
1167 if (f->cleanup_list_list)
1170 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1171 /* Marked elements correspond to blocks that have been closed.
1172 Do their cleanups. */
1173 if (TREE_ADDRESSABLE (lists)
1174 && TREE_VALUE (lists) != 0)
1176 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1177 /* Pop any pushes done in the cleanups,
1178 in case function is about to return. */
1179 do_pending_stack_adjust ();
1183 /* Restore stack level for the biggest contour that this
1184 jump jumps out of. */
1186 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1188 /* Finish up the sequence containing the insns which implement the
1189 necessary cleanups, and then attach that whole sequence to the
1190 insn stream just ahead of the actual jump insn. Attaching it
1191 at that point insures that any cleanups which are in fact
1192 implicit C++ object destructions (which must be executed upon
1193 leaving the block) appear (to the debugger) to be taking place
1194 in an area of the generated code where the object(s) being
1195 destructed are still "in scope". */
1197 cleanup_insns = get_insns ();
1201 emit_insns_after (cleanup_insns, f->before_jump);
1208 /* For any still-undefined labels, do the cleanups for this block now.
1209 We must do this now since items in the cleanup list may go out
1210 of scope when the block ends. */
1211 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1212 if (f->before_jump != 0
1213 && PREV_INSN (f->target_rtl) == 0
1214 /* Label has still not appeared. If we are exiting a block with
1215 a stack level to restore, that started before the fixup,
1216 mark this stack level as needing restoration
1217 when the fixup is later finalized. */
1219 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1220 means the label is undefined. That's erroneous, but possible. */
1221 && (thisblock->data.block.block_start_count
1222 <= f->block_start_count))
1224 tree lists = f->cleanup_list_list;
1227 for (; lists; lists = TREE_CHAIN (lists))
1228 /* If the following elt. corresponds to our containing block
1229 then the elt. must be for this block. */
1230 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1234 set_block (f->context);
1235 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1236 do_pending_stack_adjust ();
1237 cleanup_insns = get_insns ();
1240 if (cleanup_insns != 0)
1242 = emit_insns_after (cleanup_insns, f->before_jump);
1244 f->cleanup_list_list = TREE_CHAIN (lists);
1248 f->stack_level = stack_level;
1252 /* Return the number of times character C occurs in string S. */
1254 n_occurrences (c, s)
1264 /* Generate RTL for an asm statement (explicit assembler code).
1265 BODY is a STRING_CST node containing the assembler code text,
1266 or an ADDR_EXPR containing a STRING_CST. */
1272 if (current_function_check_memory_usage)
1274 error ("`asm' cannot be used in function where memory usage is checked");
1278 if (TREE_CODE (body) == ADDR_EXPR)
1279 body = TREE_OPERAND (body, 0);
1281 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1282 TREE_STRING_POINTER (body)));
1286 /* Generate RTL for an asm statement with arguments.
1287 STRING is the instruction template.
1288 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1289 Each output or input has an expression in the TREE_VALUE and
1290 a constraint-string in the TREE_PURPOSE.
1291 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1292 that is clobbered by this insn.
1294 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1295 Some elements of OUTPUTS may be replaced with trees representing temporary
1296 values. The caller should copy those temporary values to the originally
1299 VOL nonzero means the insn is volatile; don't optimize it. */
1302 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1303 tree string, outputs, inputs, clobbers;
1308 rtvec argvec, constraints;
1310 int ninputs = list_length (inputs);
1311 int noutputs = list_length (outputs);
1316 /* Vector of RTX's of evaluated output operands. */
1317 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1318 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1319 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1320 enum machine_mode *inout_mode
1321 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1322 /* The insn we have emitted. */
1325 /* An ASM with no outputs needs to be treated as volatile, for now. */
1329 if (current_function_check_memory_usage)
1331 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1335 #ifdef MD_ASM_CLOBBERS
1336 /* Sometimes we wish to automatically clobber registers across an asm.
1337 Case in point is when the i386 backend moved from cc0 to a hard reg --
1338 maintaining source-level compatability means automatically clobbering
1339 the flags register. */
1340 MD_ASM_CLOBBERS (clobbers);
1343 if (current_function_check_memory_usage)
1345 error ("`asm' cannot be used in function where memory usage is checked");
1349 /* Count the number of meaningful clobbered registers, ignoring what
1350 we would ignore later. */
1352 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1354 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1355 i = decode_reg_name (regname);
1356 if (i >= 0 || i == -4)
1359 error ("unknown register name `%s' in `asm'", regname);
1364 /* Check that the number of alternatives is constant across all
1366 if (outputs || inputs)
1368 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1369 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1372 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1374 error ("too many alternatives in `asm'");
1381 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1382 if (n_occurrences (',', constraint) != nalternatives)
1384 error ("operand constraints for `asm' differ in number of alternatives");
1387 if (TREE_CHAIN (tmp))
1388 tmp = TREE_CHAIN (tmp);
1390 tmp = next, next = 0;
1394 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1396 tree val = TREE_VALUE (tail);
1397 tree type = TREE_TYPE (val);
1406 /* If there's an erroneous arg, emit no insn. */
1407 if (TREE_TYPE (val) == error_mark_node)
1410 /* Make sure constraint has `=' and does not have `+'. Also, see
1411 if it allows any register. Be liberal on the latter test, since
1412 the worst that happens if we get it wrong is we issue an error
1415 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1416 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1418 /* Allow the `=' or `+' to not be at the beginning of the string,
1419 since it wasn't explicitly documented that way, and there is a
1420 large body of code that puts it last. Swap the character to
1421 the front, so as not to uglify any place else. */
1425 if ((p = strchr (constraint, '=')) != NULL)
1427 if ((p = strchr (constraint, '+')) != NULL)
1430 error ("output operand constraint lacks `='");
1434 if (p != constraint)
1437 bcopy (constraint, constraint+1, p-constraint);
1440 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1443 is_inout = constraint[0] == '+';
1444 /* Replace '+' with '='. */
1445 constraint[0] = '=';
1446 /* Make sure we can specify the matching operand. */
1447 if (is_inout && i > 9)
1449 error ("output operand constraint %d contains `+'", i);
1453 for (j = 1; j < c_len; j++)
1454 switch (constraint[j])
1458 error ("operand constraint contains '+' or '=' at illegal position.");
1462 if (i + 1 == ninputs + noutputs)
1464 error ("`%%' constraint used with last operand");
1469 case '?': case '!': case '*': case '&':
1470 case 'E': case 'F': case 'G': case 'H':
1471 case 's': case 'i': case 'n':
1472 case 'I': case 'J': case 'K': case 'L': case 'M':
1473 case 'N': case 'O': case 'P': case ',':
1474 #ifdef EXTRA_CONSTRAINT
1475 case 'Q': case 'R': case 'S': case 'T': case 'U':
1479 case '0': case '1': case '2': case '3': case '4':
1480 case '5': case '6': case '7': case '8': case '9':
1481 error ("matching constraint not valid in output operand");
1484 case 'V': case 'm': case 'o':
1489 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1490 excepting those that expand_call created. So match memory
1506 /* If an output operand is not a decl or indirect ref and our constraint
1507 allows a register, make a temporary to act as an intermediate.
1508 Make the asm insn write into that, then our caller will copy it to
1509 the real output operand. Likewise for promoted variables. */
1511 real_output_rtx[i] = NULL_RTX;
1512 if ((TREE_CODE (val) == INDIRECT_REF
1514 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1515 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1516 && ! (GET_CODE (DECL_RTL (val)) == REG
1517 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1522 mark_addressable (TREE_VALUE (tail));
1525 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1526 EXPAND_MEMORY_USE_WO);
1528 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1529 error ("output number %d not directly addressable", i);
1530 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1532 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1533 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1535 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1540 output_rtx[i] = assign_temp (type, 0, 0, 0);
1541 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1546 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1547 inout_opnum[ninout++] = i;
1552 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1554 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1558 /* Make vectors for the expression-rtx and constraint strings. */
1560 argvec = rtvec_alloc (ninputs);
1561 constraints = rtvec_alloc (ninputs);
1563 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1564 empty_string, 0, argvec, constraints,
1567 MEM_VOLATILE_P (body) = vol;
1569 /* Eval the inputs and put them into ARGVEC.
1570 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1573 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1576 int allows_reg = 0, allows_mem = 0;
1577 char *constraint, *orig_constraint;
1581 /* If there's an erroneous arg, emit no insn,
1582 because the ASM_INPUT would get VOIDmode
1583 and that could cause a crash in reload. */
1584 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1587 /* ??? Can this happen, and does the error message make any sense? */
1588 if (TREE_PURPOSE (tail) == NULL_TREE)
1590 error ("hard register `%s' listed as input operand to `asm'",
1591 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1595 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1596 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1597 orig_constraint = constraint;
1599 /* Make sure constraint has neither `=', `+', nor '&'. */
1601 for (j = 0; j < c_len; j++)
1602 switch (constraint[j])
1604 case '+': case '=': case '&':
1605 if (constraint == orig_constraint)
1607 error ("input operand constraint contains `%c'", constraint[j]);
1613 if (constraint == orig_constraint
1614 && i + 1 == ninputs - ninout)
1616 error ("`%%' constraint used with last operand");
1621 case 'V': case 'm': case 'o':
1626 case '?': case '!': case '*':
1627 case 'E': case 'F': case 'G': case 'H': case 'X':
1628 case 's': case 'i': case 'n':
1629 case 'I': case 'J': case 'K': case 'L': case 'M':
1630 case 'N': case 'O': case 'P': case ',':
1631 #ifdef EXTRA_CONSTRAINT
1632 case 'Q': case 'R': case 'S': case 'T': case 'U':
1636 /* Whether or not a numeric constraint allows a register is
1637 decided by the matching constraint, and so there is no need
1638 to do anything special with them. We must handle them in
1639 the default case, so that we don't unnecessarily force
1640 operands to memory. */
1641 case '0': case '1': case '2': case '3': case '4':
1642 case '5': case '6': case '7': case '8': case '9':
1643 if (constraint[j] >= '0' + noutputs)
1646 ("matching constraint references invalid operand number");
1650 /* Try and find the real constraint for this dup. */
1651 if ((j == 0 && c_len == 1)
1652 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1655 for (j = constraint[j] - '0'; j > 0; --j)
1658 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1;
1659 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1664 /* ... fall through ... */
1677 if (! allows_reg && allows_mem)
1678 mark_addressable (TREE_VALUE (tail));
1680 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1682 if (asm_operand_ok (op, constraint) <= 0)
1685 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1686 else if (!allows_mem)
1687 warning ("asm operand %d probably doesn't match constraints", i);
1688 else if (CONSTANT_P (op))
1689 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1691 else if (GET_CODE (op) == REG
1692 || GET_CODE (op) == SUBREG
1693 || GET_CODE (op) == CONCAT)
1695 tree type = TREE_TYPE (TREE_VALUE (tail));
1696 rtx memloc = assign_temp (type, 1, 1, 1);
1698 emit_move_insn (memloc, op);
1701 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1702 /* We won't recognize volatile memory as available a
1703 memory_operand at this point. Ignore it. */
1705 else if (queued_subexp_p (op))
1708 /* ??? Leave this only until we have experience with what
1709 happens in combine and elsewhere when constraints are
1711 warning ("asm operand %d probably doesn't match constraints", i);
1713 XVECEXP (body, 3, i) = op;
1715 XVECEXP (body, 4, i) /* constraints */
1716 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1721 /* Protect all the operands from the queue,
1722 now that they have all been evaluated. */
1724 for (i = 0; i < ninputs - ninout; i++)
1725 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1727 for (i = 0; i < noutputs; i++)
1728 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1730 /* For in-out operands, copy output rtx to input rtx. */
1731 for (i = 0; i < ninout; i++)
1733 int j = inout_opnum[i];
1735 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1737 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1738 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1741 /* Now, for each output, construct an rtx
1742 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1743 ARGVEC CONSTRAINTS))
1744 If there is more than one, put them inside a PARALLEL. */
1746 if (noutputs == 1 && nclobbers == 0)
1748 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1749 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1751 else if (noutputs == 0 && nclobbers == 0)
1753 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1754 insn = emit_insn (body);
1760 if (num == 0) num = 1;
1761 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1763 /* For each output operand, store a SET. */
1765 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1767 XVECEXP (body, 0, i)
1768 = gen_rtx_SET (VOIDmode,
1770 gen_rtx_ASM_OPERANDS
1772 TREE_STRING_POINTER (string),
1773 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1774 i, argvec, constraints,
1777 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1780 /* If there are no outputs (but there are some clobbers)
1781 store the bare ASM_OPERANDS into the PARALLEL. */
1784 XVECEXP (body, 0, i++) = obody;
1786 /* Store (clobber REG) for each clobbered register specified. */
1788 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1790 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1791 int j = decode_reg_name (regname);
1795 if (j == -3) /* `cc', which is not a register */
1798 if (j == -4) /* `memory', don't cache memory across asm */
1800 XVECEXP (body, 0, i++)
1801 = gen_rtx_CLOBBER (VOIDmode,
1804 gen_rtx_SCRATCH (VOIDmode)));
1808 /* Ignore unknown register, error already signaled. */
1812 /* Use QImode since that's guaranteed to clobber just one reg. */
1813 XVECEXP (body, 0, i++)
1814 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1817 insn = emit_insn (body);
1820 /* For any outputs that needed reloading into registers, spill them
1821 back to where they belong. */
1822 for (i = 0; i < noutputs; ++i)
1823 if (real_output_rtx[i])
1824 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1829 /* Generate RTL to evaluate the expression EXP
1830 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1833 expand_expr_stmt (exp)
1836 /* If -W, warn about statements with no side effects,
1837 except for an explicit cast to void (e.g. for assert()), and
1838 except inside a ({...}) where they may be useful. */
1839 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1841 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1842 && !(TREE_CODE (exp) == CONVERT_EXPR
1843 && TREE_TYPE (exp) == void_type_node))
1844 warning_with_file_and_line (emit_filename, emit_lineno,
1845 "statement with no effect");
1846 else if (warn_unused)
1847 warn_if_unused_value (exp);
1850 /* If EXP is of function type and we are expanding statements for
1851 value, convert it to pointer-to-function. */
1852 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1853 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1855 last_expr_type = TREE_TYPE (exp);
1856 last_expr_value = expand_expr (exp,
1857 (expr_stmts_for_value
1858 ? NULL_RTX : const0_rtx),
1861 /* If all we do is reference a volatile value in memory,
1862 copy it to a register to be sure it is actually touched. */
1863 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1864 && TREE_THIS_VOLATILE (exp))
1866 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1868 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1869 copy_to_reg (last_expr_value);
1872 rtx lab = gen_label_rtx ();
1874 /* Compare the value with itself to reference it. */
1875 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1876 expand_expr (TYPE_SIZE (last_expr_type),
1877 NULL_RTX, VOIDmode, 0),
1879 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1885 /* If this expression is part of a ({...}) and is in memory, we may have
1886 to preserve temporaries. */
1887 preserve_temp_slots (last_expr_value);
1889 /* Free any temporaries used to evaluate this expression. Any temporary
1890 used as a result of this expression will already have been preserved
1897 /* Warn if EXP contains any computations whose results are not used.
1898 Return 1 if a warning is printed; 0 otherwise. */
1901 warn_if_unused_value (exp)
1904 if (TREE_USED (exp))
1907 switch (TREE_CODE (exp))
1909 case PREINCREMENT_EXPR:
1910 case POSTINCREMENT_EXPR:
1911 case PREDECREMENT_EXPR:
1912 case POSTDECREMENT_EXPR:
1917 case METHOD_CALL_EXPR:
1919 case TRY_CATCH_EXPR:
1920 case WITH_CLEANUP_EXPR:
1922 /* We don't warn about COND_EXPR because it may be a useful
1923 construct if either arm contains a side effect. */
1928 /* For a binding, warn if no side effect within it. */
1929 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1932 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1934 case TRUTH_ORIF_EXPR:
1935 case TRUTH_ANDIF_EXPR:
1936 /* In && or ||, warn if 2nd operand has no side effect. */
1937 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1940 if (TREE_NO_UNUSED_WARNING (exp))
1942 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1944 /* Let people do `(foo (), 0)' without a warning. */
1945 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1947 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1951 case NON_LVALUE_EXPR:
1952 /* Don't warn about values cast to void. */
1953 if (TREE_TYPE (exp) == void_type_node)
1955 /* Don't warn about conversions not explicit in the user's program. */
1956 if (TREE_NO_UNUSED_WARNING (exp))
1958 /* Assignment to a cast usually results in a cast of a modify.
1959 Don't complain about that. There can be an arbitrary number of
1960 casts before the modify, so we must loop until we find the first
1961 non-cast expression and then test to see if that is a modify. */
1963 tree tem = TREE_OPERAND (exp, 0);
1965 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1966 tem = TREE_OPERAND (tem, 0);
1968 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1969 || TREE_CODE (tem) == CALL_EXPR)
1975 /* Don't warn about automatic dereferencing of references, since
1976 the user cannot control it. */
1977 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1978 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1979 /* ... fall through ... */
1982 /* Referencing a volatile value is a side effect, so don't warn. */
1983 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1984 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1985 && TREE_THIS_VOLATILE (exp))
1988 warning_with_file_and_line (emit_filename, emit_lineno,
1989 "value computed is not used");
1994 /* Clear out the memory of the last expression evaluated. */
2002 /* Begin a statement which will return a value.
2003 Return the RTL_EXPR for this statement expr.
2004 The caller must save that value and pass it to expand_end_stmt_expr. */
2007 expand_start_stmt_expr ()
2012 /* Make the RTL_EXPR node temporary, not momentary,
2013 so that rtl_expr_chain doesn't become garbage. */
2014 momentary = suspend_momentary ();
2015 t = make_node (RTL_EXPR);
2016 resume_momentary (momentary);
2017 do_pending_stack_adjust ();
2018 start_sequence_for_rtl_expr (t);
2020 expr_stmts_for_value++;
2024 /* Restore the previous state at the end of a statement that returns a value.
2025 Returns a tree node representing the statement's value and the
2026 insns to compute the value.
2028 The nodes of that expression have been freed by now, so we cannot use them.
2029 But we don't want to do that anyway; the expression has already been
2030 evaluated and now we just want to use the value. So generate a RTL_EXPR
2031 with the proper type and RTL value.
2033 If the last substatement was not an expression,
2034 return something with type `void'. */
2037 expand_end_stmt_expr (t)
2042 if (last_expr_type == 0)
2044 last_expr_type = void_type_node;
2045 last_expr_value = const0_rtx;
2047 else if (last_expr_value == 0)
2048 /* There are some cases where this can happen, such as when the
2049 statement is void type. */
2050 last_expr_value = const0_rtx;
2051 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2052 /* Remove any possible QUEUED. */
2053 last_expr_value = protect_from_queue (last_expr_value, 0);
2057 TREE_TYPE (t) = last_expr_type;
2058 RTL_EXPR_RTL (t) = last_expr_value;
2059 RTL_EXPR_SEQUENCE (t) = get_insns ();
2061 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2065 /* Don't consider deleting this expr or containing exprs at tree level. */
2066 TREE_SIDE_EFFECTS (t) = 1;
2067 /* Propagate volatility of the actual RTL expr. */
2068 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2071 expr_stmts_for_value--;
2076 /* Generate RTL for the start of an if-then. COND is the expression
2077 whose truth should be tested.
2079 If EXITFLAG is nonzero, this conditional is visible to
2080 `exit_something'. */
2083 expand_start_cond (cond, exitflag)
2087 struct nesting *thiscond = ALLOC_NESTING ();
2089 /* Make an entry on cond_stack for the cond we are entering. */
2091 thiscond->next = cond_stack;
2092 thiscond->all = nesting_stack;
2093 thiscond->depth = ++nesting_depth;
2094 thiscond->data.cond.next_label = gen_label_rtx ();
2095 /* Before we encounter an `else', we don't need a separate exit label
2096 unless there are supposed to be exit statements
2097 to exit this conditional. */
2098 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2099 thiscond->data.cond.endif_label = thiscond->exit_label;
2100 cond_stack = thiscond;
2101 nesting_stack = thiscond;
2103 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2106 /* Generate RTL between then-clause and the elseif-clause
2107 of an if-then-elseif-.... */
2110 expand_start_elseif (cond)
2113 if (cond_stack->data.cond.endif_label == 0)
2114 cond_stack->data.cond.endif_label = gen_label_rtx ();
2115 emit_jump (cond_stack->data.cond.endif_label);
2116 emit_label (cond_stack->data.cond.next_label);
2117 cond_stack->data.cond.next_label = gen_label_rtx ();
2118 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2121 /* Generate RTL between the then-clause and the else-clause
2122 of an if-then-else. */
2125 expand_start_else ()
2127 if (cond_stack->data.cond.endif_label == 0)
2128 cond_stack->data.cond.endif_label = gen_label_rtx ();
2130 emit_jump (cond_stack->data.cond.endif_label);
2131 emit_label (cond_stack->data.cond.next_label);
2132 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2135 /* After calling expand_start_else, turn this "else" into an "else if"
2136 by providing another condition. */
2139 expand_elseif (cond)
2142 cond_stack->data.cond.next_label = gen_label_rtx ();
2143 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2146 /* Generate RTL for the end of an if-then.
2147 Pop the record for it off of cond_stack. */
2152 struct nesting *thiscond = cond_stack;
2154 do_pending_stack_adjust ();
2155 if (thiscond->data.cond.next_label)
2156 emit_label (thiscond->data.cond.next_label);
2157 if (thiscond->data.cond.endif_label)
2158 emit_label (thiscond->data.cond.endif_label);
2160 POPSTACK (cond_stack);
2166 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2167 loop should be exited by `exit_something'. This is a loop for which
2168 `expand_continue' will jump to the top of the loop.
2170 Make an entry on loop_stack to record the labels associated with
2174 expand_start_loop (exit_flag)
2177 register struct nesting *thisloop = ALLOC_NESTING ();
2179 /* Make an entry on loop_stack for the loop we are entering. */
2181 thisloop->next = loop_stack;
2182 thisloop->all = nesting_stack;
2183 thisloop->depth = ++nesting_depth;
2184 thisloop->data.loop.start_label = gen_label_rtx ();
2185 thisloop->data.loop.end_label = gen_label_rtx ();
2186 thisloop->data.loop.alt_end_label = 0;
2187 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2188 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2189 loop_stack = thisloop;
2190 nesting_stack = thisloop;
2192 do_pending_stack_adjust ();
2194 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2195 emit_label (thisloop->data.loop.start_label);
2200 /* Like expand_start_loop but for a loop where the continuation point
2201 (for expand_continue_loop) will be specified explicitly. */
2204 expand_start_loop_continue_elsewhere (exit_flag)
2207 struct nesting *thisloop = expand_start_loop (exit_flag);
2208 loop_stack->data.loop.continue_label = gen_label_rtx ();
2212 /* Specify the continuation point for a loop started with
2213 expand_start_loop_continue_elsewhere.
2214 Use this at the point in the code to which a continue statement
2218 expand_loop_continue_here ()
2220 do_pending_stack_adjust ();
2221 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2222 emit_label (loop_stack->data.loop.continue_label);
2225 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2226 Pop the block off of loop_stack. */
2231 rtx start_label = loop_stack->data.loop.start_label;
2232 rtx insn = get_last_insn ();
2233 int needs_end_jump = 1;
2235 /* Mark the continue-point at the top of the loop if none elsewhere. */
2236 if (start_label == loop_stack->data.loop.continue_label)
2237 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2239 do_pending_stack_adjust ();
2241 /* If optimizing, perhaps reorder the loop.
2242 First, try to use a condjump near the end.
2243 expand_exit_loop_if_false ends loops with unconditional jumps,
2246 if (test) goto label;
2248 goto loop_stack->data.loop.end_label
2252 If we find such a pattern, we can end the loop earlier. */
2255 && GET_CODE (insn) == CODE_LABEL
2256 && LABEL_NAME (insn) == NULL
2257 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2260 rtx jump = PREV_INSN (PREV_INSN (label));
2262 if (GET_CODE (jump) == JUMP_INSN
2263 && GET_CODE (PATTERN (jump)) == SET
2264 && SET_DEST (PATTERN (jump)) == pc_rtx
2265 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2266 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2267 == loop_stack->data.loop.end_label))
2271 /* The test might be complex and reference LABEL multiple times,
2272 like the loop in loop_iterations to set vtop. To handle this,
2274 insn = PREV_INSN (label);
2275 reorder_insns (label, label, start_label);
2277 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2279 /* We ignore line number notes, but if we see any other note,
2280 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2281 NOTE_INSN_LOOP_*, we disable this optimization. */
2282 if (GET_CODE (prev) == NOTE)
2284 if (NOTE_LINE_NUMBER (prev) < 0)
2288 if (GET_CODE (prev) == CODE_LABEL)
2290 if (GET_CODE (prev) == JUMP_INSN)
2292 if (GET_CODE (PATTERN (prev)) == SET
2293 && SET_DEST (PATTERN (prev)) == pc_rtx
2294 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2295 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2297 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2299 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2301 emit_note_after (NOTE_INSN_LOOP_END, prev);
2310 /* If the loop starts with a loop exit, roll that to the end where
2311 it will optimize together with the jump back.
2313 We look for the conditional branch to the exit, except that once
2314 we find such a branch, we don't look past 30 instructions.
2316 In more detail, if the loop presently looks like this (in pseudo-C):
2319 if (test) goto end_label;
2324 transform it to look like:
2330 if (test) goto end_label;
2331 goto newstart_label;
2334 Here, the `test' may actually consist of some reasonably complex
2335 code, terminating in a test. */
2340 ! (GET_CODE (insn) == JUMP_INSN
2341 && GET_CODE (PATTERN (insn)) == SET
2342 && SET_DEST (PATTERN (insn)) == pc_rtx
2343 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2347 rtx last_test_insn = NULL_RTX;
2349 /* Scan insns from the top of the loop looking for a qualified
2350 conditional exit. */
2351 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2352 insn = NEXT_INSN (insn))
2354 if (GET_CODE (insn) == NOTE)
2357 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2358 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2359 /* The code that actually moves the exit test will
2360 carefully leave BLOCK notes in their original
2361 location. That means, however, that we can't debug
2362 the exit test itself. So, we refuse to move code
2363 containing BLOCK notes at low optimization levels. */
2366 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2368 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2372 /* We've come to the end of an EH region, but
2373 never saw the beginning of that region. That
2374 means that an EH region begins before the top
2375 of the loop, and ends in the middle of it. The
2376 existence of such a situation violates a basic
2377 assumption in this code, since that would imply
2378 that even when EH_REGIONS is zero, we might
2379 move code out of an exception region. */
2383 /* We must not walk into a nested loop. */
2384 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2387 /* We already know this INSN is a NOTE, so there's no
2388 point in looking at it to see if it's a JUMP. */
2392 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2395 if (last_test_insn && num_insns > 30)
2399 /* We don't want to move a partial EH region. Consider:
2413 This isn't legal C++, but here's what it's supposed to
2414 mean: if cond() is true, stop looping. Otherwise,
2415 call bar, and keep looping. In addition, if cond
2416 throws an exception, catch it and keep looping. Such
2417 constructs are certainy legal in LISP.
2419 We should not move the `if (cond()) 0' test since then
2420 the EH-region for the try-block would be broken up.
2421 (In this case we would the EH_BEG note for the `try'
2422 and `if cond()' but not the call to bar() or the
2425 So we don't look for tests within an EH region. */
2428 if (GET_CODE (insn) == JUMP_INSN
2429 && GET_CODE (PATTERN (insn)) == SET
2430 && SET_DEST (PATTERN (insn)) == pc_rtx)
2432 /* This is indeed a jump. */
2433 rtx dest1 = NULL_RTX;
2434 rtx dest2 = NULL_RTX;
2435 rtx potential_last_test;
2436 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2438 /* A conditional jump. */
2439 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2440 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2441 potential_last_test = insn;
2445 /* An unconditional jump. */
2446 dest1 = SET_SRC (PATTERN (insn));
2447 /* Include the BARRIER after the JUMP. */
2448 potential_last_test = NEXT_INSN (insn);
2452 if (dest1 && GET_CODE (dest1) == LABEL_REF
2453 && ((XEXP (dest1, 0)
2454 == loop_stack->data.loop.alt_end_label)
2456 == loop_stack->data.loop.end_label)))
2458 last_test_insn = potential_last_test;
2462 /* If this was a conditional jump, there may be
2463 another label at which we should look. */
2470 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2472 /* We found one. Move everything from there up
2473 to the end of the loop, and add a jump into the loop
2474 to jump to there. */
2475 register rtx newstart_label = gen_label_rtx ();
2476 register rtx start_move = start_label;
2479 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2480 then we want to move this note also. */
2481 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2482 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2483 == NOTE_INSN_LOOP_CONT))
2484 start_move = PREV_INSN (start_move);
2486 emit_label_after (newstart_label, PREV_INSN (start_move));
2488 /* Actually move the insns. Start at the beginning, and
2489 keep copying insns until we've copied the
2491 for (insn = start_move; insn; insn = next_insn)
2493 /* Figure out which insn comes after this one. We have
2494 to do this before we move INSN. */
2495 if (insn == last_test_insn)
2496 /* We've moved all the insns. */
2497 next_insn = NULL_RTX;
2499 next_insn = NEXT_INSN (insn);
2501 if (GET_CODE (insn) == NOTE
2502 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2503 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2504 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2505 NOTE_INSN_BLOCK_ENDs because the correct generation
2506 of debugging information depends on these appearing
2507 in the same order in the RTL and in the tree
2508 structure, where they are represented as BLOCKs.
2509 So, we don't move block notes. Of course, moving
2510 the code inside the block is likely to make it
2511 impossible to debug the instructions in the exit
2512 test, but such is the price of optimization. */
2515 /* Move the INSN. */
2516 reorder_insns (insn, insn, get_last_insn ());
2519 emit_jump_insn_after (gen_jump (start_label),
2520 PREV_INSN (newstart_label));
2521 emit_barrier_after (PREV_INSN (newstart_label));
2522 start_label = newstart_label;
2528 emit_jump (start_label);
2529 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2531 emit_label (loop_stack->data.loop.end_label);
2533 POPSTACK (loop_stack);
2538 /* Generate a jump to the current loop's continue-point.
2539 This is usually the top of the loop, but may be specified
2540 explicitly elsewhere. If not currently inside a loop,
2541 return 0 and do nothing; caller will print an error message. */
2544 expand_continue_loop (whichloop)
2545 struct nesting *whichloop;
2549 whichloop = loop_stack;
2552 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2557 /* Generate a jump to exit the current loop. If not currently inside a loop,
2558 return 0 and do nothing; caller will print an error message. */
2561 expand_exit_loop (whichloop)
2562 struct nesting *whichloop;
2566 whichloop = loop_stack;
2569 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2573 /* Generate a conditional jump to exit the current loop if COND
2574 evaluates to zero. If not currently inside a loop,
2575 return 0 and do nothing; caller will print an error message. */
2578 expand_exit_loop_if_false (whichloop, cond)
2579 struct nesting *whichloop;
2582 rtx label = gen_label_rtx ();
2587 whichloop = loop_stack;
2590 /* In order to handle fixups, we actually create a conditional jump
2591 around a unconditional branch to exit the loop. If fixups are
2592 necessary, they go before the unconditional branch. */
2595 do_jump (cond, NULL_RTX, label);
2596 last_insn = get_last_insn ();
2597 if (GET_CODE (last_insn) == CODE_LABEL)
2598 whichloop->data.loop.alt_end_label = last_insn;
2599 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2606 /* Return nonzero if the loop nest is empty. Else return zero. */
2609 stmt_loop_nest_empty ()
2611 return (loop_stack == NULL);
2614 /* Return non-zero if we should preserve sub-expressions as separate
2615 pseudos. We never do so if we aren't optimizing. We always do so
2616 if -fexpensive-optimizations.
2618 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2619 the loop may still be a small one. */
2622 preserve_subexpressions_p ()
2626 if (flag_expensive_optimizations)
2629 if (optimize == 0 || current_function == 0
2630 || current_function->stmt == 0 || loop_stack == 0)
2633 insn = get_last_insn_anywhere ();
2636 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2637 < n_non_fixed_regs * 3));
2641 /* Generate a jump to exit the current loop, conditional, binding contour
2642 or case statement. Not all such constructs are visible to this function,
2643 only those started with EXIT_FLAG nonzero. Individual languages use
2644 the EXIT_FLAG parameter to control which kinds of constructs you can
2647 If not currently inside anything that can be exited,
2648 return 0 and do nothing; caller will print an error message. */
2651 expand_exit_something ()
2655 for (n = nesting_stack; n; n = n->all)
2656 if (n->exit_label != 0)
2658 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2665 /* Generate RTL to return from the current function, with no value.
2666 (That is, we do not do anything about returning any value.) */
2669 expand_null_return ()
2671 struct nesting *block = block_stack;
2674 /* Does any pending block have cleanups? */
2676 while (block && block->data.block.cleanups == 0)
2677 block = block->next;
2679 /* If yes, use a goto to return, since that runs cleanups. */
2681 expand_null_return_1 (last_insn, block != 0);
2684 /* Generate RTL to return from the current function, with value VAL. */
2687 expand_value_return (val)
2690 struct nesting *block = block_stack;
2691 rtx last_insn = get_last_insn ();
2692 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2694 /* Copy the value to the return location
2695 unless it's already there. */
2697 if (return_reg != val)
2699 #ifdef PROMOTE_FUNCTION_RETURN
2700 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2701 int unsignedp = TREE_UNSIGNED (type);
2702 enum machine_mode mode
2703 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2706 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2707 convert_move (return_reg, val, unsignedp);
2710 emit_move_insn (return_reg, val);
2712 if (GET_CODE (return_reg) == REG
2713 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2714 emit_insn (gen_rtx_USE (VOIDmode, return_reg));
2715 /* Handle calls that return values in multiple non-contiguous locations.
2716 The Irix 6 ABI has examples of this. */
2717 else if (GET_CODE (return_reg) == PARALLEL)
2721 for (i = 0; i < XVECLEN (return_reg, 0); i++)
2723 rtx x = XEXP (XVECEXP (return_reg, 0, i), 0);
2725 if (GET_CODE (x) == REG
2726 && REGNO (x) < FIRST_PSEUDO_REGISTER)
2727 emit_insn (gen_rtx_USE (VOIDmode, x));
2731 /* Does any pending block have cleanups? */
2733 while (block && block->data.block.cleanups == 0)
2734 block = block->next;
2736 /* If yes, use a goto to return, since that runs cleanups.
2737 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2739 expand_null_return_1 (last_insn, block != 0);
2742 /* Output a return with no value. If LAST_INSN is nonzero,
2743 pretend that the return takes place after LAST_INSN.
2744 If USE_GOTO is nonzero then don't use a return instruction;
2745 go to the return label instead. This causes any cleanups
2746 of pending blocks to be executed normally. */
2749 expand_null_return_1 (last_insn, use_goto)
2753 rtx end_label = cleanup_label ? cleanup_label : return_label;
2755 clear_pending_stack_adjust ();
2756 do_pending_stack_adjust ();
2759 /* PCC-struct return always uses an epilogue. */
2760 if (current_function_returns_pcc_struct || use_goto)
2763 end_label = return_label = gen_label_rtx ();
2764 expand_goto_internal (NULL_TREE, end_label, last_insn);
2768 /* Otherwise output a simple return-insn if one is available,
2769 unless it won't do the job. */
2771 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2773 emit_jump_insn (gen_return ());
2779 /* Otherwise jump to the epilogue. */
2780 expand_goto_internal (NULL_TREE, end_label, last_insn);
2783 /* Generate RTL to evaluate the expression RETVAL and return it
2784 from the current function. */
2787 expand_return (retval)
2790 /* If there are any cleanups to be performed, then they will
2791 be inserted following LAST_INSN. It is desirable
2792 that the last_insn, for such purposes, should be the
2793 last insn before computing the return value. Otherwise, cleanups
2794 which call functions can clobber the return value. */
2795 /* ??? rms: I think that is erroneous, because in C++ it would
2796 run destructors on variables that might be used in the subsequent
2797 computation of the return value. */
2799 register rtx val = 0;
2804 /* If function wants no value, give it none. */
2805 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2807 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2809 expand_null_return ();
2813 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2814 /* This is not sufficient. We also need to watch for cleanups of the
2815 expression we are about to expand. Unfortunately, we cannot know
2816 if it has cleanups until we expand it, and we want to change how we
2817 expand it depending upon if we need cleanups. We can't win. */
2819 cleanups = any_pending_cleanups (1);
2824 if (TREE_CODE (retval) == RESULT_DECL)
2825 retval_rhs = retval;
2826 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2827 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2828 retval_rhs = TREE_OPERAND (retval, 1);
2829 else if (TREE_TYPE (retval) == void_type_node)
2830 /* Recognize tail-recursive call to void function. */
2831 retval_rhs = retval;
2833 retval_rhs = NULL_TREE;
2835 /* Only use `last_insn' if there are cleanups which must be run. */
2836 if (cleanups || cleanup_label != 0)
2837 last_insn = get_last_insn ();
2839 /* Distribute return down conditional expr if either of the sides
2840 may involve tail recursion (see test below). This enhances the number
2841 of tail recursions we see. Don't do this always since it can produce
2842 sub-optimal code in some cases and we distribute assignments into
2843 conditional expressions when it would help. */
2845 if (optimize && retval_rhs != 0
2846 && frame_offset == 0
2847 && TREE_CODE (retval_rhs) == COND_EXPR
2848 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2849 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2851 rtx label = gen_label_rtx ();
2854 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2855 start_cleanup_deferral ();
2856 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2857 DECL_RESULT (current_function_decl),
2858 TREE_OPERAND (retval_rhs, 1));
2859 TREE_SIDE_EFFECTS (expr) = 1;
2860 expand_return (expr);
2863 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2864 DECL_RESULT (current_function_decl),
2865 TREE_OPERAND (retval_rhs, 2));
2866 TREE_SIDE_EFFECTS (expr) = 1;
2867 expand_return (expr);
2868 end_cleanup_deferral ();
2872 /* Attempt to optimize the call if it is tail recursive. */
2873 if (optimize_tail_recursion (retval_rhs, last_insn))
2877 /* This optimization is safe if there are local cleanups
2878 because expand_null_return takes care of them.
2879 ??? I think it should also be safe when there is a cleanup label,
2880 because expand_null_return takes care of them, too.
2881 Any reason why not? */
2882 if (HAVE_return && cleanup_label == 0
2883 && ! current_function_returns_pcc_struct
2884 && BRANCH_COST <= 1)
2886 /* If this is return x == y; then generate
2887 if (x == y) return 1; else return 0;
2888 if we can do it with explicit return insns and branches are cheap,
2889 but not if we have the corresponding scc insn. */
2892 switch (TREE_CODE (retval_rhs))
2918 case TRUTH_ANDIF_EXPR:
2919 case TRUTH_ORIF_EXPR:
2920 case TRUTH_AND_EXPR:
2922 case TRUTH_NOT_EXPR:
2923 case TRUTH_XOR_EXPR:
2926 op0 = gen_label_rtx ();
2927 jumpifnot (retval_rhs, op0);
2928 expand_value_return (const1_rtx);
2930 expand_value_return (const0_rtx);
2939 #endif /* HAVE_return */
2941 /* If the result is an aggregate that is being returned in one (or more)
2942 registers, load the registers here. The compiler currently can't handle
2943 copying a BLKmode value into registers. We could put this code in a
2944 more general area (for use by everyone instead of just function
2945 call/return), but until this feature is generally usable it is kept here
2946 (and in expand_call). The value must go into a pseudo in case there
2947 are cleanups that will clobber the real return register. */
2950 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2951 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2953 int i, bitpos, xbitpos;
2954 int big_endian_correction = 0;
2955 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2956 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2957 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2958 (unsigned int)BITS_PER_WORD);
2959 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2960 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2961 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2962 enum machine_mode tmpmode, result_reg_mode;
2964 /* Structures whose size is not a multiple of a word are aligned
2965 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2966 machine, this means we must skip the empty high order bytes when
2967 calculating the bit offset. */
2968 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2969 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2972 /* Copy the structure BITSIZE bits at a time. */
2973 for (bitpos = 0, xbitpos = big_endian_correction;
2974 bitpos < bytes * BITS_PER_UNIT;
2975 bitpos += bitsize, xbitpos += bitsize)
2977 /* We need a new destination pseudo each time xbitpos is
2978 on a word boundary and when xbitpos == big_endian_correction
2979 (the first time through). */
2980 if (xbitpos % BITS_PER_WORD == 0
2981 || xbitpos == big_endian_correction)
2983 /* Generate an appropriate register. */
2984 dst = gen_reg_rtx (word_mode);
2985 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2987 /* Clobber the destination before we move anything into it. */
2988 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2991 /* We need a new source operand each time bitpos is on a word
2993 if (bitpos % BITS_PER_WORD == 0)
2994 src = operand_subword_force (result_val,
2995 bitpos / BITS_PER_WORD,
2998 /* Use bitpos for the source extraction (left justified) and
2999 xbitpos for the destination store (right justified). */
3000 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3001 extract_bit_field (src, bitsize,
3002 bitpos % BITS_PER_WORD, 1,
3003 NULL_RTX, word_mode,
3005 bitsize / BITS_PER_UNIT,
3007 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
3010 /* Find the smallest integer mode large enough to hold the
3011 entire structure and use that mode instead of BLKmode
3012 on the USE insn for the return register. */
3013 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3014 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3015 tmpmode != VOIDmode;
3016 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3018 /* Have we found a large enough mode? */
3019 if (GET_MODE_SIZE (tmpmode) >= bytes)
3023 /* No suitable mode found. */
3024 if (tmpmode == VOIDmode)
3027 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
3029 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3030 result_reg_mode = word_mode;
3032 result_reg_mode = tmpmode;
3033 result_reg = gen_reg_rtx (result_reg_mode);
3036 for (i = 0; i < n_regs; i++)
3037 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3040 if (tmpmode != result_reg_mode)
3041 result_reg = gen_lowpart (tmpmode, result_reg);
3043 expand_value_return (result_reg);
3047 && TREE_TYPE (retval_rhs) != void_type_node
3048 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
3050 /* Calculate the return value into a pseudo reg. */
3051 val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl)));
3052 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3053 val = force_not_mem (val);
3055 /* Return the calculated value, doing cleanups first. */
3056 expand_value_return (val);
3060 /* No cleanups or no hard reg used;
3061 calculate value into hard return reg. */
3062 expand_expr (retval, const0_rtx, VOIDmode, 0);
3064 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
3068 /* Return 1 if the end of the generated RTX is not a barrier.
3069 This means code already compiled can drop through. */
3072 drop_through_at_end_p ()
3074 rtx insn = get_last_insn ();
3075 while (insn && GET_CODE (insn) == NOTE)
3076 insn = PREV_INSN (insn);
3077 return insn && GET_CODE (insn) != BARRIER;
3080 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3081 and emit code to optimize the tail recursion. LAST_INSN indicates where
3082 to place the jump to the tail recursion label. Return TRUE if the
3083 call was optimized into a goto.
3085 This is only used by expand_return, but expand_call is expected to
3089 optimize_tail_recursion (call_expr, last_insn)
3093 /* For tail-recursive call to current function,
3094 just jump back to the beginning.
3095 It's unsafe if any auto variable in this function
3096 has its address taken; for simplicity,
3097 require stack frame to be empty. */
3098 if (optimize && call_expr != 0
3099 && frame_offset == 0
3100 && TREE_CODE (call_expr) == CALL_EXPR
3101 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3102 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3103 /* Finish checking validity, and if valid emit code
3104 to set the argument variables for the new call. */
3105 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3106 DECL_ARGUMENTS (current_function_decl)))
3108 if (tail_recursion_label == 0)
3110 tail_recursion_label = gen_label_rtx ();
3111 emit_label_after (tail_recursion_label,
3112 tail_recursion_reentry);
3115 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3123 /* Emit code to alter this function's formal parms for a tail-recursive call.
3124 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3125 FORMALS is the chain of decls of formals.
3126 Return 1 if this can be done;
3127 otherwise return 0 and do not emit any code. */
3130 tail_recursion_args (actuals, formals)
3131 tree actuals, formals;
3133 register tree a = actuals, f = formals;
3135 register rtx *argvec;
3137 /* Check that number and types of actuals are compatible
3138 with the formals. This is not always true in valid C code.
3139 Also check that no formal needs to be addressable
3140 and that all formals are scalars. */
3142 /* Also count the args. */
3144 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3146 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3147 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3149 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3152 if (a != 0 || f != 0)
3155 /* Compute all the actuals. */
3157 argvec = (rtx *) alloca (i * sizeof (rtx));
3159 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3160 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3162 /* Find which actual values refer to current values of previous formals.
3163 Copy each of them now, before any formal is changed. */
3165 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3169 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3170 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3171 { copy = 1; break; }
3173 argvec[i] = copy_to_reg (argvec[i]);
3176 /* Store the values of the actuals into the formals. */
3178 for (f = formals, a = actuals, i = 0; f;
3179 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3181 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3182 emit_move_insn (DECL_RTL (f), argvec[i]);
3184 convert_move (DECL_RTL (f), argvec[i],
3185 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3192 /* Generate the RTL code for entering a binding contour.
3193 The variables are declared one by one, by calls to `expand_decl'.
3195 FLAGS is a bitwise or of the following flags:
3197 1 - Nonzero if this construct should be visible to
3200 2 - Nonzero if this contour does not require a
3201 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3202 language-independent code should set this flag because they
3203 will not create corresponding BLOCK nodes. (There should be
3204 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3205 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3206 when expand_end_bindings is called. */
3209 expand_start_bindings (flags)
3212 struct nesting *thisblock = ALLOC_NESTING ();
3214 int exit_flag = ((flags & 1) != 0);
3215 int block_flag = ((flags & 2) == 0);
3217 note = emit_note (NULL_PTR,
3218 block_flag ? NOTE_INSN_BLOCK_BEG : NOTE_INSN_DELETED);
3220 /* Make an entry on block_stack for the block we are entering. */
3222 thisblock->next = block_stack;
3223 thisblock->all = nesting_stack;
3224 thisblock->depth = ++nesting_depth;
3225 thisblock->data.block.stack_level = 0;
3226 thisblock->data.block.cleanups = 0;
3227 thisblock->data.block.n_function_calls = 0;
3228 thisblock->data.block.exception_region = 0;
3229 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3231 thisblock->data.block.conditional_code = 0;
3232 thisblock->data.block.last_unconditional_cleanup = note;
3233 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3236 && !(block_stack->data.block.cleanups == NULL_TREE
3237 && block_stack->data.block.outer_cleanups == NULL_TREE))
3238 thisblock->data.block.outer_cleanups
3239 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3240 block_stack->data.block.outer_cleanups);
3242 thisblock->data.block.outer_cleanups = 0;
3243 thisblock->data.block.label_chain = 0;
3244 thisblock->data.block.innermost_stack_block = stack_block_stack;
3245 thisblock->data.block.first_insn = note;
3246 thisblock->data.block.block_start_count = ++current_block_start_count;
3247 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3248 block_stack = thisblock;
3249 nesting_stack = thisblock;
3251 /* Make a new level for allocating stack slots. */
3255 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3256 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3257 expand_expr are made. After we end the region, we know that all
3258 space for all temporaries that were created by TARGET_EXPRs will be
3259 destroyed and their space freed for reuse. */
3262 expand_start_target_temps ()
3264 /* This is so that even if the result is preserved, the space
3265 allocated will be freed, as we know that it is no longer in use. */
3268 /* Start a new binding layer that will keep track of all cleanup
3269 actions to be performed. */
3270 expand_start_bindings (2);
3272 target_temp_slot_level = temp_slot_level;
3276 expand_end_target_temps ()
3278 expand_end_bindings (NULL_TREE, 0, 0);
3280 /* This is so that even if the result is preserved, the space
3281 allocated will be freed, as we know that it is no longer in use. */
3285 /* Mark top block of block_stack as an implicit binding for an
3286 exception region. This is used to prevent infinite recursion when
3287 ending a binding with expand_end_bindings. It is only ever called
3288 by expand_eh_region_start, as that it the only way to create a
3289 block stack for a exception region. */
3292 mark_block_as_eh_region ()
3294 block_stack->data.block.exception_region = 1;
3295 if (block_stack->next
3296 && block_stack->next->data.block.conditional_code)
3298 block_stack->data.block.conditional_code
3299 = block_stack->next->data.block.conditional_code;
3300 block_stack->data.block.last_unconditional_cleanup
3301 = block_stack->next->data.block.last_unconditional_cleanup;
3302 block_stack->data.block.cleanup_ptr
3303 = block_stack->next->data.block.cleanup_ptr;
3307 /* True if we are currently emitting insns in an area of output code
3308 that is controlled by a conditional expression. This is used by
3309 the cleanup handling code to generate conditional cleanup actions. */
3312 conditional_context ()
3314 return block_stack && block_stack->data.block.conditional_code;
3317 /* Mark top block of block_stack as not for an implicit binding for an
3318 exception region. This is only ever done by expand_eh_region_end
3319 to let expand_end_bindings know that it is being called explicitly
3320 to end the binding layer for just the binding layer associated with
3321 the exception region, otherwise expand_end_bindings would try and
3322 end all implicit binding layers for exceptions regions, and then
3323 one normal binding layer. */
3326 mark_block_as_not_eh_region ()
3328 block_stack->data.block.exception_region = 0;
3331 /* True if the top block of block_stack was marked as for an exception
3332 region by mark_block_as_eh_region. */
3337 return (current_function && block_stack
3338 && block_stack->data.block.exception_region);
3341 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3342 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3346 remember_end_note (block)
3347 register tree block;
3349 BLOCK_END_NOTE (block) = last_block_end_note;
3350 last_block_end_note = NULL_RTX;
3353 /* Emit a handler label for a nonlocal goto handler.
3354 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3357 expand_nl_handler_label (slot, before_insn)
3358 rtx slot, before_insn;
3361 rtx handler_label = gen_label_rtx ();
3363 /* Don't let jump_optimize delete the handler. */
3364 LABEL_PRESERVE_P (handler_label) = 1;
3367 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3368 insns = get_insns ();
3370 emit_insns_before (insns, before_insn);
3372 emit_label (handler_label);
3374 return handler_label;
3377 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3380 expand_nl_goto_receiver ()
3382 #ifdef HAVE_nonlocal_goto
3383 if (! HAVE_nonlocal_goto)
3385 /* First adjust our frame pointer to its actual value. It was
3386 previously set to the start of the virtual area corresponding to
3387 the stacked variables when we branched here and now needs to be
3388 adjusted to the actual hardware fp value.
3390 Assignments are to virtual registers are converted by
3391 instantiate_virtual_regs into the corresponding assignment
3392 to the underlying register (fp in this case) that makes
3393 the original assignment true.
3394 So the following insn will actually be
3395 decrementing fp by STARTING_FRAME_OFFSET. */
3396 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3398 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3399 if (fixed_regs[ARG_POINTER_REGNUM])
3401 #ifdef ELIMINABLE_REGS
3402 /* If the argument pointer can be eliminated in favor of the
3403 frame pointer, we don't need to restore it. We assume here
3404 that if such an elimination is present, it can always be used.
3405 This is the case on all known machines; if we don't make this
3406 assumption, we do unnecessary saving on many machines. */
3407 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3410 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3411 if (elim_regs[i].from == ARG_POINTER_REGNUM
3412 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3415 if (i == sizeof elim_regs / sizeof elim_regs [0])
3418 /* Now restore our arg pointer from the address at which it
3419 was saved in our stack frame.
3420 If there hasn't be space allocated for it yet, make
3422 if (arg_pointer_save_area == 0)
3423 arg_pointer_save_area
3424 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3425 emit_move_insn (virtual_incoming_args_rtx,
3426 /* We need a pseudo here, or else
3427 instantiate_virtual_regs_1 complains. */
3428 copy_to_reg (arg_pointer_save_area));
3433 #ifdef HAVE_nonlocal_goto_receiver
3434 if (HAVE_nonlocal_goto_receiver)
3435 emit_insn (gen_nonlocal_goto_receiver ());
3439 /* Make handlers for nonlocal gotos taking place in the function calls in
3443 expand_nl_goto_receivers (thisblock)
3444 struct nesting *thisblock;
3447 rtx afterward = gen_label_rtx ();
3452 /* Record the handler address in the stack slot for that purpose,
3453 during this block, saving and restoring the outer value. */
3454 if (thisblock->next != 0)
3455 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3457 rtx save_receiver = gen_reg_rtx (Pmode);
3458 emit_move_insn (XEXP (slot, 0), save_receiver);
3461 emit_move_insn (save_receiver, XEXP (slot, 0));
3462 insns = get_insns ();
3464 emit_insns_before (insns, thisblock->data.block.first_insn);
3467 /* Jump around the handlers; they run only when specially invoked. */
3468 emit_jump (afterward);
3470 /* Make a separate handler for each label. */
3471 link = nonlocal_labels;
3472 slot = nonlocal_goto_handler_slots;
3473 label_list = NULL_RTX;
3474 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3475 /* Skip any labels we shouldn't be able to jump to from here,
3476 we generate one special handler for all of them below which just calls
3478 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3481 lab = expand_nl_handler_label (XEXP (slot, 0),
3482 thisblock->data.block.first_insn);
3483 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3485 expand_nl_goto_receiver ();
3487 /* Jump to the "real" nonlocal label. */
3488 expand_goto (TREE_VALUE (link));
3491 /* A second pass over all nonlocal labels; this time we handle those
3492 we should not be able to jump to at this point. */
3493 link = nonlocal_labels;
3494 slot = nonlocal_goto_handler_slots;
3496 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3497 if (DECL_TOO_LATE (TREE_VALUE (link)))
3500 lab = expand_nl_handler_label (XEXP (slot, 0),
3501 thisblock->data.block.first_insn);
3502 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3508 expand_nl_goto_receiver ();
3509 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3514 nonlocal_goto_handler_labels = label_list;
3515 emit_label (afterward);
3518 /* Warn about any unused VARS (which may contain nodes other than
3519 VAR_DECLs, but such nodes are ignored). The nodes are connected
3520 via the TREE_CHAIN field. */
3523 warn_about_unused_variables (vars)
3529 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3530 if (TREE_CODE (decl) == VAR_DECL
3531 && ! TREE_USED (decl)
3532 && ! DECL_IN_SYSTEM_HEADER (decl)
3533 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3534 warning_with_decl (decl, "unused variable `%s'");
3537 /* Generate RTL code to terminate a binding contour.
3539 VARS is the chain of VAR_DECL nodes for the variables bound in this
3540 contour. There may actually be other nodes in this chain, but any
3541 nodes other than VAR_DECLS are ignored.
3543 MARK_ENDS is nonzero if we should put a note at the beginning
3544 and end of this binding contour.
3546 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3547 (That is true automatically if the contour has a saved stack level.) */
3550 expand_end_bindings (vars, mark_ends, dont_jump_in)
3555 register struct nesting *thisblock;
3558 while (block_stack->data.block.exception_region)
3560 /* Because we don't need or want a new temporary level and
3561 because we didn't create one in expand_eh_region_start,
3562 create a fake one now to avoid removing one in
3563 expand_end_bindings. */
3566 block_stack->data.block.exception_region = 0;
3568 expand_end_bindings (NULL_TREE, 0, 0);
3571 /* Since expand_eh_region_start does an expand_start_bindings, we
3572 have to first end all the bindings that were created by
3573 expand_eh_region_start. */
3575 thisblock = block_stack;
3577 /* If any of the variables in this scope were not used, warn the
3579 warn_about_unused_variables (vars);
3581 if (thisblock->exit_label)
3583 do_pending_stack_adjust ();
3584 emit_label (thisblock->exit_label);
3587 /* If necessary, make handlers for nonlocal gotos taking
3588 place in the function calls in this block. */
3589 if (function_call_count != thisblock->data.block.n_function_calls
3591 /* Make handler for outermost block
3592 if there were any nonlocal gotos to this function. */
3593 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3594 /* Make handler for inner block if it has something
3595 special to do when you jump out of it. */
3596 : (thisblock->data.block.cleanups != 0
3597 || thisblock->data.block.stack_level != 0)))
3598 expand_nl_goto_receivers (thisblock);
3600 /* Don't allow jumping into a block that has a stack level.
3601 Cleanups are allowed, though. */
3603 || thisblock->data.block.stack_level != 0)
3605 struct label_chain *chain;
3607 /* Any labels in this block are no longer valid to go to.
3608 Mark them to cause an error message. */
3609 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3611 DECL_TOO_LATE (chain->label) = 1;
3612 /* If any goto without a fixup came to this label,
3613 that must be an error, because gotos without fixups
3614 come from outside all saved stack-levels. */
3615 if (TREE_ADDRESSABLE (chain->label))
3616 error_with_decl (chain->label,
3617 "label `%s' used before containing binding contour");
3621 /* Restore stack level in effect before the block
3622 (only if variable-size objects allocated). */
3623 /* Perform any cleanups associated with the block. */
3625 if (thisblock->data.block.stack_level != 0
3626 || thisblock->data.block.cleanups != 0)
3628 /* Only clean up here if this point can actually be reached. */
3629 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3631 /* Don't let cleanups affect ({...}) constructs. */
3632 int old_expr_stmts_for_value = expr_stmts_for_value;
3633 rtx old_last_expr_value = last_expr_value;
3634 tree old_last_expr_type = last_expr_type;
3635 expr_stmts_for_value = 0;
3637 /* Do the cleanups. */
3638 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3640 do_pending_stack_adjust ();
3642 expr_stmts_for_value = old_expr_stmts_for_value;
3643 last_expr_value = old_last_expr_value;
3644 last_expr_type = old_last_expr_type;
3646 /* Restore the stack level. */
3648 if (reachable && thisblock->data.block.stack_level != 0)
3650 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3651 thisblock->data.block.stack_level, NULL_RTX);
3652 if (nonlocal_goto_handler_slots != 0)
3653 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3657 /* Any gotos out of this block must also do these things.
3658 Also report any gotos with fixups that came to labels in this
3660 fixup_gotos (thisblock,
3661 thisblock->data.block.stack_level,
3662 thisblock->data.block.cleanups,
3663 thisblock->data.block.first_insn,
3667 /* Mark the beginning and end of the scope if requested.
3668 We do this now, after running cleanups on the variables
3669 just going out of scope, so they are in scope for their cleanups. */
3672 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3674 /* Get rid of the beginning-mark if we don't make an end-mark. */
3675 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3677 /* If doing stupid register allocation, make sure lives of all
3678 register variables declared here extend thru end of scope. */
3681 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3682 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
3683 use_variable (DECL_RTL (decl));
3685 /* Restore the temporary level of TARGET_EXPRs. */
3686 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3688 /* Restore block_stack level for containing block. */
3690 stack_block_stack = thisblock->data.block.innermost_stack_block;
3691 POPSTACK (block_stack);
3693 /* Pop the stack slot nesting and free any slots at this level. */
3697 /* Generate RTL for the automatic variable declaration DECL.
3698 (Other kinds of declarations are simply ignored if seen here.) */
3704 struct nesting *thisblock;
3707 type = TREE_TYPE (decl);
3709 /* Only automatic variables need any expansion done.
3710 Static and external variables, and external functions,
3711 will be handled by `assemble_variable' (called from finish_decl).
3712 TYPE_DECL and CONST_DECL require nothing.
3713 PARM_DECLs are handled in `assign_parms'. */
3715 if (TREE_CODE (decl) != VAR_DECL)
3717 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3720 thisblock = block_stack;
3722 /* Create the RTL representation for the variable. */
3724 if (type == error_mark_node)
3725 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3726 else if (DECL_SIZE (decl) == 0)
3727 /* Variable with incomplete type. */
3729 if (DECL_INITIAL (decl) == 0)
3730 /* Error message was already done; now avoid a crash. */
3731 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3733 /* An initializer is going to decide the size of this array.
3734 Until we know the size, represent its address with a reg. */
3735 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3736 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3738 else if (DECL_MODE (decl) != BLKmode
3739 /* If -ffloat-store, don't put explicit float vars
3741 && !(flag_float_store
3742 && TREE_CODE (type) == REAL_TYPE)
3743 && ! TREE_THIS_VOLATILE (decl)
3744 && ! TREE_ADDRESSABLE (decl)
3745 && (DECL_REGISTER (decl) || ! obey_regdecls)
3746 /* if -fcheck-memory-usage, check all variables. */
3747 && ! current_function_check_memory_usage)
3749 /* Automatic variable that can go in a register. */
3750 int unsignedp = TREE_UNSIGNED (type);
3751 enum machine_mode reg_mode
3752 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3754 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3755 mark_user_reg (DECL_RTL (decl));
3757 if (POINTER_TYPE_P (type))
3758 mark_reg_pointer (DECL_RTL (decl),
3759 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3763 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3764 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3765 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3766 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3767 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3769 /* Variable of fixed size that goes on the stack. */
3773 /* If we previously made RTL for this decl, it must be an array
3774 whose size was determined by the initializer.
3775 The old address was a register; set that register now
3776 to the proper address. */
3777 if (DECL_RTL (decl) != 0)
3779 if (GET_CODE (DECL_RTL (decl)) != MEM
3780 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3782 oldaddr = XEXP (DECL_RTL (decl), 0);
3785 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3786 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3787 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3789 /* Set alignment we actually gave this decl. */
3790 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3791 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3795 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3796 if (addr != oldaddr)
3797 emit_move_insn (oldaddr, addr);
3800 /* If this is a memory ref that contains aggregate components,
3801 mark it as such for cse and loop optimize. */
3802 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3803 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3805 /* If this is in memory because of -ffloat-store,
3806 set the volatile bit, to prevent optimizations from
3807 undoing the effects. */
3808 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3809 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3812 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3815 /* Dynamic-size object: must push space on the stack. */
3819 /* Record the stack pointer on entry to block, if have
3820 not already done so. */
3821 if (thisblock->data.block.stack_level == 0)
3823 do_pending_stack_adjust ();
3824 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3825 &thisblock->data.block.stack_level,
3826 thisblock->data.block.first_insn);
3827 stack_block_stack = thisblock;
3830 /* Compute the variable's size, in bytes. */
3831 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3833 size_int (BITS_PER_UNIT)),
3834 NULL_RTX, VOIDmode, 0);
3837 /* Allocate space on the stack for the variable. Note that
3838 DECL_ALIGN says how the variable is to be aligned and we
3839 cannot use it to conclude anything about the alignment of
3841 address = allocate_dynamic_stack_space (size, NULL_RTX,
3842 TYPE_ALIGN (TREE_TYPE (decl)));
3844 /* Reference the variable indirect through that rtx. */
3845 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3847 /* If this is a memory ref that contains aggregate components,
3848 mark it as such for cse and loop optimize. */
3849 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3850 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3852 /* Indicate the alignment we actually gave this variable. */
3853 #ifdef STACK_BOUNDARY
3854 DECL_ALIGN (decl) = STACK_BOUNDARY;
3856 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3860 if (TREE_THIS_VOLATILE (decl))
3861 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3862 #if 0 /* A variable is not necessarily unchanging
3863 just because it is const. RTX_UNCHANGING_P
3864 means no change in the function,
3865 not merely no change in the variable's scope.
3866 It is correct to set RTX_UNCHANGING_P if the variable's scope
3867 is the whole function. There's no convenient way to test that. */
3868 if (TREE_READONLY (decl))
3869 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3872 /* If doing stupid register allocation, make sure life of any
3873 register variable starts here, at the start of its scope. */
3876 use_variable (DECL_RTL (decl));
3881 /* Emit code to perform the initialization of a declaration DECL. */
3884 expand_decl_init (decl)
3887 int was_used = TREE_USED (decl);
3889 /* If this is a CONST_DECL, we don't have to generate any code, but
3890 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3891 to be set while in the obstack containing the constant. If we don't
3892 do this, we can lose if we have functions nested three deep and the middle
3893 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3894 the innermost function is the first to expand that STRING_CST. */
3895 if (TREE_CODE (decl) == CONST_DECL)
3897 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3898 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3899 EXPAND_INITIALIZER);
3903 if (TREE_STATIC (decl))
3906 /* Compute and store the initial value now. */
3908 if (DECL_INITIAL (decl) == error_mark_node)
3910 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3912 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3913 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3914 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3918 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3920 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3921 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3925 /* Don't let the initialization count as "using" the variable. */
3926 TREE_USED (decl) = was_used;
3928 /* Free any temporaries we made while initializing the decl. */
3929 preserve_temp_slots (NULL_RTX);
3933 /* CLEANUP is an expression to be executed at exit from this binding contour;
3934 for example, in C++, it might call the destructor for this variable.
3936 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3937 CLEANUP multiple times, and have the correct semantics. This
3938 happens in exception handling, for gotos, returns, breaks that
3939 leave the current scope.
3941 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3942 that is not associated with any particular variable. */
3945 expand_decl_cleanup (decl, cleanup)
3948 struct nesting *thisblock;
3950 /* Error if we are not in any block. */
3951 if (current_function == 0 || block_stack == 0)
3954 thisblock = block_stack;
3956 /* Record the cleanup if there is one. */
3962 tree *cleanups = &thisblock->data.block.cleanups;
3963 int cond_context = conditional_context ();
3967 rtx flag = gen_reg_rtx (word_mode);
3972 emit_move_insn (flag, const0_rtx);
3973 set_flag_0 = get_insns ();
3976 thisblock->data.block.last_unconditional_cleanup
3977 = emit_insns_after (set_flag_0,
3978 thisblock->data.block.last_unconditional_cleanup);
3980 emit_move_insn (flag, const1_rtx);
3982 /* All cleanups must be on the function_obstack. */
3983 push_obstacks_nochange ();
3984 resume_temporary_allocation ();
3986 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3987 DECL_RTL (cond) = flag;
3989 /* Conditionalize the cleanup. */
3990 cleanup = build (COND_EXPR, void_type_node,
3991 truthvalue_conversion (cond),
3992 cleanup, integer_zero_node);
3993 cleanup = fold (cleanup);
3997 cleanups = thisblock->data.block.cleanup_ptr;
4000 /* All cleanups must be on the function_obstack. */
4001 push_obstacks_nochange ();
4002 resume_temporary_allocation ();
4003 cleanup = unsave_expr (cleanup);
4006 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4009 /* If this block has a cleanup, it belongs in stack_block_stack. */
4010 stack_block_stack = thisblock;
4017 /* If this was optimized so that there is no exception region for the
4018 cleanup, then mark the TREE_LIST node, so that we can later tell
4019 if we need to call expand_eh_region_end. */
4020 if (! using_eh_for_cleanups_p
4021 || expand_eh_region_start_tree (decl, cleanup))
4022 TREE_ADDRESSABLE (t) = 1;
4023 /* If that started a new EH region, we're in a new block. */
4024 thisblock = block_stack;
4031 thisblock->data.block.last_unconditional_cleanup
4032 = emit_insns_after (seq,
4033 thisblock->data.block.last_unconditional_cleanup);
4037 thisblock->data.block.last_unconditional_cleanup
4039 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4045 /* Like expand_decl_cleanup, but suppress generating an exception handler
4046 to perform the cleanup. */
4049 expand_decl_cleanup_no_eh (decl, cleanup)
4052 int save_eh = using_eh_for_cleanups_p;
4055 using_eh_for_cleanups_p = 0;
4056 result = expand_decl_cleanup (decl, cleanup);
4057 using_eh_for_cleanups_p = save_eh;
4062 /* Arrange for the top element of the dynamic cleanup chain to be
4063 popped if we exit the current binding contour. DECL is the
4064 associated declaration, if any, otherwise NULL_TREE. If the
4065 current contour is left via an exception, then __sjthrow will pop
4066 the top element off the dynamic cleanup chain. The code that
4067 avoids doing the action we push into the cleanup chain in the
4068 exceptional case is contained in expand_cleanups.
4070 This routine is only used by expand_eh_region_start, and that is
4071 the only way in which an exception region should be started. This
4072 routine is only used when using the setjmp/longjmp codegen method
4073 for exception handling. */
4076 expand_dcc_cleanup (decl)
4079 struct nesting *thisblock;
4082 /* Error if we are not in any block. */
4083 if (current_function == 0 || block_stack == 0)
4085 thisblock = block_stack;
4087 /* Record the cleanup for the dynamic handler chain. */
4089 /* All cleanups must be on the function_obstack. */
4090 push_obstacks_nochange ();
4091 resume_temporary_allocation ();
4092 cleanup = make_node (POPDCC_EXPR);
4095 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4096 thisblock->data.block.cleanups
4097 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4099 /* If this block has a cleanup, it belongs in stack_block_stack. */
4100 stack_block_stack = thisblock;
4104 /* Arrange for the top element of the dynamic handler chain to be
4105 popped if we exit the current binding contour. DECL is the
4106 associated declaration, if any, otherwise NULL_TREE. If the current
4107 contour is left via an exception, then __sjthrow will pop the top
4108 element off the dynamic handler chain. The code that avoids doing
4109 the action we push into the handler chain in the exceptional case
4110 is contained in expand_cleanups.
4112 This routine is only used by expand_eh_region_start, and that is
4113 the only way in which an exception region should be started. This
4114 routine is only used when using the setjmp/longjmp codegen method
4115 for exception handling. */
4118 expand_dhc_cleanup (decl)
4121 struct nesting *thisblock;
4124 /* Error if we are not in any block. */
4125 if (current_function == 0 || block_stack == 0)
4127 thisblock = block_stack;
4129 /* Record the cleanup for the dynamic handler chain. */
4131 /* All cleanups must be on the function_obstack. */
4132 push_obstacks_nochange ();
4133 resume_temporary_allocation ();
4134 cleanup = make_node (POPDHC_EXPR);
4137 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4138 thisblock->data.block.cleanups
4139 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4141 /* If this block has a cleanup, it belongs in stack_block_stack. */
4142 stack_block_stack = thisblock;
4146 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4147 DECL_ELTS is the list of elements that belong to DECL's type.
4148 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4151 expand_anon_union_decl (decl, cleanup, decl_elts)
4152 tree decl, cleanup, decl_elts;
4154 struct nesting *thisblock = current_function == 0 ? 0 : block_stack;
4158 expand_decl_cleanup (decl, cleanup);
4159 x = DECL_RTL (decl);
4163 tree decl_elt = TREE_VALUE (decl_elts);
4164 tree cleanup_elt = TREE_PURPOSE (decl_elts);
4165 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4167 /* Propagate the union's alignment to the elements. */
4168 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4170 /* If the element has BLKmode and the union doesn't, the union is
4171 aligned such that the element doesn't need to have BLKmode, so
4172 change the element's mode to the appropriate one for its size. */
4173 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4174 DECL_MODE (decl_elt) = mode
4175 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4178 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4179 instead create a new MEM rtx with the proper mode. */
4180 if (GET_CODE (x) == MEM)
4182 if (mode == GET_MODE (x))
4183 DECL_RTL (decl_elt) = x;
4186 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4187 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4188 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4191 else if (GET_CODE (x) == REG)
4193 if (mode == GET_MODE (x))
4194 DECL_RTL (decl_elt) = x;
4196 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4201 /* Record the cleanup if there is one. */
4204 thisblock->data.block.cleanups
4205 = temp_tree_cons (decl_elt, cleanup_elt,
4206 thisblock->data.block.cleanups);
4208 decl_elts = TREE_CHAIN (decl_elts);
4212 /* Expand a list of cleanups LIST.
4213 Elements may be expressions or may be nested lists.
4215 If DONT_DO is nonnull, then any list-element
4216 whose TREE_PURPOSE matches DONT_DO is omitted.
4217 This is sometimes used to avoid a cleanup associated with
4218 a value that is being returned out of the scope.
4220 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4221 goto and handle protection regions specially in that case.
4223 If REACHABLE, we emit code, otherwise just inform the exception handling
4224 code about this finalization. */
4227 expand_cleanups (list, dont_do, in_fixup, reachable)
4234 for (tail = list; tail; tail = TREE_CHAIN (tail))
4235 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4237 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4238 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4243 tree cleanup = TREE_VALUE (tail);
4245 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4246 if (TREE_CODE (cleanup) != POPDHC_EXPR
4247 && TREE_CODE (cleanup) != POPDCC_EXPR
4248 /* See expand_eh_region_start_tree for this case. */
4249 && ! TREE_ADDRESSABLE (tail))
4251 cleanup = protect_with_terminate (cleanup);
4252 expand_eh_region_end (cleanup);
4258 /* Cleanups may be run multiple times. For example,
4259 when exiting a binding contour, we expand the
4260 cleanups associated with that contour. When a goto
4261 within that binding contour has a target outside that
4262 contour, it will expand all cleanups from its scope to
4263 the target. Though the cleanups are expanded multiple
4264 times, the control paths are non-overlapping so the
4265 cleanups will not be executed twice. */
4267 /* We may need to protect fixups with rethrow regions. */
4268 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4271 expand_fixup_region_start ();
4273 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4275 expand_fixup_region_end (TREE_VALUE (tail));
4282 /* Mark when the context we are emitting RTL for as a conditional
4283 context, so that any cleanup actions we register with
4284 expand_decl_init will be properly conditionalized when those
4285 cleanup actions are later performed. Must be called before any
4286 expression (tree) is expanded that is within a conditional context. */
4289 start_cleanup_deferral ()
4291 /* block_stack can be NULL if we are inside the parameter list. It is
4292 OK to do nothing, because cleanups aren't possible here. */
4294 ++block_stack->data.block.conditional_code;
4297 /* Mark the end of a conditional region of code. Because cleanup
4298 deferrals may be nested, we may still be in a conditional region
4299 after we end the currently deferred cleanups, only after we end all
4300 deferred cleanups, are we back in unconditional code. */
4303 end_cleanup_deferral ()
4305 /* block_stack can be NULL if we are inside the parameter list. It is
4306 OK to do nothing, because cleanups aren't possible here. */
4308 --block_stack->data.block.conditional_code;
4311 /* Move all cleanups from the current block_stack
4312 to the containing block_stack, where they are assumed to
4313 have been created. If anything can cause a temporary to
4314 be created, but not expanded for more than one level of
4315 block_stacks, then this code will have to change. */
4320 struct nesting *block = block_stack;
4321 struct nesting *outer = block->next;
4323 outer->data.block.cleanups
4324 = chainon (block->data.block.cleanups,
4325 outer->data.block.cleanups);
4326 block->data.block.cleanups = 0;
4330 last_cleanup_this_contour ()
4332 if (block_stack == 0)
4335 return block_stack->data.block.cleanups;
4338 /* Return 1 if there are any pending cleanups at this point.
4339 If THIS_CONTOUR is nonzero, check the current contour as well.
4340 Otherwise, look only at the contours that enclose this one. */
4343 any_pending_cleanups (this_contour)
4346 struct nesting *block;
4348 if (current_function == NULL || current_function->stmt == NULL
4349 || block_stack == 0)
4352 if (this_contour && block_stack->data.block.cleanups != NULL)
4354 if (block_stack->data.block.cleanups == 0
4355 && block_stack->data.block.outer_cleanups == 0)
4358 for (block = block_stack->next; block; block = block->next)
4359 if (block->data.block.cleanups != 0)
4365 /* Enter a case (Pascal) or switch (C) statement.
4366 Push a block onto case_stack and nesting_stack
4367 to accumulate the case-labels that are seen
4368 and to record the labels generated for the statement.
4370 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4371 Otherwise, this construct is transparent for `exit_something'.
4373 EXPR is the index-expression to be dispatched on.
4374 TYPE is its nominal type. We could simply convert EXPR to this type,
4375 but instead we take short cuts. */
4378 expand_start_case (exit_flag, expr, type, printname)
4382 const char *printname;
4384 register struct nesting *thiscase = ALLOC_NESTING ();
4386 /* Make an entry on case_stack for the case we are entering. */
4388 thiscase->next = case_stack;
4389 thiscase->all = nesting_stack;
4390 thiscase->depth = ++nesting_depth;
4391 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4392 thiscase->data.case_stmt.case_list = 0;
4393 thiscase->data.case_stmt.index_expr = expr;
4394 thiscase->data.case_stmt.nominal_type = type;
4395 thiscase->data.case_stmt.default_label = 0;
4396 thiscase->data.case_stmt.num_ranges = 0;
4397 thiscase->data.case_stmt.printname = printname;
4398 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4399 case_stack = thiscase;
4400 nesting_stack = thiscase;
4402 do_pending_stack_adjust ();
4404 /* Make sure case_stmt.start points to something that won't
4405 need any transformation before expand_end_case. */
4406 if (GET_CODE (get_last_insn ()) != NOTE)
4407 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4409 thiscase->data.case_stmt.start = get_last_insn ();
4411 start_cleanup_deferral ();
4415 /* Start a "dummy case statement" within which case labels are invalid
4416 and are not connected to any larger real case statement.
4417 This can be used if you don't want to let a case statement jump
4418 into the middle of certain kinds of constructs. */
4421 expand_start_case_dummy ()
4423 register struct nesting *thiscase = ALLOC_NESTING ();
4425 /* Make an entry on case_stack for the dummy. */
4427 thiscase->next = case_stack;
4428 thiscase->all = nesting_stack;
4429 thiscase->depth = ++nesting_depth;
4430 thiscase->exit_label = 0;
4431 thiscase->data.case_stmt.case_list = 0;
4432 thiscase->data.case_stmt.start = 0;
4433 thiscase->data.case_stmt.nominal_type = 0;
4434 thiscase->data.case_stmt.default_label = 0;
4435 thiscase->data.case_stmt.num_ranges = 0;
4436 case_stack = thiscase;
4437 nesting_stack = thiscase;
4438 start_cleanup_deferral ();
4441 /* End a dummy case statement. */
4444 expand_end_case_dummy ()
4446 end_cleanup_deferral ();
4447 POPSTACK (case_stack);
4450 /* Return the data type of the index-expression
4451 of the innermost case statement, or null if none. */
4454 case_index_expr_type ()
4457 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4464 /* If this is the first label, warn if any insns have been emitted. */
4465 if (case_stack->data.case_stmt.line_number_status >= 0)
4469 restore_line_number_status
4470 (case_stack->data.case_stmt.line_number_status);
4471 case_stack->data.case_stmt.line_number_status = -1;
4473 for (insn = case_stack->data.case_stmt.start;
4475 insn = NEXT_INSN (insn))
4477 if (GET_CODE (insn) == CODE_LABEL)
4479 if (GET_CODE (insn) != NOTE
4480 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4483 insn = PREV_INSN (insn);
4484 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4486 /* If insn is zero, then there must have been a syntax error. */
4488 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4489 NOTE_LINE_NUMBER(insn),
4490 "unreachable code at beginning of %s",
4491 case_stack->data.case_stmt.printname);
4498 /* Accumulate one case or default label inside a case or switch statement.
4499 VALUE is the value of the case (a null pointer, for a default label).
4500 The function CONVERTER, when applied to arguments T and V,
4501 converts the value V to the type T.
4503 If not currently inside a case or switch statement, return 1 and do
4504 nothing. The caller will print a language-specific error message.
4505 If VALUE is a duplicate or overlaps, return 2 and do nothing
4506 except store the (first) duplicate node in *DUPLICATE.
4507 If VALUE is out of range, return 3 and do nothing.
4508 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4509 Return 0 on success.
4511 Extended to handle range statements. */
4514 pushcase (value, converter, label, duplicate)
4515 register tree value;
4516 tree (*converter) PROTO((tree, tree));
4517 register tree label;
4523 /* Fail if not inside a real case statement. */
4524 if (! (case_stack && case_stack->data.case_stmt.start))
4527 if (stack_block_stack
4528 && stack_block_stack->depth > case_stack->depth)
4531 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4532 nominal_type = case_stack->data.case_stmt.nominal_type;
4534 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4535 if (index_type == error_mark_node)
4538 /* Convert VALUE to the type in which the comparisons are nominally done. */
4540 value = (*converter) (nominal_type, value);
4544 /* Fail if this value is out of range for the actual type of the index
4545 (which may be narrower than NOMINAL_TYPE). */
4546 if (value != 0 && ! int_fits_type_p (value, index_type))
4549 /* Fail if this is a duplicate or overlaps another entry. */
4552 if (case_stack->data.case_stmt.default_label != 0)
4554 *duplicate = case_stack->data.case_stmt.default_label;
4557 case_stack->data.case_stmt.default_label = label;
4560 return add_case_node (value, value, label, duplicate);
4562 expand_label (label);
4566 /* Like pushcase but this case applies to all values between VALUE1 and
4567 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4568 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4569 starts at VALUE1 and ends at the highest value of the index type.
4570 If both are NULL, this case applies to all values.
4572 The return value is the same as that of pushcase but there is one
4573 additional error code: 4 means the specified range was empty. */
4576 pushcase_range (value1, value2, converter, label, duplicate)
4577 register tree value1, value2;
4578 tree (*converter) PROTO((tree, tree));
4579 register tree label;
4585 /* Fail if not inside a real case statement. */
4586 if (! (case_stack && case_stack->data.case_stmt.start))
4589 if (stack_block_stack
4590 && stack_block_stack->depth > case_stack->depth)
4593 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4594 nominal_type = case_stack->data.case_stmt.nominal_type;
4596 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4597 if (index_type == error_mark_node)
4602 /* Convert VALUEs to type in which the comparisons are nominally done
4603 and replace any unspecified value with the corresponding bound. */
4605 value1 = TYPE_MIN_VALUE (index_type);
4607 value2 = TYPE_MAX_VALUE (index_type);
4609 /* Fail if the range is empty. Do this before any conversion since
4610 we want to allow out-of-range empty ranges. */
4611 if (value2 && tree_int_cst_lt (value2, value1))
4614 value1 = (*converter) (nominal_type, value1);
4616 /* If the max was unbounded, use the max of the nominal_type we are
4617 converting to. Do this after the < check above to suppress false
4620 value2 = TYPE_MAX_VALUE (nominal_type);
4621 value2 = (*converter) (nominal_type, value2);
4623 /* Fail if these values are out of range. */
4624 if (TREE_CONSTANT_OVERFLOW (value1)
4625 || ! int_fits_type_p (value1, index_type))
4628 if (TREE_CONSTANT_OVERFLOW (value2)
4629 || ! int_fits_type_p (value2, index_type))
4632 return add_case_node (value1, value2, label, duplicate);
4635 /* Do the actual insertion of a case label for pushcase and pushcase_range
4636 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4637 slowdown for large switch statements. */
4640 add_case_node (low, high, label, duplicate)
4645 struct case_node *p, **q, *r;
4647 q = &case_stack->data.case_stmt.case_list;
4654 /* Keep going past elements distinctly greater than HIGH. */
4655 if (tree_int_cst_lt (high, p->low))
4658 /* or distinctly less than LOW. */
4659 else if (tree_int_cst_lt (p->high, low))
4664 /* We have an overlap; this is an error. */
4665 *duplicate = p->code_label;
4670 /* Add this label to the chain, and succeed.
4671 Copy LOW, HIGH so they are on temporary rather than momentary
4672 obstack and will thus survive till the end of the case statement. */
4674 r = (struct case_node *) oballoc (sizeof (struct case_node));
4675 r->low = copy_node (low);
4677 /* If the bounds are equal, turn this into the one-value case. */
4679 if (tree_int_cst_equal (low, high))
4683 r->high = copy_node (high);
4684 case_stack->data.case_stmt.num_ranges++;
4687 r->code_label = label;
4688 expand_label (label);
4698 struct case_node *s;
4704 if (! (b = p->balance))
4705 /* Growth propagation from left side. */
4712 if ((p->left = s = r->right))
4721 if ((r->parent = s))
4729 case_stack->data.case_stmt.case_list = r;
4732 /* r->balance == +1 */
4737 struct case_node *t = r->right;
4739 if ((p->left = s = t->right))
4743 if ((r->right = s = t->left))
4757 if ((t->parent = s))
4765 case_stack->data.case_stmt.case_list = t;
4772 /* p->balance == +1; growth of left side balances the node. */
4782 if (! (b = p->balance))
4783 /* Growth propagation from right side. */
4791 if ((p->right = s = r->left))
4799 if ((r->parent = s))
4808 case_stack->data.case_stmt.case_list = r;
4812 /* r->balance == -1 */
4816 struct case_node *t = r->left;
4818 if ((p->right = s = t->left))
4823 if ((r->left = s = t->right))
4837 if ((t->parent = s))
4846 case_stack->data.case_stmt.case_list = t;
4852 /* p->balance == -1; growth of right side balances the node. */
4866 /* Returns the number of possible values of TYPE.
4867 Returns -1 if the number is unknown or variable.
4868 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4869 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4870 do not increase monotonically (there may be duplicates);
4871 to 1 if the values increase monotonically, but not always by 1;
4872 otherwise sets it to 0. */
4875 all_cases_count (type, spareness)
4879 HOST_WIDE_INT count;
4882 switch (TREE_CODE (type))
4889 count = 1 << BITS_PER_UNIT;
4893 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4894 || TYPE_MAX_VALUE (type) == NULL
4895 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4900 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4901 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4902 but with overflow checking. */
4903 tree mint = TYPE_MIN_VALUE (type);
4904 tree maxt = TYPE_MAX_VALUE (type);
4905 HOST_WIDE_INT lo, hi;
4906 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4908 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4910 add_double (lo, hi, 1, 0, &lo, &hi);
4911 if (hi != 0 || lo < 0)
4918 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4920 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4921 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4922 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4923 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4927 if (*spareness == 1)
4929 tree prev = TREE_VALUE (TYPE_VALUES (type));
4930 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4932 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4937 prev = TREE_VALUE (t);
4946 #define BITARRAY_TEST(ARRAY, INDEX) \
4947 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4948 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4949 #define BITARRAY_SET(ARRAY, INDEX) \
4950 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4951 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4953 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4954 with the case values we have seen, assuming the case expression
4956 SPARSENESS is as determined by all_cases_count.
4958 The time needed is proportional to COUNT, unless
4959 SPARSENESS is 2, in which case quadratic time is needed. */
4962 mark_seen_cases (type, cases_seen, count, sparseness)
4964 unsigned char *cases_seen;
4968 tree next_node_to_try = NULL_TREE;
4969 long next_node_offset = 0;
4971 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4972 tree val = make_node (INTEGER_CST);
4973 TREE_TYPE (val) = type;
4976 else if (sparseness == 2)
4981 /* This less efficient loop is only needed to handle
4982 duplicate case values (multiple enum constants
4983 with the same value). */
4984 TREE_TYPE (val) = TREE_TYPE (root->low);
4985 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4986 t = TREE_CHAIN (t), xlo++)
4988 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4989 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4993 /* Keep going past elements distinctly greater than VAL. */
4994 if (tree_int_cst_lt (val, n->low))
4997 /* or distinctly less than VAL. */
4998 else if (tree_int_cst_lt (n->high, val))
5003 /* We have found a matching range. */
5004 BITARRAY_SET (cases_seen, xlo);
5014 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5015 for (n = root; n; n = n->right)
5017 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5018 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5019 while ( ! tree_int_cst_lt (n->high, val))
5021 /* Calculate (into xlo) the "offset" of the integer (val).
5022 The element with lowest value has offset 0, the next smallest
5023 element has offset 1, etc. */
5025 HOST_WIDE_INT xlo, xhi;
5027 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5029 /* The TYPE_VALUES will be in increasing order, so
5030 starting searching where we last ended. */
5031 t = next_node_to_try;
5032 xlo = next_node_offset;
5038 t = TYPE_VALUES (type);
5041 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5043 next_node_to_try = TREE_CHAIN (t);
5044 next_node_offset = xlo + 1;
5049 if (t == next_node_to_try)
5058 t = TYPE_MIN_VALUE (type);
5060 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5064 add_double (xlo, xhi,
5065 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5069 if (xhi == 0 && xlo >= 0 && xlo < count)
5070 BITARRAY_SET (cases_seen, xlo);
5071 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5073 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5079 /* Called when the index of a switch statement is an enumerated type
5080 and there is no default label.
5082 Checks that all enumeration literals are covered by the case
5083 expressions of a switch. Also, warn if there are any extra
5084 switch cases that are *not* elements of the enumerated type.
5086 If all enumeration literals were covered by the case expressions,
5087 turn one of the expressions into the default expression since it should
5088 not be possible to fall through such a switch. */
5091 check_for_full_enumeration_handling (type)
5094 register struct case_node *n;
5095 register tree chain;
5096 #if 0 /* variable used by 'if 0'ed code below. */
5097 register struct case_node **l;
5101 /* True iff the selector type is a numbered set mode. */
5104 /* The number of possible selector values. */
5107 /* For each possible selector value. a one iff it has been matched
5108 by a case value alternative. */
5109 unsigned char *cases_seen;
5111 /* The allocated size of cases_seen, in chars. */
5117 size = all_cases_count (type, &sparseness);
5118 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5120 if (size > 0 && size < 600000
5121 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5122 this optimization if we don't have enough memory rather than
5123 aborting, as xmalloc would do. */
5124 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5127 tree v = TYPE_VALUES (type);
5129 /* The time complexity of this code is normally O(N), where
5130 N being the number of members in the enumerated type.
5131 However, if type is a ENUMERAL_TYPE whose values do not
5132 increase monotonically, O(N*log(N)) time may be needed. */
5134 mark_seen_cases (type, cases_seen, size, sparseness);
5136 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5138 if (BITARRAY_TEST(cases_seen, i) == 0)
5139 warning ("enumeration value `%s' not handled in switch",
5140 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5146 /* Now we go the other way around; we warn if there are case
5147 expressions that don't correspond to enumerators. This can
5148 occur since C and C++ don't enforce type-checking of
5149 assignments to enumeration variables. */
5151 if (case_stack->data.case_stmt.case_list
5152 && case_stack->data.case_stmt.case_list->left)
5153 case_stack->data.case_stmt.case_list
5154 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5156 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5158 for (chain = TYPE_VALUES (type);
5159 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5160 chain = TREE_CHAIN (chain))
5165 if (TYPE_NAME (type) == 0)
5166 warning ("case value `%ld' not in enumerated type",
5167 (long) TREE_INT_CST_LOW (n->low));
5169 warning ("case value `%ld' not in enumerated type `%s'",
5170 (long) TREE_INT_CST_LOW (n->low),
5171 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5174 : DECL_NAME (TYPE_NAME (type))));
5176 if (!tree_int_cst_equal (n->low, n->high))
5178 for (chain = TYPE_VALUES (type);
5179 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5180 chain = TREE_CHAIN (chain))
5185 if (TYPE_NAME (type) == 0)
5186 warning ("case value `%ld' not in enumerated type",
5187 (long) TREE_INT_CST_LOW (n->high));
5189 warning ("case value `%ld' not in enumerated type `%s'",
5190 (long) TREE_INT_CST_LOW (n->high),
5191 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5194 : DECL_NAME (TYPE_NAME (type))));
5200 /* ??? This optimization is disabled because it causes valid programs to
5201 fail. ANSI C does not guarantee that an expression with enum type
5202 will have a value that is the same as one of the enumeration literals. */
5204 /* If all values were found as case labels, make one of them the default
5205 label. Thus, this switch will never fall through. We arbitrarily pick
5206 the last one to make the default since this is likely the most
5207 efficient choice. */
5211 for (l = &case_stack->data.case_stmt.case_list;
5216 case_stack->data.case_stmt.default_label = (*l)->code_label;
5223 /* Terminate a case (Pascal) or switch (C) statement
5224 in which ORIG_INDEX is the expression to be tested.
5225 Generate the code to test it and jump to the right place. */
5228 expand_end_case (orig_index)
5231 tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval;
5232 rtx default_label = 0;
5233 register struct case_node *n;
5241 register struct nesting *thiscase = case_stack;
5242 tree index_expr, index_type;
5245 /* Don't crash due to previous errors. */
5246 if (thiscase == NULL)
5249 table_label = gen_label_rtx ();
5250 index_expr = thiscase->data.case_stmt.index_expr;
5251 index_type = TREE_TYPE (index_expr);
5252 unsignedp = TREE_UNSIGNED (index_type);
5254 do_pending_stack_adjust ();
5256 /* This might get an spurious warning in the presence of a syntax error;
5257 it could be fixed by moving the call to check_seenlabel after the
5258 check for error_mark_node, and copying the code of check_seenlabel that
5259 deals with case_stack->data.case_stmt.line_number_status /
5260 restore_line_number_status in front of the call to end_cleanup_deferral;
5261 However, this might miss some useful warnings in the presence of
5262 non-syntax errors. */
5265 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5266 if (index_type != error_mark_node)
5268 /* If switch expression was an enumerated type, check that all
5269 enumeration literals are covered by the cases.
5270 No sense trying this if there's a default case, however. */
5272 if (!thiscase->data.case_stmt.default_label
5273 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5274 && TREE_CODE (index_expr) != INTEGER_CST)
5275 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5277 /* If we don't have a default-label, create one here,
5278 after the body of the switch. */
5279 if (thiscase->data.case_stmt.default_label == 0)
5281 thiscase->data.case_stmt.default_label
5282 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5283 expand_label (thiscase->data.case_stmt.default_label);
5285 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5287 before_case = get_last_insn ();
5289 if (thiscase->data.case_stmt.case_list
5290 && thiscase->data.case_stmt.case_list->left)
5291 thiscase->data.case_stmt.case_list
5292 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5294 /* Simplify the case-list before we count it. */
5295 group_case_nodes (thiscase->data.case_stmt.case_list);
5297 /* Get upper and lower bounds of case values.
5298 Also convert all the case values to the index expr's data type. */
5301 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5303 /* Check low and high label values are integers. */
5304 if (TREE_CODE (n->low) != INTEGER_CST)
5306 if (TREE_CODE (n->high) != INTEGER_CST)
5309 n->low = convert (index_type, n->low);
5310 n->high = convert (index_type, n->high);
5312 /* Count the elements and track the largest and smallest
5313 of them (treating them as signed even if they are not). */
5321 if (INT_CST_LT (n->low, minval))
5323 if (INT_CST_LT (maxval, n->high))
5326 /* A range counts double, since it requires two compares. */
5327 if (! tree_int_cst_equal (n->low, n->high))
5331 orig_minval = minval;
5333 /* Compute span of values. */
5335 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5337 end_cleanup_deferral ();
5341 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5343 emit_jump (default_label);
5346 /* If range of values is much bigger than number of values,
5347 make a sequence of conditional branches instead of a dispatch.
5348 If the switch-index is a constant, do it this way
5349 because we can optimize it. */
5351 #ifndef CASE_VALUES_THRESHOLD
5353 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5355 /* If machine does not have a case insn that compares the
5356 bounds, this means extra overhead for dispatch tables
5357 which raises the threshold for using them. */
5358 #define CASE_VALUES_THRESHOLD 5
5359 #endif /* HAVE_casesi */
5360 #endif /* CASE_VALUES_THRESHOLD */
5362 else if (TREE_INT_CST_HIGH (range) != 0
5363 || count < (unsigned int) CASE_VALUES_THRESHOLD
5364 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5366 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5369 || TREE_CODE (index_expr) == INTEGER_CST
5370 /* These will reduce to a constant. */
5371 || (TREE_CODE (index_expr) == CALL_EXPR
5372 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5373 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5374 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5375 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5376 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5378 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5380 /* If the index is a short or char that we do not have
5381 an insn to handle comparisons directly, convert it to
5382 a full integer now, rather than letting each comparison
5383 generate the conversion. */
5385 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5386 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5387 == CODE_FOR_nothing))
5389 enum machine_mode wider_mode;
5390 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5391 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5392 if (cmp_optab->handlers[(int) wider_mode].insn_code
5393 != CODE_FOR_nothing)
5395 index = convert_to_mode (wider_mode, index, unsignedp);
5401 do_pending_stack_adjust ();
5403 index = protect_from_queue (index, 0);
5404 if (GET_CODE (index) == MEM)
5405 index = copy_to_reg (index);
5406 if (GET_CODE (index) == CONST_INT
5407 || TREE_CODE (index_expr) == INTEGER_CST)
5409 /* Make a tree node with the proper constant value
5410 if we don't already have one. */
5411 if (TREE_CODE (index_expr) != INTEGER_CST)
5414 = build_int_2 (INTVAL (index),
5415 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5416 index_expr = convert (index_type, index_expr);
5419 /* For constant index expressions we need only
5420 issue a unconditional branch to the appropriate
5421 target code. The job of removing any unreachable
5422 code is left to the optimisation phase if the
5423 "-O" option is specified. */
5424 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5425 if (! tree_int_cst_lt (index_expr, n->low)
5426 && ! tree_int_cst_lt (n->high, index_expr))
5430 emit_jump (label_rtx (n->code_label));
5432 emit_jump (default_label);
5436 /* If the index expression is not constant we generate
5437 a binary decision tree to select the appropriate
5438 target code. This is done as follows:
5440 The list of cases is rearranged into a binary tree,
5441 nearly optimal assuming equal probability for each case.
5443 The tree is transformed into RTL, eliminating
5444 redundant test conditions at the same time.
5446 If program flow could reach the end of the
5447 decision tree an unconditional jump to the
5448 default code is emitted. */
5451 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5452 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5453 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5455 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5456 default_label, index_type);
5457 emit_jump_if_reachable (default_label);
5466 enum machine_mode index_mode = SImode;
5467 int index_bits = GET_MODE_BITSIZE (index_mode);
5469 enum machine_mode op_mode;
5471 /* Convert the index to SImode. */
5472 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5473 > GET_MODE_BITSIZE (index_mode))
5475 enum machine_mode omode = TYPE_MODE (index_type);
5476 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5478 /* We must handle the endpoints in the original mode. */
5479 index_expr = build (MINUS_EXPR, index_type,
5480 index_expr, minval);
5481 minval = integer_zero_node;
5482 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5483 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5484 omode, 1, 0, default_label);
5485 /* Now we can safely truncate. */
5486 index = convert_to_mode (index_mode, index, 0);
5490 if (TYPE_MODE (index_type) != index_mode)
5492 index_expr = convert (type_for_size (index_bits, 0),
5494 index_type = TREE_TYPE (index_expr);
5497 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5500 index = protect_from_queue (index, 0);
5501 do_pending_stack_adjust ();
5503 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5504 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5506 index = copy_to_mode_reg (op_mode, index);
5508 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5510 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5511 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5513 op1 = copy_to_mode_reg (op_mode, op1);
5515 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5517 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5518 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5520 op2 = copy_to_mode_reg (op_mode, op2);
5522 emit_jump_insn (gen_casesi (index, op1, op2,
5523 table_label, default_label));
5527 #ifdef HAVE_tablejump
5528 if (! win && HAVE_tablejump)
5530 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5531 fold (build (MINUS_EXPR, index_type,
5532 index_expr, minval)));
5533 index_type = TREE_TYPE (index_expr);
5534 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5536 index = protect_from_queue (index, 0);
5537 do_pending_stack_adjust ();
5539 do_tablejump (index, TYPE_MODE (index_type),
5540 expand_expr (range, NULL_RTX, VOIDmode, 0),
5541 table_label, default_label);
5548 /* Get table of labels to jump to, in order of case index. */
5550 ncases = TREE_INT_CST_LOW (range) + 1;
5551 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5552 bzero ((char *) labelvec, ncases * sizeof (rtx));
5554 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5556 register HOST_WIDE_INT i
5557 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5562 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5563 if (i + TREE_INT_CST_LOW (orig_minval)
5564 == TREE_INT_CST_LOW (n->high))
5570 /* Fill in the gaps with the default. */
5571 for (i = 0; i < ncases; i++)
5572 if (labelvec[i] == 0)
5573 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5575 /* Output the table */
5576 emit_label (table_label);
5578 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5579 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5580 gen_rtx_LABEL_REF (Pmode, table_label),
5581 gen_rtvec_v (ncases, labelvec),
5582 const0_rtx, const0_rtx));
5584 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5585 gen_rtvec_v (ncases, labelvec)));
5587 /* If the case insn drops through the table,
5588 after the table we must jump to the default-label.
5589 Otherwise record no drop-through after the table. */
5590 #ifdef CASE_DROPS_THROUGH
5591 emit_jump (default_label);
5597 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5598 reorder_insns (before_case, get_last_insn (),
5599 thiscase->data.case_stmt.start);
5602 end_cleanup_deferral ();
5604 if (thiscase->exit_label)
5605 emit_label (thiscase->exit_label);
5607 POPSTACK (case_stack);
5612 /* Convert the tree NODE into a list linked by the right field, with the left
5613 field zeroed. RIGHT is used for recursion; it is a list to be placed
5614 rightmost in the resulting list. */
5616 static struct case_node *
5617 case_tree2list (node, right)
5618 struct case_node *node, *right;
5620 struct case_node *left;
5623 right = case_tree2list (node->right, right);
5625 node->right = right;
5626 if ((left = node->left))
5629 return case_tree2list (left, node);
5635 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5638 do_jump_if_equal (op1, op2, label, unsignedp)
5639 rtx op1, op2, label;
5642 if (GET_CODE (op1) == CONST_INT
5643 && GET_CODE (op2) == CONST_INT)
5645 if (INTVAL (op1) == INTVAL (op2))
5650 enum machine_mode mode = GET_MODE (op1);
5651 if (mode == VOIDmode)
5652 mode = GET_MODE (op2);
5653 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5658 /* Not all case values are encountered equally. This function
5659 uses a heuristic to weight case labels, in cases where that
5660 looks like a reasonable thing to do.
5662 Right now, all we try to guess is text, and we establish the
5665 chars above space: 16
5674 If we find any cases in the switch that are not either -1 or in the range
5675 of valid ASCII characters, or are control characters other than those
5676 commonly used with "\", don't treat this switch scanning text.
5678 Return 1 if these nodes are suitable for cost estimation, otherwise
5682 estimate_case_costs (node)
5685 tree min_ascii = build_int_2 (-1, -1);
5686 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5690 /* If we haven't already made the cost table, make it now. Note that the
5691 lower bound of the table is -1, not zero. */
5693 if (cost_table == NULL)
5695 cost_table = ((short *) xcalloc (129, sizeof (short))) + 1;
5697 for (i = 0; i < 128; i++)
5701 else if (ISPUNCT (i))
5703 else if (ISCNTRL (i))
5707 cost_table[' '] = 8;
5708 cost_table['\t'] = 4;
5709 cost_table['\0'] = 4;
5710 cost_table['\n'] = 2;
5711 cost_table['\f'] = 1;
5712 cost_table['\v'] = 1;
5713 cost_table['\b'] = 1;
5716 /* See if all the case expressions look like text. It is text if the
5717 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5718 as signed arithmetic since we don't want to ever access cost_table with a
5719 value less than -1. Also check that none of the constants in a range
5720 are strange control characters. */
5722 for (n = node; n; n = n->right)
5724 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5727 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5728 if (cost_table[i] < 0)
5732 /* All interesting values are within the range of interesting
5733 ASCII characters. */
5737 /* Scan an ordered list of case nodes
5738 combining those with consecutive values or ranges.
5740 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5743 group_case_nodes (head)
5746 case_node_ptr node = head;
5750 rtx lb = next_real_insn (label_rtx (node->code_label));
5752 case_node_ptr np = node;
5754 /* Try to group the successors of NODE with NODE. */
5755 while (((np = np->right) != 0)
5756 /* Do they jump to the same place? */
5757 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5758 || (lb != 0 && lb2 != 0
5759 && simplejump_p (lb)
5760 && simplejump_p (lb2)
5761 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5762 SET_SRC (PATTERN (lb2)))))
5763 /* Are their ranges consecutive? */
5764 && tree_int_cst_equal (np->low,
5765 fold (build (PLUS_EXPR,
5766 TREE_TYPE (node->high),
5769 /* An overflow is not consecutive. */
5770 && tree_int_cst_lt (node->high,
5771 fold (build (PLUS_EXPR,
5772 TREE_TYPE (node->high),
5774 integer_one_node))))
5776 node->high = np->high;
5778 /* NP is the first node after NODE which can't be grouped with it.
5779 Delete the nodes in between, and move on to that node. */
5785 /* Take an ordered list of case nodes
5786 and transform them into a near optimal binary tree,
5787 on the assumption that any target code selection value is as
5788 likely as any other.
5790 The transformation is performed by splitting the ordered
5791 list into two equal sections plus a pivot. The parts are
5792 then attached to the pivot as left and right branches. Each
5793 branch is then transformed recursively. */
5796 balance_case_nodes (head, parent)
5797 case_node_ptr *head;
5798 case_node_ptr parent;
5800 register case_node_ptr np;
5808 register case_node_ptr *npp;
5811 /* Count the number of entries on branch. Also count the ranges. */
5815 if (!tree_int_cst_equal (np->low, np->high))
5819 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5823 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5831 /* Split this list if it is long enough for that to help. */
5836 /* Find the place in the list that bisects the list's total cost,
5837 Here I gets half the total cost. */
5842 /* Skip nodes while their cost does not reach that amount. */
5843 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5844 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5845 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5848 npp = &(*npp)->right;
5853 /* Leave this branch lopsided, but optimize left-hand
5854 side and fill in `parent' fields for right-hand side. */
5856 np->parent = parent;
5857 balance_case_nodes (&np->left, np);
5858 for (; np->right; np = np->right)
5859 np->right->parent = np;
5863 /* If there are just three nodes, split at the middle one. */
5865 npp = &(*npp)->right;
5868 /* Find the place in the list that bisects the list's total cost,
5869 where ranges count as 2.
5870 Here I gets half the total cost. */
5871 i = (i + ranges + 1) / 2;
5874 /* Skip nodes while their cost does not reach that amount. */
5875 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5880 npp = &(*npp)->right;
5885 np->parent = parent;
5888 /* Optimize each of the two split parts. */
5889 balance_case_nodes (&np->left, np);
5890 balance_case_nodes (&np->right, np);
5894 /* Else leave this branch as one level,
5895 but fill in `parent' fields. */
5897 np->parent = parent;
5898 for (; np->right; np = np->right)
5899 np->right->parent = np;
5904 /* Search the parent sections of the case node tree
5905 to see if a test for the lower bound of NODE would be redundant.
5906 INDEX_TYPE is the type of the index expression.
5908 The instructions to generate the case decision tree are
5909 output in the same order as nodes are processed so it is
5910 known that if a parent node checks the range of the current
5911 node minus one that the current node is bounded at its lower
5912 span. Thus the test would be redundant. */
5915 node_has_low_bound (node, index_type)
5920 case_node_ptr pnode;
5922 /* If the lower bound of this node is the lowest value in the index type,
5923 we need not test it. */
5925 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5928 /* If this node has a left branch, the value at the left must be less
5929 than that at this node, so it cannot be bounded at the bottom and
5930 we need not bother testing any further. */
5935 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5936 node->low, integer_one_node));
5938 /* If the subtraction above overflowed, we can't verify anything.
5939 Otherwise, look for a parent that tests our value - 1. */
5941 if (! tree_int_cst_lt (low_minus_one, node->low))
5944 for (pnode = node->parent; pnode; pnode = pnode->parent)
5945 if (tree_int_cst_equal (low_minus_one, pnode->high))
5951 /* Search the parent sections of the case node tree
5952 to see if a test for the upper bound of NODE would be redundant.
5953 INDEX_TYPE is the type of the index expression.
5955 The instructions to generate the case decision tree are
5956 output in the same order as nodes are processed so it is
5957 known that if a parent node checks the range of the current
5958 node plus one that the current node is bounded at its upper
5959 span. Thus the test would be redundant. */
5962 node_has_high_bound (node, index_type)
5967 case_node_ptr pnode;
5969 /* If there is no upper bound, obviously no test is needed. */
5971 if (TYPE_MAX_VALUE (index_type) == NULL)
5974 /* If the upper bound of this node is the highest value in the type
5975 of the index expression, we need not test against it. */
5977 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5980 /* If this node has a right branch, the value at the right must be greater
5981 than that at this node, so it cannot be bounded at the top and
5982 we need not bother testing any further. */
5987 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5988 node->high, integer_one_node));
5990 /* If the addition above overflowed, we can't verify anything.
5991 Otherwise, look for a parent that tests our value + 1. */
5993 if (! tree_int_cst_lt (node->high, high_plus_one))
5996 for (pnode = node->parent; pnode; pnode = pnode->parent)
5997 if (tree_int_cst_equal (high_plus_one, pnode->low))
6003 /* Search the parent sections of the
6004 case node tree to see if both tests for the upper and lower
6005 bounds of NODE would be redundant. */
6008 node_is_bounded (node, index_type)
6012 return (node_has_low_bound (node, index_type)
6013 && node_has_high_bound (node, index_type));
6016 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6019 emit_jump_if_reachable (label)
6022 if (GET_CODE (get_last_insn ()) != BARRIER)
6026 /* Emit step-by-step code to select a case for the value of INDEX.
6027 The thus generated decision tree follows the form of the
6028 case-node binary tree NODE, whose nodes represent test conditions.
6029 INDEX_TYPE is the type of the index of the switch.
6031 Care is taken to prune redundant tests from the decision tree
6032 by detecting any boundary conditions already checked by
6033 emitted rtx. (See node_has_high_bound, node_has_low_bound
6034 and node_is_bounded, above.)
6036 Where the test conditions can be shown to be redundant we emit
6037 an unconditional jump to the target code. As a further
6038 optimization, the subordinates of a tree node are examined to
6039 check for bounded nodes. In this case conditional and/or
6040 unconditional jumps as a result of the boundary check for the
6041 current node are arranged to target the subordinates associated
6042 code for out of bound conditions on the current node.
6044 We can assume that when control reaches the code generated here,
6045 the index value has already been compared with the parents
6046 of this node, and determined to be on the same side of each parent
6047 as this node is. Thus, if this node tests for the value 51,
6048 and a parent tested for 52, we don't need to consider
6049 the possibility of a value greater than 51. If another parent
6050 tests for the value 50, then this node need not test anything. */
6053 emit_case_nodes (index, node, default_label, index_type)
6059 /* If INDEX has an unsigned type, we must make unsigned branches. */
6060 int unsignedp = TREE_UNSIGNED (index_type);
6061 typedef rtx rtx_fn ();
6062 enum machine_mode mode = GET_MODE (index);
6064 /* See if our parents have already tested everything for us.
6065 If they have, emit an unconditional jump for this node. */
6066 if (node_is_bounded (node, index_type))
6067 emit_jump (label_rtx (node->code_label));
6069 else if (tree_int_cst_equal (node->low, node->high))
6071 /* Node is single valued. First see if the index expression matches
6072 this node and then check our children, if any. */
6074 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6075 label_rtx (node->code_label), unsignedp);
6077 if (node->right != 0 && node->left != 0)
6079 /* This node has children on both sides.
6080 Dispatch to one side or the other
6081 by comparing the index value with this node's value.
6082 If one subtree is bounded, check that one first,
6083 so we can avoid real branches in the tree. */
6085 if (node_is_bounded (node->right, index_type))
6087 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6089 GT, NULL_RTX, mode, unsignedp, 0,
6090 label_rtx (node->right->code_label));
6091 emit_case_nodes (index, node->left, default_label, index_type);
6094 else if (node_is_bounded (node->left, index_type))
6096 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6098 LT, NULL_RTX, mode, unsignedp, 0,
6099 label_rtx (node->left->code_label));
6100 emit_case_nodes (index, node->right, default_label, index_type);
6105 /* Neither node is bounded. First distinguish the two sides;
6106 then emit the code for one side at a time. */
6109 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6111 /* See if the value is on the right. */
6112 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6114 GT, NULL_RTX, mode, unsignedp, 0,
6115 label_rtx (test_label));
6117 /* Value must be on the left.
6118 Handle the left-hand subtree. */
6119 emit_case_nodes (index, node->left, default_label, index_type);
6120 /* If left-hand subtree does nothing,
6122 emit_jump_if_reachable (default_label);
6124 /* Code branches here for the right-hand subtree. */
6125 expand_label (test_label);
6126 emit_case_nodes (index, node->right, default_label, index_type);
6130 else if (node->right != 0 && node->left == 0)
6132 /* Here we have a right child but no left so we issue conditional
6133 branch to default and process the right child.
6135 Omit the conditional branch to default if we it avoid only one
6136 right child; it costs too much space to save so little time. */
6138 if (node->right->right || node->right->left
6139 || !tree_int_cst_equal (node->right->low, node->right->high))
6141 if (!node_has_low_bound (node, index_type))
6143 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6146 LT, NULL_RTX, mode, unsignedp, 0,
6150 emit_case_nodes (index, node->right, default_label, index_type);
6153 /* We cannot process node->right normally
6154 since we haven't ruled out the numbers less than
6155 this node's value. So handle node->right explicitly. */
6156 do_jump_if_equal (index,
6157 expand_expr (node->right->low, NULL_RTX,
6159 label_rtx (node->right->code_label), unsignedp);
6162 else if (node->right == 0 && node->left != 0)
6164 /* Just one subtree, on the left. */
6166 #if 0 /* The following code and comment were formerly part
6167 of the condition here, but they didn't work
6168 and I don't understand what the idea was. -- rms. */
6169 /* If our "most probable entry" is less probable
6170 than the default label, emit a jump to
6171 the default label using condition codes
6172 already lying around. With no right branch,
6173 a branch-greater-than will get us to the default
6176 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6179 if (node->left->left || node->left->right
6180 || !tree_int_cst_equal (node->left->low, node->left->high))
6182 if (!node_has_high_bound (node, index_type))
6184 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6187 GT, NULL_RTX, mode, unsignedp, 0,
6191 emit_case_nodes (index, node->left, default_label, index_type);
6194 /* We cannot process node->left normally
6195 since we haven't ruled out the numbers less than
6196 this node's value. So handle node->left explicitly. */
6197 do_jump_if_equal (index,
6198 expand_expr (node->left->low, NULL_RTX,
6200 label_rtx (node->left->code_label), unsignedp);
6205 /* Node is a range. These cases are very similar to those for a single
6206 value, except that we do not start by testing whether this node
6207 is the one to branch to. */
6209 if (node->right != 0 && node->left != 0)
6211 /* Node has subtrees on both sides.
6212 If the right-hand subtree is bounded,
6213 test for it first, since we can go straight there.
6214 Otherwise, we need to make a branch in the control structure,
6215 then handle the two subtrees. */
6216 tree test_label = 0;
6219 if (node_is_bounded (node->right, index_type))
6220 /* Right hand node is fully bounded so we can eliminate any
6221 testing and branch directly to the target code. */
6222 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6224 GT, NULL_RTX, mode, unsignedp, 0,
6225 label_rtx (node->right->code_label));
6228 /* Right hand node requires testing.
6229 Branch to a label where we will handle it later. */
6231 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6232 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6234 GT, NULL_RTX, mode, unsignedp, 0,
6235 label_rtx (test_label));
6238 /* Value belongs to this node or to the left-hand subtree. */
6240 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6242 GE, NULL_RTX, mode, unsignedp, 0,
6243 label_rtx (node->code_label));
6245 /* Handle the left-hand subtree. */
6246 emit_case_nodes (index, node->left, default_label, index_type);
6248 /* If right node had to be handled later, do that now. */
6252 /* If the left-hand subtree fell through,
6253 don't let it fall into the right-hand subtree. */
6254 emit_jump_if_reachable (default_label);
6256 expand_label (test_label);
6257 emit_case_nodes (index, node->right, default_label, index_type);
6261 else if (node->right != 0 && node->left == 0)
6263 /* Deal with values to the left of this node,
6264 if they are possible. */
6265 if (!node_has_low_bound (node, index_type))
6267 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6269 LT, NULL_RTX, mode, unsignedp, 0,
6273 /* Value belongs to this node or to the right-hand subtree. */
6275 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6277 LE, NULL_RTX, mode, unsignedp, 0,
6278 label_rtx (node->code_label));
6280 emit_case_nodes (index, node->right, default_label, index_type);
6283 else if (node->right == 0 && node->left != 0)
6285 /* Deal with values to the right of this node,
6286 if they are possible. */
6287 if (!node_has_high_bound (node, index_type))
6289 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6291 GT, NULL_RTX, mode, unsignedp, 0,
6295 /* Value belongs to this node or to the left-hand subtree. */
6297 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6299 GE, NULL_RTX, mode, unsignedp, 0,
6300 label_rtx (node->code_label));
6302 emit_case_nodes (index, node->left, default_label, index_type);
6307 /* Node has no children so we check low and high bounds to remove
6308 redundant tests. Only one of the bounds can exist,
6309 since otherwise this node is bounded--a case tested already. */
6311 if (!node_has_high_bound (node, index_type))
6313 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6315 GT, NULL_RTX, mode, unsignedp, 0,
6319 if (!node_has_low_bound (node, index_type))
6321 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6323 LT, NULL_RTX, mode, unsignedp, 0,
6327 emit_jump (label_rtx (node->code_label));
6332 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6333 so that the debugging info will be correct for the unrolled loop. */
6336 find_loop_tree_blocks ()
6338 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6342 unroll_block_trees ()
6344 tree block = DECL_INITIAL (current_function_decl);
6346 reorder_blocks (block, get_insns ());