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 /* When we insert instructions after the last unconditional cleanup,
3234 we don't adjust last_insn. That means that a later add_insn will
3235 clobber the instructions we've just added. The easiest way to
3236 fix this is to just insert another instruction here, so that the
3237 instructions inserted after the last unconditional cleanup are
3238 never the last instruction. */
3239 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3240 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3243 && !(block_stack->data.block.cleanups == NULL_TREE
3244 && block_stack->data.block.outer_cleanups == NULL_TREE))
3245 thisblock->data.block.outer_cleanups
3246 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3247 block_stack->data.block.outer_cleanups);
3249 thisblock->data.block.outer_cleanups = 0;
3250 thisblock->data.block.label_chain = 0;
3251 thisblock->data.block.innermost_stack_block = stack_block_stack;
3252 thisblock->data.block.first_insn = note;
3253 thisblock->data.block.block_start_count = ++current_block_start_count;
3254 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3255 block_stack = thisblock;
3256 nesting_stack = thisblock;
3258 /* Make a new level for allocating stack slots. */
3262 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3263 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3264 expand_expr are made. After we end the region, we know that all
3265 space for all temporaries that were created by TARGET_EXPRs will be
3266 destroyed and their space freed for reuse. */
3269 expand_start_target_temps ()
3271 /* This is so that even if the result is preserved, the space
3272 allocated will be freed, as we know that it is no longer in use. */
3275 /* Start a new binding layer that will keep track of all cleanup
3276 actions to be performed. */
3277 expand_start_bindings (2);
3279 target_temp_slot_level = temp_slot_level;
3283 expand_end_target_temps ()
3285 expand_end_bindings (NULL_TREE, 0, 0);
3287 /* This is so that even if the result is preserved, the space
3288 allocated will be freed, as we know that it is no longer in use. */
3292 /* Mark top block of block_stack as an implicit binding for an
3293 exception region. This is used to prevent infinite recursion when
3294 ending a binding with expand_end_bindings. It is only ever called
3295 by expand_eh_region_start, as that it the only way to create a
3296 block stack for a exception region. */
3299 mark_block_as_eh_region ()
3301 block_stack->data.block.exception_region = 1;
3302 if (block_stack->next
3303 && block_stack->next->data.block.conditional_code)
3305 block_stack->data.block.conditional_code
3306 = block_stack->next->data.block.conditional_code;
3307 block_stack->data.block.last_unconditional_cleanup
3308 = block_stack->next->data.block.last_unconditional_cleanup;
3309 block_stack->data.block.cleanup_ptr
3310 = block_stack->next->data.block.cleanup_ptr;
3314 /* True if we are currently emitting insns in an area of output code
3315 that is controlled by a conditional expression. This is used by
3316 the cleanup handling code to generate conditional cleanup actions. */
3319 conditional_context ()
3321 return block_stack && block_stack->data.block.conditional_code;
3324 /* Mark top block of block_stack as not for an implicit binding for an
3325 exception region. This is only ever done by expand_eh_region_end
3326 to let expand_end_bindings know that it is being called explicitly
3327 to end the binding layer for just the binding layer associated with
3328 the exception region, otherwise expand_end_bindings would try and
3329 end all implicit binding layers for exceptions regions, and then
3330 one normal binding layer. */
3333 mark_block_as_not_eh_region ()
3335 block_stack->data.block.exception_region = 0;
3338 /* True if the top block of block_stack was marked as for an exception
3339 region by mark_block_as_eh_region. */
3344 return (current_function && block_stack
3345 && block_stack->data.block.exception_region);
3348 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3349 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3353 remember_end_note (block)
3354 register tree block;
3356 BLOCK_END_NOTE (block) = last_block_end_note;
3357 last_block_end_note = NULL_RTX;
3360 /* Emit a handler label for a nonlocal goto handler.
3361 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3364 expand_nl_handler_label (slot, before_insn)
3365 rtx slot, before_insn;
3368 rtx handler_label = gen_label_rtx ();
3370 /* Don't let jump_optimize delete the handler. */
3371 LABEL_PRESERVE_P (handler_label) = 1;
3374 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3375 insns = get_insns ();
3377 emit_insns_before (insns, before_insn);
3379 emit_label (handler_label);
3381 return handler_label;
3384 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3387 expand_nl_goto_receiver ()
3389 #ifdef HAVE_nonlocal_goto
3390 if (! HAVE_nonlocal_goto)
3392 /* First adjust our frame pointer to its actual value. It was
3393 previously set to the start of the virtual area corresponding to
3394 the stacked variables when we branched here and now needs to be
3395 adjusted to the actual hardware fp value.
3397 Assignments are to virtual registers are converted by
3398 instantiate_virtual_regs into the corresponding assignment
3399 to the underlying register (fp in this case) that makes
3400 the original assignment true.
3401 So the following insn will actually be
3402 decrementing fp by STARTING_FRAME_OFFSET. */
3403 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3405 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3406 if (fixed_regs[ARG_POINTER_REGNUM])
3408 #ifdef ELIMINABLE_REGS
3409 /* If the argument pointer can be eliminated in favor of the
3410 frame pointer, we don't need to restore it. We assume here
3411 that if such an elimination is present, it can always be used.
3412 This is the case on all known machines; if we don't make this
3413 assumption, we do unnecessary saving on many machines. */
3414 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3417 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3418 if (elim_regs[i].from == ARG_POINTER_REGNUM
3419 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3422 if (i == sizeof elim_regs / sizeof elim_regs [0])
3425 /* Now restore our arg pointer from the address at which it
3426 was saved in our stack frame.
3427 If there hasn't be space allocated for it yet, make
3429 if (arg_pointer_save_area == 0)
3430 arg_pointer_save_area
3431 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3432 emit_move_insn (virtual_incoming_args_rtx,
3433 /* We need a pseudo here, or else
3434 instantiate_virtual_regs_1 complains. */
3435 copy_to_reg (arg_pointer_save_area));
3440 #ifdef HAVE_nonlocal_goto_receiver
3441 if (HAVE_nonlocal_goto_receiver)
3442 emit_insn (gen_nonlocal_goto_receiver ());
3446 /* Make handlers for nonlocal gotos taking place in the function calls in
3450 expand_nl_goto_receivers (thisblock)
3451 struct nesting *thisblock;
3454 rtx afterward = gen_label_rtx ();
3459 /* Record the handler address in the stack slot for that purpose,
3460 during this block, saving and restoring the outer value. */
3461 if (thisblock->next != 0)
3462 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3464 rtx save_receiver = gen_reg_rtx (Pmode);
3465 emit_move_insn (XEXP (slot, 0), save_receiver);
3468 emit_move_insn (save_receiver, XEXP (slot, 0));
3469 insns = get_insns ();
3471 emit_insns_before (insns, thisblock->data.block.first_insn);
3474 /* Jump around the handlers; they run only when specially invoked. */
3475 emit_jump (afterward);
3477 /* Make a separate handler for each label. */
3478 link = nonlocal_labels;
3479 slot = nonlocal_goto_handler_slots;
3480 label_list = NULL_RTX;
3481 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3482 /* Skip any labels we shouldn't be able to jump to from here,
3483 we generate one special handler for all of them below which just calls
3485 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3488 lab = expand_nl_handler_label (XEXP (slot, 0),
3489 thisblock->data.block.first_insn);
3490 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3492 expand_nl_goto_receiver ();
3494 /* Jump to the "real" nonlocal label. */
3495 expand_goto (TREE_VALUE (link));
3498 /* A second pass over all nonlocal labels; this time we handle those
3499 we should not be able to jump to at this point. */
3500 link = nonlocal_labels;
3501 slot = nonlocal_goto_handler_slots;
3503 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3504 if (DECL_TOO_LATE (TREE_VALUE (link)))
3507 lab = expand_nl_handler_label (XEXP (slot, 0),
3508 thisblock->data.block.first_insn);
3509 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3515 expand_nl_goto_receiver ();
3516 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3521 nonlocal_goto_handler_labels = label_list;
3522 emit_label (afterward);
3525 /* Warn about any unused VARS (which may contain nodes other than
3526 VAR_DECLs, but such nodes are ignored). The nodes are connected
3527 via the TREE_CHAIN field. */
3530 warn_about_unused_variables (vars)
3536 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3537 if (TREE_CODE (decl) == VAR_DECL
3538 && ! TREE_USED (decl)
3539 && ! DECL_IN_SYSTEM_HEADER (decl)
3540 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3541 warning_with_decl (decl, "unused variable `%s'");
3544 /* Generate RTL code to terminate a binding contour.
3546 VARS is the chain of VAR_DECL nodes for the variables bound in this
3547 contour. There may actually be other nodes in this chain, but any
3548 nodes other than VAR_DECLS are ignored.
3550 MARK_ENDS is nonzero if we should put a note at the beginning
3551 and end of this binding contour.
3553 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3554 (That is true automatically if the contour has a saved stack level.) */
3557 expand_end_bindings (vars, mark_ends, dont_jump_in)
3562 register struct nesting *thisblock;
3565 while (block_stack->data.block.exception_region)
3567 /* Because we don't need or want a new temporary level and
3568 because we didn't create one in expand_eh_region_start,
3569 create a fake one now to avoid removing one in
3570 expand_end_bindings. */
3573 block_stack->data.block.exception_region = 0;
3575 expand_end_bindings (NULL_TREE, 0, 0);
3578 /* Since expand_eh_region_start does an expand_start_bindings, we
3579 have to first end all the bindings that were created by
3580 expand_eh_region_start. */
3582 thisblock = block_stack;
3584 /* If any of the variables in this scope were not used, warn the
3586 warn_about_unused_variables (vars);
3588 if (thisblock->exit_label)
3590 do_pending_stack_adjust ();
3591 emit_label (thisblock->exit_label);
3594 /* If necessary, make handlers for nonlocal gotos taking
3595 place in the function calls in this block. */
3596 if (function_call_count != thisblock->data.block.n_function_calls
3598 /* Make handler for outermost block
3599 if there were any nonlocal gotos to this function. */
3600 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3601 /* Make handler for inner block if it has something
3602 special to do when you jump out of it. */
3603 : (thisblock->data.block.cleanups != 0
3604 || thisblock->data.block.stack_level != 0)))
3605 expand_nl_goto_receivers (thisblock);
3607 /* Don't allow jumping into a block that has a stack level.
3608 Cleanups are allowed, though. */
3610 || thisblock->data.block.stack_level != 0)
3612 struct label_chain *chain;
3614 /* Any labels in this block are no longer valid to go to.
3615 Mark them to cause an error message. */
3616 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3618 DECL_TOO_LATE (chain->label) = 1;
3619 /* If any goto without a fixup came to this label,
3620 that must be an error, because gotos without fixups
3621 come from outside all saved stack-levels. */
3622 if (TREE_ADDRESSABLE (chain->label))
3623 error_with_decl (chain->label,
3624 "label `%s' used before containing binding contour");
3628 /* Restore stack level in effect before the block
3629 (only if variable-size objects allocated). */
3630 /* Perform any cleanups associated with the block. */
3632 if (thisblock->data.block.stack_level != 0
3633 || thisblock->data.block.cleanups != 0)
3635 /* Only clean up here if this point can actually be reached. */
3636 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3638 /* Don't let cleanups affect ({...}) constructs. */
3639 int old_expr_stmts_for_value = expr_stmts_for_value;
3640 rtx old_last_expr_value = last_expr_value;
3641 tree old_last_expr_type = last_expr_type;
3642 expr_stmts_for_value = 0;
3644 /* Do the cleanups. */
3645 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3647 do_pending_stack_adjust ();
3649 expr_stmts_for_value = old_expr_stmts_for_value;
3650 last_expr_value = old_last_expr_value;
3651 last_expr_type = old_last_expr_type;
3653 /* Restore the stack level. */
3655 if (reachable && thisblock->data.block.stack_level != 0)
3657 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3658 thisblock->data.block.stack_level, NULL_RTX);
3659 if (nonlocal_goto_handler_slots != 0)
3660 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3664 /* Any gotos out of this block must also do these things.
3665 Also report any gotos with fixups that came to labels in this
3667 fixup_gotos (thisblock,
3668 thisblock->data.block.stack_level,
3669 thisblock->data.block.cleanups,
3670 thisblock->data.block.first_insn,
3674 /* Mark the beginning and end of the scope if requested.
3675 We do this now, after running cleanups on the variables
3676 just going out of scope, so they are in scope for their cleanups. */
3679 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3681 /* Get rid of the beginning-mark if we don't make an end-mark. */
3682 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3684 /* If doing stupid register allocation, make sure lives of all
3685 register variables declared here extend thru end of scope. */
3688 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3689 if (TREE_CODE (decl) == VAR_DECL && DECL_RTL (decl))
3690 use_variable (DECL_RTL (decl));
3692 /* Restore the temporary level of TARGET_EXPRs. */
3693 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3695 /* Restore block_stack level for containing block. */
3697 stack_block_stack = thisblock->data.block.innermost_stack_block;
3698 POPSTACK (block_stack);
3700 /* Pop the stack slot nesting and free any slots at this level. */
3704 /* Generate RTL for the automatic variable declaration DECL.
3705 (Other kinds of declarations are simply ignored if seen here.) */
3711 struct nesting *thisblock;
3714 type = TREE_TYPE (decl);
3716 /* Only automatic variables need any expansion done.
3717 Static and external variables, and external functions,
3718 will be handled by `assemble_variable' (called from finish_decl).
3719 TYPE_DECL and CONST_DECL require nothing.
3720 PARM_DECLs are handled in `assign_parms'. */
3722 if (TREE_CODE (decl) != VAR_DECL)
3724 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3727 thisblock = block_stack;
3729 /* Create the RTL representation for the variable. */
3731 if (type == error_mark_node)
3732 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3733 else if (DECL_SIZE (decl) == 0)
3734 /* Variable with incomplete type. */
3736 if (DECL_INITIAL (decl) == 0)
3737 /* Error message was already done; now avoid a crash. */
3738 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3740 /* An initializer is going to decide the size of this array.
3741 Until we know the size, represent its address with a reg. */
3742 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3743 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3745 else if (DECL_MODE (decl) != BLKmode
3746 /* If -ffloat-store, don't put explicit float vars
3748 && !(flag_float_store
3749 && TREE_CODE (type) == REAL_TYPE)
3750 && ! TREE_THIS_VOLATILE (decl)
3751 && ! TREE_ADDRESSABLE (decl)
3752 && (DECL_REGISTER (decl) || ! obey_regdecls)
3753 /* if -fcheck-memory-usage, check all variables. */
3754 && ! current_function_check_memory_usage)
3756 /* Automatic variable that can go in a register. */
3757 int unsignedp = TREE_UNSIGNED (type);
3758 enum machine_mode reg_mode
3759 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3761 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3762 mark_user_reg (DECL_RTL (decl));
3764 if (POINTER_TYPE_P (type))
3765 mark_reg_pointer (DECL_RTL (decl),
3766 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3770 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3771 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3772 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3773 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3774 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3776 /* Variable of fixed size that goes on the stack. */
3780 /* If we previously made RTL for this decl, it must be an array
3781 whose size was determined by the initializer.
3782 The old address was a register; set that register now
3783 to the proper address. */
3784 if (DECL_RTL (decl) != 0)
3786 if (GET_CODE (DECL_RTL (decl)) != MEM
3787 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3789 oldaddr = XEXP (DECL_RTL (decl), 0);
3792 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3793 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3794 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3796 /* Set alignment we actually gave this decl. */
3797 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3798 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3802 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3803 if (addr != oldaddr)
3804 emit_move_insn (oldaddr, addr);
3807 /* If this is a memory ref that contains aggregate components,
3808 mark it as such for cse and loop optimize. */
3809 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3810 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3812 /* If this is in memory because of -ffloat-store,
3813 set the volatile bit, to prevent optimizations from
3814 undoing the effects. */
3815 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3816 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3819 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3822 /* Dynamic-size object: must push space on the stack. */
3826 /* Record the stack pointer on entry to block, if have
3827 not already done so. */
3828 if (thisblock->data.block.stack_level == 0)
3830 do_pending_stack_adjust ();
3831 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3832 &thisblock->data.block.stack_level,
3833 thisblock->data.block.first_insn);
3834 stack_block_stack = thisblock;
3837 /* Compute the variable's size, in bytes. */
3838 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3840 size_int (BITS_PER_UNIT)),
3841 NULL_RTX, VOIDmode, 0);
3844 /* Allocate space on the stack for the variable. Note that
3845 DECL_ALIGN says how the variable is to be aligned and we
3846 cannot use it to conclude anything about the alignment of
3848 address = allocate_dynamic_stack_space (size, NULL_RTX,
3849 TYPE_ALIGN (TREE_TYPE (decl)));
3851 /* Reference the variable indirect through that rtx. */
3852 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3854 /* If this is a memory ref that contains aggregate components,
3855 mark it as such for cse and loop optimize. */
3856 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3857 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3859 /* Indicate the alignment we actually gave this variable. */
3860 #ifdef STACK_BOUNDARY
3861 DECL_ALIGN (decl) = STACK_BOUNDARY;
3863 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3867 if (TREE_THIS_VOLATILE (decl))
3868 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3869 #if 0 /* A variable is not necessarily unchanging
3870 just because it is const. RTX_UNCHANGING_P
3871 means no change in the function,
3872 not merely no change in the variable's scope.
3873 It is correct to set RTX_UNCHANGING_P if the variable's scope
3874 is the whole function. There's no convenient way to test that. */
3875 if (TREE_READONLY (decl))
3876 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3879 /* If doing stupid register allocation, make sure life of any
3880 register variable starts here, at the start of its scope. */
3883 use_variable (DECL_RTL (decl));
3888 /* Emit code to perform the initialization of a declaration DECL. */
3891 expand_decl_init (decl)
3894 int was_used = TREE_USED (decl);
3896 /* If this is a CONST_DECL, we don't have to generate any code, but
3897 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3898 to be set while in the obstack containing the constant. If we don't
3899 do this, we can lose if we have functions nested three deep and the middle
3900 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3901 the innermost function is the first to expand that STRING_CST. */
3902 if (TREE_CODE (decl) == CONST_DECL)
3904 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3905 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3906 EXPAND_INITIALIZER);
3910 if (TREE_STATIC (decl))
3913 /* Compute and store the initial value now. */
3915 if (DECL_INITIAL (decl) == error_mark_node)
3917 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3919 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3920 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3921 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3925 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3927 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3928 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3932 /* Don't let the initialization count as "using" the variable. */
3933 TREE_USED (decl) = was_used;
3935 /* Free any temporaries we made while initializing the decl. */
3936 preserve_temp_slots (NULL_RTX);
3940 /* CLEANUP is an expression to be executed at exit from this binding contour;
3941 for example, in C++, it might call the destructor for this variable.
3943 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3944 CLEANUP multiple times, and have the correct semantics. This
3945 happens in exception handling, for gotos, returns, breaks that
3946 leave the current scope.
3948 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3949 that is not associated with any particular variable. */
3952 expand_decl_cleanup (decl, cleanup)
3955 struct nesting *thisblock;
3957 /* Error if we are not in any block. */
3958 if (current_function == 0 || block_stack == 0)
3961 thisblock = block_stack;
3963 /* Record the cleanup if there is one. */
3969 tree *cleanups = &thisblock->data.block.cleanups;
3970 int cond_context = conditional_context ();
3974 rtx flag = gen_reg_rtx (word_mode);
3979 emit_move_insn (flag, const0_rtx);
3980 set_flag_0 = get_insns ();
3983 thisblock->data.block.last_unconditional_cleanup
3984 = emit_insns_after (set_flag_0,
3985 thisblock->data.block.last_unconditional_cleanup);
3987 emit_move_insn (flag, const1_rtx);
3989 /* All cleanups must be on the function_obstack. */
3990 push_obstacks_nochange ();
3991 resume_temporary_allocation ();
3993 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3994 DECL_RTL (cond) = flag;
3996 /* Conditionalize the cleanup. */
3997 cleanup = build (COND_EXPR, void_type_node,
3998 truthvalue_conversion (cond),
3999 cleanup, integer_zero_node);
4000 cleanup = fold (cleanup);
4004 cleanups = thisblock->data.block.cleanup_ptr;
4007 /* All cleanups must be on the function_obstack. */
4008 push_obstacks_nochange ();
4009 resume_temporary_allocation ();
4010 cleanup = unsave_expr (cleanup);
4013 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4016 /* If this block has a cleanup, it belongs in stack_block_stack. */
4017 stack_block_stack = thisblock;
4024 /* If this was optimized so that there is no exception region for the
4025 cleanup, then mark the TREE_LIST node, so that we can later tell
4026 if we need to call expand_eh_region_end. */
4027 if (! using_eh_for_cleanups_p
4028 || expand_eh_region_start_tree (decl, cleanup))
4029 TREE_ADDRESSABLE (t) = 1;
4030 /* If that started a new EH region, we're in a new block. */
4031 thisblock = block_stack;
4038 thisblock->data.block.last_unconditional_cleanup
4039 = emit_insns_after (seq,
4040 thisblock->data.block.last_unconditional_cleanup);
4044 thisblock->data.block.last_unconditional_cleanup
4046 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4052 /* Like expand_decl_cleanup, but suppress generating an exception handler
4053 to perform the cleanup. */
4056 expand_decl_cleanup_no_eh (decl, cleanup)
4059 int save_eh = using_eh_for_cleanups_p;
4062 using_eh_for_cleanups_p = 0;
4063 result = expand_decl_cleanup (decl, cleanup);
4064 using_eh_for_cleanups_p = save_eh;
4069 /* Arrange for the top element of the dynamic cleanup chain to be
4070 popped if we exit the current binding contour. DECL is the
4071 associated declaration, if any, otherwise NULL_TREE. If the
4072 current contour is left via an exception, then __sjthrow will pop
4073 the top element off the dynamic cleanup chain. The code that
4074 avoids doing the action we push into the cleanup chain in the
4075 exceptional case is contained in expand_cleanups.
4077 This routine is only used by expand_eh_region_start, and that is
4078 the only way in which an exception region should be started. This
4079 routine is only used when using the setjmp/longjmp codegen method
4080 for exception handling. */
4083 expand_dcc_cleanup (decl)
4086 struct nesting *thisblock;
4089 /* Error if we are not in any block. */
4090 if (current_function == 0 || block_stack == 0)
4092 thisblock = block_stack;
4094 /* Record the cleanup for the dynamic handler chain. */
4096 /* All cleanups must be on the function_obstack. */
4097 push_obstacks_nochange ();
4098 resume_temporary_allocation ();
4099 cleanup = make_node (POPDCC_EXPR);
4102 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4103 thisblock->data.block.cleanups
4104 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4106 /* If this block has a cleanup, it belongs in stack_block_stack. */
4107 stack_block_stack = thisblock;
4111 /* Arrange for the top element of the dynamic handler chain to be
4112 popped if we exit the current binding contour. DECL is the
4113 associated declaration, if any, otherwise NULL_TREE. If the current
4114 contour is left via an exception, then __sjthrow will pop the top
4115 element off the dynamic handler chain. The code that avoids doing
4116 the action we push into the handler chain in the exceptional case
4117 is contained in expand_cleanups.
4119 This routine is only used by expand_eh_region_start, and that is
4120 the only way in which an exception region should be started. This
4121 routine is only used when using the setjmp/longjmp codegen method
4122 for exception handling. */
4125 expand_dhc_cleanup (decl)
4128 struct nesting *thisblock;
4131 /* Error if we are not in any block. */
4132 if (current_function == 0 || block_stack == 0)
4134 thisblock = block_stack;
4136 /* Record the cleanup for the dynamic handler chain. */
4138 /* All cleanups must be on the function_obstack. */
4139 push_obstacks_nochange ();
4140 resume_temporary_allocation ();
4141 cleanup = make_node (POPDHC_EXPR);
4144 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4145 thisblock->data.block.cleanups
4146 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4148 /* If this block has a cleanup, it belongs in stack_block_stack. */
4149 stack_block_stack = thisblock;
4153 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4154 DECL_ELTS is the list of elements that belong to DECL's type.
4155 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4158 expand_anon_union_decl (decl, cleanup, decl_elts)
4159 tree decl, cleanup, decl_elts;
4161 struct nesting *thisblock = current_function == 0 ? 0 : block_stack;
4165 expand_decl_cleanup (decl, cleanup);
4166 x = DECL_RTL (decl);
4170 tree decl_elt = TREE_VALUE (decl_elts);
4171 tree cleanup_elt = TREE_PURPOSE (decl_elts);
4172 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4174 /* Propagate the union's alignment to the elements. */
4175 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4177 /* If the element has BLKmode and the union doesn't, the union is
4178 aligned such that the element doesn't need to have BLKmode, so
4179 change the element's mode to the appropriate one for its size. */
4180 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4181 DECL_MODE (decl_elt) = mode
4182 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4185 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4186 instead create a new MEM rtx with the proper mode. */
4187 if (GET_CODE (x) == MEM)
4189 if (mode == GET_MODE (x))
4190 DECL_RTL (decl_elt) = x;
4193 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4194 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4195 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4198 else if (GET_CODE (x) == REG)
4200 if (mode == GET_MODE (x))
4201 DECL_RTL (decl_elt) = x;
4203 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4208 /* Record the cleanup if there is one. */
4211 thisblock->data.block.cleanups
4212 = temp_tree_cons (decl_elt, cleanup_elt,
4213 thisblock->data.block.cleanups);
4215 decl_elts = TREE_CHAIN (decl_elts);
4219 /* Expand a list of cleanups LIST.
4220 Elements may be expressions or may be nested lists.
4222 If DONT_DO is nonnull, then any list-element
4223 whose TREE_PURPOSE matches DONT_DO is omitted.
4224 This is sometimes used to avoid a cleanup associated with
4225 a value that is being returned out of the scope.
4227 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4228 goto and handle protection regions specially in that case.
4230 If REACHABLE, we emit code, otherwise just inform the exception handling
4231 code about this finalization. */
4234 expand_cleanups (list, dont_do, in_fixup, reachable)
4241 for (tail = list; tail; tail = TREE_CHAIN (tail))
4242 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4244 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4245 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4250 tree cleanup = TREE_VALUE (tail);
4252 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4253 if (TREE_CODE (cleanup) != POPDHC_EXPR
4254 && TREE_CODE (cleanup) != POPDCC_EXPR
4255 /* See expand_eh_region_start_tree for this case. */
4256 && ! TREE_ADDRESSABLE (tail))
4258 cleanup = protect_with_terminate (cleanup);
4259 expand_eh_region_end (cleanup);
4265 /* Cleanups may be run multiple times. For example,
4266 when exiting a binding contour, we expand the
4267 cleanups associated with that contour. When a goto
4268 within that binding contour has a target outside that
4269 contour, it will expand all cleanups from its scope to
4270 the target. Though the cleanups are expanded multiple
4271 times, the control paths are non-overlapping so the
4272 cleanups will not be executed twice. */
4274 /* We may need to protect fixups with rethrow regions. */
4275 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4278 expand_fixup_region_start ();
4280 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4282 expand_fixup_region_end (TREE_VALUE (tail));
4289 /* Mark when the context we are emitting RTL for as a conditional
4290 context, so that any cleanup actions we register with
4291 expand_decl_init will be properly conditionalized when those
4292 cleanup actions are later performed. Must be called before any
4293 expression (tree) is expanded that is within a conditional context. */
4296 start_cleanup_deferral ()
4298 /* block_stack can be NULL if we are inside the parameter list. It is
4299 OK to do nothing, because cleanups aren't possible here. */
4301 ++block_stack->data.block.conditional_code;
4304 /* Mark the end of a conditional region of code. Because cleanup
4305 deferrals may be nested, we may still be in a conditional region
4306 after we end the currently deferred cleanups, only after we end all
4307 deferred cleanups, are we back in unconditional code. */
4310 end_cleanup_deferral ()
4312 /* block_stack can be NULL if we are inside the parameter list. It is
4313 OK to do nothing, because cleanups aren't possible here. */
4315 --block_stack->data.block.conditional_code;
4318 /* Move all cleanups from the current block_stack
4319 to the containing block_stack, where they are assumed to
4320 have been created. If anything can cause a temporary to
4321 be created, but not expanded for more than one level of
4322 block_stacks, then this code will have to change. */
4327 struct nesting *block = block_stack;
4328 struct nesting *outer = block->next;
4330 outer->data.block.cleanups
4331 = chainon (block->data.block.cleanups,
4332 outer->data.block.cleanups);
4333 block->data.block.cleanups = 0;
4337 last_cleanup_this_contour ()
4339 if (block_stack == 0)
4342 return block_stack->data.block.cleanups;
4345 /* Return 1 if there are any pending cleanups at this point.
4346 If THIS_CONTOUR is nonzero, check the current contour as well.
4347 Otherwise, look only at the contours that enclose this one. */
4350 any_pending_cleanups (this_contour)
4353 struct nesting *block;
4355 if (current_function == NULL || current_function->stmt == NULL
4356 || block_stack == 0)
4359 if (this_contour && block_stack->data.block.cleanups != NULL)
4361 if (block_stack->data.block.cleanups == 0
4362 && block_stack->data.block.outer_cleanups == 0)
4365 for (block = block_stack->next; block; block = block->next)
4366 if (block->data.block.cleanups != 0)
4372 /* Enter a case (Pascal) or switch (C) statement.
4373 Push a block onto case_stack and nesting_stack
4374 to accumulate the case-labels that are seen
4375 and to record the labels generated for the statement.
4377 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4378 Otherwise, this construct is transparent for `exit_something'.
4380 EXPR is the index-expression to be dispatched on.
4381 TYPE is its nominal type. We could simply convert EXPR to this type,
4382 but instead we take short cuts. */
4385 expand_start_case (exit_flag, expr, type, printname)
4389 const char *printname;
4391 register struct nesting *thiscase = ALLOC_NESTING ();
4393 /* Make an entry on case_stack for the case we are entering. */
4395 thiscase->next = case_stack;
4396 thiscase->all = nesting_stack;
4397 thiscase->depth = ++nesting_depth;
4398 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4399 thiscase->data.case_stmt.case_list = 0;
4400 thiscase->data.case_stmt.index_expr = expr;
4401 thiscase->data.case_stmt.nominal_type = type;
4402 thiscase->data.case_stmt.default_label = 0;
4403 thiscase->data.case_stmt.num_ranges = 0;
4404 thiscase->data.case_stmt.printname = printname;
4405 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4406 case_stack = thiscase;
4407 nesting_stack = thiscase;
4409 do_pending_stack_adjust ();
4411 /* Make sure case_stmt.start points to something that won't
4412 need any transformation before expand_end_case. */
4413 if (GET_CODE (get_last_insn ()) != NOTE)
4414 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4416 thiscase->data.case_stmt.start = get_last_insn ();
4418 start_cleanup_deferral ();
4422 /* Start a "dummy case statement" within which case labels are invalid
4423 and are not connected to any larger real case statement.
4424 This can be used if you don't want to let a case statement jump
4425 into the middle of certain kinds of constructs. */
4428 expand_start_case_dummy ()
4430 register struct nesting *thiscase = ALLOC_NESTING ();
4432 /* Make an entry on case_stack for the dummy. */
4434 thiscase->next = case_stack;
4435 thiscase->all = nesting_stack;
4436 thiscase->depth = ++nesting_depth;
4437 thiscase->exit_label = 0;
4438 thiscase->data.case_stmt.case_list = 0;
4439 thiscase->data.case_stmt.start = 0;
4440 thiscase->data.case_stmt.nominal_type = 0;
4441 thiscase->data.case_stmt.default_label = 0;
4442 thiscase->data.case_stmt.num_ranges = 0;
4443 case_stack = thiscase;
4444 nesting_stack = thiscase;
4445 start_cleanup_deferral ();
4448 /* End a dummy case statement. */
4451 expand_end_case_dummy ()
4453 end_cleanup_deferral ();
4454 POPSTACK (case_stack);
4457 /* Return the data type of the index-expression
4458 of the innermost case statement, or null if none. */
4461 case_index_expr_type ()
4464 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4471 /* If this is the first label, warn if any insns have been emitted. */
4472 if (case_stack->data.case_stmt.line_number_status >= 0)
4476 restore_line_number_status
4477 (case_stack->data.case_stmt.line_number_status);
4478 case_stack->data.case_stmt.line_number_status = -1;
4480 for (insn = case_stack->data.case_stmt.start;
4482 insn = NEXT_INSN (insn))
4484 if (GET_CODE (insn) == CODE_LABEL)
4486 if (GET_CODE (insn) != NOTE
4487 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4490 insn = PREV_INSN (insn);
4491 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4493 /* If insn is zero, then there must have been a syntax error. */
4495 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4496 NOTE_LINE_NUMBER(insn),
4497 "unreachable code at beginning of %s",
4498 case_stack->data.case_stmt.printname);
4505 /* Accumulate one case or default label inside a case or switch statement.
4506 VALUE is the value of the case (a null pointer, for a default label).
4507 The function CONVERTER, when applied to arguments T and V,
4508 converts the value V to the type T.
4510 If not currently inside a case or switch statement, return 1 and do
4511 nothing. The caller will print a language-specific error message.
4512 If VALUE is a duplicate or overlaps, return 2 and do nothing
4513 except store the (first) duplicate node in *DUPLICATE.
4514 If VALUE is out of range, return 3 and do nothing.
4515 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4516 Return 0 on success.
4518 Extended to handle range statements. */
4521 pushcase (value, converter, label, duplicate)
4522 register tree value;
4523 tree (*converter) PROTO((tree, tree));
4524 register tree label;
4530 /* Fail if not inside a real case statement. */
4531 if (! (case_stack && case_stack->data.case_stmt.start))
4534 if (stack_block_stack
4535 && stack_block_stack->depth > case_stack->depth)
4538 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4539 nominal_type = case_stack->data.case_stmt.nominal_type;
4541 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4542 if (index_type == error_mark_node)
4545 /* Convert VALUE to the type in which the comparisons are nominally done. */
4547 value = (*converter) (nominal_type, value);
4551 /* Fail if this value is out of range for the actual type of the index
4552 (which may be narrower than NOMINAL_TYPE). */
4553 if (value != 0 && ! int_fits_type_p (value, index_type))
4556 /* Fail if this is a duplicate or overlaps another entry. */
4559 if (case_stack->data.case_stmt.default_label != 0)
4561 *duplicate = case_stack->data.case_stmt.default_label;
4564 case_stack->data.case_stmt.default_label = label;
4567 return add_case_node (value, value, label, duplicate);
4569 expand_label (label);
4573 /* Like pushcase but this case applies to all values between VALUE1 and
4574 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4575 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4576 starts at VALUE1 and ends at the highest value of the index type.
4577 If both are NULL, this case applies to all values.
4579 The return value is the same as that of pushcase but there is one
4580 additional error code: 4 means the specified range was empty. */
4583 pushcase_range (value1, value2, converter, label, duplicate)
4584 register tree value1, value2;
4585 tree (*converter) PROTO((tree, tree));
4586 register tree label;
4592 /* Fail if not inside a real case statement. */
4593 if (! (case_stack && case_stack->data.case_stmt.start))
4596 if (stack_block_stack
4597 && stack_block_stack->depth > case_stack->depth)
4600 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4601 nominal_type = case_stack->data.case_stmt.nominal_type;
4603 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4604 if (index_type == error_mark_node)
4609 /* Convert VALUEs to type in which the comparisons are nominally done
4610 and replace any unspecified value with the corresponding bound. */
4612 value1 = TYPE_MIN_VALUE (index_type);
4614 value2 = TYPE_MAX_VALUE (index_type);
4616 /* Fail if the range is empty. Do this before any conversion since
4617 we want to allow out-of-range empty ranges. */
4618 if (value2 && tree_int_cst_lt (value2, value1))
4621 value1 = (*converter) (nominal_type, value1);
4623 /* If the max was unbounded, use the max of the nominal_type we are
4624 converting to. Do this after the < check above to suppress false
4627 value2 = TYPE_MAX_VALUE (nominal_type);
4628 value2 = (*converter) (nominal_type, value2);
4630 /* Fail if these values are out of range. */
4631 if (TREE_CONSTANT_OVERFLOW (value1)
4632 || ! int_fits_type_p (value1, index_type))
4635 if (TREE_CONSTANT_OVERFLOW (value2)
4636 || ! int_fits_type_p (value2, index_type))
4639 return add_case_node (value1, value2, label, duplicate);
4642 /* Do the actual insertion of a case label for pushcase and pushcase_range
4643 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4644 slowdown for large switch statements. */
4647 add_case_node (low, high, label, duplicate)
4652 struct case_node *p, **q, *r;
4654 q = &case_stack->data.case_stmt.case_list;
4661 /* Keep going past elements distinctly greater than HIGH. */
4662 if (tree_int_cst_lt (high, p->low))
4665 /* or distinctly less than LOW. */
4666 else if (tree_int_cst_lt (p->high, low))
4671 /* We have an overlap; this is an error. */
4672 *duplicate = p->code_label;
4677 /* Add this label to the chain, and succeed.
4678 Copy LOW, HIGH so they are on temporary rather than momentary
4679 obstack and will thus survive till the end of the case statement. */
4681 r = (struct case_node *) oballoc (sizeof (struct case_node));
4682 r->low = copy_node (low);
4684 /* If the bounds are equal, turn this into the one-value case. */
4686 if (tree_int_cst_equal (low, high))
4690 r->high = copy_node (high);
4691 case_stack->data.case_stmt.num_ranges++;
4694 r->code_label = label;
4695 expand_label (label);
4705 struct case_node *s;
4711 if (! (b = p->balance))
4712 /* Growth propagation from left side. */
4719 if ((p->left = s = r->right))
4728 if ((r->parent = s))
4736 case_stack->data.case_stmt.case_list = r;
4739 /* r->balance == +1 */
4744 struct case_node *t = r->right;
4746 if ((p->left = s = t->right))
4750 if ((r->right = s = t->left))
4764 if ((t->parent = s))
4772 case_stack->data.case_stmt.case_list = t;
4779 /* p->balance == +1; growth of left side balances the node. */
4789 if (! (b = p->balance))
4790 /* Growth propagation from right side. */
4798 if ((p->right = s = r->left))
4806 if ((r->parent = s))
4815 case_stack->data.case_stmt.case_list = r;
4819 /* r->balance == -1 */
4823 struct case_node *t = r->left;
4825 if ((p->right = s = t->left))
4830 if ((r->left = s = t->right))
4844 if ((t->parent = s))
4853 case_stack->data.case_stmt.case_list = t;
4859 /* p->balance == -1; growth of right side balances the node. */
4873 /* Returns the number of possible values of TYPE.
4874 Returns -1 if the number is unknown or variable.
4875 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4876 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4877 do not increase monotonically (there may be duplicates);
4878 to 1 if the values increase monotonically, but not always by 1;
4879 otherwise sets it to 0. */
4882 all_cases_count (type, spareness)
4886 HOST_WIDE_INT count;
4889 switch (TREE_CODE (type))
4896 count = 1 << BITS_PER_UNIT;
4900 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4901 || TYPE_MAX_VALUE (type) == NULL
4902 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4907 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4908 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4909 but with overflow checking. */
4910 tree mint = TYPE_MIN_VALUE (type);
4911 tree maxt = TYPE_MAX_VALUE (type);
4912 HOST_WIDE_INT lo, hi;
4913 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4915 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4917 add_double (lo, hi, 1, 0, &lo, &hi);
4918 if (hi != 0 || lo < 0)
4925 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4927 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4928 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4929 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4930 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4934 if (*spareness == 1)
4936 tree prev = TREE_VALUE (TYPE_VALUES (type));
4937 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4939 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4944 prev = TREE_VALUE (t);
4953 #define BITARRAY_TEST(ARRAY, INDEX) \
4954 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4955 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4956 #define BITARRAY_SET(ARRAY, INDEX) \
4957 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4958 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4960 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4961 with the case values we have seen, assuming the case expression
4963 SPARSENESS is as determined by all_cases_count.
4965 The time needed is proportional to COUNT, unless
4966 SPARSENESS is 2, in which case quadratic time is needed. */
4969 mark_seen_cases (type, cases_seen, count, sparseness)
4971 unsigned char *cases_seen;
4975 tree next_node_to_try = NULL_TREE;
4976 long next_node_offset = 0;
4978 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4979 tree val = make_node (INTEGER_CST);
4980 TREE_TYPE (val) = type;
4983 else if (sparseness == 2)
4988 /* This less efficient loop is only needed to handle
4989 duplicate case values (multiple enum constants
4990 with the same value). */
4991 TREE_TYPE (val) = TREE_TYPE (root->low);
4992 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4993 t = TREE_CHAIN (t), xlo++)
4995 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4996 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5000 /* Keep going past elements distinctly greater than VAL. */
5001 if (tree_int_cst_lt (val, n->low))
5004 /* or distinctly less than VAL. */
5005 else if (tree_int_cst_lt (n->high, val))
5010 /* We have found a matching range. */
5011 BITARRAY_SET (cases_seen, xlo);
5021 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5022 for (n = root; n; n = n->right)
5024 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5025 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5026 while ( ! tree_int_cst_lt (n->high, val))
5028 /* Calculate (into xlo) the "offset" of the integer (val).
5029 The element with lowest value has offset 0, the next smallest
5030 element has offset 1, etc. */
5032 HOST_WIDE_INT xlo, xhi;
5034 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5036 /* The TYPE_VALUES will be in increasing order, so
5037 starting searching where we last ended. */
5038 t = next_node_to_try;
5039 xlo = next_node_offset;
5045 t = TYPE_VALUES (type);
5048 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5050 next_node_to_try = TREE_CHAIN (t);
5051 next_node_offset = xlo + 1;
5056 if (t == next_node_to_try)
5065 t = TYPE_MIN_VALUE (type);
5067 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5071 add_double (xlo, xhi,
5072 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5076 if (xhi == 0 && xlo >= 0 && xlo < count)
5077 BITARRAY_SET (cases_seen, xlo);
5078 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5080 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5086 /* Called when the index of a switch statement is an enumerated type
5087 and there is no default label.
5089 Checks that all enumeration literals are covered by the case
5090 expressions of a switch. Also, warn if there are any extra
5091 switch cases that are *not* elements of the enumerated type.
5093 If all enumeration literals were covered by the case expressions,
5094 turn one of the expressions into the default expression since it should
5095 not be possible to fall through such a switch. */
5098 check_for_full_enumeration_handling (type)
5101 register struct case_node *n;
5102 register tree chain;
5103 #if 0 /* variable used by 'if 0'ed code below. */
5104 register struct case_node **l;
5108 /* True iff the selector type is a numbered set mode. */
5111 /* The number of possible selector values. */
5114 /* For each possible selector value. a one iff it has been matched
5115 by a case value alternative. */
5116 unsigned char *cases_seen;
5118 /* The allocated size of cases_seen, in chars. */
5124 size = all_cases_count (type, &sparseness);
5125 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5127 if (size > 0 && size < 600000
5128 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5129 this optimization if we don't have enough memory rather than
5130 aborting, as xmalloc would do. */
5131 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5134 tree v = TYPE_VALUES (type);
5136 /* The time complexity of this code is normally O(N), where
5137 N being the number of members in the enumerated type.
5138 However, if type is a ENUMERAL_TYPE whose values do not
5139 increase monotonically, O(N*log(N)) time may be needed. */
5141 mark_seen_cases (type, cases_seen, size, sparseness);
5143 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5145 if (BITARRAY_TEST(cases_seen, i) == 0)
5146 warning ("enumeration value `%s' not handled in switch",
5147 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5153 /* Now we go the other way around; we warn if there are case
5154 expressions that don't correspond to enumerators. This can
5155 occur since C and C++ don't enforce type-checking of
5156 assignments to enumeration variables. */
5158 if (case_stack->data.case_stmt.case_list
5159 && case_stack->data.case_stmt.case_list->left)
5160 case_stack->data.case_stmt.case_list
5161 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5163 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5165 for (chain = TYPE_VALUES (type);
5166 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5167 chain = TREE_CHAIN (chain))
5172 if (TYPE_NAME (type) == 0)
5173 warning ("case value `%ld' not in enumerated type",
5174 (long) TREE_INT_CST_LOW (n->low));
5176 warning ("case value `%ld' not in enumerated type `%s'",
5177 (long) TREE_INT_CST_LOW (n->low),
5178 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5181 : DECL_NAME (TYPE_NAME (type))));
5183 if (!tree_int_cst_equal (n->low, n->high))
5185 for (chain = TYPE_VALUES (type);
5186 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5187 chain = TREE_CHAIN (chain))
5192 if (TYPE_NAME (type) == 0)
5193 warning ("case value `%ld' not in enumerated type",
5194 (long) TREE_INT_CST_LOW (n->high));
5196 warning ("case value `%ld' not in enumerated type `%s'",
5197 (long) TREE_INT_CST_LOW (n->high),
5198 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5201 : DECL_NAME (TYPE_NAME (type))));
5207 /* ??? This optimization is disabled because it causes valid programs to
5208 fail. ANSI C does not guarantee that an expression with enum type
5209 will have a value that is the same as one of the enumeration literals. */
5211 /* If all values were found as case labels, make one of them the default
5212 label. Thus, this switch will never fall through. We arbitrarily pick
5213 the last one to make the default since this is likely the most
5214 efficient choice. */
5218 for (l = &case_stack->data.case_stmt.case_list;
5223 case_stack->data.case_stmt.default_label = (*l)->code_label;
5230 /* Terminate a case (Pascal) or switch (C) statement
5231 in which ORIG_INDEX is the expression to be tested.
5232 Generate the code to test it and jump to the right place. */
5235 expand_end_case (orig_index)
5238 tree minval = NULL_TREE, maxval = NULL_TREE, range, orig_minval;
5239 rtx default_label = 0;
5240 register struct case_node *n;
5248 register struct nesting *thiscase = case_stack;
5249 tree index_expr, index_type;
5252 /* Don't crash due to previous errors. */
5253 if (thiscase == NULL)
5256 table_label = gen_label_rtx ();
5257 index_expr = thiscase->data.case_stmt.index_expr;
5258 index_type = TREE_TYPE (index_expr);
5259 unsignedp = TREE_UNSIGNED (index_type);
5261 do_pending_stack_adjust ();
5263 /* This might get an spurious warning in the presence of a syntax error;
5264 it could be fixed by moving the call to check_seenlabel after the
5265 check for error_mark_node, and copying the code of check_seenlabel that
5266 deals with case_stack->data.case_stmt.line_number_status /
5267 restore_line_number_status in front of the call to end_cleanup_deferral;
5268 However, this might miss some useful warnings in the presence of
5269 non-syntax errors. */
5272 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5273 if (index_type != error_mark_node)
5275 /* If switch expression was an enumerated type, check that all
5276 enumeration literals are covered by the cases.
5277 No sense trying this if there's a default case, however. */
5279 if (!thiscase->data.case_stmt.default_label
5280 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5281 && TREE_CODE (index_expr) != INTEGER_CST)
5282 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5284 /* If we don't have a default-label, create one here,
5285 after the body of the switch. */
5286 if (thiscase->data.case_stmt.default_label == 0)
5288 thiscase->data.case_stmt.default_label
5289 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5290 expand_label (thiscase->data.case_stmt.default_label);
5292 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5294 before_case = get_last_insn ();
5296 if (thiscase->data.case_stmt.case_list
5297 && thiscase->data.case_stmt.case_list->left)
5298 thiscase->data.case_stmt.case_list
5299 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5301 /* Simplify the case-list before we count it. */
5302 group_case_nodes (thiscase->data.case_stmt.case_list);
5304 /* Get upper and lower bounds of case values.
5305 Also convert all the case values to the index expr's data type. */
5308 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5310 /* Check low and high label values are integers. */
5311 if (TREE_CODE (n->low) != INTEGER_CST)
5313 if (TREE_CODE (n->high) != INTEGER_CST)
5316 n->low = convert (index_type, n->low);
5317 n->high = convert (index_type, n->high);
5319 /* Count the elements and track the largest and smallest
5320 of them (treating them as signed even if they are not). */
5328 if (INT_CST_LT (n->low, minval))
5330 if (INT_CST_LT (maxval, n->high))
5333 /* A range counts double, since it requires two compares. */
5334 if (! tree_int_cst_equal (n->low, n->high))
5338 orig_minval = minval;
5340 /* Compute span of values. */
5342 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5344 end_cleanup_deferral ();
5348 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5350 emit_jump (default_label);
5353 /* If range of values is much bigger than number of values,
5354 make a sequence of conditional branches instead of a dispatch.
5355 If the switch-index is a constant, do it this way
5356 because we can optimize it. */
5358 #ifndef CASE_VALUES_THRESHOLD
5360 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5362 /* If machine does not have a case insn that compares the
5363 bounds, this means extra overhead for dispatch tables
5364 which raises the threshold for using them. */
5365 #define CASE_VALUES_THRESHOLD 5
5366 #endif /* HAVE_casesi */
5367 #endif /* CASE_VALUES_THRESHOLD */
5369 else if (TREE_INT_CST_HIGH (range) != 0
5370 || count < (unsigned int) CASE_VALUES_THRESHOLD
5371 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5373 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5376 || TREE_CODE (index_expr) == INTEGER_CST
5377 /* These will reduce to a constant. */
5378 || (TREE_CODE (index_expr) == CALL_EXPR
5379 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5380 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5381 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5382 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5383 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5385 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5387 /* If the index is a short or char that we do not have
5388 an insn to handle comparisons directly, convert it to
5389 a full integer now, rather than letting each comparison
5390 generate the conversion. */
5392 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5393 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5394 == CODE_FOR_nothing))
5396 enum machine_mode wider_mode;
5397 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5398 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5399 if (cmp_optab->handlers[(int) wider_mode].insn_code
5400 != CODE_FOR_nothing)
5402 index = convert_to_mode (wider_mode, index, unsignedp);
5408 do_pending_stack_adjust ();
5410 index = protect_from_queue (index, 0);
5411 if (GET_CODE (index) == MEM)
5412 index = copy_to_reg (index);
5413 if (GET_CODE (index) == CONST_INT
5414 || TREE_CODE (index_expr) == INTEGER_CST)
5416 /* Make a tree node with the proper constant value
5417 if we don't already have one. */
5418 if (TREE_CODE (index_expr) != INTEGER_CST)
5421 = build_int_2 (INTVAL (index),
5422 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5423 index_expr = convert (index_type, index_expr);
5426 /* For constant index expressions we need only
5427 issue a unconditional branch to the appropriate
5428 target code. The job of removing any unreachable
5429 code is left to the optimisation phase if the
5430 "-O" option is specified. */
5431 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5432 if (! tree_int_cst_lt (index_expr, n->low)
5433 && ! tree_int_cst_lt (n->high, index_expr))
5437 emit_jump (label_rtx (n->code_label));
5439 emit_jump (default_label);
5443 /* If the index expression is not constant we generate
5444 a binary decision tree to select the appropriate
5445 target code. This is done as follows:
5447 The list of cases is rearranged into a binary tree,
5448 nearly optimal assuming equal probability for each case.
5450 The tree is transformed into RTL, eliminating
5451 redundant test conditions at the same time.
5453 If program flow could reach the end of the
5454 decision tree an unconditional jump to the
5455 default code is emitted. */
5458 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5459 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5460 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5462 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5463 default_label, index_type);
5464 emit_jump_if_reachable (default_label);
5473 enum machine_mode index_mode = SImode;
5474 int index_bits = GET_MODE_BITSIZE (index_mode);
5476 enum machine_mode op_mode;
5478 /* Convert the index to SImode. */
5479 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5480 > GET_MODE_BITSIZE (index_mode))
5482 enum machine_mode omode = TYPE_MODE (index_type);
5483 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5485 /* We must handle the endpoints in the original mode. */
5486 index_expr = build (MINUS_EXPR, index_type,
5487 index_expr, minval);
5488 minval = integer_zero_node;
5489 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5490 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5491 omode, 1, 0, default_label);
5492 /* Now we can safely truncate. */
5493 index = convert_to_mode (index_mode, index, 0);
5497 if (TYPE_MODE (index_type) != index_mode)
5499 index_expr = convert (type_for_size (index_bits, 0),
5501 index_type = TREE_TYPE (index_expr);
5504 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5507 index = protect_from_queue (index, 0);
5508 do_pending_stack_adjust ();
5510 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5511 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5513 index = copy_to_mode_reg (op_mode, index);
5515 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5517 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5518 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5520 op1 = copy_to_mode_reg (op_mode, op1);
5522 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5524 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5525 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5527 op2 = copy_to_mode_reg (op_mode, op2);
5529 emit_jump_insn (gen_casesi (index, op1, op2,
5530 table_label, default_label));
5534 #ifdef HAVE_tablejump
5535 if (! win && HAVE_tablejump)
5537 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5538 fold (build (MINUS_EXPR, index_type,
5539 index_expr, minval)));
5540 index_type = TREE_TYPE (index_expr);
5541 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5543 index = protect_from_queue (index, 0);
5544 do_pending_stack_adjust ();
5546 do_tablejump (index, TYPE_MODE (index_type),
5547 expand_expr (range, NULL_RTX, VOIDmode, 0),
5548 table_label, default_label);
5555 /* Get table of labels to jump to, in order of case index. */
5557 ncases = TREE_INT_CST_LOW (range) + 1;
5558 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5559 bzero ((char *) labelvec, ncases * sizeof (rtx));
5561 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5563 register HOST_WIDE_INT i
5564 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5569 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5570 if (i + TREE_INT_CST_LOW (orig_minval)
5571 == TREE_INT_CST_LOW (n->high))
5577 /* Fill in the gaps with the default. */
5578 for (i = 0; i < ncases; i++)
5579 if (labelvec[i] == 0)
5580 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5582 /* Output the table */
5583 emit_label (table_label);
5585 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5586 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5587 gen_rtx_LABEL_REF (Pmode, table_label),
5588 gen_rtvec_v (ncases, labelvec),
5589 const0_rtx, const0_rtx));
5591 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5592 gen_rtvec_v (ncases, labelvec)));
5594 /* If the case insn drops through the table,
5595 after the table we must jump to the default-label.
5596 Otherwise record no drop-through after the table. */
5597 #ifdef CASE_DROPS_THROUGH
5598 emit_jump (default_label);
5604 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5605 reorder_insns (before_case, get_last_insn (),
5606 thiscase->data.case_stmt.start);
5609 end_cleanup_deferral ();
5611 if (thiscase->exit_label)
5612 emit_label (thiscase->exit_label);
5614 POPSTACK (case_stack);
5619 /* Convert the tree NODE into a list linked by the right field, with the left
5620 field zeroed. RIGHT is used for recursion; it is a list to be placed
5621 rightmost in the resulting list. */
5623 static struct case_node *
5624 case_tree2list (node, right)
5625 struct case_node *node, *right;
5627 struct case_node *left;
5630 right = case_tree2list (node->right, right);
5632 node->right = right;
5633 if ((left = node->left))
5636 return case_tree2list (left, node);
5642 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5645 do_jump_if_equal (op1, op2, label, unsignedp)
5646 rtx op1, op2, label;
5649 if (GET_CODE (op1) == CONST_INT
5650 && GET_CODE (op2) == CONST_INT)
5652 if (INTVAL (op1) == INTVAL (op2))
5657 enum machine_mode mode = GET_MODE (op1);
5658 if (mode == VOIDmode)
5659 mode = GET_MODE (op2);
5660 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5665 /* Not all case values are encountered equally. This function
5666 uses a heuristic to weight case labels, in cases where that
5667 looks like a reasonable thing to do.
5669 Right now, all we try to guess is text, and we establish the
5672 chars above space: 16
5681 If we find any cases in the switch that are not either -1 or in the range
5682 of valid ASCII characters, or are control characters other than those
5683 commonly used with "\", don't treat this switch scanning text.
5685 Return 1 if these nodes are suitable for cost estimation, otherwise
5689 estimate_case_costs (node)
5692 tree min_ascii = build_int_2 (-1, -1);
5693 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5697 /* If we haven't already made the cost table, make it now. Note that the
5698 lower bound of the table is -1, not zero. */
5700 if (cost_table == NULL)
5702 cost_table = ((short *) xcalloc (129, sizeof (short))) + 1;
5704 for (i = 0; i < 128; i++)
5708 else if (ISPUNCT (i))
5710 else if (ISCNTRL (i))
5714 cost_table[' '] = 8;
5715 cost_table['\t'] = 4;
5716 cost_table['\0'] = 4;
5717 cost_table['\n'] = 2;
5718 cost_table['\f'] = 1;
5719 cost_table['\v'] = 1;
5720 cost_table['\b'] = 1;
5723 /* See if all the case expressions look like text. It is text if the
5724 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5725 as signed arithmetic since we don't want to ever access cost_table with a
5726 value less than -1. Also check that none of the constants in a range
5727 are strange control characters. */
5729 for (n = node; n; n = n->right)
5731 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5734 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5735 if (cost_table[i] < 0)
5739 /* All interesting values are within the range of interesting
5740 ASCII characters. */
5744 /* Scan an ordered list of case nodes
5745 combining those with consecutive values or ranges.
5747 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5750 group_case_nodes (head)
5753 case_node_ptr node = head;
5757 rtx lb = next_real_insn (label_rtx (node->code_label));
5759 case_node_ptr np = node;
5761 /* Try to group the successors of NODE with NODE. */
5762 while (((np = np->right) != 0)
5763 /* Do they jump to the same place? */
5764 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5765 || (lb != 0 && lb2 != 0
5766 && simplejump_p (lb)
5767 && simplejump_p (lb2)
5768 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5769 SET_SRC (PATTERN (lb2)))))
5770 /* Are their ranges consecutive? */
5771 && tree_int_cst_equal (np->low,
5772 fold (build (PLUS_EXPR,
5773 TREE_TYPE (node->high),
5776 /* An overflow is not consecutive. */
5777 && tree_int_cst_lt (node->high,
5778 fold (build (PLUS_EXPR,
5779 TREE_TYPE (node->high),
5781 integer_one_node))))
5783 node->high = np->high;
5785 /* NP is the first node after NODE which can't be grouped with it.
5786 Delete the nodes in between, and move on to that node. */
5792 /* Take an ordered list of case nodes
5793 and transform them into a near optimal binary tree,
5794 on the assumption that any target code selection value is as
5795 likely as any other.
5797 The transformation is performed by splitting the ordered
5798 list into two equal sections plus a pivot. The parts are
5799 then attached to the pivot as left and right branches. Each
5800 branch is then transformed recursively. */
5803 balance_case_nodes (head, parent)
5804 case_node_ptr *head;
5805 case_node_ptr parent;
5807 register case_node_ptr np;
5815 register case_node_ptr *npp;
5818 /* Count the number of entries on branch. Also count the ranges. */
5822 if (!tree_int_cst_equal (np->low, np->high))
5826 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5830 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5838 /* Split this list if it is long enough for that to help. */
5843 /* Find the place in the list that bisects the list's total cost,
5844 Here I gets half the total cost. */
5849 /* Skip nodes while their cost does not reach that amount. */
5850 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5851 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5852 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5855 npp = &(*npp)->right;
5860 /* Leave this branch lopsided, but optimize left-hand
5861 side and fill in `parent' fields for right-hand side. */
5863 np->parent = parent;
5864 balance_case_nodes (&np->left, np);
5865 for (; np->right; np = np->right)
5866 np->right->parent = np;
5870 /* If there are just three nodes, split at the middle one. */
5872 npp = &(*npp)->right;
5875 /* Find the place in the list that bisects the list's total cost,
5876 where ranges count as 2.
5877 Here I gets half the total cost. */
5878 i = (i + ranges + 1) / 2;
5881 /* Skip nodes while their cost does not reach that amount. */
5882 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5887 npp = &(*npp)->right;
5892 np->parent = parent;
5895 /* Optimize each of the two split parts. */
5896 balance_case_nodes (&np->left, np);
5897 balance_case_nodes (&np->right, np);
5901 /* Else leave this branch as one level,
5902 but fill in `parent' fields. */
5904 np->parent = parent;
5905 for (; np->right; np = np->right)
5906 np->right->parent = np;
5911 /* Search the parent sections of the case node tree
5912 to see if a test for the lower bound of NODE would be redundant.
5913 INDEX_TYPE is the type of the index expression.
5915 The instructions to generate the case decision tree are
5916 output in the same order as nodes are processed so it is
5917 known that if a parent node checks the range of the current
5918 node minus one that the current node is bounded at its lower
5919 span. Thus the test would be redundant. */
5922 node_has_low_bound (node, index_type)
5927 case_node_ptr pnode;
5929 /* If the lower bound of this node is the lowest value in the index type,
5930 we need not test it. */
5932 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5935 /* If this node has a left branch, the value at the left must be less
5936 than that at this node, so it cannot be bounded at the bottom and
5937 we need not bother testing any further. */
5942 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5943 node->low, integer_one_node));
5945 /* If the subtraction above overflowed, we can't verify anything.
5946 Otherwise, look for a parent that tests our value - 1. */
5948 if (! tree_int_cst_lt (low_minus_one, node->low))
5951 for (pnode = node->parent; pnode; pnode = pnode->parent)
5952 if (tree_int_cst_equal (low_minus_one, pnode->high))
5958 /* Search the parent sections of the case node tree
5959 to see if a test for the upper bound of NODE would be redundant.
5960 INDEX_TYPE is the type of the index expression.
5962 The instructions to generate the case decision tree are
5963 output in the same order as nodes are processed so it is
5964 known that if a parent node checks the range of the current
5965 node plus one that the current node is bounded at its upper
5966 span. Thus the test would be redundant. */
5969 node_has_high_bound (node, index_type)
5974 case_node_ptr pnode;
5976 /* If there is no upper bound, obviously no test is needed. */
5978 if (TYPE_MAX_VALUE (index_type) == NULL)
5981 /* If the upper bound of this node is the highest value in the type
5982 of the index expression, we need not test against it. */
5984 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5987 /* If this node has a right branch, the value at the right must be greater
5988 than that at this node, so it cannot be bounded at the top and
5989 we need not bother testing any further. */
5994 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5995 node->high, integer_one_node));
5997 /* If the addition above overflowed, we can't verify anything.
5998 Otherwise, look for a parent that tests our value + 1. */
6000 if (! tree_int_cst_lt (node->high, high_plus_one))
6003 for (pnode = node->parent; pnode; pnode = pnode->parent)
6004 if (tree_int_cst_equal (high_plus_one, pnode->low))
6010 /* Search the parent sections of the
6011 case node tree to see if both tests for the upper and lower
6012 bounds of NODE would be redundant. */
6015 node_is_bounded (node, index_type)
6019 return (node_has_low_bound (node, index_type)
6020 && node_has_high_bound (node, index_type));
6023 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6026 emit_jump_if_reachable (label)
6029 if (GET_CODE (get_last_insn ()) != BARRIER)
6033 /* Emit step-by-step code to select a case for the value of INDEX.
6034 The thus generated decision tree follows the form of the
6035 case-node binary tree NODE, whose nodes represent test conditions.
6036 INDEX_TYPE is the type of the index of the switch.
6038 Care is taken to prune redundant tests from the decision tree
6039 by detecting any boundary conditions already checked by
6040 emitted rtx. (See node_has_high_bound, node_has_low_bound
6041 and node_is_bounded, above.)
6043 Where the test conditions can be shown to be redundant we emit
6044 an unconditional jump to the target code. As a further
6045 optimization, the subordinates of a tree node are examined to
6046 check for bounded nodes. In this case conditional and/or
6047 unconditional jumps as a result of the boundary check for the
6048 current node are arranged to target the subordinates associated
6049 code for out of bound conditions on the current node.
6051 We can assume that when control reaches the code generated here,
6052 the index value has already been compared with the parents
6053 of this node, and determined to be on the same side of each parent
6054 as this node is. Thus, if this node tests for the value 51,
6055 and a parent tested for 52, we don't need to consider
6056 the possibility of a value greater than 51. If another parent
6057 tests for the value 50, then this node need not test anything. */
6060 emit_case_nodes (index, node, default_label, index_type)
6066 /* If INDEX has an unsigned type, we must make unsigned branches. */
6067 int unsignedp = TREE_UNSIGNED (index_type);
6068 typedef rtx rtx_fn ();
6069 enum machine_mode mode = GET_MODE (index);
6071 /* See if our parents have already tested everything for us.
6072 If they have, emit an unconditional jump for this node. */
6073 if (node_is_bounded (node, index_type))
6074 emit_jump (label_rtx (node->code_label));
6076 else if (tree_int_cst_equal (node->low, node->high))
6078 /* Node is single valued. First see if the index expression matches
6079 this node and then check our children, if any. */
6081 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6082 label_rtx (node->code_label), unsignedp);
6084 if (node->right != 0 && node->left != 0)
6086 /* This node has children on both sides.
6087 Dispatch to one side or the other
6088 by comparing the index value with this node's value.
6089 If one subtree is bounded, check that one first,
6090 so we can avoid real branches in the tree. */
6092 if (node_is_bounded (node->right, index_type))
6094 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6096 GT, NULL_RTX, mode, unsignedp, 0,
6097 label_rtx (node->right->code_label));
6098 emit_case_nodes (index, node->left, default_label, index_type);
6101 else if (node_is_bounded (node->left, index_type))
6103 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6105 LT, NULL_RTX, mode, unsignedp, 0,
6106 label_rtx (node->left->code_label));
6107 emit_case_nodes (index, node->right, default_label, index_type);
6112 /* Neither node is bounded. First distinguish the two sides;
6113 then emit the code for one side at a time. */
6116 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6118 /* See if the value is on the right. */
6119 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6121 GT, NULL_RTX, mode, unsignedp, 0,
6122 label_rtx (test_label));
6124 /* Value must be on the left.
6125 Handle the left-hand subtree. */
6126 emit_case_nodes (index, node->left, default_label, index_type);
6127 /* If left-hand subtree does nothing,
6129 emit_jump_if_reachable (default_label);
6131 /* Code branches here for the right-hand subtree. */
6132 expand_label (test_label);
6133 emit_case_nodes (index, node->right, default_label, index_type);
6137 else if (node->right != 0 && node->left == 0)
6139 /* Here we have a right child but no left so we issue conditional
6140 branch to default and process the right child.
6142 Omit the conditional branch to default if we it avoid only one
6143 right child; it costs too much space to save so little time. */
6145 if (node->right->right || node->right->left
6146 || !tree_int_cst_equal (node->right->low, node->right->high))
6148 if (!node_has_low_bound (node, index_type))
6150 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6153 LT, NULL_RTX, mode, unsignedp, 0,
6157 emit_case_nodes (index, node->right, default_label, index_type);
6160 /* We cannot process node->right normally
6161 since we haven't ruled out the numbers less than
6162 this node's value. So handle node->right explicitly. */
6163 do_jump_if_equal (index,
6164 expand_expr (node->right->low, NULL_RTX,
6166 label_rtx (node->right->code_label), unsignedp);
6169 else if (node->right == 0 && node->left != 0)
6171 /* Just one subtree, on the left. */
6173 #if 0 /* The following code and comment were formerly part
6174 of the condition here, but they didn't work
6175 and I don't understand what the idea was. -- rms. */
6176 /* If our "most probable entry" is less probable
6177 than the default label, emit a jump to
6178 the default label using condition codes
6179 already lying around. With no right branch,
6180 a branch-greater-than will get us to the default
6183 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6186 if (node->left->left || node->left->right
6187 || !tree_int_cst_equal (node->left->low, node->left->high))
6189 if (!node_has_high_bound (node, index_type))
6191 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6194 GT, NULL_RTX, mode, unsignedp, 0,
6198 emit_case_nodes (index, node->left, default_label, index_type);
6201 /* We cannot process node->left normally
6202 since we haven't ruled out the numbers less than
6203 this node's value. So handle node->left explicitly. */
6204 do_jump_if_equal (index,
6205 expand_expr (node->left->low, NULL_RTX,
6207 label_rtx (node->left->code_label), unsignedp);
6212 /* Node is a range. These cases are very similar to those for a single
6213 value, except that we do not start by testing whether this node
6214 is the one to branch to. */
6216 if (node->right != 0 && node->left != 0)
6218 /* Node has subtrees on both sides.
6219 If the right-hand subtree is bounded,
6220 test for it first, since we can go straight there.
6221 Otherwise, we need to make a branch in the control structure,
6222 then handle the two subtrees. */
6223 tree test_label = 0;
6226 if (node_is_bounded (node->right, index_type))
6227 /* Right hand node is fully bounded so we can eliminate any
6228 testing and branch directly to the target code. */
6229 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6231 GT, NULL_RTX, mode, unsignedp, 0,
6232 label_rtx (node->right->code_label));
6235 /* Right hand node requires testing.
6236 Branch to a label where we will handle it later. */
6238 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6239 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6241 GT, NULL_RTX, mode, unsignedp, 0,
6242 label_rtx (test_label));
6245 /* Value belongs to this node or to the left-hand subtree. */
6247 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6249 GE, NULL_RTX, mode, unsignedp, 0,
6250 label_rtx (node->code_label));
6252 /* Handle the left-hand subtree. */
6253 emit_case_nodes (index, node->left, default_label, index_type);
6255 /* If right node had to be handled later, do that now. */
6259 /* If the left-hand subtree fell through,
6260 don't let it fall into the right-hand subtree. */
6261 emit_jump_if_reachable (default_label);
6263 expand_label (test_label);
6264 emit_case_nodes (index, node->right, default_label, index_type);
6268 else if (node->right != 0 && node->left == 0)
6270 /* Deal with values to the left of this node,
6271 if they are possible. */
6272 if (!node_has_low_bound (node, index_type))
6274 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6276 LT, NULL_RTX, mode, unsignedp, 0,
6280 /* Value belongs to this node or to the right-hand subtree. */
6282 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6284 LE, NULL_RTX, mode, unsignedp, 0,
6285 label_rtx (node->code_label));
6287 emit_case_nodes (index, node->right, default_label, index_type);
6290 else if (node->right == 0 && node->left != 0)
6292 /* Deal with values to the right of this node,
6293 if they are possible. */
6294 if (!node_has_high_bound (node, index_type))
6296 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6298 GT, NULL_RTX, mode, unsignedp, 0,
6302 /* Value belongs to this node or to the left-hand subtree. */
6304 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6306 GE, NULL_RTX, mode, unsignedp, 0,
6307 label_rtx (node->code_label));
6309 emit_case_nodes (index, node->left, default_label, index_type);
6314 /* Node has no children so we check low and high bounds to remove
6315 redundant tests. Only one of the bounds can exist,
6316 since otherwise this node is bounded--a case tested already. */
6318 if (!node_has_high_bound (node, index_type))
6320 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6322 GT, NULL_RTX, mode, unsignedp, 0,
6326 if (!node_has_low_bound (node, index_type))
6328 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6330 LT, NULL_RTX, mode, unsignedp, 0,
6334 emit_jump (label_rtx (node->code_label));
6339 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6340 so that the debugging info will be correct for the unrolled loop. */
6343 find_loop_tree_blocks ()
6345 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6349 unroll_block_trees ()
6351 tree block = DECL_INITIAL (current_function_decl);
6353 reorder_blocks (block, get_insns ());