1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-99, 2000 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
68 /* Functions and data structures for expanding case statements. */
70 /* Case label structure, used to hold info on labels within case
71 statements. We handle "range" labels; for a single-value label
72 as in C, the high and low limits are the same.
74 An AVL tree of case nodes is initially created, and later transformed
75 to a list linked via the RIGHT fields in the nodes. Nodes with
76 higher case values are later in the list.
78 Switch statements can be output in one of two forms. A branch table
79 is used if there are more than a few labels and the labels are dense
80 within the range between the smallest and largest case value. If a
81 branch table is used, no further manipulations are done with the case
84 The alternative to the use of a branch table is to generate a series
85 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
86 and PARENT fields to hold a binary tree. Initially the tree is
87 totally unbalanced, with everything on the right. We balance the tree
88 with nodes on the left having lower case values than the parent
89 and nodes on the right having higher values. We then output the tree
94 struct case_node *left; /* Left son in binary tree */
95 struct case_node *right; /* Right son in binary tree; also node chain */
96 struct case_node *parent; /* Parent of node in binary tree */
97 tree low; /* Lowest index value for this label */
98 tree high; /* Highest index value for this label */
99 tree code_label; /* Label to jump to when node matches */
103 typedef struct case_node case_node;
104 typedef struct case_node *case_node_ptr;
106 /* These are used by estimate_case_costs and balance_case_nodes. */
108 /* This must be a signed type, and non-ANSI compilers lack signed char. */
109 static short cost_table_[129];
110 static short *cost_table;
111 static int use_cost_table;
113 /* Stack of control and binding constructs we are currently inside.
115 These constructs begin when you call `expand_start_WHATEVER'
116 and end when you call `expand_end_WHATEVER'. This stack records
117 info about how the construct began that tells the end-function
118 what to do. It also may provide information about the construct
119 to alter the behavior of other constructs within the body.
120 For example, they may affect the behavior of C `break' and `continue'.
122 Each construct gets one `struct nesting' object.
123 All of these objects are chained through the `all' field.
124 `nesting_stack' points to the first object (innermost construct).
125 The position of an entry on `nesting_stack' is in its `depth' field.
127 Each type of construct has its own individual stack.
128 For example, loops have `loop_stack'. Each object points to the
129 next object of the same type through the `next' field.
131 Some constructs are visible to `break' exit-statements and others
132 are not. Which constructs are visible depends on the language.
133 Therefore, the data structure allows each construct to be visible
134 or not, according to the args given when the construct is started.
135 The construct is visible if the `exit_label' field is non-null.
136 In that case, the value should be a CODE_LABEL rtx. */
141 struct nesting *next;
146 /* For conds (if-then and if-then-else statements). */
149 /* Label for the end of the if construct.
150 There is none if EXITFLAG was not set
151 and no `else' has been seen yet. */
153 /* Label for the end of this alternative.
154 This may be the end of the if or the next else/elseif. */
160 /* Label at the top of the loop; place to loop back to. */
162 /* Label at the end of the whole construct. */
164 /* Label before a jump that branches to the end of the whole
165 construct. This is where destructors go if any. */
167 /* Label for `continue' statement to jump to;
168 this is in front of the stepper of the loop. */
171 /* For variable binding contours. */
174 /* Sequence number of this binding contour within the function,
175 in order of entry. */
176 int block_start_count;
177 /* Nonzero => value to restore stack to on exit. */
179 /* The NOTE that starts this contour.
180 Used by expand_goto to check whether the destination
181 is within each contour or not. */
183 /* Innermost containing binding contour that has a stack level. */
184 struct nesting *innermost_stack_block;
185 /* List of cleanups to be run on exit from this contour.
186 This is a list of expressions to be evaluated.
187 The TREE_PURPOSE of each link is the ..._DECL node
188 which the cleanup pertains to. */
190 /* List of cleanup-lists of blocks containing this block,
191 as they were at the locus where this block appears.
192 There is an element for each containing block,
193 ordered innermost containing block first.
194 The tail of this list can be 0,
195 if all remaining elements would be empty lists.
196 The element's TREE_VALUE is the cleanup-list of that block,
197 which may be null. */
199 /* Chain of labels defined inside this binding contour.
200 For contours that have stack levels or cleanups. */
201 struct label_chain *label_chain;
202 /* Number of function calls seen, as of start of this block. */
203 int n_function_calls;
204 /* Nonzero if this is associated with a EH region. */
205 int exception_region;
206 /* The saved target_temp_slot_level from our outer block.
207 We may reset target_temp_slot_level to be the level of
208 this block, if that is done, target_temp_slot_level
209 reverts to the saved target_temp_slot_level at the very
211 int block_target_temp_slot_level;
212 /* True if we are currently emitting insns in an area of
213 output code that is controlled by a conditional
214 expression. This is used by the cleanup handling code to
215 generate conditional cleanup actions. */
216 int conditional_code;
217 /* A place to move the start of the exception region for any
218 of the conditional cleanups, must be at the end or after
219 the start of the last unconditional cleanup, and before any
220 conditional branch points. */
221 rtx last_unconditional_cleanup;
222 /* When in a conditional context, this is the specific
223 cleanup list associated with last_unconditional_cleanup,
224 where we place the conditionalized cleanups. */
227 /* For switch (C) or case (Pascal) statements,
228 and also for dummies (see `expand_start_case_dummy'). */
231 /* The insn after which the case dispatch should finally
232 be emitted. Zero for a dummy. */
234 /* A list of case labels; it is first built as an AVL tree.
235 During expand_end_case, this is converted to a list, and may be
236 rearranged into a nearly balanced binary tree. */
237 struct case_node *case_list;
238 /* Label to jump to if no case matches. */
240 /* The expression to be dispatched on. */
242 /* Type that INDEX_EXPR should be converted to. */
244 /* Number of range exprs in case statement. */
246 /* Name of this kind of statement, for warnings. */
247 const char *printname;
248 /* Used to save no_line_numbers till we see the first case label.
249 We set this to -1 when we see the first case label in this
251 int line_number_status;
256 /* Allocate and return a new `struct nesting'. */
258 #define ALLOC_NESTING() \
259 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
261 /* Pop the nesting stack element by element until we pop off
262 the element which is at the top of STACK.
263 Update all the other stacks, popping off elements from them
264 as we pop them from nesting_stack. */
266 #define POPSTACK(STACK) \
267 do { struct nesting *target = STACK; \
268 struct nesting *this; \
269 do { this = nesting_stack; \
270 if (loop_stack == this) \
271 loop_stack = loop_stack->next; \
272 if (cond_stack == this) \
273 cond_stack = cond_stack->next; \
274 if (block_stack == this) \
275 block_stack = block_stack->next; \
276 if (stack_block_stack == this) \
277 stack_block_stack = stack_block_stack->next; \
278 if (case_stack == this) \
279 case_stack = case_stack->next; \
280 nesting_depth = nesting_stack->depth - 1; \
281 nesting_stack = this->all; \
282 obstack_free (&stmt_obstack, this); } \
283 while (this != target); } while (0)
285 /* In some cases it is impossible to generate code for a forward goto
286 until the label definition is seen. This happens when it may be necessary
287 for the goto to reset the stack pointer: we don't yet know how to do that.
288 So expand_goto puts an entry on this fixup list.
289 Each time a binding contour that resets the stack is exited,
291 If the target label has now been defined, we can insert the proper code. */
295 /* Points to following fixup. */
296 struct goto_fixup *next;
297 /* Points to the insn before the jump insn.
298 If more code must be inserted, it goes after this insn. */
300 /* The LABEL_DECL that this jump is jumping to, or 0
301 for break, continue or return. */
303 /* The BLOCK for the place where this goto was found. */
305 /* The CODE_LABEL rtx that this is jumping to. */
307 /* Number of binding contours started in current function
308 before the label reference. */
309 int block_start_count;
310 /* The outermost stack level that should be restored for this jump.
311 Each time a binding contour that resets the stack is exited,
312 if the target label is *not* yet defined, this slot is updated. */
314 /* List of lists of cleanup expressions to be run by this goto.
315 There is one element for each block that this goto is within.
316 The tail of this list can be 0,
317 if all remaining elements would be empty.
318 The TREE_VALUE contains the cleanup list of that block as of the
319 time this goto was seen.
320 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
321 tree cleanup_list_list;
324 /* Within any binding contour that must restore a stack level,
325 all labels are recorded with a chain of these structures. */
329 /* Points to following fixup. */
330 struct label_chain *next;
336 /* Chain of all pending binding contours. */
337 struct nesting *x_block_stack;
339 /* If any new stacks are added here, add them to POPSTACKS too. */
341 /* Chain of all pending binding contours that restore stack levels
343 struct nesting *x_stack_block_stack;
345 /* Chain of all pending conditional statements. */
346 struct nesting *x_cond_stack;
348 /* Chain of all pending loops. */
349 struct nesting *x_loop_stack;
351 /* Chain of all pending case or switch statements. */
352 struct nesting *x_case_stack;
354 /* Separate chain including all of the above,
355 chained through the `all' field. */
356 struct nesting *x_nesting_stack;
358 /* Number of entries on nesting_stack now. */
361 /* Number of binding contours started so far in this function. */
362 int x_block_start_count;
364 /* Each time we expand an expression-statement,
365 record the expr's type and its RTL value here. */
366 tree x_last_expr_type;
367 rtx x_last_expr_value;
369 /* Nonzero if within a ({...}) grouping, in which case we must
370 always compute a value for each expr-stmt in case it is the last one. */
371 int x_expr_stmts_for_value;
373 /* Filename and line number of last line-number note,
374 whether we actually emitted it or not. */
375 char *x_emit_filename;
378 struct goto_fixup *x_goto_fixup_chain;
381 #define block_stack (cfun->stmt->x_block_stack)
382 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
383 #define cond_stack (cfun->stmt->x_cond_stack)
384 #define loop_stack (cfun->stmt->x_loop_stack)
385 #define case_stack (cfun->stmt->x_case_stack)
386 #define nesting_stack (cfun->stmt->x_nesting_stack)
387 #define nesting_depth (cfun->stmt->x_nesting_depth)
388 #define current_block_start_count (cfun->stmt->x_block_start_count)
389 #define last_expr_type (cfun->stmt->x_last_expr_type)
390 #define last_expr_value (cfun->stmt->x_last_expr_value)
391 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
392 #define emit_filename (cfun->stmt->x_emit_filename)
393 #define emit_lineno (cfun->stmt->x_emit_lineno)
394 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
396 /* Non-zero if we are using EH to handle cleanus. */
397 static int using_eh_for_cleanups_p = 0;
399 /* Character strings, each containing a single decimal digit. */
400 static char *digit_strings[10];
403 static int n_occurrences PARAMS ((int, const char *));
404 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
405 static int expand_fixup PARAMS ((tree, rtx, rtx));
406 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
407 static void expand_nl_goto_receiver PARAMS ((void));
408 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
409 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
411 static void expand_null_return_1 PARAMS ((rtx, int));
412 static void expand_value_return PARAMS ((rtx));
413 static int tail_recursion_args PARAMS ((tree, tree));
414 static void expand_cleanups PARAMS ((tree, tree, int, int));
415 static void check_seenlabel PARAMS ((void));
416 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
417 static int estimate_case_costs PARAMS ((case_node_ptr));
418 static void group_case_nodes PARAMS ((case_node_ptr));
419 static void balance_case_nodes PARAMS ((case_node_ptr *,
421 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
422 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
423 static int node_is_bounded PARAMS ((case_node_ptr, tree));
424 static void emit_jump_if_reachable PARAMS ((rtx));
425 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
426 static int add_case_node PARAMS ((tree, tree, tree, tree *));
427 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
428 static void mark_cond_nesting PARAMS ((struct nesting *));
429 static void mark_loop_nesting PARAMS ((struct nesting *));
430 static void mark_block_nesting PARAMS ((struct nesting *));
431 static void mark_case_nesting PARAMS ((struct nesting *));
432 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
436 using_eh_for_cleanups ()
438 using_eh_for_cleanups_p = 1;
441 /* Mark N (known to be a cond-nesting) for GC. */
444 mark_cond_nesting (n)
449 ggc_mark_rtx (n->exit_label);
450 ggc_mark_rtx (n->data.cond.endif_label);
451 ggc_mark_rtx (n->data.cond.next_label);
457 /* Mark N (known to be a loop-nesting) for GC. */
460 mark_loop_nesting (n)
466 ggc_mark_rtx (n->exit_label);
467 ggc_mark_rtx (n->data.loop.start_label);
468 ggc_mark_rtx (n->data.loop.end_label);
469 ggc_mark_rtx (n->data.loop.alt_end_label);
470 ggc_mark_rtx (n->data.loop.continue_label);
476 /* Mark N (known to be a block-nesting) for GC. */
479 mark_block_nesting (n)
484 struct label_chain *l;
486 ggc_mark_rtx (n->exit_label);
487 ggc_mark_rtx (n->data.block.stack_level);
488 ggc_mark_rtx (n->data.block.first_insn);
489 ggc_mark_tree (n->data.block.cleanups);
490 ggc_mark_tree (n->data.block.outer_cleanups);
492 for (l = n->data.block.label_chain; l != NULL; l = l->next)
493 ggc_mark_tree (l->label);
495 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
497 /* ??? cleanup_ptr never points outside the stack, does it? */
503 /* Mark N (known to be a case-nesting) for GC. */
506 mark_case_nesting (n)
511 struct case_node *node;
513 ggc_mark_rtx (n->exit_label);
514 ggc_mark_rtx (n->data.case_stmt.start);
516 node = n->data.case_stmt.case_list;
519 ggc_mark_tree (node->low);
520 ggc_mark_tree (node->high);
521 ggc_mark_tree (node->code_label);
525 ggc_mark_tree (n->data.case_stmt.default_label);
526 ggc_mark_tree (n->data.case_stmt.index_expr);
527 ggc_mark_tree (n->data.case_stmt.nominal_type);
537 struct goto_fixup *g;
541 ggc_mark_rtx (g->before_jump);
542 ggc_mark_tree (g->target);
543 ggc_mark_tree (g->context);
544 ggc_mark_rtx (g->target_rtl);
545 ggc_mark_rtx (g->stack_level);
546 ggc_mark_tree (g->cleanup_list_list);
552 /* Clear out all parts of the state in F that can safely be discarded
553 after the function has been compiled, to let garbage collection
554 reclaim the memory. */
560 /* We're about to free the function obstack. If we hold pointers to
561 things allocated there, then we'll try to mark them when we do
562 GC. So, we clear them out here explicitly. */
572 struct stmt_status *p;
577 mark_block_nesting (p->x_block_stack);
578 mark_cond_nesting (p->x_cond_stack);
579 mark_loop_nesting (p->x_loop_stack);
580 mark_case_nesting (p->x_case_stack);
582 ggc_mark_tree (p->x_last_expr_type);
583 /* last_epxr_value is only valid if last_expr_type is nonzero. */
584 if (p->x_last_expr_type)
585 ggc_mark_rtx (p->x_last_expr_value);
587 mark_goto_fixup (p->x_goto_fixup_chain);
595 gcc_obstack_init (&stmt_obstack);
597 for (i = 0; i < 10; i++)
599 digit_strings[i] = ggc_alloc_string (NULL, 1);
600 digit_strings[i][0] = '0' + i;
602 ggc_add_string_root (digit_strings, 10);
606 init_stmt_for_function ()
608 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
610 /* We are not currently within any block, conditional, loop or case. */
612 stack_block_stack = 0;
619 current_block_start_count = 0;
621 /* No gotos have been expanded yet. */
622 goto_fixup_chain = 0;
624 /* We are not processing a ({...}) grouping. */
625 expr_stmts_for_value = 0;
627 last_expr_value = NULL_RTX;
630 /* Return nonzero if anything is pushed on the loop, condition, or case
635 return cond_stack || loop_stack || case_stack;
638 /* Record the current file and line. Called from emit_line_note. */
640 set_file_and_line_for_stmt (file, line)
644 emit_filename = file;
648 /* Emit a no-op instruction. */
655 last_insn = get_last_insn ();
657 && (GET_CODE (last_insn) == CODE_LABEL
658 || (GET_CODE (last_insn) == NOTE
659 && prev_real_insn (last_insn) == 0)))
660 emit_insn (gen_nop ());
663 /* Return the rtx-label that corresponds to a LABEL_DECL,
664 creating it if necessary. */
670 if (TREE_CODE (label) != LABEL_DECL)
673 if (DECL_RTL (label))
674 return DECL_RTL (label);
676 return DECL_RTL (label) = gen_label_rtx ();
679 /* Add an unconditional jump to LABEL as the next sequential instruction. */
685 do_pending_stack_adjust ();
686 emit_jump_insn (gen_jump (label));
690 /* Emit code to jump to the address
691 specified by the pointer expression EXP. */
694 expand_computed_goto (exp)
697 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
699 #ifdef POINTERS_EXTEND_UNSIGNED
700 x = convert_memory_address (Pmode, x);
704 /* Be sure the function is executable. */
705 if (current_function_check_memory_usage)
706 emit_library_call (chkr_check_exec_libfunc, 1,
707 VOIDmode, 1, x, ptr_mode);
709 do_pending_stack_adjust ();
710 emit_indirect_jump (x);
712 current_function_has_computed_jump = 1;
715 /* Handle goto statements and the labels that they can go to. */
717 /* Specify the location in the RTL code of a label LABEL,
718 which is a LABEL_DECL tree node.
720 This is used for the kind of label that the user can jump to with a
721 goto statement, and for alternatives of a switch or case statement.
722 RTL labels generated for loops and conditionals don't go through here;
723 they are generated directly at the RTL level, by other functions below.
725 Note that this has nothing to do with defining label *names*.
726 Languages vary in how they do that and what that even means. */
732 struct label_chain *p;
734 do_pending_stack_adjust ();
735 emit_label (label_rtx (label));
736 if (DECL_NAME (label))
737 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
739 if (stack_block_stack != 0)
741 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
742 p->next = stack_block_stack->data.block.label_chain;
743 stack_block_stack->data.block.label_chain = p;
748 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
749 from nested functions. */
752 declare_nonlocal_label (label)
755 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
757 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
758 LABEL_PRESERVE_P (label_rtx (label)) = 1;
759 if (nonlocal_goto_handler_slots == 0)
761 emit_stack_save (SAVE_NONLOCAL,
762 &nonlocal_goto_stack_level,
763 PREV_INSN (tail_recursion_reentry));
765 nonlocal_goto_handler_slots
766 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
769 /* Generate RTL code for a `goto' statement with target label LABEL.
770 LABEL should be a LABEL_DECL tree node that was or will later be
771 defined with `expand_label'. */
779 /* Check for a nonlocal goto to a containing function. */
780 context = decl_function_context (label);
781 if (context != 0 && context != current_function_decl)
783 struct function *p = find_function_data (context);
784 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
785 rtx temp, handler_slot;
788 /* Find the corresponding handler slot for this label. */
789 handler_slot = p->x_nonlocal_goto_handler_slots;
790 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
791 link = TREE_CHAIN (link))
792 handler_slot = XEXP (handler_slot, 1);
793 handler_slot = XEXP (handler_slot, 0);
795 p->has_nonlocal_label = 1;
796 current_function_has_nonlocal_goto = 1;
797 LABEL_REF_NONLOCAL_P (label_ref) = 1;
799 /* Copy the rtl for the slots so that they won't be shared in
800 case the virtual stack vars register gets instantiated differently
801 in the parent than in the child. */
803 #if HAVE_nonlocal_goto
804 if (HAVE_nonlocal_goto)
805 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
806 copy_rtx (handler_slot),
807 copy_rtx (p->x_nonlocal_goto_stack_level),
814 /* Restore frame pointer for containing function.
815 This sets the actual hard register used for the frame pointer
816 to the location of the function's incoming static chain info.
817 The non-local goto handler will then adjust it to contain the
818 proper value and reload the argument pointer, if needed. */
819 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
821 /* We have now loaded the frame pointer hardware register with
822 the address of that corresponds to the start of the virtual
823 stack vars. So replace virtual_stack_vars_rtx in all
824 addresses we use with stack_pointer_rtx. */
826 /* Get addr of containing function's current nonlocal goto handler,
827 which will do any cleanups and then jump to the label. */
828 addr = copy_rtx (handler_slot);
829 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
830 hard_frame_pointer_rtx));
832 /* Restore the stack pointer. Note this uses fp just restored. */
833 addr = p->x_nonlocal_goto_stack_level;
835 addr = replace_rtx (copy_rtx (addr),
836 virtual_stack_vars_rtx,
837 hard_frame_pointer_rtx);
839 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
841 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
843 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
844 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
845 emit_indirect_jump (temp);
849 expand_goto_internal (label, label_rtx (label), NULL_RTX);
852 /* Generate RTL code for a `goto' statement with target label BODY.
853 LABEL should be a LABEL_REF.
854 LAST_INSN, if non-0, is the rtx we should consider as the last
855 insn emitted (for the purposes of cleaning up a return). */
858 expand_goto_internal (body, label, last_insn)
863 struct nesting *block;
866 if (GET_CODE (label) != CODE_LABEL)
869 /* If label has already been defined, we can tell now
870 whether and how we must alter the stack level. */
872 if (PREV_INSN (label) != 0)
874 /* Find the innermost pending block that contains the label.
875 (Check containment by comparing insn-uids.)
876 Then restore the outermost stack level within that block,
877 and do cleanups of all blocks contained in it. */
878 for (block = block_stack; block; block = block->next)
880 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
882 if (block->data.block.stack_level != 0)
883 stack_level = block->data.block.stack_level;
884 /* Execute the cleanups for blocks we are exiting. */
885 if (block->data.block.cleanups != 0)
887 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
888 do_pending_stack_adjust ();
894 /* Ensure stack adjust isn't done by emit_jump, as this
895 would clobber the stack pointer. This one should be
896 deleted as dead by flow. */
897 clear_pending_stack_adjust ();
898 do_pending_stack_adjust ();
899 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
902 if (body != 0 && DECL_TOO_LATE (body))
903 error ("jump to `%s' invalidly jumps into binding contour",
904 IDENTIFIER_POINTER (DECL_NAME (body)));
906 /* Label not yet defined: may need to put this goto
907 on the fixup list. */
908 else if (! expand_fixup (body, label, last_insn))
910 /* No fixup needed. Record that the label is the target
911 of at least one goto that has no fixup. */
913 TREE_ADDRESSABLE (body) = 1;
919 /* Generate if necessary a fixup for a goto
920 whose target label in tree structure (if any) is TREE_LABEL
921 and whose target in rtl is RTL_LABEL.
923 If LAST_INSN is nonzero, we pretend that the jump appears
924 after insn LAST_INSN instead of at the current point in the insn stream.
926 The fixup will be used later to insert insns just before the goto.
927 Those insns will restore the stack level as appropriate for the
928 target label, and will (in the case of C++) also invoke any object
929 destructors which have to be invoked when we exit the scopes which
930 are exited by the goto.
932 Value is nonzero if a fixup is made. */
935 expand_fixup (tree_label, rtl_label, last_insn)
940 struct nesting *block, *end_block;
942 /* See if we can recognize which block the label will be output in.
943 This is possible in some very common cases.
944 If we succeed, set END_BLOCK to that block.
945 Otherwise, set it to 0. */
948 && (rtl_label == cond_stack->data.cond.endif_label
949 || rtl_label == cond_stack->data.cond.next_label))
950 end_block = cond_stack;
951 /* If we are in a loop, recognize certain labels which
952 are likely targets. This reduces the number of fixups
953 we need to create. */
955 && (rtl_label == loop_stack->data.loop.start_label
956 || rtl_label == loop_stack->data.loop.end_label
957 || rtl_label == loop_stack->data.loop.continue_label))
958 end_block = loop_stack;
962 /* Now set END_BLOCK to the binding level to which we will return. */
966 struct nesting *next_block = end_block->all;
969 /* First see if the END_BLOCK is inside the innermost binding level.
970 If so, then no cleanups or stack levels are relevant. */
971 while (next_block && next_block != block)
972 next_block = next_block->all;
977 /* Otherwise, set END_BLOCK to the innermost binding level
978 which is outside the relevant control-structure nesting. */
979 next_block = block_stack->next;
980 for (block = block_stack; block != end_block; block = block->all)
981 if (block == next_block)
982 next_block = next_block->next;
983 end_block = next_block;
986 /* Does any containing block have a stack level or cleanups?
987 If not, no fixup is needed, and that is the normal case
988 (the only case, for standard C). */
989 for (block = block_stack; block != end_block; block = block->next)
990 if (block->data.block.stack_level != 0
991 || block->data.block.cleanups != 0)
994 if (block != end_block)
996 /* Ok, a fixup is needed. Add a fixup to the list of such. */
997 struct goto_fixup *fixup
998 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
999 /* In case an old stack level is restored, make sure that comes
1000 after any pending stack adjust. */
1001 /* ?? If the fixup isn't to come at the present position,
1002 doing the stack adjust here isn't useful. Doing it with our
1003 settings at that location isn't useful either. Let's hope
1006 do_pending_stack_adjust ();
1007 fixup->target = tree_label;
1008 fixup->target_rtl = rtl_label;
1010 /* Create a BLOCK node and a corresponding matched set of
1011 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1012 this point. The notes will encapsulate any and all fixup
1013 code which we might later insert at this point in the insn
1014 stream. Also, the BLOCK node will be the parent (i.e. the
1015 `SUPERBLOCK') of any other BLOCK nodes which we might create
1016 later on when we are expanding the fixup code.
1018 Note that optimization passes (including expand_end_loop)
1019 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1020 as a placeholder. */
1023 register rtx original_before_jump
1024 = last_insn ? last_insn : get_last_insn ();
1029 block = make_node (BLOCK);
1030 TREE_USED (block) = 1;
1032 if (!cfun->x_whole_function_mode_p)
1033 insert_block (block);
1037 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1038 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1043 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1044 if (cfun->x_whole_function_mode_p)
1045 NOTE_BLOCK (start) = block;
1046 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1047 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1048 if (cfun->x_whole_function_mode_p)
1049 NOTE_BLOCK (end) = block;
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 /* If this fixup jumped into this contour from before the beginning
1126 of this contour, report an error. This code used to use
1127 the first non-label insn after f->target_rtl, but that's
1128 wrong since such can be added, by things like put_var_into_stack
1129 and have INSN_UIDs that are out of the range of the block. */
1130 /* ??? Bug: this does not detect jumping in through intermediate
1131 blocks that have stack levels or cleanups.
1132 It detects only a problem with the innermost block
1133 around the label. */
1135 && (dont_jump_in || stack_level || cleanup_list)
1136 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1137 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1138 && ! DECL_ERROR_ISSUED (f->target))
1140 error_with_decl (f->target,
1141 "label `%s' used before containing binding contour");
1142 /* Prevent multiple errors for one label. */
1143 DECL_ERROR_ISSUED (f->target) = 1;
1146 /* We will expand the cleanups into a sequence of their own and
1147 then later on we will attach this new sequence to the insn
1148 stream just ahead of the actual jump insn. */
1152 /* Temporarily restore the lexical context where we will
1153 logically be inserting the fixup code. We do this for the
1154 sake of getting the debugging information right. */
1157 set_block (f->context);
1159 /* Expand the cleanups for blocks this jump exits. */
1160 if (f->cleanup_list_list)
1163 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1164 /* Marked elements correspond to blocks that have been closed.
1165 Do their cleanups. */
1166 if (TREE_ADDRESSABLE (lists)
1167 && TREE_VALUE (lists) != 0)
1169 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1170 /* Pop any pushes done in the cleanups,
1171 in case function is about to return. */
1172 do_pending_stack_adjust ();
1176 /* Restore stack level for the biggest contour that this
1177 jump jumps out of. */
1179 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1181 /* Finish up the sequence containing the insns which implement the
1182 necessary cleanups, and then attach that whole sequence to the
1183 insn stream just ahead of the actual jump insn. Attaching it
1184 at that point insures that any cleanups which are in fact
1185 implicit C++ object destructions (which must be executed upon
1186 leaving the block) appear (to the debugger) to be taking place
1187 in an area of the generated code where the object(s) being
1188 destructed are still "in scope". */
1190 cleanup_insns = get_insns ();
1194 emit_insns_after (cleanup_insns, f->before_jump);
1201 /* For any still-undefined labels, do the cleanups for this block now.
1202 We must do this now since items in the cleanup list may go out
1203 of scope when the block ends. */
1204 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1205 if (f->before_jump != 0
1206 && PREV_INSN (f->target_rtl) == 0
1207 /* Label has still not appeared. If we are exiting a block with
1208 a stack level to restore, that started before the fixup,
1209 mark this stack level as needing restoration
1210 when the fixup is later finalized. */
1212 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1213 means the label is undefined. That's erroneous, but possible. */
1214 && (thisblock->data.block.block_start_count
1215 <= f->block_start_count))
1217 tree lists = f->cleanup_list_list;
1220 for (; lists; lists = TREE_CHAIN (lists))
1221 /* If the following elt. corresponds to our containing block
1222 then the elt. must be for this block. */
1223 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1227 set_block (f->context);
1228 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1229 do_pending_stack_adjust ();
1230 cleanup_insns = get_insns ();
1233 if (cleanup_insns != 0)
1235 = emit_insns_after (cleanup_insns, f->before_jump);
1237 f->cleanup_list_list = TREE_CHAIN (lists);
1241 f->stack_level = stack_level;
1245 /* Return the number of times character C occurs in string S. */
1247 n_occurrences (c, s)
1257 /* Generate RTL for an asm statement (explicit assembler code).
1258 BODY is a STRING_CST node containing the assembler code text,
1259 or an ADDR_EXPR containing a STRING_CST. */
1265 if (current_function_check_memory_usage)
1267 error ("`asm' cannot be used in function where memory usage is checked");
1271 if (TREE_CODE (body) == ADDR_EXPR)
1272 body = TREE_OPERAND (body, 0);
1274 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1275 TREE_STRING_POINTER (body)));
1279 /* Generate RTL for an asm statement with arguments.
1280 STRING is the instruction template.
1281 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1282 Each output or input has an expression in the TREE_VALUE and
1283 a constraint-string in the TREE_PURPOSE.
1284 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1285 that is clobbered by this insn.
1287 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1288 Some elements of OUTPUTS may be replaced with trees representing temporary
1289 values. The caller should copy those temporary values to the originally
1292 VOL nonzero means the insn is volatile; don't optimize it. */
1295 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1296 tree string, outputs, inputs, clobbers;
1301 rtvec argvec, constraints;
1303 int ninputs = list_length (inputs);
1304 int noutputs = list_length (outputs);
1309 /* Vector of RTX's of evaluated output operands. */
1310 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1311 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1312 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1313 enum machine_mode *inout_mode
1314 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1315 /* The insn we have emitted. */
1318 /* An ASM with no outputs needs to be treated as volatile, for now. */
1322 if (current_function_check_memory_usage)
1324 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1328 #ifdef MD_ASM_CLOBBERS
1329 /* Sometimes we wish to automatically clobber registers across an asm.
1330 Case in point is when the i386 backend moved from cc0 to a hard reg --
1331 maintaining source-level compatability means automatically clobbering
1332 the flags register. */
1333 MD_ASM_CLOBBERS (clobbers);
1336 if (current_function_check_memory_usage)
1338 error ("`asm' cannot be used in function where memory usage is checked");
1342 /* Count the number of meaningful clobbered registers, ignoring what
1343 we would ignore later. */
1345 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1347 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1349 i = decode_reg_name (regname);
1350 if (i >= 0 || i == -4)
1353 error ("unknown register name `%s' in `asm'", regname);
1358 /* Check that the number of alternatives is constant across all
1360 if (outputs || inputs)
1362 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1363 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1366 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1368 error ("too many alternatives in `asm'");
1375 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1377 if (n_occurrences (',', constraint) != nalternatives)
1379 error ("operand constraints for `asm' differ in number of alternatives");
1383 if (TREE_CHAIN (tmp))
1384 tmp = TREE_CHAIN (tmp);
1386 tmp = next, next = 0;
1390 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1392 tree val = TREE_VALUE (tail);
1393 tree type = TREE_TYPE (val);
1402 /* If there's an erroneous arg, emit no insn. */
1403 if (TREE_TYPE (val) == error_mark_node)
1406 /* Make sure constraint has `=' and does not have `+'. Also, see
1407 if it allows any register. Be liberal on the latter test, since
1408 the worst that happens if we get it wrong is we issue an error
1411 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1412 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1414 /* Allow the `=' or `+' to not be at the beginning of the string,
1415 since it wasn't explicitly documented that way, and there is a
1416 large body of code that puts it last. Swap the character to
1417 the front, so as not to uglify any place else. */
1421 if ((p = strchr (constraint, '=')) != NULL)
1423 if ((p = strchr (constraint, '+')) != NULL)
1426 error ("output operand constraint lacks `='");
1430 if (p != constraint)
1433 bcopy (constraint, constraint+1, p-constraint);
1436 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1439 is_inout = constraint[0] == '+';
1440 /* Replace '+' with '='. */
1441 constraint[0] = '=';
1442 /* Make sure we can specify the matching operand. */
1443 if (is_inout && i > 9)
1445 error ("output operand constraint %d contains `+'", i);
1449 for (j = 1; j < c_len; j++)
1450 switch (constraint[j])
1454 error ("operand constraint contains '+' or '=' at illegal position.");
1458 if (i + 1 == ninputs + noutputs)
1460 error ("`%%' constraint used with last operand");
1465 case '?': case '!': case '*': case '&':
1466 case 'E': case 'F': case 'G': case 'H':
1467 case 's': case 'i': case 'n':
1468 case 'I': case 'J': case 'K': case 'L': case 'M':
1469 case 'N': case 'O': case 'P': case ',':
1470 #ifdef EXTRA_CONSTRAINT
1471 case 'Q': case 'R': case 'S': case 'T': case 'U':
1475 case '0': case '1': case '2': case '3': case '4':
1476 case '5': case '6': case '7': case '8': case '9':
1477 error ("matching constraint not valid in output operand");
1480 case 'V': case 'm': case 'o':
1485 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1486 excepting those that expand_call created. So match memory
1502 /* If an output operand is not a decl or indirect ref and our constraint
1503 allows a register, make a temporary to act as an intermediate.
1504 Make the asm insn write into that, then our caller will copy it to
1505 the real output operand. Likewise for promoted variables. */
1507 real_output_rtx[i] = NULL_RTX;
1508 if ((TREE_CODE (val) == INDIRECT_REF
1510 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1511 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1512 && ! (GET_CODE (DECL_RTL (val)) == REG
1513 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1518 mark_addressable (TREE_VALUE (tail));
1521 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1522 EXPAND_MEMORY_USE_WO);
1524 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1525 error ("output number %d not directly addressable", i);
1526 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1528 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1529 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1531 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1536 output_rtx[i] = assign_temp (type, 0, 0, 0);
1537 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1542 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1543 inout_opnum[ninout++] = i;
1548 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1550 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1554 /* Make vectors for the expression-rtx and constraint strings. */
1556 argvec = rtvec_alloc (ninputs);
1557 constraints = rtvec_alloc (ninputs);
1559 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1560 empty_string, 0, argvec, constraints,
1563 MEM_VOLATILE_P (body) = vol;
1565 /* Eval the inputs and put them into ARGVEC.
1566 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1569 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1572 int allows_reg = 0, allows_mem = 0;
1573 char *constraint, *orig_constraint;
1577 /* If there's an erroneous arg, emit no insn,
1578 because the ASM_INPUT would get VOIDmode
1579 and that could cause a crash in reload. */
1580 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1583 /* ??? Can this happen, and does the error message make any sense? */
1584 if (TREE_PURPOSE (tail) == NULL_TREE)
1586 error ("hard register `%s' listed as input operand to `asm'",
1587 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1591 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1592 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1593 orig_constraint = constraint;
1595 /* Make sure constraint has neither `=', `+', nor '&'. */
1597 for (j = 0; j < c_len; j++)
1598 switch (constraint[j])
1600 case '+': case '=': case '&':
1601 if (constraint == orig_constraint)
1603 error ("input operand constraint contains `%c'",
1610 if (constraint == orig_constraint
1611 && i + 1 == ninputs - ninout)
1613 error ("`%%' constraint used with last operand");
1618 case 'V': case 'm': case 'o':
1623 case '?': case '!': case '*':
1624 case 'E': case 'F': case 'G': case 'H': case 'X':
1625 case 's': case 'i': case 'n':
1626 case 'I': case 'J': case 'K': case 'L': case 'M':
1627 case 'N': case 'O': case 'P': case ',':
1628 #ifdef EXTRA_CONSTRAINT
1629 case 'Q': case 'R': case 'S': case 'T': case 'U':
1633 /* Whether or not a numeric constraint allows a register is
1634 decided by the matching constraint, and so there is no need
1635 to do anything special with them. We must handle them in
1636 the default case, so that we don't unnecessarily force
1637 operands to memory. */
1638 case '0': case '1': case '2': case '3': case '4':
1639 case '5': case '6': case '7': case '8': case '9':
1640 if (constraint[j] >= '0' + noutputs)
1643 ("matching constraint references invalid operand number");
1647 /* Try and find the real constraint for this dup. */
1648 if ((j == 0 && c_len == 1)
1649 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1653 for (j = constraint[j] - '0'; j > 0; --j)
1656 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1657 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1662 /* ... fall through ... */
1675 if (! allows_reg && allows_mem)
1676 mark_addressable (TREE_VALUE (tail));
1678 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1680 if (asm_operand_ok (op, constraint) <= 0)
1683 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1684 else if (!allows_mem)
1685 warning ("asm operand %d probably doesn't match constraints", i);
1686 else if (CONSTANT_P (op))
1687 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1689 else if (GET_CODE (op) == REG
1690 || GET_CODE (op) == SUBREG
1691 || GET_CODE (op) == CONCAT)
1693 tree type = TREE_TYPE (TREE_VALUE (tail));
1694 rtx memloc = assign_temp (type, 1, 1, 1);
1696 emit_move_insn (memloc, op);
1700 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1701 /* We won't recognize volatile memory as available a
1702 memory_operand at this point. Ignore it. */
1704 else if (queued_subexp_p (op))
1707 /* ??? Leave this only until we have experience with what
1708 happens in combine and elsewhere when constraints are
1710 warning ("asm operand %d probably doesn't match constraints", i);
1712 XVECEXP (body, 3, i) = op;
1714 XVECEXP (body, 4, i) /* constraints */
1715 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1720 /* Protect all the operands from the queue now that they have all been
1723 for (i = 0; i < ninputs - ninout; i++)
1724 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1726 for (i = 0; i < noutputs; i++)
1727 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1729 /* For in-out operands, copy output rtx to input rtx. */
1730 for (i = 0; i < ninout; i++)
1732 int j = inout_opnum[i];
1734 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1736 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1737 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1740 /* Now, for each output, construct an rtx
1741 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1742 ARGVEC CONSTRAINTS))
1743 If there is more than one, put them inside a PARALLEL. */
1745 if (noutputs == 1 && nclobbers == 0)
1747 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1748 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);
1765 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1767 /* For each output operand, store a SET. */
1768 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1770 XVECEXP (body, 0, i)
1771 = gen_rtx_SET (VOIDmode,
1773 gen_rtx_ASM_OPERANDS
1775 TREE_STRING_POINTER (string),
1776 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1777 i, argvec, constraints,
1780 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1783 /* If there are no outputs (but there are some clobbers)
1784 store the bare ASM_OPERANDS into the PARALLEL. */
1787 XVECEXP (body, 0, i++) = obody;
1789 /* Store (clobber REG) for each clobbered register specified. */
1791 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1793 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1794 int j = decode_reg_name (regname);
1798 if (j == -3) /* `cc', which is not a register */
1801 if (j == -4) /* `memory', don't cache memory across asm */
1803 XVECEXP (body, 0, i++)
1804 = gen_rtx_CLOBBER (VOIDmode,
1807 gen_rtx_SCRATCH (VOIDmode)));
1811 /* Ignore unknown register, error already signaled. */
1815 /* Use QImode since that's guaranteed to clobber just one reg. */
1816 XVECEXP (body, 0, i++)
1817 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1820 insn = emit_insn (body);
1823 /* For any outputs that needed reloading into registers, spill them
1824 back to where they belong. */
1825 for (i = 0; i < noutputs; ++i)
1826 if (real_output_rtx[i])
1827 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1832 /* Generate RTL to evaluate the expression EXP
1833 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1836 expand_expr_stmt (exp)
1839 /* If -W, warn about statements with no side effects,
1840 except for an explicit cast to void (e.g. for assert()), and
1841 except inside a ({...}) where they may be useful. */
1842 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1844 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1845 && !(TREE_CODE (exp) == CONVERT_EXPR
1846 && TREE_TYPE (exp) == void_type_node))
1847 warning_with_file_and_line (emit_filename, emit_lineno,
1848 "statement with no effect");
1849 else if (warn_unused)
1850 warn_if_unused_value (exp);
1853 /* If EXP is of function type and we are expanding statements for
1854 value, convert it to pointer-to-function. */
1855 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1856 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1858 last_expr_type = TREE_TYPE (exp);
1859 last_expr_value = expand_expr (exp,
1860 (expr_stmts_for_value
1861 ? NULL_RTX : const0_rtx),
1864 /* If all we do is reference a volatile value in memory,
1865 copy it to a register to be sure it is actually touched. */
1866 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1867 && TREE_THIS_VOLATILE (exp))
1869 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1871 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1872 copy_to_reg (last_expr_value);
1875 rtx lab = gen_label_rtx ();
1877 /* Compare the value with itself to reference it. */
1878 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1879 expand_expr (TYPE_SIZE (last_expr_type),
1880 NULL_RTX, VOIDmode, 0),
1882 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1888 /* If this expression is part of a ({...}) and is in memory, we may have
1889 to preserve temporaries. */
1890 preserve_temp_slots (last_expr_value);
1892 /* Free any temporaries used to evaluate this expression. Any temporary
1893 used as a result of this expression will already have been preserved
1900 /* Warn if EXP contains any computations whose results are not used.
1901 Return 1 if a warning is printed; 0 otherwise. */
1904 warn_if_unused_value (exp)
1907 if (TREE_USED (exp))
1910 switch (TREE_CODE (exp))
1912 case PREINCREMENT_EXPR:
1913 case POSTINCREMENT_EXPR:
1914 case PREDECREMENT_EXPR:
1915 case POSTDECREMENT_EXPR:
1920 case METHOD_CALL_EXPR:
1922 case TRY_CATCH_EXPR:
1923 case WITH_CLEANUP_EXPR:
1925 /* We don't warn about COND_EXPR because it may be a useful
1926 construct if either arm contains a side effect. */
1931 /* For a binding, warn if no side effect within it. */
1932 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1935 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1937 case TRUTH_ORIF_EXPR:
1938 case TRUTH_ANDIF_EXPR:
1939 /* In && or ||, warn if 2nd operand has no side effect. */
1940 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1943 if (TREE_NO_UNUSED_WARNING (exp))
1945 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1947 /* Let people do `(foo (), 0)' without a warning. */
1948 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1950 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1954 case NON_LVALUE_EXPR:
1955 /* Don't warn about values cast to void. */
1956 if (TREE_TYPE (exp) == void_type_node)
1958 /* Don't warn about conversions not explicit in the user's program. */
1959 if (TREE_NO_UNUSED_WARNING (exp))
1961 /* Assignment to a cast usually results in a cast of a modify.
1962 Don't complain about that. There can be an arbitrary number of
1963 casts before the modify, so we must loop until we find the first
1964 non-cast expression and then test to see if that is a modify. */
1966 tree tem = TREE_OPERAND (exp, 0);
1968 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1969 tem = TREE_OPERAND (tem, 0);
1971 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1972 || TREE_CODE (tem) == CALL_EXPR)
1978 /* Don't warn about automatic dereferencing of references, since
1979 the user cannot control it. */
1980 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1981 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1982 /* ... fall through ... */
1985 /* Referencing a volatile value is a side effect, so don't warn. */
1986 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1987 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1988 && TREE_THIS_VOLATILE (exp))
1991 warning_with_file_and_line (emit_filename, emit_lineno,
1992 "value computed is not used");
1997 /* Clear out the memory of the last expression evaluated. */
2005 /* Begin a statement which will return a value.
2006 Return the RTL_EXPR for this statement expr.
2007 The caller must save that value and pass it to expand_end_stmt_expr. */
2010 expand_start_stmt_expr ()
2015 /* Make the RTL_EXPR node temporary, not momentary,
2016 so that rtl_expr_chain doesn't become garbage. */
2017 momentary = suspend_momentary ();
2018 t = make_node (RTL_EXPR);
2019 resume_momentary (momentary);
2020 do_pending_stack_adjust ();
2021 start_sequence_for_rtl_expr (t);
2023 expr_stmts_for_value++;
2027 /* Restore the previous state at the end of a statement that returns a value.
2028 Returns a tree node representing the statement's value and the
2029 insns to compute the value.
2031 The nodes of that expression have been freed by now, so we cannot use them.
2032 But we don't want to do that anyway; the expression has already been
2033 evaluated and now we just want to use the value. So generate a RTL_EXPR
2034 with the proper type and RTL value.
2036 If the last substatement was not an expression,
2037 return something with type `void'. */
2040 expand_end_stmt_expr (t)
2045 if (last_expr_type == 0)
2047 last_expr_type = void_type_node;
2048 last_expr_value = const0_rtx;
2050 else if (last_expr_value == 0)
2051 /* There are some cases where this can happen, such as when the
2052 statement is void type. */
2053 last_expr_value = const0_rtx;
2054 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2055 /* Remove any possible QUEUED. */
2056 last_expr_value = protect_from_queue (last_expr_value, 0);
2060 TREE_TYPE (t) = last_expr_type;
2061 RTL_EXPR_RTL (t) = last_expr_value;
2062 RTL_EXPR_SEQUENCE (t) = get_insns ();
2064 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2068 /* Don't consider deleting this expr or containing exprs at tree level. */
2069 TREE_SIDE_EFFECTS (t) = 1;
2070 /* Propagate volatility of the actual RTL expr. */
2071 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2074 expr_stmts_for_value--;
2079 /* Generate RTL for the start of an if-then. COND is the expression
2080 whose truth should be tested.
2082 If EXITFLAG is nonzero, this conditional is visible to
2083 `exit_something'. */
2086 expand_start_cond (cond, exitflag)
2090 struct nesting *thiscond = ALLOC_NESTING ();
2092 /* Make an entry on cond_stack for the cond we are entering. */
2094 thiscond->next = cond_stack;
2095 thiscond->all = nesting_stack;
2096 thiscond->depth = ++nesting_depth;
2097 thiscond->data.cond.next_label = gen_label_rtx ();
2098 /* Before we encounter an `else', we don't need a separate exit label
2099 unless there are supposed to be exit statements
2100 to exit this conditional. */
2101 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2102 thiscond->data.cond.endif_label = thiscond->exit_label;
2103 cond_stack = thiscond;
2104 nesting_stack = thiscond;
2106 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2109 /* Generate RTL between then-clause and the elseif-clause
2110 of an if-then-elseif-.... */
2113 expand_start_elseif (cond)
2116 if (cond_stack->data.cond.endif_label == 0)
2117 cond_stack->data.cond.endif_label = gen_label_rtx ();
2118 emit_jump (cond_stack->data.cond.endif_label);
2119 emit_label (cond_stack->data.cond.next_label);
2120 cond_stack->data.cond.next_label = gen_label_rtx ();
2121 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2124 /* Generate RTL between the then-clause and the else-clause
2125 of an if-then-else. */
2128 expand_start_else ()
2130 if (cond_stack->data.cond.endif_label == 0)
2131 cond_stack->data.cond.endif_label = gen_label_rtx ();
2133 emit_jump (cond_stack->data.cond.endif_label);
2134 emit_label (cond_stack->data.cond.next_label);
2135 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2138 /* After calling expand_start_else, turn this "else" into an "else if"
2139 by providing another condition. */
2142 expand_elseif (cond)
2145 cond_stack->data.cond.next_label = gen_label_rtx ();
2146 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2149 /* Generate RTL for the end of an if-then.
2150 Pop the record for it off of cond_stack. */
2155 struct nesting *thiscond = cond_stack;
2157 do_pending_stack_adjust ();
2158 if (thiscond->data.cond.next_label)
2159 emit_label (thiscond->data.cond.next_label);
2160 if (thiscond->data.cond.endif_label)
2161 emit_label (thiscond->data.cond.endif_label);
2163 POPSTACK (cond_stack);
2169 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2170 loop should be exited by `exit_something'. This is a loop for which
2171 `expand_continue' will jump to the top of the loop.
2173 Make an entry on loop_stack to record the labels associated with
2177 expand_start_loop (exit_flag)
2180 register struct nesting *thisloop = ALLOC_NESTING ();
2182 /* Make an entry on loop_stack for the loop we are entering. */
2184 thisloop->next = loop_stack;
2185 thisloop->all = nesting_stack;
2186 thisloop->depth = ++nesting_depth;
2187 thisloop->data.loop.start_label = gen_label_rtx ();
2188 thisloop->data.loop.end_label = gen_label_rtx ();
2189 thisloop->data.loop.alt_end_label = 0;
2190 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2191 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2192 loop_stack = thisloop;
2193 nesting_stack = thisloop;
2195 do_pending_stack_adjust ();
2197 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2198 emit_label (thisloop->data.loop.start_label);
2203 /* Like expand_start_loop but for a loop where the continuation point
2204 (for expand_continue_loop) will be specified explicitly. */
2207 expand_start_loop_continue_elsewhere (exit_flag)
2210 struct nesting *thisloop = expand_start_loop (exit_flag);
2211 loop_stack->data.loop.continue_label = gen_label_rtx ();
2215 /* Specify the continuation point for a loop started with
2216 expand_start_loop_continue_elsewhere.
2217 Use this at the point in the code to which a continue statement
2221 expand_loop_continue_here ()
2223 do_pending_stack_adjust ();
2224 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2225 emit_label (loop_stack->data.loop.continue_label);
2228 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2229 Pop the block off of loop_stack. */
2234 rtx start_label = loop_stack->data.loop.start_label;
2235 rtx insn = get_last_insn ();
2236 int needs_end_jump = 1;
2238 /* Mark the continue-point at the top of the loop if none elsewhere. */
2239 if (start_label == loop_stack->data.loop.continue_label)
2240 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2242 do_pending_stack_adjust ();
2244 /* If optimizing, perhaps reorder the loop.
2245 First, try to use a condjump near the end.
2246 expand_exit_loop_if_false ends loops with unconditional jumps,
2249 if (test) goto label;
2251 goto loop_stack->data.loop.end_label
2255 If we find such a pattern, we can end the loop earlier. */
2258 && GET_CODE (insn) == CODE_LABEL
2259 && LABEL_NAME (insn) == NULL
2260 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2263 rtx jump = PREV_INSN (PREV_INSN (label));
2265 if (GET_CODE (jump) == JUMP_INSN
2266 && GET_CODE (PATTERN (jump)) == SET
2267 && SET_DEST (PATTERN (jump)) == pc_rtx
2268 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2269 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2270 == loop_stack->data.loop.end_label))
2274 /* The test might be complex and reference LABEL multiple times,
2275 like the loop in loop_iterations to set vtop. To handle this,
2277 insn = PREV_INSN (label);
2278 reorder_insns (label, label, start_label);
2280 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2282 /* We ignore line number notes, but if we see any other note,
2283 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2284 NOTE_INSN_LOOP_*, we disable this optimization. */
2285 if (GET_CODE (prev) == NOTE)
2287 if (NOTE_LINE_NUMBER (prev) < 0)
2291 if (GET_CODE (prev) == CODE_LABEL)
2293 if (GET_CODE (prev) == JUMP_INSN)
2295 if (GET_CODE (PATTERN (prev)) == SET
2296 && SET_DEST (PATTERN (prev)) == pc_rtx
2297 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2298 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2300 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2302 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2304 emit_note_after (NOTE_INSN_LOOP_END, prev);
2313 /* If the loop starts with a loop exit, roll that to the end where
2314 it will optimize together with the jump back.
2316 We look for the conditional branch to the exit, except that once
2317 we find such a branch, we don't look past 30 instructions.
2319 In more detail, if the loop presently looks like this (in pseudo-C):
2322 if (test) goto end_label;
2327 transform it to look like:
2333 if (test) goto end_label;
2334 goto newstart_label;
2337 Here, the `test' may actually consist of some reasonably complex
2338 code, terminating in a test. */
2343 ! (GET_CODE (insn) == JUMP_INSN
2344 && GET_CODE (PATTERN (insn)) == SET
2345 && SET_DEST (PATTERN (insn)) == pc_rtx
2346 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2350 rtx last_test_insn = NULL_RTX;
2352 /* Scan insns from the top of the loop looking for a qualified
2353 conditional exit. */
2354 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2355 insn = NEXT_INSN (insn))
2357 if (GET_CODE (insn) == NOTE)
2360 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2361 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2362 /* The code that actually moves the exit test will
2363 carefully leave BLOCK notes in their original
2364 location. That means, however, that we can't debug
2365 the exit test itself. So, we refuse to move code
2366 containing BLOCK notes at low optimization levels. */
2369 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2371 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2375 /* We've come to the end of an EH region, but
2376 never saw the beginning of that region. That
2377 means that an EH region begins before the top
2378 of the loop, and ends in the middle of it. The
2379 existence of such a situation violates a basic
2380 assumption in this code, since that would imply
2381 that even when EH_REGIONS is zero, we might
2382 move code out of an exception region. */
2386 /* We must not walk into a nested loop. */
2387 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2390 /* We already know this INSN is a NOTE, so there's no
2391 point in looking at it to see if it's a JUMP. */
2395 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2398 if (last_test_insn && num_insns > 30)
2402 /* We don't want to move a partial EH region. Consider:
2416 This isn't legal C++, but here's what it's supposed to
2417 mean: if cond() is true, stop looping. Otherwise,
2418 call bar, and keep looping. In addition, if cond
2419 throws an exception, catch it and keep looping. Such
2420 constructs are certainy legal in LISP.
2422 We should not move the `if (cond()) 0' test since then
2423 the EH-region for the try-block would be broken up.
2424 (In this case we would the EH_BEG note for the `try'
2425 and `if cond()' but not the call to bar() or the
2428 So we don't look for tests within an EH region. */
2431 if (GET_CODE (insn) == JUMP_INSN
2432 && GET_CODE (PATTERN (insn)) == SET
2433 && SET_DEST (PATTERN (insn)) == pc_rtx)
2435 /* This is indeed a jump. */
2436 rtx dest1 = NULL_RTX;
2437 rtx dest2 = NULL_RTX;
2438 rtx potential_last_test;
2439 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2441 /* A conditional jump. */
2442 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2443 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2444 potential_last_test = insn;
2448 /* An unconditional jump. */
2449 dest1 = SET_SRC (PATTERN (insn));
2450 /* Include the BARRIER after the JUMP. */
2451 potential_last_test = NEXT_INSN (insn);
2455 if (dest1 && GET_CODE (dest1) == LABEL_REF
2456 && ((XEXP (dest1, 0)
2457 == loop_stack->data.loop.alt_end_label)
2459 == loop_stack->data.loop.end_label)))
2461 last_test_insn = potential_last_test;
2465 /* If this was a conditional jump, there may be
2466 another label at which we should look. */
2473 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2475 /* We found one. Move everything from there up
2476 to the end of the loop, and add a jump into the loop
2477 to jump to there. */
2478 register rtx newstart_label = gen_label_rtx ();
2479 register rtx start_move = start_label;
2482 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2483 then we want to move this note also. */
2484 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2485 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2486 == NOTE_INSN_LOOP_CONT))
2487 start_move = PREV_INSN (start_move);
2489 emit_label_after (newstart_label, PREV_INSN (start_move));
2491 /* Actually move the insns. Start at the beginning, and
2492 keep copying insns until we've copied the
2494 for (insn = start_move; insn; insn = next_insn)
2496 /* Figure out which insn comes after this one. We have
2497 to do this before we move INSN. */
2498 if (insn == last_test_insn)
2499 /* We've moved all the insns. */
2500 next_insn = NULL_RTX;
2502 next_insn = NEXT_INSN (insn);
2504 if (GET_CODE (insn) == NOTE
2505 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2506 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2507 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2508 NOTE_INSN_BLOCK_ENDs because the correct generation
2509 of debugging information depends on these appearing
2510 in the same order in the RTL and in the tree
2511 structure, where they are represented as BLOCKs.
2512 So, we don't move block notes. Of course, moving
2513 the code inside the block is likely to make it
2514 impossible to debug the instructions in the exit
2515 test, but such is the price of optimization. */
2518 /* Move the INSN. */
2519 reorder_insns (insn, insn, get_last_insn ());
2522 emit_jump_insn_after (gen_jump (start_label),
2523 PREV_INSN (newstart_label));
2524 emit_barrier_after (PREV_INSN (newstart_label));
2525 start_label = newstart_label;
2531 emit_jump (start_label);
2532 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2534 emit_label (loop_stack->data.loop.end_label);
2536 POPSTACK (loop_stack);
2541 /* Generate a jump to the current loop's continue-point.
2542 This is usually the top of the loop, but may be specified
2543 explicitly elsewhere. If not currently inside a loop,
2544 return 0 and do nothing; caller will print an error message. */
2547 expand_continue_loop (whichloop)
2548 struct nesting *whichloop;
2552 whichloop = loop_stack;
2555 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2560 /* Generate a jump to exit the current loop. If not currently inside a loop,
2561 return 0 and do nothing; caller will print an error message. */
2564 expand_exit_loop (whichloop)
2565 struct nesting *whichloop;
2569 whichloop = loop_stack;
2572 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2576 /* Generate a conditional jump to exit the current loop if COND
2577 evaluates to zero. If not currently inside a loop,
2578 return 0 and do nothing; caller will print an error message. */
2581 expand_exit_loop_if_false (whichloop, cond)
2582 struct nesting *whichloop;
2585 rtx label = gen_label_rtx ();
2590 whichloop = loop_stack;
2593 /* In order to handle fixups, we actually create a conditional jump
2594 around a unconditional branch to exit the loop. If fixups are
2595 necessary, they go before the unconditional branch. */
2598 do_jump (cond, NULL_RTX, label);
2599 last_insn = get_last_insn ();
2600 if (GET_CODE (last_insn) == CODE_LABEL)
2601 whichloop->data.loop.alt_end_label = last_insn;
2602 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2609 /* Return nonzero if the loop nest is empty. Else return zero. */
2612 stmt_loop_nest_empty ()
2614 return (loop_stack == NULL);
2617 /* Return non-zero if we should preserve sub-expressions as separate
2618 pseudos. We never do so if we aren't optimizing. We always do so
2619 if -fexpensive-optimizations.
2621 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2622 the loop may still be a small one. */
2625 preserve_subexpressions_p ()
2629 if (flag_expensive_optimizations)
2632 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2635 insn = get_last_insn_anywhere ();
2638 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2639 < n_non_fixed_regs * 3));
2643 /* Generate a jump to exit the current loop, conditional, binding contour
2644 or case statement. Not all such constructs are visible to this function,
2645 only those started with EXIT_FLAG nonzero. Individual languages use
2646 the EXIT_FLAG parameter to control which kinds of constructs you can
2649 If not currently inside anything that can be exited,
2650 return 0 and do nothing; caller will print an error message. */
2653 expand_exit_something ()
2657 for (n = nesting_stack; n; n = n->all)
2658 if (n->exit_label != 0)
2660 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2667 /* Generate RTL to return from the current function, with no value.
2668 (That is, we do not do anything about returning any value.) */
2671 expand_null_return ()
2673 struct nesting *block = block_stack;
2674 rtx last_insn = get_last_insn ();
2676 /* If this function was declared to return a value, but we
2677 didn't, clobber the return registers so that they are not
2678 propogated live to the rest of the function. */
2679 clobber_return_register ();
2681 /* Does any pending block have cleanups? */
2682 while (block && block->data.block.cleanups == 0)
2683 block = block->next;
2685 /* If yes, use a goto to return, since that runs cleanups. */
2687 expand_null_return_1 (last_insn, block != 0);
2690 /* Generate RTL to return from the current function, with value VAL. */
2693 expand_value_return (val)
2696 struct nesting *block = block_stack;
2697 rtx last_insn = get_last_insn ();
2698 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2700 /* Copy the value to the return location
2701 unless it's already there. */
2703 if (return_reg != val)
2705 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2706 #ifdef PROMOTE_FUNCTION_RETURN
2707 int unsignedp = TREE_UNSIGNED (type);
2708 enum machine_mode old_mode
2709 = DECL_MODE (DECL_RESULT (current_function_decl));
2710 enum machine_mode mode
2711 = promote_mode (type, old_mode, &unsignedp, 1);
2713 if (mode != old_mode)
2714 val = convert_modes (mode, old_mode, val, unsignedp);
2716 if (GET_CODE (return_reg) == PARALLEL)
2717 emit_group_load (return_reg, val, int_size_in_bytes (type),
2718 TYPE_ALIGN (type) / BITS_PER_UNIT);
2720 emit_move_insn (return_reg, val);
2723 /* Does any pending block have cleanups? */
2725 while (block && block->data.block.cleanups == 0)
2726 block = block->next;
2728 /* If yes, use a goto to return, since that runs cleanups.
2729 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2731 expand_null_return_1 (last_insn, block != 0);
2734 /* Output a return with no value. If LAST_INSN is nonzero,
2735 pretend that the return takes place after LAST_INSN.
2736 If USE_GOTO is nonzero then don't use a return instruction;
2737 go to the return label instead. This causes any cleanups
2738 of pending blocks to be executed normally. */
2741 expand_null_return_1 (last_insn, use_goto)
2745 rtx end_label = cleanup_label ? cleanup_label : return_label;
2747 clear_pending_stack_adjust ();
2748 do_pending_stack_adjust ();
2751 /* PCC-struct return always uses an epilogue. */
2752 if (current_function_returns_pcc_struct || use_goto)
2755 end_label = return_label = gen_label_rtx ();
2756 expand_goto_internal (NULL_TREE, end_label, last_insn);
2760 /* Otherwise output a simple return-insn if one is available,
2761 unless it won't do the job. */
2763 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2765 emit_jump_insn (gen_return ());
2771 /* Otherwise jump to the epilogue. */
2772 expand_goto_internal (NULL_TREE, end_label, last_insn);
2775 /* Generate RTL to evaluate the expression RETVAL and return it
2776 from the current function. */
2779 expand_return (retval)
2782 /* If there are any cleanups to be performed, then they will
2783 be inserted following LAST_INSN. It is desirable
2784 that the last_insn, for such purposes, should be the
2785 last insn before computing the return value. Otherwise, cleanups
2786 which call functions can clobber the return value. */
2787 /* ??? rms: I think that is erroneous, because in C++ it would
2788 run destructors on variables that might be used in the subsequent
2789 computation of the return value. */
2791 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2792 register rtx val = 0;
2799 /* If function wants no value, give it none. */
2800 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2802 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2804 expand_null_return ();
2808 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2809 /* This is not sufficient. We also need to watch for cleanups of the
2810 expression we are about to expand. Unfortunately, we cannot know
2811 if it has cleanups until we expand it, and we want to change how we
2812 expand it depending upon if we need cleanups. We can't win. */
2814 cleanups = any_pending_cleanups (1);
2819 if (TREE_CODE (retval) == RESULT_DECL)
2820 retval_rhs = retval;
2821 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2822 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2823 retval_rhs = TREE_OPERAND (retval, 1);
2824 else if (TREE_TYPE (retval) == void_type_node)
2825 /* Recognize tail-recursive call to void function. */
2826 retval_rhs = retval;
2828 retval_rhs = NULL_TREE;
2830 /* Only use `last_insn' if there are cleanups which must be run. */
2831 if (cleanups || cleanup_label != 0)
2832 last_insn = get_last_insn ();
2834 /* Distribute return down conditional expr if either of the sides
2835 may involve tail recursion (see test below). This enhances the number
2836 of tail recursions we see. Don't do this always since it can produce
2837 sub-optimal code in some cases and we distribute assignments into
2838 conditional expressions when it would help. */
2840 if (optimize && retval_rhs != 0
2841 && frame_offset == 0
2842 && TREE_CODE (retval_rhs) == COND_EXPR
2843 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2844 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2846 rtx label = gen_label_rtx ();
2849 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2850 start_cleanup_deferral ();
2851 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2852 DECL_RESULT (current_function_decl),
2853 TREE_OPERAND (retval_rhs, 1));
2854 TREE_SIDE_EFFECTS (expr) = 1;
2855 expand_return (expr);
2858 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2859 DECL_RESULT (current_function_decl),
2860 TREE_OPERAND (retval_rhs, 2));
2861 TREE_SIDE_EFFECTS (expr) = 1;
2862 expand_return (expr);
2863 end_cleanup_deferral ();
2867 /* Attempt to optimize the call if it is tail recursive. */
2868 if (optimize_tail_recursion (retval_rhs, last_insn))
2872 /* This optimization is safe if there are local cleanups
2873 because expand_null_return takes care of them.
2874 ??? I think it should also be safe when there is a cleanup label,
2875 because expand_null_return takes care of them, too.
2876 Any reason why not? */
2877 if (HAVE_return && cleanup_label == 0
2878 && ! current_function_returns_pcc_struct
2879 && BRANCH_COST <= 1)
2881 /* If this is return x == y; then generate
2882 if (x == y) return 1; else return 0;
2883 if we can do it with explicit return insns and branches are cheap,
2884 but not if we have the corresponding scc insn. */
2887 switch (TREE_CODE (retval_rhs))
2913 case TRUTH_ANDIF_EXPR:
2914 case TRUTH_ORIF_EXPR:
2915 case TRUTH_AND_EXPR:
2917 case TRUTH_NOT_EXPR:
2918 case TRUTH_XOR_EXPR:
2921 op0 = gen_label_rtx ();
2922 jumpifnot (retval_rhs, op0);
2923 expand_value_return (const1_rtx);
2925 expand_value_return (const0_rtx);
2934 #endif /* HAVE_return */
2936 /* If the result is an aggregate that is being returned in one (or more)
2937 registers, load the registers here. The compiler currently can't handle
2938 copying a BLKmode value into registers. We could put this code in a
2939 more general area (for use by everyone instead of just function
2940 call/return), but until this feature is generally usable it is kept here
2941 (and in expand_call). The value must go into a pseudo in case there
2942 are cleanups that will clobber the real return register. */
2945 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2946 && GET_CODE (result_rtl) == REG)
2948 int i, bitpos, xbitpos;
2949 int big_endian_correction = 0;
2950 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2951 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2952 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2953 (unsigned int)BITS_PER_WORD);
2954 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2955 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2956 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2957 enum machine_mode tmpmode, result_reg_mode;
2959 /* Structures whose size is not a multiple of a word are aligned
2960 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2961 machine, this means we must skip the empty high order bytes when
2962 calculating the bit offset. */
2963 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2964 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2967 /* Copy the structure BITSIZE bits at a time. */
2968 for (bitpos = 0, xbitpos = big_endian_correction;
2969 bitpos < bytes * BITS_PER_UNIT;
2970 bitpos += bitsize, xbitpos += bitsize)
2972 /* We need a new destination pseudo each time xbitpos is
2973 on a word boundary and when xbitpos == big_endian_correction
2974 (the first time through). */
2975 if (xbitpos % BITS_PER_WORD == 0
2976 || xbitpos == big_endian_correction)
2978 /* Generate an appropriate register. */
2979 dst = gen_reg_rtx (word_mode);
2980 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2982 /* Clobber the destination before we move anything into it. */
2983 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2986 /* We need a new source operand each time bitpos is on a word
2988 if (bitpos % BITS_PER_WORD == 0)
2989 src = operand_subword_force (result_val,
2990 bitpos / BITS_PER_WORD,
2993 /* Use bitpos for the source extraction (left justified) and
2994 xbitpos for the destination store (right justified). */
2995 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2996 extract_bit_field (src, bitsize,
2997 bitpos % BITS_PER_WORD, 1,
2998 NULL_RTX, word_mode,
3000 bitsize / BITS_PER_UNIT,
3002 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
3005 /* Find the smallest integer mode large enough to hold the
3006 entire structure and use that mode instead of BLKmode
3007 on the USE insn for the return register. */
3008 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3009 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3010 tmpmode != VOIDmode;
3011 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3013 /* Have we found a large enough mode? */
3014 if (GET_MODE_SIZE (tmpmode) >= bytes)
3018 /* No suitable mode found. */
3019 if (tmpmode == VOIDmode)
3022 PUT_MODE (result_rtl, tmpmode);
3024 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3025 result_reg_mode = word_mode;
3027 result_reg_mode = tmpmode;
3028 result_reg = gen_reg_rtx (result_reg_mode);
3031 for (i = 0; i < n_regs; i++)
3032 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3035 if (tmpmode != result_reg_mode)
3036 result_reg = gen_lowpart (tmpmode, result_reg);
3038 expand_value_return (result_reg);
3042 && TREE_TYPE (retval_rhs) != void_type_node
3043 && (GET_CODE (result_rtl) == REG
3044 || (GET_CODE (result_rtl) == PARALLEL)))
3046 /* Calculate the return value into a temporary (usually a pseudo
3048 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3050 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3051 val = force_not_mem (val);
3053 /* Return the calculated value, doing cleanups first. */
3054 expand_value_return (val);
3058 /* No cleanups or no hard reg used;
3059 calculate value into hard return reg. */
3060 expand_expr (retval, const0_rtx, VOIDmode, 0);
3062 expand_value_return (result_rtl);
3066 /* Return 1 if the end of the generated RTX is not a barrier.
3067 This means code already compiled can drop through. */
3070 drop_through_at_end_p ()
3072 rtx insn = get_last_insn ();
3073 while (insn && GET_CODE (insn) == NOTE)
3074 insn = PREV_INSN (insn);
3075 return insn && GET_CODE (insn) != BARRIER;
3078 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3079 and emit code to optimize the tail recursion. LAST_INSN indicates where
3080 to place the jump to the tail recursion label. Return TRUE if the
3081 call was optimized into a goto.
3083 This is only used by expand_return, but expand_call is expected to
3087 optimize_tail_recursion (call_expr, last_insn)
3091 /* For tail-recursive call to current function,
3092 just jump back to the beginning.
3093 It's unsafe if any auto variable in this function
3094 has its address taken; for simplicity,
3095 require stack frame to be empty. */
3096 if (optimize && call_expr != 0
3097 && frame_offset == 0
3098 && TREE_CODE (call_expr) == CALL_EXPR
3099 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3100 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3101 /* Finish checking validity, and if valid emit code
3102 to set the argument variables for the new call. */
3103 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3104 DECL_ARGUMENTS (current_function_decl)))
3106 if (tail_recursion_label == 0)
3108 tail_recursion_label = gen_label_rtx ();
3109 emit_label_after (tail_recursion_label,
3110 tail_recursion_reentry);
3113 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3121 /* Emit code to alter this function's formal parms for a tail-recursive call.
3122 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3123 FORMALS is the chain of decls of formals.
3124 Return 1 if this can be done;
3125 otherwise return 0 and do not emit any code. */
3128 tail_recursion_args (actuals, formals)
3129 tree actuals, formals;
3131 register tree a = actuals, f = formals;
3133 register rtx *argvec;
3135 /* Check that number and types of actuals are compatible
3136 with the formals. This is not always true in valid C code.
3137 Also check that no formal needs to be addressable
3138 and that all formals are scalars. */
3140 /* Also count the args. */
3142 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3144 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3145 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3147 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3150 if (a != 0 || f != 0)
3153 /* Compute all the actuals. */
3155 argvec = (rtx *) alloca (i * sizeof (rtx));
3157 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3158 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3160 /* Find which actual values refer to current values of previous formals.
3161 Copy each of them now, before any formal is changed. */
3163 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3167 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3168 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3169 { copy = 1; break; }
3171 argvec[i] = copy_to_reg (argvec[i]);
3174 /* Store the values of the actuals into the formals. */
3176 for (f = formals, a = actuals, i = 0; f;
3177 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3179 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3180 emit_move_insn (DECL_RTL (f), argvec[i]);
3182 convert_move (DECL_RTL (f), argvec[i],
3183 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3190 /* Generate the RTL code for entering a binding contour.
3191 The variables are declared one by one, by calls to `expand_decl'.
3193 FLAGS is a bitwise or of the following flags:
3195 1 - Nonzero if this construct should be visible to
3198 2 - Nonzero if this contour does not require a
3199 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3200 language-independent code should set this flag because they
3201 will not create corresponding BLOCK nodes. (There should be
3202 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3203 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3204 when expand_end_bindings is called.
3206 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3207 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3211 expand_start_bindings_and_block (flags, block)
3215 struct nesting *thisblock = ALLOC_NESTING ();
3217 int exit_flag = ((flags & 1) != 0);
3218 int block_flag = ((flags & 2) == 0);
3220 /* If a BLOCK is supplied, then the caller should be requesting a
3221 NOTE_INSN_BLOCK_BEG note. */
3222 if (!block_flag && block)
3225 /* Create a note to mark the beginning of the block. */
3228 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3229 NOTE_BLOCK (note) = block;
3232 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3234 /* Make an entry on block_stack for the block we are entering. */
3236 thisblock->next = block_stack;
3237 thisblock->all = nesting_stack;
3238 thisblock->depth = ++nesting_depth;
3239 thisblock->data.block.stack_level = 0;
3240 thisblock->data.block.cleanups = 0;
3241 thisblock->data.block.n_function_calls = 0;
3242 thisblock->data.block.exception_region = 0;
3243 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3245 thisblock->data.block.conditional_code = 0;
3246 thisblock->data.block.last_unconditional_cleanup = note;
3247 /* When we insert instructions after the last unconditional cleanup,
3248 we don't adjust last_insn. That means that a later add_insn will
3249 clobber the instructions we've just added. The easiest way to
3250 fix this is to just insert another instruction here, so that the
3251 instructions inserted after the last unconditional cleanup are
3252 never the last instruction. */
3253 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3254 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3257 && !(block_stack->data.block.cleanups == NULL_TREE
3258 && block_stack->data.block.outer_cleanups == NULL_TREE))
3259 thisblock->data.block.outer_cleanups
3260 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3261 block_stack->data.block.outer_cleanups);
3263 thisblock->data.block.outer_cleanups = 0;
3264 thisblock->data.block.label_chain = 0;
3265 thisblock->data.block.innermost_stack_block = stack_block_stack;
3266 thisblock->data.block.first_insn = note;
3267 thisblock->data.block.block_start_count = ++current_block_start_count;
3268 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3269 block_stack = thisblock;
3270 nesting_stack = thisblock;
3272 /* Make a new level for allocating stack slots. */
3276 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3277 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3278 expand_expr are made. After we end the region, we know that all
3279 space for all temporaries that were created by TARGET_EXPRs will be
3280 destroyed and their space freed for reuse. */
3283 expand_start_target_temps ()
3285 /* This is so that even if the result is preserved, the space
3286 allocated will be freed, as we know that it is no longer in use. */
3289 /* Start a new binding layer that will keep track of all cleanup
3290 actions to be performed. */
3291 expand_start_bindings (2);
3293 target_temp_slot_level = temp_slot_level;
3297 expand_end_target_temps ()
3299 expand_end_bindings (NULL_TREE, 0, 0);
3301 /* This is so that even if the result is preserved, the space
3302 allocated will be freed, as we know that it is no longer in use. */
3306 /* Mark top block of block_stack as an implicit binding for an
3307 exception region. This is used to prevent infinite recursion when
3308 ending a binding with expand_end_bindings. It is only ever called
3309 by expand_eh_region_start, as that it the only way to create a
3310 block stack for a exception region. */
3313 mark_block_as_eh_region ()
3315 block_stack->data.block.exception_region = 1;
3316 if (block_stack->next
3317 && block_stack->next->data.block.conditional_code)
3319 block_stack->data.block.conditional_code
3320 = block_stack->next->data.block.conditional_code;
3321 block_stack->data.block.last_unconditional_cleanup
3322 = block_stack->next->data.block.last_unconditional_cleanup;
3323 block_stack->data.block.cleanup_ptr
3324 = block_stack->next->data.block.cleanup_ptr;
3328 /* True if we are currently emitting insns in an area of output code
3329 that is controlled by a conditional expression. This is used by
3330 the cleanup handling code to generate conditional cleanup actions. */
3333 conditional_context ()
3335 return block_stack && block_stack->data.block.conditional_code;
3338 /* Mark top block of block_stack as not for an implicit binding for an
3339 exception region. This is only ever done by expand_eh_region_end
3340 to let expand_end_bindings know that it is being called explicitly
3341 to end the binding layer for just the binding layer associated with
3342 the exception region, otherwise expand_end_bindings would try and
3343 end all implicit binding layers for exceptions regions, and then
3344 one normal binding layer. */
3347 mark_block_as_not_eh_region ()
3349 block_stack->data.block.exception_region = 0;
3352 /* True if the top block of block_stack was marked as for an exception
3353 region by mark_block_as_eh_region. */
3358 return cfun && block_stack && block_stack->data.block.exception_region;
3361 /* Emit a handler label for a nonlocal goto handler.
3362 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3365 expand_nl_handler_label (slot, before_insn)
3366 rtx slot, before_insn;
3369 rtx handler_label = gen_label_rtx ();
3371 /* Don't let jump_optimize delete the handler. */
3372 LABEL_PRESERVE_P (handler_label) = 1;
3375 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3376 insns = get_insns ();
3378 emit_insns_before (insns, before_insn);
3380 emit_label (handler_label);
3382 return handler_label;
3385 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3388 expand_nl_goto_receiver ()
3390 #ifdef HAVE_nonlocal_goto
3391 if (! HAVE_nonlocal_goto)
3393 /* First adjust our frame pointer to its actual value. It was
3394 previously set to the start of the virtual area corresponding to
3395 the stacked variables when we branched here and now needs to be
3396 adjusted to the actual hardware fp value.
3398 Assignments are to virtual registers are converted by
3399 instantiate_virtual_regs into the corresponding assignment
3400 to the underlying register (fp in this case) that makes
3401 the original assignment true.
3402 So the following insn will actually be
3403 decrementing fp by STARTING_FRAME_OFFSET. */
3404 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3406 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3407 if (fixed_regs[ARG_POINTER_REGNUM])
3409 #ifdef ELIMINABLE_REGS
3410 /* If the argument pointer can be eliminated in favor of the
3411 frame pointer, we don't need to restore it. We assume here
3412 that if such an elimination is present, it can always be used.
3413 This is the case on all known machines; if we don't make this
3414 assumption, we do unnecessary saving on many machines. */
3415 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3418 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3419 if (elim_regs[i].from == ARG_POINTER_REGNUM
3420 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3423 if (i == sizeof elim_regs / sizeof elim_regs [0])
3426 /* Now restore our arg pointer from the address at which it
3427 was saved in our stack frame.
3428 If there hasn't be space allocated for it yet, make
3430 if (arg_pointer_save_area == 0)
3431 arg_pointer_save_area
3432 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3433 emit_move_insn (virtual_incoming_args_rtx,
3434 /* We need a pseudo here, or else
3435 instantiate_virtual_regs_1 complains. */
3436 copy_to_reg (arg_pointer_save_area));
3441 #ifdef HAVE_nonlocal_goto_receiver
3442 if (HAVE_nonlocal_goto_receiver)
3443 emit_insn (gen_nonlocal_goto_receiver ());
3447 /* Make handlers for nonlocal gotos taking place in the function calls in
3451 expand_nl_goto_receivers (thisblock)
3452 struct nesting *thisblock;
3455 rtx afterward = gen_label_rtx ();
3460 /* Record the handler address in the stack slot for that purpose,
3461 during this block, saving and restoring the outer value. */
3462 if (thisblock->next != 0)
3463 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3465 rtx save_receiver = gen_reg_rtx (Pmode);
3466 emit_move_insn (XEXP (slot, 0), save_receiver);
3469 emit_move_insn (save_receiver, XEXP (slot, 0));
3470 insns = get_insns ();
3472 emit_insns_before (insns, thisblock->data.block.first_insn);
3475 /* Jump around the handlers; they run only when specially invoked. */
3476 emit_jump (afterward);
3478 /* Make a separate handler for each label. */
3479 link = nonlocal_labels;
3480 slot = nonlocal_goto_handler_slots;
3481 label_list = NULL_RTX;
3482 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3483 /* Skip any labels we shouldn't be able to jump to from here,
3484 we generate one special handler for all of them below which just calls
3486 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3489 lab = expand_nl_handler_label (XEXP (slot, 0),
3490 thisblock->data.block.first_insn);
3491 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3493 expand_nl_goto_receiver ();
3495 /* Jump to the "real" nonlocal label. */
3496 expand_goto (TREE_VALUE (link));
3499 /* A second pass over all nonlocal labels; this time we handle those
3500 we should not be able to jump to at this point. */
3501 link = nonlocal_labels;
3502 slot = nonlocal_goto_handler_slots;
3504 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3505 if (DECL_TOO_LATE (TREE_VALUE (link)))
3508 lab = expand_nl_handler_label (XEXP (slot, 0),
3509 thisblock->data.block.first_insn);
3510 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3516 expand_nl_goto_receiver ();
3517 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3522 nonlocal_goto_handler_labels = label_list;
3523 emit_label (afterward);
3526 /* Warn about any unused VARS (which may contain nodes other than
3527 VAR_DECLs, but such nodes are ignored). The nodes are connected
3528 via the TREE_CHAIN field. */
3531 warn_about_unused_variables (vars)
3537 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3538 if (TREE_CODE (decl) == VAR_DECL
3539 && ! TREE_USED (decl)
3540 && ! DECL_IN_SYSTEM_HEADER (decl)
3541 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3542 warning_with_decl (decl, "unused variable `%s'");
3545 /* Generate RTL code to terminate a binding contour.
3547 VARS is the chain of VAR_DECL nodes for the variables bound in this
3548 contour. There may actually be other nodes in this chain, but any
3549 nodes other than VAR_DECLS are ignored.
3551 MARK_ENDS is nonzero if we should put a note at the beginning
3552 and end of this binding contour.
3554 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3555 (That is true automatically if the contour has a saved stack level.) */
3558 expand_end_bindings (vars, mark_ends, dont_jump_in)
3563 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. */
3680 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3681 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3684 /* Get rid of the beginning-mark if we don't make an end-mark. */
3685 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3687 /* Restore the temporary level of TARGET_EXPRs. */
3688 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3690 /* Restore block_stack level for containing block. */
3692 stack_block_stack = thisblock->data.block.innermost_stack_block;
3693 POPSTACK (block_stack);
3695 /* Pop the stack slot nesting and free any slots at this level. */
3699 /* Generate RTL for the automatic variable declaration DECL.
3700 (Other kinds of declarations are simply ignored if seen here.) */
3706 struct nesting *thisblock;
3709 type = TREE_TYPE (decl);
3711 /* Only automatic variables need any expansion done.
3712 Static and external variables, and external functions,
3713 will be handled by `assemble_variable' (called from finish_decl).
3714 TYPE_DECL and CONST_DECL require nothing.
3715 PARM_DECLs are handled in `assign_parms'. */
3717 if (TREE_CODE (decl) != VAR_DECL)
3719 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3722 thisblock = block_stack;
3724 /* Create the RTL representation for the variable. */
3726 if (type == error_mark_node)
3727 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3728 else if (DECL_SIZE (decl) == 0)
3729 /* Variable with incomplete type. */
3731 if (DECL_INITIAL (decl) == 0)
3732 /* Error message was already done; now avoid a crash. */
3733 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3735 /* An initializer is going to decide the size of this array.
3736 Until we know the size, represent its address with a reg. */
3737 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3738 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3740 else if (DECL_MODE (decl) != BLKmode
3741 /* If -ffloat-store, don't put explicit float vars
3743 && !(flag_float_store
3744 && TREE_CODE (type) == REAL_TYPE)
3745 && ! TREE_THIS_VOLATILE (decl)
3746 && ! TREE_ADDRESSABLE (decl)
3747 && (DECL_REGISTER (decl) || optimize)
3748 /* if -fcheck-memory-usage, check all variables. */
3749 && ! current_function_check_memory_usage)
3751 /* Automatic variable that can go in a register. */
3752 int unsignedp = TREE_UNSIGNED (type);
3753 enum machine_mode reg_mode
3754 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3756 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3757 mark_user_reg (DECL_RTL (decl));
3759 if (POINTER_TYPE_P (type))
3760 mark_reg_pointer (DECL_RTL (decl),
3761 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3765 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3766 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3767 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3768 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3769 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3771 /* Variable of fixed size that goes on the stack. */
3775 /* If we previously made RTL for this decl, it must be an array
3776 whose size was determined by the initializer.
3777 The old address was a register; set that register now
3778 to the proper address. */
3779 if (DECL_RTL (decl) != 0)
3781 if (GET_CODE (DECL_RTL (decl)) != MEM
3782 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3784 oldaddr = XEXP (DECL_RTL (decl), 0);
3787 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3788 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3789 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3791 /* Set alignment we actually gave this decl. */
3792 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3793 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3797 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3798 if (addr != oldaddr)
3799 emit_move_insn (oldaddr, addr);
3802 /* If this is a memory ref that contains aggregate components,
3803 mark it as such for cse and loop optimize. */
3804 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3805 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3807 /* If this is in memory because of -ffloat-store,
3808 set the volatile bit, to prevent optimizations from
3809 undoing the effects. */
3810 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3811 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3814 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3817 /* Dynamic-size object: must push space on the stack. */
3821 /* Record the stack pointer on entry to block, if have
3822 not already done so. */
3823 if (thisblock->data.block.stack_level == 0)
3825 do_pending_stack_adjust ();
3826 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3827 &thisblock->data.block.stack_level,
3828 thisblock->data.block.first_insn);
3829 stack_block_stack = thisblock;
3832 /* In function-at-a-time mode, variable_size doesn't expand this,
3834 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3835 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3836 const0_rtx, VOIDmode, 0);
3838 /* Compute the variable's size, in bytes. */
3839 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3841 size_int (BITS_PER_UNIT)),
3842 NULL_RTX, VOIDmode, 0);
3845 /* Allocate space on the stack for the variable. Note that
3846 DECL_ALIGN says how the variable is to be aligned and we
3847 cannot use it to conclude anything about the alignment of
3849 address = allocate_dynamic_stack_space (size, NULL_RTX,
3850 TYPE_ALIGN (TREE_TYPE (decl)));
3852 /* Reference the variable indirect through that rtx. */
3853 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3855 /* If this is a memory ref that contains aggregate components,
3856 mark it as such for cse and loop optimize. */
3857 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3858 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3860 /* Indicate the alignment we actually gave this variable. */
3861 #ifdef STACK_BOUNDARY
3862 DECL_ALIGN (decl) = STACK_BOUNDARY;
3864 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3868 if (TREE_THIS_VOLATILE (decl))
3869 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3871 if (TREE_READONLY (decl))
3872 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3875 /* Emit code to perform the initialization of a declaration DECL. */
3878 expand_decl_init (decl)
3881 int was_used = TREE_USED (decl);
3883 /* If this is a CONST_DECL, we don't have to generate any code, but
3884 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3885 to be set while in the obstack containing the constant. If we don't
3886 do this, we can lose if we have functions nested three deep and the middle
3887 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3888 the innermost function is the first to expand that STRING_CST. */
3889 if (TREE_CODE (decl) == CONST_DECL)
3891 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3892 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3893 EXPAND_INITIALIZER);
3897 if (TREE_STATIC (decl))
3900 /* Compute and store the initial value now. */
3902 if (DECL_INITIAL (decl) == error_mark_node)
3904 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3906 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3907 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3908 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3912 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3914 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3915 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3919 /* Don't let the initialization count as "using" the variable. */
3920 TREE_USED (decl) = was_used;
3922 /* Free any temporaries we made while initializing the decl. */
3923 preserve_temp_slots (NULL_RTX);
3927 /* CLEANUP is an expression to be executed at exit from this binding contour;
3928 for example, in C++, it might call the destructor for this variable.
3930 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3931 CLEANUP multiple times, and have the correct semantics. This
3932 happens in exception handling, for gotos, returns, breaks that
3933 leave the current scope.
3935 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3936 that is not associated with any particular variable. */
3939 expand_decl_cleanup (decl, cleanup)
3942 struct nesting *thisblock;
3944 /* Error if we are not in any block. */
3945 if (cfun == 0 || block_stack == 0)
3948 thisblock = block_stack;
3950 /* Record the cleanup if there is one. */
3956 tree *cleanups = &thisblock->data.block.cleanups;
3957 int cond_context = conditional_context ();
3961 rtx flag = gen_reg_rtx (word_mode);
3966 emit_move_insn (flag, const0_rtx);
3967 set_flag_0 = get_insns ();
3970 thisblock->data.block.last_unconditional_cleanup
3971 = emit_insns_after (set_flag_0,
3972 thisblock->data.block.last_unconditional_cleanup);
3974 emit_move_insn (flag, const1_rtx);
3976 /* All cleanups must be on the function_obstack. */
3977 push_obstacks_nochange ();
3978 resume_temporary_allocation ();
3980 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3981 DECL_RTL (cond) = flag;
3983 /* Conditionalize the cleanup. */
3984 cleanup = build (COND_EXPR, void_type_node,
3985 truthvalue_conversion (cond),
3986 cleanup, integer_zero_node);
3987 cleanup = fold (cleanup);
3991 cleanups = thisblock->data.block.cleanup_ptr;
3994 /* All cleanups must be on the function_obstack. */
3995 push_obstacks_nochange ();
3996 resume_temporary_allocation ();
3997 cleanup = unsave_expr (cleanup);
4000 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4003 /* If this block has a cleanup, it belongs in stack_block_stack. */
4004 stack_block_stack = thisblock;
4011 /* If this was optimized so that there is no exception region for the
4012 cleanup, then mark the TREE_LIST node, so that we can later tell
4013 if we need to call expand_eh_region_end. */
4014 if (! using_eh_for_cleanups_p
4015 || expand_eh_region_start_tree (decl, cleanup))
4016 TREE_ADDRESSABLE (t) = 1;
4017 /* If that started a new EH region, we're in a new block. */
4018 thisblock = block_stack;
4025 thisblock->data.block.last_unconditional_cleanup
4026 = emit_insns_after (seq,
4027 thisblock->data.block.last_unconditional_cleanup);
4031 thisblock->data.block.last_unconditional_cleanup
4033 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4039 /* Like expand_decl_cleanup, but suppress generating an exception handler
4040 to perform the cleanup. */
4044 expand_decl_cleanup_no_eh (decl, cleanup)
4047 int save_eh = using_eh_for_cleanups_p;
4050 using_eh_for_cleanups_p = 0;
4051 result = expand_decl_cleanup (decl, cleanup);
4052 using_eh_for_cleanups_p = save_eh;
4058 /* Arrange for the top element of the dynamic cleanup chain to be
4059 popped if we exit the current binding contour. DECL is the
4060 associated declaration, if any, otherwise NULL_TREE. If the
4061 current contour is left via an exception, then __sjthrow will pop
4062 the top element off the dynamic cleanup chain. The code that
4063 avoids doing the action we push into the cleanup chain in the
4064 exceptional case is contained in expand_cleanups.
4066 This routine is only used by expand_eh_region_start, and that is
4067 the only way in which an exception region should be started. This
4068 routine is only used when using the setjmp/longjmp codegen method
4069 for exception handling. */
4072 expand_dcc_cleanup (decl)
4075 struct nesting *thisblock;
4078 /* Error if we are not in any block. */
4079 if (cfun == 0 || block_stack == 0)
4081 thisblock = block_stack;
4083 /* Record the cleanup for the dynamic handler chain. */
4085 /* All cleanups must be on the function_obstack. */
4086 push_obstacks_nochange ();
4087 resume_temporary_allocation ();
4088 cleanup = make_node (POPDCC_EXPR);
4091 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4092 thisblock->data.block.cleanups
4093 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4095 /* If this block has a cleanup, it belongs in stack_block_stack. */
4096 stack_block_stack = thisblock;
4100 /* Arrange for the top element of the dynamic handler chain to be
4101 popped if we exit the current binding contour. DECL is the
4102 associated declaration, if any, otherwise NULL_TREE. If the current
4103 contour is left via an exception, then __sjthrow will pop the top
4104 element off the dynamic handler chain. The code that avoids doing
4105 the action we push into the handler chain in the exceptional case
4106 is contained in expand_cleanups.
4108 This routine is only used by expand_eh_region_start, and that is
4109 the only way in which an exception region should be started. This
4110 routine is only used when using the setjmp/longjmp codegen method
4111 for exception handling. */
4114 expand_dhc_cleanup (decl)
4117 struct nesting *thisblock;
4120 /* Error if we are not in any block. */
4121 if (cfun == 0 || block_stack == 0)
4123 thisblock = block_stack;
4125 /* Record the cleanup for the dynamic handler chain. */
4127 /* All cleanups must be on the function_obstack. */
4128 push_obstacks_nochange ();
4129 resume_temporary_allocation ();
4130 cleanup = make_node (POPDHC_EXPR);
4133 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4134 thisblock->data.block.cleanups
4135 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4137 /* If this block has a cleanup, it belongs in stack_block_stack. */
4138 stack_block_stack = thisblock;
4142 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4143 DECL_ELTS is the list of elements that belong to DECL's type.
4144 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4147 expand_anon_union_decl (decl, cleanup, decl_elts)
4148 tree decl, cleanup, decl_elts;
4150 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4154 /* If any of the elements are addressable, so is the entire union. */
4155 for (t = decl_elts; t; t = TREE_CHAIN (t))
4156 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4158 TREE_ADDRESSABLE (decl) = 1;
4163 expand_decl_cleanup (decl, cleanup);
4164 x = DECL_RTL (decl);
4166 /* Go through the elements, assigning RTL to each. */
4167 for (t = decl_elts; t; t = TREE_CHAIN (t))
4169 tree decl_elt = TREE_VALUE (t);
4170 tree cleanup_elt = TREE_PURPOSE (t);
4171 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4173 /* Propagate the union's alignment to the elements. */
4174 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4176 /* If the element has BLKmode and the union doesn't, the union is
4177 aligned such that the element doesn't need to have BLKmode, so
4178 change the element's mode to the appropriate one for its size. */
4179 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4180 DECL_MODE (decl_elt) = mode
4181 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
4184 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4185 instead create a new MEM rtx with the proper mode. */
4186 if (GET_CODE (x) == MEM)
4188 if (mode == GET_MODE (x))
4189 DECL_RTL (decl_elt) = x;
4192 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4193 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4194 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4197 else if (GET_CODE (x) == REG)
4199 if (mode == GET_MODE (x))
4200 DECL_RTL (decl_elt) = x;
4202 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4207 /* Record the cleanup if there is one. */
4210 thisblock->data.block.cleanups
4211 = temp_tree_cons (decl_elt, cleanup_elt,
4212 thisblock->data.block.cleanups);
4216 /* Expand a list of cleanups LIST.
4217 Elements may be expressions or may be nested lists.
4219 If DONT_DO is nonnull, then any list-element
4220 whose TREE_PURPOSE matches DONT_DO is omitted.
4221 This is sometimes used to avoid a cleanup associated with
4222 a value that is being returned out of the scope.
4224 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4225 goto and handle protection regions specially in that case.
4227 If REACHABLE, we emit code, otherwise just inform the exception handling
4228 code about this finalization. */
4231 expand_cleanups (list, dont_do, in_fixup, reachable)
4238 for (tail = list; tail; tail = TREE_CHAIN (tail))
4239 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4241 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4242 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4247 tree cleanup = TREE_VALUE (tail);
4249 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4250 if (TREE_CODE (cleanup) != POPDHC_EXPR
4251 && TREE_CODE (cleanup) != POPDCC_EXPR
4252 /* See expand_eh_region_start_tree for this case. */
4253 && ! TREE_ADDRESSABLE (tail))
4255 cleanup = protect_with_terminate (cleanup);
4256 expand_eh_region_end (cleanup);
4262 /* Cleanups may be run multiple times. For example,
4263 when exiting a binding contour, we expand the
4264 cleanups associated with that contour. When a goto
4265 within that binding contour has a target outside that
4266 contour, it will expand all cleanups from its scope to
4267 the target. Though the cleanups are expanded multiple
4268 times, the control paths are non-overlapping so the
4269 cleanups will not be executed twice. */
4271 /* We may need to protect fixups with rethrow regions. */
4272 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4275 expand_fixup_region_start ();
4277 /* The cleanup might contain try-blocks, so we have to
4278 preserve our current queue. */
4280 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4283 expand_fixup_region_end (TREE_VALUE (tail));
4290 /* Mark when the context we are emitting RTL for as a conditional
4291 context, so that any cleanup actions we register with
4292 expand_decl_init will be properly conditionalized when those
4293 cleanup actions are later performed. Must be called before any
4294 expression (tree) is expanded that is within a conditional context. */
4297 start_cleanup_deferral ()
4299 /* block_stack can be NULL if we are inside the parameter list. It is
4300 OK to do nothing, because cleanups aren't possible here. */
4302 ++block_stack->data.block.conditional_code;
4305 /* Mark the end of a conditional region of code. Because cleanup
4306 deferrals may be nested, we may still be in a conditional region
4307 after we end the currently deferred cleanups, only after we end all
4308 deferred cleanups, are we back in unconditional code. */
4311 end_cleanup_deferral ()
4313 /* block_stack can be NULL if we are inside the parameter list. It is
4314 OK to do nothing, because cleanups aren't possible here. */
4316 --block_stack->data.block.conditional_code;
4319 /* Move all cleanups from the current block_stack
4320 to the containing block_stack, where they are assumed to
4321 have been created. If anything can cause a temporary to
4322 be created, but not expanded for more than one level of
4323 block_stacks, then this code will have to change. */
4328 struct nesting *block = block_stack;
4329 struct nesting *outer = block->next;
4331 outer->data.block.cleanups
4332 = chainon (block->data.block.cleanups,
4333 outer->data.block.cleanups);
4334 block->data.block.cleanups = 0;
4338 last_cleanup_this_contour ()
4340 if (block_stack == 0)
4343 return block_stack->data.block.cleanups;
4346 /* Return 1 if there are any pending cleanups at this point.
4347 If THIS_CONTOUR is nonzero, check the current contour as well.
4348 Otherwise, look only at the contours that enclose this one. */
4351 any_pending_cleanups (this_contour)
4354 struct nesting *block;
4356 if (cfun == NULL || cfun->stmt == NULL || 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) PARAMS ((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). */
4554 && (TREE_CONSTANT_OVERFLOW (value)
4555 || ! int_fits_type_p (value, index_type)))
4558 /* Fail if this is a duplicate or overlaps another entry. */
4561 if (case_stack->data.case_stmt.default_label != 0)
4563 *duplicate = case_stack->data.case_stmt.default_label;
4566 case_stack->data.case_stmt.default_label = label;
4569 return add_case_node (value, value, label, duplicate);
4571 expand_label (label);
4575 /* Like pushcase but this case applies to all values between VALUE1 and
4576 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4577 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4578 starts at VALUE1 and ends at the highest value of the index type.
4579 If both are NULL, this case applies to all values.
4581 The return value is the same as that of pushcase but there is one
4582 additional error code: 4 means the specified range was empty. */
4585 pushcase_range (value1, value2, converter, label, duplicate)
4586 register tree value1, value2;
4587 tree (*converter) PARAMS ((tree, tree));
4588 register tree label;
4594 /* Fail if not inside a real case statement. */
4595 if (! (case_stack && case_stack->data.case_stmt.start))
4598 if (stack_block_stack
4599 && stack_block_stack->depth > case_stack->depth)
4602 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4603 nominal_type = case_stack->data.case_stmt.nominal_type;
4605 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4606 if (index_type == error_mark_node)
4611 /* Convert VALUEs to type in which the comparisons are nominally done
4612 and replace any unspecified value with the corresponding bound. */
4614 value1 = TYPE_MIN_VALUE (index_type);
4616 value2 = TYPE_MAX_VALUE (index_type);
4618 /* Fail if the range is empty. Do this before any conversion since
4619 we want to allow out-of-range empty ranges. */
4620 if (value2 != 0 && tree_int_cst_lt (value2, 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);
4629 value1 = (*converter) (nominal_type, value1);
4630 value2 = (*converter) (nominal_type, value2);
4632 /* Fail if these values are out of range. */
4633 if (TREE_CONSTANT_OVERFLOW (value1)
4634 || ! int_fits_type_p (value1, index_type))
4637 if (TREE_CONSTANT_OVERFLOW (value2)
4638 || ! int_fits_type_p (value2, index_type))
4641 return add_case_node (value1, value2, label, duplicate);
4644 /* Do the actual insertion of a case label for pushcase and pushcase_range
4645 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4646 slowdown for large switch statements. */
4649 add_case_node (low, high, label, duplicate)
4654 struct case_node *p, **q, *r;
4656 q = &case_stack->data.case_stmt.case_list;
4663 /* Keep going past elements distinctly greater than HIGH. */
4664 if (tree_int_cst_lt (high, p->low))
4667 /* or distinctly less than LOW. */
4668 else if (tree_int_cst_lt (p->high, low))
4673 /* We have an overlap; this is an error. */
4674 *duplicate = p->code_label;
4679 /* Add this label to the chain, and succeed.
4680 Copy LOW, HIGH so they are on temporary rather than momentary
4681 obstack and will thus survive till the end of the case statement. */
4683 r = (struct case_node *) oballoc (sizeof (struct case_node));
4684 r->low = copy_node (low);
4686 /* If the bounds are equal, turn this into the one-value case. */
4688 if (tree_int_cst_equal (low, high))
4692 r->high = copy_node (high);
4693 case_stack->data.case_stmt.num_ranges++;
4696 r->code_label = label;
4697 expand_label (label);
4707 struct case_node *s;
4713 if (! (b = p->balance))
4714 /* Growth propagation from left side. */
4721 if ((p->left = s = r->right))
4730 if ((r->parent = s))
4738 case_stack->data.case_stmt.case_list = r;
4741 /* r->balance == +1 */
4746 struct case_node *t = r->right;
4748 if ((p->left = s = t->right))
4752 if ((r->right = s = t->left))
4766 if ((t->parent = s))
4774 case_stack->data.case_stmt.case_list = t;
4781 /* p->balance == +1; growth of left side balances the node. */
4791 if (! (b = p->balance))
4792 /* Growth propagation from right side. */
4800 if ((p->right = s = r->left))
4808 if ((r->parent = s))
4817 case_stack->data.case_stmt.case_list = r;
4821 /* r->balance == -1 */
4825 struct case_node *t = r->left;
4827 if ((p->right = s = t->left))
4832 if ((r->left = s = t->right))
4846 if ((t->parent = s))
4855 case_stack->data.case_stmt.case_list = t;
4861 /* p->balance == -1; growth of right side balances the node. */
4875 /* Returns the number of possible values of TYPE.
4876 Returns -1 if the number is unknown or variable.
4877 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4878 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4879 do not increase monotonically (there may be duplicates);
4880 to 1 if the values increase monotonically, but not always by 1;
4881 otherwise sets it to 0. */
4884 all_cases_count (type, spareness)
4888 HOST_WIDE_INT count;
4891 switch (TREE_CODE (type))
4898 count = 1 << BITS_PER_UNIT;
4902 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4903 || TYPE_MAX_VALUE (type) == NULL
4904 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4909 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4910 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4911 but with overflow checking. */
4912 tree mint = TYPE_MIN_VALUE (type);
4913 tree maxt = TYPE_MAX_VALUE (type);
4914 HOST_WIDE_INT lo, hi;
4915 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4917 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4919 add_double (lo, hi, 1, 0, &lo, &hi);
4920 if (hi != 0 || lo < 0)
4927 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4929 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4930 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4931 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4932 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4936 if (*spareness == 1)
4938 tree prev = TREE_VALUE (TYPE_VALUES (type));
4939 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4941 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4946 prev = TREE_VALUE (t);
4955 #define BITARRAY_TEST(ARRAY, INDEX) \
4956 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4957 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4958 #define BITARRAY_SET(ARRAY, INDEX) \
4959 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4960 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4962 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4963 with the case values we have seen, assuming the case expression
4965 SPARSENESS is as determined by all_cases_count.
4967 The time needed is proportional to COUNT, unless
4968 SPARSENESS is 2, in which case quadratic time is needed. */
4971 mark_seen_cases (type, cases_seen, count, sparseness)
4973 unsigned char *cases_seen;
4977 tree next_node_to_try = NULL_TREE;
4978 long next_node_offset = 0;
4980 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4981 tree val = make_node (INTEGER_CST);
4982 TREE_TYPE (val) = type;
4985 else if (sparseness == 2)
4990 /* This less efficient loop is only needed to handle
4991 duplicate case values (multiple enum constants
4992 with the same value). */
4993 TREE_TYPE (val) = TREE_TYPE (root->low);
4994 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4995 t = TREE_CHAIN (t), xlo++)
4997 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4998 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5002 /* Keep going past elements distinctly greater than VAL. */
5003 if (tree_int_cst_lt (val, n->low))
5006 /* or distinctly less than VAL. */
5007 else if (tree_int_cst_lt (n->high, val))
5012 /* We have found a matching range. */
5013 BITARRAY_SET (cases_seen, xlo);
5023 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5024 for (n = root; n; n = n->right)
5026 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5027 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5028 while ( ! tree_int_cst_lt (n->high, val))
5030 /* Calculate (into xlo) the "offset" of the integer (val).
5031 The element with lowest value has offset 0, the next smallest
5032 element has offset 1, etc. */
5034 HOST_WIDE_INT xlo, xhi;
5036 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5038 /* The TYPE_VALUES will be in increasing order, so
5039 starting searching where we last ended. */
5040 t = next_node_to_try;
5041 xlo = next_node_offset;
5047 t = TYPE_VALUES (type);
5050 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5052 next_node_to_try = TREE_CHAIN (t);
5053 next_node_offset = xlo + 1;
5058 if (t == next_node_to_try)
5067 t = TYPE_MIN_VALUE (type);
5069 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5073 add_double (xlo, xhi,
5074 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5078 if (xhi == 0 && xlo >= 0 && xlo < count)
5079 BITARRAY_SET (cases_seen, xlo);
5080 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5082 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5088 /* Called when the index of a switch statement is an enumerated type
5089 and there is no default label.
5091 Checks that all enumeration literals are covered by the case
5092 expressions of a switch. Also, warn if there are any extra
5093 switch cases that are *not* elements of the enumerated type.
5095 If all enumeration literals were covered by the case expressions,
5096 turn one of the expressions into the default expression since it should
5097 not be possible to fall through such a switch. */
5100 check_for_full_enumeration_handling (type)
5103 register struct case_node *n;
5104 register tree chain;
5105 #if 0 /* variable used by 'if 0'ed code below. */
5106 register struct case_node **l;
5110 /* True iff the selector type is a numbered set mode. */
5113 /* The number of possible selector values. */
5116 /* For each possible selector value. a one iff it has been matched
5117 by a case value alternative. */
5118 unsigned char *cases_seen;
5120 /* The allocated size of cases_seen, in chars. */
5126 size = all_cases_count (type, &sparseness);
5127 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5129 if (size > 0 && size < 600000
5130 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5131 this optimization if we don't have enough memory rather than
5132 aborting, as xmalloc would do. */
5133 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5136 tree v = TYPE_VALUES (type);
5138 /* The time complexity of this code is normally O(N), where
5139 N being the number of members in the enumerated type.
5140 However, if type is a ENUMERAL_TYPE whose values do not
5141 increase monotonically, O(N*log(N)) time may be needed. */
5143 mark_seen_cases (type, cases_seen, size, sparseness);
5145 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5147 if (BITARRAY_TEST(cases_seen, i) == 0)
5148 warning ("enumeration value `%s' not handled in switch",
5149 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5155 /* Now we go the other way around; we warn if there are case
5156 expressions that don't correspond to enumerators. This can
5157 occur since C and C++ don't enforce type-checking of
5158 assignments to enumeration variables. */
5160 if (case_stack->data.case_stmt.case_list
5161 && case_stack->data.case_stmt.case_list->left)
5162 case_stack->data.case_stmt.case_list
5163 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5165 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5167 for (chain = TYPE_VALUES (type);
5168 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5169 chain = TREE_CHAIN (chain))
5174 if (TYPE_NAME (type) == 0)
5175 warning ("case value `%ld' not in enumerated type",
5176 (long) TREE_INT_CST_LOW (n->low));
5178 warning ("case value `%ld' not in enumerated type `%s'",
5179 (long) TREE_INT_CST_LOW (n->low),
5180 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5183 : DECL_NAME (TYPE_NAME (type))));
5185 if (!tree_int_cst_equal (n->low, n->high))
5187 for (chain = TYPE_VALUES (type);
5188 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5189 chain = TREE_CHAIN (chain))
5194 if (TYPE_NAME (type) == 0)
5195 warning ("case value `%ld' not in enumerated type",
5196 (long) TREE_INT_CST_LOW (n->high));
5198 warning ("case value `%ld' not in enumerated type `%s'",
5199 (long) TREE_INT_CST_LOW (n->high),
5200 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5203 : DECL_NAME (TYPE_NAME (type))));
5209 /* ??? This optimization is disabled because it causes valid programs to
5210 fail. ANSI C does not guarantee that an expression with enum type
5211 will have a value that is the same as one of the enumeration literals. */
5213 /* If all values were found as case labels, make one of them the default
5214 label. Thus, this switch will never fall through. We arbitrarily pick
5215 the last one to make the default since this is likely the most
5216 efficient choice. */
5220 for (l = &case_stack->data.case_stmt.case_list;
5225 case_stack->data.case_stmt.default_label = (*l)->code_label;
5232 /* Terminate a case (Pascal) or switch (C) statement
5233 in which ORIG_INDEX is the expression to be tested.
5234 Generate the code to test it and jump to the right place. */
5237 expand_end_case (orig_index)
5240 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5241 rtx default_label = 0;
5242 register struct case_node *n;
5250 register struct nesting *thiscase = case_stack;
5251 tree index_expr, index_type;
5254 /* Don't crash due to previous errors. */
5255 if (thiscase == NULL)
5258 table_label = gen_label_rtx ();
5259 index_expr = thiscase->data.case_stmt.index_expr;
5260 index_type = TREE_TYPE (index_expr);
5261 unsignedp = TREE_UNSIGNED (index_type);
5263 do_pending_stack_adjust ();
5265 /* This might get an spurious warning in the presence of a syntax error;
5266 it could be fixed by moving the call to check_seenlabel after the
5267 check for error_mark_node, and copying the code of check_seenlabel that
5268 deals with case_stack->data.case_stmt.line_number_status /
5269 restore_line_number_status in front of the call to end_cleanup_deferral;
5270 However, this might miss some useful warnings in the presence of
5271 non-syntax errors. */
5274 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5275 if (index_type != error_mark_node)
5277 /* If switch expression was an enumerated type, check that all
5278 enumeration literals are covered by the cases.
5279 No sense trying this if there's a default case, however. */
5281 if (!thiscase->data.case_stmt.default_label
5282 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5283 && TREE_CODE (index_expr) != INTEGER_CST)
5284 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5286 /* If we don't have a default-label, create one here,
5287 after the body of the switch. */
5288 if (thiscase->data.case_stmt.default_label == 0)
5290 thiscase->data.case_stmt.default_label
5291 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5292 expand_label (thiscase->data.case_stmt.default_label);
5294 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5296 before_case = get_last_insn ();
5298 if (thiscase->data.case_stmt.case_list
5299 && thiscase->data.case_stmt.case_list->left)
5300 thiscase->data.case_stmt.case_list
5301 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5303 /* Simplify the case-list before we count it. */
5304 group_case_nodes (thiscase->data.case_stmt.case_list);
5306 /* Get upper and lower bounds of case values.
5307 Also convert all the case values to the index expr's data type. */
5310 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5312 /* Check low and high label values are integers. */
5313 if (TREE_CODE (n->low) != INTEGER_CST)
5315 if (TREE_CODE (n->high) != INTEGER_CST)
5318 n->low = convert (index_type, n->low);
5319 n->high = convert (index_type, n->high);
5321 /* Count the elements and track the largest and smallest
5322 of them (treating them as signed even if they are not). */
5330 if (INT_CST_LT (n->low, minval))
5332 if (INT_CST_LT (maxval, n->high))
5335 /* A range counts double, since it requires two compares. */
5336 if (! tree_int_cst_equal (n->low, n->high))
5340 orig_minval = minval;
5342 /* Compute span of values. */
5344 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5346 end_cleanup_deferral ();
5350 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5352 emit_jump (default_label);
5355 /* If range of values is much bigger than number of values,
5356 make a sequence of conditional branches instead of a dispatch.
5357 If the switch-index is a constant, do it this way
5358 because we can optimize it. */
5360 #ifndef CASE_VALUES_THRESHOLD
5362 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5364 /* If machine does not have a case insn that compares the
5365 bounds, this means extra overhead for dispatch tables
5366 which raises the threshold for using them. */
5367 #define CASE_VALUES_THRESHOLD 5
5368 #endif /* HAVE_casesi */
5369 #endif /* CASE_VALUES_THRESHOLD */
5371 else if (TREE_INT_CST_HIGH (range) != 0
5372 || count < (unsigned int) CASE_VALUES_THRESHOLD
5373 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5375 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5378 || TREE_CODE (index_expr) == INTEGER_CST
5379 /* These will reduce to a constant. */
5380 || (TREE_CODE (index_expr) == CALL_EXPR
5381 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5382 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5383 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5384 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5385 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5386 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5388 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5390 /* If the index is a short or char that we do not have
5391 an insn to handle comparisons directly, convert it to
5392 a full integer now, rather than letting each comparison
5393 generate the conversion. */
5395 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5396 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5397 == CODE_FOR_nothing))
5399 enum machine_mode wider_mode;
5400 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5401 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5402 if (cmp_optab->handlers[(int) wider_mode].insn_code
5403 != CODE_FOR_nothing)
5405 index = convert_to_mode (wider_mode, index, unsignedp);
5411 do_pending_stack_adjust ();
5413 index = protect_from_queue (index, 0);
5414 if (GET_CODE (index) == MEM)
5415 index = copy_to_reg (index);
5416 if (GET_CODE (index) == CONST_INT
5417 || TREE_CODE (index_expr) == INTEGER_CST)
5419 /* Make a tree node with the proper constant value
5420 if we don't already have one. */
5421 if (TREE_CODE (index_expr) != INTEGER_CST)
5424 = build_int_2 (INTVAL (index),
5425 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5426 index_expr = convert (index_type, index_expr);
5429 /* For constant index expressions we need only
5430 issue a unconditional branch to the appropriate
5431 target code. The job of removing any unreachable
5432 code is left to the optimisation phase if the
5433 "-O" option is specified. */
5434 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5435 if (! tree_int_cst_lt (index_expr, n->low)
5436 && ! tree_int_cst_lt (n->high, index_expr))
5440 emit_jump (label_rtx (n->code_label));
5442 emit_jump (default_label);
5446 /* If the index expression is not constant we generate
5447 a binary decision tree to select the appropriate
5448 target code. This is done as follows:
5450 The list of cases is rearranged into a binary tree,
5451 nearly optimal assuming equal probability for each case.
5453 The tree is transformed into RTL, eliminating
5454 redundant test conditions at the same time.
5456 If program flow could reach the end of the
5457 decision tree an unconditional jump to the
5458 default code is emitted. */
5461 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5462 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5463 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5465 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5466 default_label, index_type);
5467 emit_jump_if_reachable (default_label);
5476 enum machine_mode index_mode = SImode;
5477 int index_bits = GET_MODE_BITSIZE (index_mode);
5479 enum machine_mode op_mode;
5481 /* Convert the index to SImode. */
5482 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5483 > GET_MODE_BITSIZE (index_mode))
5485 enum machine_mode omode = TYPE_MODE (index_type);
5486 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5488 /* We must handle the endpoints in the original mode. */
5489 index_expr = build (MINUS_EXPR, index_type,
5490 index_expr, minval);
5491 minval = integer_zero_node;
5492 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5493 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5494 omode, 1, 0, default_label);
5495 /* Now we can safely truncate. */
5496 index = convert_to_mode (index_mode, index, 0);
5500 if (TYPE_MODE (index_type) != index_mode)
5502 index_expr = convert (type_for_size (index_bits, 0),
5504 index_type = TREE_TYPE (index_expr);
5507 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5510 index = protect_from_queue (index, 0);
5511 do_pending_stack_adjust ();
5513 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5514 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5516 index = copy_to_mode_reg (op_mode, index);
5518 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5520 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5521 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5523 op1 = copy_to_mode_reg (op_mode, op1);
5525 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5527 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5528 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5530 op2 = copy_to_mode_reg (op_mode, op2);
5532 emit_jump_insn (gen_casesi (index, op1, op2,
5533 table_label, default_label));
5537 #ifdef HAVE_tablejump
5538 if (! win && HAVE_tablejump)
5540 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5541 fold (build (MINUS_EXPR, index_type,
5542 index_expr, minval)));
5543 index_type = TREE_TYPE (index_expr);
5544 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5546 index = protect_from_queue (index, 0);
5547 do_pending_stack_adjust ();
5549 do_tablejump (index, TYPE_MODE (index_type),
5550 expand_expr (range, NULL_RTX, VOIDmode, 0),
5551 table_label, default_label);
5558 /* Get table of labels to jump to, in order of case index. */
5560 ncases = TREE_INT_CST_LOW (range) + 1;
5561 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5562 bzero ((char *) labelvec, ncases * sizeof (rtx));
5564 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5566 register HOST_WIDE_INT i
5567 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5572 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5573 if (i + TREE_INT_CST_LOW (orig_minval)
5574 == TREE_INT_CST_LOW (n->high))
5580 /* Fill in the gaps with the default. */
5581 for (i = 0; i < ncases; i++)
5582 if (labelvec[i] == 0)
5583 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5585 /* Output the table */
5586 emit_label (table_label);
5588 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5589 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5590 gen_rtx_LABEL_REF (Pmode, table_label),
5591 gen_rtvec_v (ncases, labelvec),
5592 const0_rtx, const0_rtx));
5594 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5595 gen_rtvec_v (ncases, labelvec)));
5597 /* If the case insn drops through the table,
5598 after the table we must jump to the default-label.
5599 Otherwise record no drop-through after the table. */
5600 #ifdef CASE_DROPS_THROUGH
5601 emit_jump (default_label);
5607 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5608 reorder_insns (before_case, get_last_insn (),
5609 thiscase->data.case_stmt.start);
5612 end_cleanup_deferral ();
5614 if (thiscase->exit_label)
5615 emit_label (thiscase->exit_label);
5617 POPSTACK (case_stack);
5622 /* Convert the tree NODE into a list linked by the right field, with the left
5623 field zeroed. RIGHT is used for recursion; it is a list to be placed
5624 rightmost in the resulting list. */
5626 static struct case_node *
5627 case_tree2list (node, right)
5628 struct case_node *node, *right;
5630 struct case_node *left;
5633 right = case_tree2list (node->right, right);
5635 node->right = right;
5636 if ((left = node->left))
5639 return case_tree2list (left, node);
5645 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5648 do_jump_if_equal (op1, op2, label, unsignedp)
5649 rtx op1, op2, label;
5652 if (GET_CODE (op1) == CONST_INT
5653 && GET_CODE (op2) == CONST_INT)
5655 if (INTVAL (op1) == INTVAL (op2))
5660 enum machine_mode mode = GET_MODE (op1);
5661 if (mode == VOIDmode)
5662 mode = GET_MODE (op2);
5663 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5668 /* Not all case values are encountered equally. This function
5669 uses a heuristic to weight case labels, in cases where that
5670 looks like a reasonable thing to do.
5672 Right now, all we try to guess is text, and we establish the
5675 chars above space: 16
5684 If we find any cases in the switch that are not either -1 or in the range
5685 of valid ASCII characters, or are control characters other than those
5686 commonly used with "\", don't treat this switch scanning text.
5688 Return 1 if these nodes are suitable for cost estimation, otherwise
5692 estimate_case_costs (node)
5695 tree min_ascii = build_int_2 (-1, -1);
5696 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5700 /* If we haven't already made the cost table, make it now. Note that the
5701 lower bound of the table is -1, not zero. */
5703 if (cost_table == NULL)
5705 cost_table = cost_table_ + 1;
5707 for (i = 0; i < 128; i++)
5711 else if (ISPUNCT (i))
5713 else if (ISCNTRL (i))
5717 cost_table[' '] = 8;
5718 cost_table['\t'] = 4;
5719 cost_table['\0'] = 4;
5720 cost_table['\n'] = 2;
5721 cost_table['\f'] = 1;
5722 cost_table['\v'] = 1;
5723 cost_table['\b'] = 1;
5726 /* See if all the case expressions look like text. It is text if the
5727 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5728 as signed arithmetic since we don't want to ever access cost_table with a
5729 value less than -1. Also check that none of the constants in a range
5730 are strange control characters. */
5732 for (n = node; n; n = n->right)
5734 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5737 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5738 if (cost_table[i] < 0)
5742 /* All interesting values are within the range of interesting
5743 ASCII characters. */
5747 /* Scan an ordered list of case nodes
5748 combining those with consecutive values or ranges.
5750 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5753 group_case_nodes (head)
5756 case_node_ptr node = head;
5760 rtx lb = next_real_insn (label_rtx (node->code_label));
5762 case_node_ptr np = node;
5764 /* Try to group the successors of NODE with NODE. */
5765 while (((np = np->right) != 0)
5766 /* Do they jump to the same place? */
5767 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5768 || (lb != 0 && lb2 != 0
5769 && simplejump_p (lb)
5770 && simplejump_p (lb2)
5771 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5772 SET_SRC (PATTERN (lb2)))))
5773 /* Are their ranges consecutive? */
5774 && tree_int_cst_equal (np->low,
5775 fold (build (PLUS_EXPR,
5776 TREE_TYPE (node->high),
5779 /* An overflow is not consecutive. */
5780 && tree_int_cst_lt (node->high,
5781 fold (build (PLUS_EXPR,
5782 TREE_TYPE (node->high),
5784 integer_one_node))))
5786 node->high = np->high;
5788 /* NP is the first node after NODE which can't be grouped with it.
5789 Delete the nodes in between, and move on to that node. */
5795 /* Take an ordered list of case nodes
5796 and transform them into a near optimal binary tree,
5797 on the assumption that any target code selection value is as
5798 likely as any other.
5800 The transformation is performed by splitting the ordered
5801 list into two equal sections plus a pivot. The parts are
5802 then attached to the pivot as left and right branches. Each
5803 branch is then transformed recursively. */
5806 balance_case_nodes (head, parent)
5807 case_node_ptr *head;
5808 case_node_ptr parent;
5810 register case_node_ptr np;
5818 register case_node_ptr *npp;
5821 /* Count the number of entries on branch. Also count the ranges. */
5825 if (!tree_int_cst_equal (np->low, np->high))
5829 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5833 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5841 /* Split this list if it is long enough for that to help. */
5846 /* Find the place in the list that bisects the list's total cost,
5847 Here I gets half the total cost. */
5852 /* Skip nodes while their cost does not reach that amount. */
5853 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5854 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5855 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5858 npp = &(*npp)->right;
5863 /* Leave this branch lopsided, but optimize left-hand
5864 side and fill in `parent' fields for right-hand side. */
5866 np->parent = parent;
5867 balance_case_nodes (&np->left, np);
5868 for (; np->right; np = np->right)
5869 np->right->parent = np;
5873 /* If there are just three nodes, split at the middle one. */
5875 npp = &(*npp)->right;
5878 /* Find the place in the list that bisects the list's total cost,
5879 where ranges count as 2.
5880 Here I gets half the total cost. */
5881 i = (i + ranges + 1) / 2;
5884 /* Skip nodes while their cost does not reach that amount. */
5885 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5890 npp = &(*npp)->right;
5895 np->parent = parent;
5898 /* Optimize each of the two split parts. */
5899 balance_case_nodes (&np->left, np);
5900 balance_case_nodes (&np->right, np);
5904 /* Else leave this branch as one level,
5905 but fill in `parent' fields. */
5907 np->parent = parent;
5908 for (; np->right; np = np->right)
5909 np->right->parent = np;
5914 /* Search the parent sections of the case node tree
5915 to see if a test for the lower bound of NODE would be redundant.
5916 INDEX_TYPE is the type of the index expression.
5918 The instructions to generate the case decision tree are
5919 output in the same order as nodes are processed so it is
5920 known that if a parent node checks the range of the current
5921 node minus one that the current node is bounded at its lower
5922 span. Thus the test would be redundant. */
5925 node_has_low_bound (node, index_type)
5930 case_node_ptr pnode;
5932 /* If the lower bound of this node is the lowest value in the index type,
5933 we need not test it. */
5935 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5938 /* If this node has a left branch, the value at the left must be less
5939 than that at this node, so it cannot be bounded at the bottom and
5940 we need not bother testing any further. */
5945 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5946 node->low, integer_one_node));
5948 /* If the subtraction above overflowed, we can't verify anything.
5949 Otherwise, look for a parent that tests our value - 1. */
5951 if (! tree_int_cst_lt (low_minus_one, node->low))
5954 for (pnode = node->parent; pnode; pnode = pnode->parent)
5955 if (tree_int_cst_equal (low_minus_one, pnode->high))
5961 /* Search the parent sections of the case node tree
5962 to see if a test for the upper bound of NODE would be redundant.
5963 INDEX_TYPE is the type of the index expression.
5965 The instructions to generate the case decision tree are
5966 output in the same order as nodes are processed so it is
5967 known that if a parent node checks the range of the current
5968 node plus one that the current node is bounded at its upper
5969 span. Thus the test would be redundant. */
5972 node_has_high_bound (node, index_type)
5977 case_node_ptr pnode;
5979 /* If there is no upper bound, obviously no test is needed. */
5981 if (TYPE_MAX_VALUE (index_type) == NULL)
5984 /* If the upper bound of this node is the highest value in the type
5985 of the index expression, we need not test against it. */
5987 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5990 /* If this node has a right branch, the value at the right must be greater
5991 than that at this node, so it cannot be bounded at the top and
5992 we need not bother testing any further. */
5997 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5998 node->high, integer_one_node));
6000 /* If the addition above overflowed, we can't verify anything.
6001 Otherwise, look for a parent that tests our value + 1. */
6003 if (! tree_int_cst_lt (node->high, high_plus_one))
6006 for (pnode = node->parent; pnode; pnode = pnode->parent)
6007 if (tree_int_cst_equal (high_plus_one, pnode->low))
6013 /* Search the parent sections of the
6014 case node tree to see if both tests for the upper and lower
6015 bounds of NODE would be redundant. */
6018 node_is_bounded (node, index_type)
6022 return (node_has_low_bound (node, index_type)
6023 && node_has_high_bound (node, index_type));
6026 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6029 emit_jump_if_reachable (label)
6032 if (GET_CODE (get_last_insn ()) != BARRIER)
6036 /* Emit step-by-step code to select a case for the value of INDEX.
6037 The thus generated decision tree follows the form of the
6038 case-node binary tree NODE, whose nodes represent test conditions.
6039 INDEX_TYPE is the type of the index of the switch.
6041 Care is taken to prune redundant tests from the decision tree
6042 by detecting any boundary conditions already checked by
6043 emitted rtx. (See node_has_high_bound, node_has_low_bound
6044 and node_is_bounded, above.)
6046 Where the test conditions can be shown to be redundant we emit
6047 an unconditional jump to the target code. As a further
6048 optimization, the subordinates of a tree node are examined to
6049 check for bounded nodes. In this case conditional and/or
6050 unconditional jumps as a result of the boundary check for the
6051 current node are arranged to target the subordinates associated
6052 code for out of bound conditions on the current node.
6054 We can assume that when control reaches the code generated here,
6055 the index value has already been compared with the parents
6056 of this node, and determined to be on the same side of each parent
6057 as this node is. Thus, if this node tests for the value 51,
6058 and a parent tested for 52, we don't need to consider
6059 the possibility of a value greater than 51. If another parent
6060 tests for the value 50, then this node need not test anything. */
6063 emit_case_nodes (index, node, default_label, index_type)
6069 /* If INDEX has an unsigned type, we must make unsigned branches. */
6070 int unsignedp = TREE_UNSIGNED (index_type);
6071 enum machine_mode mode = GET_MODE (index);
6073 /* See if our parents have already tested everything for us.
6074 If they have, emit an unconditional jump for this node. */
6075 if (node_is_bounded (node, index_type))
6076 emit_jump (label_rtx (node->code_label));
6078 else if (tree_int_cst_equal (node->low, node->high))
6080 /* Node is single valued. First see if the index expression matches
6081 this node and then check our children, if any. */
6083 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6084 label_rtx (node->code_label), unsignedp);
6086 if (node->right != 0 && node->left != 0)
6088 /* This node has children on both sides.
6089 Dispatch to one side or the other
6090 by comparing the index value with this node's value.
6091 If one subtree is bounded, check that one first,
6092 so we can avoid real branches in the tree. */
6094 if (node_is_bounded (node->right, index_type))
6096 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6098 GT, NULL_RTX, mode, unsignedp, 0,
6099 label_rtx (node->right->code_label));
6100 emit_case_nodes (index, node->left, default_label, index_type);
6103 else if (node_is_bounded (node->left, index_type))
6105 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6107 LT, NULL_RTX, mode, unsignedp, 0,
6108 label_rtx (node->left->code_label));
6109 emit_case_nodes (index, node->right, default_label, index_type);
6114 /* Neither node is bounded. First distinguish the two sides;
6115 then emit the code for one side at a time. */
6118 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6120 /* See if the value is on the right. */
6121 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6123 GT, NULL_RTX, mode, unsignedp, 0,
6124 label_rtx (test_label));
6126 /* Value must be on the left.
6127 Handle the left-hand subtree. */
6128 emit_case_nodes (index, node->left, default_label, index_type);
6129 /* If left-hand subtree does nothing,
6131 emit_jump_if_reachable (default_label);
6133 /* Code branches here for the right-hand subtree. */
6134 expand_label (test_label);
6135 emit_case_nodes (index, node->right, default_label, index_type);
6139 else if (node->right != 0 && node->left == 0)
6141 /* Here we have a right child but no left so we issue conditional
6142 branch to default and process the right child.
6144 Omit the conditional branch to default if we it avoid only one
6145 right child; it costs too much space to save so little time. */
6147 if (node->right->right || node->right->left
6148 || !tree_int_cst_equal (node->right->low, node->right->high))
6150 if (!node_has_low_bound (node, index_type))
6152 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6155 LT, NULL_RTX, mode, unsignedp, 0,
6159 emit_case_nodes (index, node->right, default_label, index_type);
6162 /* We cannot process node->right normally
6163 since we haven't ruled out the numbers less than
6164 this node's value. So handle node->right explicitly. */
6165 do_jump_if_equal (index,
6166 expand_expr (node->right->low, NULL_RTX,
6168 label_rtx (node->right->code_label), unsignedp);
6171 else if (node->right == 0 && node->left != 0)
6173 /* Just one subtree, on the left. */
6175 #if 0 /* The following code and comment were formerly part
6176 of the condition here, but they didn't work
6177 and I don't understand what the idea was. -- rms. */
6178 /* If our "most probable entry" is less probable
6179 than the default label, emit a jump to
6180 the default label using condition codes
6181 already lying around. With no right branch,
6182 a branch-greater-than will get us to the default
6185 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6188 if (node->left->left || node->left->right
6189 || !tree_int_cst_equal (node->left->low, node->left->high))
6191 if (!node_has_high_bound (node, index_type))
6193 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6196 GT, NULL_RTX, mode, unsignedp, 0,
6200 emit_case_nodes (index, node->left, default_label, index_type);
6203 /* We cannot process node->left normally
6204 since we haven't ruled out the numbers less than
6205 this node's value. So handle node->left explicitly. */
6206 do_jump_if_equal (index,
6207 expand_expr (node->left->low, NULL_RTX,
6209 label_rtx (node->left->code_label), unsignedp);
6214 /* Node is a range. These cases are very similar to those for a single
6215 value, except that we do not start by testing whether this node
6216 is the one to branch to. */
6218 if (node->right != 0 && node->left != 0)
6220 /* Node has subtrees on both sides.
6221 If the right-hand subtree is bounded,
6222 test for it first, since we can go straight there.
6223 Otherwise, we need to make a branch in the control structure,
6224 then handle the two subtrees. */
6225 tree test_label = 0;
6228 if (node_is_bounded (node->right, index_type))
6229 /* Right hand node is fully bounded so we can eliminate any
6230 testing and branch directly to the target code. */
6231 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6233 GT, NULL_RTX, mode, unsignedp, 0,
6234 label_rtx (node->right->code_label));
6237 /* Right hand node requires testing.
6238 Branch to a label where we will handle it later. */
6240 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6241 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6243 GT, NULL_RTX, mode, unsignedp, 0,
6244 label_rtx (test_label));
6247 /* Value belongs to this node or to the left-hand subtree. */
6249 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6251 GE, NULL_RTX, mode, unsignedp, 0,
6252 label_rtx (node->code_label));
6254 /* Handle the left-hand subtree. */
6255 emit_case_nodes (index, node->left, default_label, index_type);
6257 /* If right node had to be handled later, do that now. */
6261 /* If the left-hand subtree fell through,
6262 don't let it fall into the right-hand subtree. */
6263 emit_jump_if_reachable (default_label);
6265 expand_label (test_label);
6266 emit_case_nodes (index, node->right, default_label, index_type);
6270 else if (node->right != 0 && node->left == 0)
6272 /* Deal with values to the left of this node,
6273 if they are possible. */
6274 if (!node_has_low_bound (node, index_type))
6276 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6278 LT, NULL_RTX, mode, unsignedp, 0,
6282 /* Value belongs to this node or to the right-hand subtree. */
6284 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6286 LE, NULL_RTX, mode, unsignedp, 0,
6287 label_rtx (node->code_label));
6289 emit_case_nodes (index, node->right, default_label, index_type);
6292 else if (node->right == 0 && node->left != 0)
6294 /* Deal with values to the right of this node,
6295 if they are possible. */
6296 if (!node_has_high_bound (node, index_type))
6298 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6300 GT, NULL_RTX, mode, unsignedp, 0,
6304 /* Value belongs to this node or to the left-hand subtree. */
6306 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6308 GE, NULL_RTX, mode, unsignedp, 0,
6309 label_rtx (node->code_label));
6311 emit_case_nodes (index, node->left, default_label, index_type);
6316 /* Node has no children so we check low and high bounds to remove
6317 redundant tests. Only one of the bounds can exist,
6318 since otherwise this node is bounded--a case tested already. */
6320 if (!node_has_high_bound (node, index_type))
6322 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6324 GT, NULL_RTX, mode, unsignedp, 0,
6328 if (!node_has_low_bound (node, index_type))
6330 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6332 LT, NULL_RTX, mode, unsignedp, 0,
6336 emit_jump (label_rtx (node->code_label));
6341 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6342 so that the debugging info will be correct for the unrolled loop. */
6345 find_loop_tree_blocks ()
6347 identify_blocks (DECL_INITIAL (current_function_decl), get_insns ());
6351 unroll_block_trees ()
6353 tree block = DECL_INITIAL (current_function_decl);
6355 reorder_blocks (block, get_insns ());