1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 /* This file handles the generation of rtl code from tree structure
24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
25 It also creates the rtl expressions for parameters and auto variables
26 and has full responsibility for allocating stack slots.
28 The functions whose names start with `expand_' are called by the
29 parser to generate RTL instructions for various kinds of constructs.
31 Some control and binding constructs require calling several such
32 functions at different times. For example, a simple if-then
33 is expanded by calling `expand_start_cond' (with the condition-expression
34 as argument) before parsing the then-clause and calling `expand_end_cond'
35 after parsing the then-clause. */
46 #include "insn-flags.h"
47 #include "insn-config.h"
48 #include "insn-codes.h"
50 #include "hard-reg-set.h"
59 #define obstack_chunk_alloc xmalloc
60 #define obstack_chunk_free free
61 struct obstack stmt_obstack;
63 /* Assume that case vectors are not pc-relative. */
64 #ifndef CASE_VECTOR_PC_RELATIVE
65 #define CASE_VECTOR_PC_RELATIVE 0
69 /* Functions and data structures for expanding case statements. */
71 /* Case label structure, used to hold info on labels within case
72 statements. We handle "range" labels; for a single-value label
73 as in C, the high and low limits are the same.
75 An AVL tree of case nodes is initially created, and later transformed
76 to a list linked via the RIGHT fields in the nodes. Nodes with
77 higher case values are later in the list.
79 Switch statements can be output in one of two forms. A branch table
80 is used if there are more than a few labels and the labels are dense
81 within the range between the smallest and largest case value. If a
82 branch table is used, no further manipulations are done with the case
85 The alternative to the use of a branch table is to generate a series
86 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
87 and PARENT fields to hold a binary tree. Initially the tree is
88 totally unbalanced, with everything on the right. We balance the tree
89 with nodes on the left having lower case values than the parent
90 and nodes on the right having higher values. We then output the tree
95 struct case_node *left; /* Left son in binary tree */
96 struct case_node *right; /* Right son in binary tree; also node chain */
97 struct case_node *parent; /* Parent of node in binary tree */
98 tree low; /* Lowest index value for this label */
99 tree high; /* Highest index value for this label */
100 tree code_label; /* Label to jump to when node matches */
104 typedef struct case_node case_node;
105 typedef struct case_node *case_node_ptr;
107 /* These are used by estimate_case_costs and balance_case_nodes. */
109 /* This must be a signed type, and non-ANSI compilers lack signed char. */
110 static short cost_table_[129];
111 static short *cost_table;
112 static int use_cost_table;
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
142 struct nesting *next;
147 /* For conds (if-then and if-then-else statements). */
150 /* Label for the end of the if construct.
151 There is none if EXITFLAG was not set
152 and no `else' has been seen yet. */
154 /* Label for the end of this alternative.
155 This may be the end of the if or the next else/elseif. */
161 /* Label at the top of the loop; place to loop back to. */
163 /* Label at the end of the whole construct. */
165 /* Label before a jump that branches to the end of the whole
166 construct. This is where destructors go if any. */
168 /* Label for `continue' statement to jump to;
169 this is in front of the stepper of the loop. */
172 /* For variable binding contours. */
175 /* Sequence number of this binding contour within the function,
176 in order of entry. */
177 int block_start_count;
178 /* Nonzero => value to restore stack to on exit. */
180 /* The NOTE that starts this contour.
181 Used by expand_goto to check whether the destination
182 is within each contour or not. */
184 /* Innermost containing binding contour that has a stack level. */
185 struct nesting *innermost_stack_block;
186 /* List of cleanups to be run on exit from this contour.
187 This is a list of expressions to be evaluated.
188 The TREE_PURPOSE of each link is the ..._DECL node
189 which the cleanup pertains to. */
191 /* List of cleanup-lists of blocks containing this block,
192 as they were at the locus where this block appears.
193 There is an element for each containing block,
194 ordered innermost containing block first.
195 The tail of this list can be 0,
196 if all remaining elements would be empty lists.
197 The element's TREE_VALUE is the cleanup-list of that block,
198 which may be null. */
200 /* Chain of labels defined inside this binding contour.
201 For contours that have stack levels or cleanups. */
202 struct label_chain *label_chain;
203 /* Number of function calls seen, as of start of this block. */
204 int n_function_calls;
205 /* Nonzero if this is associated with a EH region. */
206 int exception_region;
207 /* The saved target_temp_slot_level from our outer block.
208 We may reset target_temp_slot_level to be the level of
209 this block, if that is done, target_temp_slot_level
210 reverts to the saved target_temp_slot_level at the very
212 int block_target_temp_slot_level;
213 /* True if we are currently emitting insns in an area of
214 output code that is controlled by a conditional
215 expression. This is used by the cleanup handling code to
216 generate conditional cleanup actions. */
217 int conditional_code;
218 /* A place to move the start of the exception region for any
219 of the conditional cleanups, must be at the end or after
220 the start of the last unconditional cleanup, and before any
221 conditional branch points. */
222 rtx last_unconditional_cleanup;
223 /* When in a conditional context, this is the specific
224 cleanup list associated with last_unconditional_cleanup,
225 where we place the conditionalized cleanups. */
228 /* For switch (C) or case (Pascal) statements,
229 and also for dummies (see `expand_start_case_dummy'). */
232 /* The insn after which the case dispatch should finally
233 be emitted. Zero for a dummy. */
235 /* A list of case labels; it is first built as an AVL tree.
236 During expand_end_case, this is converted to a list, and may be
237 rearranged into a nearly balanced binary tree. */
238 struct case_node *case_list;
239 /* Label to jump to if no case matches. */
241 /* The expression to be dispatched on. */
243 /* Type that INDEX_EXPR should be converted to. */
245 /* Number of range exprs in case statement. */
247 /* Name of this kind of statement, for warnings. */
248 const char *printname;
249 /* Used to save no_line_numbers till we see the first case label.
250 We set this to -1 when we see the first case label in this
252 int line_number_status;
257 /* Allocate and return a new `struct nesting'. */
259 #define ALLOC_NESTING() \
260 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
262 /* Pop the nesting stack element by element until we pop off
263 the element which is at the top of STACK.
264 Update all the other stacks, popping off elements from them
265 as we pop them from nesting_stack. */
267 #define POPSTACK(STACK) \
268 do { struct nesting *target = STACK; \
269 struct nesting *this; \
270 do { this = nesting_stack; \
271 if (loop_stack == this) \
272 loop_stack = loop_stack->next; \
273 if (cond_stack == this) \
274 cond_stack = cond_stack->next; \
275 if (block_stack == this) \
276 block_stack = block_stack->next; \
277 if (stack_block_stack == this) \
278 stack_block_stack = stack_block_stack->next; \
279 if (case_stack == this) \
280 case_stack = case_stack->next; \
281 nesting_depth = nesting_stack->depth - 1; \
282 nesting_stack = this->all; \
283 obstack_free (&stmt_obstack, this); } \
284 while (this != target); } while (0)
286 /* In some cases it is impossible to generate code for a forward goto
287 until the label definition is seen. This happens when it may be necessary
288 for the goto to reset the stack pointer: we don't yet know how to do that.
289 So expand_goto puts an entry on this fixup list.
290 Each time a binding contour that resets the stack is exited,
292 If the target label has now been defined, we can insert the proper code. */
296 /* Points to following fixup. */
297 struct goto_fixup *next;
298 /* Points to the insn before the jump insn.
299 If more code must be inserted, it goes after this insn. */
301 /* The LABEL_DECL that this jump is jumping to, or 0
302 for break, continue or return. */
304 /* The BLOCK for the place where this goto was found. */
306 /* The CODE_LABEL rtx that this is jumping to. */
308 /* Number of binding contours started in current function
309 before the label reference. */
310 int block_start_count;
311 /* The outermost stack level that should be restored for this jump.
312 Each time a binding contour that resets the stack is exited,
313 if the target label is *not* yet defined, this slot is updated. */
315 /* List of lists of cleanup expressions to be run by this goto.
316 There is one element for each block that this goto is within.
317 The tail of this list can be 0,
318 if all remaining elements would be empty.
319 The TREE_VALUE contains the cleanup list of that block as of the
320 time this goto was seen.
321 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
322 tree cleanup_list_list;
325 /* Within any binding contour that must restore a stack level,
326 all labels are recorded with a chain of these structures. */
330 /* Points to following fixup. */
331 struct label_chain *next;
337 /* Chain of all pending binding contours. */
338 struct nesting *x_block_stack;
340 /* If any new stacks are added here, add them to POPSTACKS too. */
342 /* Chain of all pending binding contours that restore stack levels
344 struct nesting *x_stack_block_stack;
346 /* Chain of all pending conditional statements. */
347 struct nesting *x_cond_stack;
349 /* Chain of all pending loops. */
350 struct nesting *x_loop_stack;
352 /* Chain of all pending case or switch statements. */
353 struct nesting *x_case_stack;
355 /* Separate chain including all of the above,
356 chained through the `all' field. */
357 struct nesting *x_nesting_stack;
359 /* Number of entries on nesting_stack now. */
362 /* Number of binding contours started so far in this function. */
363 int x_block_start_count;
365 /* Each time we expand an expression-statement,
366 record the expr's type and its RTL value here. */
367 tree x_last_expr_type;
368 rtx x_last_expr_value;
370 /* Nonzero if within a ({...}) grouping, in which case we must
371 always compute a value for each expr-stmt in case it is the last one. */
372 int x_expr_stmts_for_value;
374 /* Filename and line number of last line-number note,
375 whether we actually emitted it or not. */
376 const char *x_emit_filename;
379 struct goto_fixup *x_goto_fixup_chain;
382 #define block_stack (cfun->stmt->x_block_stack)
383 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
384 #define cond_stack (cfun->stmt->x_cond_stack)
385 #define loop_stack (cfun->stmt->x_loop_stack)
386 #define case_stack (cfun->stmt->x_case_stack)
387 #define nesting_stack (cfun->stmt->x_nesting_stack)
388 #define nesting_depth (cfun->stmt->x_nesting_depth)
389 #define current_block_start_count (cfun->stmt->x_block_start_count)
390 #define last_expr_type (cfun->stmt->x_last_expr_type)
391 #define last_expr_value (cfun->stmt->x_last_expr_value)
392 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
393 #define emit_filename (cfun->stmt->x_emit_filename)
394 #define emit_lineno (cfun->stmt->x_emit_lineno)
395 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
397 /* Non-zero if we are using EH to handle cleanus. */
398 static int using_eh_for_cleanups_p = 0;
400 /* Character strings, each containing a single decimal digit. */
401 static char *digit_strings[10];
404 static int n_occurrences PARAMS ((int, const char *));
405 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
406 static int expand_fixup PARAMS ((tree, rtx, rtx));
407 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
408 static void expand_nl_goto_receiver PARAMS ((void));
409 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
410 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
412 static void expand_null_return_1 PARAMS ((rtx, int));
413 static void expand_value_return PARAMS ((rtx));
414 static int tail_recursion_args PARAMS ((tree, tree));
415 static void expand_cleanups PARAMS ((tree, tree, int, int));
416 static void check_seenlabel PARAMS ((void));
417 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
418 static int estimate_case_costs PARAMS ((case_node_ptr));
419 static void group_case_nodes PARAMS ((case_node_ptr));
420 static void balance_case_nodes PARAMS ((case_node_ptr *,
422 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
423 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
424 static int node_is_bounded PARAMS ((case_node_ptr, tree));
425 static void emit_jump_if_reachable PARAMS ((rtx));
426 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
427 static int add_case_node PARAMS ((tree, tree, tree, tree *));
428 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
429 static void mark_cond_nesting PARAMS ((struct nesting *));
430 static void mark_loop_nesting PARAMS ((struct nesting *));
431 static void mark_block_nesting PARAMS ((struct nesting *));
432 static void mark_case_nesting PARAMS ((struct nesting *));
433 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
437 using_eh_for_cleanups ()
439 using_eh_for_cleanups_p = 1;
442 /* Mark N (known to be a cond-nesting) for GC. */
445 mark_cond_nesting (n)
450 ggc_mark_rtx (n->exit_label);
451 ggc_mark_rtx (n->data.cond.endif_label);
452 ggc_mark_rtx (n->data.cond.next_label);
458 /* Mark N (known to be a loop-nesting) for GC. */
461 mark_loop_nesting (n)
467 ggc_mark_rtx (n->exit_label);
468 ggc_mark_rtx (n->data.loop.start_label);
469 ggc_mark_rtx (n->data.loop.end_label);
470 ggc_mark_rtx (n->data.loop.alt_end_label);
471 ggc_mark_rtx (n->data.loop.continue_label);
477 /* Mark N (known to be a block-nesting) for GC. */
480 mark_block_nesting (n)
485 struct label_chain *l;
487 ggc_mark_rtx (n->exit_label);
488 ggc_mark_rtx (n->data.block.stack_level);
489 ggc_mark_rtx (n->data.block.first_insn);
490 ggc_mark_tree (n->data.block.cleanups);
491 ggc_mark_tree (n->data.block.outer_cleanups);
493 for (l = n->data.block.label_chain; l != NULL; l = l->next)
494 ggc_mark_tree (l->label);
496 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
498 /* ??? cleanup_ptr never points outside the stack, does it? */
504 /* Mark N (known to be a case-nesting) for GC. */
507 mark_case_nesting (n)
512 struct case_node *node;
514 ggc_mark_rtx (n->exit_label);
515 ggc_mark_rtx (n->data.case_stmt.start);
517 node = n->data.case_stmt.case_list;
520 ggc_mark_tree (node->low);
521 ggc_mark_tree (node->high);
522 ggc_mark_tree (node->code_label);
526 ggc_mark_tree (n->data.case_stmt.default_label);
527 ggc_mark_tree (n->data.case_stmt.index_expr);
528 ggc_mark_tree (n->data.case_stmt.nominal_type);
538 struct goto_fixup *g;
543 ggc_mark_rtx (g->before_jump);
544 ggc_mark_tree (g->target);
545 ggc_mark_tree (g->context);
546 ggc_mark_rtx (g->target_rtl);
547 ggc_mark_rtx (g->stack_level);
548 ggc_mark_tree (g->cleanup_list_list);
554 /* Clear out all parts of the state in F that can safely be discarded
555 after the function has been compiled, to let garbage collection
556 reclaim the memory. */
562 /* We're about to free the function obstack. If we hold pointers to
563 things allocated there, then we'll try to mark them when we do
564 GC. So, we clear them out here explicitly. */
574 struct stmt_status *p;
579 mark_block_nesting (p->x_block_stack);
580 mark_cond_nesting (p->x_cond_stack);
581 mark_loop_nesting (p->x_loop_stack);
582 mark_case_nesting (p->x_case_stack);
584 ggc_mark_tree (p->x_last_expr_type);
585 /* last_epxr_value is only valid if last_expr_type is nonzero. */
586 if (p->x_last_expr_type)
587 ggc_mark_rtx (p->x_last_expr_value);
589 mark_goto_fixup (p->x_goto_fixup_chain);
597 gcc_obstack_init (&stmt_obstack);
599 for (i = 0; i < 10; i++)
601 digit_strings[i] = ggc_alloc_string (NULL, 1);
602 digit_strings[i][0] = '0' + i;
604 ggc_add_string_root (digit_strings, 10);
608 init_stmt_for_function ()
610 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
612 /* We are not currently within any block, conditional, loop or case. */
614 stack_block_stack = 0;
621 current_block_start_count = 0;
623 /* No gotos have been expanded yet. */
624 goto_fixup_chain = 0;
626 /* We are not processing a ({...}) grouping. */
627 expr_stmts_for_value = 0;
629 last_expr_value = NULL_RTX;
632 /* Return nonzero if anything is pushed on the loop, condition, or case
637 return cond_stack || loop_stack || case_stack;
640 /* Record the current file and line. Called from emit_line_note. */
642 set_file_and_line_for_stmt (file, line)
646 /* If we're outputting an inline function, and we add a line note,
647 there may be no CFUN->STMT information. So, there's no need to
651 emit_filename = file;
656 /* Emit a no-op instruction. */
663 last_insn = get_last_insn ();
665 && (GET_CODE (last_insn) == CODE_LABEL
666 || (GET_CODE (last_insn) == NOTE
667 && prev_real_insn (last_insn) == 0)))
668 emit_insn (gen_nop ());
671 /* Return the rtx-label that corresponds to a LABEL_DECL,
672 creating it if necessary. */
678 if (TREE_CODE (label) != LABEL_DECL)
681 if (DECL_RTL (label))
682 return DECL_RTL (label);
684 return DECL_RTL (label) = gen_label_rtx ();
687 /* Add an unconditional jump to LABEL as the next sequential instruction. */
693 do_pending_stack_adjust ();
694 emit_jump_insn (gen_jump (label));
698 /* Emit code to jump to the address
699 specified by the pointer expression EXP. */
702 expand_computed_goto (exp)
705 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
707 #ifdef POINTERS_EXTEND_UNSIGNED
708 x = convert_memory_address (Pmode, x);
712 /* Be sure the function is executable. */
713 if (current_function_check_memory_usage)
714 emit_library_call (chkr_check_exec_libfunc, 1,
715 VOIDmode, 1, x, ptr_mode);
717 do_pending_stack_adjust ();
718 emit_indirect_jump (x);
720 current_function_has_computed_jump = 1;
723 /* Handle goto statements and the labels that they can go to. */
725 /* Specify the location in the RTL code of a label LABEL,
726 which is a LABEL_DECL tree node.
728 This is used for the kind of label that the user can jump to with a
729 goto statement, and for alternatives of a switch or case statement.
730 RTL labels generated for loops and conditionals don't go through here;
731 they are generated directly at the RTL level, by other functions below.
733 Note that this has nothing to do with defining label *names*.
734 Languages vary in how they do that and what that even means. */
740 struct label_chain *p;
742 do_pending_stack_adjust ();
743 emit_label (label_rtx (label));
744 if (DECL_NAME (label))
745 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
747 if (stack_block_stack != 0)
749 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
750 p->next = stack_block_stack->data.block.label_chain;
751 stack_block_stack->data.block.label_chain = p;
756 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
757 from nested functions. */
760 declare_nonlocal_label (label)
763 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
765 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
766 LABEL_PRESERVE_P (label_rtx (label)) = 1;
767 if (nonlocal_goto_handler_slots == 0)
769 emit_stack_save (SAVE_NONLOCAL,
770 &nonlocal_goto_stack_level,
771 PREV_INSN (tail_recursion_reentry));
773 nonlocal_goto_handler_slots
774 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
777 /* Generate RTL code for a `goto' statement with target label LABEL.
778 LABEL should be a LABEL_DECL tree node that was or will later be
779 defined with `expand_label'. */
787 /* Check for a nonlocal goto to a containing function. */
788 context = decl_function_context (label);
789 if (context != 0 && context != current_function_decl)
791 struct function *p = find_function_data (context);
792 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
793 rtx temp, handler_slot;
796 /* Find the corresponding handler slot for this label. */
797 handler_slot = p->x_nonlocal_goto_handler_slots;
798 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
799 link = TREE_CHAIN (link))
800 handler_slot = XEXP (handler_slot, 1);
801 handler_slot = XEXP (handler_slot, 0);
803 p->has_nonlocal_label = 1;
804 current_function_has_nonlocal_goto = 1;
805 LABEL_REF_NONLOCAL_P (label_ref) = 1;
807 /* Copy the rtl for the slots so that they won't be shared in
808 case the virtual stack vars register gets instantiated differently
809 in the parent than in the child. */
811 #if HAVE_nonlocal_goto
812 if (HAVE_nonlocal_goto)
813 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
814 copy_rtx (handler_slot),
815 copy_rtx (p->x_nonlocal_goto_stack_level),
822 /* Restore frame pointer for containing function.
823 This sets the actual hard register used for the frame pointer
824 to the location of the function's incoming static chain info.
825 The non-local goto handler will then adjust it to contain the
826 proper value and reload the argument pointer, if needed. */
827 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
829 /* We have now loaded the frame pointer hardware register with
830 the address of that corresponds to the start of the virtual
831 stack vars. So replace virtual_stack_vars_rtx in all
832 addresses we use with stack_pointer_rtx. */
834 /* Get addr of containing function's current nonlocal goto handler,
835 which will do any cleanups and then jump to the label. */
836 addr = copy_rtx (handler_slot);
837 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
838 hard_frame_pointer_rtx));
840 /* Restore the stack pointer. Note this uses fp just restored. */
841 addr = p->x_nonlocal_goto_stack_level;
843 addr = replace_rtx (copy_rtx (addr),
844 virtual_stack_vars_rtx,
845 hard_frame_pointer_rtx);
847 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
849 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
851 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
852 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
853 emit_indirect_jump (temp);
857 expand_goto_internal (label, label_rtx (label), NULL_RTX);
860 /* Generate RTL code for a `goto' statement with target label BODY.
861 LABEL should be a LABEL_REF.
862 LAST_INSN, if non-0, is the rtx we should consider as the last
863 insn emitted (for the purposes of cleaning up a return). */
866 expand_goto_internal (body, label, last_insn)
871 struct nesting *block;
874 if (GET_CODE (label) != CODE_LABEL)
877 /* If label has already been defined, we can tell now
878 whether and how we must alter the stack level. */
880 if (PREV_INSN (label) != 0)
882 /* Find the innermost pending block that contains the label.
883 (Check containment by comparing insn-uids.)
884 Then restore the outermost stack level within that block,
885 and do cleanups of all blocks contained in it. */
886 for (block = block_stack; block; block = block->next)
888 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
890 if (block->data.block.stack_level != 0)
891 stack_level = block->data.block.stack_level;
892 /* Execute the cleanups for blocks we are exiting. */
893 if (block->data.block.cleanups != 0)
895 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
896 do_pending_stack_adjust ();
902 /* Ensure stack adjust isn't done by emit_jump, as this
903 would clobber the stack pointer. This one should be
904 deleted as dead by flow. */
905 clear_pending_stack_adjust ();
906 do_pending_stack_adjust ();
907 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
910 if (body != 0 && DECL_TOO_LATE (body))
911 error ("jump to `%s' invalidly jumps into binding contour",
912 IDENTIFIER_POINTER (DECL_NAME (body)));
914 /* Label not yet defined: may need to put this goto
915 on the fixup list. */
916 else if (! expand_fixup (body, label, last_insn))
918 /* No fixup needed. Record that the label is the target
919 of at least one goto that has no fixup. */
921 TREE_ADDRESSABLE (body) = 1;
927 /* Generate if necessary a fixup for a goto
928 whose target label in tree structure (if any) is TREE_LABEL
929 and whose target in rtl is RTL_LABEL.
931 If LAST_INSN is nonzero, we pretend that the jump appears
932 after insn LAST_INSN instead of at the current point in the insn stream.
934 The fixup will be used later to insert insns just before the goto.
935 Those insns will restore the stack level as appropriate for the
936 target label, and will (in the case of C++) also invoke any object
937 destructors which have to be invoked when we exit the scopes which
938 are exited by the goto.
940 Value is nonzero if a fixup is made. */
943 expand_fixup (tree_label, rtl_label, last_insn)
948 struct nesting *block, *end_block;
950 /* See if we can recognize which block the label will be output in.
951 This is possible in some very common cases.
952 If we succeed, set END_BLOCK to that block.
953 Otherwise, set it to 0. */
956 && (rtl_label == cond_stack->data.cond.endif_label
957 || rtl_label == cond_stack->data.cond.next_label))
958 end_block = cond_stack;
959 /* If we are in a loop, recognize certain labels which
960 are likely targets. This reduces the number of fixups
961 we need to create. */
963 && (rtl_label == loop_stack->data.loop.start_label
964 || rtl_label == loop_stack->data.loop.end_label
965 || rtl_label == loop_stack->data.loop.continue_label))
966 end_block = loop_stack;
970 /* Now set END_BLOCK to the binding level to which we will return. */
974 struct nesting *next_block = end_block->all;
977 /* First see if the END_BLOCK is inside the innermost binding level.
978 If so, then no cleanups or stack levels are relevant. */
979 while (next_block && next_block != block)
980 next_block = next_block->all;
985 /* Otherwise, set END_BLOCK to the innermost binding level
986 which is outside the relevant control-structure nesting. */
987 next_block = block_stack->next;
988 for (block = block_stack; block != end_block; block = block->all)
989 if (block == next_block)
990 next_block = next_block->next;
991 end_block = next_block;
994 /* Does any containing block have a stack level or cleanups?
995 If not, no fixup is needed, and that is the normal case
996 (the only case, for standard C). */
997 for (block = block_stack; block != end_block; block = block->next)
998 if (block->data.block.stack_level != 0
999 || block->data.block.cleanups != 0)
1002 if (block != end_block)
1004 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1005 struct goto_fixup *fixup
1006 = (struct goto_fixup *) ggc_alloc_obj (sizeof (struct goto_fixup), 0);
1007 /* In case an old stack level is restored, make sure that comes
1008 after any pending stack adjust. */
1009 /* ?? If the fixup isn't to come at the present position,
1010 doing the stack adjust here isn't useful. Doing it with our
1011 settings at that location isn't useful either. Let's hope
1014 do_pending_stack_adjust ();
1015 fixup->target = tree_label;
1016 fixup->target_rtl = rtl_label;
1018 /* Create a BLOCK node and a corresponding matched set of
1019 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1020 this point. The notes will encapsulate any and all fixup
1021 code which we might later insert at this point in the insn
1022 stream. Also, the BLOCK node will be the parent (i.e. the
1023 `SUPERBLOCK') of any other BLOCK nodes which we might create
1024 later on when we are expanding the fixup code.
1026 Note that optimization passes (including expand_end_loop)
1027 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1028 as a placeholder. */
1031 register rtx original_before_jump
1032 = last_insn ? last_insn : get_last_insn ();
1037 block = make_node (BLOCK);
1038 TREE_USED (block) = 1;
1040 if (!cfun->x_whole_function_mode_p)
1041 insert_block (block);
1045 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1046 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1051 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1052 if (cfun->x_whole_function_mode_p)
1053 NOTE_BLOCK (start) = block;
1054 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1055 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1056 if (cfun->x_whole_function_mode_p)
1057 NOTE_BLOCK (end) = block;
1058 fixup->context = block;
1060 emit_insns_after (start, original_before_jump);
1063 fixup->block_start_count = current_block_start_count;
1064 fixup->stack_level = 0;
1065 fixup->cleanup_list_list
1066 = ((block->data.block.outer_cleanups
1067 || block->data.block.cleanups)
1068 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1069 block->data.block.outer_cleanups)
1071 fixup->next = goto_fixup_chain;
1072 goto_fixup_chain = fixup;
1080 /* Expand any needed fixups in the outputmost binding level of the
1081 function. FIRST_INSN is the first insn in the function. */
1084 expand_fixups (first_insn)
1087 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1090 /* When exiting a binding contour, process all pending gotos requiring fixups.
1091 THISBLOCK is the structure that describes the block being exited.
1092 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1093 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1094 FIRST_INSN is the insn that began this contour.
1096 Gotos that jump out of this contour must restore the
1097 stack level and do the cleanups before actually jumping.
1099 DONT_JUMP_IN nonzero means report error there is a jump into this
1100 contour from before the beginning of the contour.
1101 This is also done if STACK_LEVEL is nonzero. */
1104 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1105 struct nesting *thisblock;
1111 register struct goto_fixup *f, *prev;
1113 /* F is the fixup we are considering; PREV is the previous one. */
1114 /* We run this loop in two passes so that cleanups of exited blocks
1115 are run first, and blocks that are exited are marked so
1118 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1120 /* Test for a fixup that is inactive because it is already handled. */
1121 if (f->before_jump == 0)
1123 /* Delete inactive fixup from the chain, if that is easy to do. */
1125 prev->next = f->next;
1127 /* Has this fixup's target label been defined?
1128 If so, we can finalize it. */
1129 else if (PREV_INSN (f->target_rtl) != 0)
1131 register rtx cleanup_insns;
1133 /* If this fixup jumped into this contour from before the beginning
1134 of this contour, report an error. This code used to use
1135 the first non-label insn after f->target_rtl, but that's
1136 wrong since such can be added, by things like put_var_into_stack
1137 and have INSN_UIDs that are out of the range of the block. */
1138 /* ??? Bug: this does not detect jumping in through intermediate
1139 blocks that have stack levels or cleanups.
1140 It detects only a problem with the innermost block
1141 around the label. */
1143 && (dont_jump_in || stack_level || cleanup_list)
1144 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1145 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1146 && ! DECL_ERROR_ISSUED (f->target))
1148 error_with_decl (f->target,
1149 "label `%s' used before containing binding contour");
1150 /* Prevent multiple errors for one label. */
1151 DECL_ERROR_ISSUED (f->target) = 1;
1154 /* We will expand the cleanups into a sequence of their own and
1155 then later on we will attach this new sequence to the insn
1156 stream just ahead of the actual jump insn. */
1160 /* Temporarily restore the lexical context where we will
1161 logically be inserting the fixup code. We do this for the
1162 sake of getting the debugging information right. */
1165 set_block (f->context);
1167 /* Expand the cleanups for blocks this jump exits. */
1168 if (f->cleanup_list_list)
1171 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1172 /* Marked elements correspond to blocks that have been closed.
1173 Do their cleanups. */
1174 if (TREE_ADDRESSABLE (lists)
1175 && TREE_VALUE (lists) != 0)
1177 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1178 /* Pop any pushes done in the cleanups,
1179 in case function is about to return. */
1180 do_pending_stack_adjust ();
1184 /* Restore stack level for the biggest contour that this
1185 jump jumps out of. */
1187 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1189 /* Finish up the sequence containing the insns which implement the
1190 necessary cleanups, and then attach that whole sequence to the
1191 insn stream just ahead of the actual jump insn. Attaching it
1192 at that point insures that any cleanups which are in fact
1193 implicit C++ object destructions (which must be executed upon
1194 leaving the block) appear (to the debugger) to be taking place
1195 in an area of the generated code where the object(s) being
1196 destructed are still "in scope". */
1198 cleanup_insns = get_insns ();
1202 emit_insns_after (cleanup_insns, f->before_jump);
1209 /* For any still-undefined labels, do the cleanups for this block now.
1210 We must do this now since items in the cleanup list may go out
1211 of scope when the block ends. */
1212 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1213 if (f->before_jump != 0
1214 && PREV_INSN (f->target_rtl) == 0
1215 /* Label has still not appeared. If we are exiting a block with
1216 a stack level to restore, that started before the fixup,
1217 mark this stack level as needing restoration
1218 when the fixup is later finalized. */
1220 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1221 means the label is undefined. That's erroneous, but possible. */
1222 && (thisblock->data.block.block_start_count
1223 <= f->block_start_count))
1225 tree lists = f->cleanup_list_list;
1228 for (; lists; lists = TREE_CHAIN (lists))
1229 /* If the following elt. corresponds to our containing block
1230 then the elt. must be for this block. */
1231 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1235 set_block (f->context);
1236 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1237 do_pending_stack_adjust ();
1238 cleanup_insns = get_insns ();
1241 if (cleanup_insns != 0)
1243 = emit_insns_after (cleanup_insns, f->before_jump);
1245 f->cleanup_list_list = TREE_CHAIN (lists);
1249 f->stack_level = stack_level;
1253 /* Return the number of times character C occurs in string S. */
1255 n_occurrences (c, s)
1265 /* Generate RTL for an asm statement (explicit assembler code).
1266 BODY is a STRING_CST node containing the assembler code text,
1267 or an ADDR_EXPR containing a STRING_CST. */
1273 if (current_function_check_memory_usage)
1275 error ("`asm' cannot be used in function where memory usage is checked");
1279 if (TREE_CODE (body) == ADDR_EXPR)
1280 body = TREE_OPERAND (body, 0);
1282 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1283 TREE_STRING_POINTER (body)));
1287 /* Generate RTL for an asm statement with arguments.
1288 STRING is the instruction template.
1289 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1290 Each output or input has an expression in the TREE_VALUE and
1291 a constraint-string in the TREE_PURPOSE.
1292 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1293 that is clobbered by this insn.
1295 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1296 Some elements of OUTPUTS may be replaced with trees representing temporary
1297 values. The caller should copy those temporary values to the originally
1300 VOL nonzero means the insn is volatile; don't optimize it. */
1303 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1304 tree string, outputs, inputs, clobbers;
1309 rtvec argvec, constraints;
1311 int ninputs = list_length (inputs);
1312 int noutputs = list_length (outputs);
1317 /* Vector of RTX's of evaluated output operands. */
1318 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1319 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1320 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1321 enum machine_mode *inout_mode
1322 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1323 /* The insn we have emitted. */
1326 /* An ASM with no outputs needs to be treated as volatile, for now. */
1330 if (current_function_check_memory_usage)
1332 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1336 #ifdef MD_ASM_CLOBBERS
1337 /* Sometimes we wish to automatically clobber registers across an asm.
1338 Case in point is when the i386 backend moved from cc0 to a hard reg --
1339 maintaining source-level compatability means automatically clobbering
1340 the flags register. */
1341 MD_ASM_CLOBBERS (clobbers);
1344 if (current_function_check_memory_usage)
1346 error ("`asm' cannot be used in function where memory usage is checked");
1350 /* Count the number of meaningful clobbered registers, ignoring what
1351 we would ignore later. */
1353 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1355 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1357 i = decode_reg_name (regname);
1358 if (i >= 0 || i == -4)
1361 error ("unknown register name `%s' in `asm'", regname);
1366 /* Check that the number of alternatives is constant across all
1368 if (outputs || inputs)
1370 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1371 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1374 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1376 error ("too many alternatives in `asm'");
1383 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1385 if (n_occurrences (',', constraint) != nalternatives)
1387 error ("operand constraints for `asm' differ in number of alternatives");
1391 if (TREE_CHAIN (tmp))
1392 tmp = TREE_CHAIN (tmp);
1394 tmp = next, next = 0;
1398 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1400 tree val = TREE_VALUE (tail);
1401 tree type = TREE_TYPE (val);
1410 /* If there's an erroneous arg, emit no insn. */
1411 if (TREE_TYPE (val) == error_mark_node)
1414 /* Make sure constraint has `=' and does not have `+'. Also, see
1415 if it allows any register. Be liberal on the latter test, since
1416 the worst that happens if we get it wrong is we issue an error
1419 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1420 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1422 /* Allow the `=' or `+' to not be at the beginning of the string,
1423 since it wasn't explicitly documented that way, and there is a
1424 large body of code that puts it last. Swap the character to
1425 the front, so as not to uglify any place else. */
1429 if ((p = strchr (constraint, '=')) != NULL)
1431 if ((p = strchr (constraint, '+')) != NULL)
1434 error ("output operand constraint lacks `='");
1438 if (p != constraint)
1441 bcopy (constraint, constraint+1, p-constraint);
1444 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1447 is_inout = constraint[0] == '+';
1448 /* Replace '+' with '='. */
1449 constraint[0] = '=';
1450 /* Make sure we can specify the matching operand. */
1451 if (is_inout && i > 9)
1453 error ("output operand constraint %d contains `+'", i);
1457 for (j = 1; j < c_len; j++)
1458 switch (constraint[j])
1462 error ("operand constraint contains '+' or '=' at illegal position.");
1466 if (i + 1 == ninputs + noutputs)
1468 error ("`%%' constraint used with last operand");
1473 case '?': case '!': case '*': case '&':
1474 case 'E': case 'F': case 'G': case 'H':
1475 case 's': case 'i': case 'n':
1476 case 'I': case 'J': case 'K': case 'L': case 'M':
1477 case 'N': case 'O': case 'P': case ',':
1478 #ifdef EXTRA_CONSTRAINT
1479 case 'Q': case 'R': case 'S': case 'T': case 'U':
1483 case '0': case '1': case '2': case '3': case '4':
1484 case '5': case '6': case '7': case '8': case '9':
1485 error ("matching constraint not valid in output operand");
1488 case 'V': case 'm': case 'o':
1493 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1494 excepting those that expand_call created. So match memory
1510 /* If an output operand is not a decl or indirect ref and our constraint
1511 allows a register, make a temporary to act as an intermediate.
1512 Make the asm insn write into that, then our caller will copy it to
1513 the real output operand. Likewise for promoted variables. */
1515 real_output_rtx[i] = NULL_RTX;
1516 if ((TREE_CODE (val) == INDIRECT_REF
1519 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1520 && ! (GET_CODE (DECL_RTL (val)) == REG
1521 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1526 mark_addressable (TREE_VALUE (tail));
1529 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1530 EXPAND_MEMORY_USE_WO);
1532 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1533 error ("output number %d not directly addressable", i);
1534 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1536 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1537 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1539 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1544 output_rtx[i] = assign_temp (type, 0, 0, 1);
1545 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1550 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1551 inout_opnum[ninout++] = i;
1556 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1558 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1562 /* Make vectors for the expression-rtx and constraint strings. */
1564 argvec = rtvec_alloc (ninputs);
1565 constraints = rtvec_alloc (ninputs);
1567 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1568 empty_string, 0, argvec, constraints,
1571 MEM_VOLATILE_P (body) = vol;
1573 /* Eval the inputs and put them into ARGVEC.
1574 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1577 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1580 int allows_reg = 0, allows_mem = 0;
1581 char *constraint, *orig_constraint;
1585 /* If there's an erroneous arg, emit no insn,
1586 because the ASM_INPUT would get VOIDmode
1587 and that could cause a crash in reload. */
1588 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1591 /* ??? Can this happen, and does the error message make any sense? */
1592 if (TREE_PURPOSE (tail) == NULL_TREE)
1594 error ("hard register `%s' listed as input operand to `asm'",
1595 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1599 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1600 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1601 orig_constraint = constraint;
1603 /* Make sure constraint has neither `=', `+', nor '&'. */
1605 for (j = 0; j < c_len; j++)
1606 switch (constraint[j])
1608 case '+': case '=': case '&':
1609 if (constraint == orig_constraint)
1611 error ("input operand constraint contains `%c'",
1618 if (constraint == orig_constraint
1619 && i + 1 == ninputs - ninout)
1621 error ("`%%' constraint used with last operand");
1626 case 'V': case 'm': case 'o':
1631 case '?': case '!': case '*':
1632 case 'E': case 'F': case 'G': case 'H': case 'X':
1633 case 's': case 'i': case 'n':
1634 case 'I': case 'J': case 'K': case 'L': case 'M':
1635 case 'N': case 'O': case 'P': case ',':
1636 #ifdef EXTRA_CONSTRAINT
1637 case 'Q': case 'R': case 'S': case 'T': case 'U':
1641 /* Whether or not a numeric constraint allows a register is
1642 decided by the matching constraint, and so there is no need
1643 to do anything special with them. We must handle them in
1644 the default case, so that we don't unnecessarily force
1645 operands to memory. */
1646 case '0': case '1': case '2': case '3': case '4':
1647 case '5': case '6': case '7': case '8': case '9':
1648 if (constraint[j] >= '0' + noutputs)
1651 ("matching constraint references invalid operand number");
1655 /* Try and find the real constraint for this dup. */
1656 if ((j == 0 && c_len == 1)
1657 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1661 for (j = constraint[j] - '0'; j > 0; --j)
1664 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1665 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1670 /* ... fall through ... */
1683 if (! allows_reg && allows_mem)
1684 mark_addressable (TREE_VALUE (tail));
1686 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1688 if (asm_operand_ok (op, constraint) <= 0)
1691 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1692 else if (!allows_mem)
1693 warning ("asm operand %d probably doesn't match constraints", i);
1694 else if (CONSTANT_P (op))
1695 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1697 else if (GET_CODE (op) == REG
1698 || GET_CODE (op) == SUBREG
1699 || GET_CODE (op) == CONCAT)
1701 tree type = TREE_TYPE (TREE_VALUE (tail));
1702 rtx memloc = assign_temp (type, 1, 1, 1);
1704 emit_move_insn (memloc, op);
1708 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1709 /* We won't recognize volatile memory as available a
1710 memory_operand at this point. Ignore it. */
1712 else if (queued_subexp_p (op))
1715 /* ??? Leave this only until we have experience with what
1716 happens in combine and elsewhere when constraints are
1718 warning ("asm operand %d probably doesn't match constraints", i);
1720 XVECEXP (body, 3, i) = op;
1722 XVECEXP (body, 4, i) /* constraints */
1723 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1728 /* Protect all the operands from the queue now that they have all been
1731 for (i = 0; i < ninputs - ninout; i++)
1732 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1734 for (i = 0; i < noutputs; i++)
1735 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1737 /* For in-out operands, copy output rtx to input rtx. */
1738 for (i = 0; i < ninout; i++)
1740 int j = inout_opnum[i];
1742 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1744 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1745 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1748 /* Now, for each output, construct an rtx
1749 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1750 ARGVEC CONSTRAINTS))
1751 If there is more than one, put them inside a PARALLEL. */
1753 if (noutputs == 1 && nclobbers == 0)
1755 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1756 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1759 else if (noutputs == 0 && nclobbers == 0)
1761 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1762 insn = emit_insn (body);
1773 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1775 /* For each output operand, store a SET. */
1776 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1778 XVECEXP (body, 0, i)
1779 = gen_rtx_SET (VOIDmode,
1781 gen_rtx_ASM_OPERANDS
1783 TREE_STRING_POINTER (string),
1784 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1785 i, argvec, constraints,
1788 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1791 /* If there are no outputs (but there are some clobbers)
1792 store the bare ASM_OPERANDS into the PARALLEL. */
1795 XVECEXP (body, 0, i++) = obody;
1797 /* Store (clobber REG) for each clobbered register specified. */
1799 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1801 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1802 int j = decode_reg_name (regname);
1806 if (j == -3) /* `cc', which is not a register */
1809 if (j == -4) /* `memory', don't cache memory across asm */
1811 XVECEXP (body, 0, i++)
1812 = gen_rtx_CLOBBER (VOIDmode,
1815 gen_rtx_SCRATCH (VOIDmode)));
1819 /* Ignore unknown register, error already signaled. */
1823 /* Use QImode since that's guaranteed to clobber just one reg. */
1824 XVECEXP (body, 0, i++)
1825 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1828 insn = emit_insn (body);
1831 /* For any outputs that needed reloading into registers, spill them
1832 back to where they belong. */
1833 for (i = 0; i < noutputs; ++i)
1834 if (real_output_rtx[i])
1835 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1840 /* Generate RTL to evaluate the expression EXP
1841 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1844 expand_expr_stmt (exp)
1847 /* If -W, warn about statements with no side effects,
1848 except for an explicit cast to void (e.g. for assert()), and
1849 except inside a ({...}) where they may be useful. */
1850 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1852 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1853 && !(TREE_CODE (exp) == CONVERT_EXPR
1854 && TREE_TYPE (exp) == void_type_node))
1855 warning_with_file_and_line (emit_filename, emit_lineno,
1856 "statement with no effect");
1857 else if (warn_unused)
1858 warn_if_unused_value (exp);
1861 /* If EXP is of function type and we are expanding statements for
1862 value, convert it to pointer-to-function. */
1863 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1864 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1866 last_expr_type = TREE_TYPE (exp);
1867 last_expr_value = expand_expr (exp,
1868 (expr_stmts_for_value
1869 ? NULL_RTX : const0_rtx),
1872 /* If all we do is reference a volatile value in memory,
1873 copy it to a register to be sure it is actually touched. */
1874 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1875 && TREE_THIS_VOLATILE (exp))
1877 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1879 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1880 copy_to_reg (last_expr_value);
1883 rtx lab = gen_label_rtx ();
1885 /* Compare the value with itself to reference it. */
1886 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1887 expand_expr (TYPE_SIZE (last_expr_type),
1888 NULL_RTX, VOIDmode, 0),
1890 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1896 /* If this expression is part of a ({...}) and is in memory, we may have
1897 to preserve temporaries. */
1898 preserve_temp_slots (last_expr_value);
1900 /* Free any temporaries used to evaluate this expression. Any temporary
1901 used as a result of this expression will already have been preserved
1908 /* Warn if EXP contains any computations whose results are not used.
1909 Return 1 if a warning is printed; 0 otherwise. */
1912 warn_if_unused_value (exp)
1915 if (TREE_USED (exp))
1918 switch (TREE_CODE (exp))
1920 case PREINCREMENT_EXPR:
1921 case POSTINCREMENT_EXPR:
1922 case PREDECREMENT_EXPR:
1923 case POSTDECREMENT_EXPR:
1928 case METHOD_CALL_EXPR:
1930 case TRY_CATCH_EXPR:
1931 case WITH_CLEANUP_EXPR:
1933 /* We don't warn about COND_EXPR because it may be a useful
1934 construct if either arm contains a side effect. */
1939 /* For a binding, warn if no side effect within it. */
1940 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1943 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1945 case TRUTH_ORIF_EXPR:
1946 case TRUTH_ANDIF_EXPR:
1947 /* In && or ||, warn if 2nd operand has no side effect. */
1948 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1951 if (TREE_NO_UNUSED_WARNING (exp))
1953 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1955 /* Let people do `(foo (), 0)' without a warning. */
1956 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1958 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1962 case NON_LVALUE_EXPR:
1963 /* Don't warn about values cast to void. */
1964 if (TREE_TYPE (exp) == void_type_node)
1966 /* Don't warn about conversions not explicit in the user's program. */
1967 if (TREE_NO_UNUSED_WARNING (exp))
1969 /* Assignment to a cast usually results in a cast of a modify.
1970 Don't complain about that. There can be an arbitrary number of
1971 casts before the modify, so we must loop until we find the first
1972 non-cast expression and then test to see if that is a modify. */
1974 tree tem = TREE_OPERAND (exp, 0);
1976 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1977 tem = TREE_OPERAND (tem, 0);
1979 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1980 || TREE_CODE (tem) == CALL_EXPR)
1986 /* Don't warn about automatic dereferencing of references, since
1987 the user cannot control it. */
1988 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1989 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1990 /* ... fall through ... */
1993 /* Referencing a volatile value is a side effect, so don't warn. */
1995 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1996 && TREE_THIS_VOLATILE (exp))
1999 warning_with_file_and_line (emit_filename, emit_lineno,
2000 "value computed is not used");
2005 /* Clear out the memory of the last expression evaluated. */
2013 /* Begin a statement which will return a value.
2014 Return the RTL_EXPR for this statement expr.
2015 The caller must save that value and pass it to expand_end_stmt_expr. */
2018 expand_start_stmt_expr ()
2023 /* Make the RTL_EXPR node temporary, not momentary,
2024 so that rtl_expr_chain doesn't become garbage. */
2025 momentary = suspend_momentary ();
2026 t = make_node (RTL_EXPR);
2027 resume_momentary (momentary);
2028 do_pending_stack_adjust ();
2029 start_sequence_for_rtl_expr (t);
2031 expr_stmts_for_value++;
2035 /* Restore the previous state at the end of a statement that returns a value.
2036 Returns a tree node representing the statement's value and the
2037 insns to compute the value.
2039 The nodes of that expression have been freed by now, so we cannot use them.
2040 But we don't want to do that anyway; the expression has already been
2041 evaluated and now we just want to use the value. So generate a RTL_EXPR
2042 with the proper type and RTL value.
2044 If the last substatement was not an expression,
2045 return something with type `void'. */
2048 expand_end_stmt_expr (t)
2053 if (last_expr_type == 0)
2055 last_expr_type = void_type_node;
2056 last_expr_value = const0_rtx;
2058 else if (last_expr_value == 0)
2059 /* There are some cases where this can happen, such as when the
2060 statement is void type. */
2061 last_expr_value = const0_rtx;
2062 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2063 /* Remove any possible QUEUED. */
2064 last_expr_value = protect_from_queue (last_expr_value, 0);
2068 TREE_TYPE (t) = last_expr_type;
2069 RTL_EXPR_RTL (t) = last_expr_value;
2070 RTL_EXPR_SEQUENCE (t) = get_insns ();
2072 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2076 /* Don't consider deleting this expr or containing exprs at tree level. */
2077 TREE_SIDE_EFFECTS (t) = 1;
2078 /* Propagate volatility of the actual RTL expr. */
2079 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2082 expr_stmts_for_value--;
2087 /* Generate RTL for the start of an if-then. COND is the expression
2088 whose truth should be tested.
2090 If EXITFLAG is nonzero, this conditional is visible to
2091 `exit_something'. */
2094 expand_start_cond (cond, exitflag)
2098 struct nesting *thiscond = ALLOC_NESTING ();
2100 /* Make an entry on cond_stack for the cond we are entering. */
2102 thiscond->next = cond_stack;
2103 thiscond->all = nesting_stack;
2104 thiscond->depth = ++nesting_depth;
2105 thiscond->data.cond.next_label = gen_label_rtx ();
2106 /* Before we encounter an `else', we don't need a separate exit label
2107 unless there are supposed to be exit statements
2108 to exit this conditional. */
2109 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2110 thiscond->data.cond.endif_label = thiscond->exit_label;
2111 cond_stack = thiscond;
2112 nesting_stack = thiscond;
2114 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2117 /* Generate RTL between then-clause and the elseif-clause
2118 of an if-then-elseif-.... */
2121 expand_start_elseif (cond)
2124 if (cond_stack->data.cond.endif_label == 0)
2125 cond_stack->data.cond.endif_label = gen_label_rtx ();
2126 emit_jump (cond_stack->data.cond.endif_label);
2127 emit_label (cond_stack->data.cond.next_label);
2128 cond_stack->data.cond.next_label = gen_label_rtx ();
2129 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2132 /* Generate RTL between the then-clause and the else-clause
2133 of an if-then-else. */
2136 expand_start_else ()
2138 if (cond_stack->data.cond.endif_label == 0)
2139 cond_stack->data.cond.endif_label = gen_label_rtx ();
2141 emit_jump (cond_stack->data.cond.endif_label);
2142 emit_label (cond_stack->data.cond.next_label);
2143 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2146 /* After calling expand_start_else, turn this "else" into an "else if"
2147 by providing another condition. */
2150 expand_elseif (cond)
2153 cond_stack->data.cond.next_label = gen_label_rtx ();
2154 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2157 /* Generate RTL for the end of an if-then.
2158 Pop the record for it off of cond_stack. */
2163 struct nesting *thiscond = cond_stack;
2165 do_pending_stack_adjust ();
2166 if (thiscond->data.cond.next_label)
2167 emit_label (thiscond->data.cond.next_label);
2168 if (thiscond->data.cond.endif_label)
2169 emit_label (thiscond->data.cond.endif_label);
2171 POPSTACK (cond_stack);
2177 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2178 loop should be exited by `exit_something'. This is a loop for which
2179 `expand_continue' will jump to the top of the loop.
2181 Make an entry on loop_stack to record the labels associated with
2185 expand_start_loop (exit_flag)
2188 register struct nesting *thisloop = ALLOC_NESTING ();
2190 /* Make an entry on loop_stack for the loop we are entering. */
2192 thisloop->next = loop_stack;
2193 thisloop->all = nesting_stack;
2194 thisloop->depth = ++nesting_depth;
2195 thisloop->data.loop.start_label = gen_label_rtx ();
2196 thisloop->data.loop.end_label = gen_label_rtx ();
2197 thisloop->data.loop.alt_end_label = 0;
2198 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2199 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2200 loop_stack = thisloop;
2201 nesting_stack = thisloop;
2203 do_pending_stack_adjust ();
2205 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2206 emit_label (thisloop->data.loop.start_label);
2211 /* Like expand_start_loop but for a loop where the continuation point
2212 (for expand_continue_loop) will be specified explicitly. */
2215 expand_start_loop_continue_elsewhere (exit_flag)
2218 struct nesting *thisloop = expand_start_loop (exit_flag);
2219 loop_stack->data.loop.continue_label = gen_label_rtx ();
2223 /* Specify the continuation point for a loop started with
2224 expand_start_loop_continue_elsewhere.
2225 Use this at the point in the code to which a continue statement
2229 expand_loop_continue_here ()
2231 do_pending_stack_adjust ();
2232 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2233 emit_label (loop_stack->data.loop.continue_label);
2236 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2237 Pop the block off of loop_stack. */
2242 rtx start_label = loop_stack->data.loop.start_label;
2243 rtx insn = get_last_insn ();
2244 int needs_end_jump = 1;
2246 /* Mark the continue-point at the top of the loop if none elsewhere. */
2247 if (start_label == loop_stack->data.loop.continue_label)
2248 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2250 do_pending_stack_adjust ();
2252 /* If optimizing, perhaps reorder the loop.
2253 First, try to use a condjump near the end.
2254 expand_exit_loop_if_false ends loops with unconditional jumps,
2257 if (test) goto label;
2259 goto loop_stack->data.loop.end_label
2263 If we find such a pattern, we can end the loop earlier. */
2266 && GET_CODE (insn) == CODE_LABEL
2267 && LABEL_NAME (insn) == NULL
2268 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2271 rtx jump = PREV_INSN (PREV_INSN (label));
2273 if (GET_CODE (jump) == JUMP_INSN
2274 && GET_CODE (PATTERN (jump)) == SET
2275 && SET_DEST (PATTERN (jump)) == pc_rtx
2276 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2277 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2278 == loop_stack->data.loop.end_label))
2282 /* The test might be complex and reference LABEL multiple times,
2283 like the loop in loop_iterations to set vtop. To handle this,
2285 insn = PREV_INSN (label);
2286 reorder_insns (label, label, start_label);
2288 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2290 /* We ignore line number notes, but if we see any other note,
2291 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2292 NOTE_INSN_LOOP_*, we disable this optimization. */
2293 if (GET_CODE (prev) == NOTE)
2295 if (NOTE_LINE_NUMBER (prev) < 0)
2299 if (GET_CODE (prev) == CODE_LABEL)
2301 if (GET_CODE (prev) == JUMP_INSN)
2303 if (GET_CODE (PATTERN (prev)) == SET
2304 && SET_DEST (PATTERN (prev)) == pc_rtx
2305 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2306 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2308 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2310 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2312 emit_note_after (NOTE_INSN_LOOP_END, prev);
2321 /* If the loop starts with a loop exit, roll that to the end where
2322 it will optimize together with the jump back.
2324 We look for the conditional branch to the exit, except that once
2325 we find such a branch, we don't look past 30 instructions.
2327 In more detail, if the loop presently looks like this (in pseudo-C):
2330 if (test) goto end_label;
2335 transform it to look like:
2341 if (test) goto end_label;
2342 goto newstart_label;
2345 Here, the `test' may actually consist of some reasonably complex
2346 code, terminating in a test. */
2351 ! (GET_CODE (insn) == JUMP_INSN
2352 && GET_CODE (PATTERN (insn)) == SET
2353 && SET_DEST (PATTERN (insn)) == pc_rtx
2354 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2358 rtx last_test_insn = NULL_RTX;
2360 /* Scan insns from the top of the loop looking for a qualified
2361 conditional exit. */
2362 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2363 insn = NEXT_INSN (insn))
2365 if (GET_CODE (insn) == NOTE)
2368 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2369 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2370 /* The code that actually moves the exit test will
2371 carefully leave BLOCK notes in their original
2372 location. That means, however, that we can't debug
2373 the exit test itself. So, we refuse to move code
2374 containing BLOCK notes at low optimization levels. */
2377 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2379 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2383 /* We've come to the end of an EH region, but
2384 never saw the beginning of that region. That
2385 means that an EH region begins before the top
2386 of the loop, and ends in the middle of it. The
2387 existence of such a situation violates a basic
2388 assumption in this code, since that would imply
2389 that even when EH_REGIONS is zero, we might
2390 move code out of an exception region. */
2394 /* We must not walk into a nested loop. */
2395 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2398 /* We already know this INSN is a NOTE, so there's no
2399 point in looking at it to see if it's a JUMP. */
2403 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2406 if (last_test_insn && num_insns > 30)
2410 /* We don't want to move a partial EH region. Consider:
2424 This isn't legal C++, but here's what it's supposed to
2425 mean: if cond() is true, stop looping. Otherwise,
2426 call bar, and keep looping. In addition, if cond
2427 throws an exception, catch it and keep looping. Such
2428 constructs are certainy legal in LISP.
2430 We should not move the `if (cond()) 0' test since then
2431 the EH-region for the try-block would be broken up.
2432 (In this case we would the EH_BEG note for the `try'
2433 and `if cond()' but not the call to bar() or the
2436 So we don't look for tests within an EH region. */
2439 if (GET_CODE (insn) == JUMP_INSN
2440 && GET_CODE (PATTERN (insn)) == SET
2441 && SET_DEST (PATTERN (insn)) == pc_rtx)
2443 /* This is indeed a jump. */
2444 rtx dest1 = NULL_RTX;
2445 rtx dest2 = NULL_RTX;
2446 rtx potential_last_test;
2447 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2449 /* A conditional jump. */
2450 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2451 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2452 potential_last_test = insn;
2456 /* An unconditional jump. */
2457 dest1 = SET_SRC (PATTERN (insn));
2458 /* Include the BARRIER after the JUMP. */
2459 potential_last_test = NEXT_INSN (insn);
2463 if (dest1 && GET_CODE (dest1) == LABEL_REF
2464 && ((XEXP (dest1, 0)
2465 == loop_stack->data.loop.alt_end_label)
2467 == loop_stack->data.loop.end_label)))
2469 last_test_insn = potential_last_test;
2473 /* If this was a conditional jump, there may be
2474 another label at which we should look. */
2481 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2483 /* We found one. Move everything from there up
2484 to the end of the loop, and add a jump into the loop
2485 to jump to there. */
2486 register rtx newstart_label = gen_label_rtx ();
2487 register rtx start_move = start_label;
2490 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2491 then we want to move this note also. */
2492 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2493 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2494 == NOTE_INSN_LOOP_CONT))
2495 start_move = PREV_INSN (start_move);
2497 emit_label_after (newstart_label, PREV_INSN (start_move));
2499 /* Actually move the insns. Start at the beginning, and
2500 keep copying insns until we've copied the
2502 for (insn = start_move; insn; insn = next_insn)
2504 /* Figure out which insn comes after this one. We have
2505 to do this before we move INSN. */
2506 if (insn == last_test_insn)
2507 /* We've moved all the insns. */
2508 next_insn = NULL_RTX;
2510 next_insn = NEXT_INSN (insn);
2512 if (GET_CODE (insn) == NOTE
2513 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2514 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2515 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2516 NOTE_INSN_BLOCK_ENDs because the correct generation
2517 of debugging information depends on these appearing
2518 in the same order in the RTL and in the tree
2519 structure, where they are represented as BLOCKs.
2520 So, we don't move block notes. Of course, moving
2521 the code inside the block is likely to make it
2522 impossible to debug the instructions in the exit
2523 test, but such is the price of optimization. */
2526 /* Move the INSN. */
2527 reorder_insns (insn, insn, get_last_insn ());
2530 emit_jump_insn_after (gen_jump (start_label),
2531 PREV_INSN (newstart_label));
2532 emit_barrier_after (PREV_INSN (newstart_label));
2533 start_label = newstart_label;
2539 emit_jump (start_label);
2540 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2542 emit_label (loop_stack->data.loop.end_label);
2544 POPSTACK (loop_stack);
2549 /* Generate a jump to the current loop's continue-point.
2550 This is usually the top of the loop, but may be specified
2551 explicitly elsewhere. If not currently inside a loop,
2552 return 0 and do nothing; caller will print an error message. */
2555 expand_continue_loop (whichloop)
2556 struct nesting *whichloop;
2560 whichloop = loop_stack;
2563 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2568 /* Generate a jump to exit the current loop. If not currently inside a loop,
2569 return 0 and do nothing; caller will print an error message. */
2572 expand_exit_loop (whichloop)
2573 struct nesting *whichloop;
2577 whichloop = loop_stack;
2580 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2584 /* Generate a conditional jump to exit the current loop if COND
2585 evaluates to zero. If not currently inside a loop,
2586 return 0 and do nothing; caller will print an error message. */
2589 expand_exit_loop_if_false (whichloop, cond)
2590 struct nesting *whichloop;
2593 rtx label = gen_label_rtx ();
2598 whichloop = loop_stack;
2601 /* In order to handle fixups, we actually create a conditional jump
2602 around a unconditional branch to exit the loop. If fixups are
2603 necessary, they go before the unconditional branch. */
2606 do_jump (cond, NULL_RTX, label);
2607 last_insn = get_last_insn ();
2608 if (GET_CODE (last_insn) == CODE_LABEL)
2609 whichloop->data.loop.alt_end_label = last_insn;
2610 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2617 /* Return nonzero if the loop nest is empty. Else return zero. */
2620 stmt_loop_nest_empty ()
2622 /* cfun->stmt can be NULL if we are building a call to get the
2623 EH context for a setjmp/longjmp EH target and the current
2624 function was a deferred inline function. */
2625 return (cfun->stmt == NULL || loop_stack == NULL);
2628 /* Return non-zero if we should preserve sub-expressions as separate
2629 pseudos. We never do so if we aren't optimizing. We always do so
2630 if -fexpensive-optimizations.
2632 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2633 the loop may still be a small one. */
2636 preserve_subexpressions_p ()
2640 if (flag_expensive_optimizations)
2643 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2646 insn = get_last_insn_anywhere ();
2649 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2650 < n_non_fixed_regs * 3));
2654 /* Generate a jump to exit the current loop, conditional, binding contour
2655 or case statement. Not all such constructs are visible to this function,
2656 only those started with EXIT_FLAG nonzero. Individual languages use
2657 the EXIT_FLAG parameter to control which kinds of constructs you can
2660 If not currently inside anything that can be exited,
2661 return 0 and do nothing; caller will print an error message. */
2664 expand_exit_something ()
2668 for (n = nesting_stack; n; n = n->all)
2669 if (n->exit_label != 0)
2671 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2678 /* Generate RTL to return from the current function, with no value.
2679 (That is, we do not do anything about returning any value.) */
2682 expand_null_return ()
2684 struct nesting *block = block_stack;
2685 rtx last_insn = get_last_insn ();
2687 /* If this function was declared to return a value, but we
2688 didn't, clobber the return registers so that they are not
2689 propogated live to the rest of the function. */
2690 clobber_return_register ();
2692 /* Does any pending block have cleanups? */
2693 while (block && block->data.block.cleanups == 0)
2694 block = block->next;
2696 /* If yes, use a goto to return, since that runs cleanups. */
2698 expand_null_return_1 (last_insn, block != 0);
2701 /* Generate RTL to return from the current function, with value VAL. */
2704 expand_value_return (val)
2707 struct nesting *block = block_stack;
2708 rtx last_insn = get_last_insn ();
2709 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2711 /* Copy the value to the return location
2712 unless it's already there. */
2714 if (return_reg != val)
2716 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2717 #ifdef PROMOTE_FUNCTION_RETURN
2718 int unsignedp = TREE_UNSIGNED (type);
2719 enum machine_mode old_mode
2720 = DECL_MODE (DECL_RESULT (current_function_decl));
2721 enum machine_mode mode
2722 = promote_mode (type, old_mode, &unsignedp, 1);
2724 if (mode != old_mode)
2725 val = convert_modes (mode, old_mode, val, unsignedp);
2727 if (GET_CODE (return_reg) == PARALLEL)
2728 emit_group_load (return_reg, val, int_size_in_bytes (type),
2731 emit_move_insn (return_reg, val);
2734 /* Does any pending block have cleanups? */
2736 while (block && block->data.block.cleanups == 0)
2737 block = block->next;
2739 /* If yes, use a goto to return, since that runs cleanups.
2740 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2742 expand_null_return_1 (last_insn, block != 0);
2745 /* Output a return with no value. If LAST_INSN is nonzero,
2746 pretend that the return takes place after LAST_INSN.
2747 If USE_GOTO is nonzero then don't use a return instruction;
2748 go to the return label instead. This causes any cleanups
2749 of pending blocks to be executed normally. */
2752 expand_null_return_1 (last_insn, use_goto)
2756 rtx end_label = cleanup_label ? cleanup_label : return_label;
2758 clear_pending_stack_adjust ();
2759 do_pending_stack_adjust ();
2762 /* PCC-struct return always uses an epilogue. */
2763 if (current_function_returns_pcc_struct || use_goto)
2766 end_label = return_label = gen_label_rtx ();
2767 expand_goto_internal (NULL_TREE, end_label, last_insn);
2771 /* Otherwise output a simple return-insn if one is available,
2772 unless it won't do the job. */
2774 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2776 emit_jump_insn (gen_return ());
2782 /* Otherwise jump to the epilogue. */
2783 expand_goto_internal (NULL_TREE, end_label, last_insn);
2786 /* Generate RTL to evaluate the expression RETVAL and return it
2787 from the current function. */
2790 expand_return (retval)
2793 /* If there are any cleanups to be performed, then they will
2794 be inserted following LAST_INSN. It is desirable
2795 that the last_insn, for such purposes, should be the
2796 last insn before computing the return value. Otherwise, cleanups
2797 which call functions can clobber the return value. */
2798 /* ??? rms: I think that is erroneous, because in C++ it would
2799 run destructors on variables that might be used in the subsequent
2800 computation of the return value. */
2802 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2803 register rtx val = 0;
2810 /* If function wants no value, give it none. */
2811 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2813 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2815 expand_null_return ();
2819 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2820 /* This is not sufficient. We also need to watch for cleanups of the
2821 expression we are about to expand. Unfortunately, we cannot know
2822 if it has cleanups until we expand it, and we want to change how we
2823 expand it depending upon if we need cleanups. We can't win. */
2825 cleanups = any_pending_cleanups (1);
2830 if (TREE_CODE (retval) == RESULT_DECL)
2831 retval_rhs = retval;
2832 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2833 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2834 retval_rhs = TREE_OPERAND (retval, 1);
2835 else if (TREE_TYPE (retval) == void_type_node)
2836 /* Recognize tail-recursive call to void function. */
2837 retval_rhs = retval;
2839 retval_rhs = NULL_TREE;
2841 /* Only use `last_insn' if there are cleanups which must be run. */
2842 if (cleanups || cleanup_label != 0)
2843 last_insn = get_last_insn ();
2845 /* Distribute return down conditional expr if either of the sides
2846 may involve tail recursion (see test below). This enhances the number
2847 of tail recursions we see. Don't do this always since it can produce
2848 sub-optimal code in some cases and we distribute assignments into
2849 conditional expressions when it would help. */
2851 if (optimize && retval_rhs != 0
2852 && frame_offset == 0
2853 && TREE_CODE (retval_rhs) == COND_EXPR
2854 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2855 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2857 rtx label = gen_label_rtx ();
2860 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2861 start_cleanup_deferral ();
2862 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2863 DECL_RESULT (current_function_decl),
2864 TREE_OPERAND (retval_rhs, 1));
2865 TREE_SIDE_EFFECTS (expr) = 1;
2866 expand_return (expr);
2869 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2870 DECL_RESULT (current_function_decl),
2871 TREE_OPERAND (retval_rhs, 2));
2872 TREE_SIDE_EFFECTS (expr) = 1;
2873 expand_return (expr);
2874 end_cleanup_deferral ();
2878 /* Attempt to optimize the call if it is tail recursive. */
2879 if (flag_optimize_sibling_calls
2880 && retval_rhs != NULL_TREE
2881 && frame_offset == 0
2882 && TREE_CODE (retval_rhs) == CALL_EXPR
2883 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2884 && (TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0)
2885 == current_function_decl)
2886 && optimize_tail_recursion (TREE_OPERAND (retval_rhs, 1), last_insn))
2890 /* This optimization is safe if there are local cleanups
2891 because expand_null_return takes care of them.
2892 ??? I think it should also be safe when there is a cleanup label,
2893 because expand_null_return takes care of them, too.
2894 Any reason why not? */
2895 if (HAVE_return && cleanup_label == 0
2896 && ! current_function_returns_pcc_struct
2897 && BRANCH_COST <= 1)
2899 /* If this is return x == y; then generate
2900 if (x == y) return 1; else return 0;
2901 if we can do it with explicit return insns and branches are cheap,
2902 but not if we have the corresponding scc insn. */
2905 switch (TREE_CODE (retval_rhs))
2931 case TRUTH_ANDIF_EXPR:
2932 case TRUTH_ORIF_EXPR:
2933 case TRUTH_AND_EXPR:
2935 case TRUTH_NOT_EXPR:
2936 case TRUTH_XOR_EXPR:
2939 op0 = gen_label_rtx ();
2940 jumpifnot (retval_rhs, op0);
2941 expand_value_return (const1_rtx);
2943 expand_value_return (const0_rtx);
2952 #endif /* HAVE_return */
2954 /* If the result is an aggregate that is being returned in one (or more)
2955 registers, load the registers here. The compiler currently can't handle
2956 copying a BLKmode value into registers. We could put this code in a
2957 more general area (for use by everyone instead of just function
2958 call/return), but until this feature is generally usable it is kept here
2959 (and in expand_call). The value must go into a pseudo in case there
2960 are cleanups that will clobber the real return register. */
2963 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2964 && GET_CODE (result_rtl) == REG)
2967 unsigned HOST_WIDE_INT bitpos, xbitpos;
2968 unsigned HOST_WIDE_INT big_endian_correction = 0;
2969 unsigned HOST_WIDE_INT bytes
2970 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2971 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2972 unsigned int bitsize
2973 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2974 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2975 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2976 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2977 enum machine_mode tmpmode, result_reg_mode;
2979 /* Structures whose size is not a multiple of a word are aligned
2980 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2981 machine, this means we must skip the empty high order bytes when
2982 calculating the bit offset. */
2983 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2984 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2987 /* Copy the structure BITSIZE bits at a time. */
2988 for (bitpos = 0, xbitpos = big_endian_correction;
2989 bitpos < bytes * BITS_PER_UNIT;
2990 bitpos += bitsize, xbitpos += bitsize)
2992 /* We need a new destination pseudo each time xbitpos is
2993 on a word boundary and when xbitpos == big_endian_correction
2994 (the first time through). */
2995 if (xbitpos % BITS_PER_WORD == 0
2996 || xbitpos == big_endian_correction)
2998 /* Generate an appropriate register. */
2999 dst = gen_reg_rtx (word_mode);
3000 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3002 /* Clobber the destination before we move anything into it. */
3003 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3006 /* We need a new source operand each time bitpos is on a word
3008 if (bitpos % BITS_PER_WORD == 0)
3009 src = operand_subword_force (result_val,
3010 bitpos / BITS_PER_WORD,
3013 /* Use bitpos for the source extraction (left justified) and
3014 xbitpos for the destination store (right justified). */
3015 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3016 extract_bit_field (src, bitsize,
3017 bitpos % BITS_PER_WORD, 1,
3018 NULL_RTX, word_mode, word_mode,
3019 bitsize, BITS_PER_WORD),
3020 bitsize, BITS_PER_WORD);
3023 /* Find the smallest integer mode large enough to hold the
3024 entire structure and use that mode instead of BLKmode
3025 on the USE insn for the return register. */
3026 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3027 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3028 tmpmode != VOIDmode;
3029 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3031 /* Have we found a large enough mode? */
3032 if (GET_MODE_SIZE (tmpmode) >= bytes)
3036 /* No suitable mode found. */
3037 if (tmpmode == VOIDmode)
3040 PUT_MODE (result_rtl, tmpmode);
3042 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3043 result_reg_mode = word_mode;
3045 result_reg_mode = tmpmode;
3046 result_reg = gen_reg_rtx (result_reg_mode);
3049 for (i = 0; i < n_regs; i++)
3050 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3053 if (tmpmode != result_reg_mode)
3054 result_reg = gen_lowpart (tmpmode, result_reg);
3056 expand_value_return (result_reg);
3060 && TREE_TYPE (retval_rhs) != void_type_node
3061 && (GET_CODE (result_rtl) == REG
3062 || (GET_CODE (result_rtl) == PARALLEL)))
3064 /* Calculate the return value into a temporary (usually a pseudo
3066 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3068 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3069 val = force_not_mem (val);
3071 /* Return the calculated value, doing cleanups first. */
3072 expand_value_return (val);
3076 /* No cleanups or no hard reg used;
3077 calculate value into hard return reg. */
3078 expand_expr (retval, const0_rtx, VOIDmode, 0);
3080 expand_value_return (result_rtl);
3084 /* Return 1 if the end of the generated RTX is not a barrier.
3085 This means code already compiled can drop through. */
3088 drop_through_at_end_p ()
3090 rtx insn = get_last_insn ();
3091 while (insn && GET_CODE (insn) == NOTE)
3092 insn = PREV_INSN (insn);
3093 return insn && GET_CODE (insn) != BARRIER;
3096 /* Attempt to optimize a potential tail recursion call into a goto.
3097 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3098 where to place the jump to the tail recursion label.
3100 Return TRUE if the call was optimized into a goto. */
3103 optimize_tail_recursion (arguments, last_insn)
3107 /* Finish checking validity, and if valid emit code to set the
3108 argument variables for the new call. */
3109 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3111 if (tail_recursion_label == 0)
3113 tail_recursion_label = gen_label_rtx ();
3114 emit_label_after (tail_recursion_label,
3115 tail_recursion_reentry);
3118 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3125 /* Emit code to alter this function's formal parms for a tail-recursive call.
3126 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3127 FORMALS is the chain of decls of formals.
3128 Return 1 if this can be done;
3129 otherwise return 0 and do not emit any code. */
3132 tail_recursion_args (actuals, formals)
3133 tree actuals, formals;
3135 register tree a = actuals, f = formals;
3137 register rtx *argvec;
3139 /* Check that number and types of actuals are compatible
3140 with the formals. This is not always true in valid C code.
3141 Also check that no formal needs to be addressable
3142 and that all formals are scalars. */
3144 /* Also count the args. */
3146 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3148 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3149 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3151 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3154 if (a != 0 || f != 0)
3157 /* Compute all the actuals. */
3159 argvec = (rtx *) alloca (i * sizeof (rtx));
3161 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3162 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3164 /* Find which actual values refer to current values of previous formals.
3165 Copy each of them now, before any formal is changed. */
3167 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3171 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3172 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3173 { copy = 1; break; }
3175 argvec[i] = copy_to_reg (argvec[i]);
3178 /* Store the values of the actuals into the formals. */
3180 for (f = formals, a = actuals, i = 0; f;
3181 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3183 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3184 emit_move_insn (DECL_RTL (f), argvec[i]);
3186 convert_move (DECL_RTL (f), argvec[i],
3187 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3194 /* Generate the RTL code for entering a binding contour.
3195 The variables are declared one by one, by calls to `expand_decl'.
3197 FLAGS is a bitwise or of the following flags:
3199 1 - Nonzero if this construct should be visible to
3202 2 - Nonzero if this contour does not require a
3203 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3204 language-independent code should set this flag because they
3205 will not create corresponding BLOCK nodes. (There should be
3206 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3207 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3208 when expand_end_bindings is called.
3210 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3211 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3215 expand_start_bindings_and_block (flags, block)
3219 struct nesting *thisblock = ALLOC_NESTING ();
3221 int exit_flag = ((flags & 1) != 0);
3222 int block_flag = ((flags & 2) == 0);
3224 /* If a BLOCK is supplied, then the caller should be requesting a
3225 NOTE_INSN_BLOCK_BEG note. */
3226 if (!block_flag && block)
3229 /* Create a note to mark the beginning of the block. */
3232 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3233 NOTE_BLOCK (note) = block;
3236 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3238 /* Make an entry on block_stack for the block we are entering. */
3240 thisblock->next = block_stack;
3241 thisblock->all = nesting_stack;
3242 thisblock->depth = ++nesting_depth;
3243 thisblock->data.block.stack_level = 0;
3244 thisblock->data.block.cleanups = 0;
3245 thisblock->data.block.n_function_calls = 0;
3246 thisblock->data.block.exception_region = 0;
3247 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3249 thisblock->data.block.conditional_code = 0;
3250 thisblock->data.block.last_unconditional_cleanup = note;
3251 /* When we insert instructions after the last unconditional cleanup,
3252 we don't adjust last_insn. That means that a later add_insn will
3253 clobber the instructions we've just added. The easiest way to
3254 fix this is to just insert another instruction here, so that the
3255 instructions inserted after the last unconditional cleanup are
3256 never the last instruction. */
3257 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3258 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3261 && !(block_stack->data.block.cleanups == NULL_TREE
3262 && block_stack->data.block.outer_cleanups == NULL_TREE))
3263 thisblock->data.block.outer_cleanups
3264 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3265 block_stack->data.block.outer_cleanups);
3267 thisblock->data.block.outer_cleanups = 0;
3268 thisblock->data.block.label_chain = 0;
3269 thisblock->data.block.innermost_stack_block = stack_block_stack;
3270 thisblock->data.block.first_insn = note;
3271 thisblock->data.block.block_start_count = ++current_block_start_count;
3272 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3273 block_stack = thisblock;
3274 nesting_stack = thisblock;
3276 /* Make a new level for allocating stack slots. */
3280 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3281 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3282 expand_expr are made. After we end the region, we know that all
3283 space for all temporaries that were created by TARGET_EXPRs will be
3284 destroyed and their space freed for reuse. */
3287 expand_start_target_temps ()
3289 /* This is so that even if the result is preserved, the space
3290 allocated will be freed, as we know that it is no longer in use. */
3293 /* Start a new binding layer that will keep track of all cleanup
3294 actions to be performed. */
3295 expand_start_bindings (2);
3297 target_temp_slot_level = temp_slot_level;
3301 expand_end_target_temps ()
3303 expand_end_bindings (NULL_TREE, 0, 0);
3305 /* This is so that even if the result is preserved, the space
3306 allocated will be freed, as we know that it is no longer in use. */
3310 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3311 in question represents the outermost pair of curly braces (i.e. the "body
3312 block") of a function or method.
3314 For any BLOCK node representing a "body block" of a function or method, the
3315 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3316 represents the outermost (function) scope for the function or method (i.e.
3317 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3318 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3321 is_body_block (stmt)
3324 if (TREE_CODE (stmt) == BLOCK)
3326 tree parent = BLOCK_SUPERCONTEXT (stmt);
3328 if (parent && TREE_CODE (parent) == BLOCK)
3330 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3332 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3340 /* Mark top block of block_stack as an implicit binding for an
3341 exception region. This is used to prevent infinite recursion when
3342 ending a binding with expand_end_bindings. It is only ever called
3343 by expand_eh_region_start, as that it the only way to create a
3344 block stack for a exception region. */
3347 mark_block_as_eh_region ()
3349 block_stack->data.block.exception_region = 1;
3350 if (block_stack->next
3351 && block_stack->next->data.block.conditional_code)
3353 block_stack->data.block.conditional_code
3354 = block_stack->next->data.block.conditional_code;
3355 block_stack->data.block.last_unconditional_cleanup
3356 = block_stack->next->data.block.last_unconditional_cleanup;
3357 block_stack->data.block.cleanup_ptr
3358 = block_stack->next->data.block.cleanup_ptr;
3362 /* True if we are currently emitting insns in an area of output code
3363 that is controlled by a conditional expression. This is used by
3364 the cleanup handling code to generate conditional cleanup actions. */
3367 conditional_context ()
3369 return block_stack && block_stack->data.block.conditional_code;
3372 /* Mark top block of block_stack as not for an implicit binding for an
3373 exception region. This is only ever done by expand_eh_region_end
3374 to let expand_end_bindings know that it is being called explicitly
3375 to end the binding layer for just the binding layer associated with
3376 the exception region, otherwise expand_end_bindings would try and
3377 end all implicit binding layers for exceptions regions, and then
3378 one normal binding layer. */
3381 mark_block_as_not_eh_region ()
3383 block_stack->data.block.exception_region = 0;
3386 /* True if the top block of block_stack was marked as for an exception
3387 region by mark_block_as_eh_region. */
3392 return cfun && block_stack && block_stack->data.block.exception_region;
3395 /* Emit a handler label for a nonlocal goto handler.
3396 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3399 expand_nl_handler_label (slot, before_insn)
3400 rtx slot, before_insn;
3403 rtx handler_label = gen_label_rtx ();
3405 /* Don't let jump_optimize delete the handler. */
3406 LABEL_PRESERVE_P (handler_label) = 1;
3409 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3410 insns = get_insns ();
3412 emit_insns_before (insns, before_insn);
3414 emit_label (handler_label);
3416 return handler_label;
3419 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3422 expand_nl_goto_receiver ()
3424 #ifdef HAVE_nonlocal_goto
3425 if (! HAVE_nonlocal_goto)
3427 /* First adjust our frame pointer to its actual value. It was
3428 previously set to the start of the virtual area corresponding to
3429 the stacked variables when we branched here and now needs to be
3430 adjusted to the actual hardware fp value.
3432 Assignments are to virtual registers are converted by
3433 instantiate_virtual_regs into the corresponding assignment
3434 to the underlying register (fp in this case) that makes
3435 the original assignment true.
3436 So the following insn will actually be
3437 decrementing fp by STARTING_FRAME_OFFSET. */
3438 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3440 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3441 if (fixed_regs[ARG_POINTER_REGNUM])
3443 #ifdef ELIMINABLE_REGS
3444 /* If the argument pointer can be eliminated in favor of the
3445 frame pointer, we don't need to restore it. We assume here
3446 that if such an elimination is present, it can always be used.
3447 This is the case on all known machines; if we don't make this
3448 assumption, we do unnecessary saving on many machines. */
3449 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3452 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3453 if (elim_regs[i].from == ARG_POINTER_REGNUM
3454 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3457 if (i == sizeof elim_regs / sizeof elim_regs [0])
3460 /* Now restore our arg pointer from the address at which it
3461 was saved in our stack frame.
3462 If there hasn't be space allocated for it yet, make
3464 if (arg_pointer_save_area == 0)
3465 arg_pointer_save_area
3466 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3467 emit_move_insn (virtual_incoming_args_rtx,
3468 /* We need a pseudo here, or else
3469 instantiate_virtual_regs_1 complains. */
3470 copy_to_reg (arg_pointer_save_area));
3475 #ifdef HAVE_nonlocal_goto_receiver
3476 if (HAVE_nonlocal_goto_receiver)
3477 emit_insn (gen_nonlocal_goto_receiver ());
3481 /* Make handlers for nonlocal gotos taking place in the function calls in
3485 expand_nl_goto_receivers (thisblock)
3486 struct nesting *thisblock;
3489 rtx afterward = gen_label_rtx ();
3494 /* Record the handler address in the stack slot for that purpose,
3495 during this block, saving and restoring the outer value. */
3496 if (thisblock->next != 0)
3497 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3499 rtx save_receiver = gen_reg_rtx (Pmode);
3500 emit_move_insn (XEXP (slot, 0), save_receiver);
3503 emit_move_insn (save_receiver, XEXP (slot, 0));
3504 insns = get_insns ();
3506 emit_insns_before (insns, thisblock->data.block.first_insn);
3509 /* Jump around the handlers; they run only when specially invoked. */
3510 emit_jump (afterward);
3512 /* Make a separate handler for each label. */
3513 link = nonlocal_labels;
3514 slot = nonlocal_goto_handler_slots;
3515 label_list = NULL_RTX;
3516 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3517 /* Skip any labels we shouldn't be able to jump to from here,
3518 we generate one special handler for all of them below which just calls
3520 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3523 lab = expand_nl_handler_label (XEXP (slot, 0),
3524 thisblock->data.block.first_insn);
3525 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3527 expand_nl_goto_receiver ();
3529 /* Jump to the "real" nonlocal label. */
3530 expand_goto (TREE_VALUE (link));
3533 /* A second pass over all nonlocal labels; this time we handle those
3534 we should not be able to jump to at this point. */
3535 link = nonlocal_labels;
3536 slot = nonlocal_goto_handler_slots;
3538 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3539 if (DECL_TOO_LATE (TREE_VALUE (link)))
3542 lab = expand_nl_handler_label (XEXP (slot, 0),
3543 thisblock->data.block.first_insn);
3544 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3550 expand_nl_goto_receiver ();
3551 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3556 nonlocal_goto_handler_labels = label_list;
3557 emit_label (afterward);
3560 /* Warn about any unused VARS (which may contain nodes other than
3561 VAR_DECLs, but such nodes are ignored). The nodes are connected
3562 via the TREE_CHAIN field. */
3565 warn_about_unused_variables (vars)
3571 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3572 if (TREE_CODE (decl) == VAR_DECL
3573 && ! TREE_USED (decl)
3574 && ! DECL_IN_SYSTEM_HEADER (decl)
3575 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3576 warning_with_decl (decl, "unused variable `%s'");
3579 /* Generate RTL code to terminate a binding contour.
3581 VARS is the chain of VAR_DECL nodes for the variables bound in this
3582 contour. There may actually be other nodes in this chain, but any
3583 nodes other than VAR_DECLS are ignored.
3585 MARK_ENDS is nonzero if we should put a note at the beginning
3586 and end of this binding contour.
3588 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3589 (That is true automatically if the contour has a saved stack level.) */
3592 expand_end_bindings (vars, mark_ends, dont_jump_in)
3597 register struct nesting *thisblock;
3599 while (block_stack->data.block.exception_region)
3601 /* Because we don't need or want a new temporary level and
3602 because we didn't create one in expand_eh_region_start,
3603 create a fake one now to avoid removing one in
3604 expand_end_bindings. */
3607 block_stack->data.block.exception_region = 0;
3609 expand_end_bindings (NULL_TREE, 0, 0);
3612 /* Since expand_eh_region_start does an expand_start_bindings, we
3613 have to first end all the bindings that were created by
3614 expand_eh_region_start. */
3616 thisblock = block_stack;
3618 /* If any of the variables in this scope were not used, warn the
3620 warn_about_unused_variables (vars);
3622 if (thisblock->exit_label)
3624 do_pending_stack_adjust ();
3625 emit_label (thisblock->exit_label);
3628 /* If necessary, make handlers for nonlocal gotos taking
3629 place in the function calls in this block. */
3630 if (function_call_count != thisblock->data.block.n_function_calls
3632 /* Make handler for outermost block
3633 if there were any nonlocal gotos to this function. */
3634 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3635 /* Make handler for inner block if it has something
3636 special to do when you jump out of it. */
3637 : (thisblock->data.block.cleanups != 0
3638 || thisblock->data.block.stack_level != 0)))
3639 expand_nl_goto_receivers (thisblock);
3641 /* Don't allow jumping into a block that has a stack level.
3642 Cleanups are allowed, though. */
3644 || thisblock->data.block.stack_level != 0)
3646 struct label_chain *chain;
3648 /* Any labels in this block are no longer valid to go to.
3649 Mark them to cause an error message. */
3650 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3652 DECL_TOO_LATE (chain->label) = 1;
3653 /* If any goto without a fixup came to this label,
3654 that must be an error, because gotos without fixups
3655 come from outside all saved stack-levels. */
3656 if (TREE_ADDRESSABLE (chain->label))
3657 error_with_decl (chain->label,
3658 "label `%s' used before containing binding contour");
3662 /* Restore stack level in effect before the block
3663 (only if variable-size objects allocated). */
3664 /* Perform any cleanups associated with the block. */
3666 if (thisblock->data.block.stack_level != 0
3667 || thisblock->data.block.cleanups != 0)
3669 /* Only clean up here if this point can actually be reached. */
3670 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3672 /* Don't let cleanups affect ({...}) constructs. */
3673 int old_expr_stmts_for_value = expr_stmts_for_value;
3674 rtx old_last_expr_value = last_expr_value;
3675 tree old_last_expr_type = last_expr_type;
3676 expr_stmts_for_value = 0;
3678 /* Do the cleanups. */
3679 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3681 do_pending_stack_adjust ();
3683 expr_stmts_for_value = old_expr_stmts_for_value;
3684 last_expr_value = old_last_expr_value;
3685 last_expr_type = old_last_expr_type;
3687 /* Restore the stack level. */
3689 if (reachable && thisblock->data.block.stack_level != 0)
3691 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3692 thisblock->data.block.stack_level, NULL_RTX);
3693 if (nonlocal_goto_handler_slots != 0)
3694 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3698 /* Any gotos out of this block must also do these things.
3699 Also report any gotos with fixups that came to labels in this
3701 fixup_gotos (thisblock,
3702 thisblock->data.block.stack_level,
3703 thisblock->data.block.cleanups,
3704 thisblock->data.block.first_insn,
3708 /* Mark the beginning and end of the scope if requested.
3709 We do this now, after running cleanups on the variables
3710 just going out of scope, so they are in scope for their cleanups. */
3714 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3715 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3718 /* Get rid of the beginning-mark if we don't make an end-mark. */
3719 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3721 /* Restore the temporary level of TARGET_EXPRs. */
3722 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3724 /* Restore block_stack level for containing block. */
3726 stack_block_stack = thisblock->data.block.innermost_stack_block;
3727 POPSTACK (block_stack);
3729 /* Pop the stack slot nesting and free any slots at this level. */
3733 /* Generate RTL for the automatic variable declaration DECL.
3734 (Other kinds of declarations are simply ignored if seen here.) */
3740 struct nesting *thisblock;
3743 type = TREE_TYPE (decl);
3745 /* Only automatic variables need any expansion done.
3746 Static and external variables, and external functions,
3747 will be handled by `assemble_variable' (called from finish_decl).
3748 TYPE_DECL and CONST_DECL require nothing.
3749 PARM_DECLs are handled in `assign_parms'. */
3751 if (TREE_CODE (decl) != VAR_DECL)
3753 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3756 thisblock = block_stack;
3758 /* Create the RTL representation for the variable. */
3760 if (type == error_mark_node)
3761 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3762 else if (DECL_SIZE (decl) == 0)
3763 /* Variable with incomplete type. */
3765 if (DECL_INITIAL (decl) == 0)
3766 /* Error message was already done; now avoid a crash. */
3767 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3769 /* An initializer is going to decide the size of this array.
3770 Until we know the size, represent its address with a reg. */
3771 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3772 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3774 else if (DECL_MODE (decl) != BLKmode
3775 /* If -ffloat-store, don't put explicit float vars
3777 && !(flag_float_store
3778 && TREE_CODE (type) == REAL_TYPE)
3779 && ! TREE_THIS_VOLATILE (decl)
3780 && ! TREE_ADDRESSABLE (decl)
3781 && (DECL_REGISTER (decl) || optimize)
3782 /* if -fcheck-memory-usage, check all variables. */
3783 && ! current_function_check_memory_usage)
3785 /* Automatic variable that can go in a register. */
3786 int unsignedp = TREE_UNSIGNED (type);
3787 enum machine_mode reg_mode
3788 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3790 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3791 mark_user_reg (DECL_RTL (decl));
3793 if (POINTER_TYPE_P (type))
3794 mark_reg_pointer (DECL_RTL (decl),
3795 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3799 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3800 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3801 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3802 STACK_CHECK_MAX_VAR_SIZE)))
3804 /* Variable of fixed size that goes on the stack. */
3808 /* If we previously made RTL for this decl, it must be an array
3809 whose size was determined by the initializer.
3810 The old address was a register; set that register now
3811 to the proper address. */
3812 if (DECL_RTL (decl) != 0)
3814 if (GET_CODE (DECL_RTL (decl)) != MEM
3815 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3817 oldaddr = XEXP (DECL_RTL (decl), 0);
3820 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3821 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3822 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3824 /* Set alignment we actually gave this decl. */
3825 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3826 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3830 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3831 if (addr != oldaddr)
3832 emit_move_insn (oldaddr, addr);
3835 /* If this is a memory ref that contains aggregate components,
3836 mark it as such for cse and loop optimize. */
3837 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3838 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3840 /* If this is in memory because of -ffloat-store,
3841 set the volatile bit, to prevent optimizations from
3842 undoing the effects. */
3843 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3844 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3847 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3850 /* Dynamic-size object: must push space on the stack. */
3854 /* Record the stack pointer on entry to block, if have
3855 not already done so. */
3856 if (thisblock->data.block.stack_level == 0)
3858 do_pending_stack_adjust ();
3859 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3860 &thisblock->data.block.stack_level,
3861 thisblock->data.block.first_insn);
3862 stack_block_stack = thisblock;
3865 /* In function-at-a-time mode, variable_size doesn't expand this,
3867 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3868 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3869 const0_rtx, VOIDmode, 0);
3871 /* Compute the variable's size, in bytes. */
3872 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3875 /* Allocate space on the stack for the variable. Note that
3876 DECL_ALIGN says how the variable is to be aligned and we
3877 cannot use it to conclude anything about the alignment of
3879 address = allocate_dynamic_stack_space (size, NULL_RTX,
3880 TYPE_ALIGN (TREE_TYPE (decl)));
3882 /* Reference the variable indirect through that rtx. */
3883 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3885 /* If this is a memory ref that contains aggregate components,
3886 mark it as such for cse and loop optimize. */
3887 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3888 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3890 /* Indicate the alignment we actually gave this variable. */
3891 #ifdef STACK_BOUNDARY
3892 DECL_ALIGN (decl) = STACK_BOUNDARY;
3894 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3898 if (TREE_THIS_VOLATILE (decl))
3899 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3901 if (TREE_READONLY (decl))
3902 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3905 /* Emit code to perform the initialization of a declaration DECL. */
3908 expand_decl_init (decl)
3911 int was_used = TREE_USED (decl);
3913 /* If this is a CONST_DECL, we don't have to generate any code, but
3914 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3915 to be set while in the obstack containing the constant. If we don't
3916 do this, we can lose if we have functions nested three deep and the middle
3917 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3918 the innermost function is the first to expand that STRING_CST. */
3919 if (TREE_CODE (decl) == CONST_DECL)
3921 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3922 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3923 EXPAND_INITIALIZER);
3927 if (TREE_STATIC (decl))
3930 /* Compute and store the initial value now. */
3932 if (DECL_INITIAL (decl) == error_mark_node)
3934 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3936 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3937 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3938 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3942 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3944 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3945 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3949 /* Don't let the initialization count as "using" the variable. */
3950 TREE_USED (decl) = was_used;
3952 /* Free any temporaries we made while initializing the decl. */
3953 preserve_temp_slots (NULL_RTX);
3957 /* CLEANUP is an expression to be executed at exit from this binding contour;
3958 for example, in C++, it might call the destructor for this variable.
3960 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3961 CLEANUP multiple times, and have the correct semantics. This
3962 happens in exception handling, for gotos, returns, breaks that
3963 leave the current scope.
3965 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3966 that is not associated with any particular variable. */
3969 expand_decl_cleanup (decl, cleanup)
3972 struct nesting *thisblock;
3974 /* Error if we are not in any block. */
3975 if (cfun == 0 || block_stack == 0)
3978 thisblock = block_stack;
3980 /* Record the cleanup if there is one. */
3986 tree *cleanups = &thisblock->data.block.cleanups;
3987 int cond_context = conditional_context ();
3991 rtx flag = gen_reg_rtx (word_mode);
3996 emit_move_insn (flag, const0_rtx);
3997 set_flag_0 = get_insns ();
4000 thisblock->data.block.last_unconditional_cleanup
4001 = emit_insns_after (set_flag_0,
4002 thisblock->data.block.last_unconditional_cleanup);
4004 emit_move_insn (flag, const1_rtx);
4006 /* All cleanups must be on the function_obstack. */
4007 push_obstacks_nochange ();
4008 resume_temporary_allocation ();
4010 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4011 DECL_RTL (cond) = flag;
4013 /* Conditionalize the cleanup. */
4014 cleanup = build (COND_EXPR, void_type_node,
4015 truthvalue_conversion (cond),
4016 cleanup, integer_zero_node);
4017 cleanup = fold (cleanup);
4021 cleanups = thisblock->data.block.cleanup_ptr;
4024 /* All cleanups must be on the function_obstack. */
4025 push_obstacks_nochange ();
4026 resume_temporary_allocation ();
4027 cleanup = unsave_expr (cleanup);
4030 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4033 /* If this block has a cleanup, it belongs in stack_block_stack. */
4034 stack_block_stack = thisblock;
4041 /* If this was optimized so that there is no exception region for the
4042 cleanup, then mark the TREE_LIST node, so that we can later tell
4043 if we need to call expand_eh_region_end. */
4044 if (! using_eh_for_cleanups_p
4045 || expand_eh_region_start_tree (decl, cleanup))
4046 TREE_ADDRESSABLE (t) = 1;
4047 /* If that started a new EH region, we're in a new block. */
4048 thisblock = block_stack;
4055 thisblock->data.block.last_unconditional_cleanup
4056 = emit_insns_after (seq,
4057 thisblock->data.block.last_unconditional_cleanup);
4061 thisblock->data.block.last_unconditional_cleanup
4063 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4069 /* Like expand_decl_cleanup, but suppress generating an exception handler
4070 to perform the cleanup. */
4074 expand_decl_cleanup_no_eh (decl, cleanup)
4077 int save_eh = using_eh_for_cleanups_p;
4080 using_eh_for_cleanups_p = 0;
4081 result = expand_decl_cleanup (decl, cleanup);
4082 using_eh_for_cleanups_p = save_eh;
4088 /* Arrange for the top element of the dynamic cleanup chain to be
4089 popped if we exit the current binding contour. DECL is the
4090 associated declaration, if any, otherwise NULL_TREE. If the
4091 current contour is left via an exception, then __sjthrow will pop
4092 the top element off the dynamic cleanup chain. The code that
4093 avoids doing the action we push into the cleanup chain in the
4094 exceptional case is contained in expand_cleanups.
4096 This routine is only used by expand_eh_region_start, and that is
4097 the only way in which an exception region should be started. This
4098 routine is only used when using the setjmp/longjmp codegen method
4099 for exception handling. */
4102 expand_dcc_cleanup (decl)
4105 struct nesting *thisblock;
4108 /* Error if we are not in any block. */
4109 if (cfun == 0 || block_stack == 0)
4111 thisblock = block_stack;
4113 /* Record the cleanup for the dynamic handler chain. */
4115 /* All cleanups must be on the function_obstack. */
4116 push_obstacks_nochange ();
4117 resume_temporary_allocation ();
4118 cleanup = make_node (POPDCC_EXPR);
4121 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4122 thisblock->data.block.cleanups
4123 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4125 /* If this block has a cleanup, it belongs in stack_block_stack. */
4126 stack_block_stack = thisblock;
4130 /* Arrange for the top element of the dynamic handler chain to be
4131 popped if we exit the current binding contour. DECL is the
4132 associated declaration, if any, otherwise NULL_TREE. If the current
4133 contour is left via an exception, then __sjthrow will pop the top
4134 element off the dynamic handler chain. The code that avoids doing
4135 the action we push into the handler chain in the exceptional case
4136 is contained in expand_cleanups.
4138 This routine is only used by expand_eh_region_start, and that is
4139 the only way in which an exception region should be started. This
4140 routine is only used when using the setjmp/longjmp codegen method
4141 for exception handling. */
4144 expand_dhc_cleanup (decl)
4147 struct nesting *thisblock;
4150 /* Error if we are not in any block. */
4151 if (cfun == 0 || block_stack == 0)
4153 thisblock = block_stack;
4155 /* Record the cleanup for the dynamic handler chain. */
4157 /* All cleanups must be on the function_obstack. */
4158 push_obstacks_nochange ();
4159 resume_temporary_allocation ();
4160 cleanup = make_node (POPDHC_EXPR);
4163 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4164 thisblock->data.block.cleanups
4165 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4167 /* If this block has a cleanup, it belongs in stack_block_stack. */
4168 stack_block_stack = thisblock;
4172 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4173 DECL_ELTS is the list of elements that belong to DECL's type.
4174 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4177 expand_anon_union_decl (decl, cleanup, decl_elts)
4178 tree decl, cleanup, decl_elts;
4180 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4184 /* If any of the elements are addressable, so is the entire union. */
4185 for (t = decl_elts; t; t = TREE_CHAIN (t))
4186 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4188 TREE_ADDRESSABLE (decl) = 1;
4193 expand_decl_cleanup (decl, cleanup);
4194 x = DECL_RTL (decl);
4196 /* Go through the elements, assigning RTL to each. */
4197 for (t = decl_elts; t; t = TREE_CHAIN (t))
4199 tree decl_elt = TREE_VALUE (t);
4200 tree cleanup_elt = TREE_PURPOSE (t);
4201 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4203 /* Propagate the union's alignment to the elements. */
4204 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4206 /* If the element has BLKmode and the union doesn't, the union is
4207 aligned such that the element doesn't need to have BLKmode, so
4208 change the element's mode to the appropriate one for its size. */
4209 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4210 DECL_MODE (decl_elt) = mode
4211 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4213 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4214 instead create a new MEM rtx with the proper mode. */
4215 if (GET_CODE (x) == MEM)
4217 if (mode == GET_MODE (x))
4218 DECL_RTL (decl_elt) = x;
4221 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4222 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4223 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4226 else if (GET_CODE (x) == REG)
4228 if (mode == GET_MODE (x))
4229 DECL_RTL (decl_elt) = x;
4231 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4236 /* Record the cleanup if there is one. */
4239 thisblock->data.block.cleanups
4240 = temp_tree_cons (decl_elt, cleanup_elt,
4241 thisblock->data.block.cleanups);
4245 /* Expand a list of cleanups LIST.
4246 Elements may be expressions or may be nested lists.
4248 If DONT_DO is nonnull, then any list-element
4249 whose TREE_PURPOSE matches DONT_DO is omitted.
4250 This is sometimes used to avoid a cleanup associated with
4251 a value that is being returned out of the scope.
4253 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4254 goto and handle protection regions specially in that case.
4256 If REACHABLE, we emit code, otherwise just inform the exception handling
4257 code about this finalization. */
4260 expand_cleanups (list, dont_do, in_fixup, reachable)
4267 for (tail = list; tail; tail = TREE_CHAIN (tail))
4268 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4270 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4271 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4276 tree cleanup = TREE_VALUE (tail);
4278 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4279 if (TREE_CODE (cleanup) != POPDHC_EXPR
4280 && TREE_CODE (cleanup) != POPDCC_EXPR
4281 /* See expand_eh_region_start_tree for this case. */
4282 && ! TREE_ADDRESSABLE (tail))
4284 cleanup = protect_with_terminate (cleanup);
4285 expand_eh_region_end (cleanup);
4291 /* Cleanups may be run multiple times. For example,
4292 when exiting a binding contour, we expand the
4293 cleanups associated with that contour. When a goto
4294 within that binding contour has a target outside that
4295 contour, it will expand all cleanups from its scope to
4296 the target. Though the cleanups are expanded multiple
4297 times, the control paths are non-overlapping so the
4298 cleanups will not be executed twice. */
4300 /* We may need to protect fixups with rethrow regions. */
4301 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4304 expand_fixup_region_start ();
4306 /* The cleanup might contain try-blocks, so we have to
4307 preserve our current queue. */
4309 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4312 expand_fixup_region_end (TREE_VALUE (tail));
4319 /* Mark when the context we are emitting RTL for as a conditional
4320 context, so that any cleanup actions we register with
4321 expand_decl_init will be properly conditionalized when those
4322 cleanup actions are later performed. Must be called before any
4323 expression (tree) is expanded that is within a conditional context. */
4326 start_cleanup_deferral ()
4328 /* block_stack can be NULL if we are inside the parameter list. It is
4329 OK to do nothing, because cleanups aren't possible here. */
4331 ++block_stack->data.block.conditional_code;
4334 /* Mark the end of a conditional region of code. Because cleanup
4335 deferrals may be nested, we may still be in a conditional region
4336 after we end the currently deferred cleanups, only after we end all
4337 deferred cleanups, are we back in unconditional code. */
4340 end_cleanup_deferral ()
4342 /* block_stack can be NULL if we are inside the parameter list. It is
4343 OK to do nothing, because cleanups aren't possible here. */
4345 --block_stack->data.block.conditional_code;
4348 /* Move all cleanups from the current block_stack
4349 to the containing block_stack, where they are assumed to
4350 have been created. If anything can cause a temporary to
4351 be created, but not expanded for more than one level of
4352 block_stacks, then this code will have to change. */
4357 struct nesting *block = block_stack;
4358 struct nesting *outer = block->next;
4360 outer->data.block.cleanups
4361 = chainon (block->data.block.cleanups,
4362 outer->data.block.cleanups);
4363 block->data.block.cleanups = 0;
4367 last_cleanup_this_contour ()
4369 if (block_stack == 0)
4372 return block_stack->data.block.cleanups;
4375 /* Return 1 if there are any pending cleanups at this point.
4376 If THIS_CONTOUR is nonzero, check the current contour as well.
4377 Otherwise, look only at the contours that enclose this one. */
4380 any_pending_cleanups (this_contour)
4383 struct nesting *block;
4385 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4388 if (this_contour && block_stack->data.block.cleanups != NULL)
4390 if (block_stack->data.block.cleanups == 0
4391 && block_stack->data.block.outer_cleanups == 0)
4394 for (block = block_stack->next; block; block = block->next)
4395 if (block->data.block.cleanups != 0)
4401 /* Enter a case (Pascal) or switch (C) statement.
4402 Push a block onto case_stack and nesting_stack
4403 to accumulate the case-labels that are seen
4404 and to record the labels generated for the statement.
4406 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4407 Otherwise, this construct is transparent for `exit_something'.
4409 EXPR is the index-expression to be dispatched on.
4410 TYPE is its nominal type. We could simply convert EXPR to this type,
4411 but instead we take short cuts. */
4414 expand_start_case (exit_flag, expr, type, printname)
4418 const char *printname;
4420 register struct nesting *thiscase = ALLOC_NESTING ();
4422 /* Make an entry on case_stack for the case we are entering. */
4424 thiscase->next = case_stack;
4425 thiscase->all = nesting_stack;
4426 thiscase->depth = ++nesting_depth;
4427 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4428 thiscase->data.case_stmt.case_list = 0;
4429 thiscase->data.case_stmt.index_expr = expr;
4430 thiscase->data.case_stmt.nominal_type = type;
4431 thiscase->data.case_stmt.default_label = 0;
4432 thiscase->data.case_stmt.num_ranges = 0;
4433 thiscase->data.case_stmt.printname = printname;
4434 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4435 case_stack = thiscase;
4436 nesting_stack = thiscase;
4438 do_pending_stack_adjust ();
4440 /* Make sure case_stmt.start points to something that won't
4441 need any transformation before expand_end_case. */
4442 if (GET_CODE (get_last_insn ()) != NOTE)
4443 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4445 thiscase->data.case_stmt.start = get_last_insn ();
4447 start_cleanup_deferral ();
4451 /* Start a "dummy case statement" within which case labels are invalid
4452 and are not connected to any larger real case statement.
4453 This can be used if you don't want to let a case statement jump
4454 into the middle of certain kinds of constructs. */
4457 expand_start_case_dummy ()
4459 register struct nesting *thiscase = ALLOC_NESTING ();
4461 /* Make an entry on case_stack for the dummy. */
4463 thiscase->next = case_stack;
4464 thiscase->all = nesting_stack;
4465 thiscase->depth = ++nesting_depth;
4466 thiscase->exit_label = 0;
4467 thiscase->data.case_stmt.case_list = 0;
4468 thiscase->data.case_stmt.start = 0;
4469 thiscase->data.case_stmt.nominal_type = 0;
4470 thiscase->data.case_stmt.default_label = 0;
4471 thiscase->data.case_stmt.num_ranges = 0;
4472 case_stack = thiscase;
4473 nesting_stack = thiscase;
4474 start_cleanup_deferral ();
4477 /* End a dummy case statement. */
4480 expand_end_case_dummy ()
4482 end_cleanup_deferral ();
4483 POPSTACK (case_stack);
4486 /* Return the data type of the index-expression
4487 of the innermost case statement, or null if none. */
4490 case_index_expr_type ()
4493 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4500 /* If this is the first label, warn if any insns have been emitted. */
4501 if (case_stack->data.case_stmt.line_number_status >= 0)
4505 restore_line_number_status
4506 (case_stack->data.case_stmt.line_number_status);
4507 case_stack->data.case_stmt.line_number_status = -1;
4509 for (insn = case_stack->data.case_stmt.start;
4511 insn = NEXT_INSN (insn))
4513 if (GET_CODE (insn) == CODE_LABEL)
4515 if (GET_CODE (insn) != NOTE
4516 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4519 insn = PREV_INSN (insn);
4520 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4522 /* If insn is zero, then there must have been a syntax error. */
4524 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4525 NOTE_LINE_NUMBER(insn),
4526 "unreachable code at beginning of %s",
4527 case_stack->data.case_stmt.printname);
4534 /* Accumulate one case or default label inside a case or switch statement.
4535 VALUE is the value of the case (a null pointer, for a default label).
4536 The function CONVERTER, when applied to arguments T and V,
4537 converts the value V to the type T.
4539 If not currently inside a case or switch statement, return 1 and do
4540 nothing. The caller will print a language-specific error message.
4541 If VALUE is a duplicate or overlaps, return 2 and do nothing
4542 except store the (first) duplicate node in *DUPLICATE.
4543 If VALUE is out of range, return 3 and do nothing.
4544 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4545 Return 0 on success.
4547 Extended to handle range statements. */
4550 pushcase (value, converter, label, duplicate)
4551 register tree value;
4552 tree (*converter) PARAMS ((tree, tree));
4553 register tree label;
4559 /* Fail if not inside a real case statement. */
4560 if (! (case_stack && case_stack->data.case_stmt.start))
4563 if (stack_block_stack
4564 && stack_block_stack->depth > case_stack->depth)
4567 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4568 nominal_type = case_stack->data.case_stmt.nominal_type;
4570 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4571 if (index_type == error_mark_node)
4574 /* Convert VALUE to the type in which the comparisons are nominally done. */
4576 value = (*converter) (nominal_type, value);
4580 /* Fail if this value is out of range for the actual type of the index
4581 (which may be narrower than NOMINAL_TYPE). */
4583 && (TREE_CONSTANT_OVERFLOW (value)
4584 || ! int_fits_type_p (value, index_type)))
4587 /* Fail if this is a duplicate or overlaps another entry. */
4590 if (case_stack->data.case_stmt.default_label != 0)
4592 *duplicate = case_stack->data.case_stmt.default_label;
4595 case_stack->data.case_stmt.default_label = label;
4598 return add_case_node (value, value, label, duplicate);
4600 expand_label (label);
4604 /* Like pushcase but this case applies to all values between VALUE1 and
4605 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4606 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4607 starts at VALUE1 and ends at the highest value of the index type.
4608 If both are NULL, this case applies to all values.
4610 The return value is the same as that of pushcase but there is one
4611 additional error code: 4 means the specified range was empty. */
4614 pushcase_range (value1, value2, converter, label, duplicate)
4615 register tree value1, value2;
4616 tree (*converter) PARAMS ((tree, tree));
4617 register tree label;
4623 /* Fail if not inside a real case statement. */
4624 if (! (case_stack && case_stack->data.case_stmt.start))
4627 if (stack_block_stack
4628 && stack_block_stack->depth > case_stack->depth)
4631 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4632 nominal_type = case_stack->data.case_stmt.nominal_type;
4634 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4635 if (index_type == error_mark_node)
4640 /* Convert VALUEs to type in which the comparisons are nominally done
4641 and replace any unspecified value with the corresponding bound. */
4643 value1 = TYPE_MIN_VALUE (index_type);
4645 value2 = TYPE_MAX_VALUE (index_type);
4647 /* Fail if the range is empty. Do this before any conversion since
4648 we want to allow out-of-range empty ranges. */
4649 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4652 /* If the max was unbounded, use the max of the nominal_type we are
4653 converting to. Do this after the < check above to suppress false
4656 value2 = TYPE_MAX_VALUE (nominal_type);
4658 value1 = (*converter) (nominal_type, value1);
4659 value2 = (*converter) (nominal_type, value2);
4661 /* Fail if these values are out of range. */
4662 if (TREE_CONSTANT_OVERFLOW (value1)
4663 || ! int_fits_type_p (value1, index_type))
4666 if (TREE_CONSTANT_OVERFLOW (value2)
4667 || ! int_fits_type_p (value2, index_type))
4670 return add_case_node (value1, value2, label, duplicate);
4673 /* Do the actual insertion of a case label for pushcase and pushcase_range
4674 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4675 slowdown for large switch statements. */
4678 add_case_node (low, high, label, duplicate)
4683 struct case_node *p, **q, *r;
4685 q = &case_stack->data.case_stmt.case_list;
4692 /* Keep going past elements distinctly greater than HIGH. */
4693 if (tree_int_cst_lt (high, p->low))
4696 /* or distinctly less than LOW. */
4697 else if (tree_int_cst_lt (p->high, low))
4702 /* We have an overlap; this is an error. */
4703 *duplicate = p->code_label;
4708 /* Add this label to the chain, and succeed.
4709 Copy LOW, HIGH so they are on temporary rather than momentary
4710 obstack and will thus survive till the end of the case statement. */
4712 r = (struct case_node *) oballoc (sizeof (struct case_node));
4713 r->low = copy_node (low);
4715 /* If the bounds are equal, turn this into the one-value case. */
4717 if (tree_int_cst_equal (low, high))
4721 r->high = copy_node (high);
4722 case_stack->data.case_stmt.num_ranges++;
4725 r->code_label = label;
4726 expand_label (label);
4736 struct case_node *s;
4742 if (! (b = p->balance))
4743 /* Growth propagation from left side. */
4750 if ((p->left = s = r->right))
4759 if ((r->parent = s))
4767 case_stack->data.case_stmt.case_list = r;
4770 /* r->balance == +1 */
4775 struct case_node *t = r->right;
4777 if ((p->left = s = t->right))
4781 if ((r->right = s = t->left))
4795 if ((t->parent = s))
4803 case_stack->data.case_stmt.case_list = t;
4810 /* p->balance == +1; growth of left side balances the node. */
4820 if (! (b = p->balance))
4821 /* Growth propagation from right side. */
4829 if ((p->right = s = r->left))
4837 if ((r->parent = s))
4846 case_stack->data.case_stmt.case_list = r;
4850 /* r->balance == -1 */
4854 struct case_node *t = r->left;
4856 if ((p->right = s = t->left))
4861 if ((r->left = s = t->right))
4875 if ((t->parent = s))
4884 case_stack->data.case_stmt.case_list = t;
4890 /* p->balance == -1; growth of right side balances the node. */
4904 /* Returns the number of possible values of TYPE.
4905 Returns -1 if the number is unknown, variable, or if the number does not
4906 fit in a HOST_WIDE_INT.
4907 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4908 do not increase monotonically (there may be duplicates);
4909 to 1 if the values increase monotonically, but not always by 1;
4910 otherwise sets it to 0. */
4913 all_cases_count (type, spareness)
4918 HOST_WIDE_INT count, minval, lastval;
4922 switch (TREE_CODE (type))
4929 count = 1 << BITS_PER_UNIT;
4934 if (TYPE_MAX_VALUE (type) != 0
4935 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4936 TYPE_MIN_VALUE (type))))
4937 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4938 convert (type, integer_zero_node))))
4939 && host_integerp (t, 1))
4940 count = tree_low_cst (t, 1);
4946 /* Don't waste time with enumeral types with huge values. */
4947 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4948 || TYPE_MAX_VALUE (type) == 0
4949 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4952 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4955 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4957 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4959 if (*spareness == 2 || thisval < lastval)
4961 else if (thisval != minval + count)
4971 #define BITARRAY_TEST(ARRAY, INDEX) \
4972 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4973 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4974 #define BITARRAY_SET(ARRAY, INDEX) \
4975 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4976 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4978 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4979 with the case values we have seen, assuming the case expression
4981 SPARSENESS is as determined by all_cases_count.
4983 The time needed is proportional to COUNT, unless
4984 SPARSENESS is 2, in which case quadratic time is needed. */
4987 mark_seen_cases (type, cases_seen, count, sparseness)
4989 unsigned char *cases_seen;
4990 HOST_WIDE_INT count;
4993 tree next_node_to_try = NULL_TREE;
4994 HOST_WIDE_INT next_node_offset = 0;
4996 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4997 tree val = make_node (INTEGER_CST);
4999 TREE_TYPE (val) = type;
5002 else if (sparseness == 2)
5005 unsigned HOST_WIDE_INT xlo;
5007 /* This less efficient loop is only needed to handle
5008 duplicate case values (multiple enum constants
5009 with the same value). */
5010 TREE_TYPE (val) = TREE_TYPE (root->low);
5011 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5012 t = TREE_CHAIN (t), xlo++)
5014 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5015 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5019 /* Keep going past elements distinctly greater than VAL. */
5020 if (tree_int_cst_lt (val, n->low))
5023 /* or distinctly less than VAL. */
5024 else if (tree_int_cst_lt (n->high, val))
5029 /* We have found a matching range. */
5030 BITARRAY_SET (cases_seen, xlo);
5040 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5042 for (n = root; n; n = n->right)
5044 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5045 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5046 while ( ! tree_int_cst_lt (n->high, val))
5048 /* Calculate (into xlo) the "offset" of the integer (val).
5049 The element with lowest value has offset 0, the next smallest
5050 element has offset 1, etc. */
5052 unsigned HOST_WIDE_INT xlo;
5056 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5058 /* The TYPE_VALUES will be in increasing order, so
5059 starting searching where we last ended. */
5060 t = next_node_to_try;
5061 xlo = next_node_offset;
5067 t = TYPE_VALUES (type);
5070 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5072 next_node_to_try = TREE_CHAIN (t);
5073 next_node_offset = xlo + 1;
5078 if (t == next_node_to_try)
5087 t = TYPE_MIN_VALUE (type);
5089 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5093 add_double (xlo, xhi,
5094 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5098 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5099 BITARRAY_SET (cases_seen, xlo);
5101 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5103 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5109 /* Called when the index of a switch statement is an enumerated type
5110 and there is no default label.
5112 Checks that all enumeration literals are covered by the case
5113 expressions of a switch. Also, warn if there are any extra
5114 switch cases that are *not* elements of the enumerated type.
5116 If all enumeration literals were covered by the case expressions,
5117 turn one of the expressions into the default expression since it should
5118 not be possible to fall through such a switch. */
5121 check_for_full_enumeration_handling (type)
5124 register struct case_node *n;
5125 register tree chain;
5126 #if 0 /* variable used by 'if 0'ed code below. */
5127 register struct case_node **l;
5131 /* True iff the selector type is a numbered set mode. */
5134 /* The number of possible selector values. */
5137 /* For each possible selector value. a one iff it has been matched
5138 by a case value alternative. */
5139 unsigned char *cases_seen;
5141 /* The allocated size of cases_seen, in chars. */
5142 HOST_WIDE_INT bytes_needed;
5147 size = all_cases_count (type, &sparseness);
5148 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5150 if (size > 0 && size < 600000
5151 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5152 this optimization if we don't have enough memory rather than
5153 aborting, as xmalloc would do. */
5154 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5157 tree v = TYPE_VALUES (type);
5159 /* The time complexity of this code is normally O(N), where
5160 N being the number of members in the enumerated type.
5161 However, if type is a ENUMERAL_TYPE whose values do not
5162 increase monotonically, O(N*log(N)) time may be needed. */
5164 mark_seen_cases (type, cases_seen, size, sparseness);
5166 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5167 if (BITARRAY_TEST(cases_seen, i) == 0)
5168 warning ("enumeration value `%s' not handled in switch",
5169 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5174 /* Now we go the other way around; we warn if there are case
5175 expressions that don't correspond to enumerators. This can
5176 occur since C and C++ don't enforce type-checking of
5177 assignments to enumeration variables. */
5179 if (case_stack->data.case_stmt.case_list
5180 && case_stack->data.case_stmt.case_list->left)
5181 case_stack->data.case_stmt.case_list
5182 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5184 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5186 for (chain = TYPE_VALUES (type);
5187 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5188 chain = TREE_CHAIN (chain))
5193 if (TYPE_NAME (type) == 0)
5194 warning ("case value `%ld' not in enumerated type",
5195 (long) TREE_INT_CST_LOW (n->low));
5197 warning ("case value `%ld' not in enumerated type `%s'",
5198 (long) TREE_INT_CST_LOW (n->low),
5199 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5202 : DECL_NAME (TYPE_NAME (type))));
5204 if (!tree_int_cst_equal (n->low, n->high))
5206 for (chain = TYPE_VALUES (type);
5207 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5208 chain = TREE_CHAIN (chain))
5213 if (TYPE_NAME (type) == 0)
5214 warning ("case value `%ld' not in enumerated type",
5215 (long) TREE_INT_CST_LOW (n->high));
5217 warning ("case value `%ld' not in enumerated type `%s'",
5218 (long) TREE_INT_CST_LOW (n->high),
5219 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5222 : DECL_NAME (TYPE_NAME (type))));
5228 /* ??? This optimization is disabled because it causes valid programs to
5229 fail. ANSI C does not guarantee that an expression with enum type
5230 will have a value that is the same as one of the enumeration literals. */
5232 /* If all values were found as case labels, make one of them the default
5233 label. Thus, this switch will never fall through. We arbitrarily pick
5234 the last one to make the default since this is likely the most
5235 efficient choice. */
5239 for (l = &case_stack->data.case_stmt.case_list;
5244 case_stack->data.case_stmt.default_label = (*l)->code_label;
5251 /* Terminate a case (Pascal) or switch (C) statement
5252 in which ORIG_INDEX is the expression to be tested.
5253 Generate the code to test it and jump to the right place. */
5256 expand_end_case (orig_index)
5259 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5260 rtx default_label = 0;
5261 register struct case_node *n;
5269 register struct nesting *thiscase = case_stack;
5270 tree index_expr, index_type;
5273 /* Don't crash due to previous errors. */
5274 if (thiscase == NULL)
5277 table_label = gen_label_rtx ();
5278 index_expr = thiscase->data.case_stmt.index_expr;
5279 index_type = TREE_TYPE (index_expr);
5280 unsignedp = TREE_UNSIGNED (index_type);
5282 do_pending_stack_adjust ();
5284 /* This might get an spurious warning in the presence of a syntax error;
5285 it could be fixed by moving the call to check_seenlabel after the
5286 check for error_mark_node, and copying the code of check_seenlabel that
5287 deals with case_stack->data.case_stmt.line_number_status /
5288 restore_line_number_status in front of the call to end_cleanup_deferral;
5289 However, this might miss some useful warnings in the presence of
5290 non-syntax errors. */
5293 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5294 if (index_type != error_mark_node)
5296 /* If switch expression was an enumerated type, check that all
5297 enumeration literals are covered by the cases.
5298 No sense trying this if there's a default case, however. */
5300 if (!thiscase->data.case_stmt.default_label
5301 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5302 && TREE_CODE (index_expr) != INTEGER_CST)
5303 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5305 /* If we don't have a default-label, create one here,
5306 after the body of the switch. */
5307 if (thiscase->data.case_stmt.default_label == 0)
5309 thiscase->data.case_stmt.default_label
5310 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5311 expand_label (thiscase->data.case_stmt.default_label);
5313 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5315 before_case = get_last_insn ();
5317 if (thiscase->data.case_stmt.case_list
5318 && thiscase->data.case_stmt.case_list->left)
5319 thiscase->data.case_stmt.case_list
5320 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5322 /* Simplify the case-list before we count it. */
5323 group_case_nodes (thiscase->data.case_stmt.case_list);
5325 /* Get upper and lower bounds of case values.
5326 Also convert all the case values to the index expr's data type. */
5329 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5331 /* Check low and high label values are integers. */
5332 if (TREE_CODE (n->low) != INTEGER_CST)
5334 if (TREE_CODE (n->high) != INTEGER_CST)
5337 n->low = convert (index_type, n->low);
5338 n->high = convert (index_type, n->high);
5340 /* Count the elements and track the largest and smallest
5341 of them (treating them as signed even if they are not). */
5349 if (INT_CST_LT (n->low, minval))
5351 if (INT_CST_LT (maxval, n->high))
5354 /* A range counts double, since it requires two compares. */
5355 if (! tree_int_cst_equal (n->low, n->high))
5359 orig_minval = minval;
5361 /* Compute span of values. */
5363 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5365 end_cleanup_deferral ();
5369 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5371 emit_jump (default_label);
5374 /* If range of values is much bigger than number of values,
5375 make a sequence of conditional branches instead of a dispatch.
5376 If the switch-index is a constant, do it this way
5377 because we can optimize it. */
5379 #ifndef CASE_VALUES_THRESHOLD
5381 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5383 /* If machine does not have a case insn that compares the
5384 bounds, this means extra overhead for dispatch tables
5385 which raises the threshold for using them. */
5386 #define CASE_VALUES_THRESHOLD 5
5387 #endif /* HAVE_casesi */
5388 #endif /* CASE_VALUES_THRESHOLD */
5390 else if (count < CASE_VALUES_THRESHOLD
5391 || compare_tree_int (range, 10 * count) > 0
5392 /* RANGE may be signed, and really large ranges will show up
5393 as negative numbers. */
5394 || compare_tree_int (range, 0) < 0
5395 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5398 || TREE_CODE (index_expr) == INTEGER_CST
5399 /* These will reduce to a constant. */
5400 || (TREE_CODE (index_expr) == CALL_EXPR
5401 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5402 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5403 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5404 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5405 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5406 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5408 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5410 /* If the index is a short or char that we do not have
5411 an insn to handle comparisons directly, convert it to
5412 a full integer now, rather than letting each comparison
5413 generate the conversion. */
5415 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5416 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5417 == CODE_FOR_nothing))
5419 enum machine_mode wider_mode;
5420 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5421 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5422 if (cmp_optab->handlers[(int) wider_mode].insn_code
5423 != CODE_FOR_nothing)
5425 index = convert_to_mode (wider_mode, index, unsignedp);
5431 do_pending_stack_adjust ();
5433 index = protect_from_queue (index, 0);
5434 if (GET_CODE (index) == MEM)
5435 index = copy_to_reg (index);
5436 if (GET_CODE (index) == CONST_INT
5437 || TREE_CODE (index_expr) == INTEGER_CST)
5439 /* Make a tree node with the proper constant value
5440 if we don't already have one. */
5441 if (TREE_CODE (index_expr) != INTEGER_CST)
5444 = build_int_2 (INTVAL (index),
5445 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5446 index_expr = convert (index_type, index_expr);
5449 /* For constant index expressions we need only
5450 issue a unconditional branch to the appropriate
5451 target code. The job of removing any unreachable
5452 code is left to the optimisation phase if the
5453 "-O" option is specified. */
5454 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5455 if (! tree_int_cst_lt (index_expr, n->low)
5456 && ! tree_int_cst_lt (n->high, index_expr))
5460 emit_jump (label_rtx (n->code_label));
5462 emit_jump (default_label);
5466 /* If the index expression is not constant we generate
5467 a binary decision tree to select the appropriate
5468 target code. This is done as follows:
5470 The list of cases is rearranged into a binary tree,
5471 nearly optimal assuming equal probability for each case.
5473 The tree is transformed into RTL, eliminating
5474 redundant test conditions at the same time.
5476 If program flow could reach the end of the
5477 decision tree an unconditional jump to the
5478 default code is emitted. */
5481 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5482 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5483 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5485 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5486 default_label, index_type);
5487 emit_jump_if_reachable (default_label);
5496 enum machine_mode index_mode = SImode;
5497 int index_bits = GET_MODE_BITSIZE (index_mode);
5499 enum machine_mode op_mode;
5501 /* Convert the index to SImode. */
5502 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5503 > GET_MODE_BITSIZE (index_mode))
5505 enum machine_mode omode = TYPE_MODE (index_type);
5506 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5508 /* We must handle the endpoints in the original mode. */
5509 index_expr = build (MINUS_EXPR, index_type,
5510 index_expr, minval);
5511 minval = integer_zero_node;
5512 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5513 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5514 omode, 1, 0, default_label);
5515 /* Now we can safely truncate. */
5516 index = convert_to_mode (index_mode, index, 0);
5520 if (TYPE_MODE (index_type) != index_mode)
5522 index_expr = convert (type_for_size (index_bits, 0),
5524 index_type = TREE_TYPE (index_expr);
5527 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5530 index = protect_from_queue (index, 0);
5531 do_pending_stack_adjust ();
5533 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5534 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5536 index = copy_to_mode_reg (op_mode, index);
5538 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5540 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5541 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5543 op1 = copy_to_mode_reg (op_mode, op1);
5545 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5547 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5548 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5550 op2 = copy_to_mode_reg (op_mode, op2);
5552 emit_jump_insn (gen_casesi (index, op1, op2,
5553 table_label, default_label));
5557 #ifdef HAVE_tablejump
5558 if (! win && HAVE_tablejump)
5560 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5561 fold (build (MINUS_EXPR, index_type,
5562 index_expr, minval)));
5563 index_type = TREE_TYPE (index_expr);
5564 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5566 index = protect_from_queue (index, 0);
5567 do_pending_stack_adjust ();
5569 do_tablejump (index, TYPE_MODE (index_type),
5570 expand_expr (range, NULL_RTX, VOIDmode, 0),
5571 table_label, default_label);
5578 /* Get table of labels to jump to, in order of case index. */
5580 ncases = TREE_INT_CST_LOW (range) + 1;
5581 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5582 bzero ((char *) labelvec, ncases * sizeof (rtx));
5584 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5586 register HOST_WIDE_INT i
5587 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5592 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5593 if (i + TREE_INT_CST_LOW (orig_minval)
5594 == TREE_INT_CST_LOW (n->high))
5600 /* Fill in the gaps with the default. */
5601 for (i = 0; i < ncases; i++)
5602 if (labelvec[i] == 0)
5603 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5605 /* Output the table */
5606 emit_label (table_label);
5608 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5609 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5610 gen_rtx_LABEL_REF (Pmode, table_label),
5611 gen_rtvec_v (ncases, labelvec),
5612 const0_rtx, const0_rtx));
5614 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5615 gen_rtvec_v (ncases, labelvec)));
5617 /* If the case insn drops through the table,
5618 after the table we must jump to the default-label.
5619 Otherwise record no drop-through after the table. */
5620 #ifdef CASE_DROPS_THROUGH
5621 emit_jump (default_label);
5627 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5628 reorder_insns (before_case, get_last_insn (),
5629 thiscase->data.case_stmt.start);
5632 end_cleanup_deferral ();
5634 if (thiscase->exit_label)
5635 emit_label (thiscase->exit_label);
5637 POPSTACK (case_stack);
5642 /* Convert the tree NODE into a list linked by the right field, with the left
5643 field zeroed. RIGHT is used for recursion; it is a list to be placed
5644 rightmost in the resulting list. */
5646 static struct case_node *
5647 case_tree2list (node, right)
5648 struct case_node *node, *right;
5650 struct case_node *left;
5653 right = case_tree2list (node->right, right);
5655 node->right = right;
5656 if ((left = node->left))
5659 return case_tree2list (left, node);
5665 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5668 do_jump_if_equal (op1, op2, label, unsignedp)
5669 rtx op1, op2, label;
5672 if (GET_CODE (op1) == CONST_INT
5673 && GET_CODE (op2) == CONST_INT)
5675 if (INTVAL (op1) == INTVAL (op2))
5680 enum machine_mode mode = GET_MODE (op1);
5681 if (mode == VOIDmode)
5682 mode = GET_MODE (op2);
5683 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5688 /* Not all case values are encountered equally. This function
5689 uses a heuristic to weight case labels, in cases where that
5690 looks like a reasonable thing to do.
5692 Right now, all we try to guess is text, and we establish the
5695 chars above space: 16
5704 If we find any cases in the switch that are not either -1 or in the range
5705 of valid ASCII characters, or are control characters other than those
5706 commonly used with "\", don't treat this switch scanning text.
5708 Return 1 if these nodes are suitable for cost estimation, otherwise
5712 estimate_case_costs (node)
5715 tree min_ascii = build_int_2 (-1, -1);
5716 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5720 /* If we haven't already made the cost table, make it now. Note that the
5721 lower bound of the table is -1, not zero. */
5723 if (cost_table == NULL)
5725 cost_table = cost_table_ + 1;
5727 for (i = 0; i < 128; i++)
5731 else if (ISPUNCT (i))
5733 else if (ISCNTRL (i))
5737 cost_table[' '] = 8;
5738 cost_table['\t'] = 4;
5739 cost_table['\0'] = 4;
5740 cost_table['\n'] = 2;
5741 cost_table['\f'] = 1;
5742 cost_table['\v'] = 1;
5743 cost_table['\b'] = 1;
5746 /* See if all the case expressions look like text. It is text if the
5747 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5748 as signed arithmetic since we don't want to ever access cost_table with a
5749 value less than -1. Also check that none of the constants in a range
5750 are strange control characters. */
5752 for (n = node; n; n = n->right)
5754 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5757 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5758 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5759 if (cost_table[i] < 0)
5763 /* All interesting values are within the range of interesting
5764 ASCII characters. */
5768 /* Scan an ordered list of case nodes
5769 combining those with consecutive values or ranges.
5771 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5774 group_case_nodes (head)
5777 case_node_ptr node = head;
5781 rtx lb = next_real_insn (label_rtx (node->code_label));
5783 case_node_ptr np = node;
5785 /* Try to group the successors of NODE with NODE. */
5786 while (((np = np->right) != 0)
5787 /* Do they jump to the same place? */
5788 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5789 || (lb != 0 && lb2 != 0
5790 && simplejump_p (lb)
5791 && simplejump_p (lb2)
5792 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5793 SET_SRC (PATTERN (lb2)))))
5794 /* Are their ranges consecutive? */
5795 && tree_int_cst_equal (np->low,
5796 fold (build (PLUS_EXPR,
5797 TREE_TYPE (node->high),
5800 /* An overflow is not consecutive. */
5801 && tree_int_cst_lt (node->high,
5802 fold (build (PLUS_EXPR,
5803 TREE_TYPE (node->high),
5805 integer_one_node))))
5807 node->high = np->high;
5809 /* NP is the first node after NODE which can't be grouped with it.
5810 Delete the nodes in between, and move on to that node. */
5816 /* Take an ordered list of case nodes
5817 and transform them into a near optimal binary tree,
5818 on the assumption that any target code selection value is as
5819 likely as any other.
5821 The transformation is performed by splitting the ordered
5822 list into two equal sections plus a pivot. The parts are
5823 then attached to the pivot as left and right branches. Each
5824 branch is then transformed recursively. */
5827 balance_case_nodes (head, parent)
5828 case_node_ptr *head;
5829 case_node_ptr parent;
5831 register case_node_ptr np;
5839 register case_node_ptr *npp;
5842 /* Count the number of entries on branch. Also count the ranges. */
5846 if (!tree_int_cst_equal (np->low, np->high))
5850 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5854 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5862 /* Split this list if it is long enough for that to help. */
5867 /* Find the place in the list that bisects the list's total cost,
5868 Here I gets half the total cost. */
5873 /* Skip nodes while their cost does not reach that amount. */
5874 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5875 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5876 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5879 npp = &(*npp)->right;
5884 /* Leave this branch lopsided, but optimize left-hand
5885 side and fill in `parent' fields for right-hand side. */
5887 np->parent = parent;
5888 balance_case_nodes (&np->left, np);
5889 for (; np->right; np = np->right)
5890 np->right->parent = np;
5894 /* If there are just three nodes, split at the middle one. */
5896 npp = &(*npp)->right;
5899 /* Find the place in the list that bisects the list's total cost,
5900 where ranges count as 2.
5901 Here I gets half the total cost. */
5902 i = (i + ranges + 1) / 2;
5905 /* Skip nodes while their cost does not reach that amount. */
5906 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5911 npp = &(*npp)->right;
5916 np->parent = parent;
5919 /* Optimize each of the two split parts. */
5920 balance_case_nodes (&np->left, np);
5921 balance_case_nodes (&np->right, np);
5925 /* Else leave this branch as one level,
5926 but fill in `parent' fields. */
5928 np->parent = parent;
5929 for (; np->right; np = np->right)
5930 np->right->parent = np;
5935 /* Search the parent sections of the case node tree
5936 to see if a test for the lower bound of NODE would be redundant.
5937 INDEX_TYPE is the type of the index expression.
5939 The instructions to generate the case decision tree are
5940 output in the same order as nodes are processed so it is
5941 known that if a parent node checks the range of the current
5942 node minus one that the current node is bounded at its lower
5943 span. Thus the test would be redundant. */
5946 node_has_low_bound (node, index_type)
5951 case_node_ptr pnode;
5953 /* If the lower bound of this node is the lowest value in the index type,
5954 we need not test it. */
5956 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5959 /* If this node has a left branch, the value at the left must be less
5960 than that at this node, so it cannot be bounded at the bottom and
5961 we need not bother testing any further. */
5966 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5967 node->low, integer_one_node));
5969 /* If the subtraction above overflowed, we can't verify anything.
5970 Otherwise, look for a parent that tests our value - 1. */
5972 if (! tree_int_cst_lt (low_minus_one, node->low))
5975 for (pnode = node->parent; pnode; pnode = pnode->parent)
5976 if (tree_int_cst_equal (low_minus_one, pnode->high))
5982 /* Search the parent sections of the case node tree
5983 to see if a test for the upper bound of NODE would be redundant.
5984 INDEX_TYPE is the type of the index expression.
5986 The instructions to generate the case decision tree are
5987 output in the same order as nodes are processed so it is
5988 known that if a parent node checks the range of the current
5989 node plus one that the current node is bounded at its upper
5990 span. Thus the test would be redundant. */
5993 node_has_high_bound (node, index_type)
5998 case_node_ptr pnode;
6000 /* If there is no upper bound, obviously no test is needed. */
6002 if (TYPE_MAX_VALUE (index_type) == NULL)
6005 /* If the upper bound of this node is the highest value in the type
6006 of the index expression, we need not test against it. */
6008 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6011 /* If this node has a right branch, the value at the right must be greater
6012 than that at this node, so it cannot be bounded at the top and
6013 we need not bother testing any further. */
6018 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6019 node->high, integer_one_node));
6021 /* If the addition above overflowed, we can't verify anything.
6022 Otherwise, look for a parent that tests our value + 1. */
6024 if (! tree_int_cst_lt (node->high, high_plus_one))
6027 for (pnode = node->parent; pnode; pnode = pnode->parent)
6028 if (tree_int_cst_equal (high_plus_one, pnode->low))
6034 /* Search the parent sections of the
6035 case node tree to see if both tests for the upper and lower
6036 bounds of NODE would be redundant. */
6039 node_is_bounded (node, index_type)
6043 return (node_has_low_bound (node, index_type)
6044 && node_has_high_bound (node, index_type));
6047 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6050 emit_jump_if_reachable (label)
6053 if (GET_CODE (get_last_insn ()) != BARRIER)
6057 /* Emit step-by-step code to select a case for the value of INDEX.
6058 The thus generated decision tree follows the form of the
6059 case-node binary tree NODE, whose nodes represent test conditions.
6060 INDEX_TYPE is the type of the index of the switch.
6062 Care is taken to prune redundant tests from the decision tree
6063 by detecting any boundary conditions already checked by
6064 emitted rtx. (See node_has_high_bound, node_has_low_bound
6065 and node_is_bounded, above.)
6067 Where the test conditions can be shown to be redundant we emit
6068 an unconditional jump to the target code. As a further
6069 optimization, the subordinates of a tree node are examined to
6070 check for bounded nodes. In this case conditional and/or
6071 unconditional jumps as a result of the boundary check for the
6072 current node are arranged to target the subordinates associated
6073 code for out of bound conditions on the current node.
6075 We can assume that when control reaches the code generated here,
6076 the index value has already been compared with the parents
6077 of this node, and determined to be on the same side of each parent
6078 as this node is. Thus, if this node tests for the value 51,
6079 and a parent tested for 52, we don't need to consider
6080 the possibility of a value greater than 51. If another parent
6081 tests for the value 50, then this node need not test anything. */
6084 emit_case_nodes (index, node, default_label, index_type)
6090 /* If INDEX has an unsigned type, we must make unsigned branches. */
6091 int unsignedp = TREE_UNSIGNED (index_type);
6092 enum machine_mode mode = GET_MODE (index);
6094 /* See if our parents have already tested everything for us.
6095 If they have, emit an unconditional jump for this node. */
6096 if (node_is_bounded (node, index_type))
6097 emit_jump (label_rtx (node->code_label));
6099 else if (tree_int_cst_equal (node->low, node->high))
6101 /* Node is single valued. First see if the index expression matches
6102 this node and then check our children, if any. */
6104 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6105 label_rtx (node->code_label), unsignedp);
6107 if (node->right != 0 && node->left != 0)
6109 /* This node has children on both sides.
6110 Dispatch to one side or the other
6111 by comparing the index value with this node's value.
6112 If one subtree is bounded, check that one first,
6113 so we can avoid real branches in the tree. */
6115 if (node_is_bounded (node->right, index_type))
6117 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6119 GT, NULL_RTX, mode, unsignedp, 0,
6120 label_rtx (node->right->code_label));
6121 emit_case_nodes (index, node->left, default_label, index_type);
6124 else if (node_is_bounded (node->left, index_type))
6126 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6128 LT, NULL_RTX, mode, unsignedp, 0,
6129 label_rtx (node->left->code_label));
6130 emit_case_nodes (index, node->right, default_label, index_type);
6135 /* Neither node is bounded. First distinguish the two sides;
6136 then emit the code for one side at a time. */
6139 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6141 /* See if the value is on the right. */
6142 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6144 GT, NULL_RTX, mode, unsignedp, 0,
6145 label_rtx (test_label));
6147 /* Value must be on the left.
6148 Handle the left-hand subtree. */
6149 emit_case_nodes (index, node->left, default_label, index_type);
6150 /* If left-hand subtree does nothing,
6152 emit_jump_if_reachable (default_label);
6154 /* Code branches here for the right-hand subtree. */
6155 expand_label (test_label);
6156 emit_case_nodes (index, node->right, default_label, index_type);
6160 else if (node->right != 0 && node->left == 0)
6162 /* Here we have a right child but no left so we issue conditional
6163 branch to default and process the right child.
6165 Omit the conditional branch to default if we it avoid only one
6166 right child; it costs too much space to save so little time. */
6168 if (node->right->right || node->right->left
6169 || !tree_int_cst_equal (node->right->low, node->right->high))
6171 if (!node_has_low_bound (node, index_type))
6173 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6176 LT, NULL_RTX, mode, unsignedp, 0,
6180 emit_case_nodes (index, node->right, default_label, index_type);
6183 /* We cannot process node->right normally
6184 since we haven't ruled out the numbers less than
6185 this node's value. So handle node->right explicitly. */
6186 do_jump_if_equal (index,
6187 expand_expr (node->right->low, NULL_RTX,
6189 label_rtx (node->right->code_label), unsignedp);
6192 else if (node->right == 0 && node->left != 0)
6194 /* Just one subtree, on the left. */
6196 #if 0 /* The following code and comment were formerly part
6197 of the condition here, but they didn't work
6198 and I don't understand what the idea was. -- rms. */
6199 /* If our "most probable entry" is less probable
6200 than the default label, emit a jump to
6201 the default label using condition codes
6202 already lying around. With no right branch,
6203 a branch-greater-than will get us to the default
6206 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6209 if (node->left->left || node->left->right
6210 || !tree_int_cst_equal (node->left->low, node->left->high))
6212 if (!node_has_high_bound (node, index_type))
6214 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6217 GT, NULL_RTX, mode, unsignedp, 0,
6221 emit_case_nodes (index, node->left, default_label, index_type);
6224 /* We cannot process node->left normally
6225 since we haven't ruled out the numbers less than
6226 this node's value. So handle node->left explicitly. */
6227 do_jump_if_equal (index,
6228 expand_expr (node->left->low, NULL_RTX,
6230 label_rtx (node->left->code_label), unsignedp);
6235 /* Node is a range. These cases are very similar to those for a single
6236 value, except that we do not start by testing whether this node
6237 is the one to branch to. */
6239 if (node->right != 0 && node->left != 0)
6241 /* Node has subtrees on both sides.
6242 If the right-hand subtree is bounded,
6243 test for it first, since we can go straight there.
6244 Otherwise, we need to make a branch in the control structure,
6245 then handle the two subtrees. */
6246 tree test_label = 0;
6249 if (node_is_bounded (node->right, index_type))
6250 /* Right hand node is fully bounded so we can eliminate any
6251 testing and branch directly to the target code. */
6252 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6254 GT, NULL_RTX, mode, unsignedp, 0,
6255 label_rtx (node->right->code_label));
6258 /* Right hand node requires testing.
6259 Branch to a label where we will handle it later. */
6261 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6262 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6264 GT, NULL_RTX, mode, unsignedp, 0,
6265 label_rtx (test_label));
6268 /* Value belongs to this node or to the left-hand subtree. */
6270 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6272 GE, NULL_RTX, mode, unsignedp, 0,
6273 label_rtx (node->code_label));
6275 /* Handle the left-hand subtree. */
6276 emit_case_nodes (index, node->left, default_label, index_type);
6278 /* If right node had to be handled later, do that now. */
6282 /* If the left-hand subtree fell through,
6283 don't let it fall into the right-hand subtree. */
6284 emit_jump_if_reachable (default_label);
6286 expand_label (test_label);
6287 emit_case_nodes (index, node->right, default_label, index_type);
6291 else if (node->right != 0 && node->left == 0)
6293 /* Deal with values to the left of this node,
6294 if they are possible. */
6295 if (!node_has_low_bound (node, index_type))
6297 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6299 LT, NULL_RTX, mode, unsignedp, 0,
6303 /* Value belongs to this node or to the right-hand subtree. */
6305 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6307 LE, NULL_RTX, mode, unsignedp, 0,
6308 label_rtx (node->code_label));
6310 emit_case_nodes (index, node->right, default_label, index_type);
6313 else if (node->right == 0 && node->left != 0)
6315 /* Deal with values to the right of this node,
6316 if they are possible. */
6317 if (!node_has_high_bound (node, index_type))
6319 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6321 GT, NULL_RTX, mode, unsignedp, 0,
6325 /* Value belongs to this node or to the left-hand subtree. */
6327 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6329 GE, NULL_RTX, mode, unsignedp, 0,
6330 label_rtx (node->code_label));
6332 emit_case_nodes (index, node->left, default_label, index_type);
6337 /* Node has no children so we check low and high bounds to remove
6338 redundant tests. Only one of the bounds can exist,
6339 since otherwise this node is bounded--a case tested already. */
6341 if (!node_has_high_bound (node, index_type))
6343 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6345 GT, NULL_RTX, mode, unsignedp, 0,
6349 if (!node_has_low_bound (node, index_type))
6351 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6353 LT, NULL_RTX, mode, unsignedp, 0,
6357 emit_jump (label_rtx (node->code_label));