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. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Functions and data structures for expanding case statements. */
69 /* Case label structure, used to hold info on labels within case
70 statements. We handle "range" labels; for a single-value label
71 as in C, the high and low limits are the same.
73 An AVL tree of case nodes is initially created, and later transformed
74 to a list linked via the RIGHT fields in the nodes. Nodes with
75 higher case values are later in the list.
77 Switch statements can be output in one of two forms. A branch table
78 is used if there are more than a few labels and the labels are dense
79 within the range between the smallest and largest case value. If a
80 branch table is used, no further manipulations are done with the case
83 The alternative to the use of a branch table is to generate a series
84 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
85 and PARENT fields to hold a binary tree. Initially the tree is
86 totally unbalanced, with everything on the right. We balance the tree
87 with nodes on the left having lower case values than the parent
88 and nodes on the right having higher values. We then output the tree
93 struct case_node *left; /* Left son in binary tree */
94 struct case_node *right; /* Right son in binary tree; also node chain */
95 struct case_node *parent; /* Parent of node in binary tree */
96 tree low; /* Lowest index value for this label */
97 tree high; /* Highest index value for this label */
98 tree code_label; /* Label to jump to when node matches */
102 typedef struct case_node case_node;
103 typedef struct case_node *case_node_ptr;
105 /* These are used by estimate_case_costs and balance_case_nodes. */
107 /* This must be a signed type, and non-ANSI compilers lack signed char. */
108 static short cost_table_[129];
109 static short *cost_table;
110 static int use_cost_table;
112 /* Stack of control and binding constructs we are currently inside.
114 These constructs begin when you call `expand_start_WHATEVER'
115 and end when you call `expand_end_WHATEVER'. This stack records
116 info about how the construct began that tells the end-function
117 what to do. It also may provide information about the construct
118 to alter the behavior of other constructs within the body.
119 For example, they may affect the behavior of C `break' and `continue'.
121 Each construct gets one `struct nesting' object.
122 All of these objects are chained through the `all' field.
123 `nesting_stack' points to the first object (innermost construct).
124 The position of an entry on `nesting_stack' is in its `depth' field.
126 Each type of construct has its own individual stack.
127 For example, loops have `loop_stack'. Each object points to the
128 next object of the same type through the `next' field.
130 Some constructs are visible to `break' exit-statements and others
131 are not. Which constructs are visible depends on the language.
132 Therefore, the data structure allows each construct to be visible
133 or not, according to the args given when the construct is started.
134 The construct is visible if the `exit_label' field is non-null.
135 In that case, the value should be a CODE_LABEL rtx. */
140 struct nesting *next;
145 /* For conds (if-then and if-then-else statements). */
148 /* Label for the end of the if construct.
149 There is none if EXITFLAG was not set
150 and no `else' has been seen yet. */
152 /* Label for the end of this alternative.
153 This may be the end of the if or the next else/elseif. */
159 /* Label at the top of the loop; place to loop back to. */
161 /* Label at the end of the whole construct. */
163 /* Label before a jump that branches to the end of the whole
164 construct. This is where destructors go if any. */
166 /* Label for `continue' statement to jump to;
167 this is in front of the stepper of the loop. */
170 /* For variable binding contours. */
173 /* Sequence number of this binding contour within the function,
174 in order of entry. */
175 int block_start_count;
176 /* Nonzero => value to restore stack to on exit. */
178 /* The NOTE that starts this contour.
179 Used by expand_goto to check whether the destination
180 is within each contour or not. */
182 /* Innermost containing binding contour that has a stack level. */
183 struct nesting *innermost_stack_block;
184 /* List of cleanups to be run on exit from this contour.
185 This is a list of expressions to be evaluated.
186 The TREE_PURPOSE of each link is the ..._DECL node
187 which the cleanup pertains to. */
189 /* List of cleanup-lists of blocks containing this block,
190 as they were at the locus where this block appears.
191 There is an element for each containing block,
192 ordered innermost containing block first.
193 The tail of this list can be 0,
194 if all remaining elements would be empty lists.
195 The element's TREE_VALUE is the cleanup-list of that block,
196 which may be null. */
198 /* Chain of labels defined inside this binding contour.
199 For contours that have stack levels or cleanups. */
200 struct label_chain *label_chain;
201 /* Number of function calls seen, as of start of this block. */
202 int n_function_calls;
203 /* Nonzero if this is associated with a EH region. */
204 int exception_region;
205 /* The saved target_temp_slot_level from our outer block.
206 We may reset target_temp_slot_level to be the level of
207 this block, if that is done, target_temp_slot_level
208 reverts to the saved target_temp_slot_level at the very
210 int block_target_temp_slot_level;
211 /* True if we are currently emitting insns in an area of
212 output code that is controlled by a conditional
213 expression. This is used by the cleanup handling code to
214 generate conditional cleanup actions. */
215 int conditional_code;
216 /* A place to move the start of the exception region for any
217 of the conditional cleanups, must be at the end or after
218 the start of the last unconditional cleanup, and before any
219 conditional branch points. */
220 rtx last_unconditional_cleanup;
221 /* When in a conditional context, this is the specific
222 cleanup list associated with last_unconditional_cleanup,
223 where we place the conditionalized cleanups. */
226 /* For switch (C) or case (Pascal) statements,
227 and also for dummies (see `expand_start_case_dummy'). */
230 /* The insn after which the case dispatch should finally
231 be emitted. Zero for a dummy. */
233 /* A list of case labels; it is first built as an AVL tree.
234 During expand_end_case, this is converted to a list, and may be
235 rearranged into a nearly balanced binary tree. */
236 struct case_node *case_list;
237 /* Label to jump to if no case matches. */
239 /* The expression to be dispatched on. */
241 /* Type that INDEX_EXPR should be converted to. */
243 /* Number of range exprs in case statement. */
245 /* Name of this kind of statement, for warnings. */
246 const char *printname;
247 /* Used to save no_line_numbers till we see the first case label.
248 We set this to -1 when we see the first case label in this
250 int line_number_status;
255 /* Allocate and return a new `struct nesting'. */
257 #define ALLOC_NESTING() \
258 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
260 /* Pop the nesting stack element by element until we pop off
261 the element which is at the top of STACK.
262 Update all the other stacks, popping off elements from them
263 as we pop them from nesting_stack. */
265 #define POPSTACK(STACK) \
266 do { struct nesting *target = STACK; \
267 struct nesting *this; \
268 do { this = nesting_stack; \
269 if (loop_stack == this) \
270 loop_stack = loop_stack->next; \
271 if (cond_stack == this) \
272 cond_stack = cond_stack->next; \
273 if (block_stack == this) \
274 block_stack = block_stack->next; \
275 if (stack_block_stack == this) \
276 stack_block_stack = stack_block_stack->next; \
277 if (case_stack == this) \
278 case_stack = case_stack->next; \
279 nesting_depth = nesting_stack->depth - 1; \
280 nesting_stack = this->all; \
281 obstack_free (&stmt_obstack, this); } \
282 while (this != target); } while (0)
284 /* In some cases it is impossible to generate code for a forward goto
285 until the label definition is seen. This happens when it may be necessary
286 for the goto to reset the stack pointer: we don't yet know how to do that.
287 So expand_goto puts an entry on this fixup list.
288 Each time a binding contour that resets the stack is exited,
290 If the target label has now been defined, we can insert the proper code. */
294 /* Points to following fixup. */
295 struct goto_fixup *next;
296 /* Points to the insn before the jump insn.
297 If more code must be inserted, it goes after this insn. */
299 /* The LABEL_DECL that this jump is jumping to, or 0
300 for break, continue or return. */
302 /* The BLOCK for the place where this goto was found. */
304 /* The CODE_LABEL rtx that this is jumping to. */
306 /* Number of binding contours started in current function
307 before the label reference. */
308 int block_start_count;
309 /* The outermost stack level that should be restored for this jump.
310 Each time a binding contour that resets the stack is exited,
311 if the target label is *not* yet defined, this slot is updated. */
313 /* List of lists of cleanup expressions to be run by this goto.
314 There is one element for each block that this goto is within.
315 The tail of this list can be 0,
316 if all remaining elements would be empty.
317 The TREE_VALUE contains the cleanup list of that block as of the
318 time this goto was seen.
319 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
320 tree cleanup_list_list;
323 /* Within any binding contour that must restore a stack level,
324 all labels are recorded with a chain of these structures. */
328 /* Points to following fixup. */
329 struct label_chain *next;
335 /* Chain of all pending binding contours. */
336 struct nesting *x_block_stack;
338 /* If any new stacks are added here, add them to POPSTACKS too. */
340 /* Chain of all pending binding contours that restore stack levels
342 struct nesting *x_stack_block_stack;
344 /* Chain of all pending conditional statements. */
345 struct nesting *x_cond_stack;
347 /* Chain of all pending loops. */
348 struct nesting *x_loop_stack;
350 /* Chain of all pending case or switch statements. */
351 struct nesting *x_case_stack;
353 /* Separate chain including all of the above,
354 chained through the `all' field. */
355 struct nesting *x_nesting_stack;
357 /* Number of entries on nesting_stack now. */
360 /* Number of binding contours started so far in this function. */
361 int x_block_start_count;
363 /* Each time we expand an expression-statement,
364 record the expr's type and its RTL value here. */
365 tree x_last_expr_type;
366 rtx x_last_expr_value;
368 /* Nonzero if within a ({...}) grouping, in which case we must
369 always compute a value for each expr-stmt in case it is the last one. */
370 int x_expr_stmts_for_value;
372 /* Filename and line number of last line-number note,
373 whether we actually emitted it or not. */
374 const char *x_emit_filename;
377 struct goto_fixup *x_goto_fixup_chain;
380 #define block_stack (cfun->stmt->x_block_stack)
381 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
382 #define cond_stack (cfun->stmt->x_cond_stack)
383 #define loop_stack (cfun->stmt->x_loop_stack)
384 #define case_stack (cfun->stmt->x_case_stack)
385 #define nesting_stack (cfun->stmt->x_nesting_stack)
386 #define nesting_depth (cfun->stmt->x_nesting_depth)
387 #define current_block_start_count (cfun->stmt->x_block_start_count)
388 #define last_expr_type (cfun->stmt->x_last_expr_type)
389 #define last_expr_value (cfun->stmt->x_last_expr_value)
390 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
391 #define emit_filename (cfun->stmt->x_emit_filename)
392 #define emit_lineno (cfun->stmt->x_emit_lineno)
393 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
395 /* Non-zero if we are using EH to handle cleanus. */
396 static int using_eh_for_cleanups_p = 0;
398 /* Character strings, each containing a single decimal digit. */
399 static char *digit_strings[10];
401 static int n_occurrences PARAMS ((int, const char *));
402 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
403 static int expand_fixup PARAMS ((tree, rtx, rtx));
404 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
405 static void expand_nl_goto_receiver PARAMS ((void));
406 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
407 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
409 static void expand_null_return_1 PARAMS ((rtx, int));
410 static void expand_value_return PARAMS ((rtx));
411 static int tail_recursion_args PARAMS ((tree, tree));
412 static void expand_cleanups PARAMS ((tree, tree, int, int));
413 static void check_seenlabel PARAMS ((void));
414 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
415 static int estimate_case_costs PARAMS ((case_node_ptr));
416 static void group_case_nodes PARAMS ((case_node_ptr));
417 static void balance_case_nodes PARAMS ((case_node_ptr *,
419 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
420 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
421 static int node_is_bounded PARAMS ((case_node_ptr, tree));
422 static void emit_jump_if_reachable PARAMS ((rtx));
423 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
424 static int add_case_node PARAMS ((tree, tree, tree, tree *));
425 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
426 static void mark_cond_nesting PARAMS ((struct nesting *));
427 static void mark_loop_nesting PARAMS ((struct nesting *));
428 static void mark_block_nesting PARAMS ((struct nesting *));
429 static void mark_case_nesting PARAMS ((struct nesting *));
430 static void mark_case_node PARAMS ((struct case_node *));
431 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
435 using_eh_for_cleanups ()
437 using_eh_for_cleanups_p = 1;
440 /* Mark N (known to be a cond-nesting) for GC. */
443 mark_cond_nesting (n)
448 ggc_mark_rtx (n->exit_label);
449 ggc_mark_rtx (n->data.cond.endif_label);
450 ggc_mark_rtx (n->data.cond.next_label);
456 /* Mark N (known to be a loop-nesting) for GC. */
459 mark_loop_nesting (n)
465 ggc_mark_rtx (n->exit_label);
466 ggc_mark_rtx (n->data.loop.start_label);
467 ggc_mark_rtx (n->data.loop.end_label);
468 ggc_mark_rtx (n->data.loop.alt_end_label);
469 ggc_mark_rtx (n->data.loop.continue_label);
475 /* Mark N (known to be a block-nesting) for GC. */
478 mark_block_nesting (n)
483 struct label_chain *l;
485 ggc_mark_rtx (n->exit_label);
486 ggc_mark_rtx (n->data.block.stack_level);
487 ggc_mark_rtx (n->data.block.first_insn);
488 ggc_mark_tree (n->data.block.cleanups);
489 ggc_mark_tree (n->data.block.outer_cleanups);
491 for (l = n->data.block.label_chain; l != NULL; l = l->next)
492 ggc_mark_tree (l->label);
494 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
496 /* ??? cleanup_ptr never points outside the stack, does it? */
502 /* Mark N (known to be a case-nesting) for GC. */
505 mark_case_nesting (n)
510 ggc_mark_rtx (n->exit_label);
511 ggc_mark_rtx (n->data.case_stmt.start);
513 ggc_mark_tree (n->data.case_stmt.default_label);
514 ggc_mark_tree (n->data.case_stmt.index_expr);
515 ggc_mark_tree (n->data.case_stmt.nominal_type);
517 mark_case_node (n->data.case_stmt.case_list);
530 ggc_mark_tree (c->low);
531 ggc_mark_tree (c->high);
532 ggc_mark_tree (c->code_label);
534 mark_case_node (c->right);
535 mark_case_node (c->left);
543 struct goto_fixup *g;
548 ggc_mark_rtx (g->before_jump);
549 ggc_mark_tree (g->target);
550 ggc_mark_tree (g->context);
551 ggc_mark_rtx (g->target_rtl);
552 ggc_mark_rtx (g->stack_level);
553 ggc_mark_tree (g->cleanup_list_list);
559 /* Clear out all parts of the state in F that can safely be discarded
560 after the function has been compiled, to let garbage collection
561 reclaim the memory. */
567 /* We're about to free the function obstack. If we hold pointers to
568 things allocated there, then we'll try to mark them when we do
569 GC. So, we clear them out here explicitly. */
579 struct stmt_status *p;
584 mark_block_nesting (p->x_block_stack);
585 mark_cond_nesting (p->x_cond_stack);
586 mark_loop_nesting (p->x_loop_stack);
587 mark_case_nesting (p->x_case_stack);
589 ggc_mark_tree (p->x_last_expr_type);
590 /* last_epxr_value is only valid if last_expr_type is nonzero. */
591 if (p->x_last_expr_type)
592 ggc_mark_rtx (p->x_last_expr_value);
594 mark_goto_fixup (p->x_goto_fixup_chain);
602 gcc_obstack_init (&stmt_obstack);
604 for (i = 0; i < 10; i++)
606 digit_strings[i] = ggc_alloc_string (NULL, 1);
607 digit_strings[i][0] = '0' + i;
609 ggc_add_string_root (digit_strings, 10);
613 init_stmt_for_function ()
615 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
617 /* We are not currently within any block, conditional, loop or case. */
619 stack_block_stack = 0;
626 current_block_start_count = 0;
628 /* No gotos have been expanded yet. */
629 goto_fixup_chain = 0;
631 /* We are not processing a ({...}) grouping. */
632 expr_stmts_for_value = 0;
634 last_expr_value = NULL_RTX;
637 /* Return nonzero if anything is pushed on the loop, condition, or case
642 return cond_stack || loop_stack || case_stack;
645 /* Record the current file and line. Called from emit_line_note. */
647 set_file_and_line_for_stmt (file, line)
651 /* If we're outputting an inline function, and we add a line note,
652 there may be no CFUN->STMT information. So, there's no need to
656 emit_filename = file;
661 /* Emit a no-op instruction. */
668 last_insn = get_last_insn ();
670 && (GET_CODE (last_insn) == CODE_LABEL
671 || (GET_CODE (last_insn) == NOTE
672 && prev_real_insn (last_insn) == 0)))
673 emit_insn (gen_nop ());
676 /* Return the rtx-label that corresponds to a LABEL_DECL,
677 creating it if necessary. */
683 if (TREE_CODE (label) != LABEL_DECL)
686 if (DECL_RTL (label))
687 return DECL_RTL (label);
689 return DECL_RTL (label) = gen_label_rtx ();
692 /* Add an unconditional jump to LABEL as the next sequential instruction. */
698 do_pending_stack_adjust ();
699 emit_jump_insn (gen_jump (label));
703 /* Emit code to jump to the address
704 specified by the pointer expression EXP. */
707 expand_computed_goto (exp)
710 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
712 #ifdef POINTERS_EXTEND_UNSIGNED
713 x = convert_memory_address (Pmode, x);
717 /* Be sure the function is executable. */
718 if (current_function_check_memory_usage)
719 emit_library_call (chkr_check_exec_libfunc, 1,
720 VOIDmode, 1, x, ptr_mode);
722 do_pending_stack_adjust ();
723 emit_indirect_jump (x);
725 current_function_has_computed_jump = 1;
728 /* Handle goto statements and the labels that they can go to. */
730 /* Specify the location in the RTL code of a label LABEL,
731 which is a LABEL_DECL tree node.
733 This is used for the kind of label that the user can jump to with a
734 goto statement, and for alternatives of a switch or case statement.
735 RTL labels generated for loops and conditionals don't go through here;
736 they are generated directly at the RTL level, by other functions below.
738 Note that this has nothing to do with defining label *names*.
739 Languages vary in how they do that and what that even means. */
745 struct label_chain *p;
747 do_pending_stack_adjust ();
748 emit_label (label_rtx (label));
749 if (DECL_NAME (label))
750 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
752 if (stack_block_stack != 0)
754 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
755 p->next = stack_block_stack->data.block.label_chain;
756 stack_block_stack->data.block.label_chain = p;
761 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
762 from nested functions. */
765 declare_nonlocal_label (label)
768 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
770 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
771 LABEL_PRESERVE_P (label_rtx (label)) = 1;
772 if (nonlocal_goto_handler_slots == 0)
774 emit_stack_save (SAVE_NONLOCAL,
775 &nonlocal_goto_stack_level,
776 PREV_INSN (tail_recursion_reentry));
778 nonlocal_goto_handler_slots
779 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
782 /* Generate RTL code for a `goto' statement with target label LABEL.
783 LABEL should be a LABEL_DECL tree node that was or will later be
784 defined with `expand_label'. */
792 /* Check for a nonlocal goto to a containing function. */
793 context = decl_function_context (label);
794 if (context != 0 && context != current_function_decl)
796 struct function *p = find_function_data (context);
797 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
798 rtx handler_slot, static_chain, save_area;
801 /* Find the corresponding handler slot for this label. */
802 handler_slot = p->x_nonlocal_goto_handler_slots;
803 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
804 link = TREE_CHAIN (link))
805 handler_slot = XEXP (handler_slot, 1);
806 handler_slot = XEXP (handler_slot, 0);
808 p->has_nonlocal_label = 1;
809 current_function_has_nonlocal_goto = 1;
810 LABEL_REF_NONLOCAL_P (label_ref) = 1;
812 /* Copy the rtl for the slots so that they won't be shared in
813 case the virtual stack vars register gets instantiated differently
814 in the parent than in the child. */
816 static_chain = copy_to_reg (lookup_static_chain (label));
818 /* Get addr of containing function's current nonlocal goto handler,
819 which will do any cleanups and then jump to the label. */
820 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
821 virtual_stack_vars_rtx,
824 /* Get addr of containing function's nonlocal save area. */
825 save_area = p->x_nonlocal_goto_stack_level;
827 save_area = replace_rtx (copy_rtx (save_area),
828 virtual_stack_vars_rtx, static_chain);
830 #if HAVE_nonlocal_goto
831 if (HAVE_nonlocal_goto)
832 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
833 save_area, label_ref));
837 /* Restore frame pointer for containing function.
838 This sets the actual hard register used for the frame pointer
839 to the location of the function's incoming static chain info.
840 The non-local goto handler will then adjust it to contain the
841 proper value and reload the argument pointer, if needed. */
842 emit_move_insn (hard_frame_pointer_rtx, static_chain);
843 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
845 /* USE of hard_frame_pointer_rtx added for consistency;
846 not clear if really needed. */
847 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
848 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
849 emit_indirect_jump (handler_slot);
853 expand_goto_internal (label, label_rtx (label), NULL_RTX);
856 /* Generate RTL code for a `goto' statement with target label BODY.
857 LABEL should be a LABEL_REF.
858 LAST_INSN, if non-0, is the rtx we should consider as the last
859 insn emitted (for the purposes of cleaning up a return). */
862 expand_goto_internal (body, label, last_insn)
867 struct nesting *block;
870 if (GET_CODE (label) != CODE_LABEL)
873 /* If label has already been defined, we can tell now
874 whether and how we must alter the stack level. */
876 if (PREV_INSN (label) != 0)
878 /* Find the innermost pending block that contains the label.
879 (Check containment by comparing insn-uids.)
880 Then restore the outermost stack level within that block,
881 and do cleanups of all blocks contained in it. */
882 for (block = block_stack; block; block = block->next)
884 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
886 if (block->data.block.stack_level != 0)
887 stack_level = block->data.block.stack_level;
888 /* Execute the cleanups for blocks we are exiting. */
889 if (block->data.block.cleanups != 0)
891 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
892 do_pending_stack_adjust ();
898 /* Ensure stack adjust isn't done by emit_jump, as this
899 would clobber the stack pointer. This one should be
900 deleted as dead by flow. */
901 clear_pending_stack_adjust ();
902 do_pending_stack_adjust ();
904 /* Don't do this adjust if it's to the end label and this function
905 is to return with a depressed stack pointer. */
906 if (label == return_label
907 && (((TREE_CODE (TREE_TYPE (current_function_decl))
909 && (TYPE_RETURNS_STACK_DEPRESSED
910 (TREE_TYPE (current_function_decl))))))
913 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
916 if (body != 0 && DECL_TOO_LATE (body))
917 error ("jump to `%s' invalidly jumps into binding contour",
918 IDENTIFIER_POINTER (DECL_NAME (body)));
920 /* Label not yet defined: may need to put this goto
921 on the fixup list. */
922 else if (! expand_fixup (body, label, last_insn))
924 /* No fixup needed. Record that the label is the target
925 of at least one goto that has no fixup. */
927 TREE_ADDRESSABLE (body) = 1;
933 /* Generate if necessary a fixup for a goto
934 whose target label in tree structure (if any) is TREE_LABEL
935 and whose target in rtl is RTL_LABEL.
937 If LAST_INSN is nonzero, we pretend that the jump appears
938 after insn LAST_INSN instead of at the current point in the insn stream.
940 The fixup will be used later to insert insns just before the goto.
941 Those insns will restore the stack level as appropriate for the
942 target label, and will (in the case of C++) also invoke any object
943 destructors which have to be invoked when we exit the scopes which
944 are exited by the goto.
946 Value is nonzero if a fixup is made. */
949 expand_fixup (tree_label, rtl_label, last_insn)
954 struct nesting *block, *end_block;
956 /* See if we can recognize which block the label will be output in.
957 This is possible in some very common cases.
958 If we succeed, set END_BLOCK to that block.
959 Otherwise, set it to 0. */
962 && (rtl_label == cond_stack->data.cond.endif_label
963 || rtl_label == cond_stack->data.cond.next_label))
964 end_block = cond_stack;
965 /* If we are in a loop, recognize certain labels which
966 are likely targets. This reduces the number of fixups
967 we need to create. */
969 && (rtl_label == loop_stack->data.loop.start_label
970 || rtl_label == loop_stack->data.loop.end_label
971 || rtl_label == loop_stack->data.loop.continue_label))
972 end_block = loop_stack;
976 /* Now set END_BLOCK to the binding level to which we will return. */
980 struct nesting *next_block = end_block->all;
983 /* First see if the END_BLOCK is inside the innermost binding level.
984 If so, then no cleanups or stack levels are relevant. */
985 while (next_block && next_block != block)
986 next_block = next_block->all;
991 /* Otherwise, set END_BLOCK to the innermost binding level
992 which is outside the relevant control-structure nesting. */
993 next_block = block_stack->next;
994 for (block = block_stack; block != end_block; block = block->all)
995 if (block == next_block)
996 next_block = next_block->next;
997 end_block = next_block;
1000 /* Does any containing block have a stack level or cleanups?
1001 If not, no fixup is needed, and that is the normal case
1002 (the only case, for standard C). */
1003 for (block = block_stack; block != end_block; block = block->next)
1004 if (block->data.block.stack_level != 0
1005 || block->data.block.cleanups != 0)
1008 if (block != end_block)
1010 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1011 struct goto_fixup *fixup
1012 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1013 /* In case an old stack level is restored, make sure that comes
1014 after any pending stack adjust. */
1015 /* ?? If the fixup isn't to come at the present position,
1016 doing the stack adjust here isn't useful. Doing it with our
1017 settings at that location isn't useful either. Let's hope
1020 do_pending_stack_adjust ();
1021 fixup->target = tree_label;
1022 fixup->target_rtl = rtl_label;
1024 /* Create a BLOCK node and a corresponding matched set of
1025 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1026 this point. The notes will encapsulate any and all fixup
1027 code which we might later insert at this point in the insn
1028 stream. Also, the BLOCK node will be the parent (i.e. the
1029 `SUPERBLOCK') of any other BLOCK nodes which we might create
1030 later on when we are expanding the fixup code.
1032 Note that optimization passes (including expand_end_loop)
1033 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1034 as a placeholder. */
1037 register rtx original_before_jump
1038 = last_insn ? last_insn : get_last_insn ();
1043 block = make_node (BLOCK);
1044 TREE_USED (block) = 1;
1046 if (!cfun->x_whole_function_mode_p)
1047 insert_block (block);
1051 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1052 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1057 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1058 if (cfun->x_whole_function_mode_p)
1059 NOTE_BLOCK (start) = block;
1060 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1061 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1062 if (cfun->x_whole_function_mode_p)
1063 NOTE_BLOCK (end) = block;
1064 fixup->context = block;
1066 emit_insns_after (start, original_before_jump);
1069 fixup->block_start_count = current_block_start_count;
1070 fixup->stack_level = 0;
1071 fixup->cleanup_list_list
1072 = ((block->data.block.outer_cleanups
1073 || block->data.block.cleanups)
1074 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1075 block->data.block.outer_cleanups)
1077 fixup->next = goto_fixup_chain;
1078 goto_fixup_chain = fixup;
1084 /* Expand any needed fixups in the outputmost binding level of the
1085 function. FIRST_INSN is the first insn in the function. */
1088 expand_fixups (first_insn)
1091 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1094 /* When exiting a binding contour, process all pending gotos requiring fixups.
1095 THISBLOCK is the structure that describes the block being exited.
1096 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1097 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1098 FIRST_INSN is the insn that began this contour.
1100 Gotos that jump out of this contour must restore the
1101 stack level and do the cleanups before actually jumping.
1103 DONT_JUMP_IN nonzero means report error there is a jump into this
1104 contour from before the beginning of the contour.
1105 This is also done if STACK_LEVEL is nonzero. */
1108 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1109 struct nesting *thisblock;
1115 register struct goto_fixup *f, *prev;
1117 /* F is the fixup we are considering; PREV is the previous one. */
1118 /* We run this loop in two passes so that cleanups of exited blocks
1119 are run first, and blocks that are exited are marked so
1122 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1124 /* Test for a fixup that is inactive because it is already handled. */
1125 if (f->before_jump == 0)
1127 /* Delete inactive fixup from the chain, if that is easy to do. */
1129 prev->next = f->next;
1131 /* Has this fixup's target label been defined?
1132 If so, we can finalize it. */
1133 else if (PREV_INSN (f->target_rtl) != 0)
1135 register rtx cleanup_insns;
1137 /* If this fixup jumped into this contour from before the beginning
1138 of this contour, report an error. This code used to use
1139 the first non-label insn after f->target_rtl, but that's
1140 wrong since such can be added, by things like put_var_into_stack
1141 and have INSN_UIDs that are out of the range of the block. */
1142 /* ??? Bug: this does not detect jumping in through intermediate
1143 blocks that have stack levels or cleanups.
1144 It detects only a problem with the innermost block
1145 around the label. */
1147 && (dont_jump_in || stack_level || cleanup_list)
1148 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1149 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1150 && ! DECL_ERROR_ISSUED (f->target))
1152 error_with_decl (f->target,
1153 "label `%s' used before containing binding contour");
1154 /* Prevent multiple errors for one label. */
1155 DECL_ERROR_ISSUED (f->target) = 1;
1158 /* We will expand the cleanups into a sequence of their own and
1159 then later on we will attach this new sequence to the insn
1160 stream just ahead of the actual jump insn. */
1164 /* Temporarily restore the lexical context where we will
1165 logically be inserting the fixup code. We do this for the
1166 sake of getting the debugging information right. */
1169 set_block (f->context);
1171 /* Expand the cleanups for blocks this jump exits. */
1172 if (f->cleanup_list_list)
1175 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1176 /* Marked elements correspond to blocks that have been closed.
1177 Do their cleanups. */
1178 if (TREE_ADDRESSABLE (lists)
1179 && TREE_VALUE (lists) != 0)
1181 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1182 /* Pop any pushes done in the cleanups,
1183 in case function is about to return. */
1184 do_pending_stack_adjust ();
1188 /* Restore stack level for the biggest contour that this
1189 jump jumps out of. */
1191 && ! (f->target_rtl == return_label
1192 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1194 && (TYPE_RETURNS_STACK_DEPRESSED
1195 (TREE_TYPE (current_function_decl))))))
1196 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1198 /* Finish up the sequence containing the insns which implement the
1199 necessary cleanups, and then attach that whole sequence to the
1200 insn stream just ahead of the actual jump insn. Attaching it
1201 at that point insures that any cleanups which are in fact
1202 implicit C++ object destructions (which must be executed upon
1203 leaving the block) appear (to the debugger) to be taking place
1204 in an area of the generated code where the object(s) being
1205 destructed are still "in scope". */
1207 cleanup_insns = get_insns ();
1211 emit_insns_after (cleanup_insns, f->before_jump);
1217 /* For any still-undefined labels, do the cleanups for this block now.
1218 We must do this now since items in the cleanup list may go out
1219 of scope when the block ends. */
1220 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1221 if (f->before_jump != 0
1222 && PREV_INSN (f->target_rtl) == 0
1223 /* Label has still not appeared. If we are exiting a block with
1224 a stack level to restore, that started before the fixup,
1225 mark this stack level as needing restoration
1226 when the fixup is later finalized. */
1228 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1229 means the label is undefined. That's erroneous, but possible. */
1230 && (thisblock->data.block.block_start_count
1231 <= f->block_start_count))
1233 tree lists = f->cleanup_list_list;
1236 for (; lists; lists = TREE_CHAIN (lists))
1237 /* If the following elt. corresponds to our containing block
1238 then the elt. must be for this block. */
1239 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1243 set_block (f->context);
1244 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1245 do_pending_stack_adjust ();
1246 cleanup_insns = get_insns ();
1249 if (cleanup_insns != 0)
1251 = emit_insns_after (cleanup_insns, f->before_jump);
1253 f->cleanup_list_list = TREE_CHAIN (lists);
1257 f->stack_level = stack_level;
1261 /* Return the number of times character C occurs in string S. */
1263 n_occurrences (c, s)
1273 /* Generate RTL for an asm statement (explicit assembler code).
1274 BODY is a STRING_CST node containing the assembler code text,
1275 or an ADDR_EXPR containing a STRING_CST. */
1281 if (current_function_check_memory_usage)
1283 error ("`asm' cannot be used in function where memory usage is checked");
1287 if (TREE_CODE (body) == ADDR_EXPR)
1288 body = TREE_OPERAND (body, 0);
1290 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1291 TREE_STRING_POINTER (body)));
1295 /* Generate RTL for an asm statement with arguments.
1296 STRING is the instruction template.
1297 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1298 Each output or input has an expression in the TREE_VALUE and
1299 a constraint-string in the TREE_PURPOSE.
1300 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1301 that is clobbered by this insn.
1303 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1304 Some elements of OUTPUTS may be replaced with trees representing temporary
1305 values. The caller should copy those temporary values to the originally
1308 VOL nonzero means the insn is volatile; don't optimize it. */
1311 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1312 tree string, outputs, inputs, clobbers;
1314 const char *filename;
1317 rtvec argvec, constraints;
1319 int ninputs = list_length (inputs);
1320 int noutputs = list_length (outputs);
1325 /* Vector of RTX's of evaluated output operands. */
1326 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1327 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1328 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 enum machine_mode *inout_mode
1330 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1331 /* The insn we have emitted. */
1334 /* An ASM with no outputs needs to be treated as volatile, for now. */
1338 if (current_function_check_memory_usage)
1340 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1344 #ifdef MD_ASM_CLOBBERS
1345 /* Sometimes we wish to automatically clobber registers across an asm.
1346 Case in point is when the i386 backend moved from cc0 to a hard reg --
1347 maintaining source-level compatability means automatically clobbering
1348 the flags register. */
1349 MD_ASM_CLOBBERS (clobbers);
1352 if (current_function_check_memory_usage)
1354 error ("`asm' cannot be used in function where memory usage is checked");
1358 /* Count the number of meaningful clobbered registers, ignoring what
1359 we would ignore later. */
1361 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1363 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1365 i = decode_reg_name (regname);
1366 if (i >= 0 || i == -4)
1369 error ("unknown register name `%s' in `asm'", regname);
1374 /* Check that the number of alternatives is constant across all
1376 if (outputs || inputs)
1378 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1379 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1382 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1384 error ("too many alternatives in `asm'");
1391 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1393 if (n_occurrences (',', constraint) != nalternatives)
1395 error ("operand constraints for `asm' differ in number of alternatives");
1399 if (TREE_CHAIN (tmp))
1400 tmp = TREE_CHAIN (tmp);
1402 tmp = next, next = 0;
1406 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1408 tree val = TREE_VALUE (tail);
1409 tree type = TREE_TYPE (val);
1418 /* If there's an erroneous arg, emit no insn. */
1419 if (TREE_TYPE (val) == error_mark_node)
1422 /* Make sure constraint has `=' and does not have `+'. Also, see
1423 if it allows any register. Be liberal on the latter test, since
1424 the worst that happens if we get it wrong is we issue an error
1427 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1428 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1430 /* Allow the `=' or `+' to not be at the beginning of the string,
1431 since it wasn't explicitly documented that way, and there is a
1432 large body of code that puts it last. Swap the character to
1433 the front, so as not to uglify any place else. */
1437 if ((p = strchr (constraint, '=')) != NULL)
1439 if ((p = strchr (constraint, '+')) != NULL)
1442 error ("output operand constraint lacks `='");
1446 if (p != constraint)
1449 bcopy (constraint, constraint+1, p-constraint);
1452 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1455 is_inout = constraint[0] == '+';
1456 /* Replace '+' with '='. */
1457 constraint[0] = '=';
1458 /* Make sure we can specify the matching operand. */
1459 if (is_inout && i > 9)
1461 error ("output operand constraint %d contains `+'", i);
1465 for (j = 1; j < c_len; j++)
1466 switch (constraint[j])
1470 error ("operand constraint contains '+' or '=' at illegal position.");
1474 if (i + 1 == ninputs + noutputs)
1476 error ("`%%' constraint used with last operand");
1481 case '?': case '!': case '*': case '&':
1482 case 'E': case 'F': case 'G': case 'H':
1483 case 's': case 'i': case 'n':
1484 case 'I': case 'J': case 'K': case 'L': case 'M':
1485 case 'N': case 'O': case 'P': case ',':
1488 case '0': case '1': case '2': case '3': case '4':
1489 case '5': case '6': case '7': case '8': case '9':
1490 error ("matching constraint not valid in output operand");
1493 case 'V': case 'm': case 'o':
1498 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1499 excepting those that expand_call created. So match memory
1514 if (! ISALPHA (constraint[j]))
1516 error ("invalid punctuation `%c' in constraint",
1520 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1522 #ifdef EXTRA_CONSTRAINT
1525 /* Otherwise we can't assume anything about the nature of
1526 the constraint except that it isn't purely registers.
1527 Treat it like "g" and hope for the best. */
1535 /* If an output operand is not a decl or indirect ref and our constraint
1536 allows a register, make a temporary to act as an intermediate.
1537 Make the asm insn write into that, then our caller will copy it to
1538 the real output operand. Likewise for promoted variables. */
1540 real_output_rtx[i] = NULL_RTX;
1541 if ((TREE_CODE (val) == INDIRECT_REF
1544 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1545 && ! (GET_CODE (DECL_RTL (val)) == REG
1546 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1551 mark_addressable (TREE_VALUE (tail));
1554 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1555 EXPAND_MEMORY_USE_WO);
1557 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1558 error ("output number %d not directly addressable", i);
1559 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1561 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1562 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1564 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1569 output_rtx[i] = assign_temp (type, 0, 0, 1);
1570 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1575 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1576 inout_opnum[ninout++] = i;
1581 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1583 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1587 /* Make vectors for the expression-rtx and constraint strings. */
1589 argvec = rtvec_alloc (ninputs);
1590 constraints = rtvec_alloc (ninputs);
1592 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1593 empty_string, 0, argvec, constraints,
1596 MEM_VOLATILE_P (body) = vol;
1598 /* Eval the inputs and put them into ARGVEC.
1599 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1602 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1605 int allows_reg = 0, allows_mem = 0;
1606 char *constraint, *orig_constraint;
1610 /* If there's an erroneous arg, emit no insn,
1611 because the ASM_INPUT would get VOIDmode
1612 and that could cause a crash in reload. */
1613 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1616 /* ??? Can this happen, and does the error message make any sense? */
1617 if (TREE_PURPOSE (tail) == NULL_TREE)
1619 error ("hard register `%s' listed as input operand to `asm'",
1620 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1624 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1625 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1626 orig_constraint = constraint;
1628 /* Make sure constraint has neither `=', `+', nor '&'. */
1630 for (j = 0; j < c_len; j++)
1631 switch (constraint[j])
1633 case '+': case '=': case '&':
1634 if (constraint == orig_constraint)
1636 error ("input operand constraint contains `%c'",
1643 if (constraint == orig_constraint
1644 && i + 1 == ninputs - ninout)
1646 error ("`%%' constraint used with last operand");
1651 case 'V': case 'm': case 'o':
1656 case '?': case '!': case '*':
1657 case 'E': case 'F': case 'G': case 'H':
1658 case 's': case 'i': case 'n':
1659 case 'I': case 'J': case 'K': case 'L': case 'M':
1660 case 'N': case 'O': case 'P': case ',':
1663 /* Whether or not a numeric constraint allows a register is
1664 decided by the matching constraint, and so there is no need
1665 to do anything special with them. We must handle them in
1666 the default case, so that we don't unnecessarily force
1667 operands to memory. */
1668 case '0': case '1': case '2': case '3': case '4':
1669 case '5': case '6': case '7': case '8': case '9':
1670 if (constraint[j] >= '0' + noutputs)
1673 ("matching constraint references invalid operand number");
1677 /* Try and find the real constraint for this dup. */
1678 if ((j == 0 && c_len == 1)
1679 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1683 for (j = constraint[j] - '0'; j > 0; --j)
1686 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1687 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1704 if (! ISALPHA (constraint[j]))
1706 error ("invalid punctuation `%c' in constraint",
1710 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1712 #ifdef EXTRA_CONSTRAINT
1715 /* Otherwise we can't assume anything about the nature of
1716 the constraint except that it isn't purely registers.
1717 Treat it like "g" and hope for the best. */
1725 if (! allows_reg && allows_mem)
1726 mark_addressable (TREE_VALUE (tail));
1728 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1730 if (asm_operand_ok (op, constraint) <= 0)
1733 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1734 else if (!allows_mem)
1735 warning ("asm operand %d probably doesn't match constraints", i);
1736 else if (CONSTANT_P (op))
1737 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1739 else if (GET_CODE (op) == REG
1740 || GET_CODE (op) == SUBREG
1741 || GET_CODE (op) == CONCAT)
1743 tree type = TREE_TYPE (TREE_VALUE (tail));
1744 rtx memloc = assign_temp (type, 1, 1, 1);
1746 emit_move_insn (memloc, op);
1750 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1751 /* We won't recognize volatile memory as available a
1752 memory_operand at this point. Ignore it. */
1754 else if (queued_subexp_p (op))
1757 /* ??? Leave this only until we have experience with what
1758 happens in combine and elsewhere when constraints are
1760 warning ("asm operand %d probably doesn't match constraints", i);
1762 XVECEXP (body, 3, i) = op;
1764 XVECEXP (body, 4, i) /* constraints */
1765 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1770 /* Protect all the operands from the queue now that they have all been
1773 for (i = 0; i < ninputs - ninout; i++)
1774 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1776 for (i = 0; i < noutputs; i++)
1777 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1779 /* For in-out operands, copy output rtx to input rtx. */
1780 for (i = 0; i < ninout; i++)
1782 int j = inout_opnum[i];
1784 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1786 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1787 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1790 /* Now, for each output, construct an rtx
1791 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1792 ARGVEC CONSTRAINTS))
1793 If there is more than one, put them inside a PARALLEL. */
1795 if (noutputs == 1 && nclobbers == 0)
1797 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1798 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1801 else if (noutputs == 0 && nclobbers == 0)
1803 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1804 insn = emit_insn (body);
1815 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1817 /* For each output operand, store a SET. */
1818 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1820 XVECEXP (body, 0, i)
1821 = gen_rtx_SET (VOIDmode,
1823 gen_rtx_ASM_OPERANDS
1825 TREE_STRING_POINTER (string),
1826 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1827 i, argvec, constraints,
1830 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1833 /* If there are no outputs (but there are some clobbers)
1834 store the bare ASM_OPERANDS into the PARALLEL. */
1837 XVECEXP (body, 0, i++) = obody;
1839 /* Store (clobber REG) for each clobbered register specified. */
1841 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1843 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1844 int j = decode_reg_name (regname);
1848 if (j == -3) /* `cc', which is not a register */
1851 if (j == -4) /* `memory', don't cache memory across asm */
1853 XVECEXP (body, 0, i++)
1854 = gen_rtx_CLOBBER (VOIDmode,
1857 gen_rtx_SCRATCH (VOIDmode)));
1861 /* Ignore unknown register, error already signaled. */
1865 /* Use QImode since that's guaranteed to clobber just one reg. */
1866 XVECEXP (body, 0, i++)
1867 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1870 insn = emit_insn (body);
1873 /* For any outputs that needed reloading into registers, spill them
1874 back to where they belong. */
1875 for (i = 0; i < noutputs; ++i)
1876 if (real_output_rtx[i])
1877 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1882 /* Generate RTL to evaluate the expression EXP
1883 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1886 expand_expr_stmt (exp)
1889 /* If -W, warn about statements with no side effects,
1890 except for an explicit cast to void (e.g. for assert()), and
1891 except inside a ({...}) where they may be useful. */
1892 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1894 if (! TREE_SIDE_EFFECTS (exp)
1895 && (extra_warnings || warn_unused_value)
1896 && !(TREE_CODE (exp) == CONVERT_EXPR
1897 && VOID_TYPE_P (TREE_TYPE (exp))))
1898 warning_with_file_and_line (emit_filename, emit_lineno,
1899 "statement with no effect");
1900 else if (warn_unused_value)
1901 warn_if_unused_value (exp);
1904 /* If EXP is of function type and we are expanding statements for
1905 value, convert it to pointer-to-function. */
1906 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1907 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1909 last_expr_type = TREE_TYPE (exp);
1910 last_expr_value = expand_expr (exp,
1911 (expr_stmts_for_value
1912 ? NULL_RTX : const0_rtx),
1915 /* If all we do is reference a volatile value in memory,
1916 copy it to a register to be sure it is actually touched. */
1917 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1918 && TREE_THIS_VOLATILE (exp))
1920 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1922 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1923 copy_to_reg (last_expr_value);
1926 rtx lab = gen_label_rtx ();
1928 /* Compare the value with itself to reference it. */
1929 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1930 expand_expr (TYPE_SIZE (last_expr_type),
1931 NULL_RTX, VOIDmode, 0),
1933 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1939 /* If this expression is part of a ({...}) and is in memory, we may have
1940 to preserve temporaries. */
1941 preserve_temp_slots (last_expr_value);
1943 /* Free any temporaries used to evaluate this expression. Any temporary
1944 used as a result of this expression will already have been preserved
1951 /* Warn if EXP contains any computations whose results are not used.
1952 Return 1 if a warning is printed; 0 otherwise. */
1955 warn_if_unused_value (exp)
1958 if (TREE_USED (exp))
1961 switch (TREE_CODE (exp))
1963 case PREINCREMENT_EXPR:
1964 case POSTINCREMENT_EXPR:
1965 case PREDECREMENT_EXPR:
1966 case POSTDECREMENT_EXPR:
1971 case METHOD_CALL_EXPR:
1973 case TRY_CATCH_EXPR:
1974 case WITH_CLEANUP_EXPR:
1976 /* We don't warn about COND_EXPR because it may be a useful
1977 construct if either arm contains a side effect. */
1982 /* For a binding, warn if no side effect within it. */
1983 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1986 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1988 case TRUTH_ORIF_EXPR:
1989 case TRUTH_ANDIF_EXPR:
1990 /* In && or ||, warn if 2nd operand has no side effect. */
1991 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1994 if (TREE_NO_UNUSED_WARNING (exp))
1996 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1998 /* Let people do `(foo (), 0)' without a warning. */
1999 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2001 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2005 case NON_LVALUE_EXPR:
2006 /* Don't warn about values cast to void. */
2007 if (VOID_TYPE_P (TREE_TYPE (exp)))
2009 /* Don't warn about conversions not explicit in the user's program. */
2010 if (TREE_NO_UNUSED_WARNING (exp))
2012 /* Assignment to a cast usually results in a cast of a modify.
2013 Don't complain about that. There can be an arbitrary number of
2014 casts before the modify, so we must loop until we find the first
2015 non-cast expression and then test to see if that is a modify. */
2017 tree tem = TREE_OPERAND (exp, 0);
2019 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2020 tem = TREE_OPERAND (tem, 0);
2022 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2023 || TREE_CODE (tem) == CALL_EXPR)
2029 /* Don't warn about automatic dereferencing of references, since
2030 the user cannot control it. */
2031 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2032 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2036 /* Referencing a volatile value is a side effect, so don't warn. */
2038 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2039 && TREE_THIS_VOLATILE (exp))
2042 /* If this is an expression which has no operands, there is no value
2043 to be unused. There are no such language-independent codes,
2044 but front ends may define such. */
2045 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2046 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2050 warning_with_file_and_line (emit_filename, emit_lineno,
2051 "value computed is not used");
2056 /* Clear out the memory of the last expression evaluated. */
2064 /* Begin a statement which will return a value.
2065 Return the RTL_EXPR for this statement expr.
2066 The caller must save that value and pass it to expand_end_stmt_expr. */
2069 expand_start_stmt_expr ()
2074 /* Make the RTL_EXPR node temporary, not momentary,
2075 so that rtl_expr_chain doesn't become garbage. */
2076 momentary = suspend_momentary ();
2077 t = make_node (RTL_EXPR);
2078 resume_momentary (momentary);
2079 do_pending_stack_adjust ();
2080 start_sequence_for_rtl_expr (t);
2082 expr_stmts_for_value++;
2086 /* Restore the previous state at the end of a statement that returns a value.
2087 Returns a tree node representing the statement's value and the
2088 insns to compute the value.
2090 The nodes of that expression have been freed by now, so we cannot use them.
2091 But we don't want to do that anyway; the expression has already been
2092 evaluated and now we just want to use the value. So generate a RTL_EXPR
2093 with the proper type and RTL value.
2095 If the last substatement was not an expression,
2096 return something with type `void'. */
2099 expand_end_stmt_expr (t)
2104 if (last_expr_type == 0)
2106 last_expr_type = void_type_node;
2107 last_expr_value = const0_rtx;
2109 else if (last_expr_value == 0)
2110 /* There are some cases where this can happen, such as when the
2111 statement is void type. */
2112 last_expr_value = const0_rtx;
2113 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2114 /* Remove any possible QUEUED. */
2115 last_expr_value = protect_from_queue (last_expr_value, 0);
2119 TREE_TYPE (t) = last_expr_type;
2120 RTL_EXPR_RTL (t) = last_expr_value;
2121 RTL_EXPR_SEQUENCE (t) = get_insns ();
2123 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2127 /* Don't consider deleting this expr or containing exprs at tree level. */
2128 TREE_SIDE_EFFECTS (t) = 1;
2129 /* Propagate volatility of the actual RTL expr. */
2130 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2133 expr_stmts_for_value--;
2138 /* Generate RTL for the start of an if-then. COND is the expression
2139 whose truth should be tested.
2141 If EXITFLAG is nonzero, this conditional is visible to
2142 `exit_something'. */
2145 expand_start_cond (cond, exitflag)
2149 struct nesting *thiscond = ALLOC_NESTING ();
2151 /* Make an entry on cond_stack for the cond we are entering. */
2153 thiscond->next = cond_stack;
2154 thiscond->all = nesting_stack;
2155 thiscond->depth = ++nesting_depth;
2156 thiscond->data.cond.next_label = gen_label_rtx ();
2157 /* Before we encounter an `else', we don't need a separate exit label
2158 unless there are supposed to be exit statements
2159 to exit this conditional. */
2160 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2161 thiscond->data.cond.endif_label = thiscond->exit_label;
2162 cond_stack = thiscond;
2163 nesting_stack = thiscond;
2165 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2168 /* Generate RTL between then-clause and the elseif-clause
2169 of an if-then-elseif-.... */
2172 expand_start_elseif (cond)
2175 if (cond_stack->data.cond.endif_label == 0)
2176 cond_stack->data.cond.endif_label = gen_label_rtx ();
2177 emit_jump (cond_stack->data.cond.endif_label);
2178 emit_label (cond_stack->data.cond.next_label);
2179 cond_stack->data.cond.next_label = gen_label_rtx ();
2180 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2183 /* Generate RTL between the then-clause and the else-clause
2184 of an if-then-else. */
2187 expand_start_else ()
2189 if (cond_stack->data.cond.endif_label == 0)
2190 cond_stack->data.cond.endif_label = gen_label_rtx ();
2192 emit_jump (cond_stack->data.cond.endif_label);
2193 emit_label (cond_stack->data.cond.next_label);
2194 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2197 /* After calling expand_start_else, turn this "else" into an "else if"
2198 by providing another condition. */
2201 expand_elseif (cond)
2204 cond_stack->data.cond.next_label = gen_label_rtx ();
2205 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2208 /* Generate RTL for the end of an if-then.
2209 Pop the record for it off of cond_stack. */
2214 struct nesting *thiscond = cond_stack;
2216 do_pending_stack_adjust ();
2217 if (thiscond->data.cond.next_label)
2218 emit_label (thiscond->data.cond.next_label);
2219 if (thiscond->data.cond.endif_label)
2220 emit_label (thiscond->data.cond.endif_label);
2222 POPSTACK (cond_stack);
2226 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2227 loop should be exited by `exit_something'. This is a loop for which
2228 `expand_continue' will jump to the top of the loop.
2230 Make an entry on loop_stack to record the labels associated with
2234 expand_start_loop (exit_flag)
2237 register struct nesting *thisloop = ALLOC_NESTING ();
2239 /* Make an entry on loop_stack for the loop we are entering. */
2241 thisloop->next = loop_stack;
2242 thisloop->all = nesting_stack;
2243 thisloop->depth = ++nesting_depth;
2244 thisloop->data.loop.start_label = gen_label_rtx ();
2245 thisloop->data.loop.end_label = gen_label_rtx ();
2246 thisloop->data.loop.alt_end_label = 0;
2247 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2248 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2249 loop_stack = thisloop;
2250 nesting_stack = thisloop;
2252 do_pending_stack_adjust ();
2254 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2255 emit_label (thisloop->data.loop.start_label);
2260 /* Like expand_start_loop but for a loop where the continuation point
2261 (for expand_continue_loop) will be specified explicitly. */
2264 expand_start_loop_continue_elsewhere (exit_flag)
2267 struct nesting *thisloop = expand_start_loop (exit_flag);
2268 loop_stack->data.loop.continue_label = gen_label_rtx ();
2272 /* Specify the continuation point for a loop started with
2273 expand_start_loop_continue_elsewhere.
2274 Use this at the point in the code to which a continue statement
2278 expand_loop_continue_here ()
2280 do_pending_stack_adjust ();
2281 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2282 emit_label (loop_stack->data.loop.continue_label);
2285 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2286 Pop the block off of loop_stack. */
2291 rtx start_label = loop_stack->data.loop.start_label;
2292 rtx insn = get_last_insn ();
2293 int needs_end_jump = 1;
2295 /* Mark the continue-point at the top of the loop if none elsewhere. */
2296 if (start_label == loop_stack->data.loop.continue_label)
2297 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2299 do_pending_stack_adjust ();
2301 /* If optimizing, perhaps reorder the loop.
2302 First, try to use a condjump near the end.
2303 expand_exit_loop_if_false ends loops with unconditional jumps,
2306 if (test) goto label;
2308 goto loop_stack->data.loop.end_label
2312 If we find such a pattern, we can end the loop earlier. */
2315 && GET_CODE (insn) == CODE_LABEL
2316 && LABEL_NAME (insn) == NULL
2317 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2320 rtx jump = PREV_INSN (PREV_INSN (label));
2322 if (GET_CODE (jump) == JUMP_INSN
2323 && GET_CODE (PATTERN (jump)) == SET
2324 && SET_DEST (PATTERN (jump)) == pc_rtx
2325 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2326 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2327 == loop_stack->data.loop.end_label))
2331 /* The test might be complex and reference LABEL multiple times,
2332 like the loop in loop_iterations to set vtop. To handle this,
2334 insn = PREV_INSN (label);
2335 reorder_insns (label, label, start_label);
2337 for (prev = PREV_INSN (jump);; prev = PREV_INSN (prev))
2339 /* We ignore line number notes, but if we see any other note,
2340 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2341 NOTE_INSN_LOOP_*, we disable this optimization. */
2342 if (GET_CODE (prev) == NOTE)
2344 if (NOTE_LINE_NUMBER (prev) < 0)
2348 if (GET_CODE (prev) == CODE_LABEL)
2350 if (GET_CODE (prev) == JUMP_INSN)
2352 if (GET_CODE (PATTERN (prev)) == SET
2353 && SET_DEST (PATTERN (prev)) == pc_rtx
2354 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2355 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2357 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2359 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2361 emit_note_after (NOTE_INSN_LOOP_END, prev);
2370 /* If the loop starts with a loop exit, roll that to the end where
2371 it will optimize together with the jump back.
2373 We look for the conditional branch to the exit, except that once
2374 we find such a branch, we don't look past 30 instructions.
2376 In more detail, if the loop presently looks like this (in pseudo-C):
2379 if (test) goto end_label;
2384 transform it to look like:
2390 if (test) goto end_label;
2391 goto newstart_label;
2394 Here, the `test' may actually consist of some reasonably complex
2395 code, terminating in a test. */
2400 ! (GET_CODE (insn) == JUMP_INSN
2401 && GET_CODE (PATTERN (insn)) == SET
2402 && SET_DEST (PATTERN (insn)) == pc_rtx
2403 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2407 rtx last_test_insn = NULL_RTX;
2409 /* Scan insns from the top of the loop looking for a qualified
2410 conditional exit. */
2411 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2412 insn = NEXT_INSN (insn))
2414 if (GET_CODE (insn) == NOTE)
2417 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2418 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2419 /* The code that actually moves the exit test will
2420 carefully leave BLOCK notes in their original
2421 location. That means, however, that we can't debug
2422 the exit test itself. So, we refuse to move code
2423 containing BLOCK notes at low optimization levels. */
2426 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2428 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2432 /* We've come to the end of an EH region, but
2433 never saw the beginning of that region. That
2434 means that an EH region begins before the top
2435 of the loop, and ends in the middle of it. The
2436 existence of such a situation violates a basic
2437 assumption in this code, since that would imply
2438 that even when EH_REGIONS is zero, we might
2439 move code out of an exception region. */
2443 /* We must not walk into a nested loop. */
2444 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2447 /* We already know this INSN is a NOTE, so there's no
2448 point in looking at it to see if it's a JUMP. */
2452 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2455 if (last_test_insn && num_insns > 30)
2459 /* We don't want to move a partial EH region. Consider:
2473 This isn't legal C++, but here's what it's supposed to
2474 mean: if cond() is true, stop looping. Otherwise,
2475 call bar, and keep looping. In addition, if cond
2476 throws an exception, catch it and keep looping. Such
2477 constructs are certainy legal in LISP.
2479 We should not move the `if (cond()) 0' test since then
2480 the EH-region for the try-block would be broken up.
2481 (In this case we would the EH_BEG note for the `try'
2482 and `if cond()' but not the call to bar() or the
2485 So we don't look for tests within an EH region. */
2488 if (GET_CODE (insn) == JUMP_INSN
2489 && GET_CODE (PATTERN (insn)) == SET
2490 && SET_DEST (PATTERN (insn)) == pc_rtx)
2492 /* This is indeed a jump. */
2493 rtx dest1 = NULL_RTX;
2494 rtx dest2 = NULL_RTX;
2495 rtx potential_last_test;
2496 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2498 /* A conditional jump. */
2499 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2500 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2501 potential_last_test = insn;
2505 /* An unconditional jump. */
2506 dest1 = SET_SRC (PATTERN (insn));
2507 /* Include the BARRIER after the JUMP. */
2508 potential_last_test = NEXT_INSN (insn);
2512 if (dest1 && GET_CODE (dest1) == LABEL_REF
2513 && ((XEXP (dest1, 0)
2514 == loop_stack->data.loop.alt_end_label)
2516 == loop_stack->data.loop.end_label)))
2518 last_test_insn = potential_last_test;
2522 /* If this was a conditional jump, there may be
2523 another label at which we should look. */
2530 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2532 /* We found one. Move everything from there up
2533 to the end of the loop, and add a jump into the loop
2534 to jump to there. */
2535 register rtx newstart_label = gen_label_rtx ();
2536 register rtx start_move = start_label;
2539 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2540 then we want to move this note also. */
2541 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2542 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2543 == NOTE_INSN_LOOP_CONT))
2544 start_move = PREV_INSN (start_move);
2546 emit_label_after (newstart_label, PREV_INSN (start_move));
2548 /* Actually move the insns. Start at the beginning, and
2549 keep copying insns until we've copied the
2551 for (insn = start_move; insn; insn = next_insn)
2553 /* Figure out which insn comes after this one. We have
2554 to do this before we move INSN. */
2555 if (insn == last_test_insn)
2556 /* We've moved all the insns. */
2557 next_insn = NULL_RTX;
2559 next_insn = NEXT_INSN (insn);
2561 if (GET_CODE (insn) == NOTE
2562 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2563 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2564 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2565 NOTE_INSN_BLOCK_ENDs because the correct generation
2566 of debugging information depends on these appearing
2567 in the same order in the RTL and in the tree
2568 structure, where they are represented as BLOCKs.
2569 So, we don't move block notes. Of course, moving
2570 the code inside the block is likely to make it
2571 impossible to debug the instructions in the exit
2572 test, but such is the price of optimization. */
2575 /* Move the INSN. */
2576 reorder_insns (insn, insn, get_last_insn ());
2579 emit_jump_insn_after (gen_jump (start_label),
2580 PREV_INSN (newstart_label));
2581 emit_barrier_after (PREV_INSN (newstart_label));
2582 start_label = newstart_label;
2588 emit_jump (start_label);
2589 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2591 emit_label (loop_stack->data.loop.end_label);
2593 POPSTACK (loop_stack);
2598 /* Generate a jump to the current loop's continue-point.
2599 This is usually the top of the loop, but may be specified
2600 explicitly elsewhere. If not currently inside a loop,
2601 return 0 and do nothing; caller will print an error message. */
2604 expand_continue_loop (whichloop)
2605 struct nesting *whichloop;
2609 whichloop = loop_stack;
2612 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2617 /* Generate a jump to exit the current loop. If not currently inside a loop,
2618 return 0 and do nothing; caller will print an error message. */
2621 expand_exit_loop (whichloop)
2622 struct nesting *whichloop;
2626 whichloop = loop_stack;
2629 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2633 /* Generate a conditional jump to exit the current loop if COND
2634 evaluates to zero. If not currently inside a loop,
2635 return 0 and do nothing; caller will print an error message. */
2638 expand_exit_loop_if_false (whichloop, cond)
2639 struct nesting *whichloop;
2642 rtx label = gen_label_rtx ();
2647 whichloop = loop_stack;
2650 /* In order to handle fixups, we actually create a conditional jump
2651 around a unconditional branch to exit the loop. If fixups are
2652 necessary, they go before the unconditional branch. */
2654 do_jump (cond, NULL_RTX, label);
2655 last_insn = get_last_insn ();
2656 if (GET_CODE (last_insn) == CODE_LABEL)
2657 whichloop->data.loop.alt_end_label = last_insn;
2658 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2665 /* Return nonzero if the loop nest is empty. Else return zero. */
2668 stmt_loop_nest_empty ()
2670 /* cfun->stmt can be NULL if we are building a call to get the
2671 EH context for a setjmp/longjmp EH target and the current
2672 function was a deferred inline function. */
2673 return (cfun->stmt == NULL || loop_stack == NULL);
2676 /* Return non-zero if we should preserve sub-expressions as separate
2677 pseudos. We never do so if we aren't optimizing. We always do so
2678 if -fexpensive-optimizations.
2680 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2681 the loop may still be a small one. */
2684 preserve_subexpressions_p ()
2688 if (flag_expensive_optimizations)
2691 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2694 insn = get_last_insn_anywhere ();
2697 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2698 < n_non_fixed_regs * 3));
2702 /* Generate a jump to exit the current loop, conditional, binding contour
2703 or case statement. Not all such constructs are visible to this function,
2704 only those started with EXIT_FLAG nonzero. Individual languages use
2705 the EXIT_FLAG parameter to control which kinds of constructs you can
2708 If not currently inside anything that can be exited,
2709 return 0 and do nothing; caller will print an error message. */
2712 expand_exit_something ()
2716 for (n = nesting_stack; n; n = n->all)
2717 if (n->exit_label != 0)
2719 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2726 /* Generate RTL to return from the current function, with no value.
2727 (That is, we do not do anything about returning any value.) */
2730 expand_null_return ()
2732 struct nesting *block = block_stack;
2733 rtx last_insn = get_last_insn ();
2735 /* If this function was declared to return a value, but we
2736 didn't, clobber the return registers so that they are not
2737 propogated live to the rest of the function. */
2738 clobber_return_register ();
2740 /* Does any pending block have cleanups? */
2741 while (block && block->data.block.cleanups == 0)
2742 block = block->next;
2744 /* If yes, use a goto to return, since that runs cleanups. */
2746 expand_null_return_1 (last_insn, block != 0);
2749 /* Generate RTL to return from the current function, with value VAL. */
2752 expand_value_return (val)
2755 struct nesting *block = block_stack;
2756 rtx last_insn = get_last_insn ();
2757 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2759 /* Copy the value to the return location
2760 unless it's already there. */
2762 if (return_reg != val)
2764 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2765 #ifdef PROMOTE_FUNCTION_RETURN
2766 int unsignedp = TREE_UNSIGNED (type);
2767 enum machine_mode old_mode
2768 = DECL_MODE (DECL_RESULT (current_function_decl));
2769 enum machine_mode mode
2770 = promote_mode (type, old_mode, &unsignedp, 1);
2772 if (mode != old_mode)
2773 val = convert_modes (mode, old_mode, val, unsignedp);
2775 if (GET_CODE (return_reg) == PARALLEL)
2776 emit_group_load (return_reg, val, int_size_in_bytes (type),
2779 emit_move_insn (return_reg, val);
2782 /* Does any pending block have cleanups? */
2784 while (block && block->data.block.cleanups == 0)
2785 block = block->next;
2787 /* If yes, use a goto to return, since that runs cleanups.
2788 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2790 expand_null_return_1 (last_insn, block != 0);
2793 /* Output a return with no value. If LAST_INSN is nonzero,
2794 pretend that the return takes place after LAST_INSN.
2795 If USE_GOTO is nonzero then don't use a return instruction;
2796 go to the return label instead. This causes any cleanups
2797 of pending blocks to be executed normally. */
2800 expand_null_return_1 (last_insn, use_goto)
2804 rtx end_label = cleanup_label ? cleanup_label : return_label;
2806 clear_pending_stack_adjust ();
2807 do_pending_stack_adjust ();
2810 /* PCC-struct return always uses an epilogue. */
2811 if (current_function_returns_pcc_struct || use_goto)
2814 end_label = return_label = gen_label_rtx ();
2815 expand_goto_internal (NULL_TREE, end_label, last_insn);
2819 /* Otherwise output a simple return-insn if one is available,
2820 unless it won't do the job. */
2822 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2824 emit_jump_insn (gen_return ());
2830 /* Otherwise jump to the epilogue. */
2831 expand_goto_internal (NULL_TREE, end_label, last_insn);
2834 /* Generate RTL to evaluate the expression RETVAL and return it
2835 from the current function. */
2838 expand_return (retval)
2841 /* If there are any cleanups to be performed, then they will
2842 be inserted following LAST_INSN. It is desirable
2843 that the last_insn, for such purposes, should be the
2844 last insn before computing the return value. Otherwise, cleanups
2845 which call functions can clobber the return value. */
2846 /* ??? rms: I think that is erroneous, because in C++ it would
2847 run destructors on variables that might be used in the subsequent
2848 computation of the return value. */
2850 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2851 register rtx val = 0;
2855 /* If function wants no value, give it none. */
2856 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2858 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2860 expand_null_return ();
2864 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2865 /* This is not sufficient. We also need to watch for cleanups of the
2866 expression we are about to expand. Unfortunately, we cannot know
2867 if it has cleanups until we expand it, and we want to change how we
2868 expand it depending upon if we need cleanups. We can't win. */
2870 cleanups = any_pending_cleanups (1);
2875 if (retval == error_mark_node)
2876 retval_rhs = NULL_TREE;
2877 else if (TREE_CODE (retval) == RESULT_DECL)
2878 retval_rhs = retval;
2879 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2880 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2881 retval_rhs = TREE_OPERAND (retval, 1);
2882 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2883 /* Recognize tail-recursive call to void function. */
2884 retval_rhs = retval;
2886 retval_rhs = NULL_TREE;
2888 /* Only use `last_insn' if there are cleanups which must be run. */
2889 if (cleanups || cleanup_label != 0)
2890 last_insn = get_last_insn ();
2892 /* Distribute return down conditional expr if either of the sides
2893 may involve tail recursion (see test below). This enhances the number
2894 of tail recursions we see. Don't do this always since it can produce
2895 sub-optimal code in some cases and we distribute assignments into
2896 conditional expressions when it would help. */
2898 if (optimize && retval_rhs != 0
2899 && frame_offset == 0
2900 && TREE_CODE (retval_rhs) == COND_EXPR
2901 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2902 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2904 rtx label = gen_label_rtx ();
2907 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2908 start_cleanup_deferral ();
2909 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2910 DECL_RESULT (current_function_decl),
2911 TREE_OPERAND (retval_rhs, 1));
2912 TREE_SIDE_EFFECTS (expr) = 1;
2913 expand_return (expr);
2916 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2917 DECL_RESULT (current_function_decl),
2918 TREE_OPERAND (retval_rhs, 2));
2919 TREE_SIDE_EFFECTS (expr) = 1;
2920 expand_return (expr);
2921 end_cleanup_deferral ();
2925 /* If the result is an aggregate that is being returned in one (or more)
2926 registers, load the registers here. The compiler currently can't handle
2927 copying a BLKmode value into registers. We could put this code in a
2928 more general area (for use by everyone instead of just function
2929 call/return), but until this feature is generally usable it is kept here
2930 (and in expand_call). The value must go into a pseudo in case there
2931 are cleanups that will clobber the real return register. */
2934 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2935 && GET_CODE (result_rtl) == REG)
2938 unsigned HOST_WIDE_INT bitpos, xbitpos;
2939 unsigned HOST_WIDE_INT big_endian_correction = 0;
2940 unsigned HOST_WIDE_INT bytes
2941 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2942 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2943 unsigned int bitsize
2944 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2945 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2946 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2947 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2948 enum machine_mode tmpmode, result_reg_mode;
2950 /* Structures whose size is not a multiple of a word are aligned
2951 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2952 machine, this means we must skip the empty high order bytes when
2953 calculating the bit offset. */
2954 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2955 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2958 /* Copy the structure BITSIZE bits at a time. */
2959 for (bitpos = 0, xbitpos = big_endian_correction;
2960 bitpos < bytes * BITS_PER_UNIT;
2961 bitpos += bitsize, xbitpos += bitsize)
2963 /* We need a new destination pseudo each time xbitpos is
2964 on a word boundary and when xbitpos == big_endian_correction
2965 (the first time through). */
2966 if (xbitpos % BITS_PER_WORD == 0
2967 || xbitpos == big_endian_correction)
2969 /* Generate an appropriate register. */
2970 dst = gen_reg_rtx (word_mode);
2971 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2973 /* Clobber the destination before we move anything into it. */
2974 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2977 /* We need a new source operand each time bitpos is on a word
2979 if (bitpos % BITS_PER_WORD == 0)
2980 src = operand_subword_force (result_val,
2981 bitpos / BITS_PER_WORD,
2984 /* Use bitpos for the source extraction (left justified) and
2985 xbitpos for the destination store (right justified). */
2986 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2987 extract_bit_field (src, bitsize,
2988 bitpos % BITS_PER_WORD, 1,
2989 NULL_RTX, word_mode, word_mode,
2990 bitsize, BITS_PER_WORD),
2991 bitsize, BITS_PER_WORD);
2994 /* Find the smallest integer mode large enough to hold the
2995 entire structure and use that mode instead of BLKmode
2996 on the USE insn for the return register. */
2997 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2998 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2999 tmpmode != VOIDmode;
3000 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3002 /* Have we found a large enough mode? */
3003 if (GET_MODE_SIZE (tmpmode) >= bytes)
3007 /* No suitable mode found. */
3008 if (tmpmode == VOIDmode)
3011 PUT_MODE (result_rtl, tmpmode);
3013 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3014 result_reg_mode = word_mode;
3016 result_reg_mode = tmpmode;
3017 result_reg = gen_reg_rtx (result_reg_mode);
3020 for (i = 0; i < n_regs; i++)
3021 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3024 if (tmpmode != result_reg_mode)
3025 result_reg = gen_lowpart (tmpmode, result_reg);
3027 expand_value_return (result_reg);
3031 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3032 && (GET_CODE (result_rtl) == REG
3033 || (GET_CODE (result_rtl) == PARALLEL)))
3035 /* Calculate the return value into a temporary (usually a pseudo
3037 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3039 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3040 val = force_not_mem (val);
3042 /* Return the calculated value, doing cleanups first. */
3043 expand_value_return (val);
3047 /* No cleanups or no hard reg used;
3048 calculate value into hard return reg. */
3049 expand_expr (retval, const0_rtx, VOIDmode, 0);
3051 expand_value_return (result_rtl);
3055 /* Return 1 if the end of the generated RTX is not a barrier.
3056 This means code already compiled can drop through. */
3059 drop_through_at_end_p ()
3061 rtx insn = get_last_insn ();
3062 while (insn && GET_CODE (insn) == NOTE)
3063 insn = PREV_INSN (insn);
3064 return insn && GET_CODE (insn) != BARRIER;
3067 /* Attempt to optimize a potential tail recursion call into a goto.
3068 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3069 where to place the jump to the tail recursion label.
3071 Return TRUE if the call was optimized into a goto. */
3074 optimize_tail_recursion (arguments, last_insn)
3078 /* Finish checking validity, and if valid emit code to set the
3079 argument variables for the new call. */
3080 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3082 if (tail_recursion_label == 0)
3084 tail_recursion_label = gen_label_rtx ();
3085 emit_label_after (tail_recursion_label,
3086 tail_recursion_reentry);
3089 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3096 /* Emit code to alter this function's formal parms for a tail-recursive call.
3097 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3098 FORMALS is the chain of decls of formals.
3099 Return 1 if this can be done;
3100 otherwise return 0 and do not emit any code. */
3103 tail_recursion_args (actuals, formals)
3104 tree actuals, formals;
3106 register tree a = actuals, f = formals;
3108 register rtx *argvec;
3110 /* Check that number and types of actuals are compatible
3111 with the formals. This is not always true in valid C code.
3112 Also check that no formal needs to be addressable
3113 and that all formals are scalars. */
3115 /* Also count the args. */
3117 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3119 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3120 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3122 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3125 if (a != 0 || f != 0)
3128 /* Compute all the actuals. */
3130 argvec = (rtx *) alloca (i * sizeof (rtx));
3132 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3133 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3135 /* Find which actual values refer to current values of previous formals.
3136 Copy each of them now, before any formal is changed. */
3138 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3142 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3143 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3149 argvec[i] = copy_to_reg (argvec[i]);
3152 /* Store the values of the actuals into the formals. */
3154 for (f = formals, a = actuals, i = 0; f;
3155 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3157 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3158 emit_move_insn (DECL_RTL (f), argvec[i]);
3160 convert_move (DECL_RTL (f), argvec[i],
3161 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3168 /* Generate the RTL code for entering a binding contour.
3169 The variables are declared one by one, by calls to `expand_decl'.
3171 FLAGS is a bitwise or of the following flags:
3173 1 - Nonzero if this construct should be visible to
3176 2 - Nonzero if this contour does not require a
3177 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3178 language-independent code should set this flag because they
3179 will not create corresponding BLOCK nodes. (There should be
3180 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3181 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3182 when expand_end_bindings is called.
3184 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3185 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3189 expand_start_bindings_and_block (flags, block)
3193 struct nesting *thisblock = ALLOC_NESTING ();
3195 int exit_flag = ((flags & 1) != 0);
3196 int block_flag = ((flags & 2) == 0);
3198 /* If a BLOCK is supplied, then the caller should be requesting a
3199 NOTE_INSN_BLOCK_BEG note. */
3200 if (!block_flag && block)
3203 /* Create a note to mark the beginning of the block. */
3206 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3207 NOTE_BLOCK (note) = block;
3210 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3212 /* Make an entry on block_stack for the block we are entering. */
3214 thisblock->next = block_stack;
3215 thisblock->all = nesting_stack;
3216 thisblock->depth = ++nesting_depth;
3217 thisblock->data.block.stack_level = 0;
3218 thisblock->data.block.cleanups = 0;
3219 thisblock->data.block.n_function_calls = 0;
3220 thisblock->data.block.exception_region = 0;
3221 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3223 thisblock->data.block.conditional_code = 0;
3224 thisblock->data.block.last_unconditional_cleanup = note;
3225 /* When we insert instructions after the last unconditional cleanup,
3226 we don't adjust last_insn. That means that a later add_insn will
3227 clobber the instructions we've just added. The easiest way to
3228 fix this is to just insert another instruction here, so that the
3229 instructions inserted after the last unconditional cleanup are
3230 never the last instruction. */
3231 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3232 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3235 && !(block_stack->data.block.cleanups == NULL_TREE
3236 && block_stack->data.block.outer_cleanups == NULL_TREE))
3237 thisblock->data.block.outer_cleanups
3238 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3239 block_stack->data.block.outer_cleanups);
3241 thisblock->data.block.outer_cleanups = 0;
3242 thisblock->data.block.label_chain = 0;
3243 thisblock->data.block.innermost_stack_block = stack_block_stack;
3244 thisblock->data.block.first_insn = note;
3245 thisblock->data.block.block_start_count = ++current_block_start_count;
3246 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3247 block_stack = thisblock;
3248 nesting_stack = thisblock;
3250 /* Make a new level for allocating stack slots. */
3254 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3255 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3256 expand_expr are made. After we end the region, we know that all
3257 space for all temporaries that were created by TARGET_EXPRs will be
3258 destroyed and their space freed for reuse. */
3261 expand_start_target_temps ()
3263 /* This is so that even if the result is preserved, the space
3264 allocated will be freed, as we know that it is no longer in use. */
3267 /* Start a new binding layer that will keep track of all cleanup
3268 actions to be performed. */
3269 expand_start_bindings (2);
3271 target_temp_slot_level = temp_slot_level;
3275 expand_end_target_temps ()
3277 expand_end_bindings (NULL_TREE, 0, 0);
3279 /* This is so that even if the result is preserved, the space
3280 allocated will be freed, as we know that it is no longer in use. */
3284 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3285 in question represents the outermost pair of curly braces (i.e. the "body
3286 block") of a function or method.
3288 For any BLOCK node representing a "body block" of a function or method, the
3289 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3290 represents the outermost (function) scope for the function or method (i.e.
3291 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3292 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3295 is_body_block (stmt)
3298 if (TREE_CODE (stmt) == BLOCK)
3300 tree parent = BLOCK_SUPERCONTEXT (stmt);
3302 if (parent && TREE_CODE (parent) == BLOCK)
3304 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3306 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3314 /* Mark top block of block_stack as an implicit binding for an
3315 exception region. This is used to prevent infinite recursion when
3316 ending a binding with expand_end_bindings. It is only ever called
3317 by expand_eh_region_start, as that it the only way to create a
3318 block stack for a exception region. */
3321 mark_block_as_eh_region ()
3323 block_stack->data.block.exception_region = 1;
3324 if (block_stack->next
3325 && block_stack->next->data.block.conditional_code)
3327 block_stack->data.block.conditional_code
3328 = block_stack->next->data.block.conditional_code;
3329 block_stack->data.block.last_unconditional_cleanup
3330 = block_stack->next->data.block.last_unconditional_cleanup;
3331 block_stack->data.block.cleanup_ptr
3332 = block_stack->next->data.block.cleanup_ptr;
3336 /* True if we are currently emitting insns in an area of output code
3337 that is controlled by a conditional expression. This is used by
3338 the cleanup handling code to generate conditional cleanup actions. */
3341 conditional_context ()
3343 return block_stack && block_stack->data.block.conditional_code;
3346 /* Mark top block of block_stack as not for an implicit binding for an
3347 exception region. This is only ever done by expand_eh_region_end
3348 to let expand_end_bindings know that it is being called explicitly
3349 to end the binding layer for just the binding layer associated with
3350 the exception region, otherwise expand_end_bindings would try and
3351 end all implicit binding layers for exceptions regions, and then
3352 one normal binding layer. */
3355 mark_block_as_not_eh_region ()
3357 block_stack->data.block.exception_region = 0;
3360 /* True if the top block of block_stack was marked as for an exception
3361 region by mark_block_as_eh_region. */
3366 return cfun && block_stack && block_stack->data.block.exception_region;
3369 /* Emit a handler label for a nonlocal goto handler.
3370 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3373 expand_nl_handler_label (slot, before_insn)
3374 rtx slot, before_insn;
3377 rtx handler_label = gen_label_rtx ();
3379 /* Don't let jump_optimize delete the handler. */
3380 LABEL_PRESERVE_P (handler_label) = 1;
3383 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3384 insns = get_insns ();
3386 emit_insns_before (insns, before_insn);
3388 emit_label (handler_label);
3390 return handler_label;
3393 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3396 expand_nl_goto_receiver ()
3398 #ifdef HAVE_nonlocal_goto
3399 if (! HAVE_nonlocal_goto)
3401 /* First adjust our frame pointer to its actual value. It was
3402 previously set to the start of the virtual area corresponding to
3403 the stacked variables when we branched here and now needs to be
3404 adjusted to the actual hardware fp value.
3406 Assignments are to virtual registers are converted by
3407 instantiate_virtual_regs into the corresponding assignment
3408 to the underlying register (fp in this case) that makes
3409 the original assignment true.
3410 So the following insn will actually be
3411 decrementing fp by STARTING_FRAME_OFFSET. */
3412 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3414 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3415 if (fixed_regs[ARG_POINTER_REGNUM])
3417 #ifdef ELIMINABLE_REGS
3418 /* If the argument pointer can be eliminated in favor of the
3419 frame pointer, we don't need to restore it. We assume here
3420 that if such an elimination is present, it can always be used.
3421 This is the case on all known machines; if we don't make this
3422 assumption, we do unnecessary saving on many machines. */
3423 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3426 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3427 if (elim_regs[i].from == ARG_POINTER_REGNUM
3428 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3431 if (i == ARRAY_SIZE (elim_regs))
3434 /* Now restore our arg pointer from the address at which it
3435 was saved in our stack frame.
3436 If there hasn't be space allocated for it yet, make
3438 if (arg_pointer_save_area == 0)
3439 arg_pointer_save_area
3440 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3441 emit_move_insn (virtual_incoming_args_rtx,
3442 /* We need a pseudo here, or else
3443 instantiate_virtual_regs_1 complains. */
3444 copy_to_reg (arg_pointer_save_area));
3449 #ifdef HAVE_nonlocal_goto_receiver
3450 if (HAVE_nonlocal_goto_receiver)
3451 emit_insn (gen_nonlocal_goto_receiver ());
3455 /* Make handlers for nonlocal gotos taking place in the function calls in
3459 expand_nl_goto_receivers (thisblock)
3460 struct nesting *thisblock;
3463 rtx afterward = gen_label_rtx ();
3468 /* Record the handler address in the stack slot for that purpose,
3469 during this block, saving and restoring the outer value. */
3470 if (thisblock->next != 0)
3471 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3473 rtx save_receiver = gen_reg_rtx (Pmode);
3474 emit_move_insn (XEXP (slot, 0), save_receiver);
3477 emit_move_insn (save_receiver, XEXP (slot, 0));
3478 insns = get_insns ();
3480 emit_insns_before (insns, thisblock->data.block.first_insn);
3483 /* Jump around the handlers; they run only when specially invoked. */
3484 emit_jump (afterward);
3486 /* Make a separate handler for each label. */
3487 link = nonlocal_labels;
3488 slot = nonlocal_goto_handler_slots;
3489 label_list = NULL_RTX;
3490 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3491 /* Skip any labels we shouldn't be able to jump to from here,
3492 we generate one special handler for all of them below which just calls
3494 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3497 lab = expand_nl_handler_label (XEXP (slot, 0),
3498 thisblock->data.block.first_insn);
3499 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3501 expand_nl_goto_receiver ();
3503 /* Jump to the "real" nonlocal label. */
3504 expand_goto (TREE_VALUE (link));
3507 /* A second pass over all nonlocal labels; this time we handle those
3508 we should not be able to jump to at this point. */
3509 link = nonlocal_labels;
3510 slot = nonlocal_goto_handler_slots;
3512 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3513 if (DECL_TOO_LATE (TREE_VALUE (link)))
3516 lab = expand_nl_handler_label (XEXP (slot, 0),
3517 thisblock->data.block.first_insn);
3518 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3524 expand_nl_goto_receiver ();
3525 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3530 nonlocal_goto_handler_labels = label_list;
3531 emit_label (afterward);
3534 /* Warn about any unused VARS (which may contain nodes other than
3535 VAR_DECLs, but such nodes are ignored). The nodes are connected
3536 via the TREE_CHAIN field. */
3539 warn_about_unused_variables (vars)
3544 if (warn_unused_variable)
3545 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3546 if (TREE_CODE (decl) == VAR_DECL
3547 && ! TREE_USED (decl)
3548 && ! DECL_IN_SYSTEM_HEADER (decl)
3549 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3550 warning_with_decl (decl, "unused variable `%s'");
3553 /* Generate RTL code to terminate a binding contour.
3555 VARS is the chain of VAR_DECL nodes for the variables bound in this
3556 contour. There may actually be other nodes in this chain, but any
3557 nodes other than VAR_DECLS are ignored.
3559 MARK_ENDS is nonzero if we should put a note at the beginning
3560 and end of this binding contour.
3562 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3563 (That is true automatically if the contour has a saved stack level.) */
3566 expand_end_bindings (vars, mark_ends, dont_jump_in)
3571 register struct nesting *thisblock;
3573 while (block_stack->data.block.exception_region)
3575 /* Because we don't need or want a new temporary level and
3576 because we didn't create one in expand_eh_region_start,
3577 create a fake one now to avoid removing one in
3578 expand_end_bindings. */
3581 block_stack->data.block.exception_region = 0;
3583 expand_end_bindings (NULL_TREE, 0, 0);
3586 /* Since expand_eh_region_start does an expand_start_bindings, we
3587 have to first end all the bindings that were created by
3588 expand_eh_region_start. */
3590 thisblock = block_stack;
3592 /* If any of the variables in this scope were not used, warn the
3594 warn_about_unused_variables (vars);
3596 if (thisblock->exit_label)
3598 do_pending_stack_adjust ();
3599 emit_label (thisblock->exit_label);
3602 /* If necessary, make handlers for nonlocal gotos taking
3603 place in the function calls in this block. */
3604 if (function_call_count != thisblock->data.block.n_function_calls
3606 /* Make handler for outermost block
3607 if there were any nonlocal gotos to this function. */
3608 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3609 /* Make handler for inner block if it has something
3610 special to do when you jump out of it. */
3611 : (thisblock->data.block.cleanups != 0
3612 || thisblock->data.block.stack_level != 0)))
3613 expand_nl_goto_receivers (thisblock);
3615 /* Don't allow jumping into a block that has a stack level.
3616 Cleanups are allowed, though. */
3618 || thisblock->data.block.stack_level != 0)
3620 struct label_chain *chain;
3622 /* Any labels in this block are no longer valid to go to.
3623 Mark them to cause an error message. */
3624 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3626 DECL_TOO_LATE (chain->label) = 1;
3627 /* If any goto without a fixup came to this label,
3628 that must be an error, because gotos without fixups
3629 come from outside all saved stack-levels. */
3630 if (TREE_ADDRESSABLE (chain->label))
3631 error_with_decl (chain->label,
3632 "label `%s' used before containing binding contour");
3636 /* Restore stack level in effect before the block
3637 (only if variable-size objects allocated). */
3638 /* Perform any cleanups associated with the block. */
3640 if (thisblock->data.block.stack_level != 0
3641 || thisblock->data.block.cleanups != 0)
3646 /* Don't let cleanups affect ({...}) constructs. */
3647 int old_expr_stmts_for_value = expr_stmts_for_value;
3648 rtx old_last_expr_value = last_expr_value;
3649 tree old_last_expr_type = last_expr_type;
3650 expr_stmts_for_value = 0;
3652 /* Only clean up here if this point can actually be reached. */
3653 insn = get_last_insn ();
3654 if (GET_CODE (insn) == NOTE)
3655 insn = prev_nonnote_insn (insn);
3656 reachable = (! insn || GET_CODE (insn) != BARRIER);
3658 /* Do the cleanups. */
3659 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3661 do_pending_stack_adjust ();
3663 expr_stmts_for_value = old_expr_stmts_for_value;
3664 last_expr_value = old_last_expr_value;
3665 last_expr_type = old_last_expr_type;
3667 /* Restore the stack level. */
3669 if (reachable && thisblock->data.block.stack_level != 0)
3671 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3672 thisblock->data.block.stack_level, NULL_RTX);
3673 if (nonlocal_goto_handler_slots != 0)
3674 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3678 /* Any gotos out of this block must also do these things.
3679 Also report any gotos with fixups that came to labels in this
3681 fixup_gotos (thisblock,
3682 thisblock->data.block.stack_level,
3683 thisblock->data.block.cleanups,
3684 thisblock->data.block.first_insn,
3688 /* Mark the beginning and end of the scope if requested.
3689 We do this now, after running cleanups on the variables
3690 just going out of scope, so they are in scope for their cleanups. */
3694 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3695 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3698 /* Get rid of the beginning-mark if we don't make an end-mark. */
3699 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3701 /* Restore the temporary level of TARGET_EXPRs. */
3702 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3704 /* Restore block_stack level for containing block. */
3706 stack_block_stack = thisblock->data.block.innermost_stack_block;
3707 POPSTACK (block_stack);
3709 /* Pop the stack slot nesting and free any slots at this level. */
3713 /* Generate code to save the stack pointer at the start of the current block
3714 and set up to restore it on exit. */
3717 save_stack_pointer ()
3719 struct nesting *thisblock = block_stack;
3721 if (thisblock->data.block.stack_level == 0)
3723 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3724 &thisblock->data.block.stack_level,
3725 thisblock->data.block.first_insn);
3726 stack_block_stack = thisblock;
3730 /* Generate RTL for the automatic variable declaration DECL.
3731 (Other kinds of declarations are simply ignored if seen here.) */
3737 struct nesting *thisblock;
3740 type = TREE_TYPE (decl);
3742 /* Only automatic variables need any expansion done.
3743 Static and external variables, and external functions,
3744 will be handled by `assemble_variable' (called from finish_decl).
3745 TYPE_DECL and CONST_DECL require nothing.
3746 PARM_DECLs are handled in `assign_parms'. */
3748 if (TREE_CODE (decl) != VAR_DECL)
3750 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3753 thisblock = block_stack;
3755 /* Create the RTL representation for the variable. */
3757 if (type == error_mark_node)
3758 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3759 else if (DECL_SIZE (decl) == 0)
3760 /* Variable with incomplete type. */
3762 if (DECL_INITIAL (decl) == 0)
3763 /* Error message was already done; now avoid a crash. */
3764 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3766 /* An initializer is going to decide the size of this array.
3767 Until we know the size, represent its address with a reg. */
3768 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3770 set_mem_attributes (DECL_RTL (decl), decl, 1);
3772 else if (DECL_MODE (decl) != BLKmode
3773 /* If -ffloat-store, don't put explicit float vars
3775 && !(flag_float_store
3776 && TREE_CODE (type) == REAL_TYPE)
3777 && ! TREE_THIS_VOLATILE (decl)
3778 && ! TREE_ADDRESSABLE (decl)
3779 && (DECL_REGISTER (decl) || optimize)
3780 /* if -fcheck-memory-usage, check all variables. */
3781 && ! current_function_check_memory_usage)
3783 /* Automatic variable that can go in a register. */
3784 int unsignedp = TREE_UNSIGNED (type);
3785 enum machine_mode reg_mode
3786 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3788 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3789 mark_user_reg (DECL_RTL (decl));
3791 if (POINTER_TYPE_P (type))
3792 mark_reg_pointer (DECL_RTL (decl),
3793 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3795 maybe_set_unchanging (DECL_RTL (decl), decl);
3798 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3799 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3800 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3801 STACK_CHECK_MAX_VAR_SIZE)))
3803 /* Variable of fixed size that goes on the stack. */
3807 /* If we previously made RTL for this decl, it must be an array
3808 whose size was determined by the initializer.
3809 The old address was a register; set that register now
3810 to the proper address. */
3811 if (DECL_RTL (decl) != 0)
3813 if (GET_CODE (DECL_RTL (decl)) != MEM
3814 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3816 oldaddr = XEXP (DECL_RTL (decl), 0);
3819 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3821 /* Set alignment we actually gave this decl. */
3822 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3823 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3824 DECL_USER_ALIGN (decl) = 0;
3828 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3829 if (addr != oldaddr)
3830 emit_move_insn (oldaddr, addr);
3834 /* Dynamic-size object: must push space on the stack. */
3838 /* Record the stack pointer on entry to block, if have
3839 not already done so. */
3840 do_pending_stack_adjust ();
3841 save_stack_pointer ();
3843 /* In function-at-a-time mode, variable_size doesn't expand this,
3845 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3846 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3847 const0_rtx, VOIDmode, 0);
3849 /* Compute the variable's size, in bytes. */
3850 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3853 /* Allocate space on the stack for the variable. Note that
3854 DECL_ALIGN says how the variable is to be aligned and we
3855 cannot use it to conclude anything about the alignment of
3857 address = allocate_dynamic_stack_space (size, NULL_RTX,
3858 TYPE_ALIGN (TREE_TYPE (decl)));
3860 /* Reference the variable indirect through that rtx. */
3861 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3863 set_mem_attributes (DECL_RTL (decl), decl, 1);
3865 /* Indicate the alignment we actually gave this variable. */
3866 #ifdef STACK_BOUNDARY
3867 DECL_ALIGN (decl) = STACK_BOUNDARY;
3869 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3871 DECL_USER_ALIGN (decl) = 0;
3875 /* Emit code to perform the initialization of a declaration DECL. */
3878 expand_decl_init (decl)
3881 int was_used = TREE_USED (decl);
3883 /* If this is a CONST_DECL, we don't have to generate any code, but
3884 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3885 to be set while in the obstack containing the constant. If we don't
3886 do this, we can lose if we have functions nested three deep and the middle
3887 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3888 the innermost function is the first to expand that STRING_CST. */
3889 if (TREE_CODE (decl) == CONST_DECL)
3891 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3892 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3893 EXPAND_INITIALIZER);
3897 if (TREE_STATIC (decl))
3900 /* Compute and store the initial value now. */
3902 if (DECL_INITIAL (decl) == error_mark_node)
3904 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3906 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3907 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3908 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3912 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3914 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3915 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3919 /* Don't let the initialization count as "using" the variable. */
3920 TREE_USED (decl) = was_used;
3922 /* Free any temporaries we made while initializing the decl. */
3923 preserve_temp_slots (NULL_RTX);
3927 /* CLEANUP is an expression to be executed at exit from this binding contour;
3928 for example, in C++, it might call the destructor for this variable.
3930 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3931 CLEANUP multiple times, and have the correct semantics. This
3932 happens in exception handling, for gotos, returns, breaks that
3933 leave the current scope.
3935 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3936 that is not associated with any particular variable. */
3939 expand_decl_cleanup (decl, cleanup)
3942 struct nesting *thisblock;
3944 /* Error if we are not in any block. */
3945 if (cfun == 0 || block_stack == 0)
3948 thisblock = block_stack;
3950 /* Record the cleanup if there is one. */
3956 tree *cleanups = &thisblock->data.block.cleanups;
3957 int cond_context = conditional_context ();
3961 rtx flag = gen_reg_rtx (word_mode);
3966 emit_move_insn (flag, const0_rtx);
3967 set_flag_0 = get_insns ();
3970 thisblock->data.block.last_unconditional_cleanup
3971 = emit_insns_after (set_flag_0,
3972 thisblock->data.block.last_unconditional_cleanup);
3974 emit_move_insn (flag, const1_rtx);
3976 /* All cleanups must be on the function_obstack. */
3977 push_obstacks_nochange ();
3978 resume_temporary_allocation ();
3980 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3981 DECL_RTL (cond) = flag;
3983 /* Conditionalize the cleanup. */
3984 cleanup = build (COND_EXPR, void_type_node,
3985 truthvalue_conversion (cond),
3986 cleanup, integer_zero_node);
3987 cleanup = fold (cleanup);
3991 cleanups = thisblock->data.block.cleanup_ptr;
3994 /* All cleanups must be on the function_obstack. */
3995 push_obstacks_nochange ();
3996 resume_temporary_allocation ();
3997 cleanup = unsave_expr (cleanup);
4000 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4003 /* If this block has a cleanup, it belongs in stack_block_stack. */
4004 stack_block_stack = thisblock;
4011 /* If this was optimized so that there is no exception region for the
4012 cleanup, then mark the TREE_LIST node, so that we can later tell
4013 if we need to call expand_eh_region_end. */
4014 if (! using_eh_for_cleanups_p
4015 || expand_eh_region_start_tree (decl, cleanup))
4016 TREE_ADDRESSABLE (t) = 1;
4017 /* If that started a new EH region, we're in a new block. */
4018 thisblock = block_stack;
4025 thisblock->data.block.last_unconditional_cleanup
4026 = emit_insns_after (seq,
4027 thisblock->data.block.last_unconditional_cleanup);
4031 thisblock->data.block.last_unconditional_cleanup
4033 /* When we insert instructions after the last unconditional cleanup,
4034 we don't adjust last_insn. That means that a later add_insn will
4035 clobber the instructions we've just added. The easiest way to
4036 fix this is to just insert another instruction here, so that the
4037 instructions inserted after the last unconditional cleanup are
4038 never the last instruction. */
4039 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4040 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4046 /* Like expand_decl_cleanup, but suppress generating an exception handler
4047 to perform the cleanup. */
4051 expand_decl_cleanup_no_eh (decl, cleanup)
4054 int save_eh = using_eh_for_cleanups_p;
4057 using_eh_for_cleanups_p = 0;
4058 result = expand_decl_cleanup (decl, cleanup);
4059 using_eh_for_cleanups_p = save_eh;
4065 /* Arrange for the top element of the dynamic cleanup chain to be
4066 popped if we exit the current binding contour. DECL is the
4067 associated declaration, if any, otherwise NULL_TREE. If the
4068 current contour is left via an exception, then __sjthrow will pop
4069 the top element off the dynamic cleanup chain. The code that
4070 avoids doing the action we push into the cleanup chain in the
4071 exceptional case is contained in expand_cleanups.
4073 This routine is only used by expand_eh_region_start, and that is
4074 the only way in which an exception region should be started. This
4075 routine is only used when using the setjmp/longjmp codegen method
4076 for exception handling. */
4079 expand_dcc_cleanup (decl)
4082 struct nesting *thisblock;
4085 /* Error if we are not in any block. */
4086 if (cfun == 0 || block_stack == 0)
4088 thisblock = block_stack;
4090 /* Record the cleanup for the dynamic handler chain. */
4092 /* All cleanups must be on the function_obstack. */
4093 push_obstacks_nochange ();
4094 resume_temporary_allocation ();
4095 cleanup = make_node (POPDCC_EXPR);
4098 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4099 thisblock->data.block.cleanups
4100 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4102 /* If this block has a cleanup, it belongs in stack_block_stack. */
4103 stack_block_stack = thisblock;
4107 /* Arrange for the top element of the dynamic handler chain to be
4108 popped if we exit the current binding contour. DECL is the
4109 associated declaration, if any, otherwise NULL_TREE. If the current
4110 contour is left via an exception, then __sjthrow will pop the top
4111 element off the dynamic handler chain. The code that avoids doing
4112 the action we push into the handler chain in the exceptional case
4113 is contained in expand_cleanups.
4115 This routine is only used by expand_eh_region_start, and that is
4116 the only way in which an exception region should be started. This
4117 routine is only used when using the setjmp/longjmp codegen method
4118 for exception handling. */
4121 expand_dhc_cleanup (decl)
4124 struct nesting *thisblock;
4127 /* Error if we are not in any block. */
4128 if (cfun == 0 || block_stack == 0)
4130 thisblock = block_stack;
4132 /* Record the cleanup for the dynamic handler chain. */
4134 /* All cleanups must be on the function_obstack. */
4135 push_obstacks_nochange ();
4136 resume_temporary_allocation ();
4137 cleanup = make_node (POPDHC_EXPR);
4140 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4141 thisblock->data.block.cleanups
4142 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4144 /* If this block has a cleanup, it belongs in stack_block_stack. */
4145 stack_block_stack = thisblock;
4149 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4150 DECL_ELTS is the list of elements that belong to DECL's type.
4151 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4154 expand_anon_union_decl (decl, cleanup, decl_elts)
4155 tree decl, cleanup, decl_elts;
4157 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4161 /* If any of the elements are addressable, so is the entire union. */
4162 for (t = decl_elts; t; t = TREE_CHAIN (t))
4163 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4165 TREE_ADDRESSABLE (decl) = 1;
4170 expand_decl_cleanup (decl, cleanup);
4171 x = DECL_RTL (decl);
4173 /* Go through the elements, assigning RTL to each. */
4174 for (t = decl_elts; t; t = TREE_CHAIN (t))
4176 tree decl_elt = TREE_VALUE (t);
4177 tree cleanup_elt = TREE_PURPOSE (t);
4178 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4180 /* Propagate the union's alignment to the elements. */
4181 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4182 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4184 /* If the element has BLKmode and the union doesn't, the union is
4185 aligned such that the element doesn't need to have BLKmode, so
4186 change the element's mode to the appropriate one for its size. */
4187 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4188 DECL_MODE (decl_elt) = mode
4189 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4191 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4192 instead create a new MEM rtx with the proper mode. */
4193 if (GET_CODE (x) == MEM)
4195 if (mode == GET_MODE (x))
4196 DECL_RTL (decl_elt) = x;
4199 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4200 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4203 else if (GET_CODE (x) == REG)
4205 if (mode == GET_MODE (x))
4206 DECL_RTL (decl_elt) = x;
4208 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4213 /* Record the cleanup if there is one. */
4216 thisblock->data.block.cleanups
4217 = temp_tree_cons (decl_elt, cleanup_elt,
4218 thisblock->data.block.cleanups);
4222 /* Expand a list of cleanups LIST.
4223 Elements may be expressions or may be nested lists.
4225 If DONT_DO is nonnull, then any list-element
4226 whose TREE_PURPOSE matches DONT_DO is omitted.
4227 This is sometimes used to avoid a cleanup associated with
4228 a value that is being returned out of the scope.
4230 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4231 goto and handle protection regions specially in that case.
4233 If REACHABLE, we emit code, otherwise just inform the exception handling
4234 code about this finalization. */
4237 expand_cleanups (list, dont_do, in_fixup, reachable)
4244 for (tail = list; tail; tail = TREE_CHAIN (tail))
4245 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4247 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4248 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4253 tree cleanup = TREE_VALUE (tail);
4255 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4256 if (TREE_CODE (cleanup) != POPDHC_EXPR
4257 && TREE_CODE (cleanup) != POPDCC_EXPR
4258 /* See expand_eh_region_start_tree for this case. */
4259 && ! TREE_ADDRESSABLE (tail))
4261 cleanup = protect_with_terminate (cleanup);
4262 expand_eh_region_end (cleanup);
4268 /* Cleanups may be run multiple times. For example,
4269 when exiting a binding contour, we expand the
4270 cleanups associated with that contour. When a goto
4271 within that binding contour has a target outside that
4272 contour, it will expand all cleanups from its scope to
4273 the target. Though the cleanups are expanded multiple
4274 times, the control paths are non-overlapping so the
4275 cleanups will not be executed twice. */
4277 /* We may need to protect fixups with rethrow regions. */
4278 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4281 expand_fixup_region_start ();
4283 /* The cleanup might contain try-blocks, so we have to
4284 preserve our current queue. */
4286 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4289 expand_fixup_region_end (TREE_VALUE (tail));
4296 /* Mark when the context we are emitting RTL for as a conditional
4297 context, so that any cleanup actions we register with
4298 expand_decl_init will be properly conditionalized when those
4299 cleanup actions are later performed. Must be called before any
4300 expression (tree) is expanded that is within a conditional context. */
4303 start_cleanup_deferral ()
4305 /* block_stack can be NULL if we are inside the parameter list. It is
4306 OK to do nothing, because cleanups aren't possible here. */
4308 ++block_stack->data.block.conditional_code;
4311 /* Mark the end of a conditional region of code. Because cleanup
4312 deferrals may be nested, we may still be in a conditional region
4313 after we end the currently deferred cleanups, only after we end all
4314 deferred cleanups, are we back in unconditional code. */
4317 end_cleanup_deferral ()
4319 /* block_stack can be NULL if we are inside the parameter list. It is
4320 OK to do nothing, because cleanups aren't possible here. */
4322 --block_stack->data.block.conditional_code;
4325 /* Move all cleanups from the current block_stack
4326 to the containing block_stack, where they are assumed to
4327 have been created. If anything can cause a temporary to
4328 be created, but not expanded for more than one level of
4329 block_stacks, then this code will have to change. */
4334 struct nesting *block = block_stack;
4335 struct nesting *outer = block->next;
4337 outer->data.block.cleanups
4338 = chainon (block->data.block.cleanups,
4339 outer->data.block.cleanups);
4340 block->data.block.cleanups = 0;
4344 last_cleanup_this_contour ()
4346 if (block_stack == 0)
4349 return block_stack->data.block.cleanups;
4352 /* Return 1 if there are any pending cleanups at this point.
4353 If THIS_CONTOUR is nonzero, check the current contour as well.
4354 Otherwise, look only at the contours that enclose this one. */
4357 any_pending_cleanups (this_contour)
4360 struct nesting *block;
4362 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4365 if (this_contour && block_stack->data.block.cleanups != NULL)
4367 if (block_stack->data.block.cleanups == 0
4368 && block_stack->data.block.outer_cleanups == 0)
4371 for (block = block_stack->next; block; block = block->next)
4372 if (block->data.block.cleanups != 0)
4378 /* Enter a case (Pascal) or switch (C) statement.
4379 Push a block onto case_stack and nesting_stack
4380 to accumulate the case-labels that are seen
4381 and to record the labels generated for the statement.
4383 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4384 Otherwise, this construct is transparent for `exit_something'.
4386 EXPR is the index-expression to be dispatched on.
4387 TYPE is its nominal type. We could simply convert EXPR to this type,
4388 but instead we take short cuts. */
4391 expand_start_case (exit_flag, expr, type, printname)
4395 const char *printname;
4397 register struct nesting *thiscase = ALLOC_NESTING ();
4399 /* Make an entry on case_stack for the case we are entering. */
4401 thiscase->next = case_stack;
4402 thiscase->all = nesting_stack;
4403 thiscase->depth = ++nesting_depth;
4404 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4405 thiscase->data.case_stmt.case_list = 0;
4406 thiscase->data.case_stmt.index_expr = expr;
4407 thiscase->data.case_stmt.nominal_type = type;
4408 thiscase->data.case_stmt.default_label = 0;
4409 thiscase->data.case_stmt.num_ranges = 0;
4410 thiscase->data.case_stmt.printname = printname;
4411 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4412 case_stack = thiscase;
4413 nesting_stack = thiscase;
4415 do_pending_stack_adjust ();
4417 /* Make sure case_stmt.start points to something that won't
4418 need any transformation before expand_end_case. */
4419 if (GET_CODE (get_last_insn ()) != NOTE)
4420 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4422 thiscase->data.case_stmt.start = get_last_insn ();
4424 start_cleanup_deferral ();
4427 /* Start a "dummy case statement" within which case labels are invalid
4428 and are not connected to any larger real case statement.
4429 This can be used if you don't want to let a case statement jump
4430 into the middle of certain kinds of constructs. */
4433 expand_start_case_dummy ()
4435 register struct nesting *thiscase = ALLOC_NESTING ();
4437 /* Make an entry on case_stack for the dummy. */
4439 thiscase->next = case_stack;
4440 thiscase->all = nesting_stack;
4441 thiscase->depth = ++nesting_depth;
4442 thiscase->exit_label = 0;
4443 thiscase->data.case_stmt.case_list = 0;
4444 thiscase->data.case_stmt.start = 0;
4445 thiscase->data.case_stmt.nominal_type = 0;
4446 thiscase->data.case_stmt.default_label = 0;
4447 thiscase->data.case_stmt.num_ranges = 0;
4448 case_stack = thiscase;
4449 nesting_stack = thiscase;
4450 start_cleanup_deferral ();
4453 /* End a dummy case statement. */
4456 expand_end_case_dummy ()
4458 end_cleanup_deferral ();
4459 POPSTACK (case_stack);
4462 /* Return the data type of the index-expression
4463 of the innermost case statement, or null if none. */
4466 case_index_expr_type ()
4469 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4476 /* If this is the first label, warn if any insns have been emitted. */
4477 if (case_stack->data.case_stmt.line_number_status >= 0)
4481 restore_line_number_status
4482 (case_stack->data.case_stmt.line_number_status);
4483 case_stack->data.case_stmt.line_number_status = -1;
4485 for (insn = case_stack->data.case_stmt.start;
4487 insn = NEXT_INSN (insn))
4489 if (GET_CODE (insn) == CODE_LABEL)
4491 if (GET_CODE (insn) != NOTE
4492 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4495 insn = PREV_INSN (insn);
4496 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4498 /* If insn is zero, then there must have been a syntax error. */
4500 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4501 NOTE_LINE_NUMBER (insn),
4502 "unreachable code at beginning of %s",
4503 case_stack->data.case_stmt.printname);
4510 /* Accumulate one case or default label inside a case or switch statement.
4511 VALUE is the value of the case (a null pointer, for a default label).
4512 The function CONVERTER, when applied to arguments T and V,
4513 converts the value V to the type T.
4515 If not currently inside a case or switch statement, return 1 and do
4516 nothing. The caller will print a language-specific error message.
4517 If VALUE is a duplicate or overlaps, return 2 and do nothing
4518 except store the (first) duplicate node in *DUPLICATE.
4519 If VALUE is out of range, return 3 and do nothing.
4520 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4521 Return 0 on success.
4523 Extended to handle range statements. */
4526 pushcase (value, converter, label, duplicate)
4527 register tree value;
4528 tree (*converter) PARAMS ((tree, tree));
4529 register tree label;
4535 /* Fail if not inside a real case statement. */
4536 if (! (case_stack && case_stack->data.case_stmt.start))
4539 if (stack_block_stack
4540 && stack_block_stack->depth > case_stack->depth)
4543 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4544 nominal_type = case_stack->data.case_stmt.nominal_type;
4546 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4547 if (index_type == error_mark_node)
4550 /* Convert VALUE to the type in which the comparisons are nominally done. */
4552 value = (*converter) (nominal_type, value);
4556 /* Fail if this value is out of range for the actual type of the index
4557 (which may be narrower than NOMINAL_TYPE). */
4559 && (TREE_CONSTANT_OVERFLOW (value)
4560 || ! int_fits_type_p (value, index_type)))
4563 /* Fail if this is a duplicate or overlaps another entry. */
4566 if (case_stack->data.case_stmt.default_label != 0)
4568 *duplicate = case_stack->data.case_stmt.default_label;
4571 case_stack->data.case_stmt.default_label = label;
4574 return add_case_node (value, value, label, duplicate);
4576 expand_label (label);
4580 /* Like pushcase but this case applies to all values between VALUE1 and
4581 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4582 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4583 starts at VALUE1 and ends at the highest value of the index type.
4584 If both are NULL, this case applies to all values.
4586 The return value is the same as that of pushcase but there is one
4587 additional error code: 4 means the specified range was empty. */
4590 pushcase_range (value1, value2, converter, label, duplicate)
4591 register tree value1, value2;
4592 tree (*converter) PARAMS ((tree, tree));
4593 register tree label;
4599 /* Fail if not inside a real case statement. */
4600 if (! (case_stack && case_stack->data.case_stmt.start))
4603 if (stack_block_stack
4604 && stack_block_stack->depth > case_stack->depth)
4607 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4608 nominal_type = case_stack->data.case_stmt.nominal_type;
4610 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4611 if (index_type == error_mark_node)
4616 /* Convert VALUEs to type in which the comparisons are nominally done
4617 and replace any unspecified value with the corresponding bound. */
4619 value1 = TYPE_MIN_VALUE (index_type);
4621 value2 = TYPE_MAX_VALUE (index_type);
4623 /* Fail if the range is empty. Do this before any conversion since
4624 we want to allow out-of-range empty ranges. */
4625 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4628 /* If the max was unbounded, use the max of the nominal_type we are
4629 converting to. Do this after the < check above to suppress false
4632 value2 = TYPE_MAX_VALUE (nominal_type);
4634 value1 = (*converter) (nominal_type, value1);
4635 value2 = (*converter) (nominal_type, value2);
4637 /* Fail if these values are out of range. */
4638 if (TREE_CONSTANT_OVERFLOW (value1)
4639 || ! int_fits_type_p (value1, index_type))
4642 if (TREE_CONSTANT_OVERFLOW (value2)
4643 || ! int_fits_type_p (value2, index_type))
4646 return add_case_node (value1, value2, label, duplicate);
4649 /* Do the actual insertion of a case label for pushcase and pushcase_range
4650 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4651 slowdown for large switch statements. */
4654 add_case_node (low, high, label, duplicate)
4659 struct case_node *p, **q, *r;
4661 q = &case_stack->data.case_stmt.case_list;
4668 /* Keep going past elements distinctly greater than HIGH. */
4669 if (tree_int_cst_lt (high, p->low))
4672 /* or distinctly less than LOW. */
4673 else if (tree_int_cst_lt (p->high, low))
4678 /* We have an overlap; this is an error. */
4679 *duplicate = p->code_label;
4684 /* Add this label to the chain, and succeed.
4685 Copy LOW, HIGH so they are on temporary rather than momentary
4686 obstack and will thus survive till the end of the case statement. */
4688 r = (struct case_node *) oballoc (sizeof (struct case_node));
4689 r->low = copy_node (low);
4691 /* If the bounds are equal, turn this into the one-value case. */
4693 if (tree_int_cst_equal (low, high))
4697 r->high = copy_node (high);
4698 case_stack->data.case_stmt.num_ranges++;
4701 r->code_label = label;
4702 expand_label (label);
4712 struct case_node *s;
4718 if (! (b = p->balance))
4719 /* Growth propagation from left side. */
4726 if ((p->left = s = r->right))
4735 if ((r->parent = s))
4743 case_stack->data.case_stmt.case_list = r;
4746 /* r->balance == +1 */
4751 struct case_node *t = r->right;
4753 if ((p->left = s = t->right))
4757 if ((r->right = s = t->left))
4771 if ((t->parent = s))
4779 case_stack->data.case_stmt.case_list = t;
4786 /* p->balance == +1; growth of left side balances the node. */
4796 if (! (b = p->balance))
4797 /* Growth propagation from right side. */
4805 if ((p->right = s = r->left))
4813 if ((r->parent = s))
4822 case_stack->data.case_stmt.case_list = r;
4826 /* r->balance == -1 */
4830 struct case_node *t = r->left;
4832 if ((p->right = s = t->left))
4837 if ((r->left = s = t->right))
4851 if ((t->parent = s))
4860 case_stack->data.case_stmt.case_list = t;
4866 /* p->balance == -1; growth of right side balances the node. */
4879 /* Returns the number of possible values of TYPE.
4880 Returns -1 if the number is unknown, variable, or if the number does not
4881 fit in a HOST_WIDE_INT.
4882 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4883 do not increase monotonically (there may be duplicates);
4884 to 1 if the values increase monotonically, but not always by 1;
4885 otherwise sets it to 0. */
4888 all_cases_count (type, spareness)
4893 HOST_WIDE_INT count, minval, lastval;
4897 switch (TREE_CODE (type))
4904 count = 1 << BITS_PER_UNIT;
4909 if (TYPE_MAX_VALUE (type) != 0
4910 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4911 TYPE_MIN_VALUE (type))))
4912 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4913 convert (type, integer_zero_node))))
4914 && host_integerp (t, 1))
4915 count = tree_low_cst (t, 1);
4921 /* Don't waste time with enumeral types with huge values. */
4922 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4923 || TYPE_MAX_VALUE (type) == 0
4924 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4927 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4930 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4932 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4934 if (*spareness == 2 || thisval < lastval)
4936 else if (thisval != minval + count)
4946 #define BITARRAY_TEST(ARRAY, INDEX) \
4947 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4948 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4949 #define BITARRAY_SET(ARRAY, INDEX) \
4950 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4951 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4953 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4954 with the case values we have seen, assuming the case expression
4956 SPARSENESS is as determined by all_cases_count.
4958 The time needed is proportional to COUNT, unless
4959 SPARSENESS is 2, in which case quadratic time is needed. */
4962 mark_seen_cases (type, cases_seen, count, sparseness)
4964 unsigned char *cases_seen;
4965 HOST_WIDE_INT count;
4968 tree next_node_to_try = NULL_TREE;
4969 HOST_WIDE_INT next_node_offset = 0;
4971 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4972 tree val = make_node (INTEGER_CST);
4974 TREE_TYPE (val) = type;
4978 else if (sparseness == 2)
4981 unsigned HOST_WIDE_INT xlo;
4983 /* This less efficient loop is only needed to handle
4984 duplicate case values (multiple enum constants
4985 with the same value). */
4986 TREE_TYPE (val) = TREE_TYPE (root->low);
4987 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4988 t = TREE_CHAIN (t), xlo++)
4990 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4991 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4995 /* Keep going past elements distinctly greater than VAL. */
4996 if (tree_int_cst_lt (val, n->low))
4999 /* or distinctly less than VAL. */
5000 else if (tree_int_cst_lt (n->high, val))
5005 /* We have found a matching range. */
5006 BITARRAY_SET (cases_seen, xlo);
5016 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5018 for (n = root; n; n = n->right)
5020 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5021 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5022 while (! tree_int_cst_lt (n->high, val))
5024 /* Calculate (into xlo) the "offset" of the integer (val).
5025 The element with lowest value has offset 0, the next smallest
5026 element has offset 1, etc. */
5028 unsigned HOST_WIDE_INT xlo;
5032 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5034 /* The TYPE_VALUES will be in increasing order, so
5035 starting searching where we last ended. */
5036 t = next_node_to_try;
5037 xlo = next_node_offset;
5043 t = TYPE_VALUES (type);
5046 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5048 next_node_to_try = TREE_CHAIN (t);
5049 next_node_offset = xlo + 1;
5054 if (t == next_node_to_try)
5063 t = TYPE_MIN_VALUE (type);
5065 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5069 add_double (xlo, xhi,
5070 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5074 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5075 BITARRAY_SET (cases_seen, xlo);
5077 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5079 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5085 /* Called when the index of a switch statement is an enumerated type
5086 and there is no default label.
5088 Checks that all enumeration literals are covered by the case
5089 expressions of a switch. Also, warn if there are any extra
5090 switch cases that are *not* elements of the enumerated type.
5092 If all enumeration literals were covered by the case expressions,
5093 turn one of the expressions into the default expression since it should
5094 not be possible to fall through such a switch. */
5097 check_for_full_enumeration_handling (type)
5100 register struct case_node *n;
5101 register tree chain;
5102 #if 0 /* variable used by 'if 0'ed code below. */
5103 register struct case_node **l;
5107 /* True iff the selector type is a numbered set mode. */
5110 /* The number of possible selector values. */
5113 /* For each possible selector value. a one iff it has been matched
5114 by a case value alternative. */
5115 unsigned char *cases_seen;
5117 /* The allocated size of cases_seen, in chars. */
5118 HOST_WIDE_INT bytes_needed;
5123 size = all_cases_count (type, &sparseness);
5124 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5126 if (size > 0 && size < 600000
5127 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5128 this optimization if we don't have enough memory rather than
5129 aborting, as xmalloc would do. */
5130 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5133 tree v = TYPE_VALUES (type);
5135 /* The time complexity of this code is normally O(N), where
5136 N being the number of members in the enumerated type.
5137 However, if type is a ENUMERAL_TYPE whose values do not
5138 increase monotonically, O(N*log(N)) time may be needed. */
5140 mark_seen_cases (type, cases_seen, size, sparseness);
5142 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5143 if (BITARRAY_TEST (cases_seen, i) == 0)
5144 warning ("enumeration value `%s' not handled in switch",
5145 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5150 /* Now we go the other way around; we warn if there are case
5151 expressions that don't correspond to enumerators. This can
5152 occur since C and C++ don't enforce type-checking of
5153 assignments to enumeration variables. */
5155 if (case_stack->data.case_stmt.case_list
5156 && case_stack->data.case_stmt.case_list->left)
5157 case_stack->data.case_stmt.case_list
5158 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5160 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5162 for (chain = TYPE_VALUES (type);
5163 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5164 chain = TREE_CHAIN (chain))
5169 if (TYPE_NAME (type) == 0)
5170 warning ("case value `%ld' not in enumerated type",
5171 (long) TREE_INT_CST_LOW (n->low));
5173 warning ("case value `%ld' not in enumerated type `%s'",
5174 (long) TREE_INT_CST_LOW (n->low),
5175 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5178 : DECL_NAME (TYPE_NAME (type))));
5180 if (!tree_int_cst_equal (n->low, n->high))
5182 for (chain = TYPE_VALUES (type);
5183 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5184 chain = TREE_CHAIN (chain))
5189 if (TYPE_NAME (type) == 0)
5190 warning ("case value `%ld' not in enumerated type",
5191 (long) TREE_INT_CST_LOW (n->high));
5193 warning ("case value `%ld' not in enumerated type `%s'",
5194 (long) TREE_INT_CST_LOW (n->high),
5195 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5198 : DECL_NAME (TYPE_NAME (type))));
5204 /* ??? This optimization is disabled because it causes valid programs to
5205 fail. ANSI C does not guarantee that an expression with enum type
5206 will have a value that is the same as one of the enumeration literals. */
5208 /* If all values were found as case labels, make one of them the default
5209 label. Thus, this switch will never fall through. We arbitrarily pick
5210 the last one to make the default since this is likely the most
5211 efficient choice. */
5215 for (l = &case_stack->data.case_stmt.case_list;
5220 case_stack->data.case_stmt.default_label = (*l)->code_label;
5227 /* Terminate a case (Pascal) or switch (C) statement
5228 in which ORIG_INDEX is the expression to be tested.
5229 Generate the code to test it and jump to the right place. */
5232 expand_end_case (orig_index)
5235 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5236 rtx default_label = 0;
5237 register struct case_node *n;
5245 register struct nesting *thiscase = case_stack;
5246 tree index_expr, index_type;
5249 /* Don't crash due to previous errors. */
5250 if (thiscase == NULL)
5253 table_label = gen_label_rtx ();
5254 index_expr = thiscase->data.case_stmt.index_expr;
5255 index_type = TREE_TYPE (index_expr);
5256 unsignedp = TREE_UNSIGNED (index_type);
5258 do_pending_stack_adjust ();
5260 /* This might get an spurious warning in the presence of a syntax error;
5261 it could be fixed by moving the call to check_seenlabel after the
5262 check for error_mark_node, and copying the code of check_seenlabel that
5263 deals with case_stack->data.case_stmt.line_number_status /
5264 restore_line_number_status in front of the call to end_cleanup_deferral;
5265 However, this might miss some useful warnings in the presence of
5266 non-syntax errors. */
5269 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5270 if (index_type != error_mark_node)
5272 /* If switch expression was an enumerated type, check that all
5273 enumeration literals are covered by the cases.
5274 No sense trying this if there's a default case, however. */
5276 if (!thiscase->data.case_stmt.default_label
5277 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5278 && TREE_CODE (index_expr) != INTEGER_CST)
5279 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5281 /* If we don't have a default-label, create one here,
5282 after the body of the switch. */
5283 if (thiscase->data.case_stmt.default_label == 0)
5285 thiscase->data.case_stmt.default_label
5286 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5287 expand_label (thiscase->data.case_stmt.default_label);
5289 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5291 before_case = get_last_insn ();
5293 if (thiscase->data.case_stmt.case_list
5294 && thiscase->data.case_stmt.case_list->left)
5295 thiscase->data.case_stmt.case_list
5296 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5298 /* Simplify the case-list before we count it. */
5299 group_case_nodes (thiscase->data.case_stmt.case_list);
5301 /* Get upper and lower bounds of case values.
5302 Also convert all the case values to the index expr's data type. */
5305 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5307 /* Check low and high label values are integers. */
5308 if (TREE_CODE (n->low) != INTEGER_CST)
5310 if (TREE_CODE (n->high) != INTEGER_CST)
5313 n->low = convert (index_type, n->low);
5314 n->high = convert (index_type, n->high);
5316 /* Count the elements and track the largest and smallest
5317 of them (treating them as signed even if they are not). */
5325 if (INT_CST_LT (n->low, minval))
5327 if (INT_CST_LT (maxval, n->high))
5330 /* A range counts double, since it requires two compares. */
5331 if (! tree_int_cst_equal (n->low, n->high))
5335 orig_minval = minval;
5337 /* Compute span of values. */
5339 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5341 end_cleanup_deferral ();
5345 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5347 emit_jump (default_label);
5350 /* If range of values is much bigger than number of values,
5351 make a sequence of conditional branches instead of a dispatch.
5352 If the switch-index is a constant, do it this way
5353 because we can optimize it. */
5355 #ifndef CASE_VALUES_THRESHOLD
5357 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5359 /* If machine does not have a case insn that compares the
5360 bounds, this means extra overhead for dispatch tables
5361 which raises the threshold for using them. */
5362 #define CASE_VALUES_THRESHOLD 5
5363 #endif /* HAVE_casesi */
5364 #endif /* CASE_VALUES_THRESHOLD */
5366 else if (count < CASE_VALUES_THRESHOLD
5367 || compare_tree_int (range, 10 * count) > 0
5368 /* RANGE may be signed, and really large ranges will show up
5369 as negative numbers. */
5370 || compare_tree_int (range, 0) < 0
5371 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5374 || TREE_CODE (index_expr) == INTEGER_CST
5375 /* These will reduce to a constant. */
5376 || (TREE_CODE (index_expr) == CALL_EXPR
5377 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5378 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5379 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5380 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5381 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5382 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5384 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5386 /* If the index is a short or char that we do not have
5387 an insn to handle comparisons directly, convert it to
5388 a full integer now, rather than letting each comparison
5389 generate the conversion. */
5391 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5392 && (cmp_optab->handlers[(int) GET_MODE (index)].insn_code
5393 == CODE_FOR_nothing))
5395 enum machine_mode wider_mode;
5396 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5397 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5398 if (cmp_optab->handlers[(int) wider_mode].insn_code
5399 != CODE_FOR_nothing)
5401 index = convert_to_mode (wider_mode, index, unsignedp);
5407 do_pending_stack_adjust ();
5409 index = protect_from_queue (index, 0);
5410 if (GET_CODE (index) == MEM)
5411 index = copy_to_reg (index);
5412 if (GET_CODE (index) == CONST_INT
5413 || TREE_CODE (index_expr) == INTEGER_CST)
5415 /* Make a tree node with the proper constant value
5416 if we don't already have one. */
5417 if (TREE_CODE (index_expr) != INTEGER_CST)
5420 = build_int_2 (INTVAL (index),
5421 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5422 index_expr = convert (index_type, index_expr);
5425 /* For constant index expressions we need only
5426 issue a unconditional branch to the appropriate
5427 target code. The job of removing any unreachable
5428 code is left to the optimisation phase if the
5429 "-O" option is specified. */
5430 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5431 if (! tree_int_cst_lt (index_expr, n->low)
5432 && ! tree_int_cst_lt (n->high, index_expr))
5436 emit_jump (label_rtx (n->code_label));
5438 emit_jump (default_label);
5442 /* If the index expression is not constant we generate
5443 a binary decision tree to select the appropriate
5444 target code. This is done as follows:
5446 The list of cases is rearranged into a binary tree,
5447 nearly optimal assuming equal probability for each case.
5449 The tree is transformed into RTL, eliminating
5450 redundant test conditions at the same time.
5452 If program flow could reach the end of the
5453 decision tree an unconditional jump to the
5454 default code is emitted. */
5457 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5458 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5459 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5461 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5462 default_label, index_type);
5463 emit_jump_if_reachable (default_label);
5472 enum machine_mode index_mode = SImode;
5473 int index_bits = GET_MODE_BITSIZE (index_mode);
5475 enum machine_mode op_mode;
5477 /* Convert the index to SImode. */
5478 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5479 > GET_MODE_BITSIZE (index_mode))
5481 enum machine_mode omode = TYPE_MODE (index_type);
5482 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5484 /* We must handle the endpoints in the original mode. */
5485 index_expr = build (MINUS_EXPR, index_type,
5486 index_expr, minval);
5487 minval = integer_zero_node;
5488 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5489 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5490 omode, 1, 0, default_label);
5491 /* Now we can safely truncate. */
5492 index = convert_to_mode (index_mode, index, 0);
5496 if (TYPE_MODE (index_type) != index_mode)
5498 index_expr = convert (type_for_size (index_bits, 0),
5500 index_type = TREE_TYPE (index_expr);
5503 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5506 index = protect_from_queue (index, 0);
5507 do_pending_stack_adjust ();
5509 op_mode = insn_data[(int) CODE_FOR_casesi].operand[0].mode;
5510 if (! (*insn_data[(int) CODE_FOR_casesi].operand[0].predicate)
5512 index = copy_to_mode_reg (op_mode, index);
5514 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5516 op_mode = insn_data[(int) CODE_FOR_casesi].operand[1].mode;
5517 if (! (*insn_data[(int) CODE_FOR_casesi].operand[1].predicate)
5519 op1 = copy_to_mode_reg (op_mode, op1);
5521 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5523 op_mode = insn_data[(int) CODE_FOR_casesi].operand[2].mode;
5524 if (! (*insn_data[(int) CODE_FOR_casesi].operand[2].predicate)
5526 op2 = copy_to_mode_reg (op_mode, op2);
5528 emit_jump_insn (gen_casesi (index, op1, op2,
5529 table_label, default_label));
5533 #ifdef HAVE_tablejump
5534 if (! win && HAVE_tablejump)
5536 index_type = thiscase->data.case_stmt.nominal_type;
5537 index_expr = fold (build (MINUS_EXPR, index_type,
5538 convert (index_type, index_expr),
5539 convert (index_type, minval)));
5540 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5542 index = protect_from_queue (index, 0);
5543 do_pending_stack_adjust ();
5545 do_tablejump (index, TYPE_MODE (index_type),
5546 expand_expr (range, NULL_RTX, VOIDmode, 0),
5547 table_label, default_label);
5554 /* Get table of labels to jump to, in order of case index. */
5556 ncases = TREE_INT_CST_LOW (range) + 1;
5557 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5558 bzero ((char *) labelvec, ncases * sizeof (rtx));
5560 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5562 register HOST_WIDE_INT i
5563 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5568 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5569 if (i + TREE_INT_CST_LOW (orig_minval)
5570 == TREE_INT_CST_LOW (n->high))
5576 /* Fill in the gaps with the default. */
5577 for (i = 0; i < ncases; i++)
5578 if (labelvec[i] == 0)
5579 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5581 /* Output the table */
5582 emit_label (table_label);
5584 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5585 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5586 gen_rtx_LABEL_REF (Pmode, table_label),
5587 gen_rtvec_v (ncases, labelvec),
5588 const0_rtx, const0_rtx));
5590 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5591 gen_rtvec_v (ncases, labelvec)));
5593 /* If the case insn drops through the table,
5594 after the table we must jump to the default-label.
5595 Otherwise record no drop-through after the table. */
5596 #ifdef CASE_DROPS_THROUGH
5597 emit_jump (default_label);
5603 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5604 reorder_insns (before_case, get_last_insn (),
5605 thiscase->data.case_stmt.start);
5608 end_cleanup_deferral ();
5610 if (thiscase->exit_label)
5611 emit_label (thiscase->exit_label);
5613 POPSTACK (case_stack);
5618 /* Convert the tree NODE into a list linked by the right field, with the left
5619 field zeroed. RIGHT is used for recursion; it is a list to be placed
5620 rightmost in the resulting list. */
5622 static struct case_node *
5623 case_tree2list (node, right)
5624 struct case_node *node, *right;
5626 struct case_node *left;
5629 right = case_tree2list (node->right, right);
5631 node->right = right;
5632 if ((left = node->left))
5635 return case_tree2list (left, node);
5641 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5644 do_jump_if_equal (op1, op2, label, unsignedp)
5645 rtx op1, op2, label;
5648 if (GET_CODE (op1) == CONST_INT
5649 && GET_CODE (op2) == CONST_INT)
5651 if (INTVAL (op1) == INTVAL (op2))
5656 enum machine_mode mode = GET_MODE (op1);
5657 if (mode == VOIDmode)
5658 mode = GET_MODE (op2);
5659 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5664 /* Not all case values are encountered equally. This function
5665 uses a heuristic to weight case labels, in cases where that
5666 looks like a reasonable thing to do.
5668 Right now, all we try to guess is text, and we establish the
5671 chars above space: 16
5680 If we find any cases in the switch that are not either -1 or in the range
5681 of valid ASCII characters, or are control characters other than those
5682 commonly used with "\", don't treat this switch scanning text.
5684 Return 1 if these nodes are suitable for cost estimation, otherwise
5688 estimate_case_costs (node)
5691 tree min_ascii = build_int_2 (-1, -1);
5692 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5696 /* If we haven't already made the cost table, make it now. Note that the
5697 lower bound of the table is -1, not zero. */
5699 if (cost_table == NULL)
5701 cost_table = cost_table_ + 1;
5703 for (i = 0; i < 128; i++)
5707 else if (ISPUNCT (i))
5709 else if (ISCNTRL (i))
5713 cost_table[' '] = 8;
5714 cost_table['\t'] = 4;
5715 cost_table['\0'] = 4;
5716 cost_table['\n'] = 2;
5717 cost_table['\f'] = 1;
5718 cost_table['\v'] = 1;
5719 cost_table['\b'] = 1;
5722 /* See if all the case expressions look like text. It is text if the
5723 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5724 as signed arithmetic since we don't want to ever access cost_table with a
5725 value less than -1. Also check that none of the constants in a range
5726 are strange control characters. */
5728 for (n = node; n; n = n->right)
5730 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5733 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5734 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5735 if (cost_table[i] < 0)
5739 /* All interesting values are within the range of interesting
5740 ASCII characters. */
5744 /* Scan an ordered list of case nodes
5745 combining those with consecutive values or ranges.
5747 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5750 group_case_nodes (head)
5753 case_node_ptr node = head;
5757 rtx lb = next_real_insn (label_rtx (node->code_label));
5759 case_node_ptr np = node;
5761 /* Try to group the successors of NODE with NODE. */
5762 while (((np = np->right) != 0)
5763 /* Do they jump to the same place? */
5764 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5765 || (lb != 0 && lb2 != 0
5766 && simplejump_p (lb)
5767 && simplejump_p (lb2)
5768 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5769 SET_SRC (PATTERN (lb2)))))
5770 /* Are their ranges consecutive? */
5771 && tree_int_cst_equal (np->low,
5772 fold (build (PLUS_EXPR,
5773 TREE_TYPE (node->high),
5776 /* An overflow is not consecutive. */
5777 && tree_int_cst_lt (node->high,
5778 fold (build (PLUS_EXPR,
5779 TREE_TYPE (node->high),
5781 integer_one_node))))
5783 node->high = np->high;
5785 /* NP is the first node after NODE which can't be grouped with it.
5786 Delete the nodes in between, and move on to that node. */
5792 /* Take an ordered list of case nodes
5793 and transform them into a near optimal binary tree,
5794 on the assumption that any target code selection value is as
5795 likely as any other.
5797 The transformation is performed by splitting the ordered
5798 list into two equal sections plus a pivot. The parts are
5799 then attached to the pivot as left and right branches. Each
5800 branch is then transformed recursively. */
5803 balance_case_nodes (head, parent)
5804 case_node_ptr *head;
5805 case_node_ptr parent;
5807 register case_node_ptr np;
5815 register case_node_ptr *npp;
5818 /* Count the number of entries on branch. Also count the ranges. */
5822 if (!tree_int_cst_equal (np->low, np->high))
5826 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5830 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5838 /* Split this list if it is long enough for that to help. */
5843 /* Find the place in the list that bisects the list's total cost,
5844 Here I gets half the total cost. */
5849 /* Skip nodes while their cost does not reach that amount. */
5850 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5851 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5852 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5855 npp = &(*npp)->right;
5860 /* Leave this branch lopsided, but optimize left-hand
5861 side and fill in `parent' fields for right-hand side. */
5863 np->parent = parent;
5864 balance_case_nodes (&np->left, np);
5865 for (; np->right; np = np->right)
5866 np->right->parent = np;
5870 /* If there are just three nodes, split at the middle one. */
5872 npp = &(*npp)->right;
5875 /* Find the place in the list that bisects the list's total cost,
5876 where ranges count as 2.
5877 Here I gets half the total cost. */
5878 i = (i + ranges + 1) / 2;
5881 /* Skip nodes while their cost does not reach that amount. */
5882 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5887 npp = &(*npp)->right;
5892 np->parent = parent;
5895 /* Optimize each of the two split parts. */
5896 balance_case_nodes (&np->left, np);
5897 balance_case_nodes (&np->right, np);
5901 /* Else leave this branch as one level,
5902 but fill in `parent' fields. */
5904 np->parent = parent;
5905 for (; np->right; np = np->right)
5906 np->right->parent = np;
5911 /* Search the parent sections of the case node tree
5912 to see if a test for the lower bound of NODE would be redundant.
5913 INDEX_TYPE is the type of the index expression.
5915 The instructions to generate the case decision tree are
5916 output in the same order as nodes are processed so it is
5917 known that if a parent node checks the range of the current
5918 node minus one that the current node is bounded at its lower
5919 span. Thus the test would be redundant. */
5922 node_has_low_bound (node, index_type)
5927 case_node_ptr pnode;
5929 /* If the lower bound of this node is the lowest value in the index type,
5930 we need not test it. */
5932 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5935 /* If this node has a left branch, the value at the left must be less
5936 than that at this node, so it cannot be bounded at the bottom and
5937 we need not bother testing any further. */
5942 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5943 node->low, integer_one_node));
5945 /* If the subtraction above overflowed, we can't verify anything.
5946 Otherwise, look for a parent that tests our value - 1. */
5948 if (! tree_int_cst_lt (low_minus_one, node->low))
5951 for (pnode = node->parent; pnode; pnode = pnode->parent)
5952 if (tree_int_cst_equal (low_minus_one, pnode->high))
5958 /* Search the parent sections of the case node tree
5959 to see if a test for the upper bound of NODE would be redundant.
5960 INDEX_TYPE is the type of the index expression.
5962 The instructions to generate the case decision tree are
5963 output in the same order as nodes are processed so it is
5964 known that if a parent node checks the range of the current
5965 node plus one that the current node is bounded at its upper
5966 span. Thus the test would be redundant. */
5969 node_has_high_bound (node, index_type)
5974 case_node_ptr pnode;
5976 /* If there is no upper bound, obviously no test is needed. */
5978 if (TYPE_MAX_VALUE (index_type) == NULL)
5981 /* If the upper bound of this node is the highest value in the type
5982 of the index expression, we need not test against it. */
5984 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5987 /* If this node has a right branch, the value at the right must be greater
5988 than that at this node, so it cannot be bounded at the top and
5989 we need not bother testing any further. */
5994 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5995 node->high, integer_one_node));
5997 /* If the addition above overflowed, we can't verify anything.
5998 Otherwise, look for a parent that tests our value + 1. */
6000 if (! tree_int_cst_lt (node->high, high_plus_one))
6003 for (pnode = node->parent; pnode; pnode = pnode->parent)
6004 if (tree_int_cst_equal (high_plus_one, pnode->low))
6010 /* Search the parent sections of the
6011 case node tree to see if both tests for the upper and lower
6012 bounds of NODE would be redundant. */
6015 node_is_bounded (node, index_type)
6019 return (node_has_low_bound (node, index_type)
6020 && node_has_high_bound (node, index_type));
6023 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6026 emit_jump_if_reachable (label)
6029 if (GET_CODE (get_last_insn ()) != BARRIER)
6033 /* Emit step-by-step code to select a case for the value of INDEX.
6034 The thus generated decision tree follows the form of the
6035 case-node binary tree NODE, whose nodes represent test conditions.
6036 INDEX_TYPE is the type of the index of the switch.
6038 Care is taken to prune redundant tests from the decision tree
6039 by detecting any boundary conditions already checked by
6040 emitted rtx. (See node_has_high_bound, node_has_low_bound
6041 and node_is_bounded, above.)
6043 Where the test conditions can be shown to be redundant we emit
6044 an unconditional jump to the target code. As a further
6045 optimization, the subordinates of a tree node are examined to
6046 check for bounded nodes. In this case conditional and/or
6047 unconditional jumps as a result of the boundary check for the
6048 current node are arranged to target the subordinates associated
6049 code for out of bound conditions on the current node.
6051 We can assume that when control reaches the code generated here,
6052 the index value has already been compared with the parents
6053 of this node, and determined to be on the same side of each parent
6054 as this node is. Thus, if this node tests for the value 51,
6055 and a parent tested for 52, we don't need to consider
6056 the possibility of a value greater than 51. If another parent
6057 tests for the value 50, then this node need not test anything. */
6060 emit_case_nodes (index, node, default_label, index_type)
6066 /* If INDEX has an unsigned type, we must make unsigned branches. */
6067 int unsignedp = TREE_UNSIGNED (index_type);
6068 enum machine_mode mode = GET_MODE (index);
6070 /* See if our parents have already tested everything for us.
6071 If they have, emit an unconditional jump for this node. */
6072 if (node_is_bounded (node, index_type))
6073 emit_jump (label_rtx (node->code_label));
6075 else if (tree_int_cst_equal (node->low, node->high))
6077 /* Node is single valued. First see if the index expression matches
6078 this node and then check our children, if any. */
6080 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6081 label_rtx (node->code_label), unsignedp);
6083 if (node->right != 0 && node->left != 0)
6085 /* This node has children on both sides.
6086 Dispatch to one side or the other
6087 by comparing the index value with this node's value.
6088 If one subtree is bounded, check that one first,
6089 so we can avoid real branches in the tree. */
6091 if (node_is_bounded (node->right, index_type))
6093 emit_cmp_and_jump_insns (index,
6094 expand_expr (node->high, NULL_RTX,
6096 GT, NULL_RTX, mode, unsignedp, 0,
6097 label_rtx (node->right->code_label));
6098 emit_case_nodes (index, node->left, default_label, index_type);
6101 else if (node_is_bounded (node->left, index_type))
6103 emit_cmp_and_jump_insns (index,
6104 expand_expr (node->high, NULL_RTX,
6106 LT, NULL_RTX, mode, unsignedp, 0,
6107 label_rtx (node->left->code_label));
6108 emit_case_nodes (index, node->right, default_label, index_type);
6113 /* Neither node is bounded. First distinguish the two sides;
6114 then emit the code for one side at a time. */
6116 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6118 /* See if the value is on the right. */
6119 emit_cmp_and_jump_insns (index,
6120 expand_expr (node->high, NULL_RTX,
6122 GT, NULL_RTX, mode, unsignedp, 0,
6123 label_rtx (test_label));
6125 /* Value must be on the left.
6126 Handle the left-hand subtree. */
6127 emit_case_nodes (index, node->left, default_label, index_type);
6128 /* If left-hand subtree does nothing,
6130 emit_jump_if_reachable (default_label);
6132 /* Code branches here for the right-hand subtree. */
6133 expand_label (test_label);
6134 emit_case_nodes (index, node->right, default_label, index_type);
6138 else if (node->right != 0 && node->left == 0)
6140 /* Here we have a right child but no left so we issue conditional
6141 branch to default and process the right child.
6143 Omit the conditional branch to default if we it avoid only one
6144 right child; it costs too much space to save so little time. */
6146 if (node->right->right || node->right->left
6147 || !tree_int_cst_equal (node->right->low, node->right->high))
6149 if (!node_has_low_bound (node, index_type))
6151 emit_cmp_and_jump_insns (index,
6152 expand_expr (node->high, NULL_RTX,
6154 LT, NULL_RTX, mode, unsignedp, 0,
6158 emit_case_nodes (index, node->right, default_label, index_type);
6161 /* We cannot process node->right normally
6162 since we haven't ruled out the numbers less than
6163 this node's value. So handle node->right explicitly. */
6164 do_jump_if_equal (index,
6165 expand_expr (node->right->low, NULL_RTX,
6167 label_rtx (node->right->code_label), unsignedp);
6170 else if (node->right == 0 && node->left != 0)
6172 /* Just one subtree, on the left. */
6174 #if 0 /* The following code and comment were formerly part
6175 of the condition here, but they didn't work
6176 and I don't understand what the idea was. -- rms. */
6177 /* If our "most probable entry" is less probable
6178 than the default label, emit a jump to
6179 the default label using condition codes
6180 already lying around. With no right branch,
6181 a branch-greater-than will get us to the default
6184 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6187 if (node->left->left || node->left->right
6188 || !tree_int_cst_equal (node->left->low, node->left->high))
6190 if (!node_has_high_bound (node, index_type))
6192 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6195 GT, NULL_RTX, mode, unsignedp, 0,
6199 emit_case_nodes (index, node->left, default_label, index_type);
6202 /* We cannot process node->left normally
6203 since we haven't ruled out the numbers less than
6204 this node's value. So handle node->left explicitly. */
6205 do_jump_if_equal (index,
6206 expand_expr (node->left->low, NULL_RTX,
6208 label_rtx (node->left->code_label), unsignedp);
6213 /* Node is a range. These cases are very similar to those for a single
6214 value, except that we do not start by testing whether this node
6215 is the one to branch to. */
6217 if (node->right != 0 && node->left != 0)
6219 /* Node has subtrees on both sides.
6220 If the right-hand subtree is bounded,
6221 test for it first, since we can go straight there.
6222 Otherwise, we need to make a branch in the control structure,
6223 then handle the two subtrees. */
6224 tree test_label = 0;
6226 if (node_is_bounded (node->right, index_type))
6227 /* Right hand node is fully bounded so we can eliminate any
6228 testing and branch directly to the target code. */
6229 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6231 GT, NULL_RTX, mode, unsignedp, 0,
6232 label_rtx (node->right->code_label));
6235 /* Right hand node requires testing.
6236 Branch to a label where we will handle it later. */
6238 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6239 emit_cmp_and_jump_insns (index,
6240 expand_expr (node->high, NULL_RTX,
6242 GT, NULL_RTX, mode, unsignedp, 0,
6243 label_rtx (test_label));
6246 /* Value belongs to this node or to the left-hand subtree. */
6248 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6250 GE, NULL_RTX, mode, unsignedp, 0,
6251 label_rtx (node->code_label));
6253 /* Handle the left-hand subtree. */
6254 emit_case_nodes (index, node->left, default_label, index_type);
6256 /* If right node had to be handled later, do that now. */
6260 /* If the left-hand subtree fell through,
6261 don't let it fall into the right-hand subtree. */
6262 emit_jump_if_reachable (default_label);
6264 expand_label (test_label);
6265 emit_case_nodes (index, node->right, default_label, index_type);
6269 else if (node->right != 0 && node->left == 0)
6271 /* Deal with values to the left of this node,
6272 if they are possible. */
6273 if (!node_has_low_bound (node, index_type))
6275 emit_cmp_and_jump_insns (index,
6276 expand_expr (node->low, NULL_RTX,
6278 LT, NULL_RTX, mode, unsignedp, 0,
6282 /* Value belongs to this node or to the right-hand subtree. */
6284 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6286 LE, NULL_RTX, mode, unsignedp, 0,
6287 label_rtx (node->code_label));
6289 emit_case_nodes (index, node->right, default_label, index_type);
6292 else if (node->right == 0 && node->left != 0)
6294 /* Deal with values to the right of this node,
6295 if they are possible. */
6296 if (!node_has_high_bound (node, index_type))
6298 emit_cmp_and_jump_insns (index,
6299 expand_expr (node->high, NULL_RTX,
6301 GT, NULL_RTX, mode, unsignedp, 0,
6305 /* Value belongs to this node or to the left-hand subtree. */
6307 emit_cmp_and_jump_insns (index,
6308 expand_expr (node->low, NULL_RTX,
6310 GE, NULL_RTX, mode, unsignedp, 0,
6311 label_rtx (node->code_label));
6313 emit_case_nodes (index, node->left, default_label, index_type);
6318 /* Node has no children so we check low and high bounds to remove
6319 redundant tests. Only one of the bounds can exist,
6320 since otherwise this node is bounded--a case tested already. */
6322 if (!node_has_high_bound (node, index_type))
6324 emit_cmp_and_jump_insns (index,
6325 expand_expr (node->high, NULL_RTX,
6327 GT, NULL_RTX, mode, unsignedp, 0,
6331 if (!node_has_low_bound (node, index_type))
6333 emit_cmp_and_jump_insns (index,
6334 expand_expr (node->low, NULL_RTX,
6336 LT, NULL_RTX, mode, unsignedp, 0,
6340 emit_jump (label_rtx (node->code_label));