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 /* Name of this kind of statement, for warnings. */
244 const char *printname;
245 /* Used to save no_line_numbers till we see the first case label.
246 We set this to -1 when we see the first case label in this
248 int line_number_status;
253 /* Allocate and return a new `struct nesting'. */
255 #define ALLOC_NESTING() \
256 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
258 /* Pop the nesting stack element by element until we pop off
259 the element which is at the top of STACK.
260 Update all the other stacks, popping off elements from them
261 as we pop them from nesting_stack. */
263 #define POPSTACK(STACK) \
264 do { struct nesting *target = STACK; \
265 struct nesting *this; \
266 do { this = nesting_stack; \
267 if (loop_stack == this) \
268 loop_stack = loop_stack->next; \
269 if (cond_stack == this) \
270 cond_stack = cond_stack->next; \
271 if (block_stack == this) \
272 block_stack = block_stack->next; \
273 if (stack_block_stack == this) \
274 stack_block_stack = stack_block_stack->next; \
275 if (case_stack == this) \
276 case_stack = case_stack->next; \
277 nesting_depth = nesting_stack->depth - 1; \
278 nesting_stack = this->all; \
279 obstack_free (&stmt_obstack, this); } \
280 while (this != target); } while (0)
282 /* In some cases it is impossible to generate code for a forward goto
283 until the label definition is seen. This happens when it may be necessary
284 for the goto to reset the stack pointer: we don't yet know how to do that.
285 So expand_goto puts an entry on this fixup list.
286 Each time a binding contour that resets the stack is exited,
288 If the target label has now been defined, we can insert the proper code. */
292 /* Points to following fixup. */
293 struct goto_fixup *next;
294 /* Points to the insn before the jump insn.
295 If more code must be inserted, it goes after this insn. */
297 /* The LABEL_DECL that this jump is jumping to, or 0
298 for break, continue or return. */
300 /* The BLOCK for the place where this goto was found. */
302 /* The CODE_LABEL rtx that this is jumping to. */
304 /* Number of binding contours started in current function
305 before the label reference. */
306 int block_start_count;
307 /* The outermost stack level that should be restored for this jump.
308 Each time a binding contour that resets the stack is exited,
309 if the target label is *not* yet defined, this slot is updated. */
311 /* List of lists of cleanup expressions to be run by this goto.
312 There is one element for each block that this goto is within.
313 The tail of this list can be 0,
314 if all remaining elements would be empty.
315 The TREE_VALUE contains the cleanup list of that block as of the
316 time this goto was seen.
317 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
318 tree cleanup_list_list;
321 /* Within any binding contour that must restore a stack level,
322 all labels are recorded with a chain of these structures. */
326 /* Points to following fixup. */
327 struct label_chain *next;
333 /* Chain of all pending binding contours. */
334 struct nesting *x_block_stack;
336 /* If any new stacks are added here, add them to POPSTACKS too. */
338 /* Chain of all pending binding contours that restore stack levels
340 struct nesting *x_stack_block_stack;
342 /* Chain of all pending conditional statements. */
343 struct nesting *x_cond_stack;
345 /* Chain of all pending loops. */
346 struct nesting *x_loop_stack;
348 /* Chain of all pending case or switch statements. */
349 struct nesting *x_case_stack;
351 /* Separate chain including all of the above,
352 chained through the `all' field. */
353 struct nesting *x_nesting_stack;
355 /* Number of entries on nesting_stack now. */
358 /* Number of binding contours started so far in this function. */
359 int x_block_start_count;
361 /* Each time we expand an expression-statement,
362 record the expr's type and its RTL value here. */
363 tree x_last_expr_type;
364 rtx x_last_expr_value;
366 /* Nonzero if within a ({...}) grouping, in which case we must
367 always compute a value for each expr-stmt in case it is the last one. */
368 int x_expr_stmts_for_value;
370 /* Filename and line number of last line-number note,
371 whether we actually emitted it or not. */
372 const char *x_emit_filename;
375 struct goto_fixup *x_goto_fixup_chain;
378 #define block_stack (cfun->stmt->x_block_stack)
379 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
380 #define cond_stack (cfun->stmt->x_cond_stack)
381 #define loop_stack (cfun->stmt->x_loop_stack)
382 #define case_stack (cfun->stmt->x_case_stack)
383 #define nesting_stack (cfun->stmt->x_nesting_stack)
384 #define nesting_depth (cfun->stmt->x_nesting_depth)
385 #define current_block_start_count (cfun->stmt->x_block_start_count)
386 #define last_expr_type (cfun->stmt->x_last_expr_type)
387 #define last_expr_value (cfun->stmt->x_last_expr_value)
388 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
389 #define emit_filename (cfun->stmt->x_emit_filename)
390 #define emit_lineno (cfun->stmt->x_emit_lineno)
391 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
393 /* Non-zero if we are using EH to handle cleanus. */
394 static int using_eh_for_cleanups_p = 0;
396 /* Character strings, each containing a single decimal digit. */
397 static const char *digit_strings[10];
399 static int n_occurrences PARAMS ((int, const char *));
400 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
401 static int expand_fixup PARAMS ((tree, rtx, rtx));
402 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
403 static void expand_nl_goto_receiver PARAMS ((void));
404 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
405 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
407 static void expand_null_return_1 PARAMS ((rtx, int));
408 static void expand_value_return PARAMS ((rtx));
409 static int tail_recursion_args PARAMS ((tree, tree));
410 static void expand_cleanups PARAMS ((tree, tree, int, int));
411 static void check_seenlabel PARAMS ((void));
412 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
413 static int estimate_case_costs PARAMS ((case_node_ptr));
414 static void group_case_nodes PARAMS ((case_node_ptr));
415 static void balance_case_nodes PARAMS ((case_node_ptr *,
417 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
418 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
419 static int node_is_bounded PARAMS ((case_node_ptr, tree));
420 static void emit_jump_if_reachable PARAMS ((rtx));
421 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
422 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
423 static void mark_cond_nesting PARAMS ((struct nesting *));
424 static void mark_loop_nesting PARAMS ((struct nesting *));
425 static void mark_block_nesting PARAMS ((struct nesting *));
426 static void mark_case_nesting PARAMS ((struct nesting *));
427 static void mark_case_node PARAMS ((struct case_node *));
428 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
429 static void free_case_nodes PARAMS ((case_node_ptr));
432 using_eh_for_cleanups ()
434 using_eh_for_cleanups_p = 1;
437 /* Mark N (known to be a cond-nesting) for GC. */
440 mark_cond_nesting (n)
445 ggc_mark_rtx (n->exit_label);
446 ggc_mark_rtx (n->data.cond.endif_label);
447 ggc_mark_rtx (n->data.cond.next_label);
453 /* Mark N (known to be a loop-nesting) for GC. */
456 mark_loop_nesting (n)
462 ggc_mark_rtx (n->exit_label);
463 ggc_mark_rtx (n->data.loop.start_label);
464 ggc_mark_rtx (n->data.loop.end_label);
465 ggc_mark_rtx (n->data.loop.alt_end_label);
466 ggc_mark_rtx (n->data.loop.continue_label);
472 /* Mark N (known to be a block-nesting) for GC. */
475 mark_block_nesting (n)
480 struct label_chain *l;
482 ggc_mark_rtx (n->exit_label);
483 ggc_mark_rtx (n->data.block.stack_level);
484 ggc_mark_rtx (n->data.block.first_insn);
485 ggc_mark_tree (n->data.block.cleanups);
486 ggc_mark_tree (n->data.block.outer_cleanups);
488 for (l = n->data.block.label_chain; l != NULL; l = l->next)
491 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);
603 gcc_obstack_init (&stmt_obstack);
606 for (i = 0; i < 10; i++)
609 digit_strings[i] = ggc_alloc_string (buf, 1);
611 ggc_add_string_root (digit_strings, 10);
615 init_stmt_for_function ()
617 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
619 /* We are not currently within any block, conditional, loop or case. */
621 stack_block_stack = 0;
628 current_block_start_count = 0;
630 /* No gotos have been expanded yet. */
631 goto_fixup_chain = 0;
633 /* We are not processing a ({...}) grouping. */
634 expr_stmts_for_value = 0;
636 last_expr_value = NULL_RTX;
639 /* Return nonzero if anything is pushed on the loop, condition, or case
644 return cond_stack || loop_stack || case_stack;
647 /* Record the current file and line. Called from emit_line_note. */
649 set_file_and_line_for_stmt (file, line)
653 /* If we're outputting an inline function, and we add a line note,
654 there may be no CFUN->STMT information. So, there's no need to
658 emit_filename = file;
663 /* Emit a no-op instruction. */
670 last_insn = get_last_insn ();
672 && (GET_CODE (last_insn) == CODE_LABEL
673 || (GET_CODE (last_insn) == NOTE
674 && prev_real_insn (last_insn) == 0)))
675 emit_insn (gen_nop ());
678 /* Return the rtx-label that corresponds to a LABEL_DECL,
679 creating it if necessary. */
685 if (TREE_CODE (label) != LABEL_DECL)
688 if (DECL_RTL (label))
689 return DECL_RTL (label);
691 return DECL_RTL (label) = gen_label_rtx ();
694 /* Add an unconditional jump to LABEL as the next sequential instruction. */
700 do_pending_stack_adjust ();
701 emit_jump_insn (gen_jump (label));
705 /* Emit code to jump to the address
706 specified by the pointer expression EXP. */
709 expand_computed_goto (exp)
712 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
714 #ifdef POINTERS_EXTEND_UNSIGNED
715 x = convert_memory_address (Pmode, x);
719 /* Be sure the function is executable. */
720 if (current_function_check_memory_usage)
721 emit_library_call (chkr_check_exec_libfunc, LCT_CONST_MAKE_BLOCK,
722 VOIDmode, 1, x, ptr_mode);
724 do_pending_stack_adjust ();
725 emit_indirect_jump (x);
727 current_function_has_computed_jump = 1;
730 /* Handle goto statements and the labels that they can go to. */
732 /* Specify the location in the RTL code of a label LABEL,
733 which is a LABEL_DECL tree node.
735 This is used for the kind of label that the user can jump to with a
736 goto statement, and for alternatives of a switch or case statement.
737 RTL labels generated for loops and conditionals don't go through here;
738 they are generated directly at the RTL level, by other functions below.
740 Note that this has nothing to do with defining label *names*.
741 Languages vary in how they do that and what that even means. */
747 struct label_chain *p;
749 do_pending_stack_adjust ();
750 emit_label (label_rtx (label));
751 if (DECL_NAME (label))
752 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
754 if (stack_block_stack != 0)
756 p = (struct label_chain *) ggc_alloc (sizeof (struct label_chain));
757 p->next = stack_block_stack->data.block.label_chain;
758 stack_block_stack->data.block.label_chain = p;
763 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
764 from nested functions. */
767 declare_nonlocal_label (label)
770 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
772 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
773 LABEL_PRESERVE_P (label_rtx (label)) = 1;
774 if (nonlocal_goto_handler_slots == 0)
776 emit_stack_save (SAVE_NONLOCAL,
777 &nonlocal_goto_stack_level,
778 PREV_INSN (tail_recursion_reentry));
780 nonlocal_goto_handler_slots
781 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
784 /* Generate RTL code for a `goto' statement with target label LABEL.
785 LABEL should be a LABEL_DECL tree node that was or will later be
786 defined with `expand_label'. */
794 /* Check for a nonlocal goto to a containing function. */
795 context = decl_function_context (label);
796 if (context != 0 && context != current_function_decl)
798 struct function *p = find_function_data (context);
799 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
800 rtx handler_slot, static_chain, save_area;
803 /* Find the corresponding handler slot for this label. */
804 handler_slot = p->x_nonlocal_goto_handler_slots;
805 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
806 link = TREE_CHAIN (link))
807 handler_slot = XEXP (handler_slot, 1);
808 handler_slot = XEXP (handler_slot, 0);
810 p->has_nonlocal_label = 1;
811 current_function_has_nonlocal_goto = 1;
812 LABEL_REF_NONLOCAL_P (label_ref) = 1;
814 /* Copy the rtl for the slots so that they won't be shared in
815 case the virtual stack vars register gets instantiated differently
816 in the parent than in the child. */
818 static_chain = copy_to_reg (lookup_static_chain (label));
820 /* Get addr of containing function's current nonlocal goto handler,
821 which will do any cleanups and then jump to the label. */
822 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
823 virtual_stack_vars_rtx,
826 /* Get addr of containing function's nonlocal save area. */
827 save_area = p->x_nonlocal_goto_stack_level;
829 save_area = replace_rtx (copy_rtx (save_area),
830 virtual_stack_vars_rtx, static_chain);
832 #if HAVE_nonlocal_goto
833 if (HAVE_nonlocal_goto)
834 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
835 save_area, label_ref));
839 /* Restore frame pointer for containing function.
840 This sets the actual hard register used for the frame pointer
841 to the location of the function's incoming static chain info.
842 The non-local goto handler will then adjust it to contain the
843 proper value and reload the argument pointer, if needed. */
844 emit_move_insn (hard_frame_pointer_rtx, static_chain);
845 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
847 /* USE of hard_frame_pointer_rtx added for consistency;
848 not clear if really needed. */
849 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
850 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
851 emit_indirect_jump (handler_slot);
855 expand_goto_internal (label, label_rtx (label), NULL_RTX);
858 /* Generate RTL code for a `goto' statement with target label BODY.
859 LABEL should be a LABEL_REF.
860 LAST_INSN, if non-0, is the rtx we should consider as the last
861 insn emitted (for the purposes of cleaning up a return). */
864 expand_goto_internal (body, label, last_insn)
869 struct nesting *block;
872 if (GET_CODE (label) != CODE_LABEL)
875 /* If label has already been defined, we can tell now
876 whether and how we must alter the stack level. */
878 if (PREV_INSN (label) != 0)
880 /* Find the innermost pending block that contains the label.
881 (Check containment by comparing insn-uids.)
882 Then restore the outermost stack level within that block,
883 and do cleanups of all blocks contained in it. */
884 for (block = block_stack; block; block = block->next)
886 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
888 if (block->data.block.stack_level != 0)
889 stack_level = block->data.block.stack_level;
890 /* Execute the cleanups for blocks we are exiting. */
891 if (block->data.block.cleanups != 0)
893 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
894 do_pending_stack_adjust ();
900 /* Ensure stack adjust isn't done by emit_jump, as this
901 would clobber the stack pointer. This one should be
902 deleted as dead by flow. */
903 clear_pending_stack_adjust ();
904 do_pending_stack_adjust ();
906 /* Don't do this adjust if it's to the end label and this function
907 is to return with a depressed stack pointer. */
908 if (label == return_label
909 && (((TREE_CODE (TREE_TYPE (current_function_decl))
911 && (TYPE_RETURNS_STACK_DEPRESSED
912 (TREE_TYPE (current_function_decl))))))
915 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
918 if (body != 0 && DECL_TOO_LATE (body))
919 error ("jump to `%s' invalidly jumps into binding contour",
920 IDENTIFIER_POINTER (DECL_NAME (body)));
922 /* Label not yet defined: may need to put this goto
923 on the fixup list. */
924 else if (! expand_fixup (body, label, last_insn))
926 /* No fixup needed. Record that the label is the target
927 of at least one goto that has no fixup. */
929 TREE_ADDRESSABLE (body) = 1;
935 /* Generate if necessary a fixup for a goto
936 whose target label in tree structure (if any) is TREE_LABEL
937 and whose target in rtl is RTL_LABEL.
939 If LAST_INSN is nonzero, we pretend that the jump appears
940 after insn LAST_INSN instead of at the current point in the insn stream.
942 The fixup will be used later to insert insns just before the goto.
943 Those insns will restore the stack level as appropriate for the
944 target label, and will (in the case of C++) also invoke any object
945 destructors which have to be invoked when we exit the scopes which
946 are exited by the goto.
948 Value is nonzero if a fixup is made. */
951 expand_fixup (tree_label, rtl_label, last_insn)
956 struct nesting *block, *end_block;
958 /* See if we can recognize which block the label will be output in.
959 This is possible in some very common cases.
960 If we succeed, set END_BLOCK to that block.
961 Otherwise, set it to 0. */
964 && (rtl_label == cond_stack->data.cond.endif_label
965 || rtl_label == cond_stack->data.cond.next_label))
966 end_block = cond_stack;
967 /* If we are in a loop, recognize certain labels which
968 are likely targets. This reduces the number of fixups
969 we need to create. */
971 && (rtl_label == loop_stack->data.loop.start_label
972 || rtl_label == loop_stack->data.loop.end_label
973 || rtl_label == loop_stack->data.loop.continue_label))
974 end_block = loop_stack;
978 /* Now set END_BLOCK to the binding level to which we will return. */
982 struct nesting *next_block = end_block->all;
985 /* First see if the END_BLOCK is inside the innermost binding level.
986 If so, then no cleanups or stack levels are relevant. */
987 while (next_block && next_block != block)
988 next_block = next_block->all;
993 /* Otherwise, set END_BLOCK to the innermost binding level
994 which is outside the relevant control-structure nesting. */
995 next_block = block_stack->next;
996 for (block = block_stack; block != end_block; block = block->all)
997 if (block == next_block)
998 next_block = next_block->next;
999 end_block = next_block;
1002 /* Does any containing block have a stack level or cleanups?
1003 If not, no fixup is needed, and that is the normal case
1004 (the only case, for standard C). */
1005 for (block = block_stack; block != end_block; block = block->next)
1006 if (block->data.block.stack_level != 0
1007 || block->data.block.cleanups != 0)
1010 if (block != end_block)
1012 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1013 struct goto_fixup *fixup
1014 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1015 /* In case an old stack level is restored, make sure that comes
1016 after any pending stack adjust. */
1017 /* ?? If the fixup isn't to come at the present position,
1018 doing the stack adjust here isn't useful. Doing it with our
1019 settings at that location isn't useful either. Let's hope
1022 do_pending_stack_adjust ();
1023 fixup->target = tree_label;
1024 fixup->target_rtl = rtl_label;
1026 /* Create a BLOCK node and a corresponding matched set of
1027 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1028 this point. The notes will encapsulate any and all fixup
1029 code which we might later insert at this point in the insn
1030 stream. Also, the BLOCK node will be the parent (i.e. the
1031 `SUPERBLOCK') of any other BLOCK nodes which we might create
1032 later on when we are expanding the fixup code.
1034 Note that optimization passes (including expand_end_loop)
1035 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1036 as a placeholder. */
1039 register rtx original_before_jump
1040 = last_insn ? last_insn : get_last_insn ();
1045 block = make_node (BLOCK);
1046 TREE_USED (block) = 1;
1048 if (!cfun->x_whole_function_mode_p)
1049 insert_block (block);
1053 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1054 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1059 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1060 if (cfun->x_whole_function_mode_p)
1061 NOTE_BLOCK (start) = block;
1062 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1063 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1064 if (cfun->x_whole_function_mode_p)
1065 NOTE_BLOCK (end) = block;
1066 fixup->context = block;
1068 emit_insns_after (start, original_before_jump);
1071 fixup->block_start_count = current_block_start_count;
1072 fixup->stack_level = 0;
1073 fixup->cleanup_list_list
1074 = ((block->data.block.outer_cleanups
1075 || block->data.block.cleanups)
1076 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1077 block->data.block.outer_cleanups)
1079 fixup->next = goto_fixup_chain;
1080 goto_fixup_chain = fixup;
1086 /* Expand any needed fixups in the outputmost binding level of the
1087 function. FIRST_INSN is the first insn in the function. */
1090 expand_fixups (first_insn)
1093 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1096 /* When exiting a binding contour, process all pending gotos requiring fixups.
1097 THISBLOCK is the structure that describes the block being exited.
1098 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1099 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1100 FIRST_INSN is the insn that began this contour.
1102 Gotos that jump out of this contour must restore the
1103 stack level and do the cleanups before actually jumping.
1105 DONT_JUMP_IN nonzero means report error there is a jump into this
1106 contour from before the beginning of the contour.
1107 This is also done if STACK_LEVEL is nonzero. */
1110 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1111 struct nesting *thisblock;
1117 register struct goto_fixup *f, *prev;
1119 /* F is the fixup we are considering; PREV is the previous one. */
1120 /* We run this loop in two passes so that cleanups of exited blocks
1121 are run first, and blocks that are exited are marked so
1124 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1126 /* Test for a fixup that is inactive because it is already handled. */
1127 if (f->before_jump == 0)
1129 /* Delete inactive fixup from the chain, if that is easy to do. */
1131 prev->next = f->next;
1133 /* Has this fixup's target label been defined?
1134 If so, we can finalize it. */
1135 else if (PREV_INSN (f->target_rtl) != 0)
1137 register rtx cleanup_insns;
1139 /* If this fixup jumped into this contour from before the beginning
1140 of this contour, report an error. This code used to use
1141 the first non-label insn after f->target_rtl, but that's
1142 wrong since such can be added, by things like put_var_into_stack
1143 and have INSN_UIDs that are out of the range of the block. */
1144 /* ??? Bug: this does not detect jumping in through intermediate
1145 blocks that have stack levels or cleanups.
1146 It detects only a problem with the innermost block
1147 around the label. */
1149 && (dont_jump_in || stack_level || cleanup_list)
1150 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1151 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1152 && ! DECL_ERROR_ISSUED (f->target))
1154 error_with_decl (f->target,
1155 "label `%s' used before containing binding contour");
1156 /* Prevent multiple errors for one label. */
1157 DECL_ERROR_ISSUED (f->target) = 1;
1160 /* We will expand the cleanups into a sequence of their own and
1161 then later on we will attach this new sequence to the insn
1162 stream just ahead of the actual jump insn. */
1166 /* Temporarily restore the lexical context where we will
1167 logically be inserting the fixup code. We do this for the
1168 sake of getting the debugging information right. */
1171 set_block (f->context);
1173 /* Expand the cleanups for blocks this jump exits. */
1174 if (f->cleanup_list_list)
1177 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1178 /* Marked elements correspond to blocks that have been closed.
1179 Do their cleanups. */
1180 if (TREE_ADDRESSABLE (lists)
1181 && TREE_VALUE (lists) != 0)
1183 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1184 /* Pop any pushes done in the cleanups,
1185 in case function is about to return. */
1186 do_pending_stack_adjust ();
1190 /* Restore stack level for the biggest contour that this
1191 jump jumps out of. */
1193 && ! (f->target_rtl == return_label
1194 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1196 && (TYPE_RETURNS_STACK_DEPRESSED
1197 (TREE_TYPE (current_function_decl))))))
1198 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1200 /* Finish up the sequence containing the insns which implement the
1201 necessary cleanups, and then attach that whole sequence to the
1202 insn stream just ahead of the actual jump insn. Attaching it
1203 at that point insures that any cleanups which are in fact
1204 implicit C++ object destructions (which must be executed upon
1205 leaving the block) appear (to the debugger) to be taking place
1206 in an area of the generated code where the object(s) being
1207 destructed are still "in scope". */
1209 cleanup_insns = get_insns ();
1213 emit_insns_after (cleanup_insns, f->before_jump);
1219 /* For any still-undefined labels, do the cleanups for this block now.
1220 We must do this now since items in the cleanup list may go out
1221 of scope when the block ends. */
1222 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1223 if (f->before_jump != 0
1224 && PREV_INSN (f->target_rtl) == 0
1225 /* Label has still not appeared. If we are exiting a block with
1226 a stack level to restore, that started before the fixup,
1227 mark this stack level as needing restoration
1228 when the fixup is later finalized. */
1230 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1231 means the label is undefined. That's erroneous, but possible. */
1232 && (thisblock->data.block.block_start_count
1233 <= f->block_start_count))
1235 tree lists = f->cleanup_list_list;
1238 for (; lists; lists = TREE_CHAIN (lists))
1239 /* If the following elt. corresponds to our containing block
1240 then the elt. must be for this block. */
1241 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1245 set_block (f->context);
1246 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1247 do_pending_stack_adjust ();
1248 cleanup_insns = get_insns ();
1251 if (cleanup_insns != 0)
1253 = emit_insns_after (cleanup_insns, f->before_jump);
1255 f->cleanup_list_list = TREE_CHAIN (lists);
1259 f->stack_level = stack_level;
1263 /* Return the number of times character C occurs in string S. */
1265 n_occurrences (c, s)
1275 /* Generate RTL for an asm statement (explicit assembler code).
1276 BODY is a STRING_CST node containing the assembler code text,
1277 or an ADDR_EXPR containing a STRING_CST. */
1283 if (current_function_check_memory_usage)
1285 error ("`asm' cannot be used in function where memory usage is checked");
1289 if (TREE_CODE (body) == ADDR_EXPR)
1290 body = TREE_OPERAND (body, 0);
1292 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1293 TREE_STRING_POINTER (body)));
1297 /* Generate RTL for an asm statement with arguments.
1298 STRING is the instruction template.
1299 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1300 Each output or input has an expression in the TREE_VALUE and
1301 a constraint-string in the TREE_PURPOSE.
1302 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1303 that is clobbered by this insn.
1305 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1306 Some elements of OUTPUTS may be replaced with trees representing temporary
1307 values. The caller should copy those temporary values to the originally
1310 VOL nonzero means the insn is volatile; don't optimize it. */
1313 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1314 tree string, outputs, inputs, clobbers;
1316 const char *filename;
1319 rtvec argvec, constraints;
1321 int ninputs = list_length (inputs);
1322 int noutputs = list_length (outputs);
1327 /* Vector of RTX's of evaluated output operands. */
1328 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1329 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1330 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1331 enum machine_mode *inout_mode
1332 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1333 /* The insn we have emitted. */
1335 int old_generating_concat_p = generating_concat_p;
1337 /* An ASM with no outputs needs to be treated as volatile, for now. */
1341 if (current_function_check_memory_usage)
1343 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1347 #ifdef MD_ASM_CLOBBERS
1348 /* Sometimes we wish to automatically clobber registers across an asm.
1349 Case in point is when the i386 backend moved from cc0 to a hard reg --
1350 maintaining source-level compatability means automatically clobbering
1351 the flags register. */
1352 MD_ASM_CLOBBERS (clobbers);
1355 if (current_function_check_memory_usage)
1357 error ("`asm' cannot be used in function where memory usage is checked");
1361 /* Count the number of meaningful clobbered registers, ignoring what
1362 we would ignore later. */
1364 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1366 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1368 i = decode_reg_name (regname);
1369 if (i >= 0 || i == -4)
1372 error ("unknown register name `%s' in `asm'", regname);
1377 /* Check that the number of alternatives is constant across all
1379 if (outputs || inputs)
1381 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1382 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1385 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1387 error ("too many alternatives in `asm'");
1394 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1396 if (n_occurrences (',', constraint) != nalternatives)
1398 error ("operand constraints for `asm' differ in number of alternatives");
1402 if (TREE_CHAIN (tmp))
1403 tmp = TREE_CHAIN (tmp);
1405 tmp = next, next = 0;
1409 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1411 tree val = TREE_VALUE (tail);
1412 tree type = TREE_TYPE (val);
1413 const char *constraint;
1421 /* If there's an erroneous arg, emit no insn. */
1422 if (TREE_TYPE (val) == error_mark_node)
1425 /* Make sure constraint has `=' and does not have `+'. Also, see
1426 if it allows any register. Be liberal on the latter test, since
1427 the worst that happens if we get it wrong is we issue an error
1430 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1431 c_len = strlen (constraint);
1433 /* Allow the `=' or `+' to not be at the beginning of the string,
1434 since it wasn't explicitly documented that way, and there is a
1435 large body of code that puts it last. Swap the character to
1436 the front, so as not to uglify any place else. */
1440 if ((p = strchr (constraint, '=')) != NULL)
1442 if ((p = strchr (constraint, '+')) != NULL)
1445 error ("output operand constraint lacks `='");
1449 is_inout = *p == '+';
1453 /* Have to throw away this constraint string and get a new one. */
1454 char *buf = alloca (c_len + 1);
1457 memcpy (buf + 1, constraint, j);
1458 memcpy (buf + 1 + j, p + 1, c_len - j); /* not -j-1 - copy null */
1459 constraint = ggc_alloc_string (buf, c_len);
1463 "output constraint `%c' for operand %d is not at the beginning",
1467 /* Make sure we can specify the matching operand. */
1468 if (is_inout && i > 9)
1470 error ("output operand constraint %d contains `+'", i);
1474 for (j = 1; j < c_len; j++)
1475 switch (constraint[j])
1479 error ("operand constraint contains '+' or '=' at illegal position.");
1483 if (i + 1 == ninputs + noutputs)
1485 error ("`%%' constraint used with last operand");
1490 case '?': case '!': case '*': case '&': case '#':
1491 case 'E': case 'F': case 'G': case 'H':
1492 case 's': case 'i': case 'n':
1493 case 'I': case 'J': case 'K': case 'L': case 'M':
1494 case 'N': case 'O': case 'P': case ',':
1497 case '0': case '1': case '2': case '3': case '4':
1498 case '5': case '6': case '7': case '8': case '9':
1499 error ("matching constraint not valid in output operand");
1502 case 'V': case 'm': case 'o':
1507 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1508 excepting those that expand_call created. So match memory
1523 if (! ISALPHA (constraint[j]))
1525 error ("invalid punctuation `%c' in constraint",
1529 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1531 #ifdef EXTRA_CONSTRAINT
1534 /* Otherwise we can't assume anything about the nature of
1535 the constraint except that it isn't purely registers.
1536 Treat it like "g" and hope for the best. */
1544 /* If an output operand is not a decl or indirect ref and our constraint
1545 allows a register, make a temporary to act as an intermediate.
1546 Make the asm insn write into that, then our caller will copy it to
1547 the real output operand. Likewise for promoted variables. */
1549 generating_concat_p = 0;
1551 real_output_rtx[i] = NULL_RTX;
1552 if ((TREE_CODE (val) == INDIRECT_REF
1555 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1556 && ! (GET_CODE (DECL_RTL (val)) == REG
1557 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1562 mark_addressable (TREE_VALUE (tail));
1565 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1566 EXPAND_MEMORY_USE_WO);
1568 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1569 error ("output number %d not directly addressable", i);
1570 if ((! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1571 || GET_CODE (output_rtx[i]) == CONCAT)
1573 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1574 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1576 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1581 output_rtx[i] = assign_temp (type, 0, 0, 1);
1582 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1585 generating_concat_p = old_generating_concat_p;
1589 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1590 inout_opnum[ninout++] = i;
1595 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1597 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1601 /* Make vectors for the expression-rtx and constraint strings. */
1603 argvec = rtvec_alloc (ninputs);
1604 constraints = rtvec_alloc (ninputs);
1606 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
1607 : GET_MODE (output_rtx[0])),
1608 TREE_STRING_POINTER (string),
1609 empty_string, 0, argvec, constraints,
1612 MEM_VOLATILE_P (body) = vol;
1614 /* Eval the inputs and put them into ARGVEC.
1615 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1618 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1621 int allows_reg = 0, allows_mem = 0;
1622 const char *constraint, *orig_constraint;
1626 /* If there's an erroneous arg, emit no insn,
1627 because the ASM_INPUT would get VOIDmode
1628 and that could cause a crash in reload. */
1629 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1632 /* ??? Can this happen, and does the error message make any sense? */
1633 if (TREE_PURPOSE (tail) == NULL_TREE)
1635 error ("hard register `%s' listed as input operand to `asm'",
1636 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1640 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1641 c_len = strlen (constraint);
1642 orig_constraint = constraint;
1644 /* Make sure constraint has neither `=', `+', nor '&'. */
1646 for (j = 0; j < c_len; j++)
1647 switch (constraint[j])
1649 case '+': case '=': case '&':
1650 if (constraint == orig_constraint)
1652 error ("input operand constraint contains `%c'",
1659 if (constraint == orig_constraint
1660 && i + 1 == ninputs - ninout)
1662 error ("`%%' constraint used with last operand");
1667 case 'V': case 'm': case 'o':
1672 case '?': case '!': case '*': case '#':
1673 case 'E': case 'F': case 'G': case 'H':
1674 case 's': case 'i': case 'n':
1675 case 'I': case 'J': case 'K': case 'L': case 'M':
1676 case 'N': case 'O': case 'P': case ',':
1679 /* Whether or not a numeric constraint allows a register is
1680 decided by the matching constraint, and so there is no need
1681 to do anything special with them. We must handle them in
1682 the default case, so that we don't unnecessarily force
1683 operands to memory. */
1684 case '0': case '1': case '2': case '3': case '4':
1685 case '5': case '6': case '7': case '8': case '9':
1686 if (constraint[j] >= '0' + noutputs)
1689 ("matching constraint references invalid operand number");
1693 /* Try and find the real constraint for this dup. */
1694 if ((j == 0 && c_len == 1)
1695 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1699 for (j = constraint[j] - '0'; j > 0; --j)
1702 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1703 c_len = strlen (constraint);
1720 if (! ISALPHA (constraint[j]))
1722 error ("invalid punctuation `%c' in constraint",
1726 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1728 #ifdef EXTRA_CONSTRAINT
1731 /* Otherwise we can't assume anything about the nature of
1732 the constraint except that it isn't purely registers.
1733 Treat it like "g" and hope for the best. */
1741 if (! allows_reg && allows_mem)
1742 mark_addressable (TREE_VALUE (tail));
1744 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1746 /* Never pass a CONCAT to an ASM. */
1747 generating_concat_p = 0;
1748 if (GET_CODE (op) == CONCAT)
1749 op = force_reg (GET_MODE (op), op);
1751 if (asm_operand_ok (op, constraint) <= 0)
1754 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1755 else if (!allows_mem)
1756 warning ("asm operand %d probably doesn't match constraints", i);
1757 else if (CONSTANT_P (op))
1758 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1760 else if (GET_CODE (op) == REG
1761 || GET_CODE (op) == SUBREG
1762 || GET_CODE (op) == CONCAT)
1764 tree type = TREE_TYPE (TREE_VALUE (tail));
1765 rtx memloc = assign_temp (type, 1, 1, 1);
1767 emit_move_insn (memloc, op);
1771 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1772 /* We won't recognize volatile memory as available a
1773 memory_operand at this point. Ignore it. */
1775 else if (queued_subexp_p (op))
1778 /* ??? Leave this only until we have experience with what
1779 happens in combine and elsewhere when constraints are
1781 warning ("asm operand %d probably doesn't match constraints", i);
1783 generating_concat_p = old_generating_concat_p;
1784 ASM_OPERANDS_INPUT (body, i) = op;
1786 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
1787 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1792 /* Protect all the operands from the queue now that they have all been
1795 generating_concat_p = 0;
1797 for (i = 0; i < ninputs - ninout; i++)
1798 ASM_OPERANDS_INPUT (body, i)
1799 = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);
1801 for (i = 0; i < noutputs; i++)
1802 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1804 /* For in-out operands, copy output rtx to input rtx. */
1805 for (i = 0; i < ninout; i++)
1807 int j = inout_opnum[i];
1809 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
1811 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
1812 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1815 generating_concat_p = old_generating_concat_p;
1817 /* Now, for each output, construct an rtx
1818 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1819 ARGVEC CONSTRAINTS))
1820 If there is more than one, put them inside a PARALLEL. */
1822 if (noutputs == 1 && nclobbers == 0)
1824 ASM_OPERANDS_OUTPUT_CONSTRAINT (body)
1825 = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1826 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1829 else if (noutputs == 0 && nclobbers == 0)
1831 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1832 insn = emit_insn (body);
1843 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1845 /* For each output operand, store a SET. */
1846 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1848 XVECEXP (body, 0, i)
1849 = gen_rtx_SET (VOIDmode,
1851 gen_rtx_ASM_OPERANDS
1852 (GET_MODE (output_rtx[i]),
1853 TREE_STRING_POINTER (string),
1854 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1855 i, argvec, constraints,
1858 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1861 /* If there are no outputs (but there are some clobbers)
1862 store the bare ASM_OPERANDS into the PARALLEL. */
1865 XVECEXP (body, 0, i++) = obody;
1867 /* Store (clobber REG) for each clobbered register specified. */
1869 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1871 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1872 int j = decode_reg_name (regname);
1876 if (j == -3) /* `cc', which is not a register */
1879 if (j == -4) /* `memory', don't cache memory across asm */
1881 XVECEXP (body, 0, i++)
1882 = gen_rtx_CLOBBER (VOIDmode,
1885 gen_rtx_SCRATCH (VOIDmode)));
1889 /* Ignore unknown register, error already signaled. */
1893 /* Use QImode since that's guaranteed to clobber just one reg. */
1894 XVECEXP (body, 0, i++)
1895 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1898 insn = emit_insn (body);
1901 /* For any outputs that needed reloading into registers, spill them
1902 back to where they belong. */
1903 for (i = 0; i < noutputs; ++i)
1904 if (real_output_rtx[i])
1905 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1910 /* Generate RTL to evaluate the expression EXP
1911 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1914 expand_expr_stmt (exp)
1917 /* If -W, warn about statements with no side effects,
1918 except for an explicit cast to void (e.g. for assert()), and
1919 except inside a ({...}) where they may be useful. */
1920 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1922 if (! TREE_SIDE_EFFECTS (exp))
1924 if ((extra_warnings || warn_unused_value)
1925 && !(TREE_CODE (exp) == CONVERT_EXPR
1926 && VOID_TYPE_P (TREE_TYPE (exp))))
1927 warning_with_file_and_line (emit_filename, emit_lineno,
1928 "statement with no effect");
1930 else if (warn_unused_value)
1931 warn_if_unused_value (exp);
1934 /* If EXP is of function type and we are expanding statements for
1935 value, convert it to pointer-to-function. */
1936 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1937 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1939 /* The call to `expand_expr' could cause last_expr_type and
1940 last_expr_value to get reset. Therefore, we set last_expr_value
1941 and last_expr_type *after* calling expand_expr. */
1942 last_expr_value = expand_expr (exp,
1943 (expr_stmts_for_value
1944 ? NULL_RTX : const0_rtx),
1946 last_expr_type = TREE_TYPE (exp);
1948 /* If all we do is reference a volatile value in memory,
1949 copy it to a register to be sure it is actually touched. */
1950 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1951 && TREE_THIS_VOLATILE (exp))
1953 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1955 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1956 copy_to_reg (last_expr_value);
1959 rtx lab = gen_label_rtx ();
1961 /* Compare the value with itself to reference it. */
1962 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1963 expand_expr (TYPE_SIZE (last_expr_type),
1964 NULL_RTX, VOIDmode, 0),
1966 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1972 /* If this expression is part of a ({...}) and is in memory, we may have
1973 to preserve temporaries. */
1974 preserve_temp_slots (last_expr_value);
1976 /* Free any temporaries used to evaluate this expression. Any temporary
1977 used as a result of this expression will already have been preserved
1984 /* Warn if EXP contains any computations whose results are not used.
1985 Return 1 if a warning is printed; 0 otherwise. */
1988 warn_if_unused_value (exp)
1991 if (TREE_USED (exp))
1994 /* Don't warn about void constructs. This includes casting to void,
1995 void function calls, and statement expressions with a final cast
1997 if (VOID_TYPE_P (TREE_TYPE (exp)))
2000 switch (TREE_CODE (exp))
2002 case PREINCREMENT_EXPR:
2003 case POSTINCREMENT_EXPR:
2004 case PREDECREMENT_EXPR:
2005 case POSTDECREMENT_EXPR:
2010 case METHOD_CALL_EXPR:
2012 case TRY_CATCH_EXPR:
2013 case WITH_CLEANUP_EXPR:
2018 /* For a binding, warn if no side effect within it. */
2019 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2022 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2024 case TRUTH_ORIF_EXPR:
2025 case TRUTH_ANDIF_EXPR:
2026 /* In && or ||, warn if 2nd operand has no side effect. */
2027 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2030 if (TREE_NO_UNUSED_WARNING (exp))
2032 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
2034 /* Let people do `(foo (), 0)' without a warning. */
2035 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2037 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2041 case NON_LVALUE_EXPR:
2042 /* Don't warn about conversions not explicit in the user's program. */
2043 if (TREE_NO_UNUSED_WARNING (exp))
2045 /* Assignment to a cast usually results in a cast of a modify.
2046 Don't complain about that. There can be an arbitrary number of
2047 casts before the modify, so we must loop until we find the first
2048 non-cast expression and then test to see if that is a modify. */
2050 tree tem = TREE_OPERAND (exp, 0);
2052 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2053 tem = TREE_OPERAND (tem, 0);
2055 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2056 || TREE_CODE (tem) == CALL_EXPR)
2062 /* Don't warn about automatic dereferencing of references, since
2063 the user cannot control it. */
2064 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2065 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2069 /* Referencing a volatile value is a side effect, so don't warn. */
2071 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2072 && TREE_THIS_VOLATILE (exp))
2075 /* If this is an expression with side effects, don't warn. */
2076 if (TREE_SIDE_EFFECTS (exp))
2079 /* If this is an expression which has no operands, there is no value
2080 to be unused. There are no such language-independent codes,
2081 but front ends may define such. */
2082 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2083 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2087 warning_with_file_and_line (emit_filename, emit_lineno,
2088 "value computed is not used");
2093 /* Clear out the memory of the last expression evaluated. */
2101 /* Begin a statement which will return a value.
2102 Return the RTL_EXPR for this statement expr.
2103 The caller must save that value and pass it to expand_end_stmt_expr. */
2106 expand_start_stmt_expr ()
2110 /* Make the RTL_EXPR node temporary, not momentary,
2111 so that rtl_expr_chain doesn't become garbage. */
2112 t = make_node (RTL_EXPR);
2113 do_pending_stack_adjust ();
2114 start_sequence_for_rtl_expr (t);
2116 expr_stmts_for_value++;
2120 /* Restore the previous state at the end of a statement that returns a value.
2121 Returns a tree node representing the statement's value and the
2122 insns to compute the value.
2124 The nodes of that expression have been freed by now, so we cannot use them.
2125 But we don't want to do that anyway; the expression has already been
2126 evaluated and now we just want to use the value. So generate a RTL_EXPR
2127 with the proper type and RTL value.
2129 If the last substatement was not an expression,
2130 return something with type `void'. */
2133 expand_end_stmt_expr (t)
2138 if (last_expr_type == 0)
2140 last_expr_type = void_type_node;
2141 last_expr_value = const0_rtx;
2143 else if (last_expr_value == 0)
2144 /* There are some cases where this can happen, such as when the
2145 statement is void type. */
2146 last_expr_value = const0_rtx;
2147 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2148 /* Remove any possible QUEUED. */
2149 last_expr_value = protect_from_queue (last_expr_value, 0);
2153 TREE_TYPE (t) = last_expr_type;
2154 RTL_EXPR_RTL (t) = last_expr_value;
2155 RTL_EXPR_SEQUENCE (t) = get_insns ();
2157 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2161 /* Don't consider deleting this expr or containing exprs at tree level. */
2162 TREE_SIDE_EFFECTS (t) = 1;
2163 /* Propagate volatility of the actual RTL expr. */
2164 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2167 expr_stmts_for_value--;
2172 /* Generate RTL for the start of an if-then. COND is the expression
2173 whose truth should be tested.
2175 If EXITFLAG is nonzero, this conditional is visible to
2176 `exit_something'. */
2179 expand_start_cond (cond, exitflag)
2183 struct nesting *thiscond = ALLOC_NESTING ();
2185 /* Make an entry on cond_stack for the cond we are entering. */
2187 thiscond->next = cond_stack;
2188 thiscond->all = nesting_stack;
2189 thiscond->depth = ++nesting_depth;
2190 thiscond->data.cond.next_label = gen_label_rtx ();
2191 /* Before we encounter an `else', we don't need a separate exit label
2192 unless there are supposed to be exit statements
2193 to exit this conditional. */
2194 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2195 thiscond->data.cond.endif_label = thiscond->exit_label;
2196 cond_stack = thiscond;
2197 nesting_stack = thiscond;
2199 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2202 /* Generate RTL between then-clause and the elseif-clause
2203 of an if-then-elseif-.... */
2206 expand_start_elseif (cond)
2209 if (cond_stack->data.cond.endif_label == 0)
2210 cond_stack->data.cond.endif_label = gen_label_rtx ();
2211 emit_jump (cond_stack->data.cond.endif_label);
2212 emit_label (cond_stack->data.cond.next_label);
2213 cond_stack->data.cond.next_label = gen_label_rtx ();
2214 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2217 /* Generate RTL between the then-clause and the else-clause
2218 of an if-then-else. */
2221 expand_start_else ()
2223 if (cond_stack->data.cond.endif_label == 0)
2224 cond_stack->data.cond.endif_label = gen_label_rtx ();
2226 emit_jump (cond_stack->data.cond.endif_label);
2227 emit_label (cond_stack->data.cond.next_label);
2228 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2231 /* After calling expand_start_else, turn this "else" into an "else if"
2232 by providing another condition. */
2235 expand_elseif (cond)
2238 cond_stack->data.cond.next_label = gen_label_rtx ();
2239 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2242 /* Generate RTL for the end of an if-then.
2243 Pop the record for it off of cond_stack. */
2248 struct nesting *thiscond = cond_stack;
2250 do_pending_stack_adjust ();
2251 if (thiscond->data.cond.next_label)
2252 emit_label (thiscond->data.cond.next_label);
2253 if (thiscond->data.cond.endif_label)
2254 emit_label (thiscond->data.cond.endif_label);
2256 POPSTACK (cond_stack);
2260 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2261 loop should be exited by `exit_something'. This is a loop for which
2262 `expand_continue' will jump to the top of the loop.
2264 Make an entry on loop_stack to record the labels associated with
2268 expand_start_loop (exit_flag)
2271 register struct nesting *thisloop = ALLOC_NESTING ();
2273 /* Make an entry on loop_stack for the loop we are entering. */
2275 thisloop->next = loop_stack;
2276 thisloop->all = nesting_stack;
2277 thisloop->depth = ++nesting_depth;
2278 thisloop->data.loop.start_label = gen_label_rtx ();
2279 thisloop->data.loop.end_label = gen_label_rtx ();
2280 thisloop->data.loop.alt_end_label = 0;
2281 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2282 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2283 loop_stack = thisloop;
2284 nesting_stack = thisloop;
2286 do_pending_stack_adjust ();
2288 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2289 emit_label (thisloop->data.loop.start_label);
2294 /* Like expand_start_loop but for a loop where the continuation point
2295 (for expand_continue_loop) will be specified explicitly. */
2298 expand_start_loop_continue_elsewhere (exit_flag)
2301 struct nesting *thisloop = expand_start_loop (exit_flag);
2302 loop_stack->data.loop.continue_label = gen_label_rtx ();
2306 /* Begin a null, aka do { } while (0) "loop". But since the contents
2307 of said loop can still contain a break, we must frob the loop nest. */
2310 expand_start_null_loop ()
2312 register struct nesting *thisloop = ALLOC_NESTING ();
2314 /* Make an entry on loop_stack for the loop we are entering. */
2316 thisloop->next = loop_stack;
2317 thisloop->all = nesting_stack;
2318 thisloop->depth = ++nesting_depth;
2319 thisloop->data.loop.start_label = emit_note (NULL, NOTE_INSN_DELETED);
2320 thisloop->data.loop.end_label = gen_label_rtx ();
2321 thisloop->data.loop.alt_end_label = NULL_RTX;
2322 thisloop->data.loop.continue_label = thisloop->data.loop.end_label;
2323 thisloop->exit_label = thisloop->data.loop.end_label;
2324 loop_stack = thisloop;
2325 nesting_stack = thisloop;
2330 /* Specify the continuation point for a loop started with
2331 expand_start_loop_continue_elsewhere.
2332 Use this at the point in the code to which a continue statement
2336 expand_loop_continue_here ()
2338 do_pending_stack_adjust ();
2339 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2340 emit_label (loop_stack->data.loop.continue_label);
2343 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2344 Pop the block off of loop_stack. */
2349 rtx start_label = loop_stack->data.loop.start_label;
2350 rtx insn = get_last_insn ();
2351 int needs_end_jump = 1;
2353 /* Mark the continue-point at the top of the loop if none elsewhere. */
2354 if (start_label == loop_stack->data.loop.continue_label)
2355 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2357 do_pending_stack_adjust ();
2359 /* If optimizing, perhaps reorder the loop.
2360 First, try to use a condjump near the end.
2361 expand_exit_loop_if_false ends loops with unconditional jumps,
2364 if (test) goto label;
2366 goto loop_stack->data.loop.end_label
2370 If we find such a pattern, we can end the loop earlier. */
2373 && GET_CODE (insn) == CODE_LABEL
2374 && LABEL_NAME (insn) == NULL
2375 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2378 rtx jump = PREV_INSN (PREV_INSN (label));
2380 if (GET_CODE (jump) == JUMP_INSN
2381 && GET_CODE (PATTERN (jump)) == SET
2382 && SET_DEST (PATTERN (jump)) == pc_rtx
2383 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2384 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2385 == loop_stack->data.loop.end_label))
2389 /* The test might be complex and reference LABEL multiple times,
2390 like the loop in loop_iterations to set vtop. To handle this,
2392 insn = PREV_INSN (label);
2393 reorder_insns (label, label, start_label);
2395 for (prev = PREV_INSN (jump);; prev = PREV_INSN (prev))
2397 /* We ignore line number notes, but if we see any other note,
2398 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2399 NOTE_INSN_LOOP_*, we disable this optimization. */
2400 if (GET_CODE (prev) == NOTE)
2402 if (NOTE_LINE_NUMBER (prev) < 0)
2406 if (GET_CODE (prev) == CODE_LABEL)
2408 if (GET_CODE (prev) == JUMP_INSN)
2410 if (GET_CODE (PATTERN (prev)) == SET
2411 && SET_DEST (PATTERN (prev)) == pc_rtx
2412 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2413 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2415 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2417 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2419 emit_note_after (NOTE_INSN_LOOP_END, prev);
2428 /* If the loop starts with a loop exit, roll that to the end where
2429 it will optimize together with the jump back.
2431 We look for the conditional branch to the exit, except that once
2432 we find such a branch, we don't look past 30 instructions.
2434 In more detail, if the loop presently looks like this (in pseudo-C):
2437 if (test) goto end_label;
2442 transform it to look like:
2448 if (test) goto end_label;
2449 goto newstart_label;
2452 Here, the `test' may actually consist of some reasonably complex
2453 code, terminating in a test. */
2458 ! (GET_CODE (insn) == JUMP_INSN
2459 && GET_CODE (PATTERN (insn)) == SET
2460 && SET_DEST (PATTERN (insn)) == pc_rtx
2461 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2465 rtx last_test_insn = NULL_RTX;
2467 /* Scan insns from the top of the loop looking for a qualified
2468 conditional exit. */
2469 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2470 insn = NEXT_INSN (insn))
2472 if (GET_CODE (insn) == NOTE)
2475 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2476 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2477 /* The code that actually moves the exit test will
2478 carefully leave BLOCK notes in their original
2479 location. That means, however, that we can't debug
2480 the exit test itself. So, we refuse to move code
2481 containing BLOCK notes at low optimization levels. */
2484 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2486 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2490 /* We've come to the end of an EH region, but
2491 never saw the beginning of that region. That
2492 means that an EH region begins before the top
2493 of the loop, and ends in the middle of it. The
2494 existence of such a situation violates a basic
2495 assumption in this code, since that would imply
2496 that even when EH_REGIONS is zero, we might
2497 move code out of an exception region. */
2501 /* We must not walk into a nested loop. */
2502 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2505 /* We already know this INSN is a NOTE, so there's no
2506 point in looking at it to see if it's a JUMP. */
2510 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2513 if (last_test_insn && num_insns > 30)
2517 /* We don't want to move a partial EH region. Consider:
2531 This isn't legal C++, but here's what it's supposed to
2532 mean: if cond() is true, stop looping. Otherwise,
2533 call bar, and keep looping. In addition, if cond
2534 throws an exception, catch it and keep looping. Such
2535 constructs are certainy legal in LISP.
2537 We should not move the `if (cond()) 0' test since then
2538 the EH-region for the try-block would be broken up.
2539 (In this case we would the EH_BEG note for the `try'
2540 and `if cond()' but not the call to bar() or the
2543 So we don't look for tests within an EH region. */
2546 if (GET_CODE (insn) == JUMP_INSN
2547 && GET_CODE (PATTERN (insn)) == SET
2548 && SET_DEST (PATTERN (insn)) == pc_rtx)
2550 /* This is indeed a jump. */
2551 rtx dest1 = NULL_RTX;
2552 rtx dest2 = NULL_RTX;
2553 rtx potential_last_test;
2554 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2556 /* A conditional jump. */
2557 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2558 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2559 potential_last_test = insn;
2563 /* An unconditional jump. */
2564 dest1 = SET_SRC (PATTERN (insn));
2565 /* Include the BARRIER after the JUMP. */
2566 potential_last_test = NEXT_INSN (insn);
2570 if (dest1 && GET_CODE (dest1) == LABEL_REF
2571 && ((XEXP (dest1, 0)
2572 == loop_stack->data.loop.alt_end_label)
2574 == loop_stack->data.loop.end_label)))
2576 last_test_insn = potential_last_test;
2580 /* If this was a conditional jump, there may be
2581 another label at which we should look. */
2588 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2590 /* We found one. Move everything from there up
2591 to the end of the loop, and add a jump into the loop
2592 to jump to there. */
2593 register rtx newstart_label = gen_label_rtx ();
2594 register rtx start_move = start_label;
2597 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2598 then we want to move this note also. */
2599 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2600 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2601 == NOTE_INSN_LOOP_CONT))
2602 start_move = PREV_INSN (start_move);
2604 emit_label_after (newstart_label, PREV_INSN (start_move));
2606 /* Actually move the insns. Start at the beginning, and
2607 keep copying insns until we've copied the
2609 for (insn = start_move; insn; insn = next_insn)
2611 /* Figure out which insn comes after this one. We have
2612 to do this before we move INSN. */
2613 if (insn == last_test_insn)
2614 /* We've moved all the insns. */
2615 next_insn = NULL_RTX;
2617 next_insn = NEXT_INSN (insn);
2619 if (GET_CODE (insn) == NOTE
2620 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2621 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2622 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2623 NOTE_INSN_BLOCK_ENDs because the correct generation
2624 of debugging information depends on these appearing
2625 in the same order in the RTL and in the tree
2626 structure, where they are represented as BLOCKs.
2627 So, we don't move block notes. Of course, moving
2628 the code inside the block is likely to make it
2629 impossible to debug the instructions in the exit
2630 test, but such is the price of optimization. */
2633 /* Move the INSN. */
2634 reorder_insns (insn, insn, get_last_insn ());
2637 emit_jump_insn_after (gen_jump (start_label),
2638 PREV_INSN (newstart_label));
2639 emit_barrier_after (PREV_INSN (newstart_label));
2640 start_label = newstart_label;
2646 emit_jump (start_label);
2647 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2649 emit_label (loop_stack->data.loop.end_label);
2651 POPSTACK (loop_stack);
2656 /* Finish a null loop, aka do { } while (0). */
2659 expand_end_null_loop ()
2661 do_pending_stack_adjust ();
2662 emit_label (loop_stack->data.loop.end_label);
2664 POPSTACK (loop_stack);
2669 /* Generate a jump to the current loop's continue-point.
2670 This is usually the top of the loop, but may be specified
2671 explicitly elsewhere. If not currently inside a loop,
2672 return 0 and do nothing; caller will print an error message. */
2675 expand_continue_loop (whichloop)
2676 struct nesting *whichloop;
2680 whichloop = loop_stack;
2683 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2688 /* Generate a jump to exit the current loop. If not currently inside a loop,
2689 return 0 and do nothing; caller will print an error message. */
2692 expand_exit_loop (whichloop)
2693 struct nesting *whichloop;
2697 whichloop = loop_stack;
2700 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2704 /* Generate a conditional jump to exit the current loop if COND
2705 evaluates to zero. If not currently inside a loop,
2706 return 0 and do nothing; caller will print an error message. */
2709 expand_exit_loop_if_false (whichloop, cond)
2710 struct nesting *whichloop;
2713 rtx label = gen_label_rtx ();
2718 whichloop = loop_stack;
2721 /* In order to handle fixups, we actually create a conditional jump
2722 around a unconditional branch to exit the loop. If fixups are
2723 necessary, they go before the unconditional branch. */
2725 do_jump (cond, NULL_RTX, label);
2726 last_insn = get_last_insn ();
2727 if (GET_CODE (last_insn) == CODE_LABEL)
2728 whichloop->data.loop.alt_end_label = last_insn;
2729 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2736 /* Return nonzero if the loop nest is empty. Else return zero. */
2739 stmt_loop_nest_empty ()
2741 /* cfun->stmt can be NULL if we are building a call to get the
2742 EH context for a setjmp/longjmp EH target and the current
2743 function was a deferred inline function. */
2744 return (cfun->stmt == NULL || loop_stack == NULL);
2747 /* Return non-zero if we should preserve sub-expressions as separate
2748 pseudos. We never do so if we aren't optimizing. We always do so
2749 if -fexpensive-optimizations.
2751 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2752 the loop may still be a small one. */
2755 preserve_subexpressions_p ()
2759 if (flag_expensive_optimizations)
2762 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2765 insn = get_last_insn_anywhere ();
2768 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2769 < n_non_fixed_regs * 3));
2773 /* Generate a jump to exit the current loop, conditional, binding contour
2774 or case statement. Not all such constructs are visible to this function,
2775 only those started with EXIT_FLAG nonzero. Individual languages use
2776 the EXIT_FLAG parameter to control which kinds of constructs you can
2779 If not currently inside anything that can be exited,
2780 return 0 and do nothing; caller will print an error message. */
2783 expand_exit_something ()
2787 for (n = nesting_stack; n; n = n->all)
2788 if (n->exit_label != 0)
2790 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2797 /* Generate RTL to return from the current function, with no value.
2798 (That is, we do not do anything about returning any value.) */
2801 expand_null_return ()
2803 struct nesting *block = block_stack;
2804 rtx last_insn = get_last_insn ();
2806 /* If this function was declared to return a value, but we
2807 didn't, clobber the return registers so that they are not
2808 propogated live to the rest of the function. */
2809 clobber_return_register ();
2811 /* Does any pending block have cleanups? */
2812 while (block && block->data.block.cleanups == 0)
2813 block = block->next;
2815 /* If yes, use a goto to return, since that runs cleanups. */
2817 expand_null_return_1 (last_insn, block != 0);
2820 /* Generate RTL to return from the current function, with value VAL. */
2823 expand_value_return (val)
2826 struct nesting *block = block_stack;
2827 rtx last_insn = get_last_insn ();
2828 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2830 /* Copy the value to the return location
2831 unless it's already there. */
2833 if (return_reg != val)
2835 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2836 #ifdef PROMOTE_FUNCTION_RETURN
2837 int unsignedp = TREE_UNSIGNED (type);
2838 enum machine_mode old_mode
2839 = DECL_MODE (DECL_RESULT (current_function_decl));
2840 enum machine_mode mode
2841 = promote_mode (type, old_mode, &unsignedp, 1);
2843 if (mode != old_mode)
2844 val = convert_modes (mode, old_mode, val, unsignedp);
2846 if (GET_CODE (return_reg) == PARALLEL)
2847 emit_group_load (return_reg, val, int_size_in_bytes (type),
2850 emit_move_insn (return_reg, val);
2853 /* Does any pending block have cleanups? */
2855 while (block && block->data.block.cleanups == 0)
2856 block = block->next;
2858 /* If yes, use a goto to return, since that runs cleanups.
2859 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2861 expand_null_return_1 (last_insn, block != 0);
2864 /* Output a return with no value. If LAST_INSN is nonzero,
2865 pretend that the return takes place after LAST_INSN.
2866 If USE_GOTO is nonzero then don't use a return instruction;
2867 go to the return label instead. This causes any cleanups
2868 of pending blocks to be executed normally. */
2871 expand_null_return_1 (last_insn, use_goto)
2875 rtx end_label = cleanup_label ? cleanup_label : return_label;
2877 clear_pending_stack_adjust ();
2878 do_pending_stack_adjust ();
2881 /* PCC-struct return always uses an epilogue. */
2882 if (current_function_returns_pcc_struct || use_goto)
2885 end_label = return_label = gen_label_rtx ();
2886 expand_goto_internal (NULL_TREE, end_label, last_insn);
2890 /* Otherwise output a simple return-insn if one is available,
2891 unless it won't do the job. */
2893 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2895 emit_jump_insn (gen_return ());
2901 /* Otherwise jump to the epilogue. */
2902 expand_goto_internal (NULL_TREE, end_label, last_insn);
2905 /* Generate RTL to evaluate the expression RETVAL and return it
2906 from the current function. */
2909 expand_return (retval)
2912 /* If there are any cleanups to be performed, then they will
2913 be inserted following LAST_INSN. It is desirable
2914 that the last_insn, for such purposes, should be the
2915 last insn before computing the return value. Otherwise, cleanups
2916 which call functions can clobber the return value. */
2917 /* ??? rms: I think that is erroneous, because in C++ it would
2918 run destructors on variables that might be used in the subsequent
2919 computation of the return value. */
2921 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2922 register rtx val = 0;
2926 /* If function wants no value, give it none. */
2927 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2929 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2931 expand_null_return ();
2935 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2936 /* This is not sufficient. We also need to watch for cleanups of the
2937 expression we are about to expand. Unfortunately, we cannot know
2938 if it has cleanups until we expand it, and we want to change how we
2939 expand it depending upon if we need cleanups. We can't win. */
2941 cleanups = any_pending_cleanups (1);
2946 if (retval == error_mark_node)
2947 retval_rhs = NULL_TREE;
2948 else if (TREE_CODE (retval) == RESULT_DECL)
2949 retval_rhs = retval;
2950 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2951 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2952 retval_rhs = TREE_OPERAND (retval, 1);
2953 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2954 /* Recognize tail-recursive call to void function. */
2955 retval_rhs = retval;
2957 retval_rhs = NULL_TREE;
2959 /* Only use `last_insn' if there are cleanups which must be run. */
2960 if (cleanups || cleanup_label != 0)
2961 last_insn = get_last_insn ();
2963 /* Distribute return down conditional expr if either of the sides
2964 may involve tail recursion (see test below). This enhances the number
2965 of tail recursions we see. Don't do this always since it can produce
2966 sub-optimal code in some cases and we distribute assignments into
2967 conditional expressions when it would help. */
2969 if (optimize && retval_rhs != 0
2970 && frame_offset == 0
2971 && TREE_CODE (retval_rhs) == COND_EXPR
2972 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2973 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2975 rtx label = gen_label_rtx ();
2978 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2979 start_cleanup_deferral ();
2980 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2981 DECL_RESULT (current_function_decl),
2982 TREE_OPERAND (retval_rhs, 1));
2983 TREE_SIDE_EFFECTS (expr) = 1;
2984 expand_return (expr);
2987 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2988 DECL_RESULT (current_function_decl),
2989 TREE_OPERAND (retval_rhs, 2));
2990 TREE_SIDE_EFFECTS (expr) = 1;
2991 expand_return (expr);
2992 end_cleanup_deferral ();
2996 /* If the result is an aggregate that is being returned in one (or more)
2997 registers, load the registers here. The compiler currently can't handle
2998 copying a BLKmode value into registers. We could put this code in a
2999 more general area (for use by everyone instead of just function
3000 call/return), but until this feature is generally usable it is kept here
3001 (and in expand_call). The value must go into a pseudo in case there
3002 are cleanups that will clobber the real return register. */
3005 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
3006 && GET_CODE (result_rtl) == REG)
3009 unsigned HOST_WIDE_INT bitpos, xbitpos;
3010 unsigned HOST_WIDE_INT big_endian_correction = 0;
3011 unsigned HOST_WIDE_INT bytes
3012 = int_size_in_bytes (TREE_TYPE (retval_rhs));
3013 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
3014 unsigned int bitsize
3015 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
3016 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
3017 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
3018 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
3019 enum machine_mode tmpmode, result_reg_mode;
3021 /* Structures whose size is not a multiple of a word are aligned
3022 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3023 machine, this means we must skip the empty high order bytes when
3024 calculating the bit offset. */
3025 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
3026 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
3029 /* Copy the structure BITSIZE bits at a time. */
3030 for (bitpos = 0, xbitpos = big_endian_correction;
3031 bitpos < bytes * BITS_PER_UNIT;
3032 bitpos += bitsize, xbitpos += bitsize)
3034 /* We need a new destination pseudo each time xbitpos is
3035 on a word boundary and when xbitpos == big_endian_correction
3036 (the first time through). */
3037 if (xbitpos % BITS_PER_WORD == 0
3038 || xbitpos == big_endian_correction)
3040 /* Generate an appropriate register. */
3041 dst = gen_reg_rtx (word_mode);
3042 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3044 /* Clobber the destination before we move anything into it. */
3045 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3048 /* We need a new source operand each time bitpos is on a word
3050 if (bitpos % BITS_PER_WORD == 0)
3051 src = operand_subword_force (result_val,
3052 bitpos / BITS_PER_WORD,
3055 /* Use bitpos for the source extraction (left justified) and
3056 xbitpos for the destination store (right justified). */
3057 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3058 extract_bit_field (src, bitsize,
3059 bitpos % BITS_PER_WORD, 1,
3060 NULL_RTX, word_mode, word_mode,
3061 bitsize, BITS_PER_WORD),
3062 bitsize, BITS_PER_WORD);
3065 /* Find the smallest integer mode large enough to hold the
3066 entire structure and use that mode instead of BLKmode
3067 on the USE insn for the return register. */
3068 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3069 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3070 tmpmode != VOIDmode;
3071 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3073 /* Have we found a large enough mode? */
3074 if (GET_MODE_SIZE (tmpmode) >= bytes)
3078 /* No suitable mode found. */
3079 if (tmpmode == VOIDmode)
3082 PUT_MODE (result_rtl, tmpmode);
3084 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3085 result_reg_mode = word_mode;
3087 result_reg_mode = tmpmode;
3088 result_reg = gen_reg_rtx (result_reg_mode);
3091 for (i = 0; i < n_regs; i++)
3092 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3095 if (tmpmode != result_reg_mode)
3096 result_reg = gen_lowpart (tmpmode, result_reg);
3098 expand_value_return (result_reg);
3102 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3103 && (GET_CODE (result_rtl) == REG
3104 || (GET_CODE (result_rtl) == PARALLEL)))
3106 /* Calculate the return value into a temporary (usually a pseudo
3108 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3110 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3111 val = force_not_mem (val);
3113 /* Return the calculated value, doing cleanups first. */
3114 expand_value_return (val);
3118 /* No cleanups or no hard reg used;
3119 calculate value into hard return reg. */
3120 expand_expr (retval, const0_rtx, VOIDmode, 0);
3122 expand_value_return (result_rtl);
3126 /* Return 1 if the end of the generated RTX is not a barrier.
3127 This means code already compiled can drop through. */
3130 drop_through_at_end_p ()
3132 rtx insn = get_last_insn ();
3133 while (insn && GET_CODE (insn) == NOTE)
3134 insn = PREV_INSN (insn);
3135 return insn && GET_CODE (insn) != BARRIER;
3138 /* Attempt to optimize a potential tail recursion call into a goto.
3139 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3140 where to place the jump to the tail recursion label.
3142 Return TRUE if the call was optimized into a goto. */
3145 optimize_tail_recursion (arguments, last_insn)
3149 /* Finish checking validity, and if valid emit code to set the
3150 argument variables for the new call. */
3151 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3153 if (tail_recursion_label == 0)
3155 tail_recursion_label = gen_label_rtx ();
3156 emit_label_after (tail_recursion_label,
3157 tail_recursion_reentry);
3160 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3167 /* Emit code to alter this function's formal parms for a tail-recursive call.
3168 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3169 FORMALS is the chain of decls of formals.
3170 Return 1 if this can be done;
3171 otherwise return 0 and do not emit any code. */
3174 tail_recursion_args (actuals, formals)
3175 tree actuals, formals;
3177 register tree a = actuals, f = formals;
3179 register rtx *argvec;
3181 /* Check that number and types of actuals are compatible
3182 with the formals. This is not always true in valid C code.
3183 Also check that no formal needs to be addressable
3184 and that all formals are scalars. */
3186 /* Also count the args. */
3188 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3190 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3191 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3193 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3196 if (a != 0 || f != 0)
3199 /* Compute all the actuals. */
3201 argvec = (rtx *) alloca (i * sizeof (rtx));
3203 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3204 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3206 /* Find which actual values refer to current values of previous formals.
3207 Copy each of them now, before any formal is changed. */
3209 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3213 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3214 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3220 argvec[i] = copy_to_reg (argvec[i]);
3223 /* Store the values of the actuals into the formals. */
3225 for (f = formals, a = actuals, i = 0; f;
3226 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3228 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3229 emit_move_insn (DECL_RTL (f), argvec[i]);
3231 convert_move (DECL_RTL (f), argvec[i],
3232 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3239 /* Generate the RTL code for entering a binding contour.
3240 The variables are declared one by one, by calls to `expand_decl'.
3242 FLAGS is a bitwise or of the following flags:
3244 1 - Nonzero if this construct should be visible to
3247 2 - Nonzero if this contour does not require a
3248 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3249 language-independent code should set this flag because they
3250 will not create corresponding BLOCK nodes. (There should be
3251 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3252 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3253 when expand_end_bindings is called.
3255 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3256 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3260 expand_start_bindings_and_block (flags, block)
3264 struct nesting *thisblock = ALLOC_NESTING ();
3266 int exit_flag = ((flags & 1) != 0);
3267 int block_flag = ((flags & 2) == 0);
3269 /* If a BLOCK is supplied, then the caller should be requesting a
3270 NOTE_INSN_BLOCK_BEG note. */
3271 if (!block_flag && block)
3274 /* Create a note to mark the beginning of the block. */
3277 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3278 NOTE_BLOCK (note) = block;
3281 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3283 /* Make an entry on block_stack for the block we are entering. */
3285 thisblock->next = block_stack;
3286 thisblock->all = nesting_stack;
3287 thisblock->depth = ++nesting_depth;
3288 thisblock->data.block.stack_level = 0;
3289 thisblock->data.block.cleanups = 0;
3290 thisblock->data.block.n_function_calls = 0;
3291 thisblock->data.block.exception_region = 0;
3292 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3294 thisblock->data.block.conditional_code = 0;
3295 thisblock->data.block.last_unconditional_cleanup = note;
3296 /* When we insert instructions after the last unconditional cleanup,
3297 we don't adjust last_insn. That means that a later add_insn will
3298 clobber the instructions we've just added. The easiest way to
3299 fix this is to just insert another instruction here, so that the
3300 instructions inserted after the last unconditional cleanup are
3301 never the last instruction. */
3302 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3303 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3306 && !(block_stack->data.block.cleanups == NULL_TREE
3307 && block_stack->data.block.outer_cleanups == NULL_TREE))
3308 thisblock->data.block.outer_cleanups
3309 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3310 block_stack->data.block.outer_cleanups);
3312 thisblock->data.block.outer_cleanups = 0;
3313 thisblock->data.block.label_chain = 0;
3314 thisblock->data.block.innermost_stack_block = stack_block_stack;
3315 thisblock->data.block.first_insn = note;
3316 thisblock->data.block.block_start_count = ++current_block_start_count;
3317 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3318 block_stack = thisblock;
3319 nesting_stack = thisblock;
3321 /* Make a new level for allocating stack slots. */
3325 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3326 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3327 expand_expr are made. After we end the region, we know that all
3328 space for all temporaries that were created by TARGET_EXPRs will be
3329 destroyed and their space freed for reuse. */
3332 expand_start_target_temps ()
3334 /* This is so that even if the result is preserved, the space
3335 allocated will be freed, as we know that it is no longer in use. */
3338 /* Start a new binding layer that will keep track of all cleanup
3339 actions to be performed. */
3340 expand_start_bindings (2);
3342 target_temp_slot_level = temp_slot_level;
3346 expand_end_target_temps ()
3348 expand_end_bindings (NULL_TREE, 0, 0);
3350 /* This is so that even if the result is preserved, the space
3351 allocated will be freed, as we know that it is no longer in use. */
3355 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3356 in question represents the outermost pair of curly braces (i.e. the "body
3357 block") of a function or method.
3359 For any BLOCK node representing a "body block" of a function or method, the
3360 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3361 represents the outermost (function) scope for the function or method (i.e.
3362 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3363 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3366 is_body_block (stmt)
3369 if (TREE_CODE (stmt) == BLOCK)
3371 tree parent = BLOCK_SUPERCONTEXT (stmt);
3373 if (parent && TREE_CODE (parent) == BLOCK)
3375 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3377 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3385 /* Mark top block of block_stack as an implicit binding for an
3386 exception region. This is used to prevent infinite recursion when
3387 ending a binding with expand_end_bindings. It is only ever called
3388 by expand_eh_region_start, as that it the only way to create a
3389 block stack for a exception region. */
3392 mark_block_as_eh_region ()
3394 block_stack->data.block.exception_region = 1;
3395 if (block_stack->next
3396 && block_stack->next->data.block.conditional_code)
3398 block_stack->data.block.conditional_code
3399 = block_stack->next->data.block.conditional_code;
3400 block_stack->data.block.last_unconditional_cleanup
3401 = block_stack->next->data.block.last_unconditional_cleanup;
3402 block_stack->data.block.cleanup_ptr
3403 = block_stack->next->data.block.cleanup_ptr;
3407 /* True if we are currently emitting insns in an area of output code
3408 that is controlled by a conditional expression. This is used by
3409 the cleanup handling code to generate conditional cleanup actions. */
3412 conditional_context ()
3414 return block_stack && block_stack->data.block.conditional_code;
3417 /* Mark top block of block_stack as not for an implicit binding for an
3418 exception region. This is only ever done by expand_eh_region_end
3419 to let expand_end_bindings know that it is being called explicitly
3420 to end the binding layer for just the binding layer associated with
3421 the exception region, otherwise expand_end_bindings would try and
3422 end all implicit binding layers for exceptions regions, and then
3423 one normal binding layer. */
3426 mark_block_as_not_eh_region ()
3428 block_stack->data.block.exception_region = 0;
3431 /* True if the top block of block_stack was marked as for an exception
3432 region by mark_block_as_eh_region. */
3437 return cfun && block_stack && block_stack->data.block.exception_region;
3440 /* Emit a handler label for a nonlocal goto handler.
3441 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3444 expand_nl_handler_label (slot, before_insn)
3445 rtx slot, before_insn;
3448 rtx handler_label = gen_label_rtx ();
3450 /* Don't let jump_optimize delete the handler. */
3451 LABEL_PRESERVE_P (handler_label) = 1;
3454 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3455 insns = get_insns ();
3457 emit_insns_before (insns, before_insn);
3459 emit_label (handler_label);
3461 return handler_label;
3464 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3467 expand_nl_goto_receiver ()
3469 #ifdef HAVE_nonlocal_goto
3470 if (! HAVE_nonlocal_goto)
3472 /* First adjust our frame pointer to its actual value. It was
3473 previously set to the start of the virtual area corresponding to
3474 the stacked variables when we branched here and now needs to be
3475 adjusted to the actual hardware fp value.
3477 Assignments are to virtual registers are converted by
3478 instantiate_virtual_regs into the corresponding assignment
3479 to the underlying register (fp in this case) that makes
3480 the original assignment true.
3481 So the following insn will actually be
3482 decrementing fp by STARTING_FRAME_OFFSET. */
3483 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3485 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3486 if (fixed_regs[ARG_POINTER_REGNUM])
3488 #ifdef ELIMINABLE_REGS
3489 /* If the argument pointer can be eliminated in favor of the
3490 frame pointer, we don't need to restore it. We assume here
3491 that if such an elimination is present, it can always be used.
3492 This is the case on all known machines; if we don't make this
3493 assumption, we do unnecessary saving on many machines. */
3494 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3497 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3498 if (elim_regs[i].from == ARG_POINTER_REGNUM
3499 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3502 if (i == ARRAY_SIZE (elim_regs))
3505 /* Now restore our arg pointer from the address at which it
3506 was saved in our stack frame.
3507 If there hasn't be space allocated for it yet, make
3509 if (arg_pointer_save_area == 0)
3510 arg_pointer_save_area
3511 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3512 emit_move_insn (virtual_incoming_args_rtx,
3513 /* We need a pseudo here, or else
3514 instantiate_virtual_regs_1 complains. */
3515 copy_to_reg (arg_pointer_save_area));
3520 #ifdef HAVE_nonlocal_goto_receiver
3521 if (HAVE_nonlocal_goto_receiver)
3522 emit_insn (gen_nonlocal_goto_receiver ());
3526 /* Make handlers for nonlocal gotos taking place in the function calls in
3530 expand_nl_goto_receivers (thisblock)
3531 struct nesting *thisblock;
3534 rtx afterward = gen_label_rtx ();
3539 /* Record the handler address in the stack slot for that purpose,
3540 during this block, saving and restoring the outer value. */
3541 if (thisblock->next != 0)
3542 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3544 rtx save_receiver = gen_reg_rtx (Pmode);
3545 emit_move_insn (XEXP (slot, 0), save_receiver);
3548 emit_move_insn (save_receiver, XEXP (slot, 0));
3549 insns = get_insns ();
3551 emit_insns_before (insns, thisblock->data.block.first_insn);
3554 /* Jump around the handlers; they run only when specially invoked. */
3555 emit_jump (afterward);
3557 /* Make a separate handler for each label. */
3558 link = nonlocal_labels;
3559 slot = nonlocal_goto_handler_slots;
3560 label_list = NULL_RTX;
3561 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3562 /* Skip any labels we shouldn't be able to jump to from here,
3563 we generate one special handler for all of them below which just calls
3565 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3568 lab = expand_nl_handler_label (XEXP (slot, 0),
3569 thisblock->data.block.first_insn);
3570 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3572 expand_nl_goto_receiver ();
3574 /* Jump to the "real" nonlocal label. */
3575 expand_goto (TREE_VALUE (link));
3578 /* A second pass over all nonlocal labels; this time we handle those
3579 we should not be able to jump to at this point. */
3580 link = nonlocal_labels;
3581 slot = nonlocal_goto_handler_slots;
3583 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3584 if (DECL_TOO_LATE (TREE_VALUE (link)))
3587 lab = expand_nl_handler_label (XEXP (slot, 0),
3588 thisblock->data.block.first_insn);
3589 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3595 expand_nl_goto_receiver ();
3596 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3601 nonlocal_goto_handler_labels = label_list;
3602 emit_label (afterward);
3605 /* Warn about any unused VARS (which may contain nodes other than
3606 VAR_DECLs, but such nodes are ignored). The nodes are connected
3607 via the TREE_CHAIN field. */
3610 warn_about_unused_variables (vars)
3615 if (warn_unused_variable)
3616 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3617 if (TREE_CODE (decl) == VAR_DECL
3618 && ! TREE_USED (decl)
3619 && ! DECL_IN_SYSTEM_HEADER (decl)
3620 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3621 warning_with_decl (decl, "unused variable `%s'");
3624 /* Generate RTL code to terminate a binding contour.
3626 VARS is the chain of VAR_DECL nodes for the variables bound in this
3627 contour. There may actually be other nodes in this chain, but any
3628 nodes other than VAR_DECLS are ignored.
3630 MARK_ENDS is nonzero if we should put a note at the beginning
3631 and end of this binding contour.
3633 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3634 (That is true automatically if the contour has a saved stack level.) */
3637 expand_end_bindings (vars, mark_ends, dont_jump_in)
3642 register struct nesting *thisblock;
3644 while (block_stack->data.block.exception_region)
3646 /* Because we don't need or want a new temporary level and
3647 because we didn't create one in expand_eh_region_start,
3648 create a fake one now to avoid removing one in
3649 expand_end_bindings. */
3652 block_stack->data.block.exception_region = 0;
3654 expand_end_bindings (NULL_TREE, 0, 0);
3657 /* Since expand_eh_region_start does an expand_start_bindings, we
3658 have to first end all the bindings that were created by
3659 expand_eh_region_start. */
3661 thisblock = block_stack;
3663 /* If any of the variables in this scope were not used, warn the
3665 warn_about_unused_variables (vars);
3667 if (thisblock->exit_label)
3669 do_pending_stack_adjust ();
3670 emit_label (thisblock->exit_label);
3673 /* If necessary, make handlers for nonlocal gotos taking
3674 place in the function calls in this block. */
3675 if (function_call_count != thisblock->data.block.n_function_calls
3677 /* Make handler for outermost block
3678 if there were any nonlocal gotos to this function. */
3679 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3680 /* Make handler for inner block if it has something
3681 special to do when you jump out of it. */
3682 : (thisblock->data.block.cleanups != 0
3683 || thisblock->data.block.stack_level != 0)))
3684 expand_nl_goto_receivers (thisblock);
3686 /* Don't allow jumping into a block that has a stack level.
3687 Cleanups are allowed, though. */
3689 || thisblock->data.block.stack_level != 0)
3691 struct label_chain *chain;
3693 /* Any labels in this block are no longer valid to go to.
3694 Mark them to cause an error message. */
3695 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3697 DECL_TOO_LATE (chain->label) = 1;
3698 /* If any goto without a fixup came to this label,
3699 that must be an error, because gotos without fixups
3700 come from outside all saved stack-levels. */
3701 if (TREE_ADDRESSABLE (chain->label))
3702 error_with_decl (chain->label,
3703 "label `%s' used before containing binding contour");
3707 /* Restore stack level in effect before the block
3708 (only if variable-size objects allocated). */
3709 /* Perform any cleanups associated with the block. */
3711 if (thisblock->data.block.stack_level != 0
3712 || thisblock->data.block.cleanups != 0)
3717 /* Don't let cleanups affect ({...}) constructs. */
3718 int old_expr_stmts_for_value = expr_stmts_for_value;
3719 rtx old_last_expr_value = last_expr_value;
3720 tree old_last_expr_type = last_expr_type;
3721 expr_stmts_for_value = 0;
3723 /* Only clean up here if this point can actually be reached. */
3724 insn = get_last_insn ();
3725 if (GET_CODE (insn) == NOTE)
3726 insn = prev_nonnote_insn (insn);
3727 reachable = (! insn || GET_CODE (insn) != BARRIER);
3729 /* Do the cleanups. */
3730 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3732 do_pending_stack_adjust ();
3734 expr_stmts_for_value = old_expr_stmts_for_value;
3735 last_expr_value = old_last_expr_value;
3736 last_expr_type = old_last_expr_type;
3738 /* Restore the stack level. */
3740 if (reachable && thisblock->data.block.stack_level != 0)
3742 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3743 thisblock->data.block.stack_level, NULL_RTX);
3744 if (nonlocal_goto_handler_slots != 0)
3745 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3749 /* Any gotos out of this block must also do these things.
3750 Also report any gotos with fixups that came to labels in this
3752 fixup_gotos (thisblock,
3753 thisblock->data.block.stack_level,
3754 thisblock->data.block.cleanups,
3755 thisblock->data.block.first_insn,
3759 /* Mark the beginning and end of the scope if requested.
3760 We do this now, after running cleanups on the variables
3761 just going out of scope, so they are in scope for their cleanups. */
3765 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3766 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3769 /* Get rid of the beginning-mark if we don't make an end-mark. */
3770 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3772 /* Restore the temporary level of TARGET_EXPRs. */
3773 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3775 /* Restore block_stack level for containing block. */
3777 stack_block_stack = thisblock->data.block.innermost_stack_block;
3778 POPSTACK (block_stack);
3780 /* Pop the stack slot nesting and free any slots at this level. */
3784 /* Generate code to save the stack pointer at the start of the current block
3785 and set up to restore it on exit. */
3788 save_stack_pointer ()
3790 struct nesting *thisblock = block_stack;
3792 if (thisblock->data.block.stack_level == 0)
3794 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3795 &thisblock->data.block.stack_level,
3796 thisblock->data.block.first_insn);
3797 stack_block_stack = thisblock;
3801 /* Generate RTL for the automatic variable declaration DECL.
3802 (Other kinds of declarations are simply ignored if seen here.) */
3808 struct nesting *thisblock;
3811 type = TREE_TYPE (decl);
3813 /* Only automatic variables need any expansion done.
3814 Static and external variables, and external functions,
3815 will be handled by `assemble_variable' (called from finish_decl).
3816 TYPE_DECL and CONST_DECL require nothing.
3817 PARM_DECLs are handled in `assign_parms'. */
3819 if (TREE_CODE (decl) != VAR_DECL)
3821 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3824 thisblock = block_stack;
3826 /* Create the RTL representation for the variable. */
3828 if (type == error_mark_node)
3829 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3830 else if (DECL_SIZE (decl) == 0)
3831 /* Variable with incomplete type. */
3833 if (DECL_INITIAL (decl) == 0)
3834 /* Error message was already done; now avoid a crash. */
3835 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3837 /* An initializer is going to decide the size of this array.
3838 Until we know the size, represent its address with a reg. */
3839 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3841 set_mem_attributes (DECL_RTL (decl), decl, 1);
3843 else if (DECL_MODE (decl) != BLKmode
3844 /* If -ffloat-store, don't put explicit float vars
3846 && !(flag_float_store
3847 && TREE_CODE (type) == REAL_TYPE)
3848 && ! TREE_THIS_VOLATILE (decl)
3849 && (DECL_REGISTER (decl) || optimize)
3850 /* if -fcheck-memory-usage, check all variables. */
3851 && ! current_function_check_memory_usage)
3853 /* Automatic variable that can go in a register. */
3854 int unsignedp = TREE_UNSIGNED (type);
3855 enum machine_mode reg_mode
3856 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3858 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3859 mark_user_reg (DECL_RTL (decl));
3861 if (POINTER_TYPE_P (type))
3862 mark_reg_pointer (DECL_RTL (decl),
3863 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3865 maybe_set_unchanging (DECL_RTL (decl), decl);
3867 /* If something wants our address, try to use ADDRESSOF. */
3868 if (TREE_ADDRESSABLE (decl))
3869 put_var_into_stack (decl);
3872 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3873 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3874 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3875 STACK_CHECK_MAX_VAR_SIZE)))
3877 /* Variable of fixed size that goes on the stack. */
3881 /* If we previously made RTL for this decl, it must be an array
3882 whose size was determined by the initializer.
3883 The old address was a register; set that register now
3884 to the proper address. */
3885 if (DECL_RTL (decl) != 0)
3887 if (GET_CODE (DECL_RTL (decl)) != MEM
3888 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3890 oldaddr = XEXP (DECL_RTL (decl), 0);
3893 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3895 /* Set alignment we actually gave this decl. */
3896 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3897 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3898 DECL_USER_ALIGN (decl) = 0;
3902 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3903 if (addr != oldaddr)
3904 emit_move_insn (oldaddr, addr);
3908 /* Dynamic-size object: must push space on the stack. */
3912 /* Record the stack pointer on entry to block, if have
3913 not already done so. */
3914 do_pending_stack_adjust ();
3915 save_stack_pointer ();
3917 /* In function-at-a-time mode, variable_size doesn't expand this,
3919 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3920 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3921 const0_rtx, VOIDmode, 0);
3923 /* Compute the variable's size, in bytes. */
3924 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3927 /* Allocate space on the stack for the variable. Note that
3928 DECL_ALIGN says how the variable is to be aligned and we
3929 cannot use it to conclude anything about the alignment of
3931 address = allocate_dynamic_stack_space (size, NULL_RTX,
3932 TYPE_ALIGN (TREE_TYPE (decl)));
3934 /* Reference the variable indirect through that rtx. */
3935 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3937 set_mem_attributes (DECL_RTL (decl), decl, 1);
3939 /* Indicate the alignment we actually gave this variable. */
3940 #ifdef STACK_BOUNDARY
3941 DECL_ALIGN (decl) = STACK_BOUNDARY;
3943 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3945 DECL_USER_ALIGN (decl) = 0;
3949 /* Emit code to perform the initialization of a declaration DECL. */
3952 expand_decl_init (decl)
3955 int was_used = TREE_USED (decl);
3957 /* If this is a CONST_DECL, we don't have to generate any code, but
3958 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3959 to be set while in the obstack containing the constant. If we don't
3960 do this, we can lose if we have functions nested three deep and the middle
3961 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3962 the innermost function is the first to expand that STRING_CST. */
3963 if (TREE_CODE (decl) == CONST_DECL)
3965 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3966 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3967 EXPAND_INITIALIZER);
3971 if (TREE_STATIC (decl))
3974 /* Compute and store the initial value now. */
3976 if (DECL_INITIAL (decl) == error_mark_node)
3978 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3980 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3981 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3982 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3986 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3988 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3989 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3993 /* Don't let the initialization count as "using" the variable. */
3994 TREE_USED (decl) = was_used;
3996 /* Free any temporaries we made while initializing the decl. */
3997 preserve_temp_slots (NULL_RTX);
4001 /* CLEANUP is an expression to be executed at exit from this binding contour;
4002 for example, in C++, it might call the destructor for this variable.
4004 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4005 CLEANUP multiple times, and have the correct semantics. This
4006 happens in exception handling, for gotos, returns, breaks that
4007 leave the current scope.
4009 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4010 that is not associated with any particular variable. */
4013 expand_decl_cleanup (decl, cleanup)
4016 struct nesting *thisblock;
4018 /* Error if we are not in any block. */
4019 if (cfun == 0 || block_stack == 0)
4022 thisblock = block_stack;
4024 /* Record the cleanup if there is one. */
4030 tree *cleanups = &thisblock->data.block.cleanups;
4031 int cond_context = conditional_context ();
4035 rtx flag = gen_reg_rtx (word_mode);
4040 emit_move_insn (flag, const0_rtx);
4041 set_flag_0 = get_insns ();
4044 thisblock->data.block.last_unconditional_cleanup
4045 = emit_insns_after (set_flag_0,
4046 thisblock->data.block.last_unconditional_cleanup);
4048 emit_move_insn (flag, const1_rtx);
4050 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4051 DECL_RTL (cond) = flag;
4053 /* Conditionalize the cleanup. */
4054 cleanup = build (COND_EXPR, void_type_node,
4055 truthvalue_conversion (cond),
4056 cleanup, integer_zero_node);
4057 cleanup = fold (cleanup);
4059 cleanups = thisblock->data.block.cleanup_ptr;
4062 cleanup = unsave_expr (cleanup);
4064 t = *cleanups = tree_cons (decl, cleanup, *cleanups);
4067 /* If this block has a cleanup, it belongs in stack_block_stack. */
4068 stack_block_stack = thisblock;
4075 /* If this was optimized so that there is no exception region for the
4076 cleanup, then mark the TREE_LIST node, so that we can later tell
4077 if we need to call expand_eh_region_end. */
4078 if (! using_eh_for_cleanups_p
4079 || expand_eh_region_start_tree (decl, cleanup))
4080 TREE_ADDRESSABLE (t) = 1;
4081 /* If that started a new EH region, we're in a new block. */
4082 thisblock = block_stack;
4089 thisblock->data.block.last_unconditional_cleanup
4090 = emit_insns_after (seq,
4091 thisblock->data.block.last_unconditional_cleanup);
4095 thisblock->data.block.last_unconditional_cleanup
4097 /* When we insert instructions after the last unconditional cleanup,
4098 we don't adjust last_insn. That means that a later add_insn will
4099 clobber the instructions we've just added. The easiest way to
4100 fix this is to just insert another instruction here, so that the
4101 instructions inserted after the last unconditional cleanup are
4102 never the last instruction. */
4103 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4104 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4110 /* Like expand_decl_cleanup, but suppress generating an exception handler
4111 to perform the cleanup. */
4115 expand_decl_cleanup_no_eh (decl, cleanup)
4118 int save_eh = using_eh_for_cleanups_p;
4121 using_eh_for_cleanups_p = 0;
4122 result = expand_decl_cleanup (decl, cleanup);
4123 using_eh_for_cleanups_p = save_eh;
4129 /* Arrange for the top element of the dynamic cleanup chain to be
4130 popped if we exit the current binding contour. DECL is the
4131 associated declaration, if any, otherwise NULL_TREE. If the
4132 current contour is left via an exception, then __sjthrow will pop
4133 the top element off the dynamic cleanup chain. The code that
4134 avoids doing the action we push into the cleanup chain in the
4135 exceptional case is contained in expand_cleanups.
4137 This routine is only used by expand_eh_region_start, and that is
4138 the only way in which an exception region should be started. This
4139 routine is only used when using the setjmp/longjmp codegen method
4140 for exception handling. */
4143 expand_dcc_cleanup (decl)
4146 struct nesting *thisblock;
4149 /* Error if we are not in any block. */
4150 if (cfun == 0 || block_stack == 0)
4152 thisblock = block_stack;
4154 /* Record the cleanup for the dynamic handler chain. */
4156 cleanup = make_node (POPDCC_EXPR);
4158 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4159 thisblock->data.block.cleanups
4160 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4162 /* If this block has a cleanup, it belongs in stack_block_stack. */
4163 stack_block_stack = thisblock;
4167 /* Arrange for the top element of the dynamic handler chain to be
4168 popped if we exit the current binding contour. DECL is the
4169 associated declaration, if any, otherwise NULL_TREE. If the current
4170 contour is left via an exception, then __sjthrow will pop the top
4171 element off the dynamic handler chain. The code that avoids doing
4172 the action we push into the handler chain in the exceptional case
4173 is contained in expand_cleanups.
4175 This routine is only used by expand_eh_region_start, and that is
4176 the only way in which an exception region should be started. This
4177 routine is only used when using the setjmp/longjmp codegen method
4178 for exception handling. */
4181 expand_dhc_cleanup (decl)
4184 struct nesting *thisblock;
4187 /* Error if we are not in any block. */
4188 if (cfun == 0 || block_stack == 0)
4190 thisblock = block_stack;
4192 /* Record the cleanup for the dynamic handler chain. */
4194 cleanup = make_node (POPDHC_EXPR);
4196 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4197 thisblock->data.block.cleanups
4198 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4200 /* If this block has a cleanup, it belongs in stack_block_stack. */
4201 stack_block_stack = thisblock;
4205 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4206 DECL_ELTS is the list of elements that belong to DECL's type.
4207 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4210 expand_anon_union_decl (decl, cleanup, decl_elts)
4211 tree decl, cleanup, decl_elts;
4213 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4217 /* If any of the elements are addressable, so is the entire union. */
4218 for (t = decl_elts; t; t = TREE_CHAIN (t))
4219 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4221 TREE_ADDRESSABLE (decl) = 1;
4226 expand_decl_cleanup (decl, cleanup);
4227 x = DECL_RTL (decl);
4229 /* Go through the elements, assigning RTL to each. */
4230 for (t = decl_elts; t; t = TREE_CHAIN (t))
4232 tree decl_elt = TREE_VALUE (t);
4233 tree cleanup_elt = TREE_PURPOSE (t);
4234 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4236 /* Propagate the union's alignment to the elements. */
4237 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4238 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4240 /* If the element has BLKmode and the union doesn't, the union is
4241 aligned such that the element doesn't need to have BLKmode, so
4242 change the element's mode to the appropriate one for its size. */
4243 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4244 DECL_MODE (decl_elt) = mode
4245 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4247 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4248 instead create a new MEM rtx with the proper mode. */
4249 if (GET_CODE (x) == MEM)
4251 if (mode == GET_MODE (x))
4252 DECL_RTL (decl_elt) = x;
4255 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4256 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4259 else if (GET_CODE (x) == REG)
4261 if (mode == GET_MODE (x))
4262 DECL_RTL (decl_elt) = x;
4264 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4269 /* Record the cleanup if there is one. */
4272 thisblock->data.block.cleanups
4273 = tree_cons (decl_elt, cleanup_elt,
4274 thisblock->data.block.cleanups);
4278 /* Expand a list of cleanups LIST.
4279 Elements may be expressions or may be nested lists.
4281 If DONT_DO is nonnull, then any list-element
4282 whose TREE_PURPOSE matches DONT_DO is omitted.
4283 This is sometimes used to avoid a cleanup associated with
4284 a value that is being returned out of the scope.
4286 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4287 goto and handle protection regions specially in that case.
4289 If REACHABLE, we emit code, otherwise just inform the exception handling
4290 code about this finalization. */
4293 expand_cleanups (list, dont_do, in_fixup, reachable)
4300 for (tail = list; tail; tail = TREE_CHAIN (tail))
4301 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4303 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4304 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4309 tree cleanup = TREE_VALUE (tail);
4311 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4312 if (TREE_CODE (cleanup) != POPDHC_EXPR
4313 && TREE_CODE (cleanup) != POPDCC_EXPR
4314 /* See expand_eh_region_start_tree for this case. */
4315 && ! TREE_ADDRESSABLE (tail))
4317 cleanup = protect_with_terminate (cleanup);
4318 expand_eh_region_end (cleanup);
4324 /* Cleanups may be run multiple times. For example,
4325 when exiting a binding contour, we expand the
4326 cleanups associated with that contour. When a goto
4327 within that binding contour has a target outside that
4328 contour, it will expand all cleanups from its scope to
4329 the target. Though the cleanups are expanded multiple
4330 times, the control paths are non-overlapping so the
4331 cleanups will not be executed twice. */
4333 /* We may need to protect fixups with rethrow regions. */
4334 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4337 expand_fixup_region_start ();
4339 /* The cleanup might contain try-blocks, so we have to
4340 preserve our current queue. */
4342 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4345 expand_fixup_region_end (TREE_VALUE (tail));
4352 /* Mark when the context we are emitting RTL for as a conditional
4353 context, so that any cleanup actions we register with
4354 expand_decl_init will be properly conditionalized when those
4355 cleanup actions are later performed. Must be called before any
4356 expression (tree) is expanded that is within a conditional context. */
4359 start_cleanup_deferral ()
4361 /* block_stack can be NULL if we are inside the parameter list. It is
4362 OK to do nothing, because cleanups aren't possible here. */
4364 ++block_stack->data.block.conditional_code;
4367 /* Mark the end of a conditional region of code. Because cleanup
4368 deferrals may be nested, we may still be in a conditional region
4369 after we end the currently deferred cleanups, only after we end all
4370 deferred cleanups, are we back in unconditional code. */
4373 end_cleanup_deferral ()
4375 /* block_stack can be NULL if we are inside the parameter list. It is
4376 OK to do nothing, because cleanups aren't possible here. */
4378 --block_stack->data.block.conditional_code;
4381 /* Move all cleanups from the current block_stack
4382 to the containing block_stack, where they are assumed to
4383 have been created. If anything can cause a temporary to
4384 be created, but not expanded for more than one level of
4385 block_stacks, then this code will have to change. */
4390 struct nesting *block = block_stack;
4391 struct nesting *outer = block->next;
4393 outer->data.block.cleanups
4394 = chainon (block->data.block.cleanups,
4395 outer->data.block.cleanups);
4396 block->data.block.cleanups = 0;
4400 last_cleanup_this_contour ()
4402 if (block_stack == 0)
4405 return block_stack->data.block.cleanups;
4408 /* Return 1 if there are any pending cleanups at this point.
4409 If THIS_CONTOUR is nonzero, check the current contour as well.
4410 Otherwise, look only at the contours that enclose this one. */
4413 any_pending_cleanups (this_contour)
4416 struct nesting *block;
4418 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4421 if (this_contour && block_stack->data.block.cleanups != NULL)
4423 if (block_stack->data.block.cleanups == 0
4424 && block_stack->data.block.outer_cleanups == 0)
4427 for (block = block_stack->next; block; block = block->next)
4428 if (block->data.block.cleanups != 0)
4434 /* Enter a case (Pascal) or switch (C) statement.
4435 Push a block onto case_stack and nesting_stack
4436 to accumulate the case-labels that are seen
4437 and to record the labels generated for the statement.
4439 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4440 Otherwise, this construct is transparent for `exit_something'.
4442 EXPR is the index-expression to be dispatched on.
4443 TYPE is its nominal type. We could simply convert EXPR to this type,
4444 but instead we take short cuts. */
4447 expand_start_case (exit_flag, expr, type, printname)
4451 const char *printname;
4453 register struct nesting *thiscase = ALLOC_NESTING ();
4455 /* Make an entry on case_stack for the case we are entering. */
4457 thiscase->next = case_stack;
4458 thiscase->all = nesting_stack;
4459 thiscase->depth = ++nesting_depth;
4460 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4461 thiscase->data.case_stmt.case_list = 0;
4462 thiscase->data.case_stmt.index_expr = expr;
4463 thiscase->data.case_stmt.nominal_type = type;
4464 thiscase->data.case_stmt.default_label = 0;
4465 thiscase->data.case_stmt.printname = printname;
4466 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4467 case_stack = thiscase;
4468 nesting_stack = thiscase;
4470 do_pending_stack_adjust ();
4472 /* Make sure case_stmt.start points to something that won't
4473 need any transformation before expand_end_case. */
4474 if (GET_CODE (get_last_insn ()) != NOTE)
4475 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4477 thiscase->data.case_stmt.start = get_last_insn ();
4479 start_cleanup_deferral ();
4482 /* Start a "dummy case statement" within which case labels are invalid
4483 and are not connected to any larger real case statement.
4484 This can be used if you don't want to let a case statement jump
4485 into the middle of certain kinds of constructs. */
4488 expand_start_case_dummy ()
4490 register struct nesting *thiscase = ALLOC_NESTING ();
4492 /* Make an entry on case_stack for the dummy. */
4494 thiscase->next = case_stack;
4495 thiscase->all = nesting_stack;
4496 thiscase->depth = ++nesting_depth;
4497 thiscase->exit_label = 0;
4498 thiscase->data.case_stmt.case_list = 0;
4499 thiscase->data.case_stmt.start = 0;
4500 thiscase->data.case_stmt.nominal_type = 0;
4501 thiscase->data.case_stmt.default_label = 0;
4502 case_stack = thiscase;
4503 nesting_stack = thiscase;
4504 start_cleanup_deferral ();
4507 /* End a dummy case statement. */
4510 expand_end_case_dummy ()
4512 end_cleanup_deferral ();
4513 POPSTACK (case_stack);
4516 /* Return the data type of the index-expression
4517 of the innermost case statement, or null if none. */
4520 case_index_expr_type ()
4523 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4530 /* If this is the first label, warn if any insns have been emitted. */
4531 if (case_stack->data.case_stmt.line_number_status >= 0)
4535 restore_line_number_status
4536 (case_stack->data.case_stmt.line_number_status);
4537 case_stack->data.case_stmt.line_number_status = -1;
4539 for (insn = case_stack->data.case_stmt.start;
4541 insn = NEXT_INSN (insn))
4543 if (GET_CODE (insn) == CODE_LABEL)
4545 if (GET_CODE (insn) != NOTE
4546 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4549 insn = PREV_INSN (insn);
4550 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4552 /* If insn is zero, then there must have been a syntax error. */
4554 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4555 NOTE_LINE_NUMBER (insn),
4556 "unreachable code at beginning of %s",
4557 case_stack->data.case_stmt.printname);
4564 /* Accumulate one case or default label inside a case or switch statement.
4565 VALUE is the value of the case (a null pointer, for a default label).
4566 The function CONVERTER, when applied to arguments T and V,
4567 converts the value V to the type T.
4569 If not currently inside a case or switch statement, return 1 and do
4570 nothing. The caller will print a language-specific error message.
4571 If VALUE is a duplicate or overlaps, return 2 and do nothing
4572 except store the (first) duplicate node in *DUPLICATE.
4573 If VALUE is out of range, return 3 and do nothing.
4574 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4575 Return 0 on success.
4577 Extended to handle range statements. */
4580 pushcase (value, converter, label, duplicate)
4581 register tree value;
4582 tree (*converter) PARAMS ((tree, tree));
4583 register tree label;
4589 /* Fail if not inside a real case statement. */
4590 if (! (case_stack && case_stack->data.case_stmt.start))
4593 if (stack_block_stack
4594 && stack_block_stack->depth > case_stack->depth)
4597 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4598 nominal_type = case_stack->data.case_stmt.nominal_type;
4600 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4601 if (index_type == error_mark_node)
4604 /* Convert VALUE to the type in which the comparisons are nominally done. */
4606 value = (*converter) (nominal_type, value);
4610 /* Fail if this value is out of range for the actual type of the index
4611 (which may be narrower than NOMINAL_TYPE). */
4613 && (TREE_CONSTANT_OVERFLOW (value)
4614 || ! int_fits_type_p (value, index_type)))
4617 return add_case_node (value, value, label, duplicate);
4620 /* Like pushcase but this case applies to all values between VALUE1 and
4621 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4622 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4623 starts at VALUE1 and ends at the highest value of the index type.
4624 If both are NULL, this case applies to all values.
4626 The return value is the same as that of pushcase but there is one
4627 additional error code: 4 means the specified range was empty. */
4630 pushcase_range (value1, value2, converter, label, duplicate)
4631 register tree value1, value2;
4632 tree (*converter) PARAMS ((tree, tree));
4633 register tree label;
4639 /* Fail if not inside a real case statement. */
4640 if (! (case_stack && case_stack->data.case_stmt.start))
4643 if (stack_block_stack
4644 && stack_block_stack->depth > case_stack->depth)
4647 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4648 nominal_type = case_stack->data.case_stmt.nominal_type;
4650 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4651 if (index_type == error_mark_node)
4656 /* Convert VALUEs to type in which the comparisons are nominally done
4657 and replace any unspecified value with the corresponding bound. */
4659 value1 = TYPE_MIN_VALUE (index_type);
4661 value2 = TYPE_MAX_VALUE (index_type);
4663 /* Fail if the range is empty. Do this before any conversion since
4664 we want to allow out-of-range empty ranges. */
4665 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4668 /* If the max was unbounded, use the max of the nominal_type we are
4669 converting to. Do this after the < check above to suppress false
4672 value2 = TYPE_MAX_VALUE (nominal_type);
4674 value1 = (*converter) (nominal_type, value1);
4675 value2 = (*converter) (nominal_type, value2);
4677 /* Fail if these values are out of range. */
4678 if (TREE_CONSTANT_OVERFLOW (value1)
4679 || ! int_fits_type_p (value1, index_type))
4682 if (TREE_CONSTANT_OVERFLOW (value2)
4683 || ! int_fits_type_p (value2, index_type))
4686 return add_case_node (value1, value2, label, duplicate);
4689 /* Do the actual insertion of a case label for pushcase and pushcase_range
4690 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4691 slowdown for large switch statements. */
4694 add_case_node (low, high, label, duplicate)
4699 struct case_node *p, **q, *r;
4701 /* If there's no HIGH value, then this is not a case range; it's
4702 just a simple case label. But that's just a degenerate case
4707 /* Handle default labels specially. */
4710 if (case_stack->data.case_stmt.default_label != 0)
4712 *duplicate = case_stack->data.case_stmt.default_label;
4715 case_stack->data.case_stmt.default_label = label;
4716 expand_label (label);
4720 q = &case_stack->data.case_stmt.case_list;
4727 /* Keep going past elements distinctly greater than HIGH. */
4728 if (tree_int_cst_lt (high, p->low))
4731 /* or distinctly less than LOW. */
4732 else if (tree_int_cst_lt (p->high, low))
4737 /* We have an overlap; this is an error. */
4738 *duplicate = p->code_label;
4743 /* Add this label to the chain, and succeed.
4744 Copy LOW, HIGH so they are on temporary rather than momentary
4745 obstack and will thus survive till the end of the case statement. */
4747 r = (struct case_node *) xmalloc (sizeof (struct case_node));
4748 r->low = copy_node (low);
4750 /* If the bounds are equal, turn this into the one-value case. */
4751 if (tree_int_cst_equal (low, high))
4754 r->high = copy_node (high);
4756 r->code_label = label;
4757 expand_label (label);
4767 struct case_node *s;
4773 if (! (b = p->balance))
4774 /* Growth propagation from left side. */
4781 if ((p->left = s = r->right))
4790 if ((r->parent = s))
4798 case_stack->data.case_stmt.case_list = r;
4801 /* r->balance == +1 */
4806 struct case_node *t = r->right;
4808 if ((p->left = s = t->right))
4812 if ((r->right = s = t->left))
4826 if ((t->parent = s))
4834 case_stack->data.case_stmt.case_list = t;
4841 /* p->balance == +1; growth of left side balances the node. */
4851 if (! (b = p->balance))
4852 /* Growth propagation from right side. */
4860 if ((p->right = s = r->left))
4868 if ((r->parent = s))
4877 case_stack->data.case_stmt.case_list = r;
4881 /* r->balance == -1 */
4885 struct case_node *t = r->left;
4887 if ((p->right = s = t->left))
4892 if ((r->left = s = t->right))
4906 if ((t->parent = s))
4915 case_stack->data.case_stmt.case_list = t;
4921 /* p->balance == -1; growth of right side balances the node. */
4934 /* Returns the number of possible values of TYPE.
4935 Returns -1 if the number is unknown, variable, or if the number does not
4936 fit in a HOST_WIDE_INT.
4937 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4938 do not increase monotonically (there may be duplicates);
4939 to 1 if the values increase monotonically, but not always by 1;
4940 otherwise sets it to 0. */
4943 all_cases_count (type, spareness)
4948 HOST_WIDE_INT count, minval, lastval;
4952 switch (TREE_CODE (type))
4959 count = 1 << BITS_PER_UNIT;
4964 if (TYPE_MAX_VALUE (type) != 0
4965 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4966 TYPE_MIN_VALUE (type))))
4967 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4968 convert (type, integer_zero_node))))
4969 && host_integerp (t, 1))
4970 count = tree_low_cst (t, 1);
4976 /* Don't waste time with enumeral types with huge values. */
4977 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4978 || TYPE_MAX_VALUE (type) == 0
4979 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4982 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4985 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4987 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4989 if (*spareness == 2 || thisval < lastval)
4991 else if (thisval != minval + count)
5001 #define BITARRAY_TEST(ARRAY, INDEX) \
5002 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5003 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
5004 #define BITARRAY_SET(ARRAY, INDEX) \
5005 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5006 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
5008 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
5009 with the case values we have seen, assuming the case expression
5011 SPARSENESS is as determined by all_cases_count.
5013 The time needed is proportional to COUNT, unless
5014 SPARSENESS is 2, in which case quadratic time is needed. */
5017 mark_seen_cases (type, cases_seen, count, sparseness)
5019 unsigned char *cases_seen;
5020 HOST_WIDE_INT count;
5023 tree next_node_to_try = NULL_TREE;
5024 HOST_WIDE_INT next_node_offset = 0;
5026 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5027 tree val = make_node (INTEGER_CST);
5029 TREE_TYPE (val) = type;
5033 else if (sparseness == 2)
5036 unsigned HOST_WIDE_INT xlo;
5038 /* This less efficient loop is only needed to handle
5039 duplicate case values (multiple enum constants
5040 with the same value). */
5041 TREE_TYPE (val) = TREE_TYPE (root->low);
5042 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5043 t = TREE_CHAIN (t), xlo++)
5045 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5046 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5050 /* Keep going past elements distinctly greater than VAL. */
5051 if (tree_int_cst_lt (val, n->low))
5054 /* or distinctly less than VAL. */
5055 else if (tree_int_cst_lt (n->high, val))
5060 /* We have found a matching range. */
5061 BITARRAY_SET (cases_seen, xlo);
5071 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5073 for (n = root; n; n = n->right)
5075 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5076 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5077 while (! tree_int_cst_lt (n->high, val))
5079 /* Calculate (into xlo) the "offset" of the integer (val).
5080 The element with lowest value has offset 0, the next smallest
5081 element has offset 1, etc. */
5083 unsigned HOST_WIDE_INT xlo;
5087 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5089 /* The TYPE_VALUES will be in increasing order, so
5090 starting searching where we last ended. */
5091 t = next_node_to_try;
5092 xlo = next_node_offset;
5098 t = TYPE_VALUES (type);
5101 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5103 next_node_to_try = TREE_CHAIN (t);
5104 next_node_offset = xlo + 1;
5109 if (t == next_node_to_try)
5118 t = TYPE_MIN_VALUE (type);
5120 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5124 add_double (xlo, xhi,
5125 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5129 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5130 BITARRAY_SET (cases_seen, xlo);
5132 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5134 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5140 /* Called when the index of a switch statement is an enumerated type
5141 and there is no default label.
5143 Checks that all enumeration literals are covered by the case
5144 expressions of a switch. Also, warn if there are any extra
5145 switch cases that are *not* elements of the enumerated type.
5147 If all enumeration literals were covered by the case expressions,
5148 turn one of the expressions into the default expression since it should
5149 not be possible to fall through such a switch. */
5152 check_for_full_enumeration_handling (type)
5155 register struct case_node *n;
5156 register tree chain;
5157 #if 0 /* variable used by 'if 0'ed code below. */
5158 register struct case_node **l;
5162 /* True iff the selector type is a numbered set mode. */
5165 /* The number of possible selector values. */
5168 /* For each possible selector value. a one iff it has been matched
5169 by a case value alternative. */
5170 unsigned char *cases_seen;
5172 /* The allocated size of cases_seen, in chars. */
5173 HOST_WIDE_INT bytes_needed;
5178 size = all_cases_count (type, &sparseness);
5179 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5181 if (size > 0 && size < 600000
5182 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5183 this optimization if we don't have enough memory rather than
5184 aborting, as xmalloc would do. */
5185 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5188 tree v = TYPE_VALUES (type);
5190 /* The time complexity of this code is normally O(N), where
5191 N being the number of members in the enumerated type.
5192 However, if type is a ENUMERAL_TYPE whose values do not
5193 increase monotonically, O(N*log(N)) time may be needed. */
5195 mark_seen_cases (type, cases_seen, size, sparseness);
5197 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5198 if (BITARRAY_TEST (cases_seen, i) == 0)
5199 warning ("enumeration value `%s' not handled in switch",
5200 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5205 /* Now we go the other way around; we warn if there are case
5206 expressions that don't correspond to enumerators. This can
5207 occur since C and C++ don't enforce type-checking of
5208 assignments to enumeration variables. */
5210 if (case_stack->data.case_stmt.case_list
5211 && case_stack->data.case_stmt.case_list->left)
5212 case_stack->data.case_stmt.case_list
5213 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5215 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5217 for (chain = TYPE_VALUES (type);
5218 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5219 chain = TREE_CHAIN (chain))
5224 if (TYPE_NAME (type) == 0)
5225 warning ("case value `%ld' not in enumerated type",
5226 (long) TREE_INT_CST_LOW (n->low));
5228 warning ("case value `%ld' not in enumerated type `%s'",
5229 (long) TREE_INT_CST_LOW (n->low),
5230 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5233 : DECL_NAME (TYPE_NAME (type))));
5235 if (!tree_int_cst_equal (n->low, n->high))
5237 for (chain = TYPE_VALUES (type);
5238 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5239 chain = TREE_CHAIN (chain))
5244 if (TYPE_NAME (type) == 0)
5245 warning ("case value `%ld' not in enumerated type",
5246 (long) TREE_INT_CST_LOW (n->high));
5248 warning ("case value `%ld' not in enumerated type `%s'",
5249 (long) TREE_INT_CST_LOW (n->high),
5250 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5253 : DECL_NAME (TYPE_NAME (type))));
5259 /* ??? This optimization is disabled because it causes valid programs to
5260 fail. ANSI C does not guarantee that an expression with enum type
5261 will have a value that is the same as one of the enumeration literals. */
5263 /* If all values were found as case labels, make one of them the default
5264 label. Thus, this switch will never fall through. We arbitrarily pick
5265 the last one to make the default since this is likely the most
5266 efficient choice. */
5270 for (l = &case_stack->data.case_stmt.case_list;
5275 case_stack->data.case_stmt.default_label = (*l)->code_label;
5281 /* Free CN, and its children. */
5284 free_case_nodes (cn)
5289 free_case_nodes (cn->left);
5290 free_case_nodes (cn->right);
5296 /* Terminate a case (Pascal) or switch (C) statement
5297 in which ORIG_INDEX is the expression to be tested.
5298 Generate the code to test it and jump to the right place. */
5301 expand_end_case (orig_index)
5304 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5305 rtx default_label = 0;
5306 register struct case_node *n;
5314 register struct nesting *thiscase = case_stack;
5315 tree index_expr, index_type;
5318 /* Don't crash due to previous errors. */
5319 if (thiscase == NULL)
5322 table_label = gen_label_rtx ();
5323 index_expr = thiscase->data.case_stmt.index_expr;
5324 index_type = TREE_TYPE (index_expr);
5325 unsignedp = TREE_UNSIGNED (index_type);
5327 do_pending_stack_adjust ();
5329 /* This might get an spurious warning in the presence of a syntax error;
5330 it could be fixed by moving the call to check_seenlabel after the
5331 check for error_mark_node, and copying the code of check_seenlabel that
5332 deals with case_stack->data.case_stmt.line_number_status /
5333 restore_line_number_status in front of the call to end_cleanup_deferral;
5334 However, this might miss some useful warnings in the presence of
5335 non-syntax errors. */
5338 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5339 if (index_type != error_mark_node)
5341 /* If switch expression was an enumerated type, check that all
5342 enumeration literals are covered by the cases.
5343 No sense trying this if there's a default case, however. */
5345 if (!thiscase->data.case_stmt.default_label
5346 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5347 && TREE_CODE (index_expr) != INTEGER_CST)
5348 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5350 /* If we don't have a default-label, create one here,
5351 after the body of the switch. */
5352 if (thiscase->data.case_stmt.default_label == 0)
5354 thiscase->data.case_stmt.default_label
5355 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5356 expand_label (thiscase->data.case_stmt.default_label);
5358 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5360 before_case = get_last_insn ();
5362 if (thiscase->data.case_stmt.case_list
5363 && thiscase->data.case_stmt.case_list->left)
5364 thiscase->data.case_stmt.case_list
5365 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5367 /* Simplify the case-list before we count it. */
5368 group_case_nodes (thiscase->data.case_stmt.case_list);
5370 /* Get upper and lower bounds of case values.
5371 Also convert all the case values to the index expr's data type. */
5374 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5376 /* Check low and high label values are integers. */
5377 if (TREE_CODE (n->low) != INTEGER_CST)
5379 if (TREE_CODE (n->high) != INTEGER_CST)
5382 n->low = convert (index_type, n->low);
5383 n->high = convert (index_type, n->high);
5385 /* Count the elements and track the largest and smallest
5386 of them (treating them as signed even if they are not). */
5394 if (INT_CST_LT (n->low, minval))
5396 if (INT_CST_LT (maxval, n->high))
5399 /* A range counts double, since it requires two compares. */
5400 if (! tree_int_cst_equal (n->low, n->high))
5404 orig_minval = minval;
5406 /* Compute span of values. */
5408 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5410 end_cleanup_deferral ();
5414 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5416 emit_jump (default_label);
5419 /* If range of values is much bigger than number of values,
5420 make a sequence of conditional branches instead of a dispatch.
5421 If the switch-index is a constant, do it this way
5422 because we can optimize it. */
5424 #ifndef CASE_VALUES_THRESHOLD
5426 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5428 /* If machine does not have a case insn that compares the
5429 bounds, this means extra overhead for dispatch tables
5430 which raises the threshold for using them. */
5431 #define CASE_VALUES_THRESHOLD 5
5432 #endif /* HAVE_casesi */
5433 #endif /* CASE_VALUES_THRESHOLD */
5435 else if (count < CASE_VALUES_THRESHOLD
5436 || compare_tree_int (range, 10 * count) > 0
5437 /* RANGE may be signed, and really large ranges will show up
5438 as negative numbers. */
5439 || compare_tree_int (range, 0) < 0
5440 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5443 || TREE_CODE (index_expr) == INTEGER_CST
5444 /* These will reduce to a constant. */
5445 || (TREE_CODE (index_expr) == CALL_EXPR
5446 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5447 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5448 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5449 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5450 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5451 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5453 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5455 /* If the index is a short or char that we do not have
5456 an insn to handle comparisons directly, convert it to
5457 a full integer now, rather than letting each comparison
5458 generate the conversion. */
5460 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5461 && (cmp_optab->handlers[(int) GET_MODE (index)].insn_code
5462 == CODE_FOR_nothing))
5464 enum machine_mode wider_mode;
5465 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5466 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5467 if (cmp_optab->handlers[(int) wider_mode].insn_code
5468 != CODE_FOR_nothing)
5470 index = convert_to_mode (wider_mode, index, unsignedp);
5476 do_pending_stack_adjust ();
5478 index = protect_from_queue (index, 0);
5479 if (GET_CODE (index) == MEM)
5480 index = copy_to_reg (index);
5481 if (GET_CODE (index) == CONST_INT
5482 || TREE_CODE (index_expr) == INTEGER_CST)
5484 /* Make a tree node with the proper constant value
5485 if we don't already have one. */
5486 if (TREE_CODE (index_expr) != INTEGER_CST)
5489 = build_int_2 (INTVAL (index),
5490 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5491 index_expr = convert (index_type, index_expr);
5494 /* For constant index expressions we need only
5495 issue a unconditional branch to the appropriate
5496 target code. The job of removing any unreachable
5497 code is left to the optimisation phase if the
5498 "-O" option is specified. */
5499 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5500 if (! tree_int_cst_lt (index_expr, n->low)
5501 && ! tree_int_cst_lt (n->high, index_expr))
5505 emit_jump (label_rtx (n->code_label));
5507 emit_jump (default_label);
5511 /* If the index expression is not constant we generate
5512 a binary decision tree to select the appropriate
5513 target code. This is done as follows:
5515 The list of cases is rearranged into a binary tree,
5516 nearly optimal assuming equal probability for each case.
5518 The tree is transformed into RTL, eliminating
5519 redundant test conditions at the same time.
5521 If program flow could reach the end of the
5522 decision tree an unconditional jump to the
5523 default code is emitted. */
5526 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5527 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5528 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5530 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5531 default_label, index_type);
5532 emit_jump_if_reachable (default_label);
5541 enum machine_mode index_mode = SImode;
5542 int index_bits = GET_MODE_BITSIZE (index_mode);
5544 enum machine_mode op_mode;
5546 /* Convert the index to SImode. */
5547 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5548 > GET_MODE_BITSIZE (index_mode))
5550 enum machine_mode omode = TYPE_MODE (index_type);
5551 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5553 /* We must handle the endpoints in the original mode. */
5554 index_expr = build (MINUS_EXPR, index_type,
5555 index_expr, minval);
5556 minval = integer_zero_node;
5557 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5558 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5559 omode, 1, 0, default_label);
5560 /* Now we can safely truncate. */
5561 index = convert_to_mode (index_mode, index, 0);
5565 if (TYPE_MODE (index_type) != index_mode)
5567 index_expr = convert (type_for_size (index_bits, 0),
5569 index_type = TREE_TYPE (index_expr);
5572 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5575 index = protect_from_queue (index, 0);
5576 do_pending_stack_adjust ();
5578 op_mode = insn_data[(int) CODE_FOR_casesi].operand[0].mode;
5579 if (! (*insn_data[(int) CODE_FOR_casesi].operand[0].predicate)
5581 index = copy_to_mode_reg (op_mode, index);
5583 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5585 op_mode = insn_data[(int) CODE_FOR_casesi].operand[1].mode;
5586 if (! (*insn_data[(int) CODE_FOR_casesi].operand[1].predicate)
5588 op1 = copy_to_mode_reg (op_mode, op1);
5590 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5592 op_mode = insn_data[(int) CODE_FOR_casesi].operand[2].mode;
5593 if (! (*insn_data[(int) CODE_FOR_casesi].operand[2].predicate)
5595 op2 = copy_to_mode_reg (op_mode, op2);
5597 emit_jump_insn (gen_casesi (index, op1, op2,
5598 table_label, default_label));
5602 #ifdef HAVE_tablejump
5603 if (! win && HAVE_tablejump)
5605 index_type = thiscase->data.case_stmt.nominal_type;
5606 index_expr = fold (build (MINUS_EXPR, index_type,
5607 convert (index_type, index_expr),
5608 convert (index_type, minval)));
5609 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5611 index = protect_from_queue (index, 0);
5612 do_pending_stack_adjust ();
5614 do_tablejump (index, TYPE_MODE (index_type),
5615 expand_expr (range, NULL_RTX, VOIDmode, 0),
5616 table_label, default_label);
5623 /* Get table of labels to jump to, in order of case index. */
5625 ncases = TREE_INT_CST_LOW (range) + 1;
5626 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5627 memset ((char *) labelvec, 0, ncases * sizeof (rtx));
5629 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5631 register HOST_WIDE_INT i
5632 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5637 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5638 if (i + TREE_INT_CST_LOW (orig_minval)
5639 == TREE_INT_CST_LOW (n->high))
5645 /* Fill in the gaps with the default. */
5646 for (i = 0; i < ncases; i++)
5647 if (labelvec[i] == 0)
5648 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5650 /* Output the table */
5651 emit_label (table_label);
5653 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5654 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5655 gen_rtx_LABEL_REF (Pmode, table_label),
5656 gen_rtvec_v (ncases, labelvec),
5657 const0_rtx, const0_rtx));
5659 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5660 gen_rtvec_v (ncases, labelvec)));
5662 /* If the case insn drops through the table,
5663 after the table we must jump to the default-label.
5664 Otherwise record no drop-through after the table. */
5665 #ifdef CASE_DROPS_THROUGH
5666 emit_jump (default_label);
5672 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5673 reorder_insns (before_case, get_last_insn (),
5674 thiscase->data.case_stmt.start);
5677 end_cleanup_deferral ();
5679 if (thiscase->exit_label)
5680 emit_label (thiscase->exit_label);
5682 free_case_nodes (case_stack->data.case_stmt.case_list);
5683 POPSTACK (case_stack);
5688 /* Convert the tree NODE into a list linked by the right field, with the left
5689 field zeroed. RIGHT is used for recursion; it is a list to be placed
5690 rightmost in the resulting list. */
5692 static struct case_node *
5693 case_tree2list (node, right)
5694 struct case_node *node, *right;
5696 struct case_node *left;
5699 right = case_tree2list (node->right, right);
5701 node->right = right;
5702 if ((left = node->left))
5705 return case_tree2list (left, node);
5711 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5714 do_jump_if_equal (op1, op2, label, unsignedp)
5715 rtx op1, op2, label;
5718 if (GET_CODE (op1) == CONST_INT
5719 && GET_CODE (op2) == CONST_INT)
5721 if (INTVAL (op1) == INTVAL (op2))
5726 enum machine_mode mode = GET_MODE (op1);
5727 if (mode == VOIDmode)
5728 mode = GET_MODE (op2);
5729 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5734 /* Not all case values are encountered equally. This function
5735 uses a heuristic to weight case labels, in cases where that
5736 looks like a reasonable thing to do.
5738 Right now, all we try to guess is text, and we establish the
5741 chars above space: 16
5750 If we find any cases in the switch that are not either -1 or in the range
5751 of valid ASCII characters, or are control characters other than those
5752 commonly used with "\", don't treat this switch scanning text.
5754 Return 1 if these nodes are suitable for cost estimation, otherwise
5758 estimate_case_costs (node)
5761 tree min_ascii = build_int_2 (-1, -1);
5762 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5766 /* If we haven't already made the cost table, make it now. Note that the
5767 lower bound of the table is -1, not zero. */
5769 if (cost_table == NULL)
5771 cost_table = cost_table_ + 1;
5773 for (i = 0; i < 128; i++)
5777 else if (ISPUNCT (i))
5779 else if (ISCNTRL (i))
5783 cost_table[' '] = 8;
5784 cost_table['\t'] = 4;
5785 cost_table['\0'] = 4;
5786 cost_table['\n'] = 2;
5787 cost_table['\f'] = 1;
5788 cost_table['\v'] = 1;
5789 cost_table['\b'] = 1;
5792 /* See if all the case expressions look like text. It is text if the
5793 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5794 as signed arithmetic since we don't want to ever access cost_table with a
5795 value less than -1. Also check that none of the constants in a range
5796 are strange control characters. */
5798 for (n = node; n; n = n->right)
5800 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5803 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5804 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5805 if (cost_table[i] < 0)
5809 /* All interesting values are within the range of interesting
5810 ASCII characters. */
5814 /* Scan an ordered list of case nodes
5815 combining those with consecutive values or ranges.
5817 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5820 group_case_nodes (head)
5823 case_node_ptr node = head;
5827 rtx lb = next_real_insn (label_rtx (node->code_label));
5829 case_node_ptr np = node;
5831 /* Try to group the successors of NODE with NODE. */
5832 while (((np = np->right) != 0)
5833 /* Do they jump to the same place? */
5834 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5835 || (lb != 0 && lb2 != 0
5836 && simplejump_p (lb)
5837 && simplejump_p (lb2)
5838 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5839 SET_SRC (PATTERN (lb2)))))
5840 /* Are their ranges consecutive? */
5841 && tree_int_cst_equal (np->low,
5842 fold (build (PLUS_EXPR,
5843 TREE_TYPE (node->high),
5846 /* An overflow is not consecutive. */
5847 && tree_int_cst_lt (node->high,
5848 fold (build (PLUS_EXPR,
5849 TREE_TYPE (node->high),
5851 integer_one_node))))
5853 node->high = np->high;
5855 /* NP is the first node after NODE which can't be grouped with it.
5856 Delete the nodes in between, and move on to that node. */
5862 /* Take an ordered list of case nodes
5863 and transform them into a near optimal binary tree,
5864 on the assumption that any target code selection value is as
5865 likely as any other.
5867 The transformation is performed by splitting the ordered
5868 list into two equal sections plus a pivot. The parts are
5869 then attached to the pivot as left and right branches. Each
5870 branch is then transformed recursively. */
5873 balance_case_nodes (head, parent)
5874 case_node_ptr *head;
5875 case_node_ptr parent;
5877 register case_node_ptr np;
5885 register case_node_ptr *npp;
5888 /* Count the number of entries on branch. Also count the ranges. */
5892 if (!tree_int_cst_equal (np->low, np->high))
5896 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5900 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5908 /* Split this list if it is long enough for that to help. */
5913 /* Find the place in the list that bisects the list's total cost,
5914 Here I gets half the total cost. */
5919 /* Skip nodes while their cost does not reach that amount. */
5920 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5921 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5922 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5925 npp = &(*npp)->right;
5930 /* Leave this branch lopsided, but optimize left-hand
5931 side and fill in `parent' fields for right-hand side. */
5933 np->parent = parent;
5934 balance_case_nodes (&np->left, np);
5935 for (; np->right; np = np->right)
5936 np->right->parent = np;
5940 /* If there are just three nodes, split at the middle one. */
5942 npp = &(*npp)->right;
5945 /* Find the place in the list that bisects the list's total cost,
5946 where ranges count as 2.
5947 Here I gets half the total cost. */
5948 i = (i + ranges + 1) / 2;
5951 /* Skip nodes while their cost does not reach that amount. */
5952 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5957 npp = &(*npp)->right;
5962 np->parent = parent;
5965 /* Optimize each of the two split parts. */
5966 balance_case_nodes (&np->left, np);
5967 balance_case_nodes (&np->right, np);
5971 /* Else leave this branch as one level,
5972 but fill in `parent' fields. */
5974 np->parent = parent;
5975 for (; np->right; np = np->right)
5976 np->right->parent = np;
5981 /* Search the parent sections of the case node tree
5982 to see if a test for the lower bound of NODE would be redundant.
5983 INDEX_TYPE is the type of the index expression.
5985 The instructions to generate the case decision tree are
5986 output in the same order as nodes are processed so it is
5987 known that if a parent node checks the range of the current
5988 node minus one that the current node is bounded at its lower
5989 span. Thus the test would be redundant. */
5992 node_has_low_bound (node, index_type)
5997 case_node_ptr pnode;
5999 /* If the lower bound of this node is the lowest value in the index type,
6000 we need not test it. */
6002 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
6005 /* If this node has a left branch, the value at the left must be less
6006 than that at this node, so it cannot be bounded at the bottom and
6007 we need not bother testing any further. */
6012 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
6013 node->low, integer_one_node));
6015 /* If the subtraction above overflowed, we can't verify anything.
6016 Otherwise, look for a parent that tests our value - 1. */
6018 if (! tree_int_cst_lt (low_minus_one, node->low))
6021 for (pnode = node->parent; pnode; pnode = pnode->parent)
6022 if (tree_int_cst_equal (low_minus_one, pnode->high))
6028 /* Search the parent sections of the case node tree
6029 to see if a test for the upper bound of NODE would be redundant.
6030 INDEX_TYPE is the type of the index expression.
6032 The instructions to generate the case decision tree are
6033 output in the same order as nodes are processed so it is
6034 known that if a parent node checks the range of the current
6035 node plus one that the current node is bounded at its upper
6036 span. Thus the test would be redundant. */
6039 node_has_high_bound (node, index_type)
6044 case_node_ptr pnode;
6046 /* If there is no upper bound, obviously no test is needed. */
6048 if (TYPE_MAX_VALUE (index_type) == NULL)
6051 /* If the upper bound of this node is the highest value in the type
6052 of the index expression, we need not test against it. */
6054 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6057 /* If this node has a right branch, the value at the right must be greater
6058 than that at this node, so it cannot be bounded at the top and
6059 we need not bother testing any further. */
6064 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6065 node->high, integer_one_node));
6067 /* If the addition above overflowed, we can't verify anything.
6068 Otherwise, look for a parent that tests our value + 1. */
6070 if (! tree_int_cst_lt (node->high, high_plus_one))
6073 for (pnode = node->parent; pnode; pnode = pnode->parent)
6074 if (tree_int_cst_equal (high_plus_one, pnode->low))
6080 /* Search the parent sections of the
6081 case node tree to see if both tests for the upper and lower
6082 bounds of NODE would be redundant. */
6085 node_is_bounded (node, index_type)
6089 return (node_has_low_bound (node, index_type)
6090 && node_has_high_bound (node, index_type));
6093 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6096 emit_jump_if_reachable (label)
6099 if (GET_CODE (get_last_insn ()) != BARRIER)
6103 /* Emit step-by-step code to select a case for the value of INDEX.
6104 The thus generated decision tree follows the form of the
6105 case-node binary tree NODE, whose nodes represent test conditions.
6106 INDEX_TYPE is the type of the index of the switch.
6108 Care is taken to prune redundant tests from the decision tree
6109 by detecting any boundary conditions already checked by
6110 emitted rtx. (See node_has_high_bound, node_has_low_bound
6111 and node_is_bounded, above.)
6113 Where the test conditions can be shown to be redundant we emit
6114 an unconditional jump to the target code. As a further
6115 optimization, the subordinates of a tree node are examined to
6116 check for bounded nodes. In this case conditional and/or
6117 unconditional jumps as a result of the boundary check for the
6118 current node are arranged to target the subordinates associated
6119 code for out of bound conditions on the current node.
6121 We can assume that when control reaches the code generated here,
6122 the index value has already been compared with the parents
6123 of this node, and determined to be on the same side of each parent
6124 as this node is. Thus, if this node tests for the value 51,
6125 and a parent tested for 52, we don't need to consider
6126 the possibility of a value greater than 51. If another parent
6127 tests for the value 50, then this node need not test anything. */
6130 emit_case_nodes (index, node, default_label, index_type)
6136 /* If INDEX has an unsigned type, we must make unsigned branches. */
6137 int unsignedp = TREE_UNSIGNED (index_type);
6138 enum machine_mode mode = GET_MODE (index);
6140 /* See if our parents have already tested everything for us.
6141 If they have, emit an unconditional jump for this node. */
6142 if (node_is_bounded (node, index_type))
6143 emit_jump (label_rtx (node->code_label));
6145 else if (tree_int_cst_equal (node->low, node->high))
6147 /* Node is single valued. First see if the index expression matches
6148 this node and then check our children, if any. */
6150 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6151 label_rtx (node->code_label), unsignedp);
6153 if (node->right != 0 && node->left != 0)
6155 /* This node has children on both sides.
6156 Dispatch to one side or the other
6157 by comparing the index value with this node's value.
6158 If one subtree is bounded, check that one first,
6159 so we can avoid real branches in the tree. */
6161 if (node_is_bounded (node->right, index_type))
6163 emit_cmp_and_jump_insns (index,
6164 expand_expr (node->high, NULL_RTX,
6166 GT, NULL_RTX, mode, unsignedp, 0,
6167 label_rtx (node->right->code_label));
6168 emit_case_nodes (index, node->left, default_label, index_type);
6171 else if (node_is_bounded (node->left, index_type))
6173 emit_cmp_and_jump_insns (index,
6174 expand_expr (node->high, NULL_RTX,
6176 LT, NULL_RTX, mode, unsignedp, 0,
6177 label_rtx (node->left->code_label));
6178 emit_case_nodes (index, node->right, default_label, index_type);
6183 /* Neither node is bounded. First distinguish the two sides;
6184 then emit the code for one side at a time. */
6186 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6188 /* See if the value is on the right. */
6189 emit_cmp_and_jump_insns (index,
6190 expand_expr (node->high, NULL_RTX,
6192 GT, NULL_RTX, mode, unsignedp, 0,
6193 label_rtx (test_label));
6195 /* Value must be on the left.
6196 Handle the left-hand subtree. */
6197 emit_case_nodes (index, node->left, default_label, index_type);
6198 /* If left-hand subtree does nothing,
6200 emit_jump_if_reachable (default_label);
6202 /* Code branches here for the right-hand subtree. */
6203 expand_label (test_label);
6204 emit_case_nodes (index, node->right, default_label, index_type);
6208 else if (node->right != 0 && node->left == 0)
6210 /* Here we have a right child but no left so we issue conditional
6211 branch to default and process the right child.
6213 Omit the conditional branch to default if we it avoid only one
6214 right child; it costs too much space to save so little time. */
6216 if (node->right->right || node->right->left
6217 || !tree_int_cst_equal (node->right->low, node->right->high))
6219 if (!node_has_low_bound (node, index_type))
6221 emit_cmp_and_jump_insns (index,
6222 expand_expr (node->high, NULL_RTX,
6224 LT, NULL_RTX, mode, unsignedp, 0,
6228 emit_case_nodes (index, node->right, default_label, index_type);
6231 /* We cannot process node->right normally
6232 since we haven't ruled out the numbers less than
6233 this node's value. So handle node->right explicitly. */
6234 do_jump_if_equal (index,
6235 expand_expr (node->right->low, NULL_RTX,
6237 label_rtx (node->right->code_label), unsignedp);
6240 else if (node->right == 0 && node->left != 0)
6242 /* Just one subtree, on the left. */
6244 #if 0 /* The following code and comment were formerly part
6245 of the condition here, but they didn't work
6246 and I don't understand what the idea was. -- rms. */
6247 /* If our "most probable entry" is less probable
6248 than the default label, emit a jump to
6249 the default label using condition codes
6250 already lying around. With no right branch,
6251 a branch-greater-than will get us to the default
6254 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6257 if (node->left->left || node->left->right
6258 || !tree_int_cst_equal (node->left->low, node->left->high))
6260 if (!node_has_high_bound (node, index_type))
6262 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6265 GT, NULL_RTX, mode, unsignedp, 0,
6269 emit_case_nodes (index, node->left, default_label, index_type);
6272 /* We cannot process node->left normally
6273 since we haven't ruled out the numbers less than
6274 this node's value. So handle node->left explicitly. */
6275 do_jump_if_equal (index,
6276 expand_expr (node->left->low, NULL_RTX,
6278 label_rtx (node->left->code_label), unsignedp);
6283 /* Node is a range. These cases are very similar to those for a single
6284 value, except that we do not start by testing whether this node
6285 is the one to branch to. */
6287 if (node->right != 0 && node->left != 0)
6289 /* Node has subtrees on both sides.
6290 If the right-hand subtree is bounded,
6291 test for it first, since we can go straight there.
6292 Otherwise, we need to make a branch in the control structure,
6293 then handle the two subtrees. */
6294 tree test_label = 0;
6296 if (node_is_bounded (node->right, index_type))
6297 /* Right hand node is fully bounded so we can eliminate any
6298 testing and branch directly to the target code. */
6299 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6301 GT, NULL_RTX, mode, unsignedp, 0,
6302 label_rtx (node->right->code_label));
6305 /* Right hand node requires testing.
6306 Branch to a label where we will handle it later. */
6308 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6309 emit_cmp_and_jump_insns (index,
6310 expand_expr (node->high, NULL_RTX,
6312 GT, NULL_RTX, mode, unsignedp, 0,
6313 label_rtx (test_label));
6316 /* Value belongs to this node or to the left-hand subtree. */
6318 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6320 GE, NULL_RTX, mode, unsignedp, 0,
6321 label_rtx (node->code_label));
6323 /* Handle the left-hand subtree. */
6324 emit_case_nodes (index, node->left, default_label, index_type);
6326 /* If right node had to be handled later, do that now. */
6330 /* If the left-hand subtree fell through,
6331 don't let it fall into the right-hand subtree. */
6332 emit_jump_if_reachable (default_label);
6334 expand_label (test_label);
6335 emit_case_nodes (index, node->right, default_label, index_type);
6339 else if (node->right != 0 && node->left == 0)
6341 /* Deal with values to the left of this node,
6342 if they are possible. */
6343 if (!node_has_low_bound (node, index_type))
6345 emit_cmp_and_jump_insns (index,
6346 expand_expr (node->low, NULL_RTX,
6348 LT, NULL_RTX, mode, unsignedp, 0,
6352 /* Value belongs to this node or to the right-hand subtree. */
6354 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6356 LE, NULL_RTX, mode, unsignedp, 0,
6357 label_rtx (node->code_label));
6359 emit_case_nodes (index, node->right, default_label, index_type);
6362 else if (node->right == 0 && node->left != 0)
6364 /* Deal with values to the right of this node,
6365 if they are possible. */
6366 if (!node_has_high_bound (node, index_type))
6368 emit_cmp_and_jump_insns (index,
6369 expand_expr (node->high, NULL_RTX,
6371 GT, NULL_RTX, mode, unsignedp, 0,
6375 /* Value belongs to this node or to the left-hand subtree. */
6377 emit_cmp_and_jump_insns (index,
6378 expand_expr (node->low, NULL_RTX,
6380 GE, NULL_RTX, mode, unsignedp, 0,
6381 label_rtx (node->code_label));
6383 emit_case_nodes (index, node->left, default_label, index_type);
6388 /* Node has no children so we check low and high bounds to remove
6389 redundant tests. Only one of the bounds can exist,
6390 since otherwise this node is bounded--a case tested already. */
6392 if (!node_has_high_bound (node, index_type))
6394 emit_cmp_and_jump_insns (index,
6395 expand_expr (node->high, NULL_RTX,
6397 GT, NULL_RTX, mode, unsignedp, 0,
6401 if (!node_has_low_bound (node, index_type))
6403 emit_cmp_and_jump_insns (index,
6404 expand_expr (node->low, NULL_RTX,
6406 LT, NULL_RTX, mode, unsignedp, 0,
6410 emit_jump (label_rtx (node->code_label));