1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
23 /* This file handles the generation of rtl code from tree structure
24 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
25 It also creates the rtl expressions for parameters and auto variables
26 and has full responsibility for allocating stack slots.
28 The functions whose names start with `expand_' are called by the
29 parser to generate RTL instructions for various kinds of constructs.
31 Some control and binding constructs require calling several such
32 functions at different times. For example, a simple if-then
33 is expanded by calling `expand_start_cond' (with the condition-expression
34 as argument) before parsing the then-clause and calling `expand_end_cond'
35 after parsing the then-clause. */
46 #include "insn-flags.h"
47 #include "insn-config.h"
48 #include "insn-codes.h"
50 #include "hard-reg-set.h"
59 #define obstack_chunk_alloc xmalloc
60 #define obstack_chunk_free free
61 struct obstack stmt_obstack;
63 /* Assume that case vectors are not pc-relative. */
64 #ifndef CASE_VECTOR_PC_RELATIVE
65 #define CASE_VECTOR_PC_RELATIVE 0
69 /* Functions and data structures for expanding case statements. */
71 /* Case label structure, used to hold info on labels within case
72 statements. We handle "range" labels; for a single-value label
73 as in C, the high and low limits are the same.
75 An AVL tree of case nodes is initially created, and later transformed
76 to a list linked via the RIGHT fields in the nodes. Nodes with
77 higher case values are later in the list.
79 Switch statements can be output in one of two forms. A branch table
80 is used if there are more than a few labels and the labels are dense
81 within the range between the smallest and largest case value. If a
82 branch table is used, no further manipulations are done with the case
85 The alternative to the use of a branch table is to generate a series
86 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
87 and PARENT fields to hold a binary tree. Initially the tree is
88 totally unbalanced, with everything on the right. We balance the tree
89 with nodes on the left having lower case values than the parent
90 and nodes on the right having higher values. We then output the tree
95 struct case_node *left; /* Left son in binary tree */
96 struct case_node *right; /* Right son in binary tree; also node chain */
97 struct case_node *parent; /* Parent of node in binary tree */
98 tree low; /* Lowest index value for this label */
99 tree high; /* Highest index value for this label */
100 tree code_label; /* Label to jump to when node matches */
104 typedef struct case_node case_node;
105 typedef struct case_node *case_node_ptr;
107 /* These are used by estimate_case_costs and balance_case_nodes. */
109 /* This must be a signed type, and non-ANSI compilers lack signed char. */
110 static short cost_table_[129];
111 static short *cost_table;
112 static int use_cost_table;
114 /* Stack of control and binding constructs we are currently inside.
116 These constructs begin when you call `expand_start_WHATEVER'
117 and end when you call `expand_end_WHATEVER'. This stack records
118 info about how the construct began that tells the end-function
119 what to do. It also may provide information about the construct
120 to alter the behavior of other constructs within the body.
121 For example, they may affect the behavior of C `break' and `continue'.
123 Each construct gets one `struct nesting' object.
124 All of these objects are chained through the `all' field.
125 `nesting_stack' points to the first object (innermost construct).
126 The position of an entry on `nesting_stack' is in its `depth' field.
128 Each type of construct has its own individual stack.
129 For example, loops have `loop_stack'. Each object points to the
130 next object of the same type through the `next' field.
132 Some constructs are visible to `break' exit-statements and others
133 are not. Which constructs are visible depends on the language.
134 Therefore, the data structure allows each construct to be visible
135 or not, according to the args given when the construct is started.
136 The construct is visible if the `exit_label' field is non-null.
137 In that case, the value should be a CODE_LABEL rtx. */
142 struct nesting *next;
147 /* For conds (if-then and if-then-else statements). */
150 /* Label for the end of the if construct.
151 There is none if EXITFLAG was not set
152 and no `else' has been seen yet. */
154 /* Label for the end of this alternative.
155 This may be the end of the if or the next else/elseif. */
161 /* Label at the top of the loop; place to loop back to. */
163 /* Label at the end of the whole construct. */
165 /* Label before a jump that branches to the end of the whole
166 construct. This is where destructors go if any. */
168 /* Label for `continue' statement to jump to;
169 this is in front of the stepper of the loop. */
172 /* For variable binding contours. */
175 /* Sequence number of this binding contour within the function,
176 in order of entry. */
177 int block_start_count;
178 /* Nonzero => value to restore stack to on exit. */
180 /* The NOTE that starts this contour.
181 Used by expand_goto to check whether the destination
182 is within each contour or not. */
184 /* Innermost containing binding contour that has a stack level. */
185 struct nesting *innermost_stack_block;
186 /* List of cleanups to be run on exit from this contour.
187 This is a list of expressions to be evaluated.
188 The TREE_PURPOSE of each link is the ..._DECL node
189 which the cleanup pertains to. */
191 /* List of cleanup-lists of blocks containing this block,
192 as they were at the locus where this block appears.
193 There is an element for each containing block,
194 ordered innermost containing block first.
195 The tail of this list can be 0,
196 if all remaining elements would be empty lists.
197 The element's TREE_VALUE is the cleanup-list of that block,
198 which may be null. */
200 /* Chain of labels defined inside this binding contour.
201 For contours that have stack levels or cleanups. */
202 struct label_chain *label_chain;
203 /* Number of function calls seen, as of start of this block. */
204 int n_function_calls;
205 /* Nonzero if this is associated with a EH region. */
206 int exception_region;
207 /* The saved target_temp_slot_level from our outer block.
208 We may reset target_temp_slot_level to be the level of
209 this block, if that is done, target_temp_slot_level
210 reverts to the saved target_temp_slot_level at the very
212 int block_target_temp_slot_level;
213 /* True if we are currently emitting insns in an area of
214 output code that is controlled by a conditional
215 expression. This is used by the cleanup handling code to
216 generate conditional cleanup actions. */
217 int conditional_code;
218 /* A place to move the start of the exception region for any
219 of the conditional cleanups, must be at the end or after
220 the start of the last unconditional cleanup, and before any
221 conditional branch points. */
222 rtx last_unconditional_cleanup;
223 /* When in a conditional context, this is the specific
224 cleanup list associated with last_unconditional_cleanup,
225 where we place the conditionalized cleanups. */
228 /* For switch (C) or case (Pascal) statements,
229 and also for dummies (see `expand_start_case_dummy'). */
232 /* The insn after which the case dispatch should finally
233 be emitted. Zero for a dummy. */
235 /* A list of case labels; it is first built as an AVL tree.
236 During expand_end_case, this is converted to a list, and may be
237 rearranged into a nearly balanced binary tree. */
238 struct case_node *case_list;
239 /* Label to jump to if no case matches. */
241 /* The expression to be dispatched on. */
243 /* Type that INDEX_EXPR should be converted to. */
245 /* Number of range exprs in case statement. */
247 /* Name of this kind of statement, for warnings. */
248 const char *printname;
249 /* Used to save no_line_numbers till we see the first case label.
250 We set this to -1 when we see the first case label in this
252 int line_number_status;
257 /* Allocate and return a new `struct nesting'. */
259 #define ALLOC_NESTING() \
260 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
262 /* Pop the nesting stack element by element until we pop off
263 the element which is at the top of STACK.
264 Update all the other stacks, popping off elements from them
265 as we pop them from nesting_stack. */
267 #define POPSTACK(STACK) \
268 do { struct nesting *target = STACK; \
269 struct nesting *this; \
270 do { this = nesting_stack; \
271 if (loop_stack == this) \
272 loop_stack = loop_stack->next; \
273 if (cond_stack == this) \
274 cond_stack = cond_stack->next; \
275 if (block_stack == this) \
276 block_stack = block_stack->next; \
277 if (stack_block_stack == this) \
278 stack_block_stack = stack_block_stack->next; \
279 if (case_stack == this) \
280 case_stack = case_stack->next; \
281 nesting_depth = nesting_stack->depth - 1; \
282 nesting_stack = this->all; \
283 obstack_free (&stmt_obstack, this); } \
284 while (this != target); } while (0)
286 /* In some cases it is impossible to generate code for a forward goto
287 until the label definition is seen. This happens when it may be necessary
288 for the goto to reset the stack pointer: we don't yet know how to do that.
289 So expand_goto puts an entry on this fixup list.
290 Each time a binding contour that resets the stack is exited,
292 If the target label has now been defined, we can insert the proper code. */
296 /* Points to following fixup. */
297 struct goto_fixup *next;
298 /* Points to the insn before the jump insn.
299 If more code must be inserted, it goes after this insn. */
301 /* The LABEL_DECL that this jump is jumping to, or 0
302 for break, continue or return. */
304 /* The BLOCK for the place where this goto was found. */
306 /* The CODE_LABEL rtx that this is jumping to. */
308 /* Number of binding contours started in current function
309 before the label reference. */
310 int block_start_count;
311 /* The outermost stack level that should be restored for this jump.
312 Each time a binding contour that resets the stack is exited,
313 if the target label is *not* yet defined, this slot is updated. */
315 /* List of lists of cleanup expressions to be run by this goto.
316 There is one element for each block that this goto is within.
317 The tail of this list can be 0,
318 if all remaining elements would be empty.
319 The TREE_VALUE contains the cleanup list of that block as of the
320 time this goto was seen.
321 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
322 tree cleanup_list_list;
325 /* Within any binding contour that must restore a stack level,
326 all labels are recorded with a chain of these structures. */
330 /* Points to following fixup. */
331 struct label_chain *next;
337 /* Chain of all pending binding contours. */
338 struct nesting *x_block_stack;
340 /* If any new stacks are added here, add them to POPSTACKS too. */
342 /* Chain of all pending binding contours that restore stack levels
344 struct nesting *x_stack_block_stack;
346 /* Chain of all pending conditional statements. */
347 struct nesting *x_cond_stack;
349 /* Chain of all pending loops. */
350 struct nesting *x_loop_stack;
352 /* Chain of all pending case or switch statements. */
353 struct nesting *x_case_stack;
355 /* Separate chain including all of the above,
356 chained through the `all' field. */
357 struct nesting *x_nesting_stack;
359 /* Number of entries on nesting_stack now. */
362 /* Number of binding contours started so far in this function. */
363 int x_block_start_count;
365 /* Each time we expand an expression-statement,
366 record the expr's type and its RTL value here. */
367 tree x_last_expr_type;
368 rtx x_last_expr_value;
370 /* Nonzero if within a ({...}) grouping, in which case we must
371 always compute a value for each expr-stmt in case it is the last one. */
372 int x_expr_stmts_for_value;
374 /* Filename and line number of last line-number note,
375 whether we actually emitted it or not. */
376 const char *x_emit_filename;
379 struct goto_fixup *x_goto_fixup_chain;
382 #define block_stack (cfun->stmt->x_block_stack)
383 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
384 #define cond_stack (cfun->stmt->x_cond_stack)
385 #define loop_stack (cfun->stmt->x_loop_stack)
386 #define case_stack (cfun->stmt->x_case_stack)
387 #define nesting_stack (cfun->stmt->x_nesting_stack)
388 #define nesting_depth (cfun->stmt->x_nesting_depth)
389 #define current_block_start_count (cfun->stmt->x_block_start_count)
390 #define last_expr_type (cfun->stmt->x_last_expr_type)
391 #define last_expr_value (cfun->stmt->x_last_expr_value)
392 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
393 #define emit_filename (cfun->stmt->x_emit_filename)
394 #define emit_lineno (cfun->stmt->x_emit_lineno)
395 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
397 /* Non-zero if we are using EH to handle cleanus. */
398 static int using_eh_for_cleanups_p = 0;
400 /* Character strings, each containing a single decimal digit. */
401 static char *digit_strings[10];
404 static int n_occurrences PARAMS ((int, const char *));
405 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
406 static int expand_fixup PARAMS ((tree, rtx, rtx));
407 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
408 static void expand_nl_goto_receiver PARAMS ((void));
409 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
410 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
412 static void expand_null_return_1 PARAMS ((rtx, int));
413 static void expand_value_return PARAMS ((rtx));
414 static int tail_recursion_args PARAMS ((tree, tree));
415 static void expand_cleanups PARAMS ((tree, tree, int, int));
416 static void check_seenlabel PARAMS ((void));
417 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
418 static int estimate_case_costs PARAMS ((case_node_ptr));
419 static void group_case_nodes PARAMS ((case_node_ptr));
420 static void balance_case_nodes PARAMS ((case_node_ptr *,
422 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
423 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
424 static int node_is_bounded PARAMS ((case_node_ptr, tree));
425 static void emit_jump_if_reachable PARAMS ((rtx));
426 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
427 static int add_case_node PARAMS ((tree, tree, tree, tree *));
428 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
429 static void mark_cond_nesting PARAMS ((struct nesting *));
430 static void mark_loop_nesting PARAMS ((struct nesting *));
431 static void mark_block_nesting PARAMS ((struct nesting *));
432 static void mark_case_nesting PARAMS ((struct nesting *));
433 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
437 using_eh_for_cleanups ()
439 using_eh_for_cleanups_p = 1;
442 /* Mark N (known to be a cond-nesting) for GC. */
445 mark_cond_nesting (n)
450 ggc_mark_rtx (n->exit_label);
451 ggc_mark_rtx (n->data.cond.endif_label);
452 ggc_mark_rtx (n->data.cond.next_label);
458 /* Mark N (known to be a loop-nesting) for GC. */
461 mark_loop_nesting (n)
467 ggc_mark_rtx (n->exit_label);
468 ggc_mark_rtx (n->data.loop.start_label);
469 ggc_mark_rtx (n->data.loop.end_label);
470 ggc_mark_rtx (n->data.loop.alt_end_label);
471 ggc_mark_rtx (n->data.loop.continue_label);
477 /* Mark N (known to be a block-nesting) for GC. */
480 mark_block_nesting (n)
485 struct label_chain *l;
487 ggc_mark_rtx (n->exit_label);
488 ggc_mark_rtx (n->data.block.stack_level);
489 ggc_mark_rtx (n->data.block.first_insn);
490 ggc_mark_tree (n->data.block.cleanups);
491 ggc_mark_tree (n->data.block.outer_cleanups);
493 for (l = n->data.block.label_chain; l != NULL; l = l->next)
494 ggc_mark_tree (l->label);
496 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
498 /* ??? cleanup_ptr never points outside the stack, does it? */
504 /* Mark N (known to be a case-nesting) for GC. */
507 mark_case_nesting (n)
512 struct case_node *node;
514 ggc_mark_rtx (n->exit_label);
515 ggc_mark_rtx (n->data.case_stmt.start);
517 node = n->data.case_stmt.case_list;
520 ggc_mark_tree (node->low);
521 ggc_mark_tree (node->high);
522 ggc_mark_tree (node->code_label);
526 ggc_mark_tree (n->data.case_stmt.default_label);
527 ggc_mark_tree (n->data.case_stmt.index_expr);
528 ggc_mark_tree (n->data.case_stmt.nominal_type);
538 struct goto_fixup *g;
542 ggc_mark_rtx (g->before_jump);
543 ggc_mark_tree (g->target);
544 ggc_mark_tree (g->context);
545 ggc_mark_rtx (g->target_rtl);
546 ggc_mark_rtx (g->stack_level);
547 ggc_mark_tree (g->cleanup_list_list);
553 /* Clear out all parts of the state in F that can safely be discarded
554 after the function has been compiled, to let garbage collection
555 reclaim the memory. */
561 /* We're about to free the function obstack. If we hold pointers to
562 things allocated there, then we'll try to mark them when we do
563 GC. So, we clear them out here explicitly. */
573 struct stmt_status *p;
578 mark_block_nesting (p->x_block_stack);
579 mark_cond_nesting (p->x_cond_stack);
580 mark_loop_nesting (p->x_loop_stack);
581 mark_case_nesting (p->x_case_stack);
583 ggc_mark_tree (p->x_last_expr_type);
584 /* last_epxr_value is only valid if last_expr_type is nonzero. */
585 if (p->x_last_expr_type)
586 ggc_mark_rtx (p->x_last_expr_value);
588 mark_goto_fixup (p->x_goto_fixup_chain);
596 gcc_obstack_init (&stmt_obstack);
598 for (i = 0; i < 10; i++)
600 digit_strings[i] = ggc_alloc_string (NULL, 1);
601 digit_strings[i][0] = '0' + i;
603 ggc_add_string_root (digit_strings, 10);
607 init_stmt_for_function ()
609 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
611 /* We are not currently within any block, conditional, loop or case. */
613 stack_block_stack = 0;
620 current_block_start_count = 0;
622 /* No gotos have been expanded yet. */
623 goto_fixup_chain = 0;
625 /* We are not processing a ({...}) grouping. */
626 expr_stmts_for_value = 0;
628 last_expr_value = NULL_RTX;
631 /* Return nonzero if anything is pushed on the loop, condition, or case
636 return cond_stack || loop_stack || case_stack;
639 /* Record the current file and line. Called from emit_line_note. */
641 set_file_and_line_for_stmt (file, line)
645 /* If we're outputting an inline function, and we add a line note,
646 there may be no CFUN->STMT information. So, there's no need to
650 emit_filename = file;
655 /* Emit a no-op instruction. */
662 last_insn = get_last_insn ();
664 && (GET_CODE (last_insn) == CODE_LABEL
665 || (GET_CODE (last_insn) == NOTE
666 && prev_real_insn (last_insn) == 0)))
667 emit_insn (gen_nop ());
670 /* Return the rtx-label that corresponds to a LABEL_DECL,
671 creating it if necessary. */
677 if (TREE_CODE (label) != LABEL_DECL)
680 if (DECL_RTL (label))
681 return DECL_RTL (label);
683 return DECL_RTL (label) = gen_label_rtx ();
686 /* Add an unconditional jump to LABEL as the next sequential instruction. */
692 do_pending_stack_adjust ();
693 emit_jump_insn (gen_jump (label));
697 /* Emit code to jump to the address
698 specified by the pointer expression EXP. */
701 expand_computed_goto (exp)
704 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
706 #ifdef POINTERS_EXTEND_UNSIGNED
707 x = convert_memory_address (Pmode, x);
711 /* Be sure the function is executable. */
712 if (current_function_check_memory_usage)
713 emit_library_call (chkr_check_exec_libfunc, 1,
714 VOIDmode, 1, x, ptr_mode);
716 do_pending_stack_adjust ();
717 emit_indirect_jump (x);
719 current_function_has_computed_jump = 1;
722 /* Handle goto statements and the labels that they can go to. */
724 /* Specify the location in the RTL code of a label LABEL,
725 which is a LABEL_DECL tree node.
727 This is used for the kind of label that the user can jump to with a
728 goto statement, and for alternatives of a switch or case statement.
729 RTL labels generated for loops and conditionals don't go through here;
730 they are generated directly at the RTL level, by other functions below.
732 Note that this has nothing to do with defining label *names*.
733 Languages vary in how they do that and what that even means. */
739 struct label_chain *p;
741 do_pending_stack_adjust ();
742 emit_label (label_rtx (label));
743 if (DECL_NAME (label))
744 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
746 if (stack_block_stack != 0)
748 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
749 p->next = stack_block_stack->data.block.label_chain;
750 stack_block_stack->data.block.label_chain = p;
755 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
756 from nested functions. */
759 declare_nonlocal_label (label)
762 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
764 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
765 LABEL_PRESERVE_P (label_rtx (label)) = 1;
766 if (nonlocal_goto_handler_slots == 0)
768 emit_stack_save (SAVE_NONLOCAL,
769 &nonlocal_goto_stack_level,
770 PREV_INSN (tail_recursion_reentry));
772 nonlocal_goto_handler_slots
773 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
776 /* Generate RTL code for a `goto' statement with target label LABEL.
777 LABEL should be a LABEL_DECL tree node that was or will later be
778 defined with `expand_label'. */
786 /* Check for a nonlocal goto to a containing function. */
787 context = decl_function_context (label);
788 if (context != 0 && context != current_function_decl)
790 struct function *p = find_function_data (context);
791 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
792 rtx temp, handler_slot;
795 /* Find the corresponding handler slot for this label. */
796 handler_slot = p->x_nonlocal_goto_handler_slots;
797 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
798 link = TREE_CHAIN (link))
799 handler_slot = XEXP (handler_slot, 1);
800 handler_slot = XEXP (handler_slot, 0);
802 p->has_nonlocal_label = 1;
803 current_function_has_nonlocal_goto = 1;
804 LABEL_REF_NONLOCAL_P (label_ref) = 1;
806 /* Copy the rtl for the slots so that they won't be shared in
807 case the virtual stack vars register gets instantiated differently
808 in the parent than in the child. */
810 #if HAVE_nonlocal_goto
811 if (HAVE_nonlocal_goto)
812 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
813 copy_rtx (handler_slot),
814 copy_rtx (p->x_nonlocal_goto_stack_level),
821 /* Restore frame pointer for containing function.
822 This sets the actual hard register used for the frame pointer
823 to the location of the function's incoming static chain info.
824 The non-local goto handler will then adjust it to contain the
825 proper value and reload the argument pointer, if needed. */
826 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
828 /* We have now loaded the frame pointer hardware register with
829 the address of that corresponds to the start of the virtual
830 stack vars. So replace virtual_stack_vars_rtx in all
831 addresses we use with stack_pointer_rtx. */
833 /* Get addr of containing function's current nonlocal goto handler,
834 which will do any cleanups and then jump to the label. */
835 addr = copy_rtx (handler_slot);
836 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
837 hard_frame_pointer_rtx));
839 /* Restore the stack pointer. Note this uses fp just restored. */
840 addr = p->x_nonlocal_goto_stack_level;
842 addr = replace_rtx (copy_rtx (addr),
843 virtual_stack_vars_rtx,
844 hard_frame_pointer_rtx);
846 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
848 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
850 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
851 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
852 emit_indirect_jump (temp);
856 expand_goto_internal (label, label_rtx (label), NULL_RTX);
859 /* Generate RTL code for a `goto' statement with target label BODY.
860 LABEL should be a LABEL_REF.
861 LAST_INSN, if non-0, is the rtx we should consider as the last
862 insn emitted (for the purposes of cleaning up a return). */
865 expand_goto_internal (body, label, last_insn)
870 struct nesting *block;
873 if (GET_CODE (label) != CODE_LABEL)
876 /* If label has already been defined, we can tell now
877 whether and how we must alter the stack level. */
879 if (PREV_INSN (label) != 0)
881 /* Find the innermost pending block that contains the label.
882 (Check containment by comparing insn-uids.)
883 Then restore the outermost stack level within that block,
884 and do cleanups of all blocks contained in it. */
885 for (block = block_stack; block; block = block->next)
887 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
889 if (block->data.block.stack_level != 0)
890 stack_level = block->data.block.stack_level;
891 /* Execute the cleanups for blocks we are exiting. */
892 if (block->data.block.cleanups != 0)
894 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
895 do_pending_stack_adjust ();
901 /* Ensure stack adjust isn't done by emit_jump, as this
902 would clobber the stack pointer. This one should be
903 deleted as dead by flow. */
904 clear_pending_stack_adjust ();
905 do_pending_stack_adjust ();
906 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
909 if (body != 0 && DECL_TOO_LATE (body))
910 error ("jump to `%s' invalidly jumps into binding contour",
911 IDENTIFIER_POINTER (DECL_NAME (body)));
913 /* Label not yet defined: may need to put this goto
914 on the fixup list. */
915 else if (! expand_fixup (body, label, last_insn))
917 /* No fixup needed. Record that the label is the target
918 of at least one goto that has no fixup. */
920 TREE_ADDRESSABLE (body) = 1;
926 /* Generate if necessary a fixup for a goto
927 whose target label in tree structure (if any) is TREE_LABEL
928 and whose target in rtl is RTL_LABEL.
930 If LAST_INSN is nonzero, we pretend that the jump appears
931 after insn LAST_INSN instead of at the current point in the insn stream.
933 The fixup will be used later to insert insns just before the goto.
934 Those insns will restore the stack level as appropriate for the
935 target label, and will (in the case of C++) also invoke any object
936 destructors which have to be invoked when we exit the scopes which
937 are exited by the goto.
939 Value is nonzero if a fixup is made. */
942 expand_fixup (tree_label, rtl_label, last_insn)
947 struct nesting *block, *end_block;
949 /* See if we can recognize which block the label will be output in.
950 This is possible in some very common cases.
951 If we succeed, set END_BLOCK to that block.
952 Otherwise, set it to 0. */
955 && (rtl_label == cond_stack->data.cond.endif_label
956 || rtl_label == cond_stack->data.cond.next_label))
957 end_block = cond_stack;
958 /* If we are in a loop, recognize certain labels which
959 are likely targets. This reduces the number of fixups
960 we need to create. */
962 && (rtl_label == loop_stack->data.loop.start_label
963 || rtl_label == loop_stack->data.loop.end_label
964 || rtl_label == loop_stack->data.loop.continue_label))
965 end_block = loop_stack;
969 /* Now set END_BLOCK to the binding level to which we will return. */
973 struct nesting *next_block = end_block->all;
976 /* First see if the END_BLOCK is inside the innermost binding level.
977 If so, then no cleanups or stack levels are relevant. */
978 while (next_block && next_block != block)
979 next_block = next_block->all;
984 /* Otherwise, set END_BLOCK to the innermost binding level
985 which is outside the relevant control-structure nesting. */
986 next_block = block_stack->next;
987 for (block = block_stack; block != end_block; block = block->all)
988 if (block == next_block)
989 next_block = next_block->next;
990 end_block = next_block;
993 /* Does any containing block have a stack level or cleanups?
994 If not, no fixup is needed, and that is the normal case
995 (the only case, for standard C). */
996 for (block = block_stack; block != end_block; block = block->next)
997 if (block->data.block.stack_level != 0
998 || block->data.block.cleanups != 0)
1001 if (block != end_block)
1003 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1004 struct goto_fixup *fixup
1005 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1006 /* In case an old stack level is restored, make sure that comes
1007 after any pending stack adjust. */
1008 /* ?? If the fixup isn't to come at the present position,
1009 doing the stack adjust here isn't useful. Doing it with our
1010 settings at that location isn't useful either. Let's hope
1013 do_pending_stack_adjust ();
1014 fixup->target = tree_label;
1015 fixup->target_rtl = rtl_label;
1017 /* Create a BLOCK node and a corresponding matched set of
1018 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1019 this point. The notes will encapsulate any and all fixup
1020 code which we might later insert at this point in the insn
1021 stream. Also, the BLOCK node will be the parent (i.e. the
1022 `SUPERBLOCK') of any other BLOCK nodes which we might create
1023 later on when we are expanding the fixup code.
1025 Note that optimization passes (including expand_end_loop)
1026 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1027 as a placeholder. */
1030 register rtx original_before_jump
1031 = last_insn ? last_insn : get_last_insn ();
1036 block = make_node (BLOCK);
1037 TREE_USED (block) = 1;
1039 if (!cfun->x_whole_function_mode_p)
1040 insert_block (block);
1044 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1045 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1050 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1051 if (cfun->x_whole_function_mode_p)
1052 NOTE_BLOCK (start) = block;
1053 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1054 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1055 if (cfun->x_whole_function_mode_p)
1056 NOTE_BLOCK (end) = block;
1057 fixup->context = block;
1059 emit_insns_after (start, original_before_jump);
1062 fixup->block_start_count = current_block_start_count;
1063 fixup->stack_level = 0;
1064 fixup->cleanup_list_list
1065 = ((block->data.block.outer_cleanups
1066 || block->data.block.cleanups)
1067 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1068 block->data.block.outer_cleanups)
1070 fixup->next = goto_fixup_chain;
1071 goto_fixup_chain = fixup;
1079 /* Expand any needed fixups in the outputmost binding level of the
1080 function. FIRST_INSN is the first insn in the function. */
1083 expand_fixups (first_insn)
1086 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1089 /* When exiting a binding contour, process all pending gotos requiring fixups.
1090 THISBLOCK is the structure that describes the block being exited.
1091 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1092 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1093 FIRST_INSN is the insn that began this contour.
1095 Gotos that jump out of this contour must restore the
1096 stack level and do the cleanups before actually jumping.
1098 DONT_JUMP_IN nonzero means report error there is a jump into this
1099 contour from before the beginning of the contour.
1100 This is also done if STACK_LEVEL is nonzero. */
1103 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1104 struct nesting *thisblock;
1110 register struct goto_fixup *f, *prev;
1112 /* F is the fixup we are considering; PREV is the previous one. */
1113 /* We run this loop in two passes so that cleanups of exited blocks
1114 are run first, and blocks that are exited are marked so
1117 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1119 /* Test for a fixup that is inactive because it is already handled. */
1120 if (f->before_jump == 0)
1122 /* Delete inactive fixup from the chain, if that is easy to do. */
1124 prev->next = f->next;
1126 /* Has this fixup's target label been defined?
1127 If so, we can finalize it. */
1128 else if (PREV_INSN (f->target_rtl) != 0)
1130 register rtx cleanup_insns;
1132 /* If this fixup jumped into this contour from before the beginning
1133 of this contour, report an error. This code used to use
1134 the first non-label insn after f->target_rtl, but that's
1135 wrong since such can be added, by things like put_var_into_stack
1136 and have INSN_UIDs that are out of the range of the block. */
1137 /* ??? Bug: this does not detect jumping in through intermediate
1138 blocks that have stack levels or cleanups.
1139 It detects only a problem with the innermost block
1140 around the label. */
1142 && (dont_jump_in || stack_level || cleanup_list)
1143 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1144 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1145 && ! DECL_ERROR_ISSUED (f->target))
1147 error_with_decl (f->target,
1148 "label `%s' used before containing binding contour");
1149 /* Prevent multiple errors for one label. */
1150 DECL_ERROR_ISSUED (f->target) = 1;
1153 /* We will expand the cleanups into a sequence of their own and
1154 then later on we will attach this new sequence to the insn
1155 stream just ahead of the actual jump insn. */
1159 /* Temporarily restore the lexical context where we will
1160 logically be inserting the fixup code. We do this for the
1161 sake of getting the debugging information right. */
1164 set_block (f->context);
1166 /* Expand the cleanups for blocks this jump exits. */
1167 if (f->cleanup_list_list)
1170 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1171 /* Marked elements correspond to blocks that have been closed.
1172 Do their cleanups. */
1173 if (TREE_ADDRESSABLE (lists)
1174 && TREE_VALUE (lists) != 0)
1176 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1177 /* Pop any pushes done in the cleanups,
1178 in case function is about to return. */
1179 do_pending_stack_adjust ();
1183 /* Restore stack level for the biggest contour that this
1184 jump jumps out of. */
1186 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1188 /* Finish up the sequence containing the insns which implement the
1189 necessary cleanups, and then attach that whole sequence to the
1190 insn stream just ahead of the actual jump insn. Attaching it
1191 at that point insures that any cleanups which are in fact
1192 implicit C++ object destructions (which must be executed upon
1193 leaving the block) appear (to the debugger) to be taking place
1194 in an area of the generated code where the object(s) being
1195 destructed are still "in scope". */
1197 cleanup_insns = get_insns ();
1201 emit_insns_after (cleanup_insns, f->before_jump);
1208 /* For any still-undefined labels, do the cleanups for this block now.
1209 We must do this now since items in the cleanup list may go out
1210 of scope when the block ends. */
1211 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1212 if (f->before_jump != 0
1213 && PREV_INSN (f->target_rtl) == 0
1214 /* Label has still not appeared. If we are exiting a block with
1215 a stack level to restore, that started before the fixup,
1216 mark this stack level as needing restoration
1217 when the fixup is later finalized. */
1219 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1220 means the label is undefined. That's erroneous, but possible. */
1221 && (thisblock->data.block.block_start_count
1222 <= f->block_start_count))
1224 tree lists = f->cleanup_list_list;
1227 for (; lists; lists = TREE_CHAIN (lists))
1228 /* If the following elt. corresponds to our containing block
1229 then the elt. must be for this block. */
1230 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1234 set_block (f->context);
1235 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1236 do_pending_stack_adjust ();
1237 cleanup_insns = get_insns ();
1240 if (cleanup_insns != 0)
1242 = emit_insns_after (cleanup_insns, f->before_jump);
1244 f->cleanup_list_list = TREE_CHAIN (lists);
1248 f->stack_level = stack_level;
1252 /* Return the number of times character C occurs in string S. */
1254 n_occurrences (c, s)
1264 /* Generate RTL for an asm statement (explicit assembler code).
1265 BODY is a STRING_CST node containing the assembler code text,
1266 or an ADDR_EXPR containing a STRING_CST. */
1272 if (current_function_check_memory_usage)
1274 error ("`asm' cannot be used in function where memory usage is checked");
1278 if (TREE_CODE (body) == ADDR_EXPR)
1279 body = TREE_OPERAND (body, 0);
1281 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1282 TREE_STRING_POINTER (body)));
1286 /* Generate RTL for an asm statement with arguments.
1287 STRING is the instruction template.
1288 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1289 Each output or input has an expression in the TREE_VALUE and
1290 a constraint-string in the TREE_PURPOSE.
1291 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1292 that is clobbered by this insn.
1294 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1295 Some elements of OUTPUTS may be replaced with trees representing temporary
1296 values. The caller should copy those temporary values to the originally
1299 VOL nonzero means the insn is volatile; don't optimize it. */
1302 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1303 tree string, outputs, inputs, clobbers;
1308 rtvec argvec, constraints;
1310 int ninputs = list_length (inputs);
1311 int noutputs = list_length (outputs);
1316 /* Vector of RTX's of evaluated output operands. */
1317 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1318 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1319 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1320 enum machine_mode *inout_mode
1321 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1322 /* The insn we have emitted. */
1325 /* An ASM with no outputs needs to be treated as volatile, for now. */
1329 if (current_function_check_memory_usage)
1331 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1335 #ifdef MD_ASM_CLOBBERS
1336 /* Sometimes we wish to automatically clobber registers across an asm.
1337 Case in point is when the i386 backend moved from cc0 to a hard reg --
1338 maintaining source-level compatability means automatically clobbering
1339 the flags register. */
1340 MD_ASM_CLOBBERS (clobbers);
1343 if (current_function_check_memory_usage)
1345 error ("`asm' cannot be used in function where memory usage is checked");
1349 /* Count the number of meaningful clobbered registers, ignoring what
1350 we would ignore later. */
1352 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1354 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1356 i = decode_reg_name (regname);
1357 if (i >= 0 || i == -4)
1360 error ("unknown register name `%s' in `asm'", regname);
1365 /* Check that the number of alternatives is constant across all
1367 if (outputs || inputs)
1369 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1370 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1373 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1375 error ("too many alternatives in `asm'");
1382 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1384 if (n_occurrences (',', constraint) != nalternatives)
1386 error ("operand constraints for `asm' differ in number of alternatives");
1390 if (TREE_CHAIN (tmp))
1391 tmp = TREE_CHAIN (tmp);
1393 tmp = next, next = 0;
1397 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1399 tree val = TREE_VALUE (tail);
1400 tree type = TREE_TYPE (val);
1409 /* If there's an erroneous arg, emit no insn. */
1410 if (TREE_TYPE (val) == error_mark_node)
1413 /* Make sure constraint has `=' and does not have `+'. Also, see
1414 if it allows any register. Be liberal on the latter test, since
1415 the worst that happens if we get it wrong is we issue an error
1418 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1419 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1421 /* Allow the `=' or `+' to not be at the beginning of the string,
1422 since it wasn't explicitly documented that way, and there is a
1423 large body of code that puts it last. Swap the character to
1424 the front, so as not to uglify any place else. */
1428 if ((p = strchr (constraint, '=')) != NULL)
1430 if ((p = strchr (constraint, '+')) != NULL)
1433 error ("output operand constraint lacks `='");
1437 if (p != constraint)
1440 bcopy (constraint, constraint+1, p-constraint);
1443 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1446 is_inout = constraint[0] == '+';
1447 /* Replace '+' with '='. */
1448 constraint[0] = '=';
1449 /* Make sure we can specify the matching operand. */
1450 if (is_inout && i > 9)
1452 error ("output operand constraint %d contains `+'", i);
1456 for (j = 1; j < c_len; j++)
1457 switch (constraint[j])
1461 error ("operand constraint contains '+' or '=' at illegal position.");
1465 if (i + 1 == ninputs + noutputs)
1467 error ("`%%' constraint used with last operand");
1472 case '?': case '!': case '*': case '&':
1473 case 'E': case 'F': case 'G': case 'H':
1474 case 's': case 'i': case 'n':
1475 case 'I': case 'J': case 'K': case 'L': case 'M':
1476 case 'N': case 'O': case 'P': case ',':
1477 #ifdef EXTRA_CONSTRAINT
1478 case 'Q': case 'R': case 'S': case 'T': case 'U':
1482 case '0': case '1': case '2': case '3': case '4':
1483 case '5': case '6': case '7': case '8': case '9':
1484 error ("matching constraint not valid in output operand");
1487 case 'V': case 'm': case 'o':
1492 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1493 excepting those that expand_call created. So match memory
1509 /* If an output operand is not a decl or indirect ref and our constraint
1510 allows a register, make a temporary to act as an intermediate.
1511 Make the asm insn write into that, then our caller will copy it to
1512 the real output operand. Likewise for promoted variables. */
1514 real_output_rtx[i] = NULL_RTX;
1515 if ((TREE_CODE (val) == INDIRECT_REF
1518 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1519 && ! (GET_CODE (DECL_RTL (val)) == REG
1520 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1525 mark_addressable (TREE_VALUE (tail));
1528 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1529 EXPAND_MEMORY_USE_WO);
1531 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1532 error ("output number %d not directly addressable", i);
1533 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1535 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1536 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1538 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1543 output_rtx[i] = assign_temp (type, 0, 0, 1);
1544 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1549 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1550 inout_opnum[ninout++] = i;
1555 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1557 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1561 /* Make vectors for the expression-rtx and constraint strings. */
1563 argvec = rtvec_alloc (ninputs);
1564 constraints = rtvec_alloc (ninputs);
1566 body = gen_rtx_ASM_OPERANDS (VOIDmode, TREE_STRING_POINTER (string),
1567 empty_string, 0, argvec, constraints,
1570 MEM_VOLATILE_P (body) = vol;
1572 /* Eval the inputs and put them into ARGVEC.
1573 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1576 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1579 int allows_reg = 0, allows_mem = 0;
1580 char *constraint, *orig_constraint;
1584 /* If there's an erroneous arg, emit no insn,
1585 because the ASM_INPUT would get VOIDmode
1586 and that could cause a crash in reload. */
1587 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1590 /* ??? Can this happen, and does the error message make any sense? */
1591 if (TREE_PURPOSE (tail) == NULL_TREE)
1593 error ("hard register `%s' listed as input operand to `asm'",
1594 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1598 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1599 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1600 orig_constraint = constraint;
1602 /* Make sure constraint has neither `=', `+', nor '&'. */
1604 for (j = 0; j < c_len; j++)
1605 switch (constraint[j])
1607 case '+': case '=': case '&':
1608 if (constraint == orig_constraint)
1610 error ("input operand constraint contains `%c'",
1617 if (constraint == orig_constraint
1618 && i + 1 == ninputs - ninout)
1620 error ("`%%' constraint used with last operand");
1625 case 'V': case 'm': case 'o':
1630 case '?': case '!': case '*':
1631 case 'E': case 'F': case 'G': case 'H': case 'X':
1632 case 's': case 'i': case 'n':
1633 case 'I': case 'J': case 'K': case 'L': case 'M':
1634 case 'N': case 'O': case 'P': case ',':
1635 #ifdef EXTRA_CONSTRAINT
1636 case 'Q': case 'R': case 'S': case 'T': case 'U':
1640 /* Whether or not a numeric constraint allows a register is
1641 decided by the matching constraint, and so there is no need
1642 to do anything special with them. We must handle them in
1643 the default case, so that we don't unnecessarily force
1644 operands to memory. */
1645 case '0': case '1': case '2': case '3': case '4':
1646 case '5': case '6': case '7': case '8': case '9':
1647 if (constraint[j] >= '0' + noutputs)
1650 ("matching constraint references invalid operand number");
1654 /* Try and find the real constraint for this dup. */
1655 if ((j == 0 && c_len == 1)
1656 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1660 for (j = constraint[j] - '0'; j > 0; --j)
1663 c_len = strlen (TREE_STRING_POINTER (TREE_PURPOSE (o)));
1664 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1669 /* ... fall through ... */
1682 if (! allows_reg && allows_mem)
1683 mark_addressable (TREE_VALUE (tail));
1685 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1687 if (asm_operand_ok (op, constraint) <= 0)
1690 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1691 else if (!allows_mem)
1692 warning ("asm operand %d probably doesn't match constraints", i);
1693 else if (CONSTANT_P (op))
1694 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1696 else if (GET_CODE (op) == REG
1697 || GET_CODE (op) == SUBREG
1698 || GET_CODE (op) == CONCAT)
1700 tree type = TREE_TYPE (TREE_VALUE (tail));
1701 rtx memloc = assign_temp (type, 1, 1, 1);
1703 emit_move_insn (memloc, op);
1707 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1708 /* We won't recognize volatile memory as available a
1709 memory_operand at this point. Ignore it. */
1711 else if (queued_subexp_p (op))
1714 /* ??? Leave this only until we have experience with what
1715 happens in combine and elsewhere when constraints are
1717 warning ("asm operand %d probably doesn't match constraints", i);
1719 XVECEXP (body, 3, i) = op;
1721 XVECEXP (body, 4, i) /* constraints */
1722 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1727 /* Protect all the operands from the queue now that they have all been
1730 for (i = 0; i < ninputs - ninout; i++)
1731 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1733 for (i = 0; i < noutputs; i++)
1734 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1736 /* For in-out operands, copy output rtx to input rtx. */
1737 for (i = 0; i < ninout; i++)
1739 int j = inout_opnum[i];
1741 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1743 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1744 = gen_rtx_ASM_INPUT (inout_mode[i], digit_strings[j]);
1747 /* Now, for each output, construct an rtx
1748 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1749 ARGVEC CONSTRAINTS))
1750 If there is more than one, put them inside a PARALLEL. */
1752 if (noutputs == 1 && nclobbers == 0)
1754 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1755 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1758 else if (noutputs == 0 && nclobbers == 0)
1760 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1761 insn = emit_insn (body);
1772 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1774 /* For each output operand, store a SET. */
1775 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1777 XVECEXP (body, 0, i)
1778 = gen_rtx_SET (VOIDmode,
1780 gen_rtx_ASM_OPERANDS
1782 TREE_STRING_POINTER (string),
1783 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1784 i, argvec, constraints,
1787 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1790 /* If there are no outputs (but there are some clobbers)
1791 store the bare ASM_OPERANDS into the PARALLEL. */
1794 XVECEXP (body, 0, i++) = obody;
1796 /* Store (clobber REG) for each clobbered register specified. */
1798 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1800 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1801 int j = decode_reg_name (regname);
1805 if (j == -3) /* `cc', which is not a register */
1808 if (j == -4) /* `memory', don't cache memory across asm */
1810 XVECEXP (body, 0, i++)
1811 = gen_rtx_CLOBBER (VOIDmode,
1814 gen_rtx_SCRATCH (VOIDmode)));
1818 /* Ignore unknown register, error already signaled. */
1822 /* Use QImode since that's guaranteed to clobber just one reg. */
1823 XVECEXP (body, 0, i++)
1824 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1827 insn = emit_insn (body);
1830 /* For any outputs that needed reloading into registers, spill them
1831 back to where they belong. */
1832 for (i = 0; i < noutputs; ++i)
1833 if (real_output_rtx[i])
1834 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1839 /* Generate RTL to evaluate the expression EXP
1840 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1843 expand_expr_stmt (exp)
1846 /* If -W, warn about statements with no side effects,
1847 except for an explicit cast to void (e.g. for assert()), and
1848 except inside a ({...}) where they may be useful. */
1849 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1851 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1852 && !(TREE_CODE (exp) == CONVERT_EXPR
1853 && TREE_TYPE (exp) == void_type_node))
1854 warning_with_file_and_line (emit_filename, emit_lineno,
1855 "statement with no effect");
1856 else if (warn_unused)
1857 warn_if_unused_value (exp);
1860 /* If EXP is of function type and we are expanding statements for
1861 value, convert it to pointer-to-function. */
1862 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1863 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1865 last_expr_type = TREE_TYPE (exp);
1866 last_expr_value = expand_expr (exp,
1867 (expr_stmts_for_value
1868 ? NULL_RTX : const0_rtx),
1871 /* If all we do is reference a volatile value in memory,
1872 copy it to a register to be sure it is actually touched. */
1873 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1874 && TREE_THIS_VOLATILE (exp))
1876 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1878 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1879 copy_to_reg (last_expr_value);
1882 rtx lab = gen_label_rtx ();
1884 /* Compare the value with itself to reference it. */
1885 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1886 expand_expr (TYPE_SIZE (last_expr_type),
1887 NULL_RTX, VOIDmode, 0),
1889 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1895 /* If this expression is part of a ({...}) and is in memory, we may have
1896 to preserve temporaries. */
1897 preserve_temp_slots (last_expr_value);
1899 /* Free any temporaries used to evaluate this expression. Any temporary
1900 used as a result of this expression will already have been preserved
1907 /* Warn if EXP contains any computations whose results are not used.
1908 Return 1 if a warning is printed; 0 otherwise. */
1911 warn_if_unused_value (exp)
1914 if (TREE_USED (exp))
1917 switch (TREE_CODE (exp))
1919 case PREINCREMENT_EXPR:
1920 case POSTINCREMENT_EXPR:
1921 case PREDECREMENT_EXPR:
1922 case POSTDECREMENT_EXPR:
1927 case METHOD_CALL_EXPR:
1929 case TRY_CATCH_EXPR:
1930 case WITH_CLEANUP_EXPR:
1932 /* We don't warn about COND_EXPR because it may be a useful
1933 construct if either arm contains a side effect. */
1938 /* For a binding, warn if no side effect within it. */
1939 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1942 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1944 case TRUTH_ORIF_EXPR:
1945 case TRUTH_ANDIF_EXPR:
1946 /* In && or ||, warn if 2nd operand has no side effect. */
1947 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1950 if (TREE_NO_UNUSED_WARNING (exp))
1952 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1954 /* Let people do `(foo (), 0)' without a warning. */
1955 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1957 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1961 case NON_LVALUE_EXPR:
1962 /* Don't warn about values cast to void. */
1963 if (TREE_TYPE (exp) == void_type_node)
1965 /* Don't warn about conversions not explicit in the user's program. */
1966 if (TREE_NO_UNUSED_WARNING (exp))
1968 /* Assignment to a cast usually results in a cast of a modify.
1969 Don't complain about that. There can be an arbitrary number of
1970 casts before the modify, so we must loop until we find the first
1971 non-cast expression and then test to see if that is a modify. */
1973 tree tem = TREE_OPERAND (exp, 0);
1975 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1976 tem = TREE_OPERAND (tem, 0);
1978 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1979 || TREE_CODE (tem) == CALL_EXPR)
1985 /* Don't warn about automatic dereferencing of references, since
1986 the user cannot control it. */
1987 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1988 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1989 /* ... fall through ... */
1992 /* Referencing a volatile value is a side effect, so don't warn. */
1994 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1995 && TREE_THIS_VOLATILE (exp))
1998 warning_with_file_and_line (emit_filename, emit_lineno,
1999 "value computed is not used");
2004 /* Clear out the memory of the last expression evaluated. */
2012 /* Begin a statement which will return a value.
2013 Return the RTL_EXPR for this statement expr.
2014 The caller must save that value and pass it to expand_end_stmt_expr. */
2017 expand_start_stmt_expr ()
2022 /* Make the RTL_EXPR node temporary, not momentary,
2023 so that rtl_expr_chain doesn't become garbage. */
2024 momentary = suspend_momentary ();
2025 t = make_node (RTL_EXPR);
2026 resume_momentary (momentary);
2027 do_pending_stack_adjust ();
2028 start_sequence_for_rtl_expr (t);
2030 expr_stmts_for_value++;
2034 /* Restore the previous state at the end of a statement that returns a value.
2035 Returns a tree node representing the statement's value and the
2036 insns to compute the value.
2038 The nodes of that expression have been freed by now, so we cannot use them.
2039 But we don't want to do that anyway; the expression has already been
2040 evaluated and now we just want to use the value. So generate a RTL_EXPR
2041 with the proper type and RTL value.
2043 If the last substatement was not an expression,
2044 return something with type `void'. */
2047 expand_end_stmt_expr (t)
2052 if (last_expr_type == 0)
2054 last_expr_type = void_type_node;
2055 last_expr_value = const0_rtx;
2057 else if (last_expr_value == 0)
2058 /* There are some cases where this can happen, such as when the
2059 statement is void type. */
2060 last_expr_value = const0_rtx;
2061 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2062 /* Remove any possible QUEUED. */
2063 last_expr_value = protect_from_queue (last_expr_value, 0);
2067 TREE_TYPE (t) = last_expr_type;
2068 RTL_EXPR_RTL (t) = last_expr_value;
2069 RTL_EXPR_SEQUENCE (t) = get_insns ();
2071 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2075 /* Don't consider deleting this expr or containing exprs at tree level. */
2076 TREE_SIDE_EFFECTS (t) = 1;
2077 /* Propagate volatility of the actual RTL expr. */
2078 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2081 expr_stmts_for_value--;
2086 /* Generate RTL for the start of an if-then. COND is the expression
2087 whose truth should be tested.
2089 If EXITFLAG is nonzero, this conditional is visible to
2090 `exit_something'. */
2093 expand_start_cond (cond, exitflag)
2097 struct nesting *thiscond = ALLOC_NESTING ();
2099 /* Make an entry on cond_stack for the cond we are entering. */
2101 thiscond->next = cond_stack;
2102 thiscond->all = nesting_stack;
2103 thiscond->depth = ++nesting_depth;
2104 thiscond->data.cond.next_label = gen_label_rtx ();
2105 /* Before we encounter an `else', we don't need a separate exit label
2106 unless there are supposed to be exit statements
2107 to exit this conditional. */
2108 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2109 thiscond->data.cond.endif_label = thiscond->exit_label;
2110 cond_stack = thiscond;
2111 nesting_stack = thiscond;
2113 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2116 /* Generate RTL between then-clause and the elseif-clause
2117 of an if-then-elseif-.... */
2120 expand_start_elseif (cond)
2123 if (cond_stack->data.cond.endif_label == 0)
2124 cond_stack->data.cond.endif_label = gen_label_rtx ();
2125 emit_jump (cond_stack->data.cond.endif_label);
2126 emit_label (cond_stack->data.cond.next_label);
2127 cond_stack->data.cond.next_label = gen_label_rtx ();
2128 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2131 /* Generate RTL between the then-clause and the else-clause
2132 of an if-then-else. */
2135 expand_start_else ()
2137 if (cond_stack->data.cond.endif_label == 0)
2138 cond_stack->data.cond.endif_label = gen_label_rtx ();
2140 emit_jump (cond_stack->data.cond.endif_label);
2141 emit_label (cond_stack->data.cond.next_label);
2142 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2145 /* After calling expand_start_else, turn this "else" into an "else if"
2146 by providing another condition. */
2149 expand_elseif (cond)
2152 cond_stack->data.cond.next_label = gen_label_rtx ();
2153 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2156 /* Generate RTL for the end of an if-then.
2157 Pop the record for it off of cond_stack. */
2162 struct nesting *thiscond = cond_stack;
2164 do_pending_stack_adjust ();
2165 if (thiscond->data.cond.next_label)
2166 emit_label (thiscond->data.cond.next_label);
2167 if (thiscond->data.cond.endif_label)
2168 emit_label (thiscond->data.cond.endif_label);
2170 POPSTACK (cond_stack);
2176 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2177 loop should be exited by `exit_something'. This is a loop for which
2178 `expand_continue' will jump to the top of the loop.
2180 Make an entry on loop_stack to record the labels associated with
2184 expand_start_loop (exit_flag)
2187 register struct nesting *thisloop = ALLOC_NESTING ();
2189 /* Make an entry on loop_stack for the loop we are entering. */
2191 thisloop->next = loop_stack;
2192 thisloop->all = nesting_stack;
2193 thisloop->depth = ++nesting_depth;
2194 thisloop->data.loop.start_label = gen_label_rtx ();
2195 thisloop->data.loop.end_label = gen_label_rtx ();
2196 thisloop->data.loop.alt_end_label = 0;
2197 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2198 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2199 loop_stack = thisloop;
2200 nesting_stack = thisloop;
2202 do_pending_stack_adjust ();
2204 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2205 emit_label (thisloop->data.loop.start_label);
2210 /* Like expand_start_loop but for a loop where the continuation point
2211 (for expand_continue_loop) will be specified explicitly. */
2214 expand_start_loop_continue_elsewhere (exit_flag)
2217 struct nesting *thisloop = expand_start_loop (exit_flag);
2218 loop_stack->data.loop.continue_label = gen_label_rtx ();
2222 /* Specify the continuation point for a loop started with
2223 expand_start_loop_continue_elsewhere.
2224 Use this at the point in the code to which a continue statement
2228 expand_loop_continue_here ()
2230 do_pending_stack_adjust ();
2231 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2232 emit_label (loop_stack->data.loop.continue_label);
2235 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2236 Pop the block off of loop_stack. */
2241 rtx start_label = loop_stack->data.loop.start_label;
2242 rtx insn = get_last_insn ();
2243 int needs_end_jump = 1;
2245 /* Mark the continue-point at the top of the loop if none elsewhere. */
2246 if (start_label == loop_stack->data.loop.continue_label)
2247 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2249 do_pending_stack_adjust ();
2251 /* If optimizing, perhaps reorder the loop.
2252 First, try to use a condjump near the end.
2253 expand_exit_loop_if_false ends loops with unconditional jumps,
2256 if (test) goto label;
2258 goto loop_stack->data.loop.end_label
2262 If we find such a pattern, we can end the loop earlier. */
2265 && GET_CODE (insn) == CODE_LABEL
2266 && LABEL_NAME (insn) == NULL
2267 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2270 rtx jump = PREV_INSN (PREV_INSN (label));
2272 if (GET_CODE (jump) == JUMP_INSN
2273 && GET_CODE (PATTERN (jump)) == SET
2274 && SET_DEST (PATTERN (jump)) == pc_rtx
2275 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2276 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2277 == loop_stack->data.loop.end_label))
2281 /* The test might be complex and reference LABEL multiple times,
2282 like the loop in loop_iterations to set vtop. To handle this,
2284 insn = PREV_INSN (label);
2285 reorder_insns (label, label, start_label);
2287 for (prev = PREV_INSN (jump); ; prev = PREV_INSN (prev))
2289 /* We ignore line number notes, but if we see any other note,
2290 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2291 NOTE_INSN_LOOP_*, we disable this optimization. */
2292 if (GET_CODE (prev) == NOTE)
2294 if (NOTE_LINE_NUMBER (prev) < 0)
2298 if (GET_CODE (prev) == CODE_LABEL)
2300 if (GET_CODE (prev) == JUMP_INSN)
2302 if (GET_CODE (PATTERN (prev)) == SET
2303 && SET_DEST (PATTERN (prev)) == pc_rtx
2304 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2305 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2307 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2309 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2311 emit_note_after (NOTE_INSN_LOOP_END, prev);
2320 /* If the loop starts with a loop exit, roll that to the end where
2321 it will optimize together with the jump back.
2323 We look for the conditional branch to the exit, except that once
2324 we find such a branch, we don't look past 30 instructions.
2326 In more detail, if the loop presently looks like this (in pseudo-C):
2329 if (test) goto end_label;
2334 transform it to look like:
2340 if (test) goto end_label;
2341 goto newstart_label;
2344 Here, the `test' may actually consist of some reasonably complex
2345 code, terminating in a test. */
2350 ! (GET_CODE (insn) == JUMP_INSN
2351 && GET_CODE (PATTERN (insn)) == SET
2352 && SET_DEST (PATTERN (insn)) == pc_rtx
2353 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2357 rtx last_test_insn = NULL_RTX;
2359 /* Scan insns from the top of the loop looking for a qualified
2360 conditional exit. */
2361 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2362 insn = NEXT_INSN (insn))
2364 if (GET_CODE (insn) == NOTE)
2367 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2368 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2369 /* The code that actually moves the exit test will
2370 carefully leave BLOCK notes in their original
2371 location. That means, however, that we can't debug
2372 the exit test itself. So, we refuse to move code
2373 containing BLOCK notes at low optimization levels. */
2376 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2378 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2382 /* We've come to the end of an EH region, but
2383 never saw the beginning of that region. That
2384 means that an EH region begins before the top
2385 of the loop, and ends in the middle of it. The
2386 existence of such a situation violates a basic
2387 assumption in this code, since that would imply
2388 that even when EH_REGIONS is zero, we might
2389 move code out of an exception region. */
2393 /* We must not walk into a nested loop. */
2394 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2397 /* We already know this INSN is a NOTE, so there's no
2398 point in looking at it to see if it's a JUMP. */
2402 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2405 if (last_test_insn && num_insns > 30)
2409 /* We don't want to move a partial EH region. Consider:
2423 This isn't legal C++, but here's what it's supposed to
2424 mean: if cond() is true, stop looping. Otherwise,
2425 call bar, and keep looping. In addition, if cond
2426 throws an exception, catch it and keep looping. Such
2427 constructs are certainy legal in LISP.
2429 We should not move the `if (cond()) 0' test since then
2430 the EH-region for the try-block would be broken up.
2431 (In this case we would the EH_BEG note for the `try'
2432 and `if cond()' but not the call to bar() or the
2435 So we don't look for tests within an EH region. */
2438 if (GET_CODE (insn) == JUMP_INSN
2439 && GET_CODE (PATTERN (insn)) == SET
2440 && SET_DEST (PATTERN (insn)) == pc_rtx)
2442 /* This is indeed a jump. */
2443 rtx dest1 = NULL_RTX;
2444 rtx dest2 = NULL_RTX;
2445 rtx potential_last_test;
2446 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2448 /* A conditional jump. */
2449 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2450 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2451 potential_last_test = insn;
2455 /* An unconditional jump. */
2456 dest1 = SET_SRC (PATTERN (insn));
2457 /* Include the BARRIER after the JUMP. */
2458 potential_last_test = NEXT_INSN (insn);
2462 if (dest1 && GET_CODE (dest1) == LABEL_REF
2463 && ((XEXP (dest1, 0)
2464 == loop_stack->data.loop.alt_end_label)
2466 == loop_stack->data.loop.end_label)))
2468 last_test_insn = potential_last_test;
2472 /* If this was a conditional jump, there may be
2473 another label at which we should look. */
2480 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2482 /* We found one. Move everything from there up
2483 to the end of the loop, and add a jump into the loop
2484 to jump to there. */
2485 register rtx newstart_label = gen_label_rtx ();
2486 register rtx start_move = start_label;
2489 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2490 then we want to move this note also. */
2491 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2492 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2493 == NOTE_INSN_LOOP_CONT))
2494 start_move = PREV_INSN (start_move);
2496 emit_label_after (newstart_label, PREV_INSN (start_move));
2498 /* Actually move the insns. Start at the beginning, and
2499 keep copying insns until we've copied the
2501 for (insn = start_move; insn; insn = next_insn)
2503 /* Figure out which insn comes after this one. We have
2504 to do this before we move INSN. */
2505 if (insn == last_test_insn)
2506 /* We've moved all the insns. */
2507 next_insn = NULL_RTX;
2509 next_insn = NEXT_INSN (insn);
2511 if (GET_CODE (insn) == NOTE
2512 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2513 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2514 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2515 NOTE_INSN_BLOCK_ENDs because the correct generation
2516 of debugging information depends on these appearing
2517 in the same order in the RTL and in the tree
2518 structure, where they are represented as BLOCKs.
2519 So, we don't move block notes. Of course, moving
2520 the code inside the block is likely to make it
2521 impossible to debug the instructions in the exit
2522 test, but such is the price of optimization. */
2525 /* Move the INSN. */
2526 reorder_insns (insn, insn, get_last_insn ());
2529 emit_jump_insn_after (gen_jump (start_label),
2530 PREV_INSN (newstart_label));
2531 emit_barrier_after (PREV_INSN (newstart_label));
2532 start_label = newstart_label;
2538 emit_jump (start_label);
2539 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2541 emit_label (loop_stack->data.loop.end_label);
2543 POPSTACK (loop_stack);
2548 /* Generate a jump to the current loop's continue-point.
2549 This is usually the top of the loop, but may be specified
2550 explicitly elsewhere. If not currently inside a loop,
2551 return 0 and do nothing; caller will print an error message. */
2554 expand_continue_loop (whichloop)
2555 struct nesting *whichloop;
2559 whichloop = loop_stack;
2562 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2567 /* Generate a jump to exit the current loop. If not currently inside a loop,
2568 return 0 and do nothing; caller will print an error message. */
2571 expand_exit_loop (whichloop)
2572 struct nesting *whichloop;
2576 whichloop = loop_stack;
2579 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2583 /* Generate a conditional jump to exit the current loop if COND
2584 evaluates to zero. If not currently inside a loop,
2585 return 0 and do nothing; caller will print an error message. */
2588 expand_exit_loop_if_false (whichloop, cond)
2589 struct nesting *whichloop;
2592 rtx label = gen_label_rtx ();
2597 whichloop = loop_stack;
2600 /* In order to handle fixups, we actually create a conditional jump
2601 around a unconditional branch to exit the loop. If fixups are
2602 necessary, they go before the unconditional branch. */
2605 do_jump (cond, NULL_RTX, label);
2606 last_insn = get_last_insn ();
2607 if (GET_CODE (last_insn) == CODE_LABEL)
2608 whichloop->data.loop.alt_end_label = last_insn;
2609 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2616 /* Return nonzero if the loop nest is empty. Else return zero. */
2619 stmt_loop_nest_empty ()
2621 return (loop_stack == NULL);
2624 /* Return non-zero if we should preserve sub-expressions as separate
2625 pseudos. We never do so if we aren't optimizing. We always do so
2626 if -fexpensive-optimizations.
2628 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2629 the loop may still be a small one. */
2632 preserve_subexpressions_p ()
2636 if (flag_expensive_optimizations)
2639 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2642 insn = get_last_insn_anywhere ();
2645 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2646 < n_non_fixed_regs * 3));
2650 /* Generate a jump to exit the current loop, conditional, binding contour
2651 or case statement. Not all such constructs are visible to this function,
2652 only those started with EXIT_FLAG nonzero. Individual languages use
2653 the EXIT_FLAG parameter to control which kinds of constructs you can
2656 If not currently inside anything that can be exited,
2657 return 0 and do nothing; caller will print an error message. */
2660 expand_exit_something ()
2664 for (n = nesting_stack; n; n = n->all)
2665 if (n->exit_label != 0)
2667 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2674 /* Generate RTL to return from the current function, with no value.
2675 (That is, we do not do anything about returning any value.) */
2678 expand_null_return ()
2680 struct nesting *block = block_stack;
2681 rtx last_insn = get_last_insn ();
2683 /* If this function was declared to return a value, but we
2684 didn't, clobber the return registers so that they are not
2685 propogated live to the rest of the function. */
2686 clobber_return_register ();
2688 /* Does any pending block have cleanups? */
2689 while (block && block->data.block.cleanups == 0)
2690 block = block->next;
2692 /* If yes, use a goto to return, since that runs cleanups. */
2694 expand_null_return_1 (last_insn, block != 0);
2697 /* Generate RTL to return from the current function, with value VAL. */
2700 expand_value_return (val)
2703 struct nesting *block = block_stack;
2704 rtx last_insn = get_last_insn ();
2705 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2707 /* Copy the value to the return location
2708 unless it's already there. */
2710 if (return_reg != val)
2712 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2713 #ifdef PROMOTE_FUNCTION_RETURN
2714 int unsignedp = TREE_UNSIGNED (type);
2715 enum machine_mode old_mode
2716 = DECL_MODE (DECL_RESULT (current_function_decl));
2717 enum machine_mode mode
2718 = promote_mode (type, old_mode, &unsignedp, 1);
2720 if (mode != old_mode)
2721 val = convert_modes (mode, old_mode, val, unsignedp);
2723 if (GET_CODE (return_reg) == PARALLEL)
2724 emit_group_load (return_reg, val, int_size_in_bytes (type),
2725 TYPE_ALIGN (type) / BITS_PER_UNIT);
2727 emit_move_insn (return_reg, val);
2730 /* Does any pending block have cleanups? */
2732 while (block && block->data.block.cleanups == 0)
2733 block = block->next;
2735 /* If yes, use a goto to return, since that runs cleanups.
2736 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2738 expand_null_return_1 (last_insn, block != 0);
2741 /* Output a return with no value. If LAST_INSN is nonzero,
2742 pretend that the return takes place after LAST_INSN.
2743 If USE_GOTO is nonzero then don't use a return instruction;
2744 go to the return label instead. This causes any cleanups
2745 of pending blocks to be executed normally. */
2748 expand_null_return_1 (last_insn, use_goto)
2752 rtx end_label = cleanup_label ? cleanup_label : return_label;
2754 clear_pending_stack_adjust ();
2755 do_pending_stack_adjust ();
2758 /* PCC-struct return always uses an epilogue. */
2759 if (current_function_returns_pcc_struct || use_goto)
2762 end_label = return_label = gen_label_rtx ();
2763 expand_goto_internal (NULL_TREE, end_label, last_insn);
2767 /* Otherwise output a simple return-insn if one is available,
2768 unless it won't do the job. */
2770 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2772 emit_jump_insn (gen_return ());
2778 /* Otherwise jump to the epilogue. */
2779 expand_goto_internal (NULL_TREE, end_label, last_insn);
2782 /* Generate RTL to evaluate the expression RETVAL and return it
2783 from the current function. */
2786 expand_return (retval)
2789 /* If there are any cleanups to be performed, then they will
2790 be inserted following LAST_INSN. It is desirable
2791 that the last_insn, for such purposes, should be the
2792 last insn before computing the return value. Otherwise, cleanups
2793 which call functions can clobber the return value. */
2794 /* ??? rms: I think that is erroneous, because in C++ it would
2795 run destructors on variables that might be used in the subsequent
2796 computation of the return value. */
2798 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2799 register rtx val = 0;
2806 /* If function wants no value, give it none. */
2807 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2809 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2811 expand_null_return ();
2815 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2816 /* This is not sufficient. We also need to watch for cleanups of the
2817 expression we are about to expand. Unfortunately, we cannot know
2818 if it has cleanups until we expand it, and we want to change how we
2819 expand it depending upon if we need cleanups. We can't win. */
2821 cleanups = any_pending_cleanups (1);
2826 if (TREE_CODE (retval) == RESULT_DECL)
2827 retval_rhs = retval;
2828 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2829 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2830 retval_rhs = TREE_OPERAND (retval, 1);
2831 else if (TREE_TYPE (retval) == void_type_node)
2832 /* Recognize tail-recursive call to void function. */
2833 retval_rhs = retval;
2835 retval_rhs = NULL_TREE;
2837 /* Only use `last_insn' if there are cleanups which must be run. */
2838 if (cleanups || cleanup_label != 0)
2839 last_insn = get_last_insn ();
2841 /* Distribute return down conditional expr if either of the sides
2842 may involve tail recursion (see test below). This enhances the number
2843 of tail recursions we see. Don't do this always since it can produce
2844 sub-optimal code in some cases and we distribute assignments into
2845 conditional expressions when it would help. */
2847 if (optimize && retval_rhs != 0
2848 && frame_offset == 0
2849 && TREE_CODE (retval_rhs) == COND_EXPR
2850 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2851 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2853 rtx label = gen_label_rtx ();
2856 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2857 start_cleanup_deferral ();
2858 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2859 DECL_RESULT (current_function_decl),
2860 TREE_OPERAND (retval_rhs, 1));
2861 TREE_SIDE_EFFECTS (expr) = 1;
2862 expand_return (expr);
2865 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2866 DECL_RESULT (current_function_decl),
2867 TREE_OPERAND (retval_rhs, 2));
2868 TREE_SIDE_EFFECTS (expr) = 1;
2869 expand_return (expr);
2870 end_cleanup_deferral ();
2874 /* Attempt to optimize the call if it is tail recursive. */
2875 if (optimize_tail_recursion (retval_rhs, last_insn))
2879 /* This optimization is safe if there are local cleanups
2880 because expand_null_return takes care of them.
2881 ??? I think it should also be safe when there is a cleanup label,
2882 because expand_null_return takes care of them, too.
2883 Any reason why not? */
2884 if (HAVE_return && cleanup_label == 0
2885 && ! current_function_returns_pcc_struct
2886 && BRANCH_COST <= 1)
2888 /* If this is return x == y; then generate
2889 if (x == y) return 1; else return 0;
2890 if we can do it with explicit return insns and branches are cheap,
2891 but not if we have the corresponding scc insn. */
2894 switch (TREE_CODE (retval_rhs))
2920 case TRUTH_ANDIF_EXPR:
2921 case TRUTH_ORIF_EXPR:
2922 case TRUTH_AND_EXPR:
2924 case TRUTH_NOT_EXPR:
2925 case TRUTH_XOR_EXPR:
2928 op0 = gen_label_rtx ();
2929 jumpifnot (retval_rhs, op0);
2930 expand_value_return (const1_rtx);
2932 expand_value_return (const0_rtx);
2941 #endif /* HAVE_return */
2943 /* If the result is an aggregate that is being returned in one (or more)
2944 registers, load the registers here. The compiler currently can't handle
2945 copying a BLKmode value into registers. We could put this code in a
2946 more general area (for use by everyone instead of just function
2947 call/return), but until this feature is generally usable it is kept here
2948 (and in expand_call). The value must go into a pseudo in case there
2949 are cleanups that will clobber the real return register. */
2952 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2953 && GET_CODE (result_rtl) == REG)
2956 unsigned HOST_WIDE_INT bitpos, xbitpos;
2957 unsigned HOST_WIDE_INT big_endian_correction = 0;
2958 unsigned HOST_WIDE_INT bytes
2959 = int_size_in_bytes (TREE_TYPE (retval_rhs));
2960 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2961 unsigned int bitsize
2962 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
2963 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2964 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2965 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2966 enum machine_mode tmpmode, result_reg_mode;
2968 /* Structures whose size is not a multiple of a word are aligned
2969 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2970 machine, this means we must skip the empty high order bytes when
2971 calculating the bit offset. */
2972 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2973 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2976 /* Copy the structure BITSIZE bits at a time. */
2977 for (bitpos = 0, xbitpos = big_endian_correction;
2978 bitpos < bytes * BITS_PER_UNIT;
2979 bitpos += bitsize, xbitpos += bitsize)
2981 /* We need a new destination pseudo each time xbitpos is
2982 on a word boundary and when xbitpos == big_endian_correction
2983 (the first time through). */
2984 if (xbitpos % BITS_PER_WORD == 0
2985 || xbitpos == big_endian_correction)
2987 /* Generate an appropriate register. */
2988 dst = gen_reg_rtx (word_mode);
2989 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2991 /* Clobber the destination before we move anything into it. */
2992 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2995 /* We need a new source operand each time bitpos is on a word
2997 if (bitpos % BITS_PER_WORD == 0)
2998 src = operand_subword_force (result_val,
2999 bitpos / BITS_PER_WORD,
3002 /* Use bitpos for the source extraction (left justified) and
3003 xbitpos for the destination store (right justified). */
3004 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3005 extract_bit_field (src, bitsize,
3006 bitpos % BITS_PER_WORD, 1,
3007 NULL_RTX, word_mode,
3009 bitsize / BITS_PER_UNIT,
3011 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
3014 /* Find the smallest integer mode large enough to hold the
3015 entire structure and use that mode instead of BLKmode
3016 on the USE insn for the return register. */
3017 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
3018 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3019 tmpmode != VOIDmode;
3020 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3022 /* Have we found a large enough mode? */
3023 if (GET_MODE_SIZE (tmpmode) >= bytes)
3027 /* No suitable mode found. */
3028 if (tmpmode == VOIDmode)
3031 PUT_MODE (result_rtl, tmpmode);
3033 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3034 result_reg_mode = word_mode;
3036 result_reg_mode = tmpmode;
3037 result_reg = gen_reg_rtx (result_reg_mode);
3040 for (i = 0; i < n_regs; i++)
3041 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3044 if (tmpmode != result_reg_mode)
3045 result_reg = gen_lowpart (tmpmode, result_reg);
3047 expand_value_return (result_reg);
3051 && TREE_TYPE (retval_rhs) != void_type_node
3052 && (GET_CODE (result_rtl) == REG
3053 || (GET_CODE (result_rtl) == PARALLEL)))
3055 /* Calculate the return value into a temporary (usually a pseudo
3057 val = assign_temp (TREE_TYPE (DECL_RESULT (current_function_decl)),
3059 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3060 val = force_not_mem (val);
3062 /* Return the calculated value, doing cleanups first. */
3063 expand_value_return (val);
3067 /* No cleanups or no hard reg used;
3068 calculate value into hard return reg. */
3069 expand_expr (retval, const0_rtx, VOIDmode, 0);
3071 expand_value_return (result_rtl);
3075 /* Return 1 if the end of the generated RTX is not a barrier.
3076 This means code already compiled can drop through. */
3079 drop_through_at_end_p ()
3081 rtx insn = get_last_insn ();
3082 while (insn && GET_CODE (insn) == NOTE)
3083 insn = PREV_INSN (insn);
3084 return insn && GET_CODE (insn) != BARRIER;
3087 /* Test CALL_EXPR to determine if it is a potential tail recursion call
3088 and emit code to optimize the tail recursion. LAST_INSN indicates where
3089 to place the jump to the tail recursion label. Return TRUE if the
3090 call was optimized into a goto.
3092 This is only used by expand_return, but expand_call is expected to
3096 optimize_tail_recursion (call_expr, last_insn)
3100 /* For tail-recursive call to current function,
3101 just jump back to the beginning.
3102 It's unsafe if any auto variable in this function
3103 has its address taken; for simplicity,
3104 require stack frame to be empty. */
3105 if (optimize && call_expr != 0
3106 && frame_offset == 0
3107 && TREE_CODE (call_expr) == CALL_EXPR
3108 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
3109 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
3110 /* Finish checking validity, and if valid emit code
3111 to set the argument variables for the new call. */
3112 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
3113 DECL_ARGUMENTS (current_function_decl)))
3115 if (tail_recursion_label == 0)
3117 tail_recursion_label = gen_label_rtx ();
3118 emit_label_after (tail_recursion_label,
3119 tail_recursion_reentry);
3122 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3130 /* Emit code to alter this function's formal parms for a tail-recursive call.
3131 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3132 FORMALS is the chain of decls of formals.
3133 Return 1 if this can be done;
3134 otherwise return 0 and do not emit any code. */
3137 tail_recursion_args (actuals, formals)
3138 tree actuals, formals;
3140 register tree a = actuals, f = formals;
3142 register rtx *argvec;
3144 /* Check that number and types of actuals are compatible
3145 with the formals. This is not always true in valid C code.
3146 Also check that no formal needs to be addressable
3147 and that all formals are scalars. */
3149 /* Also count the args. */
3151 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3153 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3154 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3156 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3159 if (a != 0 || f != 0)
3162 /* Compute all the actuals. */
3164 argvec = (rtx *) alloca (i * sizeof (rtx));
3166 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3167 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3169 /* Find which actual values refer to current values of previous formals.
3170 Copy each of them now, before any formal is changed. */
3172 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3176 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3177 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3178 { copy = 1; break; }
3180 argvec[i] = copy_to_reg (argvec[i]);
3183 /* Store the values of the actuals into the formals. */
3185 for (f = formals, a = actuals, i = 0; f;
3186 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3188 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3189 emit_move_insn (DECL_RTL (f), argvec[i]);
3191 convert_move (DECL_RTL (f), argvec[i],
3192 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3199 /* Generate the RTL code for entering a binding contour.
3200 The variables are declared one by one, by calls to `expand_decl'.
3202 FLAGS is a bitwise or of the following flags:
3204 1 - Nonzero if this construct should be visible to
3207 2 - Nonzero if this contour does not require a
3208 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3209 language-independent code should set this flag because they
3210 will not create corresponding BLOCK nodes. (There should be
3211 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3212 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3213 when expand_end_bindings is called.
3215 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3216 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3220 expand_start_bindings_and_block (flags, block)
3224 struct nesting *thisblock = ALLOC_NESTING ();
3226 int exit_flag = ((flags & 1) != 0);
3227 int block_flag = ((flags & 2) == 0);
3229 /* If a BLOCK is supplied, then the caller should be requesting a
3230 NOTE_INSN_BLOCK_BEG note. */
3231 if (!block_flag && block)
3234 /* Create a note to mark the beginning of the block. */
3237 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3238 NOTE_BLOCK (note) = block;
3241 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3243 /* Make an entry on block_stack for the block we are entering. */
3245 thisblock->next = block_stack;
3246 thisblock->all = nesting_stack;
3247 thisblock->depth = ++nesting_depth;
3248 thisblock->data.block.stack_level = 0;
3249 thisblock->data.block.cleanups = 0;
3250 thisblock->data.block.n_function_calls = 0;
3251 thisblock->data.block.exception_region = 0;
3252 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3254 thisblock->data.block.conditional_code = 0;
3255 thisblock->data.block.last_unconditional_cleanup = note;
3256 /* When we insert instructions after the last unconditional cleanup,
3257 we don't adjust last_insn. That means that a later add_insn will
3258 clobber the instructions we've just added. The easiest way to
3259 fix this is to just insert another instruction here, so that the
3260 instructions inserted after the last unconditional cleanup are
3261 never the last instruction. */
3262 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3263 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3266 && !(block_stack->data.block.cleanups == NULL_TREE
3267 && block_stack->data.block.outer_cleanups == NULL_TREE))
3268 thisblock->data.block.outer_cleanups
3269 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3270 block_stack->data.block.outer_cleanups);
3272 thisblock->data.block.outer_cleanups = 0;
3273 thisblock->data.block.label_chain = 0;
3274 thisblock->data.block.innermost_stack_block = stack_block_stack;
3275 thisblock->data.block.first_insn = note;
3276 thisblock->data.block.block_start_count = ++current_block_start_count;
3277 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3278 block_stack = thisblock;
3279 nesting_stack = thisblock;
3281 /* Make a new level for allocating stack slots. */
3285 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3286 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3287 expand_expr are made. After we end the region, we know that all
3288 space for all temporaries that were created by TARGET_EXPRs will be
3289 destroyed and their space freed for reuse. */
3292 expand_start_target_temps ()
3294 /* This is so that even if the result is preserved, the space
3295 allocated will be freed, as we know that it is no longer in use. */
3298 /* Start a new binding layer that will keep track of all cleanup
3299 actions to be performed. */
3300 expand_start_bindings (2);
3302 target_temp_slot_level = temp_slot_level;
3306 expand_end_target_temps ()
3308 expand_end_bindings (NULL_TREE, 0, 0);
3310 /* This is so that even if the result is preserved, the space
3311 allocated will be freed, as we know that it is no longer in use. */
3315 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3316 in question represents the outermost pair of curly braces (i.e. the "body
3317 block") of a function or method.
3319 For any BLOCK node representing a "body block" of a function or method, the
3320 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3321 represents the outermost (function) scope for the function or method (i.e.
3322 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3323 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3326 is_body_block (stmt)
3329 if (TREE_CODE (stmt) == BLOCK)
3331 tree parent = BLOCK_SUPERCONTEXT (stmt);
3333 if (parent && TREE_CODE (parent) == BLOCK)
3335 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3337 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3345 /* Mark top block of block_stack as an implicit binding for an
3346 exception region. This is used to prevent infinite recursion when
3347 ending a binding with expand_end_bindings. It is only ever called
3348 by expand_eh_region_start, as that it the only way to create a
3349 block stack for a exception region. */
3352 mark_block_as_eh_region ()
3354 block_stack->data.block.exception_region = 1;
3355 if (block_stack->next
3356 && block_stack->next->data.block.conditional_code)
3358 block_stack->data.block.conditional_code
3359 = block_stack->next->data.block.conditional_code;
3360 block_stack->data.block.last_unconditional_cleanup
3361 = block_stack->next->data.block.last_unconditional_cleanup;
3362 block_stack->data.block.cleanup_ptr
3363 = block_stack->next->data.block.cleanup_ptr;
3367 /* True if we are currently emitting insns in an area of output code
3368 that is controlled by a conditional expression. This is used by
3369 the cleanup handling code to generate conditional cleanup actions. */
3372 conditional_context ()
3374 return block_stack && block_stack->data.block.conditional_code;
3377 /* Mark top block of block_stack as not for an implicit binding for an
3378 exception region. This is only ever done by expand_eh_region_end
3379 to let expand_end_bindings know that it is being called explicitly
3380 to end the binding layer for just the binding layer associated with
3381 the exception region, otherwise expand_end_bindings would try and
3382 end all implicit binding layers for exceptions regions, and then
3383 one normal binding layer. */
3386 mark_block_as_not_eh_region ()
3388 block_stack->data.block.exception_region = 0;
3391 /* True if the top block of block_stack was marked as for an exception
3392 region by mark_block_as_eh_region. */
3397 return cfun && block_stack && block_stack->data.block.exception_region;
3400 /* Emit a handler label for a nonlocal goto handler.
3401 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3404 expand_nl_handler_label (slot, before_insn)
3405 rtx slot, before_insn;
3408 rtx handler_label = gen_label_rtx ();
3410 /* Don't let jump_optimize delete the handler. */
3411 LABEL_PRESERVE_P (handler_label) = 1;
3414 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3415 insns = get_insns ();
3417 emit_insns_before (insns, before_insn);
3419 emit_label (handler_label);
3421 return handler_label;
3424 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3427 expand_nl_goto_receiver ()
3429 #ifdef HAVE_nonlocal_goto
3430 if (! HAVE_nonlocal_goto)
3432 /* First adjust our frame pointer to its actual value. It was
3433 previously set to the start of the virtual area corresponding to
3434 the stacked variables when we branched here and now needs to be
3435 adjusted to the actual hardware fp value.
3437 Assignments are to virtual registers are converted by
3438 instantiate_virtual_regs into the corresponding assignment
3439 to the underlying register (fp in this case) that makes
3440 the original assignment true.
3441 So the following insn will actually be
3442 decrementing fp by STARTING_FRAME_OFFSET. */
3443 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3445 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3446 if (fixed_regs[ARG_POINTER_REGNUM])
3448 #ifdef ELIMINABLE_REGS
3449 /* If the argument pointer can be eliminated in favor of the
3450 frame pointer, we don't need to restore it. We assume here
3451 that if such an elimination is present, it can always be used.
3452 This is the case on all known machines; if we don't make this
3453 assumption, we do unnecessary saving on many machines. */
3454 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3457 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3458 if (elim_regs[i].from == ARG_POINTER_REGNUM
3459 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3462 if (i == sizeof elim_regs / sizeof elim_regs [0])
3465 /* Now restore our arg pointer from the address at which it
3466 was saved in our stack frame.
3467 If there hasn't be space allocated for it yet, make
3469 if (arg_pointer_save_area == 0)
3470 arg_pointer_save_area
3471 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3472 emit_move_insn (virtual_incoming_args_rtx,
3473 /* We need a pseudo here, or else
3474 instantiate_virtual_regs_1 complains. */
3475 copy_to_reg (arg_pointer_save_area));
3480 #ifdef HAVE_nonlocal_goto_receiver
3481 if (HAVE_nonlocal_goto_receiver)
3482 emit_insn (gen_nonlocal_goto_receiver ());
3486 /* Make handlers for nonlocal gotos taking place in the function calls in
3490 expand_nl_goto_receivers (thisblock)
3491 struct nesting *thisblock;
3494 rtx afterward = gen_label_rtx ();
3499 /* Record the handler address in the stack slot for that purpose,
3500 during this block, saving and restoring the outer value. */
3501 if (thisblock->next != 0)
3502 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3504 rtx save_receiver = gen_reg_rtx (Pmode);
3505 emit_move_insn (XEXP (slot, 0), save_receiver);
3508 emit_move_insn (save_receiver, XEXP (slot, 0));
3509 insns = get_insns ();
3511 emit_insns_before (insns, thisblock->data.block.first_insn);
3514 /* Jump around the handlers; they run only when specially invoked. */
3515 emit_jump (afterward);
3517 /* Make a separate handler for each label. */
3518 link = nonlocal_labels;
3519 slot = nonlocal_goto_handler_slots;
3520 label_list = NULL_RTX;
3521 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3522 /* Skip any labels we shouldn't be able to jump to from here,
3523 we generate one special handler for all of them below which just calls
3525 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3528 lab = expand_nl_handler_label (XEXP (slot, 0),
3529 thisblock->data.block.first_insn);
3530 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3532 expand_nl_goto_receiver ();
3534 /* Jump to the "real" nonlocal label. */
3535 expand_goto (TREE_VALUE (link));
3538 /* A second pass over all nonlocal labels; this time we handle those
3539 we should not be able to jump to at this point. */
3540 link = nonlocal_labels;
3541 slot = nonlocal_goto_handler_slots;
3543 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3544 if (DECL_TOO_LATE (TREE_VALUE (link)))
3547 lab = expand_nl_handler_label (XEXP (slot, 0),
3548 thisblock->data.block.first_insn);
3549 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3555 expand_nl_goto_receiver ();
3556 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3561 nonlocal_goto_handler_labels = label_list;
3562 emit_label (afterward);
3565 /* Warn about any unused VARS (which may contain nodes other than
3566 VAR_DECLs, but such nodes are ignored). The nodes are connected
3567 via the TREE_CHAIN field. */
3570 warn_about_unused_variables (vars)
3576 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3577 if (TREE_CODE (decl) == VAR_DECL
3578 && ! TREE_USED (decl)
3579 && ! DECL_IN_SYSTEM_HEADER (decl)
3580 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3581 warning_with_decl (decl, "unused variable `%s'");
3584 /* Generate RTL code to terminate a binding contour.
3586 VARS is the chain of VAR_DECL nodes for the variables bound in this
3587 contour. There may actually be other nodes in this chain, but any
3588 nodes other than VAR_DECLS are ignored.
3590 MARK_ENDS is nonzero if we should put a note at the beginning
3591 and end of this binding contour.
3593 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3594 (That is true automatically if the contour has a saved stack level.) */
3597 expand_end_bindings (vars, mark_ends, dont_jump_in)
3602 register struct nesting *thisblock;
3604 while (block_stack->data.block.exception_region)
3606 /* Because we don't need or want a new temporary level and
3607 because we didn't create one in expand_eh_region_start,
3608 create a fake one now to avoid removing one in
3609 expand_end_bindings. */
3612 block_stack->data.block.exception_region = 0;
3614 expand_end_bindings (NULL_TREE, 0, 0);
3617 /* Since expand_eh_region_start does an expand_start_bindings, we
3618 have to first end all the bindings that were created by
3619 expand_eh_region_start. */
3621 thisblock = block_stack;
3623 /* If any of the variables in this scope were not used, warn the
3625 warn_about_unused_variables (vars);
3627 if (thisblock->exit_label)
3629 do_pending_stack_adjust ();
3630 emit_label (thisblock->exit_label);
3633 /* If necessary, make handlers for nonlocal gotos taking
3634 place in the function calls in this block. */
3635 if (function_call_count != thisblock->data.block.n_function_calls
3637 /* Make handler for outermost block
3638 if there were any nonlocal gotos to this function. */
3639 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3640 /* Make handler for inner block if it has something
3641 special to do when you jump out of it. */
3642 : (thisblock->data.block.cleanups != 0
3643 || thisblock->data.block.stack_level != 0)))
3644 expand_nl_goto_receivers (thisblock);
3646 /* Don't allow jumping into a block that has a stack level.
3647 Cleanups are allowed, though. */
3649 || thisblock->data.block.stack_level != 0)
3651 struct label_chain *chain;
3653 /* Any labels in this block are no longer valid to go to.
3654 Mark them to cause an error message. */
3655 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3657 DECL_TOO_LATE (chain->label) = 1;
3658 /* If any goto without a fixup came to this label,
3659 that must be an error, because gotos without fixups
3660 come from outside all saved stack-levels. */
3661 if (TREE_ADDRESSABLE (chain->label))
3662 error_with_decl (chain->label,
3663 "label `%s' used before containing binding contour");
3667 /* Restore stack level in effect before the block
3668 (only if variable-size objects allocated). */
3669 /* Perform any cleanups associated with the block. */
3671 if (thisblock->data.block.stack_level != 0
3672 || thisblock->data.block.cleanups != 0)
3674 /* Only clean up here if this point can actually be reached. */
3675 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3677 /* Don't let cleanups affect ({...}) constructs. */
3678 int old_expr_stmts_for_value = expr_stmts_for_value;
3679 rtx old_last_expr_value = last_expr_value;
3680 tree old_last_expr_type = last_expr_type;
3681 expr_stmts_for_value = 0;
3683 /* Do the cleanups. */
3684 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3686 do_pending_stack_adjust ();
3688 expr_stmts_for_value = old_expr_stmts_for_value;
3689 last_expr_value = old_last_expr_value;
3690 last_expr_type = old_last_expr_type;
3692 /* Restore the stack level. */
3694 if (reachable && thisblock->data.block.stack_level != 0)
3696 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3697 thisblock->data.block.stack_level, NULL_RTX);
3698 if (nonlocal_goto_handler_slots != 0)
3699 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3703 /* Any gotos out of this block must also do these things.
3704 Also report any gotos with fixups that came to labels in this
3706 fixup_gotos (thisblock,
3707 thisblock->data.block.stack_level,
3708 thisblock->data.block.cleanups,
3709 thisblock->data.block.first_insn,
3713 /* Mark the beginning and end of the scope if requested.
3714 We do this now, after running cleanups on the variables
3715 just going out of scope, so they are in scope for their cleanups. */
3719 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3720 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3723 /* Get rid of the beginning-mark if we don't make an end-mark. */
3724 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3726 /* Restore the temporary level of TARGET_EXPRs. */
3727 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3729 /* Restore block_stack level for containing block. */
3731 stack_block_stack = thisblock->data.block.innermost_stack_block;
3732 POPSTACK (block_stack);
3734 /* Pop the stack slot nesting and free any slots at this level. */
3738 /* Generate RTL for the automatic variable declaration DECL.
3739 (Other kinds of declarations are simply ignored if seen here.) */
3745 struct nesting *thisblock;
3748 type = TREE_TYPE (decl);
3750 /* Only automatic variables need any expansion done.
3751 Static and external variables, and external functions,
3752 will be handled by `assemble_variable' (called from finish_decl).
3753 TYPE_DECL and CONST_DECL require nothing.
3754 PARM_DECLs are handled in `assign_parms'. */
3756 if (TREE_CODE (decl) != VAR_DECL)
3758 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3761 thisblock = block_stack;
3763 /* Create the RTL representation for the variable. */
3765 if (type == error_mark_node)
3766 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3767 else if (DECL_SIZE (decl) == 0)
3768 /* Variable with incomplete type. */
3770 if (DECL_INITIAL (decl) == 0)
3771 /* Error message was already done; now avoid a crash. */
3772 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3774 /* An initializer is going to decide the size of this array.
3775 Until we know the size, represent its address with a reg. */
3776 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3777 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3779 else if (DECL_MODE (decl) != BLKmode
3780 /* If -ffloat-store, don't put explicit float vars
3782 && !(flag_float_store
3783 && TREE_CODE (type) == REAL_TYPE)
3784 && ! TREE_THIS_VOLATILE (decl)
3785 && ! TREE_ADDRESSABLE (decl)
3786 && (DECL_REGISTER (decl) || optimize)
3787 /* if -fcheck-memory-usage, check all variables. */
3788 && ! current_function_check_memory_usage)
3790 /* Automatic variable that can go in a register. */
3791 int unsignedp = TREE_UNSIGNED (type);
3792 enum machine_mode reg_mode
3793 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3795 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3796 mark_user_reg (DECL_RTL (decl));
3798 if (POINTER_TYPE_P (type))
3799 mark_reg_pointer (DECL_RTL (decl),
3800 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3804 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3805 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3806 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3807 STACK_CHECK_MAX_VAR_SIZE)))
3809 /* Variable of fixed size that goes on the stack. */
3813 /* If we previously made RTL for this decl, it must be an array
3814 whose size was determined by the initializer.
3815 The old address was a register; set that register now
3816 to the proper address. */
3817 if (DECL_RTL (decl) != 0)
3819 if (GET_CODE (DECL_RTL (decl)) != MEM
3820 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3822 oldaddr = XEXP (DECL_RTL (decl), 0);
3825 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3826 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3827 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3829 /* Set alignment we actually gave this decl. */
3830 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3831 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3835 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3836 if (addr != oldaddr)
3837 emit_move_insn (oldaddr, addr);
3840 /* If this is a memory ref that contains aggregate components,
3841 mark it as such for cse and loop optimize. */
3842 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3843 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3845 /* If this is in memory because of -ffloat-store,
3846 set the volatile bit, to prevent optimizations from
3847 undoing the effects. */
3848 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3849 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3852 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3855 /* Dynamic-size object: must push space on the stack. */
3859 /* Record the stack pointer on entry to block, if have
3860 not already done so. */
3861 if (thisblock->data.block.stack_level == 0)
3863 do_pending_stack_adjust ();
3864 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3865 &thisblock->data.block.stack_level,
3866 thisblock->data.block.first_insn);
3867 stack_block_stack = thisblock;
3870 /* In function-at-a-time mode, variable_size doesn't expand this,
3872 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3873 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3874 const0_rtx, VOIDmode, 0);
3876 /* Compute the variable's size, in bytes. */
3877 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3880 /* Allocate space on the stack for the variable. Note that
3881 DECL_ALIGN says how the variable is to be aligned and we
3882 cannot use it to conclude anything about the alignment of
3884 address = allocate_dynamic_stack_space (size, NULL_RTX,
3885 TYPE_ALIGN (TREE_TYPE (decl)));
3887 /* Reference the variable indirect through that rtx. */
3888 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3890 /* If this is a memory ref that contains aggregate components,
3891 mark it as such for cse and loop optimize. */
3892 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3893 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3895 /* Indicate the alignment we actually gave this variable. */
3896 #ifdef STACK_BOUNDARY
3897 DECL_ALIGN (decl) = STACK_BOUNDARY;
3899 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3903 if (TREE_THIS_VOLATILE (decl))
3904 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3906 if (TREE_READONLY (decl))
3907 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3910 /* Emit code to perform the initialization of a declaration DECL. */
3913 expand_decl_init (decl)
3916 int was_used = TREE_USED (decl);
3918 /* If this is a CONST_DECL, we don't have to generate any code, but
3919 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3920 to be set while in the obstack containing the constant. If we don't
3921 do this, we can lose if we have functions nested three deep and the middle
3922 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3923 the innermost function is the first to expand that STRING_CST. */
3924 if (TREE_CODE (decl) == CONST_DECL)
3926 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3927 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3928 EXPAND_INITIALIZER);
3932 if (TREE_STATIC (decl))
3935 /* Compute and store the initial value now. */
3937 if (DECL_INITIAL (decl) == error_mark_node)
3939 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3941 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3942 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3943 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3947 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3949 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3950 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3954 /* Don't let the initialization count as "using" the variable. */
3955 TREE_USED (decl) = was_used;
3957 /* Free any temporaries we made while initializing the decl. */
3958 preserve_temp_slots (NULL_RTX);
3962 /* CLEANUP is an expression to be executed at exit from this binding contour;
3963 for example, in C++, it might call the destructor for this variable.
3965 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3966 CLEANUP multiple times, and have the correct semantics. This
3967 happens in exception handling, for gotos, returns, breaks that
3968 leave the current scope.
3970 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3971 that is not associated with any particular variable. */
3974 expand_decl_cleanup (decl, cleanup)
3977 struct nesting *thisblock;
3979 /* Error if we are not in any block. */
3980 if (cfun == 0 || block_stack == 0)
3983 thisblock = block_stack;
3985 /* Record the cleanup if there is one. */
3991 tree *cleanups = &thisblock->data.block.cleanups;
3992 int cond_context = conditional_context ();
3996 rtx flag = gen_reg_rtx (word_mode);
4001 emit_move_insn (flag, const0_rtx);
4002 set_flag_0 = get_insns ();
4005 thisblock->data.block.last_unconditional_cleanup
4006 = emit_insns_after (set_flag_0,
4007 thisblock->data.block.last_unconditional_cleanup);
4009 emit_move_insn (flag, const1_rtx);
4011 /* All cleanups must be on the function_obstack. */
4012 push_obstacks_nochange ();
4013 resume_temporary_allocation ();
4015 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4016 DECL_RTL (cond) = flag;
4018 /* Conditionalize the cleanup. */
4019 cleanup = build (COND_EXPR, void_type_node,
4020 truthvalue_conversion (cond),
4021 cleanup, integer_zero_node);
4022 cleanup = fold (cleanup);
4026 cleanups = thisblock->data.block.cleanup_ptr;
4029 /* All cleanups must be on the function_obstack. */
4030 push_obstacks_nochange ();
4031 resume_temporary_allocation ();
4032 cleanup = unsave_expr (cleanup);
4035 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
4038 /* If this block has a cleanup, it belongs in stack_block_stack. */
4039 stack_block_stack = thisblock;
4046 /* If this was optimized so that there is no exception region for the
4047 cleanup, then mark the TREE_LIST node, so that we can later tell
4048 if we need to call expand_eh_region_end. */
4049 if (! using_eh_for_cleanups_p
4050 || expand_eh_region_start_tree (decl, cleanup))
4051 TREE_ADDRESSABLE (t) = 1;
4052 /* If that started a new EH region, we're in a new block. */
4053 thisblock = block_stack;
4060 thisblock->data.block.last_unconditional_cleanup
4061 = emit_insns_after (seq,
4062 thisblock->data.block.last_unconditional_cleanup);
4066 thisblock->data.block.last_unconditional_cleanup
4068 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4074 /* Like expand_decl_cleanup, but suppress generating an exception handler
4075 to perform the cleanup. */
4079 expand_decl_cleanup_no_eh (decl, cleanup)
4082 int save_eh = using_eh_for_cleanups_p;
4085 using_eh_for_cleanups_p = 0;
4086 result = expand_decl_cleanup (decl, cleanup);
4087 using_eh_for_cleanups_p = save_eh;
4093 /* Arrange for the top element of the dynamic cleanup chain to be
4094 popped if we exit the current binding contour. DECL is the
4095 associated declaration, if any, otherwise NULL_TREE. If the
4096 current contour is left via an exception, then __sjthrow will pop
4097 the top element off the dynamic cleanup chain. The code that
4098 avoids doing the action we push into the cleanup chain in the
4099 exceptional case is contained in expand_cleanups.
4101 This routine is only used by expand_eh_region_start, and that is
4102 the only way in which an exception region should be started. This
4103 routine is only used when using the setjmp/longjmp codegen method
4104 for exception handling. */
4107 expand_dcc_cleanup (decl)
4110 struct nesting *thisblock;
4113 /* Error if we are not in any block. */
4114 if (cfun == 0 || block_stack == 0)
4116 thisblock = block_stack;
4118 /* Record the cleanup for the dynamic handler chain. */
4120 /* All cleanups must be on the function_obstack. */
4121 push_obstacks_nochange ();
4122 resume_temporary_allocation ();
4123 cleanup = make_node (POPDCC_EXPR);
4126 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4127 thisblock->data.block.cleanups
4128 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4130 /* If this block has a cleanup, it belongs in stack_block_stack. */
4131 stack_block_stack = thisblock;
4135 /* Arrange for the top element of the dynamic handler chain to be
4136 popped if we exit the current binding contour. DECL is the
4137 associated declaration, if any, otherwise NULL_TREE. If the current
4138 contour is left via an exception, then __sjthrow will pop the top
4139 element off the dynamic handler chain. The code that avoids doing
4140 the action we push into the handler chain in the exceptional case
4141 is contained in expand_cleanups.
4143 This routine is only used by expand_eh_region_start, and that is
4144 the only way in which an exception region should be started. This
4145 routine is only used when using the setjmp/longjmp codegen method
4146 for exception handling. */
4149 expand_dhc_cleanup (decl)
4152 struct nesting *thisblock;
4155 /* Error if we are not in any block. */
4156 if (cfun == 0 || block_stack == 0)
4158 thisblock = block_stack;
4160 /* Record the cleanup for the dynamic handler chain. */
4162 /* All cleanups must be on the function_obstack. */
4163 push_obstacks_nochange ();
4164 resume_temporary_allocation ();
4165 cleanup = make_node (POPDHC_EXPR);
4168 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4169 thisblock->data.block.cleanups
4170 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4172 /* If this block has a cleanup, it belongs in stack_block_stack. */
4173 stack_block_stack = thisblock;
4177 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4178 DECL_ELTS is the list of elements that belong to DECL's type.
4179 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4182 expand_anon_union_decl (decl, cleanup, decl_elts)
4183 tree decl, cleanup, decl_elts;
4185 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4189 /* If any of the elements are addressable, so is the entire union. */
4190 for (t = decl_elts; t; t = TREE_CHAIN (t))
4191 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4193 TREE_ADDRESSABLE (decl) = 1;
4198 expand_decl_cleanup (decl, cleanup);
4199 x = DECL_RTL (decl);
4201 /* Go through the elements, assigning RTL to each. */
4202 for (t = decl_elts; t; t = TREE_CHAIN (t))
4204 tree decl_elt = TREE_VALUE (t);
4205 tree cleanup_elt = TREE_PURPOSE (t);
4206 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4208 /* Propagate the union's alignment to the elements. */
4209 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4211 /* If the element has BLKmode and the union doesn't, the union is
4212 aligned such that the element doesn't need to have BLKmode, so
4213 change the element's mode to the appropriate one for its size. */
4214 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4215 DECL_MODE (decl_elt) = mode
4216 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4218 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4219 instead create a new MEM rtx with the proper mode. */
4220 if (GET_CODE (x) == MEM)
4222 if (mode == GET_MODE (x))
4223 DECL_RTL (decl_elt) = x;
4226 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4227 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4228 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
4231 else if (GET_CODE (x) == REG)
4233 if (mode == GET_MODE (x))
4234 DECL_RTL (decl_elt) = x;
4236 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4241 /* Record the cleanup if there is one. */
4244 thisblock->data.block.cleanups
4245 = temp_tree_cons (decl_elt, cleanup_elt,
4246 thisblock->data.block.cleanups);
4250 /* Expand a list of cleanups LIST.
4251 Elements may be expressions or may be nested lists.
4253 If DONT_DO is nonnull, then any list-element
4254 whose TREE_PURPOSE matches DONT_DO is omitted.
4255 This is sometimes used to avoid a cleanup associated with
4256 a value that is being returned out of the scope.
4258 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4259 goto and handle protection regions specially in that case.
4261 If REACHABLE, we emit code, otherwise just inform the exception handling
4262 code about this finalization. */
4265 expand_cleanups (list, dont_do, in_fixup, reachable)
4272 for (tail = list; tail; tail = TREE_CHAIN (tail))
4273 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4275 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4276 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4281 tree cleanup = TREE_VALUE (tail);
4283 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4284 if (TREE_CODE (cleanup) != POPDHC_EXPR
4285 && TREE_CODE (cleanup) != POPDCC_EXPR
4286 /* See expand_eh_region_start_tree for this case. */
4287 && ! TREE_ADDRESSABLE (tail))
4289 cleanup = protect_with_terminate (cleanup);
4290 expand_eh_region_end (cleanup);
4296 /* Cleanups may be run multiple times. For example,
4297 when exiting a binding contour, we expand the
4298 cleanups associated with that contour. When a goto
4299 within that binding contour has a target outside that
4300 contour, it will expand all cleanups from its scope to
4301 the target. Though the cleanups are expanded multiple
4302 times, the control paths are non-overlapping so the
4303 cleanups will not be executed twice. */
4305 /* We may need to protect fixups with rethrow regions. */
4306 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4309 expand_fixup_region_start ();
4311 /* The cleanup might contain try-blocks, so we have to
4312 preserve our current queue. */
4314 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4317 expand_fixup_region_end (TREE_VALUE (tail));
4324 /* Mark when the context we are emitting RTL for as a conditional
4325 context, so that any cleanup actions we register with
4326 expand_decl_init will be properly conditionalized when those
4327 cleanup actions are later performed. Must be called before any
4328 expression (tree) is expanded that is within a conditional context. */
4331 start_cleanup_deferral ()
4333 /* block_stack can be NULL if we are inside the parameter list. It is
4334 OK to do nothing, because cleanups aren't possible here. */
4336 ++block_stack->data.block.conditional_code;
4339 /* Mark the end of a conditional region of code. Because cleanup
4340 deferrals may be nested, we may still be in a conditional region
4341 after we end the currently deferred cleanups, only after we end all
4342 deferred cleanups, are we back in unconditional code. */
4345 end_cleanup_deferral ()
4347 /* block_stack can be NULL if we are inside the parameter list. It is
4348 OK to do nothing, because cleanups aren't possible here. */
4350 --block_stack->data.block.conditional_code;
4353 /* Move all cleanups from the current block_stack
4354 to the containing block_stack, where they are assumed to
4355 have been created. If anything can cause a temporary to
4356 be created, but not expanded for more than one level of
4357 block_stacks, then this code will have to change. */
4362 struct nesting *block = block_stack;
4363 struct nesting *outer = block->next;
4365 outer->data.block.cleanups
4366 = chainon (block->data.block.cleanups,
4367 outer->data.block.cleanups);
4368 block->data.block.cleanups = 0;
4372 last_cleanup_this_contour ()
4374 if (block_stack == 0)
4377 return block_stack->data.block.cleanups;
4380 /* Return 1 if there are any pending cleanups at this point.
4381 If THIS_CONTOUR is nonzero, check the current contour as well.
4382 Otherwise, look only at the contours that enclose this one. */
4385 any_pending_cleanups (this_contour)
4388 struct nesting *block;
4390 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4393 if (this_contour && block_stack->data.block.cleanups != NULL)
4395 if (block_stack->data.block.cleanups == 0
4396 && block_stack->data.block.outer_cleanups == 0)
4399 for (block = block_stack->next; block; block = block->next)
4400 if (block->data.block.cleanups != 0)
4406 /* Enter a case (Pascal) or switch (C) statement.
4407 Push a block onto case_stack and nesting_stack
4408 to accumulate the case-labels that are seen
4409 and to record the labels generated for the statement.
4411 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4412 Otherwise, this construct is transparent for `exit_something'.
4414 EXPR is the index-expression to be dispatched on.
4415 TYPE is its nominal type. We could simply convert EXPR to this type,
4416 but instead we take short cuts. */
4419 expand_start_case (exit_flag, expr, type, printname)
4423 const char *printname;
4425 register struct nesting *thiscase = ALLOC_NESTING ();
4427 /* Make an entry on case_stack for the case we are entering. */
4429 thiscase->next = case_stack;
4430 thiscase->all = nesting_stack;
4431 thiscase->depth = ++nesting_depth;
4432 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4433 thiscase->data.case_stmt.case_list = 0;
4434 thiscase->data.case_stmt.index_expr = expr;
4435 thiscase->data.case_stmt.nominal_type = type;
4436 thiscase->data.case_stmt.default_label = 0;
4437 thiscase->data.case_stmt.num_ranges = 0;
4438 thiscase->data.case_stmt.printname = printname;
4439 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4440 case_stack = thiscase;
4441 nesting_stack = thiscase;
4443 do_pending_stack_adjust ();
4445 /* Make sure case_stmt.start points to something that won't
4446 need any transformation before expand_end_case. */
4447 if (GET_CODE (get_last_insn ()) != NOTE)
4448 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4450 thiscase->data.case_stmt.start = get_last_insn ();
4452 start_cleanup_deferral ();
4456 /* Start a "dummy case statement" within which case labels are invalid
4457 and are not connected to any larger real case statement.
4458 This can be used if you don't want to let a case statement jump
4459 into the middle of certain kinds of constructs. */
4462 expand_start_case_dummy ()
4464 register struct nesting *thiscase = ALLOC_NESTING ();
4466 /* Make an entry on case_stack for the dummy. */
4468 thiscase->next = case_stack;
4469 thiscase->all = nesting_stack;
4470 thiscase->depth = ++nesting_depth;
4471 thiscase->exit_label = 0;
4472 thiscase->data.case_stmt.case_list = 0;
4473 thiscase->data.case_stmt.start = 0;
4474 thiscase->data.case_stmt.nominal_type = 0;
4475 thiscase->data.case_stmt.default_label = 0;
4476 thiscase->data.case_stmt.num_ranges = 0;
4477 case_stack = thiscase;
4478 nesting_stack = thiscase;
4479 start_cleanup_deferral ();
4482 /* End a dummy case statement. */
4485 expand_end_case_dummy ()
4487 end_cleanup_deferral ();
4488 POPSTACK (case_stack);
4491 /* Return the data type of the index-expression
4492 of the innermost case statement, or null if none. */
4495 case_index_expr_type ()
4498 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4505 /* If this is the first label, warn if any insns have been emitted. */
4506 if (case_stack->data.case_stmt.line_number_status >= 0)
4510 restore_line_number_status
4511 (case_stack->data.case_stmt.line_number_status);
4512 case_stack->data.case_stmt.line_number_status = -1;
4514 for (insn = case_stack->data.case_stmt.start;
4516 insn = NEXT_INSN (insn))
4518 if (GET_CODE (insn) == CODE_LABEL)
4520 if (GET_CODE (insn) != NOTE
4521 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4524 insn = PREV_INSN (insn);
4525 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4527 /* If insn is zero, then there must have been a syntax error. */
4529 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4530 NOTE_LINE_NUMBER(insn),
4531 "unreachable code at beginning of %s",
4532 case_stack->data.case_stmt.printname);
4539 /* Accumulate one case or default label inside a case or switch statement.
4540 VALUE is the value of the case (a null pointer, for a default label).
4541 The function CONVERTER, when applied to arguments T and V,
4542 converts the value V to the type T.
4544 If not currently inside a case or switch statement, return 1 and do
4545 nothing. The caller will print a language-specific error message.
4546 If VALUE is a duplicate or overlaps, return 2 and do nothing
4547 except store the (first) duplicate node in *DUPLICATE.
4548 If VALUE is out of range, return 3 and do nothing.
4549 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4550 Return 0 on success.
4552 Extended to handle range statements. */
4555 pushcase (value, converter, label, duplicate)
4556 register tree value;
4557 tree (*converter) PARAMS ((tree, tree));
4558 register tree label;
4564 /* Fail if not inside a real case statement. */
4565 if (! (case_stack && case_stack->data.case_stmt.start))
4568 if (stack_block_stack
4569 && stack_block_stack->depth > case_stack->depth)
4572 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4573 nominal_type = case_stack->data.case_stmt.nominal_type;
4575 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4576 if (index_type == error_mark_node)
4579 /* Convert VALUE to the type in which the comparisons are nominally done. */
4581 value = (*converter) (nominal_type, value);
4585 /* Fail if this value is out of range for the actual type of the index
4586 (which may be narrower than NOMINAL_TYPE). */
4588 && (TREE_CONSTANT_OVERFLOW (value)
4589 || ! int_fits_type_p (value, index_type)))
4592 /* Fail if this is a duplicate or overlaps another entry. */
4595 if (case_stack->data.case_stmt.default_label != 0)
4597 *duplicate = case_stack->data.case_stmt.default_label;
4600 case_stack->data.case_stmt.default_label = label;
4603 return add_case_node (value, value, label, duplicate);
4605 expand_label (label);
4609 /* Like pushcase but this case applies to all values between VALUE1 and
4610 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4611 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4612 starts at VALUE1 and ends at the highest value of the index type.
4613 If both are NULL, this case applies to all values.
4615 The return value is the same as that of pushcase but there is one
4616 additional error code: 4 means the specified range was empty. */
4619 pushcase_range (value1, value2, converter, label, duplicate)
4620 register tree value1, value2;
4621 tree (*converter) PARAMS ((tree, tree));
4622 register tree label;
4628 /* Fail if not inside a real case statement. */
4629 if (! (case_stack && case_stack->data.case_stmt.start))
4632 if (stack_block_stack
4633 && stack_block_stack->depth > case_stack->depth)
4636 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4637 nominal_type = case_stack->data.case_stmt.nominal_type;
4639 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4640 if (index_type == error_mark_node)
4645 /* Convert VALUEs to type in which the comparisons are nominally done
4646 and replace any unspecified value with the corresponding bound. */
4648 value1 = TYPE_MIN_VALUE (index_type);
4650 value2 = TYPE_MAX_VALUE (index_type);
4652 /* Fail if the range is empty. Do this before any conversion since
4653 we want to allow out-of-range empty ranges. */
4654 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4657 /* If the max was unbounded, use the max of the nominal_type we are
4658 converting to. Do this after the < check above to suppress false
4661 value2 = TYPE_MAX_VALUE (nominal_type);
4663 value1 = (*converter) (nominal_type, value1);
4664 value2 = (*converter) (nominal_type, value2);
4666 /* Fail if these values are out of range. */
4667 if (TREE_CONSTANT_OVERFLOW (value1)
4668 || ! int_fits_type_p (value1, index_type))
4671 if (TREE_CONSTANT_OVERFLOW (value2)
4672 || ! int_fits_type_p (value2, index_type))
4675 return add_case_node (value1, value2, label, duplicate);
4678 /* Do the actual insertion of a case label for pushcase and pushcase_range
4679 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4680 slowdown for large switch statements. */
4683 add_case_node (low, high, label, duplicate)
4688 struct case_node *p, **q, *r;
4690 q = &case_stack->data.case_stmt.case_list;
4697 /* Keep going past elements distinctly greater than HIGH. */
4698 if (tree_int_cst_lt (high, p->low))
4701 /* or distinctly less than LOW. */
4702 else if (tree_int_cst_lt (p->high, low))
4707 /* We have an overlap; this is an error. */
4708 *duplicate = p->code_label;
4713 /* Add this label to the chain, and succeed.
4714 Copy LOW, HIGH so they are on temporary rather than momentary
4715 obstack and will thus survive till the end of the case statement. */
4717 r = (struct case_node *) oballoc (sizeof (struct case_node));
4718 r->low = copy_node (low);
4720 /* If the bounds are equal, turn this into the one-value case. */
4722 if (tree_int_cst_equal (low, high))
4726 r->high = copy_node (high);
4727 case_stack->data.case_stmt.num_ranges++;
4730 r->code_label = label;
4731 expand_label (label);
4741 struct case_node *s;
4747 if (! (b = p->balance))
4748 /* Growth propagation from left side. */
4755 if ((p->left = s = r->right))
4764 if ((r->parent = s))
4772 case_stack->data.case_stmt.case_list = r;
4775 /* r->balance == +1 */
4780 struct case_node *t = r->right;
4782 if ((p->left = s = t->right))
4786 if ((r->right = s = t->left))
4800 if ((t->parent = s))
4808 case_stack->data.case_stmt.case_list = t;
4815 /* p->balance == +1; growth of left side balances the node. */
4825 if (! (b = p->balance))
4826 /* Growth propagation from right side. */
4834 if ((p->right = s = r->left))
4842 if ((r->parent = s))
4851 case_stack->data.case_stmt.case_list = r;
4855 /* r->balance == -1 */
4859 struct case_node *t = r->left;
4861 if ((p->right = s = t->left))
4866 if ((r->left = s = t->right))
4880 if ((t->parent = s))
4889 case_stack->data.case_stmt.case_list = t;
4895 /* p->balance == -1; growth of right side balances the node. */
4909 /* Returns the number of possible values of TYPE.
4910 Returns -1 if the number is unknown, variable, or if the number does not
4911 fit in a HOST_WIDE_INT.
4912 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4913 do not increase monotonically (there may be duplicates);
4914 to 1 if the values increase monotonically, but not always by 1;
4915 otherwise sets it to 0. */
4918 all_cases_count (type, spareness)
4923 HOST_WIDE_INT count, minval, lastval;
4927 switch (TREE_CODE (type))
4934 count = 1 << BITS_PER_UNIT;
4939 if (TYPE_MAX_VALUE (type) != 0
4940 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4941 TYPE_MIN_VALUE (type))))
4942 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4943 convert (type, integer_zero_node))))
4944 && host_integerp (t, 1))
4945 count = tree_low_cst (t, 1);
4951 /* Don't waste time with enumeral types with huge values. */
4952 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4953 || TYPE_MAX_VALUE (type) == 0
4954 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4957 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4960 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4962 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
4964 if (*spareness == 2 || thisval < lastval)
4966 else if (thisval != minval + count)
4976 #define BITARRAY_TEST(ARRAY, INDEX) \
4977 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4978 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4979 #define BITARRAY_SET(ARRAY, INDEX) \
4980 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4981 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4983 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4984 with the case values we have seen, assuming the case expression
4986 SPARSENESS is as determined by all_cases_count.
4988 The time needed is proportional to COUNT, unless
4989 SPARSENESS is 2, in which case quadratic time is needed. */
4992 mark_seen_cases (type, cases_seen, count, sparseness)
4994 unsigned char *cases_seen;
4995 HOST_WIDE_INT count;
4998 tree next_node_to_try = NULL_TREE;
4999 HOST_WIDE_INT next_node_offset = 0;
5001 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5002 tree val = make_node (INTEGER_CST);
5004 TREE_TYPE (val) = type;
5007 else if (sparseness == 2)
5010 unsigned HOST_WIDE_INT xlo;
5012 /* This less efficient loop is only needed to handle
5013 duplicate case values (multiple enum constants
5014 with the same value). */
5015 TREE_TYPE (val) = TREE_TYPE (root->low);
5016 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5017 t = TREE_CHAIN (t), xlo++)
5019 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5020 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5024 /* Keep going past elements distinctly greater than VAL. */
5025 if (tree_int_cst_lt (val, n->low))
5028 /* or distinctly less than VAL. */
5029 else if (tree_int_cst_lt (n->high, val))
5034 /* We have found a matching range. */
5035 BITARRAY_SET (cases_seen, xlo);
5045 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5047 for (n = root; n; n = n->right)
5049 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5050 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5051 while ( ! tree_int_cst_lt (n->high, val))
5053 /* Calculate (into xlo) the "offset" of the integer (val).
5054 The element with lowest value has offset 0, the next smallest
5055 element has offset 1, etc. */
5057 unsigned HOST_WIDE_INT xlo;
5061 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5063 /* The TYPE_VALUES will be in increasing order, so
5064 starting searching where we last ended. */
5065 t = next_node_to_try;
5066 xlo = next_node_offset;
5072 t = TYPE_VALUES (type);
5075 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5077 next_node_to_try = TREE_CHAIN (t);
5078 next_node_offset = xlo + 1;
5083 if (t == next_node_to_try)
5092 t = TYPE_MIN_VALUE (type);
5094 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5098 add_double (xlo, xhi,
5099 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5103 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5104 BITARRAY_SET (cases_seen, xlo);
5106 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5108 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5114 /* Called when the index of a switch statement is an enumerated type
5115 and there is no default label.
5117 Checks that all enumeration literals are covered by the case
5118 expressions of a switch. Also, warn if there are any extra
5119 switch cases that are *not* elements of the enumerated type.
5121 If all enumeration literals were covered by the case expressions,
5122 turn one of the expressions into the default expression since it should
5123 not be possible to fall through such a switch. */
5126 check_for_full_enumeration_handling (type)
5129 register struct case_node *n;
5130 register tree chain;
5131 #if 0 /* variable used by 'if 0'ed code below. */
5132 register struct case_node **l;
5136 /* True iff the selector type is a numbered set mode. */
5139 /* The number of possible selector values. */
5142 /* For each possible selector value. a one iff it has been matched
5143 by a case value alternative. */
5144 unsigned char *cases_seen;
5146 /* The allocated size of cases_seen, in chars. */
5147 HOST_WIDE_INT bytes_needed;
5152 size = all_cases_count (type, &sparseness);
5153 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5155 if (size > 0 && size < 600000
5156 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5157 this optimization if we don't have enough memory rather than
5158 aborting, as xmalloc would do. */
5159 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5162 tree v = TYPE_VALUES (type);
5164 /* The time complexity of this code is normally O(N), where
5165 N being the number of members in the enumerated type.
5166 However, if type is a ENUMERAL_TYPE whose values do not
5167 increase monotonically, O(N*log(N)) time may be needed. */
5169 mark_seen_cases (type, cases_seen, size, sparseness);
5171 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5172 if (BITARRAY_TEST(cases_seen, i) == 0)
5173 warning ("enumeration value `%s' not handled in switch",
5174 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5179 /* Now we go the other way around; we warn if there are case
5180 expressions that don't correspond to enumerators. This can
5181 occur since C and C++ don't enforce type-checking of
5182 assignments to enumeration variables. */
5184 if (case_stack->data.case_stmt.case_list
5185 && case_stack->data.case_stmt.case_list->left)
5186 case_stack->data.case_stmt.case_list
5187 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5189 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5191 for (chain = TYPE_VALUES (type);
5192 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5193 chain = TREE_CHAIN (chain))
5198 if (TYPE_NAME (type) == 0)
5199 warning ("case value `%ld' not in enumerated type",
5200 (long) TREE_INT_CST_LOW (n->low));
5202 warning ("case value `%ld' not in enumerated type `%s'",
5203 (long) TREE_INT_CST_LOW (n->low),
5204 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5207 : DECL_NAME (TYPE_NAME (type))));
5209 if (!tree_int_cst_equal (n->low, n->high))
5211 for (chain = TYPE_VALUES (type);
5212 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5213 chain = TREE_CHAIN (chain))
5218 if (TYPE_NAME (type) == 0)
5219 warning ("case value `%ld' not in enumerated type",
5220 (long) TREE_INT_CST_LOW (n->high));
5222 warning ("case value `%ld' not in enumerated type `%s'",
5223 (long) TREE_INT_CST_LOW (n->high),
5224 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5227 : DECL_NAME (TYPE_NAME (type))));
5233 /* ??? This optimization is disabled because it causes valid programs to
5234 fail. ANSI C does not guarantee that an expression with enum type
5235 will have a value that is the same as one of the enumeration literals. */
5237 /* If all values were found as case labels, make one of them the default
5238 label. Thus, this switch will never fall through. We arbitrarily pick
5239 the last one to make the default since this is likely the most
5240 efficient choice. */
5244 for (l = &case_stack->data.case_stmt.case_list;
5249 case_stack->data.case_stmt.default_label = (*l)->code_label;
5256 /* Terminate a case (Pascal) or switch (C) statement
5257 in which ORIG_INDEX is the expression to be tested.
5258 Generate the code to test it and jump to the right place. */
5261 expand_end_case (orig_index)
5264 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5265 rtx default_label = 0;
5266 register struct case_node *n;
5274 register struct nesting *thiscase = case_stack;
5275 tree index_expr, index_type;
5278 /* Don't crash due to previous errors. */
5279 if (thiscase == NULL)
5282 table_label = gen_label_rtx ();
5283 index_expr = thiscase->data.case_stmt.index_expr;
5284 index_type = TREE_TYPE (index_expr);
5285 unsignedp = TREE_UNSIGNED (index_type);
5287 do_pending_stack_adjust ();
5289 /* This might get an spurious warning in the presence of a syntax error;
5290 it could be fixed by moving the call to check_seenlabel after the
5291 check for error_mark_node, and copying the code of check_seenlabel that
5292 deals with case_stack->data.case_stmt.line_number_status /
5293 restore_line_number_status in front of the call to end_cleanup_deferral;
5294 However, this might miss some useful warnings in the presence of
5295 non-syntax errors. */
5298 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5299 if (index_type != error_mark_node)
5301 /* If switch expression was an enumerated type, check that all
5302 enumeration literals are covered by the cases.
5303 No sense trying this if there's a default case, however. */
5305 if (!thiscase->data.case_stmt.default_label
5306 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5307 && TREE_CODE (index_expr) != INTEGER_CST)
5308 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5310 /* If we don't have a default-label, create one here,
5311 after the body of the switch. */
5312 if (thiscase->data.case_stmt.default_label == 0)
5314 thiscase->data.case_stmt.default_label
5315 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5316 expand_label (thiscase->data.case_stmt.default_label);
5318 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5320 before_case = get_last_insn ();
5322 if (thiscase->data.case_stmt.case_list
5323 && thiscase->data.case_stmt.case_list->left)
5324 thiscase->data.case_stmt.case_list
5325 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
5327 /* Simplify the case-list before we count it. */
5328 group_case_nodes (thiscase->data.case_stmt.case_list);
5330 /* Get upper and lower bounds of case values.
5331 Also convert all the case values to the index expr's data type. */
5334 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5336 /* Check low and high label values are integers. */
5337 if (TREE_CODE (n->low) != INTEGER_CST)
5339 if (TREE_CODE (n->high) != INTEGER_CST)
5342 n->low = convert (index_type, n->low);
5343 n->high = convert (index_type, n->high);
5345 /* Count the elements and track the largest and smallest
5346 of them (treating them as signed even if they are not). */
5354 if (INT_CST_LT (n->low, minval))
5356 if (INT_CST_LT (maxval, n->high))
5359 /* A range counts double, since it requires two compares. */
5360 if (! tree_int_cst_equal (n->low, n->high))
5364 orig_minval = minval;
5366 /* Compute span of values. */
5368 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5370 end_cleanup_deferral ();
5374 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5376 emit_jump (default_label);
5379 /* If range of values is much bigger than number of values,
5380 make a sequence of conditional branches instead of a dispatch.
5381 If the switch-index is a constant, do it this way
5382 because we can optimize it. */
5384 #ifndef CASE_VALUES_THRESHOLD
5386 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5388 /* If machine does not have a case insn that compares the
5389 bounds, this means extra overhead for dispatch tables
5390 which raises the threshold for using them. */
5391 #define CASE_VALUES_THRESHOLD 5
5392 #endif /* HAVE_casesi */
5393 #endif /* CASE_VALUES_THRESHOLD */
5395 else if (count < CASE_VALUES_THRESHOLD
5396 || compare_tree_int (range, 10 * count) > 0
5397 /* RANGE may be signed, and really large ranges will show up
5398 as negative numbers. */
5399 || compare_tree_int (range, 0) < 0
5400 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5403 || TREE_CODE (index_expr) == INTEGER_CST
5404 /* These will reduce to a constant. */
5405 || (TREE_CODE (index_expr) == CALL_EXPR
5406 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5407 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5408 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5409 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5410 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5411 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5413 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5415 /* If the index is a short or char that we do not have
5416 an insn to handle comparisons directly, convert it to
5417 a full integer now, rather than letting each comparison
5418 generate the conversion. */
5420 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5421 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5422 == CODE_FOR_nothing))
5424 enum machine_mode wider_mode;
5425 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5426 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5427 if (cmp_optab->handlers[(int) wider_mode].insn_code
5428 != CODE_FOR_nothing)
5430 index = convert_to_mode (wider_mode, index, unsignedp);
5436 do_pending_stack_adjust ();
5438 index = protect_from_queue (index, 0);
5439 if (GET_CODE (index) == MEM)
5440 index = copy_to_reg (index);
5441 if (GET_CODE (index) == CONST_INT
5442 || TREE_CODE (index_expr) == INTEGER_CST)
5444 /* Make a tree node with the proper constant value
5445 if we don't already have one. */
5446 if (TREE_CODE (index_expr) != INTEGER_CST)
5449 = build_int_2 (INTVAL (index),
5450 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5451 index_expr = convert (index_type, index_expr);
5454 /* For constant index expressions we need only
5455 issue a unconditional branch to the appropriate
5456 target code. The job of removing any unreachable
5457 code is left to the optimisation phase if the
5458 "-O" option is specified. */
5459 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5460 if (! tree_int_cst_lt (index_expr, n->low)
5461 && ! tree_int_cst_lt (n->high, index_expr))
5465 emit_jump (label_rtx (n->code_label));
5467 emit_jump (default_label);
5471 /* If the index expression is not constant we generate
5472 a binary decision tree to select the appropriate
5473 target code. This is done as follows:
5475 The list of cases is rearranged into a binary tree,
5476 nearly optimal assuming equal probability for each case.
5478 The tree is transformed into RTL, eliminating
5479 redundant test conditions at the same time.
5481 If program flow could reach the end of the
5482 decision tree an unconditional jump to the
5483 default code is emitted. */
5486 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5487 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5488 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5490 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5491 default_label, index_type);
5492 emit_jump_if_reachable (default_label);
5501 enum machine_mode index_mode = SImode;
5502 int index_bits = GET_MODE_BITSIZE (index_mode);
5504 enum machine_mode op_mode;
5506 /* Convert the index to SImode. */
5507 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5508 > GET_MODE_BITSIZE (index_mode))
5510 enum machine_mode omode = TYPE_MODE (index_type);
5511 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5513 /* We must handle the endpoints in the original mode. */
5514 index_expr = build (MINUS_EXPR, index_type,
5515 index_expr, minval);
5516 minval = integer_zero_node;
5517 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5518 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5519 omode, 1, 0, default_label);
5520 /* Now we can safely truncate. */
5521 index = convert_to_mode (index_mode, index, 0);
5525 if (TYPE_MODE (index_type) != index_mode)
5527 index_expr = convert (type_for_size (index_bits, 0),
5529 index_type = TREE_TYPE (index_expr);
5532 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5535 index = protect_from_queue (index, 0);
5536 do_pending_stack_adjust ();
5538 op_mode = insn_data[(int)CODE_FOR_casesi].operand[0].mode;
5539 if (! (*insn_data[(int)CODE_FOR_casesi].operand[0].predicate)
5541 index = copy_to_mode_reg (op_mode, index);
5543 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5545 op_mode = insn_data[(int)CODE_FOR_casesi].operand[1].mode;
5546 if (! (*insn_data[(int)CODE_FOR_casesi].operand[1].predicate)
5548 op1 = copy_to_mode_reg (op_mode, op1);
5550 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5552 op_mode = insn_data[(int)CODE_FOR_casesi].operand[2].mode;
5553 if (! (*insn_data[(int)CODE_FOR_casesi].operand[2].predicate)
5555 op2 = copy_to_mode_reg (op_mode, op2);
5557 emit_jump_insn (gen_casesi (index, op1, op2,
5558 table_label, default_label));
5562 #ifdef HAVE_tablejump
5563 if (! win && HAVE_tablejump)
5565 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5566 fold (build (MINUS_EXPR, index_type,
5567 index_expr, minval)));
5568 index_type = TREE_TYPE (index_expr);
5569 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5571 index = protect_from_queue (index, 0);
5572 do_pending_stack_adjust ();
5574 do_tablejump (index, TYPE_MODE (index_type),
5575 expand_expr (range, NULL_RTX, VOIDmode, 0),
5576 table_label, default_label);
5583 /* Get table of labels to jump to, in order of case index. */
5585 ncases = TREE_INT_CST_LOW (range) + 1;
5586 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5587 bzero ((char *) labelvec, ncases * sizeof (rtx));
5589 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5591 register HOST_WIDE_INT i
5592 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5597 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5598 if (i + TREE_INT_CST_LOW (orig_minval)
5599 == TREE_INT_CST_LOW (n->high))
5605 /* Fill in the gaps with the default. */
5606 for (i = 0; i < ncases; i++)
5607 if (labelvec[i] == 0)
5608 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5610 /* Output the table */
5611 emit_label (table_label);
5613 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5614 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5615 gen_rtx_LABEL_REF (Pmode, table_label),
5616 gen_rtvec_v (ncases, labelvec),
5617 const0_rtx, const0_rtx));
5619 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5620 gen_rtvec_v (ncases, labelvec)));
5622 /* If the case insn drops through the table,
5623 after the table we must jump to the default-label.
5624 Otherwise record no drop-through after the table. */
5625 #ifdef CASE_DROPS_THROUGH
5626 emit_jump (default_label);
5632 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5633 reorder_insns (before_case, get_last_insn (),
5634 thiscase->data.case_stmt.start);
5637 end_cleanup_deferral ();
5639 if (thiscase->exit_label)
5640 emit_label (thiscase->exit_label);
5642 POPSTACK (case_stack);
5647 /* Convert the tree NODE into a list linked by the right field, with the left
5648 field zeroed. RIGHT is used for recursion; it is a list to be placed
5649 rightmost in the resulting list. */
5651 static struct case_node *
5652 case_tree2list (node, right)
5653 struct case_node *node, *right;
5655 struct case_node *left;
5658 right = case_tree2list (node->right, right);
5660 node->right = right;
5661 if ((left = node->left))
5664 return case_tree2list (left, node);
5670 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5673 do_jump_if_equal (op1, op2, label, unsignedp)
5674 rtx op1, op2, label;
5677 if (GET_CODE (op1) == CONST_INT
5678 && GET_CODE (op2) == CONST_INT)
5680 if (INTVAL (op1) == INTVAL (op2))
5685 enum machine_mode mode = GET_MODE (op1);
5686 if (mode == VOIDmode)
5687 mode = GET_MODE (op2);
5688 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5693 /* Not all case values are encountered equally. This function
5694 uses a heuristic to weight case labels, in cases where that
5695 looks like a reasonable thing to do.
5697 Right now, all we try to guess is text, and we establish the
5700 chars above space: 16
5709 If we find any cases in the switch that are not either -1 or in the range
5710 of valid ASCII characters, or are control characters other than those
5711 commonly used with "\", don't treat this switch scanning text.
5713 Return 1 if these nodes are suitable for cost estimation, otherwise
5717 estimate_case_costs (node)
5720 tree min_ascii = build_int_2 (-1, -1);
5721 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5725 /* If we haven't already made the cost table, make it now. Note that the
5726 lower bound of the table is -1, not zero. */
5728 if (cost_table == NULL)
5730 cost_table = cost_table_ + 1;
5732 for (i = 0; i < 128; i++)
5736 else if (ISPUNCT (i))
5738 else if (ISCNTRL (i))
5742 cost_table[' '] = 8;
5743 cost_table['\t'] = 4;
5744 cost_table['\0'] = 4;
5745 cost_table['\n'] = 2;
5746 cost_table['\f'] = 1;
5747 cost_table['\v'] = 1;
5748 cost_table['\b'] = 1;
5751 /* See if all the case expressions look like text. It is text if the
5752 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5753 as signed arithmetic since we don't want to ever access cost_table with a
5754 value less than -1. Also check that none of the constants in a range
5755 are strange control characters. */
5757 for (n = node; n; n = n->right)
5759 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5762 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5763 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5764 if (cost_table[i] < 0)
5768 /* All interesting values are within the range of interesting
5769 ASCII characters. */
5773 /* Scan an ordered list of case nodes
5774 combining those with consecutive values or ranges.
5776 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5779 group_case_nodes (head)
5782 case_node_ptr node = head;
5786 rtx lb = next_real_insn (label_rtx (node->code_label));
5788 case_node_ptr np = node;
5790 /* Try to group the successors of NODE with NODE. */
5791 while (((np = np->right) != 0)
5792 /* Do they jump to the same place? */
5793 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5794 || (lb != 0 && lb2 != 0
5795 && simplejump_p (lb)
5796 && simplejump_p (lb2)
5797 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5798 SET_SRC (PATTERN (lb2)))))
5799 /* Are their ranges consecutive? */
5800 && tree_int_cst_equal (np->low,
5801 fold (build (PLUS_EXPR,
5802 TREE_TYPE (node->high),
5805 /* An overflow is not consecutive. */
5806 && tree_int_cst_lt (node->high,
5807 fold (build (PLUS_EXPR,
5808 TREE_TYPE (node->high),
5810 integer_one_node))))
5812 node->high = np->high;
5814 /* NP is the first node after NODE which can't be grouped with it.
5815 Delete the nodes in between, and move on to that node. */
5821 /* Take an ordered list of case nodes
5822 and transform them into a near optimal binary tree,
5823 on the assumption that any target code selection value is as
5824 likely as any other.
5826 The transformation is performed by splitting the ordered
5827 list into two equal sections plus a pivot. The parts are
5828 then attached to the pivot as left and right branches. Each
5829 branch is then transformed recursively. */
5832 balance_case_nodes (head, parent)
5833 case_node_ptr *head;
5834 case_node_ptr parent;
5836 register case_node_ptr np;
5844 register case_node_ptr *npp;
5847 /* Count the number of entries on branch. Also count the ranges. */
5851 if (!tree_int_cst_equal (np->low, np->high))
5855 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5859 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5867 /* Split this list if it is long enough for that to help. */
5872 /* Find the place in the list that bisects the list's total cost,
5873 Here I gets half the total cost. */
5878 /* Skip nodes while their cost does not reach that amount. */
5879 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5880 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5881 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5884 npp = &(*npp)->right;
5889 /* Leave this branch lopsided, but optimize left-hand
5890 side and fill in `parent' fields for right-hand side. */
5892 np->parent = parent;
5893 balance_case_nodes (&np->left, np);
5894 for (; np->right; np = np->right)
5895 np->right->parent = np;
5899 /* If there are just three nodes, split at the middle one. */
5901 npp = &(*npp)->right;
5904 /* Find the place in the list that bisects the list's total cost,
5905 where ranges count as 2.
5906 Here I gets half the total cost. */
5907 i = (i + ranges + 1) / 2;
5910 /* Skip nodes while their cost does not reach that amount. */
5911 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5916 npp = &(*npp)->right;
5921 np->parent = parent;
5924 /* Optimize each of the two split parts. */
5925 balance_case_nodes (&np->left, np);
5926 balance_case_nodes (&np->right, np);
5930 /* Else leave this branch as one level,
5931 but fill in `parent' fields. */
5933 np->parent = parent;
5934 for (; np->right; np = np->right)
5935 np->right->parent = np;
5940 /* Search the parent sections of the case node tree
5941 to see if a test for the lower bound of NODE would be redundant.
5942 INDEX_TYPE is the type of the index expression.
5944 The instructions to generate the case decision tree are
5945 output in the same order as nodes are processed so it is
5946 known that if a parent node checks the range of the current
5947 node minus one that the current node is bounded at its lower
5948 span. Thus the test would be redundant. */
5951 node_has_low_bound (node, index_type)
5956 case_node_ptr pnode;
5958 /* If the lower bound of this node is the lowest value in the index type,
5959 we need not test it. */
5961 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5964 /* If this node has a left branch, the value at the left must be less
5965 than that at this node, so it cannot be bounded at the bottom and
5966 we need not bother testing any further. */
5971 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5972 node->low, integer_one_node));
5974 /* If the subtraction above overflowed, we can't verify anything.
5975 Otherwise, look for a parent that tests our value - 1. */
5977 if (! tree_int_cst_lt (low_minus_one, node->low))
5980 for (pnode = node->parent; pnode; pnode = pnode->parent)
5981 if (tree_int_cst_equal (low_minus_one, pnode->high))
5987 /* Search the parent sections of the case node tree
5988 to see if a test for the upper bound of NODE would be redundant.
5989 INDEX_TYPE is the type of the index expression.
5991 The instructions to generate the case decision tree are
5992 output in the same order as nodes are processed so it is
5993 known that if a parent node checks the range of the current
5994 node plus one that the current node is bounded at its upper
5995 span. Thus the test would be redundant. */
5998 node_has_high_bound (node, index_type)
6003 case_node_ptr pnode;
6005 /* If there is no upper bound, obviously no test is needed. */
6007 if (TYPE_MAX_VALUE (index_type) == NULL)
6010 /* If the upper bound of this node is the highest value in the type
6011 of the index expression, we need not test against it. */
6013 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6016 /* If this node has a right branch, the value at the right must be greater
6017 than that at this node, so it cannot be bounded at the top and
6018 we need not bother testing any further. */
6023 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6024 node->high, integer_one_node));
6026 /* If the addition above overflowed, we can't verify anything.
6027 Otherwise, look for a parent that tests our value + 1. */
6029 if (! tree_int_cst_lt (node->high, high_plus_one))
6032 for (pnode = node->parent; pnode; pnode = pnode->parent)
6033 if (tree_int_cst_equal (high_plus_one, pnode->low))
6039 /* Search the parent sections of the
6040 case node tree to see if both tests for the upper and lower
6041 bounds of NODE would be redundant. */
6044 node_is_bounded (node, index_type)
6048 return (node_has_low_bound (node, index_type)
6049 && node_has_high_bound (node, index_type));
6052 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6055 emit_jump_if_reachable (label)
6058 if (GET_CODE (get_last_insn ()) != BARRIER)
6062 /* Emit step-by-step code to select a case for the value of INDEX.
6063 The thus generated decision tree follows the form of the
6064 case-node binary tree NODE, whose nodes represent test conditions.
6065 INDEX_TYPE is the type of the index of the switch.
6067 Care is taken to prune redundant tests from the decision tree
6068 by detecting any boundary conditions already checked by
6069 emitted rtx. (See node_has_high_bound, node_has_low_bound
6070 and node_is_bounded, above.)
6072 Where the test conditions can be shown to be redundant we emit
6073 an unconditional jump to the target code. As a further
6074 optimization, the subordinates of a tree node are examined to
6075 check for bounded nodes. In this case conditional and/or
6076 unconditional jumps as a result of the boundary check for the
6077 current node are arranged to target the subordinates associated
6078 code for out of bound conditions on the current node.
6080 We can assume that when control reaches the code generated here,
6081 the index value has already been compared with the parents
6082 of this node, and determined to be on the same side of each parent
6083 as this node is. Thus, if this node tests for the value 51,
6084 and a parent tested for 52, we don't need to consider
6085 the possibility of a value greater than 51. If another parent
6086 tests for the value 50, then this node need not test anything. */
6089 emit_case_nodes (index, node, default_label, index_type)
6095 /* If INDEX has an unsigned type, we must make unsigned branches. */
6096 int unsignedp = TREE_UNSIGNED (index_type);
6097 enum machine_mode mode = GET_MODE (index);
6099 /* See if our parents have already tested everything for us.
6100 If they have, emit an unconditional jump for this node. */
6101 if (node_is_bounded (node, index_type))
6102 emit_jump (label_rtx (node->code_label));
6104 else if (tree_int_cst_equal (node->low, node->high))
6106 /* Node is single valued. First see if the index expression matches
6107 this node and then check our children, if any. */
6109 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6110 label_rtx (node->code_label), unsignedp);
6112 if (node->right != 0 && node->left != 0)
6114 /* This node has children on both sides.
6115 Dispatch to one side or the other
6116 by comparing the index value with this node's value.
6117 If one subtree is bounded, check that one first,
6118 so we can avoid real branches in the tree. */
6120 if (node_is_bounded (node->right, index_type))
6122 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6124 GT, NULL_RTX, mode, unsignedp, 0,
6125 label_rtx (node->right->code_label));
6126 emit_case_nodes (index, node->left, default_label, index_type);
6129 else if (node_is_bounded (node->left, index_type))
6131 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6133 LT, NULL_RTX, mode, unsignedp, 0,
6134 label_rtx (node->left->code_label));
6135 emit_case_nodes (index, node->right, default_label, index_type);
6140 /* Neither node is bounded. First distinguish the two sides;
6141 then emit the code for one side at a time. */
6144 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6146 /* See if the value is on the right. */
6147 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6149 GT, NULL_RTX, mode, unsignedp, 0,
6150 label_rtx (test_label));
6152 /* Value must be on the left.
6153 Handle the left-hand subtree. */
6154 emit_case_nodes (index, node->left, default_label, index_type);
6155 /* If left-hand subtree does nothing,
6157 emit_jump_if_reachable (default_label);
6159 /* Code branches here for the right-hand subtree. */
6160 expand_label (test_label);
6161 emit_case_nodes (index, node->right, default_label, index_type);
6165 else if (node->right != 0 && node->left == 0)
6167 /* Here we have a right child but no left so we issue conditional
6168 branch to default and process the right child.
6170 Omit the conditional branch to default if we it avoid only one
6171 right child; it costs too much space to save so little time. */
6173 if (node->right->right || node->right->left
6174 || !tree_int_cst_equal (node->right->low, node->right->high))
6176 if (!node_has_low_bound (node, index_type))
6178 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6181 LT, NULL_RTX, mode, unsignedp, 0,
6185 emit_case_nodes (index, node->right, default_label, index_type);
6188 /* We cannot process node->right normally
6189 since we haven't ruled out the numbers less than
6190 this node's value. So handle node->right explicitly. */
6191 do_jump_if_equal (index,
6192 expand_expr (node->right->low, NULL_RTX,
6194 label_rtx (node->right->code_label), unsignedp);
6197 else if (node->right == 0 && node->left != 0)
6199 /* Just one subtree, on the left. */
6201 #if 0 /* The following code and comment were formerly part
6202 of the condition here, but they didn't work
6203 and I don't understand what the idea was. -- rms. */
6204 /* If our "most probable entry" is less probable
6205 than the default label, emit a jump to
6206 the default label using condition codes
6207 already lying around. With no right branch,
6208 a branch-greater-than will get us to the default
6211 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
6214 if (node->left->left || node->left->right
6215 || !tree_int_cst_equal (node->left->low, node->left->high))
6217 if (!node_has_high_bound (node, index_type))
6219 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6222 GT, NULL_RTX, mode, unsignedp, 0,
6226 emit_case_nodes (index, node->left, default_label, index_type);
6229 /* We cannot process node->left normally
6230 since we haven't ruled out the numbers less than
6231 this node's value. So handle node->left explicitly. */
6232 do_jump_if_equal (index,
6233 expand_expr (node->left->low, NULL_RTX,
6235 label_rtx (node->left->code_label), unsignedp);
6240 /* Node is a range. These cases are very similar to those for a single
6241 value, except that we do not start by testing whether this node
6242 is the one to branch to. */
6244 if (node->right != 0 && node->left != 0)
6246 /* Node has subtrees on both sides.
6247 If the right-hand subtree is bounded,
6248 test for it first, since we can go straight there.
6249 Otherwise, we need to make a branch in the control structure,
6250 then handle the two subtrees. */
6251 tree test_label = 0;
6254 if (node_is_bounded (node->right, index_type))
6255 /* Right hand node is fully bounded so we can eliminate any
6256 testing and branch directly to the target code. */
6257 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6259 GT, NULL_RTX, mode, unsignedp, 0,
6260 label_rtx (node->right->code_label));
6263 /* Right hand node requires testing.
6264 Branch to a label where we will handle it later. */
6266 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6267 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6269 GT, NULL_RTX, mode, unsignedp, 0,
6270 label_rtx (test_label));
6273 /* Value belongs to this node or to the left-hand subtree. */
6275 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6277 GE, NULL_RTX, mode, unsignedp, 0,
6278 label_rtx (node->code_label));
6280 /* Handle the left-hand subtree. */
6281 emit_case_nodes (index, node->left, default_label, index_type);
6283 /* If right node had to be handled later, do that now. */
6287 /* If the left-hand subtree fell through,
6288 don't let it fall into the right-hand subtree. */
6289 emit_jump_if_reachable (default_label);
6291 expand_label (test_label);
6292 emit_case_nodes (index, node->right, default_label, index_type);
6296 else if (node->right != 0 && node->left == 0)
6298 /* Deal with values to the left of this node,
6299 if they are possible. */
6300 if (!node_has_low_bound (node, index_type))
6302 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6304 LT, NULL_RTX, mode, unsignedp, 0,
6308 /* Value belongs to this node or to the right-hand subtree. */
6310 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6312 LE, NULL_RTX, mode, unsignedp, 0,
6313 label_rtx (node->code_label));
6315 emit_case_nodes (index, node->right, default_label, index_type);
6318 else if (node->right == 0 && node->left != 0)
6320 /* Deal with values to the right of this node,
6321 if they are possible. */
6322 if (!node_has_high_bound (node, index_type))
6324 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6326 GT, NULL_RTX, mode, unsignedp, 0,
6330 /* Value belongs to this node or to the left-hand subtree. */
6332 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6334 GE, NULL_RTX, mode, unsignedp, 0,
6335 label_rtx (node->code_label));
6337 emit_case_nodes (index, node->left, default_label, index_type);
6342 /* Node has no children so we check low and high bounds to remove
6343 redundant tests. Only one of the bounds can exist,
6344 since otherwise this node is bounded--a case tested already. */
6346 if (!node_has_high_bound (node, index_type))
6348 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6350 GT, NULL_RTX, mode, unsignedp, 0,
6354 if (!node_has_low_bound (node, index_type))
6356 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6358 LT, NULL_RTX, mode, unsignedp, 0,
6362 emit_jump (label_rtx (node->code_label));