1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92, 93, 1994 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file handles the generation of rtl code from tree structure
22 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
23 It also creates the rtl expressions for parameters and auto variables
24 and has full responsibility for allocating stack slots.
26 The functions whose names start with `expand_' are called by the
27 parser to generate RTL instructions for various kinds of constructs.
29 Some control and binding constructs require calling several such
30 functions at different times. For example, a simple if-then
31 is expanded by calling `expand_start_cond' (with the condition-expression
32 as argument) before parsing the then-clause and calling `expand_end_cond'
33 after parsing the then-clause. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
55 #include "bc-typecd.h"
56 #include "bc-opcode.h"
60 #define obstack_chunk_alloc xmalloc
61 #define obstack_chunk_free free
62 struct obstack stmt_obstack;
64 /* Filename and line number of last line-number note,
65 whether we actually emitted it or not. */
69 /* Nonzero if within a ({...}) grouping, in which case we must
70 always compute a value for each expr-stmt in case it is the last one. */
72 int expr_stmts_for_value;
74 /* Each time we expand an expression-statement,
75 record the expr's type and its RTL value here. */
77 static tree last_expr_type;
78 static rtx last_expr_value;
80 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
81 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
82 This is used by the `remember_end_note' function to record the endpoint
83 of each generated block in its associated BLOCK node. */
85 static rtx last_block_end_note;
87 /* Number of binding contours started so far in this function. */
89 int block_start_count;
91 /* Nonzero if function being compiled needs to
92 return the address of where it has put a structure value. */
94 extern int current_function_returns_pcc_struct;
96 /* Label that will go on parm cleanup code, if any.
97 Jumping to this label runs cleanup code for parameters, if
98 such code must be run. Following this code is the logical return label. */
100 extern rtx cleanup_label;
102 /* Label that will go on function epilogue.
103 Jumping to this label serves as a "return" instruction
104 on machines which require execution of the epilogue on all returns. */
106 extern rtx return_label;
108 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
109 So we can mark them all live at the end of the function, if nonopt. */
110 extern rtx save_expr_regs;
112 /* Offset to end of allocated area of stack frame.
113 If stack grows down, this is the address of the last stack slot allocated.
114 If stack grows up, this is the address for the next slot. */
115 extern int frame_offset;
117 /* Label to jump back to for tail recursion, or 0 if we have
118 not yet needed one for this function. */
119 extern rtx tail_recursion_label;
121 /* Place after which to insert the tail_recursion_label if we need one. */
122 extern rtx tail_recursion_reentry;
124 /* Location at which to save the argument pointer if it will need to be
125 referenced. There are two cases where this is done: if nonlocal gotos
126 exist, or if vars whose is an offset from the argument pointer will be
127 needed by inner routines. */
129 extern rtx arg_pointer_save_area;
131 /* Chain of all RTL_EXPRs that have insns in them. */
132 extern tree rtl_expr_chain;
134 #if 0 /* Turned off because 0 seems to work just as well. */
135 /* Cleanup lists are required for binding levels regardless of whether
136 that binding level has cleanups or not. This node serves as the
137 cleanup list whenever an empty list is required. */
138 static tree empty_cleanup_list;
141 extern void (*interim_eh_hook) PROTO((tree));
143 /* Functions and data structures for expanding case statements. */
145 /* Case label structure, used to hold info on labels within case
146 statements. We handle "range" labels; for a single-value label
147 as in C, the high and low limits are the same.
149 A chain of case nodes is initially maintained via the RIGHT fields
150 in the nodes. Nodes with higher case values are later in the list.
152 Switch statements can be output in one of two forms. A branch table
153 is used if there are more than a few labels and the labels are dense
154 within the range between the smallest and largest case value. If a
155 branch table is used, no further manipulations are done with the case
158 The alternative to the use of a branch table is to generate a series
159 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
160 and PARENT fields to hold a binary tree. Initially the tree is
161 totally unbalanced, with everything on the right. We balance the tree
162 with nodes on the left having lower case values than the parent
163 and nodes on the right having higher values. We then output the tree
168 struct case_node *left; /* Left son in binary tree */
169 struct case_node *right; /* Right son in binary tree; also node chain */
170 struct case_node *parent; /* Parent of node in binary tree */
171 tree low; /* Lowest index value for this label */
172 tree high; /* Highest index value for this label */
173 tree code_label; /* Label to jump to when node matches */
176 typedef struct case_node case_node;
177 typedef struct case_node *case_node_ptr;
179 /* These are used by estimate_case_costs and balance_case_nodes. */
181 /* This must be a signed type, and non-ANSI compilers lack signed char. */
182 static short *cost_table;
183 static int use_cost_table;
185 /* Stack of control and binding constructs we are currently inside.
187 These constructs begin when you call `expand_start_WHATEVER'
188 and end when you call `expand_end_WHATEVER'. This stack records
189 info about how the construct began that tells the end-function
190 what to do. It also may provide information about the construct
191 to alter the behavior of other constructs within the body.
192 For example, they may affect the behavior of C `break' and `continue'.
194 Each construct gets one `struct nesting' object.
195 All of these objects are chained through the `all' field.
196 `nesting_stack' points to the first object (innermost construct).
197 The position of an entry on `nesting_stack' is in its `depth' field.
199 Each type of construct has its own individual stack.
200 For example, loops have `loop_stack'. Each object points to the
201 next object of the same type through the `next' field.
203 Some constructs are visible to `break' exit-statements and others
204 are not. Which constructs are visible depends on the language.
205 Therefore, the data structure allows each construct to be visible
206 or not, according to the args given when the construct is started.
207 The construct is visible if the `exit_label' field is non-null.
208 In that case, the value should be a CODE_LABEL rtx. */
213 struct nesting *next;
218 /* For conds (if-then and if-then-else statements). */
221 /* Label for the end of the if construct.
222 There is none if EXITFLAG was not set
223 and no `else' has been seen yet. */
225 /* Label for the end of this alternative.
226 This may be the end of the if or the next else/elseif. */
232 /* Label at the top of the loop; place to loop back to. */
234 /* Label at the end of the whole construct. */
236 /* Label before a jump that branches to the end of the whole
237 construct. This is where destructors go if any. */
239 /* Label for `continue' statement to jump to;
240 this is in front of the stepper of the loop. */
243 /* For variable binding contours. */
246 /* Sequence number of this binding contour within the function,
247 in order of entry. */
248 int block_start_count;
249 /* Nonzero => value to restore stack to on exit. Complemented by
250 bc_stack_level (see below) when generating bytecodes. */
252 /* The NOTE that starts this contour.
253 Used by expand_goto to check whether the destination
254 is within each contour or not. */
256 /* Innermost containing binding contour that has a stack level. */
257 struct nesting *innermost_stack_block;
258 /* List of cleanups to be run on exit from this contour.
259 This is a list of expressions to be evaluated.
260 The TREE_PURPOSE of each link is the ..._DECL node
261 which the cleanup pertains to. */
263 /* List of cleanup-lists of blocks containing this block,
264 as they were at the locus where this block appears.
265 There is an element for each containing block,
266 ordered innermost containing block first.
267 The tail of this list can be 0 (was empty_cleanup_list),
268 if all remaining elements would be empty lists.
269 The element's TREE_VALUE is the cleanup-list of that block,
270 which may be null. */
272 /* Chain of labels defined inside this binding contour.
273 For contours that have stack levels or cleanups. */
274 struct label_chain *label_chain;
275 /* Number of function calls seen, as of start of this block. */
276 int function_call_count;
277 /* Bytecode specific: stack level to restore stack to on exit. */
280 /* For switch (C) or case (Pascal) statements,
281 and also for dummies (see `expand_start_case_dummy'). */
284 /* The insn after which the case dispatch should finally
285 be emitted. Zero for a dummy. */
287 /* For bytecodes, the case table is in-lined right in the code.
288 A label is needed for skipping over this block. It is only
289 used when generating bytecodes. */
291 /* A list of case labels, kept in ascending order by value
292 as the list is built.
293 During expand_end_case, this list may be rearranged into a
294 nearly balanced binary tree. */
295 struct case_node *case_list;
296 /* Label to jump to if no case matches. */
298 /* The expression to be dispatched on. */
300 /* Type that INDEX_EXPR should be converted to. */
302 /* Number of range exprs in case statement. */
304 /* Name of this kind of statement, for warnings. */
306 /* Nonzero if a case label has been seen in this case stmt. */
312 /* Chain of all pending binding contours. */
313 struct nesting *block_stack;
315 /* If any new stacks are added here, add them to POPSTACKS too. */
317 /* Chain of all pending binding contours that restore stack levels
319 struct nesting *stack_block_stack;
321 /* Chain of all pending conditional statements. */
322 struct nesting *cond_stack;
324 /* Chain of all pending loops. */
325 struct nesting *loop_stack;
327 /* Chain of all pending case or switch statements. */
328 struct nesting *case_stack;
330 /* Separate chain including all of the above,
331 chained through the `all' field. */
332 struct nesting *nesting_stack;
334 /* Number of entries on nesting_stack now. */
337 /* Allocate and return a new `struct nesting'. */
339 #define ALLOC_NESTING() \
340 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
342 /* Pop the nesting stack element by element until we pop off
343 the element which is at the top of STACK.
344 Update all the other stacks, popping off elements from them
345 as we pop them from nesting_stack. */
347 #define POPSTACK(STACK) \
348 do { struct nesting *target = STACK; \
349 struct nesting *this; \
350 do { this = nesting_stack; \
351 if (loop_stack == this) \
352 loop_stack = loop_stack->next; \
353 if (cond_stack == this) \
354 cond_stack = cond_stack->next; \
355 if (block_stack == this) \
356 block_stack = block_stack->next; \
357 if (stack_block_stack == this) \
358 stack_block_stack = stack_block_stack->next; \
359 if (case_stack == this) \
360 case_stack = case_stack->next; \
361 nesting_depth = nesting_stack->depth - 1; \
362 nesting_stack = this->all; \
363 obstack_free (&stmt_obstack, this); } \
364 while (this != target); } while (0)
366 /* In some cases it is impossible to generate code for a forward goto
367 until the label definition is seen. This happens when it may be necessary
368 for the goto to reset the stack pointer: we don't yet know how to do that.
369 So expand_goto puts an entry on this fixup list.
370 Each time a binding contour that resets the stack is exited,
372 If the target label has now been defined, we can insert the proper code. */
376 /* Points to following fixup. */
377 struct goto_fixup *next;
378 /* Points to the insn before the jump insn.
379 If more code must be inserted, it goes after this insn. */
381 /* The LABEL_DECL that this jump is jumping to, or 0
382 for break, continue or return. */
384 /* The BLOCK for the place where this goto was found. */
386 /* The CODE_LABEL rtx that this is jumping to. */
388 /* Number of binding contours started in current function
389 before the label reference. */
390 int block_start_count;
391 /* The outermost stack level that should be restored for this jump.
392 Each time a binding contour that resets the stack is exited,
393 if the target label is *not* yet defined, this slot is updated. */
395 /* List of lists of cleanup expressions to be run by this goto.
396 There is one element for each block that this goto is within.
397 The tail of this list can be 0 (was empty_cleanup_list),
398 if all remaining elements would be empty.
399 The TREE_VALUE contains the cleanup list of that block as of the
400 time this goto was seen.
401 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
402 tree cleanup_list_list;
404 /* Bytecode specific members follow */
406 /* The label that this jump is jumping to, or 0 for break, continue
408 struct bc_label *bc_target;
410 /* The label we use for the fixup patch */
411 struct bc_label *label;
413 /* True (non-0) if fixup has been handled */
416 /* Like stack_level above, except refers to the interpreter stack */
420 static struct goto_fixup *goto_fixup_chain;
422 /* Within any binding contour that must restore a stack level,
423 all labels are recorded with a chain of these structures. */
427 /* Points to following fixup. */
428 struct label_chain *next;
431 static void expand_goto_internal PROTO((tree, rtx, rtx));
432 static void bc_expand_goto_internal PROTO((enum bytecode_opcode,
433 struct bc_label *, tree));
434 static int expand_fixup PROTO((tree, rtx, rtx));
435 static void bc_expand_fixup PROTO((enum bytecode_opcode,
436 struct bc_label *, int));
437 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
439 static void bc_fixup_gotos PROTO((struct nesting *, int, tree,
441 static int warn_if_unused_value PROTO((tree));
442 static void bc_expand_start_cond PROTO((tree, int));
443 static void bc_expand_end_cond PROTO((void));
444 static void bc_expand_start_else PROTO((void));
445 static void bc_expand_end_loop PROTO((void));
446 static void bc_expand_end_bindings PROTO((tree, int, int));
447 static void bc_expand_decl PROTO((tree, tree));
448 static void bc_expand_variable_local_init PROTO((tree));
449 static void bc_expand_decl_init PROTO((tree));
450 static void expand_null_return_1 PROTO((rtx, int));
451 static int tail_recursion_args PROTO((tree, tree));
452 static void expand_cleanups PROTO((tree, tree, int));
453 static void bc_expand_start_case PROTO((struct nesting *, tree,
455 static int bc_pushcase PROTO((tree, tree));
456 static void bc_check_for_full_enumeration_handling PROTO((tree));
457 static void bc_expand_end_case PROTO((tree));
458 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
459 static int estimate_case_costs PROTO((case_node_ptr));
460 static void group_case_nodes PROTO((case_node_ptr));
461 static void balance_case_nodes PROTO((case_node_ptr *,
463 static int node_has_low_bound PROTO((case_node_ptr, tree));
464 static int node_has_high_bound PROTO((case_node_ptr, tree));
465 static int node_is_bounded PROTO((case_node_ptr, tree));
466 static void emit_jump_if_reachable PROTO((rtx));
467 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
469 int bc_expand_exit_loop_if_false ();
470 void bc_expand_start_cond ();
471 void bc_expand_end_cond ();
472 void bc_expand_start_else ();
473 void bc_expand_end_bindings ();
474 void bc_expand_start_case ();
475 void bc_check_for_full_enumeration_handling ();
476 void bc_expand_end_case ();
477 void bc_expand_decl ();
479 extern rtx bc_allocate_local ();
480 extern rtx bc_allocate_variable_array ();
485 gcc_obstack_init (&stmt_obstack);
487 empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE);
492 init_stmt_for_function ()
494 /* We are not currently within any block, conditional, loop or case. */
496 stack_block_stack = 0;
503 block_start_count = 0;
505 /* No gotos have been expanded yet. */
506 goto_fixup_chain = 0;
508 /* We are not processing a ({...}) grouping. */
509 expr_stmts_for_value = 0;
517 p->block_stack = block_stack;
518 p->stack_block_stack = stack_block_stack;
519 p->cond_stack = cond_stack;
520 p->loop_stack = loop_stack;
521 p->case_stack = case_stack;
522 p->nesting_stack = nesting_stack;
523 p->nesting_depth = nesting_depth;
524 p->block_start_count = block_start_count;
525 p->last_expr_type = last_expr_type;
526 p->last_expr_value = last_expr_value;
527 p->expr_stmts_for_value = expr_stmts_for_value;
528 p->emit_filename = emit_filename;
529 p->emit_lineno = emit_lineno;
530 p->goto_fixup_chain = goto_fixup_chain;
534 restore_stmt_status (p)
537 block_stack = p->block_stack;
538 stack_block_stack = p->stack_block_stack;
539 cond_stack = p->cond_stack;
540 loop_stack = p->loop_stack;
541 case_stack = p->case_stack;
542 nesting_stack = p->nesting_stack;
543 nesting_depth = p->nesting_depth;
544 block_start_count = p->block_start_count;
545 last_expr_type = p->last_expr_type;
546 last_expr_value = p->last_expr_value;
547 expr_stmts_for_value = p->expr_stmts_for_value;
548 emit_filename = p->emit_filename;
549 emit_lineno = p->emit_lineno;
550 goto_fixup_chain = p->goto_fixup_chain;
553 /* Emit a no-op instruction. */
560 if (!output_bytecode)
562 last_insn = get_last_insn ();
564 && (GET_CODE (last_insn) == CODE_LABEL
565 || prev_real_insn (last_insn) == 0))
566 emit_insn (gen_nop ());
570 /* Return the rtx-label that corresponds to a LABEL_DECL,
571 creating it if necessary. */
577 if (TREE_CODE (label) != LABEL_DECL)
580 if (DECL_RTL (label))
581 return DECL_RTL (label);
583 return DECL_RTL (label) = gen_label_rtx ();
586 /* Add an unconditional jump to LABEL as the next sequential instruction. */
592 do_pending_stack_adjust ();
593 emit_jump_insn (gen_jump (label));
597 /* Emit code to jump to the address
598 specified by the pointer expression EXP. */
601 expand_computed_goto (exp)
606 bc_expand_expr (exp);
607 bc_emit_instruction (jumpP);
611 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
613 emit_indirect_jump (x);
617 /* Handle goto statements and the labels that they can go to. */
619 /* Specify the location in the RTL code of a label LABEL,
620 which is a LABEL_DECL tree node.
622 This is used for the kind of label that the user can jump to with a
623 goto statement, and for alternatives of a switch or case statement.
624 RTL labels generated for loops and conditionals don't go through here;
625 they are generated directly at the RTL level, by other functions below.
627 Note that this has nothing to do with defining label *names*.
628 Languages vary in how they do that and what that even means. */
634 struct label_chain *p;
638 if (! DECL_RTL (label))
639 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
640 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
641 error ("multiply defined label");
645 do_pending_stack_adjust ();
646 emit_label (label_rtx (label));
647 if (DECL_NAME (label))
648 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
650 if (stack_block_stack != 0)
652 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
653 p->next = stack_block_stack->data.block.label_chain;
654 stack_block_stack->data.block.label_chain = p;
659 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
660 from nested functions. */
663 declare_nonlocal_label (label)
666 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
667 LABEL_PRESERVE_P (label_rtx (label)) = 1;
668 if (nonlocal_goto_handler_slot == 0)
670 nonlocal_goto_handler_slot
671 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
672 emit_stack_save (SAVE_NONLOCAL,
673 &nonlocal_goto_stack_level,
674 PREV_INSN (tail_recursion_reentry));
678 /* Generate RTL code for a `goto' statement with target label LABEL.
679 LABEL should be a LABEL_DECL tree node that was or will later be
680 defined with `expand_label'. */
690 expand_goto_internal (label, label_rtx (label), NULL_RTX);
694 /* Check for a nonlocal goto to a containing function. */
695 context = decl_function_context (label);
696 if (context != 0 && context != current_function_decl)
698 struct function *p = find_function_data (context);
699 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
702 p->has_nonlocal_label = 1;
703 current_function_has_nonlocal_goto = 1;
704 LABEL_REF_NONLOCAL_P (label_ref) = 1;
706 /* Copy the rtl for the slots so that they won't be shared in
707 case the virtual stack vars register gets instantiated differently
708 in the parent than in the child. */
710 #if HAVE_nonlocal_goto
711 if (HAVE_nonlocal_goto)
712 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
713 copy_rtx (p->nonlocal_goto_handler_slot),
714 copy_rtx (p->nonlocal_goto_stack_level),
721 /* Restore frame pointer for containing function.
722 This sets the actual hard register used for the frame pointer
723 to the location of the function's incoming static chain info.
724 The non-local goto handler will then adjust it to contain the
725 proper value and reload the argument pointer, if needed. */
726 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
728 /* We have now loaded the frame pointer hardware register with
729 the address of that corresponds to the start of the virtual
730 stack vars. So replace virtual_stack_vars_rtx in all
731 addresses we use with stack_pointer_rtx. */
733 /* Get addr of containing function's current nonlocal goto handler,
734 which will do any cleanups and then jump to the label. */
735 addr = copy_rtx (p->nonlocal_goto_handler_slot);
736 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
737 hard_frame_pointer_rtx));
739 /* Restore the stack pointer. Note this uses fp just restored. */
740 addr = p->nonlocal_goto_stack_level;
742 addr = replace_rtx (copy_rtx (addr),
743 virtual_stack_vars_rtx,
744 hard_frame_pointer_rtx);
746 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
748 /* Put in the static chain register the nonlocal label address. */
749 emit_move_insn (static_chain_rtx, label_ref);
750 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
752 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
753 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
754 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
755 emit_indirect_jump (temp);
759 expand_goto_internal (label, label_rtx (label), NULL_RTX);
762 /* Generate RTL code for a `goto' statement with target label BODY.
763 LABEL should be a LABEL_REF.
764 LAST_INSN, if non-0, is the rtx we should consider as the last
765 insn emitted (for the purposes of cleaning up a return). */
768 expand_goto_internal (body, label, last_insn)
773 struct nesting *block;
776 /* NOTICE! If a bytecode instruction other than `jump' is needed,
777 then the caller has to call bc_expand_goto_internal()
778 directly. This is rather an exceptional case, and there aren't
779 that many places where this is necessary. */
782 expand_goto_internal (body, label, last_insn);
786 if (GET_CODE (label) != CODE_LABEL)
789 /* If label has already been defined, we can tell now
790 whether and how we must alter the stack level. */
792 if (PREV_INSN (label) != 0)
794 /* Find the innermost pending block that contains the label.
795 (Check containment by comparing insn-uids.)
796 Then restore the outermost stack level within that block,
797 and do cleanups of all blocks contained in it. */
798 for (block = block_stack; block; block = block->next)
800 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
802 if (block->data.block.stack_level != 0)
803 stack_level = block->data.block.stack_level;
804 /* Execute the cleanups for blocks we are exiting. */
805 if (block->data.block.cleanups != 0)
807 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1);
808 do_pending_stack_adjust ();
814 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
815 the stack pointer. This one should be deleted as dead by flow. */
816 clear_pending_stack_adjust ();
817 do_pending_stack_adjust ();
818 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
821 if (body != 0 && DECL_TOO_LATE (body))
822 error ("jump to `%s' invalidly jumps into binding contour",
823 IDENTIFIER_POINTER (DECL_NAME (body)));
825 /* Label not yet defined: may need to put this goto
826 on the fixup list. */
827 else if (! expand_fixup (body, label, last_insn))
829 /* No fixup needed. Record that the label is the target
830 of at least one goto that has no fixup. */
832 TREE_ADDRESSABLE (body) = 1;
838 /* Generate a jump with OPCODE to the given bytecode LABEL which is
839 found within BODY. */
842 bc_expand_goto_internal (opcode, label, body)
843 enum bytecode_opcode opcode;
844 struct bc_label *label;
847 struct nesting *block;
848 int stack_level = -1;
850 /* If the label is defined, adjust the stack as necessary.
851 If it's not defined, we have to push the reference on the
857 /* Find the innermost pending block that contains the label.
858 (Check containment by comparing bytecode uids.) Then restore the
859 outermost stack level within that block. */
861 for (block = block_stack; block; block = block->next)
863 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
865 if (block->data.block.bc_stack_level)
866 stack_level = block->data.block.bc_stack_level;
868 /* Execute the cleanups for blocks we are exiting. */
869 if (block->data.block.cleanups != 0)
871 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1);
872 do_pending_stack_adjust ();
876 /* Restore the stack level. If we need to adjust the stack, we
877 must do so after the jump, since the jump may depend on
878 what's on the stack. Thus, any stack-modifying conditional
879 jumps (these are the only ones that rely on what's on the
880 stack) go into the fixup list. */
883 && stack_depth != stack_level
886 bc_expand_fixup (opcode, label, stack_level);
889 if (stack_level >= 0)
890 bc_adjust_stack (stack_depth - stack_level);
892 if (body && DECL_BIT_FIELD (body))
893 error ("jump to `%s' invalidly jumps into binding contour",
894 IDENTIFIER_POINTER (DECL_NAME (body)));
896 /* Emit immediate jump */
897 bc_emit_bytecode (opcode);
898 bc_emit_bytecode_labelref (label);
900 #ifdef DEBUG_PRINT_CODE
901 fputc ('\n', stderr);
906 /* Put goto in the fixup list */
907 bc_expand_fixup (opcode, label, stack_level);
910 /* Generate if necessary a fixup for a goto
911 whose target label in tree structure (if any) is TREE_LABEL
912 and whose target in rtl is RTL_LABEL.
914 If LAST_INSN is nonzero, we pretend that the jump appears
915 after insn LAST_INSN instead of at the current point in the insn stream.
917 The fixup will be used later to insert insns just before the goto.
918 Those insns will restore the stack level as appropriate for the
919 target label, and will (in the case of C++) also invoke any object
920 destructors which have to be invoked when we exit the scopes which
921 are exited by the goto.
923 Value is nonzero if a fixup is made. */
926 expand_fixup (tree_label, rtl_label, last_insn)
931 struct nesting *block, *end_block;
933 /* See if we can recognize which block the label will be output in.
934 This is possible in some very common cases.
935 If we succeed, set END_BLOCK to that block.
936 Otherwise, set it to 0. */
939 && (rtl_label == cond_stack->data.cond.endif_label
940 || rtl_label == cond_stack->data.cond.next_label))
941 end_block = cond_stack;
942 /* If we are in a loop, recognize certain labels which
943 are likely targets. This reduces the number of fixups
944 we need to create. */
946 && (rtl_label == loop_stack->data.loop.start_label
947 || rtl_label == loop_stack->data.loop.end_label
948 || rtl_label == loop_stack->data.loop.continue_label))
949 end_block = loop_stack;
953 /* Now set END_BLOCK to the binding level to which we will return. */
957 struct nesting *next_block = end_block->all;
960 /* First see if the END_BLOCK is inside the innermost binding level.
961 If so, then no cleanups or stack levels are relevant. */
962 while (next_block && next_block != block)
963 next_block = next_block->all;
968 /* Otherwise, set END_BLOCK to the innermost binding level
969 which is outside the relevant control-structure nesting. */
970 next_block = block_stack->next;
971 for (block = block_stack; block != end_block; block = block->all)
972 if (block == next_block)
973 next_block = next_block->next;
974 end_block = next_block;
977 /* Does any containing block have a stack level or cleanups?
978 If not, no fixup is needed, and that is the normal case
979 (the only case, for standard C). */
980 for (block = block_stack; block != end_block; block = block->next)
981 if (block->data.block.stack_level != 0
982 || block->data.block.cleanups != 0)
985 if (block != end_block)
987 /* Ok, a fixup is needed. Add a fixup to the list of such. */
988 struct goto_fixup *fixup
989 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
990 /* In case an old stack level is restored, make sure that comes
991 after any pending stack adjust. */
992 /* ?? If the fixup isn't to come at the present position,
993 doing the stack adjust here isn't useful. Doing it with our
994 settings at that location isn't useful either. Let's hope
997 do_pending_stack_adjust ();
998 fixup->target = tree_label;
999 fixup->target_rtl = rtl_label;
1001 /* Create a BLOCK node and a corresponding matched set of
1002 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1003 this point. The notes will encapsulate any and all fixup
1004 code which we might later insert at this point in the insn
1005 stream. Also, the BLOCK node will be the parent (i.e. the
1006 `SUPERBLOCK') of any other BLOCK nodes which we might create
1007 later on when we are expanding the fixup code. */
1010 register rtx original_before_jump
1011 = last_insn ? last_insn : get_last_insn ();
1015 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1016 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1017 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1019 emit_insns_after (fixup->before_jump, original_before_jump);
1022 fixup->block_start_count = block_start_count;
1023 fixup->stack_level = 0;
1024 fixup->cleanup_list_list
1025 = (((block->data.block.outer_cleanups
1027 && block->data.block.outer_cleanups != empty_cleanup_list
1030 || block->data.block.cleanups)
1031 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1032 block->data.block.outer_cleanups)
1034 fixup->next = goto_fixup_chain;
1035 goto_fixup_chain = fixup;
1042 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1043 Make the fixup restore the stack level to STACK_LEVEL. */
1046 bc_expand_fixup (opcode, label, stack_level)
1047 enum bytecode_opcode opcode;
1048 struct bc_label *label;
1051 struct goto_fixup *fixup
1052 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1054 fixup->label = bc_get_bytecode_label ();
1055 fixup->bc_target = label;
1056 fixup->bc_stack_level = stack_level;
1057 fixup->bc_handled = FALSE;
1059 fixup->next = goto_fixup_chain;
1060 goto_fixup_chain = fixup;
1062 /* Insert a jump to the fixup code */
1063 bc_emit_bytecode (opcode);
1064 bc_emit_bytecode_labelref (fixup->label);
1066 #ifdef DEBUG_PRINT_CODE
1067 fputc ('\n', stderr);
1071 /* Expand any needed fixups in the outputmost binding level of the
1072 function. FIRST_INSN is the first insn in the function. */
1075 expand_fixups (first_insn)
1078 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1081 /* When exiting a binding contour, process all pending gotos requiring fixups.
1082 THISBLOCK is the structure that describes the block being exited.
1083 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1084 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1085 FIRST_INSN is the insn that began this contour.
1087 Gotos that jump out of this contour must restore the
1088 stack level and do the cleanups before actually jumping.
1090 DONT_JUMP_IN nonzero means report error there is a jump into this
1091 contour from before the beginning of the contour.
1092 This is also done if STACK_LEVEL is nonzero. */
1095 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1096 struct nesting *thisblock;
1102 register struct goto_fixup *f, *prev;
1104 if (output_bytecode)
1106 /* ??? The second arg is the bc stack level, which is not the same
1107 as STACK_LEVEL. I have no idea what should go here, so I'll
1109 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1113 /* F is the fixup we are considering; PREV is the previous one. */
1114 /* We run this loop in two passes so that cleanups of exited blocks
1115 are run first, and blocks that are exited are marked so
1118 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1120 /* Test for a fixup that is inactive because it is already handled. */
1121 if (f->before_jump == 0)
1123 /* Delete inactive fixup from the chain, if that is easy to do. */
1125 prev->next = f->next;
1127 /* Has this fixup's target label been defined?
1128 If so, we can finalize it. */
1129 else if (PREV_INSN (f->target_rtl) != 0)
1131 register rtx cleanup_insns;
1133 /* Get the first non-label after the label
1134 this goto jumps to. If that's before this scope begins,
1135 we don't have a jump into the scope. */
1136 rtx after_label = f->target_rtl;
1137 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1138 after_label = NEXT_INSN (after_label);
1140 /* If this fixup jumped into this contour from before the beginning
1141 of this contour, report an error. */
1142 /* ??? Bug: this does not detect jumping in through intermediate
1143 blocks that have stack levels or cleanups.
1144 It detects only a problem with the innermost block
1145 around the label. */
1147 && (dont_jump_in || stack_level || cleanup_list)
1148 /* If AFTER_LABEL is 0, it means the jump goes to the end
1149 of the rtl, which means it jumps into this scope. */
1150 && (after_label == 0
1151 || INSN_UID (first_insn) < INSN_UID (after_label))
1152 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1153 && ! DECL_REGISTER (f->target))
1155 error_with_decl (f->target,
1156 "label `%s' used before containing binding contour");
1157 /* Prevent multiple errors for one label. */
1158 DECL_REGISTER (f->target) = 1;
1161 /* We will expand the cleanups into a sequence of their own and
1162 then later on we will attach this new sequence to the insn
1163 stream just ahead of the actual jump insn. */
1167 /* Temporarily restore the lexical context where we will
1168 logically be inserting the fixup code. We do this for the
1169 sake of getting the debugging information right. */
1172 set_block (f->context);
1174 /* Expand the cleanups for blocks this jump exits. */
1175 if (f->cleanup_list_list)
1178 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1179 /* Marked elements correspond to blocks that have been closed.
1180 Do their cleanups. */
1181 if (TREE_ADDRESSABLE (lists)
1182 && TREE_VALUE (lists) != 0)
1184 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1);
1185 /* Pop any pushes done in the cleanups,
1186 in case function is about to return. */
1187 do_pending_stack_adjust ();
1191 /* Restore stack level for the biggest contour that this
1192 jump jumps out of. */
1194 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1196 /* Finish up the sequence containing the insns which implement the
1197 necessary cleanups, and then attach that whole sequence to the
1198 insn stream just ahead of the actual jump insn. Attaching it
1199 at that point insures that any cleanups which are in fact
1200 implicit C++ object destructions (which must be executed upon
1201 leaving the block) appear (to the debugger) to be taking place
1202 in an area of the generated code where the object(s) being
1203 destructed are still "in scope". */
1205 cleanup_insns = get_insns ();
1209 emit_insns_after (cleanup_insns, f->before_jump);
1216 /* Mark the cleanups of exited blocks so that they are executed
1217 by the code above. */
1218 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1219 if (f->before_jump != 0
1220 && PREV_INSN (f->target_rtl) == 0
1221 /* Label has still not appeared. If we are exiting a block with
1222 a stack level to restore, that started before the fixup,
1223 mark this stack level as needing restoration
1224 when the fixup is later finalized.
1225 Also mark the cleanup_list_list element for F
1226 that corresponds to this block, so that ultimately
1227 this block's cleanups will be executed by the code above. */
1229 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared,
1230 it means the label is undefined. That's erroneous, but possible. */
1231 && (thisblock->data.block.block_start_count
1232 <= f->block_start_count))
1234 tree lists = f->cleanup_list_list;
1235 for (; lists; lists = TREE_CHAIN (lists))
1236 /* If the following elt. corresponds to our containing block
1237 then the elt. must be for this block. */
1238 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1239 TREE_ADDRESSABLE (lists) = 1;
1242 f->stack_level = stack_level;
1247 /* When exiting a binding contour, process all pending gotos requiring fixups.
1248 Note: STACK_DEPTH is not altered.
1250 The arguments are currently not used in the bytecode compiler, but we may
1251 need them one day for languages other than C.
1253 THISBLOCK is the structure that describes the block being exited.
1254 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1255 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1256 FIRST_INSN is the insn that began this contour.
1258 Gotos that jump out of this contour must restore the
1259 stack level and do the cleanups before actually jumping.
1261 DONT_JUMP_IN nonzero means report error there is a jump into this
1262 contour from before the beginning of the contour.
1263 This is also done if STACK_LEVEL is nonzero. */
1266 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1267 struct nesting *thisblock;
1273 register struct goto_fixup *f, *prev;
1274 int saved_stack_depth;
1276 /* F is the fixup we are considering; PREV is the previous one. */
1278 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1280 /* Test for a fixup that is inactive because it is already handled. */
1281 if (f->before_jump == 0)
1283 /* Delete inactive fixup from the chain, if that is easy to do. */
1285 prev->next = f->next;
1288 /* Emit code to restore the stack and continue */
1289 bc_emit_bytecode_labeldef (f->label);
1291 /* Save stack_depth across call, since bc_adjust_stack () will alter
1292 the perceived stack depth via the instructions generated. */
1294 if (f->bc_stack_level >= 0)
1296 saved_stack_depth = stack_depth;
1297 bc_adjust_stack (stack_depth - f->bc_stack_level);
1298 stack_depth = saved_stack_depth;
1301 bc_emit_bytecode (jump);
1302 bc_emit_bytecode_labelref (f->bc_target);
1304 #ifdef DEBUG_PRINT_CODE
1305 fputc ('\n', stderr);
1309 goto_fixup_chain = NULL;
1312 /* Generate RTL for an asm statement (explicit assembler code).
1313 BODY is a STRING_CST node containing the assembler code text,
1314 or an ADDR_EXPR containing a STRING_CST. */
1320 if (output_bytecode)
1322 error ("`asm' is illegal when generating bytecode");
1326 if (TREE_CODE (body) == ADDR_EXPR)
1327 body = TREE_OPERAND (body, 0);
1329 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1330 TREE_STRING_POINTER (body)));
1334 /* Generate RTL for an asm statement with arguments.
1335 STRING is the instruction template.
1336 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1337 Each output or input has an expression in the TREE_VALUE and
1338 a constraint-string in the TREE_PURPOSE.
1339 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1340 that is clobbered by this insn.
1342 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1343 Some elements of OUTPUTS may be replaced with trees representing temporary
1344 values. The caller should copy those temporary values to the originally
1347 VOL nonzero means the insn is volatile; don't optimize it. */
1350 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1351 tree string, outputs, inputs, clobbers;
1356 rtvec argvec, constraints;
1358 int ninputs = list_length (inputs);
1359 int noutputs = list_length (outputs);
1363 /* Vector of RTX's of evaluated output operands. */
1364 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1365 /* The insn we have emitted. */
1368 if (output_bytecode)
1370 error ("`asm' is illegal when generating bytecode");
1374 /* Count the number of meaningful clobbered registers, ignoring what
1375 we would ignore later. */
1377 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1379 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1380 i = decode_reg_name (regname);
1381 if (i >= 0 || i == -4)
1384 error ("unknown register name `%s' in `asm'", regname);
1389 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1391 tree val = TREE_VALUE (tail);
1396 /* If there's an erroneous arg, emit no insn. */
1397 if (TREE_TYPE (val) == error_mark_node)
1400 /* Make sure constraint has `=' and does not have `+'. */
1403 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1405 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1407 error ("output operand constraint contains `+'");
1410 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=')
1415 error ("output operand constraint lacks `='");
1419 /* If an output operand is not a variable or indirect ref,
1421 create a SAVE_EXPR which is a pseudo-reg
1422 to act as an intermediate temporary.
1423 Make the asm insn write into that, then copy it to
1424 the real output operand. */
1426 while (TREE_CODE (val) == COMPONENT_REF
1427 || TREE_CODE (val) == ARRAY_REF)
1428 val = TREE_OPERAND (val, 0);
1430 if (TREE_CODE (val) != VAR_DECL
1431 && TREE_CODE (val) != PARM_DECL
1432 && TREE_CODE (val) != INDIRECT_REF)
1434 TREE_VALUE (tail) = save_expr (TREE_VALUE (tail));
1435 /* If it's a constant, print error now so don't crash later. */
1436 if (TREE_CODE (TREE_VALUE (tail)) != SAVE_EXPR)
1438 error ("invalid output in `asm'");
1443 output_rtx[i] = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1446 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1448 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1452 /* Make vectors for the expression-rtx and constraint strings. */
1454 argvec = rtvec_alloc (ninputs);
1455 constraints = rtvec_alloc (ninputs);
1457 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1458 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1460 MEM_VOLATILE_P (body) = vol;
1462 /* Eval the inputs and put them into ARGVEC.
1463 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1466 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1470 /* If there's an erroneous arg, emit no insn,
1471 because the ASM_INPUT would get VOIDmode
1472 and that could cause a crash in reload. */
1473 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1475 if (TREE_PURPOSE (tail) == NULL_TREE)
1477 error ("hard register `%s' listed as input operand to `asm'",
1478 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1482 /* Make sure constraint has neither `=' nor `+'. */
1484 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1485 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '='
1486 || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1488 error ("input operand constraint contains `%c'",
1489 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1493 XVECEXP (body, 3, i) /* argvec */
1494 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1495 if (CONSTANT_P (XVECEXP (body, 3, i))
1496 && ! general_operand (XVECEXP (body, 3, i),
1497 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1498 XVECEXP (body, 3, i)
1499 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1500 XVECEXP (body, 3, i));
1501 XVECEXP (body, 4, i) /* constraints */
1502 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1503 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1507 /* Protect all the operands from the queue,
1508 now that they have all been evaluated. */
1510 for (i = 0; i < ninputs; i++)
1511 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1513 for (i = 0; i < noutputs; i++)
1514 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1516 /* Now, for each output, construct an rtx
1517 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1518 ARGVEC CONSTRAINTS))
1519 If there is more than one, put them inside a PARALLEL. */
1521 if (noutputs == 1 && nclobbers == 0)
1523 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1524 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1526 else if (noutputs == 0 && nclobbers == 0)
1528 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1529 insn = emit_insn (body);
1535 if (num == 0) num = 1;
1536 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1538 /* For each output operand, store a SET. */
1540 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1542 XVECEXP (body, 0, i)
1543 = gen_rtx (SET, VOIDmode,
1545 gen_rtx (ASM_OPERANDS, VOIDmode,
1546 TREE_STRING_POINTER (string),
1547 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1548 i, argvec, constraints,
1550 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1553 /* If there are no outputs (but there are some clobbers)
1554 store the bare ASM_OPERANDS into the PARALLEL. */
1557 XVECEXP (body, 0, i++) = obody;
1559 /* Store (clobber REG) for each clobbered register specified. */
1561 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1563 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1564 int j = decode_reg_name (regname);
1568 if (j == -3) /* `cc', which is not a register */
1571 if (j == -4) /* `memory', don't cache memory across asm */
1573 XVECEXP (body, 0, i++)
1574 = gen_rtx (CLOBBER, VOIDmode,
1575 gen_rtx (MEM, BLKmode,
1576 gen_rtx (SCRATCH, VOIDmode, 0)));
1580 /* Ignore unknown register, error already signalled. */
1583 /* Use QImode since that's guaranteed to clobber just one reg. */
1584 XVECEXP (body, 0, i++)
1585 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1588 insn = emit_insn (body);
1594 /* Generate RTL to evaluate the expression EXP
1595 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1598 expand_expr_stmt (exp)
1601 if (output_bytecode)
1603 int org_stack_depth = stack_depth;
1605 bc_expand_expr (exp);
1607 /* Restore stack depth */
1608 if (stack_depth < org_stack_depth)
1611 bc_emit_instruction (drop);
1613 last_expr_type = TREE_TYPE (exp);
1617 /* If -W, warn about statements with no side effects,
1618 except for an explicit cast to void (e.g. for assert()), and
1619 except inside a ({...}) where they may be useful. */
1620 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1622 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1623 && !(TREE_CODE (exp) == CONVERT_EXPR
1624 && TREE_TYPE (exp) == void_type_node))
1625 warning_with_file_and_line (emit_filename, emit_lineno,
1626 "statement with no effect");
1627 else if (warn_unused)
1628 warn_if_unused_value (exp);
1631 /* If EXP is of function type and we are expanding statements for
1632 value, convert it to pointer-to-function. */
1633 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1634 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1636 last_expr_type = TREE_TYPE (exp);
1637 if (! flag_syntax_only)
1638 last_expr_value = expand_expr (exp,
1639 (expr_stmts_for_value
1640 ? NULL_RTX : const0_rtx),
1643 /* If all we do is reference a volatile value in memory,
1644 copy it to a register to be sure it is actually touched. */
1645 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1646 && TREE_THIS_VOLATILE (exp))
1648 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1650 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1651 copy_to_reg (last_expr_value);
1654 rtx lab = gen_label_rtx ();
1656 /* Compare the value with itself to reference it. */
1657 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1658 expand_expr (TYPE_SIZE (last_expr_type),
1659 NULL_RTX, VOIDmode, 0),
1661 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1662 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1667 /* If this expression is part of a ({...}) and is in memory, we may have
1668 to preserve temporaries. */
1669 preserve_temp_slots (last_expr_value);
1671 /* Free any temporaries used to evaluate this expression. Any temporary
1672 used as a result of this expression will already have been preserved
1679 /* Warn if EXP contains any computations whose results are not used.
1680 Return 1 if a warning is printed; 0 otherwise. */
1683 warn_if_unused_value (exp)
1686 if (TREE_USED (exp))
1689 switch (TREE_CODE (exp))
1691 case PREINCREMENT_EXPR:
1692 case POSTINCREMENT_EXPR:
1693 case PREDECREMENT_EXPR:
1694 case POSTDECREMENT_EXPR:
1699 case METHOD_CALL_EXPR:
1701 case WITH_CLEANUP_EXPR:
1703 /* We don't warn about COND_EXPR because it may be a useful
1704 construct if either arm contains a side effect. */
1709 /* For a binding, warn if no side effect within it. */
1710 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1712 case TRUTH_ORIF_EXPR:
1713 case TRUTH_ANDIF_EXPR:
1714 /* In && or ||, warn if 2nd operand has no side effect. */
1715 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1718 if (TREE_NO_UNUSED_WARNING (exp))
1720 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1722 /* Let people do `(foo (), 0)' without a warning. */
1723 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1725 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1729 case NON_LVALUE_EXPR:
1730 /* Don't warn about values cast to void. */
1731 if (TREE_TYPE (exp) == void_type_node)
1733 /* Don't warn about conversions not explicit in the user's program. */
1734 if (TREE_NO_UNUSED_WARNING (exp))
1736 /* Assignment to a cast usually results in a cast of a modify.
1737 Don't complain about that. There can be an arbitrary number of
1738 casts before the modify, so we must loop until we find the first
1739 non-cast expression and then test to see if that is a modify. */
1741 tree tem = TREE_OPERAND (exp, 0);
1743 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1744 tem = TREE_OPERAND (tem, 0);
1746 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR)
1749 /* ... fall through ... */
1752 /* Referencing a volatile value is a side effect, so don't warn. */
1753 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1754 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1755 && TREE_THIS_VOLATILE (exp))
1757 warning_with_file_and_line (emit_filename, emit_lineno,
1758 "value computed is not used");
1763 /* Clear out the memory of the last expression evaluated. */
1771 /* Begin a statement which will return a value.
1772 Return the RTL_EXPR for this statement expr.
1773 The caller must save that value and pass it to expand_end_stmt_expr. */
1776 expand_start_stmt_expr ()
1781 /* When generating bytecode just note down the stack depth */
1782 if (output_bytecode)
1783 return (build_int_2 (stack_depth, 0));
1785 /* Make the RTL_EXPR node temporary, not momentary,
1786 so that rtl_expr_chain doesn't become garbage. */
1787 momentary = suspend_momentary ();
1788 t = make_node (RTL_EXPR);
1789 resume_momentary (momentary);
1790 start_sequence_for_rtl_expr (t);
1792 expr_stmts_for_value++;
1796 /* Restore the previous state at the end of a statement that returns a value.
1797 Returns a tree node representing the statement's value and the
1798 insns to compute the value.
1800 The nodes of that expression have been freed by now, so we cannot use them.
1801 But we don't want to do that anyway; the expression has already been
1802 evaluated and now we just want to use the value. So generate a RTL_EXPR
1803 with the proper type and RTL value.
1805 If the last substatement was not an expression,
1806 return something with type `void'. */
1809 expand_end_stmt_expr (t)
1812 if (output_bytecode)
1818 /* At this point, all expressions have been evaluated in order.
1819 However, all expression values have been popped when evaluated,
1820 which means we have to recover the last expression value. This is
1821 the last value removed by means of a `drop' instruction. Instead
1822 of adding code to inhibit dropping the last expression value, it
1823 is here recovered by undoing the `drop'. Since `drop' is
1824 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1827 bc_adjust_stack (-1);
1829 if (!last_expr_type)
1830 last_expr_type = void_type_node;
1832 t = make_node (RTL_EXPR);
1833 TREE_TYPE (t) = last_expr_type;
1834 RTL_EXPR_RTL (t) = NULL;
1835 RTL_EXPR_SEQUENCE (t) = NULL;
1837 /* Don't consider deleting this expr or containing exprs at tree level. */
1838 TREE_THIS_VOLATILE (t) = 1;
1846 if (last_expr_type == 0)
1848 last_expr_type = void_type_node;
1849 last_expr_value = const0_rtx;
1851 else if (last_expr_value == 0)
1852 /* There are some cases where this can happen, such as when the
1853 statement is void type. */
1854 last_expr_value = const0_rtx;
1855 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1856 /* Remove any possible QUEUED. */
1857 last_expr_value = protect_from_queue (last_expr_value, 0);
1861 TREE_TYPE (t) = last_expr_type;
1862 RTL_EXPR_RTL (t) = last_expr_value;
1863 RTL_EXPR_SEQUENCE (t) = get_insns ();
1865 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1869 /* Don't consider deleting this expr or containing exprs at tree level. */
1870 TREE_SIDE_EFFECTS (t) = 1;
1871 /* Propagate volatility of the actual RTL expr. */
1872 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1875 expr_stmts_for_value--;
1880 /* Generate RTL for the start of an if-then. COND is the expression
1881 whose truth should be tested.
1883 If EXITFLAG is nonzero, this conditional is visible to
1884 `exit_something'. */
1887 expand_start_cond (cond, exitflag)
1891 struct nesting *thiscond = ALLOC_NESTING ();
1893 /* Make an entry on cond_stack for the cond we are entering. */
1895 thiscond->next = cond_stack;
1896 thiscond->all = nesting_stack;
1897 thiscond->depth = ++nesting_depth;
1898 thiscond->data.cond.next_label = gen_label_rtx ();
1899 /* Before we encounter an `else', we don't need a separate exit label
1900 unless there are supposed to be exit statements
1901 to exit this conditional. */
1902 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1903 thiscond->data.cond.endif_label = thiscond->exit_label;
1904 cond_stack = thiscond;
1905 nesting_stack = thiscond;
1907 if (output_bytecode)
1908 bc_expand_start_cond (cond, exitflag);
1910 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1913 /* Generate RTL between then-clause and the elseif-clause
1914 of an if-then-elseif-.... */
1917 expand_start_elseif (cond)
1920 if (cond_stack->data.cond.endif_label == 0)
1921 cond_stack->data.cond.endif_label = gen_label_rtx ();
1922 emit_jump (cond_stack->data.cond.endif_label);
1923 emit_label (cond_stack->data.cond.next_label);
1924 cond_stack->data.cond.next_label = gen_label_rtx ();
1925 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1928 /* Generate RTL between the then-clause and the else-clause
1929 of an if-then-else. */
1932 expand_start_else ()
1934 if (cond_stack->data.cond.endif_label == 0)
1935 cond_stack->data.cond.endif_label = gen_label_rtx ();
1937 if (output_bytecode)
1939 bc_expand_start_else ();
1943 emit_jump (cond_stack->data.cond.endif_label);
1944 emit_label (cond_stack->data.cond.next_label);
1945 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
1948 /* After calling expand_start_else, turn this "else" into an "else if"
1949 by providing another condition. */
1952 expand_elseif (cond)
1955 cond_stack->data.cond.next_label = gen_label_rtx ();
1956 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1959 /* Generate RTL for the end of an if-then.
1960 Pop the record for it off of cond_stack. */
1965 struct nesting *thiscond = cond_stack;
1967 if (output_bytecode)
1968 bc_expand_end_cond ();
1971 do_pending_stack_adjust ();
1972 if (thiscond->data.cond.next_label)
1973 emit_label (thiscond->data.cond.next_label);
1974 if (thiscond->data.cond.endif_label)
1975 emit_label (thiscond->data.cond.endif_label);
1978 POPSTACK (cond_stack);
1983 /* Generate code for the start of an if-then. COND is the expression
1984 whose truth is to be tested; if EXITFLAG is nonzero this conditional
1985 is to be visible to exit_something. It is assumed that the caller
1986 has pushed the previous context on the cond stack. */
1989 bc_expand_start_cond (cond, exitflag)
1993 struct nesting *thiscond = cond_stack;
1995 thiscond->data.case_stmt.nominal_type = cond;
1997 thiscond->exit_label = gen_label_rtx ();
1998 bc_expand_expr (cond);
1999 bc_emit_bytecode (xjumpifnot);
2000 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2002 #ifdef DEBUG_PRINT_CODE
2003 fputc ('\n', stderr);
2007 /* Generate the label for the end of an if with
2011 bc_expand_end_cond ()
2013 struct nesting *thiscond = cond_stack;
2015 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2018 /* Generate code for the start of the else- clause of
2022 bc_expand_start_else ()
2024 struct nesting *thiscond = cond_stack;
2026 thiscond->data.cond.endif_label = thiscond->exit_label;
2027 thiscond->exit_label = gen_label_rtx ();
2028 bc_emit_bytecode (jump);
2029 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2031 #ifdef DEBUG_PRINT_CODE
2032 fputc ('\n', stderr);
2035 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2038 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2039 loop should be exited by `exit_something'. This is a loop for which
2040 `expand_continue' will jump to the top of the loop.
2042 Make an entry on loop_stack to record the labels associated with
2046 expand_start_loop (exit_flag)
2049 register struct nesting *thisloop = ALLOC_NESTING ();
2051 /* Make an entry on loop_stack for the loop we are entering. */
2053 thisloop->next = loop_stack;
2054 thisloop->all = nesting_stack;
2055 thisloop->depth = ++nesting_depth;
2056 thisloop->data.loop.start_label = gen_label_rtx ();
2057 thisloop->data.loop.end_label = gen_label_rtx ();
2058 thisloop->data.loop.alt_end_label = 0;
2059 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2060 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2061 loop_stack = thisloop;
2062 nesting_stack = thisloop;
2064 if (output_bytecode)
2066 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2070 do_pending_stack_adjust ();
2072 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2073 emit_label (thisloop->data.loop.start_label);
2078 /* Like expand_start_loop but for a loop where the continuation point
2079 (for expand_continue_loop) will be specified explicitly. */
2082 expand_start_loop_continue_elsewhere (exit_flag)
2085 struct nesting *thisloop = expand_start_loop (exit_flag);
2086 loop_stack->data.loop.continue_label = gen_label_rtx ();
2090 /* Specify the continuation point for a loop started with
2091 expand_start_loop_continue_elsewhere.
2092 Use this at the point in the code to which a continue statement
2096 expand_loop_continue_here ()
2098 if (output_bytecode)
2100 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2103 do_pending_stack_adjust ();
2104 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2105 emit_label (loop_stack->data.loop.continue_label);
2111 bc_expand_end_loop ()
2113 struct nesting *thisloop = loop_stack;
2115 bc_emit_bytecode (jump);
2116 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2118 #ifdef DEBUG_PRINT_CODE
2119 fputc ('\n', stderr);
2122 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2123 POPSTACK (loop_stack);
2128 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2129 Pop the block off of loop_stack. */
2135 register rtx start_label;
2136 rtx last_test_insn = 0;
2139 if (output_bytecode)
2141 bc_expand_end_loop ();
2145 insn = get_last_insn ();
2146 start_label = loop_stack->data.loop.start_label;
2148 /* Mark the continue-point at the top of the loop if none elsewhere. */
2149 if (start_label == loop_stack->data.loop.continue_label)
2150 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2152 do_pending_stack_adjust ();
2154 /* If optimizing, perhaps reorder the loop. If the loop
2155 starts with a conditional exit, roll that to the end
2156 where it will optimize together with the jump back.
2158 We look for the last conditional branch to the exit that we encounter
2159 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2160 branch to the exit first, use it.
2162 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2163 because moving them is not valid. */
2167 ! (GET_CODE (insn) == JUMP_INSN
2168 && GET_CODE (PATTERN (insn)) == SET
2169 && SET_DEST (PATTERN (insn)) == pc_rtx
2170 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2172 /* Scan insns from the top of the loop looking for a qualified
2173 conditional exit. */
2174 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2175 insn = NEXT_INSN (insn))
2177 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2180 if (GET_CODE (insn) == NOTE
2181 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2182 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2185 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2188 if (last_test_insn && num_insns > 30)
2191 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2192 && SET_DEST (PATTERN (insn)) == pc_rtx
2193 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2194 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2195 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2196 == loop_stack->data.loop.end_label)
2197 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2198 == loop_stack->data.loop.alt_end_label)))
2199 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2200 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2201 == loop_stack->data.loop.end_label)
2202 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2203 == loop_stack->data.loop.alt_end_label)))))
2204 last_test_insn = insn;
2206 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2207 && GET_CODE (PATTERN (insn)) == SET
2208 && SET_DEST (PATTERN (insn)) == pc_rtx
2209 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2210 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2211 == loop_stack->data.loop.end_label)
2212 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2213 == loop_stack->data.loop.alt_end_label)))
2214 /* Include BARRIER. */
2215 last_test_insn = NEXT_INSN (insn);
2218 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2220 /* We found one. Move everything from there up
2221 to the end of the loop, and add a jump into the loop
2222 to jump to there. */
2223 register rtx newstart_label = gen_label_rtx ();
2224 register rtx start_move = start_label;
2226 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2227 then we want to move this note also. */
2228 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2229 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2230 == NOTE_INSN_LOOP_CONT))
2231 start_move = PREV_INSN (start_move);
2233 emit_label_after (newstart_label, PREV_INSN (start_move));
2234 reorder_insns (start_move, last_test_insn, get_last_insn ());
2235 emit_jump_insn_after (gen_jump (start_label),
2236 PREV_INSN (newstart_label));
2237 emit_barrier_after (PREV_INSN (newstart_label));
2238 start_label = newstart_label;
2242 emit_jump (start_label);
2243 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2244 emit_label (loop_stack->data.loop.end_label);
2246 POPSTACK (loop_stack);
2251 /* Generate a jump to the current loop's continue-point.
2252 This is usually the top of the loop, but may be specified
2253 explicitly elsewhere. If not currently inside a loop,
2254 return 0 and do nothing; caller will print an error message. */
2257 expand_continue_loop (whichloop)
2258 struct nesting *whichloop;
2262 whichloop = loop_stack;
2265 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2270 /* Generate a jump to exit the current loop. If not currently inside a loop,
2271 return 0 and do nothing; caller will print an error message. */
2274 expand_exit_loop (whichloop)
2275 struct nesting *whichloop;
2279 whichloop = loop_stack;
2282 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2286 /* Generate a conditional jump to exit the current loop if COND
2287 evaluates to zero. If not currently inside a loop,
2288 return 0 and do nothing; caller will print an error message. */
2291 expand_exit_loop_if_false (whichloop, cond)
2292 struct nesting *whichloop;
2297 whichloop = loop_stack;
2300 if (output_bytecode)
2302 bc_expand_expr (cond);
2303 bc_expand_goto_internal (xjumpifnot,
2304 BYTECODE_BC_LABEL (whichloop->exit_label),
2309 /* In order to handle fixups, we actually create a conditional jump
2310 around a unconditional branch to exit the loop. If fixups are
2311 necessary, they go before the unconditional branch. */
2313 rtx label = gen_label_rtx ();
2316 do_jump (cond, NULL_RTX, label);
2317 last_insn = get_last_insn ();
2318 if (GET_CODE (last_insn) == CODE_LABEL)
2319 whichloop->data.loop.alt_end_label = last_insn;
2320 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2328 /* Return non-zero if we should preserve sub-expressions as separate
2329 pseudos. We never do so if we aren't optimizing. We always do so
2330 if -fexpensive-optimizations.
2332 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2333 the loop may still be a small one. */
2336 preserve_subexpressions_p ()
2340 if (flag_expensive_optimizations)
2343 if (optimize == 0 || loop_stack == 0)
2346 insn = get_last_insn_anywhere ();
2349 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2350 < n_non_fixed_regs * 3));
2354 /* Generate a jump to exit the current loop, conditional, binding contour
2355 or case statement. Not all such constructs are visible to this function,
2356 only those started with EXIT_FLAG nonzero. Individual languages use
2357 the EXIT_FLAG parameter to control which kinds of constructs you can
2360 If not currently inside anything that can be exited,
2361 return 0 and do nothing; caller will print an error message. */
2364 expand_exit_something ()
2368 for (n = nesting_stack; n; n = n->all)
2369 if (n->exit_label != 0)
2371 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2378 /* Generate RTL to return from the current function, with no value.
2379 (That is, we do not do anything about returning any value.) */
2382 expand_null_return ()
2384 struct nesting *block = block_stack;
2387 if (output_bytecode)
2389 bc_emit_instruction (ret);
2393 /* Does any pending block have cleanups? */
2395 while (block && block->data.block.cleanups == 0)
2396 block = block->next;
2398 /* If yes, use a goto to return, since that runs cleanups. */
2400 expand_null_return_1 (last_insn, block != 0);
2403 /* Generate RTL to return from the current function, with value VAL. */
2406 expand_value_return (val)
2409 struct nesting *block = block_stack;
2410 rtx last_insn = get_last_insn ();
2411 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2413 /* Copy the value to the return location
2414 unless it's already there. */
2416 if (return_reg != val)
2418 #ifdef PROMOTE_FUNCTION_RETURN
2419 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2420 int unsignedp = TREE_UNSIGNED (type);
2421 enum machine_mode mode
2422 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2425 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2426 convert_move (return_reg, val, unsignedp);
2429 emit_move_insn (return_reg, val);
2431 if (GET_CODE (return_reg) == REG
2432 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2433 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2435 /* Does any pending block have cleanups? */
2437 while (block && block->data.block.cleanups == 0)
2438 block = block->next;
2440 /* If yes, use a goto to return, since that runs cleanups.
2441 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2443 expand_null_return_1 (last_insn, block != 0);
2446 /* Output a return with no value. If LAST_INSN is nonzero,
2447 pretend that the return takes place after LAST_INSN.
2448 If USE_GOTO is nonzero then don't use a return instruction;
2449 go to the return label instead. This causes any cleanups
2450 of pending blocks to be executed normally. */
2453 expand_null_return_1 (last_insn, use_goto)
2457 rtx end_label = cleanup_label ? cleanup_label : return_label;
2459 clear_pending_stack_adjust ();
2460 do_pending_stack_adjust ();
2463 /* PCC-struct return always uses an epilogue. */
2464 if (current_function_returns_pcc_struct || use_goto)
2467 end_label = return_label = gen_label_rtx ();
2468 expand_goto_internal (NULL_TREE, end_label, last_insn);
2472 /* Otherwise output a simple return-insn if one is available,
2473 unless it won't do the job. */
2475 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2477 emit_jump_insn (gen_return ());
2483 /* Otherwise jump to the epilogue. */
2484 expand_goto_internal (NULL_TREE, end_label, last_insn);
2487 /* Generate RTL to evaluate the expression RETVAL and return it
2488 from the current function. */
2491 expand_return (retval)
2494 /* If there are any cleanups to be performed, then they will
2495 be inserted following LAST_INSN. It is desirable
2496 that the last_insn, for such purposes, should be the
2497 last insn before computing the return value. Otherwise, cleanups
2498 which call functions can clobber the return value. */
2499 /* ??? rms: I think that is erroneous, because in C++ it would
2500 run destructors on variables that might be used in the subsequent
2501 computation of the return value. */
2503 register rtx val = 0;
2507 struct nesting *block;
2509 /* Bytecode returns are quite simple, just leave the result on the
2510 arithmetic stack. */
2511 if (output_bytecode)
2513 bc_expand_expr (retval);
2514 bc_emit_instruction (ret);
2518 /* If function wants no value, give it none. */
2519 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2521 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2523 expand_null_return ();
2527 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2528 /* This is not sufficient. We also need to watch for cleanups of the
2529 expression we are about to expand. Unfortunately, we cannot know
2530 if it has cleanups until we expand it, and we want to change how we
2531 expand it depending upon if we need cleanups. We can't win. */
2533 cleanups = any_pending_cleanups (1);
2538 if (TREE_CODE (retval) == RESULT_DECL)
2539 retval_rhs = retval;
2540 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2541 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2542 retval_rhs = TREE_OPERAND (retval, 1);
2543 else if (TREE_TYPE (retval) == void_type_node)
2544 /* Recognize tail-recursive call to void function. */
2545 retval_rhs = retval;
2547 retval_rhs = NULL_TREE;
2549 /* Only use `last_insn' if there are cleanups which must be run. */
2550 if (cleanups || cleanup_label != 0)
2551 last_insn = get_last_insn ();
2553 /* Distribute return down conditional expr if either of the sides
2554 may involve tail recursion (see test below). This enhances the number
2555 of tail recursions we see. Don't do this always since it can produce
2556 sub-optimal code in some cases and we distribute assignments into
2557 conditional expressions when it would help. */
2559 if (optimize && retval_rhs != 0
2560 && frame_offset == 0
2561 && TREE_CODE (retval_rhs) == COND_EXPR
2562 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2563 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2565 rtx label = gen_label_rtx ();
2568 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2569 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2570 DECL_RESULT (current_function_decl),
2571 TREE_OPERAND (retval_rhs, 1));
2572 TREE_SIDE_EFFECTS (expr) = 1;
2573 expand_return (expr);
2576 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2577 DECL_RESULT (current_function_decl),
2578 TREE_OPERAND (retval_rhs, 2));
2579 TREE_SIDE_EFFECTS (expr) = 1;
2580 expand_return (expr);
2584 /* For tail-recursive call to current function,
2585 just jump back to the beginning.
2586 It's unsafe if any auto variable in this function
2587 has its address taken; for simplicity,
2588 require stack frame to be empty. */
2589 if (optimize && retval_rhs != 0
2590 && frame_offset == 0
2591 && TREE_CODE (retval_rhs) == CALL_EXPR
2592 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2593 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2594 /* Finish checking validity, and if valid emit code
2595 to set the argument variables for the new call. */
2596 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2597 DECL_ARGUMENTS (current_function_decl)))
2599 if (tail_recursion_label == 0)
2601 tail_recursion_label = gen_label_rtx ();
2602 emit_label_after (tail_recursion_label,
2603 tail_recursion_reentry);
2606 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2611 /* This optimization is safe if there are local cleanups
2612 because expand_null_return takes care of them.
2613 ??? I think it should also be safe when there is a cleanup label,
2614 because expand_null_return takes care of them, too.
2615 Any reason why not? */
2616 if (HAVE_return && cleanup_label == 0
2617 && ! current_function_returns_pcc_struct
2618 && BRANCH_COST <= 1)
2620 /* If this is return x == y; then generate
2621 if (x == y) return 1; else return 0;
2622 if we can do it with explicit return insns and
2623 branches are cheap. */
2625 switch (TREE_CODE (retval_rhs))
2633 case TRUTH_ANDIF_EXPR:
2634 case TRUTH_ORIF_EXPR:
2635 case TRUTH_AND_EXPR:
2637 case TRUTH_NOT_EXPR:
2638 case TRUTH_XOR_EXPR:
2639 op0 = gen_label_rtx ();
2640 jumpifnot (retval_rhs, op0);
2641 expand_value_return (const1_rtx);
2643 expand_value_return (const0_rtx);
2647 #endif /* HAVE_return */
2649 /* If the result is an aggregate that is being returned in one (or more)
2650 registers, load the registers here. The compiler currently can't handle
2651 copying a BLKmode value into registers. We could put this code in a
2652 more general area (for use by everyone instead of just function
2653 call/return), but until this feature is generally usable it is kept here
2654 (and in expand_call). */
2657 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2658 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2661 int big_endian_correction = 0;
2662 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2663 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2664 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2665 rtx result_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2666 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2667 enum machine_mode tmpmode;
2669 /* Structures smaller than a word are aligned to the least significant
2670 byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we
2671 must skip the empty high order bytes when calculating the bit
2673 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
2674 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
2676 for (i = 0; i < n_regs; i++)
2678 rtx reg = gen_reg_rtx (word_mode);
2679 rtx word = operand_subword_force (result_val, i, BLKmode);
2680 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2683 result_pseudos[i] = reg;
2685 /* Clobber REG and move each partword into it. Ensure we don't
2686 go past the end of the structure. Note that the loop below
2687 works because we've already verified that padding and
2688 endianness are compatable. */
2689 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
2692 bitpos < BITS_PER_WORD && bytes > 0;
2693 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
2695 int xbitpos = bitpos + big_endian_correction;
2697 store_bit_field (reg, bitsize, xbitpos, word_mode,
2698 extract_bit_field (word, bitsize, bitpos, 1,
2699 NULL_RTX, word_mode,
2701 bitsize / BITS_PER_UNIT,
2703 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2707 /* Now that the value is in pseudos, copy it to the result reg(s). */
2710 for (i = 0; i < n_regs; i++)
2711 emit_move_insn (gen_rtx (REG, word_mode, REGNO (result_reg) + i),
2714 /* Find the smallest integer mode large enough to hold the
2715 entire structure and use that mode instead of BLKmode
2716 on the USE insn for the return register. */
2717 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2718 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2719 tmpmode != MAX_MACHINE_MODE;
2720 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2722 /* Have we found a large enough mode? */
2723 if (GET_MODE_SIZE (tmpmode) >= bytes)
2727 /* No suitable mode found. */
2728 if (tmpmode == MAX_MACHINE_MODE)
2731 PUT_MODE (result_reg, tmpmode);
2733 expand_value_return (result_reg);
2737 && TREE_TYPE (retval_rhs) != void_type_node
2738 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2740 /* Calculate the return value into a pseudo reg. */
2741 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2743 /* All temporaries have now been used. */
2745 /* Return the calculated value, doing cleanups first. */
2746 expand_value_return (val);
2750 /* No cleanups or no hard reg used;
2751 calculate value into hard return reg. */
2752 expand_expr (retval, const0_rtx, VOIDmode, 0);
2755 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2759 /* Return 1 if the end of the generated RTX is not a barrier.
2760 This means code already compiled can drop through. */
2763 drop_through_at_end_p ()
2765 rtx insn = get_last_insn ();
2766 while (insn && GET_CODE (insn) == NOTE)
2767 insn = PREV_INSN (insn);
2768 return insn && GET_CODE (insn) != BARRIER;
2771 /* Emit code to alter this function's formal parms for a tail-recursive call.
2772 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2773 FORMALS is the chain of decls of formals.
2774 Return 1 if this can be done;
2775 otherwise return 0 and do not emit any code. */
2778 tail_recursion_args (actuals, formals)
2779 tree actuals, formals;
2781 register tree a = actuals, f = formals;
2783 register rtx *argvec;
2785 /* Check that number and types of actuals are compatible
2786 with the formals. This is not always true in valid C code.
2787 Also check that no formal needs to be addressable
2788 and that all formals are scalars. */
2790 /* Also count the args. */
2792 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2794 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2796 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2799 if (a != 0 || f != 0)
2802 /* Compute all the actuals. */
2804 argvec = (rtx *) alloca (i * sizeof (rtx));
2806 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2807 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2809 /* Find which actual values refer to current values of previous formals.
2810 Copy each of them now, before any formal is changed. */
2812 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2816 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2817 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2818 { copy = 1; break; }
2820 argvec[i] = copy_to_reg (argvec[i]);
2823 /* Store the values of the actuals into the formals. */
2825 for (f = formals, a = actuals, i = 0; f;
2826 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2828 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2829 emit_move_insn (DECL_RTL (f), argvec[i]);
2831 convert_move (DECL_RTL (f), argvec[i],
2832 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2839 /* Generate the RTL code for entering a binding contour.
2840 The variables are declared one by one, by calls to `expand_decl'.
2842 EXIT_FLAG is nonzero if this construct should be visible to
2843 `exit_something'. */
2846 expand_start_bindings (exit_flag)
2849 struct nesting *thisblock = ALLOC_NESTING ();
2850 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2852 /* Make an entry on block_stack for the block we are entering. */
2854 thisblock->next = block_stack;
2855 thisblock->all = nesting_stack;
2856 thisblock->depth = ++nesting_depth;
2857 thisblock->data.block.stack_level = 0;
2858 thisblock->data.block.cleanups = 0;
2859 thisblock->data.block.function_call_count = 0;
2863 if (block_stack->data.block.cleanups == NULL_TREE
2864 && (block_stack->data.block.outer_cleanups == NULL_TREE
2865 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2866 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2868 thisblock->data.block.outer_cleanups
2869 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2870 block_stack->data.block.outer_cleanups);
2873 thisblock->data.block.outer_cleanups = 0;
2877 && !(block_stack->data.block.cleanups == NULL_TREE
2878 && block_stack->data.block.outer_cleanups == NULL_TREE))
2879 thisblock->data.block.outer_cleanups
2880 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2881 block_stack->data.block.outer_cleanups);
2883 thisblock->data.block.outer_cleanups = 0;
2885 thisblock->data.block.label_chain = 0;
2886 thisblock->data.block.innermost_stack_block = stack_block_stack;
2887 thisblock->data.block.first_insn = note;
2888 thisblock->data.block.block_start_count = ++block_start_count;
2889 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2890 block_stack = thisblock;
2891 nesting_stack = thisblock;
2893 if (!output_bytecode)
2895 /* Make a new level for allocating stack slots. */
2900 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2901 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2905 remember_end_note (block)
2906 register tree block;
2908 BLOCK_END_NOTE (block) = last_block_end_note;
2909 last_block_end_note = NULL_RTX;
2912 /* Generate RTL code to terminate a binding contour.
2913 VARS is the chain of VAR_DECL nodes
2914 for the variables bound in this contour.
2915 MARK_ENDS is nonzero if we should put a note at the beginning
2916 and end of this binding contour.
2918 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2919 (That is true automatically if the contour has a saved stack level.) */
2922 expand_end_bindings (vars, mark_ends, dont_jump_in)
2927 register struct nesting *thisblock = block_stack;
2930 if (output_bytecode)
2932 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
2937 for (decl = vars; decl; decl = TREE_CHAIN (decl))
2938 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
2939 && ! DECL_IN_SYSTEM_HEADER (decl))
2940 warning_with_decl (decl, "unused variable `%s'");
2942 if (thisblock->exit_label)
2944 do_pending_stack_adjust ();
2945 emit_label (thisblock->exit_label);
2948 /* If necessary, make a handler for nonlocal gotos taking
2949 place in the function calls in this block. */
2950 if (function_call_count != thisblock->data.block.function_call_count
2952 /* Make handler for outermost block
2953 if there were any nonlocal gotos to this function. */
2954 && (thisblock->next == 0 ? current_function_has_nonlocal_label
2955 /* Make handler for inner block if it has something
2956 special to do when you jump out of it. */
2957 : (thisblock->data.block.cleanups != 0
2958 || thisblock->data.block.stack_level != 0)))
2961 rtx afterward = gen_label_rtx ();
2962 rtx handler_label = gen_label_rtx ();
2963 rtx save_receiver = gen_reg_rtx (Pmode);
2966 /* Don't let jump_optimize delete the handler. */
2967 LABEL_PRESERVE_P (handler_label) = 1;
2969 /* Record the handler address in the stack slot for that purpose,
2970 during this block, saving and restoring the outer value. */
2971 if (thisblock->next != 0)
2973 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
2976 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
2977 insns = get_insns ();
2979 emit_insns_before (insns, thisblock->data.block.first_insn);
2983 emit_move_insn (nonlocal_goto_handler_slot,
2984 gen_rtx (LABEL_REF, Pmode, handler_label));
2985 insns = get_insns ();
2987 emit_insns_before (insns, thisblock->data.block.first_insn);
2989 /* Jump around the handler; it runs only when specially invoked. */
2990 emit_jump (afterward);
2991 emit_label (handler_label);
2993 #ifdef HAVE_nonlocal_goto
2994 if (! HAVE_nonlocal_goto)
2996 /* First adjust our frame pointer to its actual value. It was
2997 previously set to the start of the virtual area corresponding to
2998 the stacked variables when we branched here and now needs to be
2999 adjusted to the actual hardware fp value.
3001 Assignments are to virtual registers are converted by
3002 instantiate_virtual_regs into the corresponding assignment
3003 to the underlying register (fp in this case) that makes
3004 the original assignment true.
3005 So the following insn will actually be
3006 decrementing fp by STARTING_FRAME_OFFSET. */
3007 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3009 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3010 if (fixed_regs[ARG_POINTER_REGNUM])
3012 #ifdef ELIMINABLE_REGS
3013 /* If the argument pointer can be eliminated in favor of the
3014 frame pointer, we don't need to restore it. We assume here
3015 that if such an elimination is present, it can always be used.
3016 This is the case on all known machines; if we don't make this
3017 assumption, we do unnecessary saving on many machines. */
3018 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3021 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3022 if (elim_regs[i].from == ARG_POINTER_REGNUM
3023 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3026 if (i == sizeof elim_regs / sizeof elim_regs [0])
3029 /* Now restore our arg pointer from the address at which it
3030 was saved in our stack frame.
3031 If there hasn't be space allocated for it yet, make
3033 if (arg_pointer_save_area == 0)
3034 arg_pointer_save_area
3035 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3036 emit_move_insn (virtual_incoming_args_rtx,
3037 /* We need a pseudo here, or else
3038 instantiate_virtual_regs_1 complains. */
3039 copy_to_reg (arg_pointer_save_area));
3044 /* The handler expects the desired label address in the static chain
3045 register. It tests the address and does an appropriate jump
3046 to whatever label is desired. */
3047 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3048 /* Skip any labels we shouldn't be able to jump to from here. */
3049 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3051 rtx not_this = gen_label_rtx ();
3052 rtx this = gen_label_rtx ();
3053 do_jump_if_equal (static_chain_rtx,
3054 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3056 emit_jump (not_this);
3058 expand_goto (TREE_VALUE (link));
3059 emit_label (not_this);
3061 /* If label is not recognized, abort. */
3062 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3064 emit_label (afterward);
3067 /* Don't allow jumping into a block that has cleanups or a stack level. */
3069 || thisblock->data.block.stack_level != 0
3070 || thisblock->data.block.cleanups != 0)
3072 struct label_chain *chain;
3074 /* Any labels in this block are no longer valid to go to.
3075 Mark them to cause an error message. */
3076 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3078 DECL_TOO_LATE (chain->label) = 1;
3079 /* If any goto without a fixup came to this label,
3080 that must be an error, because gotos without fixups
3081 come from outside all saved stack-levels and all cleanups. */
3082 if (TREE_ADDRESSABLE (chain->label))
3083 error_with_decl (chain->label,
3084 "label `%s' used before containing binding contour");
3088 /* Restore stack level in effect before the block
3089 (only if variable-size objects allocated). */
3090 /* Perform any cleanups associated with the block. */
3092 if (thisblock->data.block.stack_level != 0
3093 || thisblock->data.block.cleanups != 0)
3095 /* Only clean up here if this point can actually be reached. */
3096 if (GET_CODE (get_last_insn ()) != BARRIER)
3098 /* Don't let cleanups affect ({...}) constructs. */
3099 int old_expr_stmts_for_value = expr_stmts_for_value;
3100 rtx old_last_expr_value = last_expr_value;
3101 tree old_last_expr_type = last_expr_type;
3102 expr_stmts_for_value = 0;
3104 /* Do the cleanups. */
3105 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0);
3106 do_pending_stack_adjust ();
3108 expr_stmts_for_value = old_expr_stmts_for_value;
3109 last_expr_value = old_last_expr_value;
3110 last_expr_type = old_last_expr_type;
3112 /* Restore the stack level. */
3114 if (thisblock->data.block.stack_level != 0)
3116 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3117 thisblock->data.block.stack_level, NULL_RTX);
3118 if (nonlocal_goto_handler_slot != 0)
3119 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3124 /* Any gotos out of this block must also do these things.
3125 Also report any gotos with fixups that came to labels in this
3127 fixup_gotos (thisblock,
3128 thisblock->data.block.stack_level,
3129 thisblock->data.block.cleanups,
3130 thisblock->data.block.first_insn,
3134 /* Mark the beginning and end of the scope if requested.
3135 We do this now, after running cleanups on the variables
3136 just going out of scope, so they are in scope for their cleanups. */
3139 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3141 /* Get rid of the beginning-mark if we don't make an end-mark. */
3142 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3144 /* If doing stupid register allocation, make sure lives of all
3145 register variables declared here extend thru end of scope. */
3148 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3150 rtx rtl = DECL_RTL (decl);
3151 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3155 /* Restore block_stack level for containing block. */
3157 stack_block_stack = thisblock->data.block.innermost_stack_block;
3158 POPSTACK (block_stack);
3160 /* Pop the stack slot nesting and free any slots at this level. */
3165 /* End a binding contour.
3166 VARS is the chain of VAR_DECL nodes for the variables bound
3167 in this contour. MARK_ENDS is nonzer if we should put a note
3168 at the beginning and end of this binding contour.
3169 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3173 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3178 struct nesting *thisbind = nesting_stack;
3182 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3183 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3184 warning_with_decl (decl, "unused variable `%s'");
3186 if (thisbind->exit_label)
3187 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3189 /* Pop block/bindings off stack */
3190 POPSTACK (block_stack);
3193 /* Generate RTL for the automatic variable declaration DECL.
3194 (Other kinds of declarations are simply ignored if seen here.)
3195 CLEANUP is an expression to be executed at exit from this binding contour;
3196 for example, in C++, it might call the destructor for this variable.
3198 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3199 either before or after calling `expand_decl' but before compiling
3200 any subsequent expressions. This is because CLEANUP may be expanded
3201 more than once, on different branches of execution.
3202 For the same reason, CLEANUP may not contain a CALL_EXPR
3203 except as its topmost node--else `preexpand_calls' would get confused.
3205 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3206 that is not associated with any particular variable.
3208 There is no special support here for C++ constructors.
3209 They should be handled by the proper code in DECL_INITIAL. */
3215 struct nesting *thisblock = block_stack;
3218 if (output_bytecode)
3220 bc_expand_decl (decl, 0);
3224 type = TREE_TYPE (decl);
3226 /* Only automatic variables need any expansion done.
3227 Static and external variables, and external functions,
3228 will be handled by `assemble_variable' (called from finish_decl).
3229 TYPE_DECL and CONST_DECL require nothing.
3230 PARM_DECLs are handled in `assign_parms'. */
3232 if (TREE_CODE (decl) != VAR_DECL)
3234 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3237 /* Create the RTL representation for the variable. */
3239 if (type == error_mark_node)
3240 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3241 else if (DECL_SIZE (decl) == 0)
3242 /* Variable with incomplete type. */
3244 if (DECL_INITIAL (decl) == 0)
3245 /* Error message was already done; now avoid a crash. */
3246 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3248 /* An initializer is going to decide the size of this array.
3249 Until we know the size, represent its address with a reg. */
3250 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3252 else if (DECL_MODE (decl) != BLKmode
3253 /* If -ffloat-store, don't put explicit float vars
3255 && !(flag_float_store
3256 && TREE_CODE (type) == REAL_TYPE)
3257 && ! TREE_THIS_VOLATILE (decl)
3258 && ! TREE_ADDRESSABLE (decl)
3259 && (DECL_REGISTER (decl) || ! obey_regdecls))
3261 /* Automatic variable that can go in a register. */
3262 int unsignedp = TREE_UNSIGNED (type);
3263 enum machine_mode reg_mode
3264 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3266 if (TREE_CODE (type) == COMPLEX_TYPE)
3268 rtx realpart, imagpart;
3269 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3271 /* For a complex type variable, make a CONCAT of two pseudos
3272 so that the real and imaginary parts
3273 can be allocated separately. */
3274 realpart = gen_reg_rtx (partmode);
3275 REG_USERVAR_P (realpart) = 1;
3276 imagpart = gen_reg_rtx (partmode);
3277 REG_USERVAR_P (imagpart) = 1;
3278 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3282 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3283 if (TREE_CODE (type) == POINTER_TYPE)
3284 mark_reg_pointer (DECL_RTL (decl));
3285 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3288 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3290 /* Variable of fixed size that goes on the stack. */
3294 /* If we previously made RTL for this decl, it must be an array
3295 whose size was determined by the initializer.
3296 The old address was a register; set that register now
3297 to the proper address. */
3298 if (DECL_RTL (decl) != 0)
3300 if (GET_CODE (DECL_RTL (decl)) != MEM
3301 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3303 oldaddr = XEXP (DECL_RTL (decl), 0);
3307 = assign_stack_temp (DECL_MODE (decl),
3308 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3309 + BITS_PER_UNIT - 1)
3313 /* Set alignment we actually gave this decl. */
3314 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3315 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3319 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3320 if (addr != oldaddr)
3321 emit_move_insn (oldaddr, addr);
3324 /* If this is a memory ref that contains aggregate components,
3325 mark it as such for cse and loop optimize. */
3326 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3328 /* If this is in memory because of -ffloat-store,
3329 set the volatile bit, to prevent optimizations from
3330 undoing the effects. */
3331 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3332 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3336 /* Dynamic-size object: must push space on the stack. */
3340 /* Record the stack pointer on entry to block, if have
3341 not already done so. */
3342 if (thisblock->data.block.stack_level == 0)
3344 do_pending_stack_adjust ();
3345 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3346 &thisblock->data.block.stack_level,
3347 thisblock->data.block.first_insn);
3348 stack_block_stack = thisblock;
3351 /* Compute the variable's size, in bytes. */
3352 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3354 size_int (BITS_PER_UNIT)),
3355 NULL_RTX, VOIDmode, 0);
3358 /* Allocate space on the stack for the variable. */
3359 address = allocate_dynamic_stack_space (size, NULL_RTX,
3362 /* Reference the variable indirect through that rtx. */
3363 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3365 /* If this is a memory ref that contains aggregate components,
3366 mark it as such for cse and loop optimize. */
3367 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3369 /* Indicate the alignment we actually gave this variable. */
3370 #ifdef STACK_BOUNDARY
3371 DECL_ALIGN (decl) = STACK_BOUNDARY;
3373 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3377 if (TREE_THIS_VOLATILE (decl))
3378 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3379 #if 0 /* A variable is not necessarily unchanging
3380 just because it is const. RTX_UNCHANGING_P
3381 means no change in the function,
3382 not merely no change in the variable's scope.
3383 It is correct to set RTX_UNCHANGING_P if the variable's scope
3384 is the whole function. There's no convenient way to test that. */
3385 if (TREE_READONLY (decl))
3386 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3389 /* If doing stupid register allocation, make sure life of any
3390 register variable starts here, at the start of its scope. */
3393 use_variable (DECL_RTL (decl));
3397 /* Generate code for the automatic variable declaration DECL. For
3398 most variables this just means we give it a stack offset. The
3399 compiler sometimes emits cleanups without variables and we will
3400 have to deal with those too. */
3403 bc_expand_decl (decl, cleanup)
3411 /* A cleanup with no variable. */
3418 /* Only auto variables need any work. */
3419 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3422 type = TREE_TYPE (decl);
3424 if (type == error_mark_node)
3425 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3427 else if (DECL_SIZE (decl) == 0)
3429 /* Variable with incomplete type. The stack offset herein will be
3430 fixed later in expand_decl_init (). */
3431 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3433 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3435 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3439 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3442 /* Emit code to perform the initialization of a declaration DECL. */
3445 expand_decl_init (decl)
3448 int was_used = TREE_USED (decl);
3450 if (output_bytecode)
3452 bc_expand_decl_init (decl);
3456 /* If this is a CONST_DECL, we don't have to generate any code, but
3457 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3458 to be set while in the obstack containing the constant. If we don't
3459 do this, we can lose if we have functions nested three deep and the middle
3460 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3461 the innermost function is the first to expand that STRING_CST. */
3462 if (TREE_CODE (decl) == CONST_DECL)
3464 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3465 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3466 EXPAND_INITIALIZER);
3470 if (TREE_STATIC (decl))
3473 /* Compute and store the initial value now. */
3475 if (DECL_INITIAL (decl) == error_mark_node)
3477 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3478 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3479 || code == POINTER_TYPE)
3480 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3484 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3486 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3487 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3491 /* Don't let the initialization count as "using" the variable. */
3492 TREE_USED (decl) = was_used;
3494 /* Free any temporaries we made while initializing the decl. */
3498 /* Expand initialization for variable-sized types. Allocate array
3499 using newlocalSI and set local variable, which is a pointer to the
3503 bc_expand_variable_local_init (decl)
3506 /* Evaluate size expression and coerce to SI */
3507 bc_expand_expr (DECL_SIZE (decl));
3509 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3510 no coercion is necessary (?) */
3512 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3513 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3515 /* Emit code to allocate array */
3516 bc_emit_instruction (newlocalSI);
3518 /* Store array pointer in local variable. This is the only instance
3519 where we actually want the address of the pointer to the
3520 variable-size block, rather than the pointer itself. We avoid
3521 using expand_address() since that would cause the pointer to be
3522 pushed rather than its address. Hence the hard-coded reference;
3523 notice also that the variable is always local (no global
3524 variable-size type variables). */
3526 bc_load_localaddr (DECL_RTL (decl));
3527 bc_emit_instruction (storeP);
3531 /* Emit code to initialize a declaration. */
3534 bc_expand_decl_init (decl)
3537 int org_stack_depth;
3539 /* Statical initializers are handled elsewhere */
3541 if (TREE_STATIC (decl))
3544 /* Memory original stack depth */
3545 org_stack_depth = stack_depth;
3547 /* If the type is variable-size, we first create its space (we ASSUME
3548 it CAN'T be static). We do this regardless of whether there's an
3549 initializer assignment or not. */
3551 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3552 bc_expand_variable_local_init (decl);
3554 /* Expand initializer assignment */
3555 if (DECL_INITIAL (decl) == error_mark_node)
3557 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3559 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3560 || code == POINTER_TYPE)
3562 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3564 else if (DECL_INITIAL (decl))
3565 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3567 /* Restore stack depth */
3568 if (org_stack_depth > stack_depth)
3571 bc_adjust_stack (stack_depth - org_stack_depth);
3575 /* CLEANUP is an expression to be executed at exit from this binding contour;
3576 for example, in C++, it might call the destructor for this variable.
3578 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3579 either before or after calling `expand_decl' but before compiling
3580 any subsequent expressions. This is because CLEANUP may be expanded
3581 more than once, on different branches of execution.
3582 For the same reason, CLEANUP may not contain a CALL_EXPR
3583 except as its topmost node--else `preexpand_calls' would get confused.
3585 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3586 that is not associated with any particular variable. */
3589 expand_decl_cleanup (decl, cleanup)
3592 struct nesting *thisblock = block_stack;
3594 /* Error if we are not in any block. */
3598 /* Record the cleanup if there is one. */
3602 thisblock->data.block.cleanups
3603 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3604 /* If this block has a cleanup, it belongs in stack_block_stack. */
3605 stack_block_stack = thisblock;
3606 (*interim_eh_hook) (NULL_TREE);
3611 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3612 DECL_ELTS is the list of elements that belong to DECL's type.
3613 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3616 expand_anon_union_decl (decl, cleanup, decl_elts)
3617 tree decl, cleanup, decl_elts;
3619 struct nesting *thisblock = block_stack;
3622 expand_decl (decl, cleanup);
3623 x = DECL_RTL (decl);
3627 tree decl_elt = TREE_VALUE (decl_elts);
3628 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3629 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3631 /* Propagate the union's alignment to the elements. */
3632 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3634 /* If the element has BLKmode and the union doesn't, the union is
3635 aligned such that the element doesn't need to have BLKmode, so
3636 change the element's mode to the appropriate one for its size. */
3637 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3638 DECL_MODE (decl_elt) = mode
3639 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3642 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3643 instead create a new MEM rtx with the proper mode. */
3644 if (GET_CODE (x) == MEM)
3646 if (mode == GET_MODE (x))
3647 DECL_RTL (decl_elt) = x;
3650 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3651 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3652 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3655 else if (GET_CODE (x) == REG)
3657 if (mode == GET_MODE (x))
3658 DECL_RTL (decl_elt) = x;
3660 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3665 /* Record the cleanup if there is one. */
3668 thisblock->data.block.cleanups
3669 = temp_tree_cons (decl_elt, cleanup_elt,
3670 thisblock->data.block.cleanups);
3672 decl_elts = TREE_CHAIN (decl_elts);
3676 /* Expand a list of cleanups LIST.
3677 Elements may be expressions or may be nested lists.
3679 If DONT_DO is nonnull, then any list-element
3680 whose TREE_PURPOSE matches DONT_DO is omitted.
3681 This is sometimes used to avoid a cleanup associated with
3682 a value that is being returned out of the scope.
3684 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3685 goto and handle protection regions specially in that case. */
3688 expand_cleanups (list, dont_do, in_fixup)
3694 for (tail = list; tail; tail = TREE_CHAIN (tail))
3695 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3697 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3698 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup);
3702 (*interim_eh_hook) (TREE_VALUE (tail));
3704 /* Cleanups may be run multiple times. For example,
3705 when exiting a binding contour, we expand the
3706 cleanups associated with that contour. When a goto
3707 within that binding contour has a target outside that
3708 contour, it will expand all cleanups from its scope to
3709 the target. Though the cleanups are expanded multiple
3710 times, the control paths are non-overlapping so the
3711 cleanups will not be executed twice. */
3712 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3718 /* Move all cleanups from the current block_stack
3719 to the containing block_stack, where they are assumed to
3720 have been created. If anything can cause a temporary to
3721 be created, but not expanded for more than one level of
3722 block_stacks, then this code will have to change. */
3727 struct nesting *block = block_stack;
3728 struct nesting *outer = block->next;
3730 outer->data.block.cleanups
3731 = chainon (block->data.block.cleanups,
3732 outer->data.block.cleanups);
3733 block->data.block.cleanups = 0;
3737 last_cleanup_this_contour ()
3739 if (block_stack == 0)
3742 return block_stack->data.block.cleanups;
3745 /* Return 1 if there are any pending cleanups at this point.
3746 If THIS_CONTOUR is nonzero, check the current contour as well.
3747 Otherwise, look only at the contours that enclose this one. */
3750 any_pending_cleanups (this_contour)
3753 struct nesting *block;
3755 if (block_stack == 0)
3758 if (this_contour && block_stack->data.block.cleanups != NULL)
3760 if (block_stack->data.block.cleanups == 0
3761 && (block_stack->data.block.outer_cleanups == 0
3763 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3768 for (block = block_stack->next; block; block = block->next)
3769 if (block->data.block.cleanups != 0)
3775 /* Enter a case (Pascal) or switch (C) statement.
3776 Push a block onto case_stack and nesting_stack
3777 to accumulate the case-labels that are seen
3778 and to record the labels generated for the statement.
3780 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3781 Otherwise, this construct is transparent for `exit_something'.
3783 EXPR is the index-expression to be dispatched on.
3784 TYPE is its nominal type. We could simply convert EXPR to this type,
3785 but instead we take short cuts. */
3788 expand_start_case (exit_flag, expr, type, printname)
3794 register struct nesting *thiscase = ALLOC_NESTING ();
3796 /* Make an entry on case_stack for the case we are entering. */
3798 thiscase->next = case_stack;
3799 thiscase->all = nesting_stack;
3800 thiscase->depth = ++nesting_depth;
3801 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3802 thiscase->data.case_stmt.case_list = 0;
3803 thiscase->data.case_stmt.index_expr = expr;
3804 thiscase->data.case_stmt.nominal_type = type;
3805 thiscase->data.case_stmt.default_label = 0;
3806 thiscase->data.case_stmt.num_ranges = 0;
3807 thiscase->data.case_stmt.printname = printname;
3808 thiscase->data.case_stmt.seenlabel = 0;
3809 case_stack = thiscase;
3810 nesting_stack = thiscase;
3812 if (output_bytecode)
3814 bc_expand_start_case (thiscase, expr, type, printname);
3818 do_pending_stack_adjust ();
3820 /* Make sure case_stmt.start points to something that won't
3821 need any transformation before expand_end_case. */
3822 if (GET_CODE (get_last_insn ()) != NOTE)
3823 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3825 thiscase->data.case_stmt.start = get_last_insn ();
3829 /* Enter a case statement. It is assumed that the caller has pushed
3830 the current context onto the case stack. */
3833 bc_expand_start_case (thiscase, expr, type, printname)
3834 struct nesting *thiscase;
3839 bc_expand_expr (expr);
3840 bc_expand_conversion (TREE_TYPE (expr), type);
3842 /* For cases, the skip is a place we jump to that's emitted after
3843 the size of the jump table is known. */
3845 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3846 bc_emit_bytecode (jump);
3847 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3849 #ifdef DEBUG_PRINT_CODE
3850 fputc ('\n', stderr);
3855 /* Start a "dummy case statement" within which case labels are invalid
3856 and are not connected to any larger real case statement.
3857 This can be used if you don't want to let a case statement jump
3858 into the middle of certain kinds of constructs. */
3861 expand_start_case_dummy ()
3863 register struct nesting *thiscase = ALLOC_NESTING ();
3865 /* Make an entry on case_stack for the dummy. */
3867 thiscase->next = case_stack;
3868 thiscase->all = nesting_stack;
3869 thiscase->depth = ++nesting_depth;
3870 thiscase->exit_label = 0;
3871 thiscase->data.case_stmt.case_list = 0;
3872 thiscase->data.case_stmt.start = 0;
3873 thiscase->data.case_stmt.nominal_type = 0;
3874 thiscase->data.case_stmt.default_label = 0;
3875 thiscase->data.case_stmt.num_ranges = 0;
3876 case_stack = thiscase;
3877 nesting_stack = thiscase;
3880 /* End a dummy case statement. */
3883 expand_end_case_dummy ()
3885 POPSTACK (case_stack);
3888 /* Return the data type of the index-expression
3889 of the innermost case statement, or null if none. */
3892 case_index_expr_type ()
3895 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3899 /* Accumulate one case or default label inside a case or switch statement.
3900 VALUE is the value of the case (a null pointer, for a default label).
3901 The function CONVERTER, when applied to arguments T and V,
3902 converts the value V to the type T.
3904 If not currently inside a case or switch statement, return 1 and do
3905 nothing. The caller will print a language-specific error message.
3906 If VALUE is a duplicate or overlaps, return 2 and do nothing
3907 except store the (first) duplicate node in *DUPLICATE.
3908 If VALUE is out of range, return 3 and do nothing.
3909 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3910 Return 0 on success.
3912 Extended to handle range statements. */
3915 pushcase (value, converter, label, duplicate)
3916 register tree value;
3917 tree (*converter) PROTO((tree, tree));
3918 register tree label;
3921 register struct case_node **l;
3922 register struct case_node *n;
3926 if (output_bytecode)
3927 return bc_pushcase (value, label);
3929 /* Fail if not inside a real case statement. */
3930 if (! (case_stack && case_stack->data.case_stmt.start))
3933 if (stack_block_stack
3934 && stack_block_stack->depth > case_stack->depth)
3937 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
3938 nominal_type = case_stack->data.case_stmt.nominal_type;
3940 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3941 if (index_type == error_mark_node)
3944 /* Convert VALUE to the type in which the comparisons are nominally done. */
3946 value = (*converter) (nominal_type, value);
3948 /* If this is the first label, warn if any insns have been emitted. */
3949 if (case_stack->data.case_stmt.seenlabel == 0)
3952 for (insn = case_stack->data.case_stmt.start;
3954 insn = NEXT_INSN (insn))
3956 if (GET_CODE (insn) == CODE_LABEL)
3958 if (GET_CODE (insn) != NOTE
3959 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
3961 warning ("unreachable code at beginning of %s",
3962 case_stack->data.case_stmt.printname);
3967 case_stack->data.case_stmt.seenlabel = 1;
3969 /* Fail if this value is out of range for the actual type of the index
3970 (which may be narrower than NOMINAL_TYPE). */
3971 if (value != 0 && ! int_fits_type_p (value, index_type))
3974 /* Fail if this is a duplicate or overlaps another entry. */
3977 if (case_stack->data.case_stmt.default_label != 0)
3979 *duplicate = case_stack->data.case_stmt.default_label;
3982 case_stack->data.case_stmt.default_label = label;
3986 /* Find the elt in the chain before which to insert the new value,
3987 to keep the chain sorted in increasing order.
3988 But report an error if this element is a duplicate. */
3989 for (l = &case_stack->data.case_stmt.case_list;
3990 /* Keep going past elements distinctly less than VALUE. */
3991 *l != 0 && tree_int_cst_lt ((*l)->high, value);
3996 /* Element we will insert before must be distinctly greater;
3997 overlap means error. */
3998 if (! tree_int_cst_lt (value, (*l)->low))
4000 *duplicate = (*l)->code_label;
4005 /* Add this label to the chain, and succeed.
4006 Copy VALUE so it is on temporary rather than momentary
4007 obstack and will thus survive till the end of the case statement. */
4008 n = (struct case_node *) oballoc (sizeof (struct case_node));
4011 n->high = n->low = copy_node (value);
4012 n->code_label = label;
4016 expand_label (label);
4020 /* Like pushcase but this case applies to all values
4021 between VALUE1 and VALUE2 (inclusive).
4022 The return value is the same as that of pushcase
4023 but there is one additional error code:
4024 4 means the specified range was empty. */
4027 pushcase_range (value1, value2, converter, label, duplicate)
4028 register tree value1, value2;
4029 tree (*converter) PROTO((tree, tree));
4030 register tree label;
4033 register struct case_node **l;
4034 register struct case_node *n;
4038 /* Fail if not inside a real case statement. */
4039 if (! (case_stack && case_stack->data.case_stmt.start))
4042 if (stack_block_stack
4043 && stack_block_stack->depth > case_stack->depth)
4046 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4047 nominal_type = case_stack->data.case_stmt.nominal_type;
4049 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4050 if (index_type == error_mark_node)
4053 /* If this is the first label, warn if any insns have been emitted. */
4054 if (case_stack->data.case_stmt.seenlabel == 0)
4057 for (insn = case_stack->data.case_stmt.start;
4059 insn = NEXT_INSN (insn))
4061 if (GET_CODE (insn) == CODE_LABEL)
4063 if (GET_CODE (insn) != NOTE
4064 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4066 warning ("unreachable code at beginning of %s",
4067 case_stack->data.case_stmt.printname);
4072 case_stack->data.case_stmt.seenlabel = 1;
4074 /* Convert VALUEs to type in which the comparisons are nominally done. */
4075 if (value1 == 0) /* Negative infinity. */
4076 value1 = TYPE_MIN_VALUE(index_type);
4077 value1 = (*converter) (nominal_type, value1);
4079 if (value2 == 0) /* Positive infinity. */
4080 value2 = TYPE_MAX_VALUE(index_type);
4081 value2 = (*converter) (nominal_type, value2);
4083 /* Fail if these values are out of range. */
4084 if (! int_fits_type_p (value1, index_type))
4087 if (! int_fits_type_p (value2, index_type))
4090 /* Fail if the range is empty. */
4091 if (tree_int_cst_lt (value2, value1))
4094 /* If the bounds are equal, turn this into the one-value case. */
4095 if (tree_int_cst_equal (value1, value2))
4096 return pushcase (value1, converter, label, duplicate);
4098 /* Find the elt in the chain before which to insert the new value,
4099 to keep the chain sorted in increasing order.
4100 But report an error if this element is a duplicate. */
4101 for (l = &case_stack->data.case_stmt.case_list;
4102 /* Keep going past elements distinctly less than this range. */
4103 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4108 /* Element we will insert before must be distinctly greater;
4109 overlap means error. */
4110 if (! tree_int_cst_lt (value2, (*l)->low))
4112 *duplicate = (*l)->code_label;
4117 /* Add this label to the chain, and succeed.
4118 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4119 obstack and will thus survive till the end of the case statement. */
4121 n = (struct case_node *) oballoc (sizeof (struct case_node));
4124 n->low = copy_node (value1);
4125 n->high = copy_node (value2);
4126 n->code_label = label;
4129 expand_label (label);
4131 case_stack->data.case_stmt.num_ranges++;
4137 /* Accumulate one case or default label; VALUE is the value of the
4138 case, or nil for a default label. If not currently inside a case,
4139 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4140 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4141 Return 0 on success. This function is a leftover from the earlier
4142 bytecode compiler, which was based on gcc 1.37. It should be
4143 merged into pushcase. */
4146 bc_pushcase (value, label)
4150 struct nesting *thiscase = case_stack;
4151 struct case_node *case_label, *new_label;
4156 /* Fail if duplicate, overlap, or out of type range. */
4159 value = convert (thiscase->data.case_stmt.nominal_type, value);
4160 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4163 for (case_label = thiscase->data.case_stmt.case_list;
4164 case_label->left; case_label = case_label->left)
4165 if (! tree_int_cst_lt (case_label->left->high, value))
4168 if (case_label != thiscase->data.case_stmt.case_list
4169 && ! tree_int_cst_lt (case_label->high, value)
4170 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4173 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4174 new_label->low = new_label->high = copy_node (value);
4175 new_label->code_label = label;
4176 new_label->left = case_label->left;
4178 case_label->left = new_label;
4179 thiscase->data.case_stmt.num_ranges++;
4183 if (thiscase->data.case_stmt.default_label)
4185 thiscase->data.case_stmt.default_label = label;
4188 expand_label (label);
4192 /* Returns the number of possible values of TYPE.
4193 Returns -1 if the number is unknown or variable.
4194 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4195 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4196 do not increase monotonically (there may be duplicates);
4197 to 1 if the values increase monotonically, but not always by 1;
4198 otherwise sets it to 0. */
4201 all_cases_count (type, spareness)
4205 HOST_WIDE_INT count, count_high = 0;
4208 switch (TREE_CODE (type))
4215 count = 1 << BITS_PER_UNIT;
4219 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4220 || TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST)
4225 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4226 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4227 but with overflow checking. */
4228 tree mint = TYPE_MIN_VALUE (type);
4229 tree maxt = TYPE_MAX_VALUE (type);
4230 HOST_WIDE_INT lo, hi;
4231 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4233 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4235 add_double (lo, hi, 1, 0, &lo, &hi);
4236 if (hi != 0 || lo < 0)
4243 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4245 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4246 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4247 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4248 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4252 if (*spareness == 1)
4254 tree prev = TREE_VALUE (TYPE_VALUES (type));
4255 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4257 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4262 prev = TREE_VALUE (t);
4271 #define BITARRAY_TEST(ARRAY, INDEX) \
4272 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4273 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4274 #define BITARRAY_SET(ARRAY, INDEX) \
4275 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4276 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4278 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4279 with the case values we have seen, assuming the case expression
4281 SPARSENESS is as determined by all_cases_count.
4283 The time needed is propotional to COUNT, unless
4284 SPARSENESS is 2, in which case quadratic time is needed. */
4287 mark_seen_cases (type, cases_seen, count, sparseness)
4289 unsigned char *cases_seen;
4295 tree next_node_to_try = NULL_TREE;
4296 long next_node_offset = 0;
4298 register struct case_node *n;
4299 tree val = make_node (INTEGER_CST);
4300 TREE_TYPE (val) = type;
4301 for (n = case_stack->data.case_stmt.case_list; n;
4304 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4305 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4306 while ( ! tree_int_cst_lt (n->high, val))
4308 /* Calculate (into xlo) the "offset" of the integer (val).
4309 The element with lowest value has offset 0, the next smallest
4310 element has offset 1, etc. */
4312 HOST_WIDE_INT xlo, xhi;
4314 if (sparseness == 2)
4316 /* This less efficient loop is only needed to handle
4317 duplicate case values (multiple enum constants
4318 with the same value). */
4319 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4320 t = TREE_CHAIN (t), xlo++)
4322 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4323 BITARRAY_SET (cases_seen, xlo);
4328 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4330 /* The TYPE_VALUES will be in increasing order, so
4331 starting searching where we last ended. */
4332 t = next_node_to_try;
4333 xlo = next_node_offset;
4339 t = TYPE_VALUES (type);
4342 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4344 next_node_to_try = TREE_CHAIN (t);
4345 next_node_offset = xlo + 1;
4350 if (t == next_node_to_try)
4356 t = TYPE_MIN_VALUE (type);
4358 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4362 add_double (xlo, xhi,
4363 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4367 if (xhi == 0 && xlo >= 0 && xlo < count)
4368 BITARRAY_SET (cases_seen, xlo);
4370 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4372 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4377 /* Called when the index of a switch statement is an enumerated type
4378 and there is no default label.
4380 Checks that all enumeration literals are covered by the case
4381 expressions of a switch. Also, warn if there are any extra
4382 switch cases that are *not* elements of the enumerated type.
4384 If all enumeration literals were covered by the case expressions,
4385 turn one of the expressions into the default expression since it should
4386 not be possible to fall through such a switch. */
4389 check_for_full_enumeration_handling (type)
4392 register struct case_node *n;
4393 register struct case_node **l;
4394 register tree chain;
4397 /* True iff the selector type is a numbered set mode. */
4400 /* The number of possible selector values. */
4403 /* For each possible selector value. a one iff it has been matched
4404 by a case value alternative. */
4405 unsigned char *cases_seen;
4407 /* The allocated size of cases_seen, in chars. */
4411 if (output_bytecode)
4413 bc_check_for_full_enumeration_handling (type);
4420 size = all_cases_count (type, &sparseness);
4421 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4423 if (size > 0 && size < 600000
4424 /* We deliberately use malloc here - not xmalloc. */
4425 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4428 tree v = TYPE_VALUES (type);
4429 bzero (cases_seen, bytes_needed);
4431 /* The time complexity of this code is normally O(N), where
4432 N being the number of members in the enumerated type.
4433 However, if type is a ENUMERAL_TYPE whose values do not
4434 increase monotonically, quadratic time may be needed. */
4436 mark_seen_cases (type, cases_seen, size, sparseness);
4438 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4440 if (BITARRAY_TEST(cases_seen, i) == 0)
4441 warning ("enumeration value `%s' not handled in switch",
4442 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4448 /* Now we go the other way around; we warn if there are case
4449 expressions that don't correspond to enumerators. This can
4450 occur since C and C++ don't enforce type-checking of
4451 assignments to enumeration variables. */
4454 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4456 for (chain = TYPE_VALUES (type);
4457 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4458 chain = TREE_CHAIN (chain))
4463 if (TYPE_NAME (type) == 0)
4464 warning ("case value `%d' not in enumerated type",
4465 TREE_INT_CST_LOW (n->low));
4467 warning ("case value `%d' not in enumerated type `%s'",
4468 TREE_INT_CST_LOW (n->low),
4469 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4472 : DECL_NAME (TYPE_NAME (type))));
4474 if (!tree_int_cst_equal (n->low, n->high))
4476 for (chain = TYPE_VALUES (type);
4477 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4478 chain = TREE_CHAIN (chain))
4483 if (TYPE_NAME (type) == 0)
4484 warning ("case value `%d' not in enumerated type",
4485 TREE_INT_CST_LOW (n->high));
4487 warning ("case value `%d' not in enumerated type `%s'",
4488 TREE_INT_CST_LOW (n->high),
4489 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4492 : DECL_NAME (TYPE_NAME (type))));
4498 /* ??? This optimization is disabled because it causes valid programs to
4499 fail. ANSI C does not guarantee that an expression with enum type
4500 will have a value that is the same as one of the enumation literals. */
4502 /* If all values were found as case labels, make one of them the default
4503 label. Thus, this switch will never fall through. We arbitrarily pick
4504 the last one to make the default since this is likely the most
4505 efficient choice. */
4509 for (l = &case_stack->data.case_stmt.case_list;
4514 case_stack->data.case_stmt.default_label = (*l)->code_label;
4521 /* Check that all enumeration literals are covered by the case
4522 expressions of a switch. Also warn if there are any cases
4523 that are not elements of the enumerated type. */
4526 bc_check_for_full_enumeration_handling (type)
4529 struct nesting *thiscase = case_stack;
4530 struct case_node *c;
4533 /* Check for enums not handled. */
4534 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4536 for (c = thiscase->data.case_stmt.case_list->left;
4537 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4540 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4541 warning ("enumerated value `%s' not handled in switch",
4542 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4545 /* Check for cases not in the enumeration. */
4546 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4548 for (e = TYPE_VALUES (type);
4549 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4553 warning ("case value `%d' not in enumerated type `%s'",
4554 TREE_INT_CST_LOW (c->low),
4555 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4557 : DECL_NAME (TYPE_NAME (type))));
4561 /* Terminate a case (Pascal) or switch (C) statement
4562 in which ORIG_INDEX is the expression to be tested.
4563 Generate the code to test it and jump to the right place. */
4566 expand_end_case (orig_index)
4569 tree minval, maxval, range, orig_minval;
4570 rtx default_label = 0;
4571 register struct case_node *n;
4579 register struct nesting *thiscase = case_stack;
4580 tree index_expr, index_type;
4583 if (output_bytecode)
4585 bc_expand_end_case (orig_index);
4589 table_label = gen_label_rtx ();
4590 index_expr = thiscase->data.case_stmt.index_expr;
4591 index_type = TREE_TYPE (index_expr);
4592 unsignedp = TREE_UNSIGNED (index_type);
4594 do_pending_stack_adjust ();
4596 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4597 if (index_type != error_mark_node)
4599 /* If switch expression was an enumerated type, check that all
4600 enumeration literals are covered by the cases.
4601 No sense trying this if there's a default case, however. */
4603 if (!thiscase->data.case_stmt.default_label
4604 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4605 && TREE_CODE (index_expr) != INTEGER_CST)
4606 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4608 /* If this is the first label, warn if any insns have been emitted. */
4609 if (thiscase->data.case_stmt.seenlabel == 0)
4612 for (insn = get_last_insn ();
4613 insn != case_stack->data.case_stmt.start;
4614 insn = PREV_INSN (insn))
4615 if (GET_CODE (insn) != NOTE
4616 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4618 warning ("unreachable code at beginning of %s",
4619 case_stack->data.case_stmt.printname);
4624 /* If we don't have a default-label, create one here,
4625 after the body of the switch. */
4626 if (thiscase->data.case_stmt.default_label == 0)
4628 thiscase->data.case_stmt.default_label
4629 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4630 expand_label (thiscase->data.case_stmt.default_label);
4632 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4634 before_case = get_last_insn ();
4636 /* Simplify the case-list before we count it. */
4637 group_case_nodes (thiscase->data.case_stmt.case_list);
4639 /* Get upper and lower bounds of case values.
4640 Also convert all the case values to the index expr's data type. */
4643 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4645 /* Check low and high label values are integers. */
4646 if (TREE_CODE (n->low) != INTEGER_CST)
4648 if (TREE_CODE (n->high) != INTEGER_CST)
4651 n->low = convert (index_type, n->low);
4652 n->high = convert (index_type, n->high);
4654 /* Count the elements and track the largest and smallest
4655 of them (treating them as signed even if they are not). */
4663 if (INT_CST_LT (n->low, minval))
4665 if (INT_CST_LT (maxval, n->high))
4668 /* A range counts double, since it requires two compares. */
4669 if (! tree_int_cst_equal (n->low, n->high))
4673 orig_minval = minval;
4675 /* Compute span of values. */
4677 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4681 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4683 emit_jump (default_label);
4686 /* If range of values is much bigger than number of values,
4687 make a sequence of conditional branches instead of a dispatch.
4688 If the switch-index is a constant, do it this way
4689 because we can optimize it. */
4691 #ifndef CASE_VALUES_THRESHOLD
4693 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4695 /* If machine does not have a case insn that compares the
4696 bounds, this means extra overhead for dispatch tables
4697 which raises the threshold for using them. */
4698 #define CASE_VALUES_THRESHOLD 5
4699 #endif /* HAVE_casesi */
4700 #endif /* CASE_VALUES_THRESHOLD */
4702 else if (TREE_INT_CST_HIGH (range) != 0
4703 || count < CASE_VALUES_THRESHOLD
4704 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4706 || TREE_CODE (index_expr) == INTEGER_CST
4707 /* These will reduce to a constant. */
4708 || (TREE_CODE (index_expr) == CALL_EXPR
4709 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4710 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4711 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4712 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4713 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4715 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4717 /* If the index is a short or char that we do not have
4718 an insn to handle comparisons directly, convert it to
4719 a full integer now, rather than letting each comparison
4720 generate the conversion. */
4722 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4723 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4724 == CODE_FOR_nothing))
4726 enum machine_mode wider_mode;
4727 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4728 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4729 if (cmp_optab->handlers[(int) wider_mode].insn_code
4730 != CODE_FOR_nothing)
4732 index = convert_to_mode (wider_mode, index, unsignedp);
4738 do_pending_stack_adjust ();
4740 index = protect_from_queue (index, 0);
4741 if (GET_CODE (index) == MEM)
4742 index = copy_to_reg (index);
4743 if (GET_CODE (index) == CONST_INT
4744 || TREE_CODE (index_expr) == INTEGER_CST)
4746 /* Make a tree node with the proper constant value
4747 if we don't already have one. */
4748 if (TREE_CODE (index_expr) != INTEGER_CST)
4751 = build_int_2 (INTVAL (index),
4752 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4753 index_expr = convert (index_type, index_expr);
4756 /* For constant index expressions we need only
4757 issue a unconditional branch to the appropriate
4758 target code. The job of removing any unreachable
4759 code is left to the optimisation phase if the
4760 "-O" option is specified. */
4761 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4762 if (! tree_int_cst_lt (index_expr, n->low)
4763 && ! tree_int_cst_lt (n->high, index_expr))
4767 emit_jump (label_rtx (n->code_label));
4769 emit_jump (default_label);
4773 /* If the index expression is not constant we generate
4774 a binary decision tree to select the appropriate
4775 target code. This is done as follows:
4777 The list of cases is rearranged into a binary tree,
4778 nearly optimal assuming equal probability for each case.
4780 The tree is transformed into RTL, eliminating
4781 redundant test conditions at the same time.
4783 If program flow could reach the end of the
4784 decision tree an unconditional jump to the
4785 default code is emitted. */
4788 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4789 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4790 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4792 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4793 default_label, index_type);
4794 emit_jump_if_reachable (default_label);
4803 enum machine_mode index_mode = SImode;
4804 int index_bits = GET_MODE_BITSIZE (index_mode);
4806 enum machine_mode op_mode;
4808 /* Convert the index to SImode. */
4809 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4810 > GET_MODE_BITSIZE (index_mode))
4812 enum machine_mode omode = TYPE_MODE (index_type);
4813 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4815 /* We must handle the endpoints in the original mode. */
4816 index_expr = build (MINUS_EXPR, index_type,
4817 index_expr, minval);
4818 minval = integer_zero_node;
4819 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4820 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4821 emit_jump_insn (gen_bltu (default_label));
4822 /* Now we can safely truncate. */
4823 index = convert_to_mode (index_mode, index, 0);
4827 if (TYPE_MODE (index_type) != index_mode)
4829 index_expr = convert (type_for_size (index_bits, 0),
4831 index_type = TREE_TYPE (index_expr);
4834 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4837 index = protect_from_queue (index, 0);
4838 do_pending_stack_adjust ();
4840 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4841 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4843 index = copy_to_mode_reg (op_mode, index);
4845 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4847 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4848 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4850 op1 = copy_to_mode_reg (op_mode, op1);
4852 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4854 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4855 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4857 op2 = copy_to_mode_reg (op_mode, op2);
4859 emit_jump_insn (gen_casesi (index, op1, op2,
4860 table_label, default_label));
4864 #ifdef HAVE_tablejump
4865 if (! win && HAVE_tablejump)
4867 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4868 fold (build (MINUS_EXPR, index_type,
4869 index_expr, minval)));
4870 index_type = TREE_TYPE (index_expr);
4871 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4873 index = protect_from_queue (index, 0);
4874 do_pending_stack_adjust ();
4876 do_tablejump (index, TYPE_MODE (index_type),
4877 expand_expr (range, NULL_RTX, VOIDmode, 0),
4878 table_label, default_label);
4885 /* Get table of labels to jump to, in order of case index. */
4887 ncases = TREE_INT_CST_LOW (range) + 1;
4888 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4889 bzero ((char *) labelvec, ncases * sizeof (rtx));
4891 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4893 register HOST_WIDE_INT i
4894 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4899 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4900 if (i + TREE_INT_CST_LOW (orig_minval)
4901 == TREE_INT_CST_LOW (n->high))
4907 /* Fill in the gaps with the default. */
4908 for (i = 0; i < ncases; i++)
4909 if (labelvec[i] == 0)
4910 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4912 /* Output the table */
4913 emit_label (table_label);
4915 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
4916 were an expression, instead of an #ifdef/#ifndef. */
4918 #ifdef CASE_VECTOR_PC_RELATIVE
4922 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
4923 gen_rtx (LABEL_REF, Pmode, table_label),
4924 gen_rtvec_v (ncases, labelvec)));
4926 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
4927 gen_rtvec_v (ncases, labelvec)));
4929 /* If the case insn drops through the table,
4930 after the table we must jump to the default-label.
4931 Otherwise record no drop-through after the table. */
4932 #ifdef CASE_DROPS_THROUGH
4933 emit_jump (default_label);
4939 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
4940 reorder_insns (before_case, get_last_insn (),
4941 thiscase->data.case_stmt.start);
4944 if (thiscase->exit_label)
4945 emit_label (thiscase->exit_label);
4947 POPSTACK (case_stack);
4953 /* Terminate a case statement. EXPR is the original index
4957 bc_expand_end_case (expr)
4960 struct nesting *thiscase = case_stack;
4961 enum bytecode_opcode opcode;
4962 struct bc_label *jump_label;
4963 struct case_node *c;
4965 bc_emit_bytecode (jump);
4966 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
4968 #ifdef DEBUG_PRINT_CODE
4969 fputc ('\n', stderr);
4972 /* Now that the size of the jump table is known, emit the actual
4973 indexed jump instruction. */
4974 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
4976 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
4977 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
4978 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
4980 bc_emit_bytecode (opcode);
4982 /* Now emit the case instructions literal arguments, in order.
4983 In addition to the value on the stack, it uses:
4984 1. The address of the jump table.
4985 2. The size of the jump table.
4986 3. The default label. */
4988 jump_label = bc_get_bytecode_label ();
4989 bc_emit_bytecode_labelref (jump_label);
4990 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
4991 sizeof thiscase->data.case_stmt.num_ranges);
4993 if (thiscase->data.case_stmt.default_label)
4994 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
4996 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
4998 /* Output the jump table. */
5000 bc_align_bytecode (3 /* PTR_ALIGN */);
5001 bc_emit_bytecode_labeldef (jump_label);
5003 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5004 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5006 opcode = TREE_INT_CST_LOW (c->low);
5007 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5009 opcode = TREE_INT_CST_LOW (c->high);
5010 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5012 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5015 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5016 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5018 bc_emit_bytecode_DI_const (c->low);
5019 bc_emit_bytecode_DI_const (c->high);
5021 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5028 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5030 /* Possibly issue enumeration warnings. */
5032 if (!thiscase->data.case_stmt.default_label
5033 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5034 && TREE_CODE (expr) != INTEGER_CST
5036 check_for_full_enumeration_handling (TREE_TYPE (expr));
5039 #ifdef DEBUG_PRINT_CODE
5040 fputc ('\n', stderr);
5043 POPSTACK (case_stack);
5047 /* Return unique bytecode ID. */
5052 static int bc_uid = 0;
5057 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5060 do_jump_if_equal (op1, op2, label, unsignedp)
5061 rtx op1, op2, label;
5064 if (GET_CODE (op1) == CONST_INT
5065 && GET_CODE (op2) == CONST_INT)
5067 if (INTVAL (op1) == INTVAL (op2))
5072 enum machine_mode mode = GET_MODE (op1);
5073 if (mode == VOIDmode)
5074 mode = GET_MODE (op2);
5075 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5076 emit_jump_insn (gen_beq (label));
5080 /* Not all case values are encountered equally. This function
5081 uses a heuristic to weight case labels, in cases where that
5082 looks like a reasonable thing to do.
5084 Right now, all we try to guess is text, and we establish the
5087 chars above space: 16
5096 If we find any cases in the switch that are not either -1 or in the range
5097 of valid ASCII characters, or are control characters other than those
5098 commonly used with "\", don't treat this switch scanning text.
5100 Return 1 if these nodes are suitable for cost estimation, otherwise
5104 estimate_case_costs (node)
5107 tree min_ascii = build_int_2 (-1, -1);
5108 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5112 /* If we haven't already made the cost table, make it now. Note that the
5113 lower bound of the table is -1, not zero. */
5115 if (cost_table == NULL)
5117 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5118 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5120 for (i = 0; i < 128; i++)
5124 else if (ispunct (i))
5126 else if (iscntrl (i))
5130 cost_table[' '] = 8;
5131 cost_table['\t'] = 4;
5132 cost_table['\0'] = 4;
5133 cost_table['\n'] = 2;
5134 cost_table['\f'] = 1;
5135 cost_table['\v'] = 1;
5136 cost_table['\b'] = 1;
5139 /* See if all the case expressions look like text. It is text if the
5140 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5141 as signed arithmetic since we don't want to ever access cost_table with a
5142 value less than -1. Also check that none of the constants in a range
5143 are strange control characters. */
5145 for (n = node; n; n = n->right)
5147 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5150 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5151 if (cost_table[i] < 0)
5155 /* All interesting values are within the range of interesting
5156 ASCII characters. */
5160 /* Scan an ordered list of case nodes
5161 combining those with consecutive values or ranges.
5163 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5166 group_case_nodes (head)
5169 case_node_ptr node = head;
5173 rtx lb = next_real_insn (label_rtx (node->code_label));
5174 case_node_ptr np = node;
5176 /* Try to group the successors of NODE with NODE. */
5177 while (((np = np->right) != 0)
5178 /* Do they jump to the same place? */
5179 && next_real_insn (label_rtx (np->code_label)) == lb
5180 /* Are their ranges consecutive? */
5181 && tree_int_cst_equal (np->low,
5182 fold (build (PLUS_EXPR,
5183 TREE_TYPE (node->high),
5186 /* An overflow is not consecutive. */
5187 && tree_int_cst_lt (node->high,
5188 fold (build (PLUS_EXPR,
5189 TREE_TYPE (node->high),
5191 integer_one_node))))
5193 node->high = np->high;
5195 /* NP is the first node after NODE which can't be grouped with it.
5196 Delete the nodes in between, and move on to that node. */
5202 /* Take an ordered list of case nodes
5203 and transform them into a near optimal binary tree,
5204 on the assumption that any target code selection value is as
5205 likely as any other.
5207 The transformation is performed by splitting the ordered
5208 list into two equal sections plus a pivot. The parts are
5209 then attached to the pivot as left and right branches. Each
5210 branch is is then transformed recursively. */
5213 balance_case_nodes (head, parent)
5214 case_node_ptr *head;
5215 case_node_ptr parent;
5217 register case_node_ptr np;
5225 register case_node_ptr *npp;
5228 /* Count the number of entries on branch. Also count the ranges. */
5232 if (!tree_int_cst_equal (np->low, np->high))
5236 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5240 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5248 /* Split this list if it is long enough for that to help. */
5253 /* Find the place in the list that bisects the list's total cost,
5254 Here I gets half the total cost. */
5259 /* Skip nodes while their cost does not reach that amount. */
5260 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5261 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5262 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5265 npp = &(*npp)->right;
5270 /* Leave this branch lopsided, but optimize left-hand
5271 side and fill in `parent' fields for right-hand side. */
5273 np->parent = parent;
5274 balance_case_nodes (&np->left, np);
5275 for (; np->right; np = np->right)
5276 np->right->parent = np;
5280 /* If there are just three nodes, split at the middle one. */
5282 npp = &(*npp)->right;
5285 /* Find the place in the list that bisects the list's total cost,
5286 where ranges count as 2.
5287 Here I gets half the total cost. */
5288 i = (i + ranges + 1) / 2;
5291 /* Skip nodes while their cost does not reach that amount. */
5292 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5297 npp = &(*npp)->right;
5302 np->parent = parent;
5305 /* Optimize each of the two split parts. */
5306 balance_case_nodes (&np->left, np);
5307 balance_case_nodes (&np->right, np);
5311 /* Else leave this branch as one level,
5312 but fill in `parent' fields. */
5314 np->parent = parent;
5315 for (; np->right; np = np->right)
5316 np->right->parent = np;
5321 /* Search the parent sections of the case node tree
5322 to see if a test for the lower bound of NODE would be redundant.
5323 INDEX_TYPE is the type of the index expression.
5325 The instructions to generate the case decision tree are
5326 output in the same order as nodes are processed so it is
5327 known that if a parent node checks the range of the current
5328 node minus one that the current node is bounded at its lower
5329 span. Thus the test would be redundant. */
5332 node_has_low_bound (node, index_type)
5337 case_node_ptr pnode;
5339 /* If the lower bound of this node is the lowest value in the index type,
5340 we need not test it. */
5342 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5345 /* If this node has a left branch, the value at the left must be less
5346 than that at this node, so it cannot be bounded at the bottom and
5347 we need not bother testing any further. */
5352 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5353 node->low, integer_one_node));
5355 /* If the subtraction above overflowed, we can't verify anything.
5356 Otherwise, look for a parent that tests our value - 1. */
5358 if (! tree_int_cst_lt (low_minus_one, node->low))
5361 for (pnode = node->parent; pnode; pnode = pnode->parent)
5362 if (tree_int_cst_equal (low_minus_one, pnode->high))
5368 /* Search the parent sections of the case node tree
5369 to see if a test for the upper bound of NODE would be redundant.
5370 INDEX_TYPE is the type of the index expression.
5372 The instructions to generate the case decision tree are
5373 output in the same order as nodes are processed so it is
5374 known that if a parent node checks the range of the current
5375 node plus one that the current node is bounded at its upper
5376 span. Thus the test would be redundant. */
5379 node_has_high_bound (node, index_type)
5384 case_node_ptr pnode;
5386 /* If the upper bound of this node is the highest value in the type
5387 of the index expression, we need not test against it. */
5389 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5392 /* If this node has a right branch, the value at the right must be greater
5393 than that at this node, so it cannot be bounded at the top and
5394 we need not bother testing any further. */
5399 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5400 node->high, integer_one_node));
5402 /* If the addition above overflowed, we can't verify anything.
5403 Otherwise, look for a parent that tests our value + 1. */
5405 if (! tree_int_cst_lt (node->high, high_plus_one))
5408 for (pnode = node->parent; pnode; pnode = pnode->parent)
5409 if (tree_int_cst_equal (high_plus_one, pnode->low))
5415 /* Search the parent sections of the
5416 case node tree to see if both tests for the upper and lower
5417 bounds of NODE would be redundant. */
5420 node_is_bounded (node, index_type)
5424 return (node_has_low_bound (node, index_type)
5425 && node_has_high_bound (node, index_type));
5428 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5431 emit_jump_if_reachable (label)
5434 if (GET_CODE (get_last_insn ()) != BARRIER)
5438 /* Emit step-by-step code to select a case for the value of INDEX.
5439 The thus generated decision tree follows the form of the
5440 case-node binary tree NODE, whose nodes represent test conditions.
5441 INDEX_TYPE is the type of the index of the switch.
5443 Care is taken to prune redundant tests from the decision tree
5444 by detecting any boundary conditions already checked by
5445 emitted rtx. (See node_has_high_bound, node_has_low_bound
5446 and node_is_bounded, above.)
5448 Where the test conditions can be shown to be redundant we emit
5449 an unconditional jump to the target code. As a further
5450 optimization, the subordinates of a tree node are examined to
5451 check for bounded nodes. In this case conditional and/or
5452 unconditional jumps as a result of the boundary check for the
5453 current node are arranged to target the subordinates associated
5454 code for out of bound conditions on the current node node.
5456 We can assume that when control reaches the code generated here,
5457 the index value has already been compared with the parents
5458 of this node, and determined to be on the same side of each parent
5459 as this node is. Thus, if this node tests for the value 51,
5460 and a parent tested for 52, we don't need to consider
5461 the possibility of a value greater than 51. If another parent
5462 tests for the value 50, then this node need not test anything. */
5465 emit_case_nodes (index, node, default_label, index_type)
5471 /* If INDEX has an unsigned type, we must make unsigned branches. */
5472 int unsignedp = TREE_UNSIGNED (index_type);
5473 typedef rtx rtx_function ();
5474 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5475 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5476 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5477 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5478 enum machine_mode mode = GET_MODE (index);
5480 /* See if our parents have already tested everything for us.
5481 If they have, emit an unconditional jump for this node. */
5482 if (node_is_bounded (node, index_type))
5483 emit_jump (label_rtx (node->code_label));
5485 else if (tree_int_cst_equal (node->low, node->high))
5487 /* Node is single valued. First see if the index expression matches
5488 this node and then check our children, if any. */
5490 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5491 label_rtx (node->code_label), unsignedp);
5493 if (node->right != 0 && node->left != 0)
5495 /* This node has children on both sides.
5496 Dispatch to one side or the other
5497 by comparing the index value with this node's value.
5498 If one subtree is bounded, check that one first,
5499 so we can avoid real branches in the tree. */
5501 if (node_is_bounded (node->right, index_type))
5503 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5505 GT, NULL_RTX, mode, unsignedp, 0);
5507 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5508 emit_case_nodes (index, node->left, default_label, index_type);
5511 else if (node_is_bounded (node->left, index_type))
5513 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5515 LT, NULL_RTX, mode, unsignedp, 0);
5516 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5517 emit_case_nodes (index, node->right, default_label, index_type);
5522 /* Neither node is bounded. First distinguish the two sides;
5523 then emit the code for one side at a time. */
5526 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5528 /* See if the value is on the right. */
5529 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5531 GT, NULL_RTX, mode, unsignedp, 0);
5532 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5534 /* Value must be on the left.
5535 Handle the left-hand subtree. */
5536 emit_case_nodes (index, node->left, default_label, index_type);
5537 /* If left-hand subtree does nothing,
5539 emit_jump_if_reachable (default_label);
5541 /* Code branches here for the right-hand subtree. */
5542 expand_label (test_label);
5543 emit_case_nodes (index, node->right, default_label, index_type);
5547 else if (node->right != 0 && node->left == 0)
5549 /* Here we have a right child but no left so we issue conditional
5550 branch to default and process the right child.
5552 Omit the conditional branch to default if we it avoid only one
5553 right child; it costs too much space to save so little time. */
5555 if (node->right->right || node->right->left
5556 || !tree_int_cst_equal (node->right->low, node->right->high))
5558 if (!node_has_low_bound (node, index_type))
5560 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5562 LT, NULL_RTX, mode, unsignedp, 0);
5563 emit_jump_insn ((*gen_blt_pat) (default_label));
5566 emit_case_nodes (index, node->right, default_label, index_type);
5569 /* We cannot process node->right normally
5570 since we haven't ruled out the numbers less than
5571 this node's value. So handle node->right explicitly. */
5572 do_jump_if_equal (index,
5573 expand_expr (node->right->low, NULL_RTX,
5575 label_rtx (node->right->code_label), unsignedp);
5578 else if (node->right == 0 && node->left != 0)
5580 /* Just one subtree, on the left. */
5582 #if 0 /* The following code and comment were formerly part
5583 of the condition here, but they didn't work
5584 and I don't understand what the idea was. -- rms. */
5585 /* If our "most probable entry" is less probable
5586 than the default label, emit a jump to
5587 the default label using condition codes
5588 already lying around. With no right branch,
5589 a branch-greater-than will get us to the default
5592 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5595 if (node->left->left || node->left->right
5596 || !tree_int_cst_equal (node->left->low, node->left->high))
5598 if (!node_has_high_bound (node, index_type))
5600 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5602 GT, NULL_RTX, mode, unsignedp, 0);
5603 emit_jump_insn ((*gen_bgt_pat) (default_label));
5606 emit_case_nodes (index, node->left, default_label, index_type);
5609 /* We cannot process node->left normally
5610 since we haven't ruled out the numbers less than
5611 this node's value. So handle node->left explicitly. */
5612 do_jump_if_equal (index,
5613 expand_expr (node->left->low, NULL_RTX,
5615 label_rtx (node->left->code_label), unsignedp);
5620 /* Node is a range. These cases are very similar to those for a single
5621 value, except that we do not start by testing whether this node
5622 is the one to branch to. */
5624 if (node->right != 0 && node->left != 0)
5626 /* Node has subtrees on both sides.
5627 If the right-hand subtree is bounded,
5628 test for it first, since we can go straight there.
5629 Otherwise, we need to make a branch in the control structure,
5630 then handle the two subtrees. */
5631 tree test_label = 0;
5633 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5635 GT, NULL_RTX, mode, unsignedp, 0);
5637 if (node_is_bounded (node->right, index_type))
5638 /* Right hand node is fully bounded so we can eliminate any
5639 testing and branch directly to the target code. */
5640 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5643 /* Right hand node requires testing.
5644 Branch to a label where we will handle it later. */
5646 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5647 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5650 /* Value belongs to this node or to the left-hand subtree. */
5652 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5653 GE, NULL_RTX, mode, unsignedp, 0);
5654 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5656 /* Handle the left-hand subtree. */
5657 emit_case_nodes (index, node->left, default_label, index_type);
5659 /* If right node had to be handled later, do that now. */
5663 /* If the left-hand subtree fell through,
5664 don't let it fall into the right-hand subtree. */
5665 emit_jump_if_reachable (default_label);
5667 expand_label (test_label);
5668 emit_case_nodes (index, node->right, default_label, index_type);
5672 else if (node->right != 0 && node->left == 0)
5674 /* Deal with values to the left of this node,
5675 if they are possible. */
5676 if (!node_has_low_bound (node, index_type))
5678 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5680 LT, NULL_RTX, mode, unsignedp, 0);
5681 emit_jump_insn ((*gen_blt_pat) (default_label));
5684 /* Value belongs to this node or to the right-hand subtree. */
5686 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5688 LE, NULL_RTX, mode, unsignedp, 0);
5689 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5691 emit_case_nodes (index, node->right, default_label, index_type);
5694 else if (node->right == 0 && node->left != 0)
5696 /* Deal with values to the right of this node,
5697 if they are possible. */
5698 if (!node_has_high_bound (node, index_type))
5700 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5702 GT, NULL_RTX, mode, unsignedp, 0);
5703 emit_jump_insn ((*gen_bgt_pat) (default_label));
5706 /* Value belongs to this node or to the left-hand subtree. */
5708 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5709 GE, NULL_RTX, mode, unsignedp, 0);
5710 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5712 emit_case_nodes (index, node->left, default_label, index_type);
5717 /* Node has no children so we check low and high bounds to remove
5718 redundant tests. Only one of the bounds can exist,
5719 since otherwise this node is bounded--a case tested already. */
5721 if (!node_has_high_bound (node, index_type))
5723 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5725 GT, NULL_RTX, mode, unsignedp, 0);
5726 emit_jump_insn ((*gen_bgt_pat) (default_label));
5729 if (!node_has_low_bound (node, index_type))
5731 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5733 LT, NULL_RTX, mode, unsignedp, 0);
5734 emit_jump_insn ((*gen_blt_pat) (default_label));
5737 emit_jump (label_rtx (node->code_label));
5742 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5743 so that the debugging info will be correct for the unrolled loop. */
5745 /* Indexed by block number, contains a pointer to the N'th block node. */
5747 static tree *block_vector;
5750 find_loop_tree_blocks ()
5752 tree block = DECL_INITIAL (current_function_decl);
5754 /* There first block is for the function body, and does not have
5755 corresponding block notes. Don't include it in the block vector. */
5756 block = BLOCK_SUBBLOCKS (block);
5758 block_vector = identify_blocks (block, get_insns ());
5762 unroll_block_trees ()
5764 tree block = DECL_INITIAL (current_function_decl);
5766 reorder_blocks (block_vector, block, get_insns ());