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));
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);
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);
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), 0);
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 XVECEXP (body, 4, i) /* constraints */
1496 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1497 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1501 /* Protect all the operands from the queue,
1502 now that they have all been evaluated. */
1504 for (i = 0; i < ninputs; i++)
1505 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1507 for (i = 0; i < noutputs; i++)
1508 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1510 /* Now, for each output, construct an rtx
1511 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1512 ARGVEC CONSTRAINTS))
1513 If there is more than one, put them inside a PARALLEL. */
1515 if (noutputs == 1 && nclobbers == 0)
1517 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1518 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1520 else if (noutputs == 0 && nclobbers == 0)
1522 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1523 insn = emit_insn (body);
1529 if (num == 0) num = 1;
1530 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1532 /* For each output operand, store a SET. */
1534 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1536 XVECEXP (body, 0, i)
1537 = gen_rtx (SET, VOIDmode,
1539 gen_rtx (ASM_OPERANDS, VOIDmode,
1540 TREE_STRING_POINTER (string),
1541 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1542 i, argvec, constraints,
1544 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1547 /* If there are no outputs (but there are some clobbers)
1548 store the bare ASM_OPERANDS into the PARALLEL. */
1551 XVECEXP (body, 0, i++) = obody;
1553 /* Store (clobber REG) for each clobbered register specified. */
1555 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1557 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1558 int j = decode_reg_name (regname);
1562 if (j == -3) /* `cc', which is not a register */
1565 if (j == -4) /* `memory', don't cache memory across asm */
1567 XVECEXP (body, 0, i++)
1568 = gen_rtx (CLOBBER, VOIDmode,
1569 gen_rtx (MEM, BLKmode,
1570 gen_rtx (SCRATCH, VOIDmode, 0)));
1574 /* Ignore unknown register, error already signalled. */
1577 /* Use QImode since that's guaranteed to clobber just one reg. */
1578 XVECEXP (body, 0, i++)
1579 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1582 insn = emit_insn (body);
1588 /* Generate RTL to evaluate the expression EXP
1589 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1592 expand_expr_stmt (exp)
1595 if (output_bytecode)
1597 int org_stack_depth = stack_depth;
1599 bc_expand_expr (exp);
1601 /* Restore stack depth */
1602 if (stack_depth < org_stack_depth)
1605 bc_emit_instruction (drop);
1607 last_expr_type = TREE_TYPE (exp);
1611 /* If -W, warn about statements with no side effects,
1612 except for an explicit cast to void (e.g. for assert()), and
1613 except inside a ({...}) where they may be useful. */
1614 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1616 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1617 && !(TREE_CODE (exp) == CONVERT_EXPR
1618 && TREE_TYPE (exp) == void_type_node))
1619 warning_with_file_and_line (emit_filename, emit_lineno,
1620 "statement with no effect");
1621 else if (warn_unused)
1622 warn_if_unused_value (exp);
1625 /* If EXP is of function type and we are expanding statements for
1626 value, convert it to pointer-to-function. */
1627 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1628 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1630 last_expr_type = TREE_TYPE (exp);
1631 if (! flag_syntax_only)
1632 last_expr_value = expand_expr (exp,
1633 (expr_stmts_for_value
1634 ? NULL_RTX : const0_rtx),
1637 /* If all we do is reference a volatile value in memory,
1638 copy it to a register to be sure it is actually touched. */
1639 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1640 && TREE_THIS_VOLATILE (exp))
1642 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1644 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1645 copy_to_reg (last_expr_value);
1648 rtx lab = gen_label_rtx ();
1650 /* Compare the value with itself to reference it. */
1651 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1652 expand_expr (TYPE_SIZE (last_expr_type),
1653 NULL_RTX, VOIDmode, 0),
1655 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1656 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1661 /* If this expression is part of a ({...}) and is in memory, we may have
1662 to preserve temporaries. */
1663 preserve_temp_slots (last_expr_value);
1665 /* Free any temporaries used to evaluate this expression. Any temporary
1666 used as a result of this expression will already have been preserved
1673 /* Warn if EXP contains any computations whose results are not used.
1674 Return 1 if a warning is printed; 0 otherwise. */
1677 warn_if_unused_value (exp)
1680 if (TREE_USED (exp))
1683 switch (TREE_CODE (exp))
1685 case PREINCREMENT_EXPR:
1686 case POSTINCREMENT_EXPR:
1687 case PREDECREMENT_EXPR:
1688 case POSTDECREMENT_EXPR:
1693 case METHOD_CALL_EXPR:
1695 case WITH_CLEANUP_EXPR:
1697 /* We don't warn about COND_EXPR because it may be a useful
1698 construct if either arm contains a side effect. */
1703 /* For a binding, warn if no side effect within it. */
1704 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1706 case TRUTH_ORIF_EXPR:
1707 case TRUTH_ANDIF_EXPR:
1708 /* In && or ||, warn if 2nd operand has no side effect. */
1709 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1712 if (TREE_NO_UNUSED_WARNING (exp))
1714 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1716 /* Let people do `(foo (), 0)' without a warning. */
1717 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1719 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1723 case NON_LVALUE_EXPR:
1724 /* Don't warn about values cast to void. */
1725 if (TREE_TYPE (exp) == void_type_node)
1727 /* Don't warn about conversions not explicit in the user's program. */
1728 if (TREE_NO_UNUSED_WARNING (exp))
1730 /* Assignment to a cast usually results in a cast of a modify.
1731 Don't complain about that. There can be an arbitrary number of
1732 casts before the modify, so we must loop until we find the first
1733 non-cast expression and then test to see if that is a modify. */
1735 tree tem = TREE_OPERAND (exp, 0);
1737 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1738 tem = TREE_OPERAND (tem, 0);
1740 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR)
1743 /* ... fall through ... */
1746 /* Referencing a volatile value is a side effect, so don't warn. */
1747 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1748 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1749 && TREE_THIS_VOLATILE (exp))
1751 warning_with_file_and_line (emit_filename, emit_lineno,
1752 "value computed is not used");
1757 /* Clear out the memory of the last expression evaluated. */
1765 /* Begin a statement which will return a value.
1766 Return the RTL_EXPR for this statement expr.
1767 The caller must save that value and pass it to expand_end_stmt_expr. */
1770 expand_start_stmt_expr ()
1775 /* When generating bytecode just note down the stack depth */
1776 if (output_bytecode)
1777 return (build_int_2 (stack_depth, 0));
1779 /* Make the RTL_EXPR node temporary, not momentary,
1780 so that rtl_expr_chain doesn't become garbage. */
1781 momentary = suspend_momentary ();
1782 t = make_node (RTL_EXPR);
1783 resume_momentary (momentary);
1784 start_sequence_for_rtl_expr (t);
1786 expr_stmts_for_value++;
1790 /* Restore the previous state at the end of a statement that returns a value.
1791 Returns a tree node representing the statement's value and the
1792 insns to compute the value.
1794 The nodes of that expression have been freed by now, so we cannot use them.
1795 But we don't want to do that anyway; the expression has already been
1796 evaluated and now we just want to use the value. So generate a RTL_EXPR
1797 with the proper type and RTL value.
1799 If the last substatement was not an expression,
1800 return something with type `void'. */
1803 expand_end_stmt_expr (t)
1806 if (output_bytecode)
1812 /* At this point, all expressions have been evaluated in order.
1813 However, all expression values have been popped when evaluated,
1814 which means we have to recover the last expression value. This is
1815 the last value removed by means of a `drop' instruction. Instead
1816 of adding code to inhibit dropping the last expression value, it
1817 is here recovered by undoing the `drop'. Since `drop' is
1818 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1821 bc_adjust_stack (-1);
1823 if (!last_expr_type)
1824 last_expr_type = void_type_node;
1826 t = make_node (RTL_EXPR);
1827 TREE_TYPE (t) = last_expr_type;
1828 RTL_EXPR_RTL (t) = NULL;
1829 RTL_EXPR_SEQUENCE (t) = NULL;
1831 /* Don't consider deleting this expr or containing exprs at tree level. */
1832 TREE_THIS_VOLATILE (t) = 1;
1840 if (last_expr_type == 0)
1842 last_expr_type = void_type_node;
1843 last_expr_value = const0_rtx;
1845 else if (last_expr_value == 0)
1846 /* There are some cases where this can happen, such as when the
1847 statement is void type. */
1848 last_expr_value = const0_rtx;
1849 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1850 /* Remove any possible QUEUED. */
1851 last_expr_value = protect_from_queue (last_expr_value, 0);
1855 TREE_TYPE (t) = last_expr_type;
1856 RTL_EXPR_RTL (t) = last_expr_value;
1857 RTL_EXPR_SEQUENCE (t) = get_insns ();
1859 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1863 /* Don't consider deleting this expr or containing exprs at tree level. */
1864 TREE_SIDE_EFFECTS (t) = 1;
1865 /* Propagate volatility of the actual RTL expr. */
1866 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1869 expr_stmts_for_value--;
1874 /* Generate RTL for the start of an if-then. COND is the expression
1875 whose truth should be tested.
1877 If EXITFLAG is nonzero, this conditional is visible to
1878 `exit_something'. */
1881 expand_start_cond (cond, exitflag)
1885 struct nesting *thiscond = ALLOC_NESTING ();
1887 /* Make an entry on cond_stack for the cond we are entering. */
1889 thiscond->next = cond_stack;
1890 thiscond->all = nesting_stack;
1891 thiscond->depth = ++nesting_depth;
1892 thiscond->data.cond.next_label = gen_label_rtx ();
1893 /* Before we encounter an `else', we don't need a separate exit label
1894 unless there are supposed to be exit statements
1895 to exit this conditional. */
1896 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1897 thiscond->data.cond.endif_label = thiscond->exit_label;
1898 cond_stack = thiscond;
1899 nesting_stack = thiscond;
1901 if (output_bytecode)
1902 bc_expand_start_cond (cond, exitflag);
1904 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1907 /* Generate RTL between then-clause and the elseif-clause
1908 of an if-then-elseif-.... */
1911 expand_start_elseif (cond)
1914 if (cond_stack->data.cond.endif_label == 0)
1915 cond_stack->data.cond.endif_label = gen_label_rtx ();
1916 emit_jump (cond_stack->data.cond.endif_label);
1917 emit_label (cond_stack->data.cond.next_label);
1918 cond_stack->data.cond.next_label = gen_label_rtx ();
1919 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1922 /* Generate RTL between the then-clause and the else-clause
1923 of an if-then-else. */
1926 expand_start_else ()
1928 if (cond_stack->data.cond.endif_label == 0)
1929 cond_stack->data.cond.endif_label = gen_label_rtx ();
1931 if (output_bytecode)
1933 bc_expand_start_else ();
1937 emit_jump (cond_stack->data.cond.endif_label);
1938 emit_label (cond_stack->data.cond.next_label);
1939 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
1942 /* After calling expand_start_else, turn this "else" into an "else if"
1943 by providing another condition. */
1946 expand_elseif (cond)
1949 cond_stack->data.cond.next_label = gen_label_rtx ();
1950 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1953 /* Generate RTL for the end of an if-then.
1954 Pop the record for it off of cond_stack. */
1959 struct nesting *thiscond = cond_stack;
1961 if (output_bytecode)
1962 bc_expand_end_cond ();
1965 do_pending_stack_adjust ();
1966 if (thiscond->data.cond.next_label)
1967 emit_label (thiscond->data.cond.next_label);
1968 if (thiscond->data.cond.endif_label)
1969 emit_label (thiscond->data.cond.endif_label);
1972 POPSTACK (cond_stack);
1977 /* Generate code for the start of an if-then. COND is the expression
1978 whose truth is to be tested; if EXITFLAG is nonzero this conditional
1979 is to be visible to exit_something. It is assumed that the caller
1980 has pushed the previous context on the cond stack. */
1983 bc_expand_start_cond (cond, exitflag)
1987 struct nesting *thiscond = cond_stack;
1989 thiscond->data.case_stmt.nominal_type = cond;
1991 thiscond->exit_label = gen_label_rtx ();
1992 bc_expand_expr (cond);
1993 bc_emit_bytecode (xjumpifnot);
1994 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
1996 #ifdef DEBUG_PRINT_CODE
1997 fputc ('\n', stderr);
2001 /* Generate the label for the end of an if with
2005 bc_expand_end_cond ()
2007 struct nesting *thiscond = cond_stack;
2009 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2012 /* Generate code for the start of the else- clause of
2016 bc_expand_start_else ()
2018 struct nesting *thiscond = cond_stack;
2020 thiscond->data.cond.endif_label = thiscond->exit_label;
2021 thiscond->exit_label = gen_label_rtx ();
2022 bc_emit_bytecode (jump);
2023 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2025 #ifdef DEBUG_PRINT_CODE
2026 fputc ('\n', stderr);
2029 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2032 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2033 loop should be exited by `exit_something'. This is a loop for which
2034 `expand_continue' will jump to the top of the loop.
2036 Make an entry on loop_stack to record the labels associated with
2040 expand_start_loop (exit_flag)
2043 register struct nesting *thisloop = ALLOC_NESTING ();
2045 /* Make an entry on loop_stack for the loop we are entering. */
2047 thisloop->next = loop_stack;
2048 thisloop->all = nesting_stack;
2049 thisloop->depth = ++nesting_depth;
2050 thisloop->data.loop.start_label = gen_label_rtx ();
2051 thisloop->data.loop.end_label = gen_label_rtx ();
2052 thisloop->data.loop.alt_end_label = 0;
2053 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2054 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2055 loop_stack = thisloop;
2056 nesting_stack = thisloop;
2058 if (output_bytecode)
2060 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2064 do_pending_stack_adjust ();
2066 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2067 emit_label (thisloop->data.loop.start_label);
2072 /* Like expand_start_loop but for a loop where the continuation point
2073 (for expand_continue_loop) will be specified explicitly. */
2076 expand_start_loop_continue_elsewhere (exit_flag)
2079 struct nesting *thisloop = expand_start_loop (exit_flag);
2080 loop_stack->data.loop.continue_label = gen_label_rtx ();
2084 /* Specify the continuation point for a loop started with
2085 expand_start_loop_continue_elsewhere.
2086 Use this at the point in the code to which a continue statement
2090 expand_loop_continue_here ()
2092 if (output_bytecode)
2094 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2097 do_pending_stack_adjust ();
2098 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2099 emit_label (loop_stack->data.loop.continue_label);
2105 bc_expand_end_loop ()
2107 struct nesting *thisloop = loop_stack;
2109 bc_emit_bytecode (jump);
2110 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2112 #ifdef DEBUG_PRINT_CODE
2113 fputc ('\n', stderr);
2116 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2117 POPSTACK (loop_stack);
2122 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2123 Pop the block off of loop_stack. */
2129 register rtx start_label;
2130 rtx last_test_insn = 0;
2133 if (output_bytecode)
2135 bc_expand_end_loop ();
2139 insn = get_last_insn ();
2140 start_label = loop_stack->data.loop.start_label;
2142 /* Mark the continue-point at the top of the loop if none elsewhere. */
2143 if (start_label == loop_stack->data.loop.continue_label)
2144 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2146 do_pending_stack_adjust ();
2148 /* If optimizing, perhaps reorder the loop. If the loop
2149 starts with a conditional exit, roll that to the end
2150 where it will optimize together with the jump back.
2152 We look for the last conditional branch to the exit that we encounter
2153 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2154 branch to the exit first, use it.
2156 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2157 because moving them is not valid. */
2161 ! (GET_CODE (insn) == JUMP_INSN
2162 && GET_CODE (PATTERN (insn)) == SET
2163 && SET_DEST (PATTERN (insn)) == pc_rtx
2164 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2166 /* Scan insns from the top of the loop looking for a qualified
2167 conditional exit. */
2168 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2169 insn = NEXT_INSN (insn))
2171 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2174 if (GET_CODE (insn) == NOTE
2175 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2176 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2179 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2182 if (last_test_insn && num_insns > 30)
2185 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2186 && SET_DEST (PATTERN (insn)) == pc_rtx
2187 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2188 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2189 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2190 == loop_stack->data.loop.end_label)
2191 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2192 == loop_stack->data.loop.alt_end_label)))
2193 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2194 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2195 == loop_stack->data.loop.end_label)
2196 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2197 == loop_stack->data.loop.alt_end_label)))))
2198 last_test_insn = insn;
2200 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2201 && GET_CODE (PATTERN (insn)) == SET
2202 && SET_DEST (PATTERN (insn)) == pc_rtx
2203 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2204 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2205 == loop_stack->data.loop.end_label)
2206 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2207 == loop_stack->data.loop.alt_end_label)))
2208 /* Include BARRIER. */
2209 last_test_insn = NEXT_INSN (insn);
2212 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2214 /* We found one. Move everything from there up
2215 to the end of the loop, and add a jump into the loop
2216 to jump to there. */
2217 register rtx newstart_label = gen_label_rtx ();
2218 register rtx start_move = start_label;
2220 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2221 then we want to move this note also. */
2222 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2223 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2224 == NOTE_INSN_LOOP_CONT))
2225 start_move = PREV_INSN (start_move);
2227 emit_label_after (newstart_label, PREV_INSN (start_move));
2228 reorder_insns (start_move, last_test_insn, get_last_insn ());
2229 emit_jump_insn_after (gen_jump (start_label),
2230 PREV_INSN (newstart_label));
2231 emit_barrier_after (PREV_INSN (newstart_label));
2232 start_label = newstart_label;
2236 emit_jump (start_label);
2237 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2238 emit_label (loop_stack->data.loop.end_label);
2240 POPSTACK (loop_stack);
2245 /* Generate a jump to the current loop's continue-point.
2246 This is usually the top of the loop, but may be specified
2247 explicitly elsewhere. If not currently inside a loop,
2248 return 0 and do nothing; caller will print an error message. */
2251 expand_continue_loop (whichloop)
2252 struct nesting *whichloop;
2256 whichloop = loop_stack;
2259 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2264 /* Generate a jump to exit the current loop. If not currently inside a loop,
2265 return 0 and do nothing; caller will print an error message. */
2268 expand_exit_loop (whichloop)
2269 struct nesting *whichloop;
2273 whichloop = loop_stack;
2276 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2280 /* Generate a conditional jump to exit the current loop if COND
2281 evaluates to zero. If not currently inside a loop,
2282 return 0 and do nothing; caller will print an error message. */
2285 expand_exit_loop_if_false (whichloop, cond)
2286 struct nesting *whichloop;
2291 whichloop = loop_stack;
2294 if (output_bytecode)
2296 bc_expand_expr (cond);
2297 bc_expand_goto_internal (xjumpifnot,
2298 BYTECODE_BC_LABEL (whichloop->exit_label),
2303 /* In order to handle fixups, we actually create a conditional jump
2304 around a unconditional branch to exit the loop. If fixups are
2305 necessary, they go before the unconditional branch. */
2307 rtx label = gen_label_rtx ();
2310 do_jump (cond, NULL_RTX, label);
2311 last_insn = get_last_insn ();
2312 if (GET_CODE (last_insn) == CODE_LABEL)
2313 whichloop->data.loop.alt_end_label = last_insn;
2314 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2322 /* Return non-zero if we should preserve sub-expressions as separate
2323 pseudos. We never do so if we aren't optimizing. We always do so
2324 if -fexpensive-optimizations.
2326 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2327 the loop may still be a small one. */
2330 preserve_subexpressions_p ()
2334 if (flag_expensive_optimizations)
2337 if (optimize == 0 || loop_stack == 0)
2340 insn = get_last_insn_anywhere ();
2343 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2344 < n_non_fixed_regs * 3));
2348 /* Generate a jump to exit the current loop, conditional, binding contour
2349 or case statement. Not all such constructs are visible to this function,
2350 only those started with EXIT_FLAG nonzero. Individual languages use
2351 the EXIT_FLAG parameter to control which kinds of constructs you can
2354 If not currently inside anything that can be exited,
2355 return 0 and do nothing; caller will print an error message. */
2358 expand_exit_something ()
2362 for (n = nesting_stack; n; n = n->all)
2363 if (n->exit_label != 0)
2365 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2372 /* Generate RTL to return from the current function, with no value.
2373 (That is, we do not do anything about returning any value.) */
2376 expand_null_return ()
2378 struct nesting *block = block_stack;
2381 if (output_bytecode)
2383 bc_emit_instruction (ret);
2387 /* Does any pending block have cleanups? */
2389 while (block && block->data.block.cleanups == 0)
2390 block = block->next;
2392 /* If yes, use a goto to return, since that runs cleanups. */
2394 expand_null_return_1 (last_insn, block != 0);
2397 /* Generate RTL to return from the current function, with value VAL. */
2400 expand_value_return (val)
2403 struct nesting *block = block_stack;
2404 rtx last_insn = get_last_insn ();
2405 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2407 /* Copy the value to the return location
2408 unless it's already there. */
2410 if (return_reg != val)
2412 #ifdef PROMOTE_FUNCTION_RETURN
2413 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2414 int unsignedp = TREE_UNSIGNED (type);
2415 enum machine_mode mode
2416 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2419 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2420 convert_move (return_reg, val, unsignedp);
2423 emit_move_insn (return_reg, val);
2425 if (GET_CODE (return_reg) == REG
2426 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2427 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2429 /* Does any pending block have cleanups? */
2431 while (block && block->data.block.cleanups == 0)
2432 block = block->next;
2434 /* If yes, use a goto to return, since that runs cleanups.
2435 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2437 expand_null_return_1 (last_insn, block != 0);
2440 /* Output a return with no value. If LAST_INSN is nonzero,
2441 pretend that the return takes place after LAST_INSN.
2442 If USE_GOTO is nonzero then don't use a return instruction;
2443 go to the return label instead. This causes any cleanups
2444 of pending blocks to be executed normally. */
2447 expand_null_return_1 (last_insn, use_goto)
2451 rtx end_label = cleanup_label ? cleanup_label : return_label;
2453 clear_pending_stack_adjust ();
2454 do_pending_stack_adjust ();
2457 /* PCC-struct return always uses an epilogue. */
2458 if (current_function_returns_pcc_struct || use_goto)
2461 end_label = return_label = gen_label_rtx ();
2462 expand_goto_internal (NULL_TREE, end_label, last_insn);
2466 /* Otherwise output a simple return-insn if one is available,
2467 unless it won't do the job. */
2469 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2471 emit_jump_insn (gen_return ());
2477 /* Otherwise jump to the epilogue. */
2478 expand_goto_internal (NULL_TREE, end_label, last_insn);
2481 /* Generate RTL to evaluate the expression RETVAL and return it
2482 from the current function. */
2485 expand_return (retval)
2488 /* If there are any cleanups to be performed, then they will
2489 be inserted following LAST_INSN. It is desirable
2490 that the last_insn, for such purposes, should be the
2491 last insn before computing the return value. Otherwise, cleanups
2492 which call functions can clobber the return value. */
2493 /* ??? rms: I think that is erroneous, because in C++ it would
2494 run destructors on variables that might be used in the subsequent
2495 computation of the return value. */
2497 register rtx val = 0;
2501 struct nesting *block;
2503 /* Bytecode returns are quite simple, just leave the result on the
2504 arithmetic stack. */
2505 if (output_bytecode)
2507 bc_expand_expr (retval);
2508 bc_emit_instruction (ret);
2512 /* If function wants no value, give it none. */
2513 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2515 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2517 expand_null_return ();
2521 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2522 /* This is not sufficient. We also need to watch for cleanups of the
2523 expression we are about to expand. Unfortunately, we cannot know
2524 if it has cleanups until we expand it, and we want to change how we
2525 expand it depending upon if we need cleanups. We can't win. */
2527 cleanups = any_pending_cleanups (1);
2532 if (TREE_CODE (retval) == RESULT_DECL)
2533 retval_rhs = retval;
2534 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2535 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2536 retval_rhs = TREE_OPERAND (retval, 1);
2537 else if (TREE_TYPE (retval) == void_type_node)
2538 /* Recognize tail-recursive call to void function. */
2539 retval_rhs = retval;
2541 retval_rhs = NULL_TREE;
2543 /* Only use `last_insn' if there are cleanups which must be run. */
2544 if (cleanups || cleanup_label != 0)
2545 last_insn = get_last_insn ();
2547 /* Distribute return down conditional expr if either of the sides
2548 may involve tail recursion (see test below). This enhances the number
2549 of tail recursions we see. Don't do this always since it can produce
2550 sub-optimal code in some cases and we distribute assignments into
2551 conditional expressions when it would help. */
2553 if (optimize && retval_rhs != 0
2554 && frame_offset == 0
2555 && TREE_CODE (retval_rhs) == COND_EXPR
2556 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2557 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2559 rtx label = gen_label_rtx ();
2562 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2563 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2564 DECL_RESULT (current_function_decl),
2565 TREE_OPERAND (retval_rhs, 1));
2566 TREE_SIDE_EFFECTS (expr) = 1;
2567 expand_return (expr);
2570 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2571 DECL_RESULT (current_function_decl),
2572 TREE_OPERAND (retval_rhs, 2));
2573 TREE_SIDE_EFFECTS (expr) = 1;
2574 expand_return (expr);
2578 /* For tail-recursive call to current function,
2579 just jump back to the beginning.
2580 It's unsafe if any auto variable in this function
2581 has its address taken; for simplicity,
2582 require stack frame to be empty. */
2583 if (optimize && retval_rhs != 0
2584 && frame_offset == 0
2585 && TREE_CODE (retval_rhs) == CALL_EXPR
2586 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2587 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2588 /* Finish checking validity, and if valid emit code
2589 to set the argument variables for the new call. */
2590 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2591 DECL_ARGUMENTS (current_function_decl)))
2593 if (tail_recursion_label == 0)
2595 tail_recursion_label = gen_label_rtx ();
2596 emit_label_after (tail_recursion_label,
2597 tail_recursion_reentry);
2600 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2605 /* This optimization is safe if there are local cleanups
2606 because expand_null_return takes care of them.
2607 ??? I think it should also be safe when there is a cleanup label,
2608 because expand_null_return takes care of them, too.
2609 Any reason why not? */
2610 if (HAVE_return && cleanup_label == 0
2611 && ! current_function_returns_pcc_struct
2612 && BRANCH_COST <= 1)
2614 /* If this is return x == y; then generate
2615 if (x == y) return 1; else return 0;
2616 if we can do it with explicit return insns and
2617 branches are cheap. */
2619 switch (TREE_CODE (retval_rhs))
2627 case TRUTH_ANDIF_EXPR:
2628 case TRUTH_ORIF_EXPR:
2629 case TRUTH_AND_EXPR:
2631 case TRUTH_NOT_EXPR:
2632 case TRUTH_XOR_EXPR:
2633 op0 = gen_label_rtx ();
2634 jumpifnot (retval_rhs, op0);
2635 expand_value_return (const1_rtx);
2637 expand_value_return (const0_rtx);
2641 #endif /* HAVE_return */
2643 /* If the result is an aggregate that is being returned in one (or more)
2644 registers, load the registers here. The compiler currently can't handle
2645 copying a BLKmode value into registers. We could put this code in a
2646 more general area (for use by everyone instead of just function
2647 call/return), but until this feature is generally usable it is kept here
2648 (and in expand_call). */
2651 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2652 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2655 int big_endian_correction = 0;
2656 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2657 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2658 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2659 rtx result_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2660 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2661 enum machine_mode tmpmode;
2663 /* Structures smaller than a word are aligned to the least significant
2664 byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we
2665 must skip the empty high order bytes when calculating the bit
2667 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
2668 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
2670 for (i = 0; i < n_regs; i++)
2672 rtx reg = gen_reg_rtx (word_mode);
2673 rtx word = operand_subword_force (result_val, i, BLKmode);
2674 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2677 result_pseudos[i] = reg;
2679 /* Clobber REG and move each partword into it. Ensure we don't
2680 go past the end of the structure. Note that the loop below
2681 works because we've already verified that padding and
2682 endianness are compatable. */
2683 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
2686 bitpos < BITS_PER_WORD && bytes > 0;
2687 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
2689 int xbitpos = bitpos + big_endian_correction;
2691 store_bit_field (reg, bitsize, xbitpos, word_mode,
2692 extract_bit_field (word, bitsize, bitpos, 1,
2693 NULL_RTX, word_mode,
2695 bitsize / BITS_PER_UNIT,
2697 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2701 /* Now that the value is in pseudos, copy it to the result reg(s). */
2704 for (i = 0; i < n_regs; i++)
2705 emit_move_insn (gen_rtx (REG, word_mode, REGNO (result_reg) + i),
2708 /* Find the smallest integer mode large enough to hold the
2709 entire structure and use that mode instead of BLKmode
2710 on the USE insn for the return register. */
2711 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2712 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2713 tmpmode != MAX_MACHINE_MODE;
2714 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2716 /* Have we found a large enough mode? */
2717 if (GET_MODE_SIZE (tmpmode) >= bytes)
2721 /* No suitable mode found. */
2722 if (tmpmode == MAX_MACHINE_MODE)
2725 PUT_MODE (result_reg, tmpmode);
2727 expand_value_return (result_reg);
2731 && TREE_TYPE (retval_rhs) != void_type_node
2732 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2734 /* Calculate the return value into a pseudo reg. */
2735 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2737 /* All temporaries have now been used. */
2739 /* Return the calculated value, doing cleanups first. */
2740 expand_value_return (val);
2744 /* No cleanups or no hard reg used;
2745 calculate value into hard return reg. */
2746 expand_expr (retval, const0_rtx, VOIDmode, 0);
2749 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2753 /* Return 1 if the end of the generated RTX is not a barrier.
2754 This means code already compiled can drop through. */
2757 drop_through_at_end_p ()
2759 rtx insn = get_last_insn ();
2760 while (insn && GET_CODE (insn) == NOTE)
2761 insn = PREV_INSN (insn);
2762 return insn && GET_CODE (insn) != BARRIER;
2765 /* Emit code to alter this function's formal parms for a tail-recursive call.
2766 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2767 FORMALS is the chain of decls of formals.
2768 Return 1 if this can be done;
2769 otherwise return 0 and do not emit any code. */
2772 tail_recursion_args (actuals, formals)
2773 tree actuals, formals;
2775 register tree a = actuals, f = formals;
2777 register rtx *argvec;
2779 /* Check that number and types of actuals are compatible
2780 with the formals. This is not always true in valid C code.
2781 Also check that no formal needs to be addressable
2782 and that all formals are scalars. */
2784 /* Also count the args. */
2786 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2788 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2790 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2793 if (a != 0 || f != 0)
2796 /* Compute all the actuals. */
2798 argvec = (rtx *) alloca (i * sizeof (rtx));
2800 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2801 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2803 /* Find which actual values refer to current values of previous formals.
2804 Copy each of them now, before any formal is changed. */
2806 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2810 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2811 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2812 { copy = 1; break; }
2814 argvec[i] = copy_to_reg (argvec[i]);
2817 /* Store the values of the actuals into the formals. */
2819 for (f = formals, a = actuals, i = 0; f;
2820 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2822 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2823 emit_move_insn (DECL_RTL (f), argvec[i]);
2825 convert_move (DECL_RTL (f), argvec[i],
2826 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2833 /* Generate the RTL code for entering a binding contour.
2834 The variables are declared one by one, by calls to `expand_decl'.
2836 EXIT_FLAG is nonzero if this construct should be visible to
2837 `exit_something'. */
2840 expand_start_bindings (exit_flag)
2843 struct nesting *thisblock = ALLOC_NESTING ();
2844 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2846 /* Make an entry on block_stack for the block we are entering. */
2848 thisblock->next = block_stack;
2849 thisblock->all = nesting_stack;
2850 thisblock->depth = ++nesting_depth;
2851 thisblock->data.block.stack_level = 0;
2852 thisblock->data.block.cleanups = 0;
2853 thisblock->data.block.function_call_count = 0;
2857 if (block_stack->data.block.cleanups == NULL_TREE
2858 && (block_stack->data.block.outer_cleanups == NULL_TREE
2859 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2860 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2862 thisblock->data.block.outer_cleanups
2863 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2864 block_stack->data.block.outer_cleanups);
2867 thisblock->data.block.outer_cleanups = 0;
2871 && !(block_stack->data.block.cleanups == NULL_TREE
2872 && block_stack->data.block.outer_cleanups == NULL_TREE))
2873 thisblock->data.block.outer_cleanups
2874 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2875 block_stack->data.block.outer_cleanups);
2877 thisblock->data.block.outer_cleanups = 0;
2879 thisblock->data.block.label_chain = 0;
2880 thisblock->data.block.innermost_stack_block = stack_block_stack;
2881 thisblock->data.block.first_insn = note;
2882 thisblock->data.block.block_start_count = ++block_start_count;
2883 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2884 block_stack = thisblock;
2885 nesting_stack = thisblock;
2887 if (!output_bytecode)
2889 /* Make a new level for allocating stack slots. */
2894 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2895 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2899 remember_end_note (block)
2900 register tree block;
2902 BLOCK_END_NOTE (block) = last_block_end_note;
2903 last_block_end_note = NULL_RTX;
2906 /* Generate RTL code to terminate a binding contour.
2907 VARS is the chain of VAR_DECL nodes
2908 for the variables bound in this contour.
2909 MARK_ENDS is nonzero if we should put a note at the beginning
2910 and end of this binding contour.
2912 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2913 (That is true automatically if the contour has a saved stack level.) */
2916 expand_end_bindings (vars, mark_ends, dont_jump_in)
2921 register struct nesting *thisblock = block_stack;
2924 if (output_bytecode)
2926 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
2931 for (decl = vars; decl; decl = TREE_CHAIN (decl))
2932 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
2933 && ! DECL_IN_SYSTEM_HEADER (decl))
2934 warning_with_decl (decl, "unused variable `%s'");
2936 if (thisblock->exit_label)
2938 do_pending_stack_adjust ();
2939 emit_label (thisblock->exit_label);
2942 /* If necessary, make a handler for nonlocal gotos taking
2943 place in the function calls in this block. */
2944 if (function_call_count != thisblock->data.block.function_call_count
2946 /* Make handler for outermost block
2947 if there were any nonlocal gotos to this function. */
2948 && (thisblock->next == 0 ? current_function_has_nonlocal_label
2949 /* Make handler for inner block if it has something
2950 special to do when you jump out of it. */
2951 : (thisblock->data.block.cleanups != 0
2952 || thisblock->data.block.stack_level != 0)))
2955 rtx afterward = gen_label_rtx ();
2956 rtx handler_label = gen_label_rtx ();
2957 rtx save_receiver = gen_reg_rtx (Pmode);
2960 /* Don't let jump_optimize delete the handler. */
2961 LABEL_PRESERVE_P (handler_label) = 1;
2963 /* Record the handler address in the stack slot for that purpose,
2964 during this block, saving and restoring the outer value. */
2965 if (thisblock->next != 0)
2967 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
2970 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
2971 insns = get_insns ();
2973 emit_insns_before (insns, thisblock->data.block.first_insn);
2977 emit_move_insn (nonlocal_goto_handler_slot,
2978 gen_rtx (LABEL_REF, Pmode, handler_label));
2979 insns = get_insns ();
2981 emit_insns_before (insns, thisblock->data.block.first_insn);
2983 /* Jump around the handler; it runs only when specially invoked. */
2984 emit_jump (afterward);
2985 emit_label (handler_label);
2987 #ifdef HAVE_nonlocal_goto
2988 if (! HAVE_nonlocal_goto)
2990 /* First adjust our frame pointer to its actual value. It was
2991 previously set to the start of the virtual area corresponding to
2992 the stacked variables when we branched here and now needs to be
2993 adjusted to the actual hardware fp value.
2995 Assignments are to virtual registers are converted by
2996 instantiate_virtual_regs into the corresponding assignment
2997 to the underlying register (fp in this case) that makes
2998 the original assignment true.
2999 So the following insn will actually be
3000 decrementing fp by STARTING_FRAME_OFFSET. */
3001 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3003 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3004 if (fixed_regs[ARG_POINTER_REGNUM])
3006 #ifdef ELIMINABLE_REGS
3007 /* If the argument pointer can be eliminated in favor of the
3008 frame pointer, we don't need to restore it. We assume here
3009 that if such an elimination is present, it can always be used.
3010 This is the case on all known machines; if we don't make this
3011 assumption, we do unnecessary saving on many machines. */
3012 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3015 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3016 if (elim_regs[i].from == ARG_POINTER_REGNUM
3017 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3020 if (i == sizeof elim_regs / sizeof elim_regs [0])
3023 /* Now restore our arg pointer from the address at which it
3024 was saved in our stack frame.
3025 If there hasn't be space allocated for it yet, make
3027 if (arg_pointer_save_area == 0)
3028 arg_pointer_save_area
3029 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3030 emit_move_insn (virtual_incoming_args_rtx,
3031 /* We need a pseudo here, or else
3032 instantiate_virtual_regs_1 complains. */
3033 copy_to_reg (arg_pointer_save_area));
3038 /* The handler expects the desired label address in the static chain
3039 register. It tests the address and does an appropriate jump
3040 to whatever label is desired. */
3041 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3042 /* Skip any labels we shouldn't be able to jump to from here. */
3043 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3045 rtx not_this = gen_label_rtx ();
3046 rtx this = gen_label_rtx ();
3047 do_jump_if_equal (static_chain_rtx,
3048 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3050 emit_jump (not_this);
3052 expand_goto (TREE_VALUE (link));
3053 emit_label (not_this);
3055 /* If label is not recognized, abort. */
3056 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3058 emit_label (afterward);
3061 /* Don't allow jumping into a block that has cleanups or a stack level. */
3063 || thisblock->data.block.stack_level != 0
3064 || thisblock->data.block.cleanups != 0)
3066 struct label_chain *chain;
3068 /* Any labels in this block are no longer valid to go to.
3069 Mark them to cause an error message. */
3070 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3072 DECL_TOO_LATE (chain->label) = 1;
3073 /* If any goto without a fixup came to this label,
3074 that must be an error, because gotos without fixups
3075 come from outside all saved stack-levels and all cleanups. */
3076 if (TREE_ADDRESSABLE (chain->label))
3077 error_with_decl (chain->label,
3078 "label `%s' used before containing binding contour");
3082 /* Restore stack level in effect before the block
3083 (only if variable-size objects allocated). */
3084 /* Perform any cleanups associated with the block. */
3086 if (thisblock->data.block.stack_level != 0
3087 || thisblock->data.block.cleanups != 0)
3089 /* Only clean up here if this point can actually be reached. */
3090 if (GET_CODE (get_last_insn ()) != BARRIER)
3092 /* Don't let cleanups affect ({...}) constructs. */
3093 int old_expr_stmts_for_value = expr_stmts_for_value;
3094 rtx old_last_expr_value = last_expr_value;
3095 tree old_last_expr_type = last_expr_type;
3096 expr_stmts_for_value = 0;
3098 /* Do the cleanups. */
3099 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE);
3100 do_pending_stack_adjust ();
3102 expr_stmts_for_value = old_expr_stmts_for_value;
3103 last_expr_value = old_last_expr_value;
3104 last_expr_type = old_last_expr_type;
3106 /* Restore the stack level. */
3108 if (thisblock->data.block.stack_level != 0)
3110 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3111 thisblock->data.block.stack_level, NULL_RTX);
3112 if (nonlocal_goto_handler_slot != 0)
3113 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3118 /* Any gotos out of this block must also do these things.
3119 Also report any gotos with fixups that came to labels in this
3121 fixup_gotos (thisblock,
3122 thisblock->data.block.stack_level,
3123 thisblock->data.block.cleanups,
3124 thisblock->data.block.first_insn,
3128 /* Mark the beginning and end of the scope if requested.
3129 We do this now, after running cleanups on the variables
3130 just going out of scope, so they are in scope for their cleanups. */
3133 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3135 /* Get rid of the beginning-mark if we don't make an end-mark. */
3136 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3138 /* If doing stupid register allocation, make sure lives of all
3139 register variables declared here extend thru end of scope. */
3142 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3144 rtx rtl = DECL_RTL (decl);
3145 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3149 /* Restore block_stack level for containing block. */
3151 stack_block_stack = thisblock->data.block.innermost_stack_block;
3152 POPSTACK (block_stack);
3154 /* Pop the stack slot nesting and free any slots at this level. */
3159 /* End a binding contour.
3160 VARS is the chain of VAR_DECL nodes for the variables bound
3161 in this contour. MARK_ENDS is nonzer if we should put a note
3162 at the beginning and end of this binding contour.
3163 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3167 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3172 struct nesting *thisbind = nesting_stack;
3176 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3177 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3178 warning_with_decl (decl, "unused variable `%s'");
3180 if (thisbind->exit_label)
3181 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3183 /* Pop block/bindings off stack */
3184 POPSTACK (block_stack);
3187 /* Generate RTL for the automatic variable declaration DECL.
3188 (Other kinds of declarations are simply ignored if seen here.)
3189 CLEANUP is an expression to be executed at exit from this binding contour;
3190 for example, in C++, it might call the destructor for this variable.
3192 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3193 either before or after calling `expand_decl' but before compiling
3194 any subsequent expressions. This is because CLEANUP may be expanded
3195 more than once, on different branches of execution.
3196 For the same reason, CLEANUP may not contain a CALL_EXPR
3197 except as its topmost node--else `preexpand_calls' would get confused.
3199 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3200 that is not associated with any particular variable.
3202 There is no special support here for C++ constructors.
3203 They should be handled by the proper code in DECL_INITIAL. */
3209 struct nesting *thisblock = block_stack;
3212 if (output_bytecode)
3214 bc_expand_decl (decl, 0);
3218 type = TREE_TYPE (decl);
3220 /* Only automatic variables need any expansion done.
3221 Static and external variables, and external functions,
3222 will be handled by `assemble_variable' (called from finish_decl).
3223 TYPE_DECL and CONST_DECL require nothing.
3224 PARM_DECLs are handled in `assign_parms'. */
3226 if (TREE_CODE (decl) != VAR_DECL)
3228 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3231 /* Create the RTL representation for the variable. */
3233 if (type == error_mark_node)
3234 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3235 else if (DECL_SIZE (decl) == 0)
3236 /* Variable with incomplete type. */
3238 if (DECL_INITIAL (decl) == 0)
3239 /* Error message was already done; now avoid a crash. */
3240 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3242 /* An initializer is going to decide the size of this array.
3243 Until we know the size, represent its address with a reg. */
3244 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3246 else if (DECL_MODE (decl) != BLKmode
3247 /* If -ffloat-store, don't put explicit float vars
3249 && !(flag_float_store
3250 && TREE_CODE (type) == REAL_TYPE)
3251 && ! TREE_THIS_VOLATILE (decl)
3252 && ! TREE_ADDRESSABLE (decl)
3253 && (DECL_REGISTER (decl) || ! obey_regdecls))
3255 /* Automatic variable that can go in a register. */
3256 int unsignedp = TREE_UNSIGNED (type);
3257 enum machine_mode reg_mode
3258 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3260 if (TREE_CODE (type) == COMPLEX_TYPE)
3262 rtx realpart, imagpart;
3263 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3265 /* For a complex type variable, make a CONCAT of two pseudos
3266 so that the real and imaginary parts
3267 can be allocated separately. */
3268 realpart = gen_reg_rtx (partmode);
3269 REG_USERVAR_P (realpart) = 1;
3270 imagpart = gen_reg_rtx (partmode);
3271 REG_USERVAR_P (imagpart) = 1;
3272 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3276 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3277 if (TREE_CODE (type) == POINTER_TYPE)
3278 mark_reg_pointer (DECL_RTL (decl));
3279 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3282 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3284 /* Variable of fixed size that goes on the stack. */
3288 /* If we previously made RTL for this decl, it must be an array
3289 whose size was determined by the initializer.
3290 The old address was a register; set that register now
3291 to the proper address. */
3292 if (DECL_RTL (decl) != 0)
3294 if (GET_CODE (DECL_RTL (decl)) != MEM
3295 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3297 oldaddr = XEXP (DECL_RTL (decl), 0);
3301 = assign_stack_temp (DECL_MODE (decl),
3302 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3303 + BITS_PER_UNIT - 1)
3307 /* Set alignment we actually gave this decl. */
3308 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3309 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3313 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3314 if (addr != oldaddr)
3315 emit_move_insn (oldaddr, addr);
3318 /* If this is a memory ref that contains aggregate components,
3319 mark it as such for cse and loop optimize. */
3320 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3322 /* If this is in memory because of -ffloat-store,
3323 set the volatile bit, to prevent optimizations from
3324 undoing the effects. */
3325 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3326 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3330 /* Dynamic-size object: must push space on the stack. */
3334 /* Record the stack pointer on entry to block, if have
3335 not already done so. */
3336 if (thisblock->data.block.stack_level == 0)
3338 do_pending_stack_adjust ();
3339 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3340 &thisblock->data.block.stack_level,
3341 thisblock->data.block.first_insn);
3342 stack_block_stack = thisblock;
3345 /* Compute the variable's size, in bytes. */
3346 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3348 size_int (BITS_PER_UNIT)),
3349 NULL_RTX, VOIDmode, 0);
3352 /* Allocate space on the stack for the variable. */
3353 address = allocate_dynamic_stack_space (size, NULL_RTX,
3356 /* Reference the variable indirect through that rtx. */
3357 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3359 /* If this is a memory ref that contains aggregate components,
3360 mark it as such for cse and loop optimize. */
3361 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3363 /* Indicate the alignment we actually gave this variable. */
3364 #ifdef STACK_BOUNDARY
3365 DECL_ALIGN (decl) = STACK_BOUNDARY;
3367 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3371 if (TREE_THIS_VOLATILE (decl))
3372 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3373 #if 0 /* A variable is not necessarily unchanging
3374 just because it is const. RTX_UNCHANGING_P
3375 means no change in the function,
3376 not merely no change in the variable's scope.
3377 It is correct to set RTX_UNCHANGING_P if the variable's scope
3378 is the whole function. There's no convenient way to test that. */
3379 if (TREE_READONLY (decl))
3380 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3383 /* If doing stupid register allocation, make sure life of any
3384 register variable starts here, at the start of its scope. */
3387 use_variable (DECL_RTL (decl));
3391 /* Generate code for the automatic variable declaration DECL. For
3392 most variables this just means we give it a stack offset. The
3393 compiler sometimes emits cleanups without variables and we will
3394 have to deal with those too. */
3397 bc_expand_decl (decl, cleanup)
3405 /* A cleanup with no variable. */
3412 /* Only auto variables need any work. */
3413 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3416 type = TREE_TYPE (decl);
3418 if (type == error_mark_node)
3419 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3421 else if (DECL_SIZE (decl) == 0)
3423 /* Variable with incomplete type. The stack offset herein will be
3424 fixed later in expand_decl_init (). */
3425 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3427 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3429 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3433 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3436 /* Emit code to perform the initialization of a declaration DECL. */
3439 expand_decl_init (decl)
3442 int was_used = TREE_USED (decl);
3444 if (output_bytecode)
3446 bc_expand_decl_init (decl);
3450 /* If this is a CONST_DECL, we don't have to generate any code, but
3451 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3452 to be set while in the obstack containing the constant. If we don't
3453 do this, we can lose if we have functions nested three deep and the middle
3454 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3455 the innermost function is the first to expand that STRING_CST. */
3456 if (TREE_CODE (decl) == CONST_DECL)
3458 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3459 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3460 EXPAND_INITIALIZER);
3464 if (TREE_STATIC (decl))
3467 /* Compute and store the initial value now. */
3469 if (DECL_INITIAL (decl) == error_mark_node)
3471 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3472 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3473 || code == POINTER_TYPE)
3474 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3478 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3480 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3481 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3485 /* Don't let the initialization count as "using" the variable. */
3486 TREE_USED (decl) = was_used;
3488 /* Free any temporaries we made while initializing the decl. */
3492 /* Expand initialization for variable-sized types. Allocate array
3493 using newlocalSI and set local variable, which is a pointer to the
3497 bc_expand_variable_local_init (decl)
3500 /* Evaluate size expression and coerce to SI */
3501 bc_expand_expr (DECL_SIZE (decl));
3503 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3504 no coercion is necessary (?) */
3506 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3507 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3509 /* Emit code to allocate array */
3510 bc_emit_instruction (newlocalSI);
3512 /* Store array pointer in local variable. This is the only instance
3513 where we actually want the address of the pointer to the
3514 variable-size block, rather than the pointer itself. We avoid
3515 using expand_address() since that would cause the pointer to be
3516 pushed rather than its address. Hence the hard-coded reference;
3517 notice also that the variable is always local (no global
3518 variable-size type variables). */
3520 bc_load_localaddr (DECL_RTL (decl));
3521 bc_emit_instruction (storeP);
3525 /* Emit code to initialize a declaration. */
3528 bc_expand_decl_init (decl)
3531 int org_stack_depth;
3533 /* Statical initializers are handled elsewhere */
3535 if (TREE_STATIC (decl))
3538 /* Memory original stack depth */
3539 org_stack_depth = stack_depth;
3541 /* If the type is variable-size, we first create its space (we ASSUME
3542 it CAN'T be static). We do this regardless of whether there's an
3543 initializer assignment or not. */
3545 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3546 bc_expand_variable_local_init (decl);
3548 /* Expand initializer assignment */
3549 if (DECL_INITIAL (decl) == error_mark_node)
3551 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3553 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3554 || code == POINTER_TYPE)
3556 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3558 else if (DECL_INITIAL (decl))
3559 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3561 /* Restore stack depth */
3562 if (org_stack_depth > stack_depth)
3565 bc_adjust_stack (stack_depth - org_stack_depth);
3569 /* CLEANUP is an expression to be executed at exit from this binding contour;
3570 for example, in C++, it might call the destructor for this variable.
3572 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3573 either before or after calling `expand_decl' but before compiling
3574 any subsequent expressions. This is because CLEANUP may be expanded
3575 more than once, on different branches of execution.
3576 For the same reason, CLEANUP may not contain a CALL_EXPR
3577 except as its topmost node--else `preexpand_calls' would get confused.
3579 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3580 that is not associated with any particular variable. */
3583 expand_decl_cleanup (decl, cleanup)
3586 struct nesting *thisblock = block_stack;
3588 /* Error if we are not in any block. */
3592 /* Record the cleanup if there is one. */
3596 thisblock->data.block.cleanups
3597 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3598 /* If this block has a cleanup, it belongs in stack_block_stack. */
3599 stack_block_stack = thisblock;
3600 (*interim_eh_hook) (NULL_TREE);
3605 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3606 DECL_ELTS is the list of elements that belong to DECL's type.
3607 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3610 expand_anon_union_decl (decl, cleanup, decl_elts)
3611 tree decl, cleanup, decl_elts;
3613 struct nesting *thisblock = block_stack;
3616 expand_decl (decl, cleanup);
3617 x = DECL_RTL (decl);
3621 tree decl_elt = TREE_VALUE (decl_elts);
3622 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3623 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3625 /* Propagate the union's alignment to the elements. */
3626 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3628 /* If the element has BLKmode and the union doesn't, the union is
3629 aligned such that the element doesn't need to have BLKmode, so
3630 change the element's mode to the appropriate one for its size. */
3631 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3632 DECL_MODE (decl_elt) = mode
3633 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3636 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3637 instead create a new MEM rtx with the proper mode. */
3638 if (GET_CODE (x) == MEM)
3640 if (mode == GET_MODE (x))
3641 DECL_RTL (decl_elt) = x;
3644 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3645 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3646 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3649 else if (GET_CODE (x) == REG)
3651 if (mode == GET_MODE (x))
3652 DECL_RTL (decl_elt) = x;
3654 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3659 /* Record the cleanup if there is one. */
3662 thisblock->data.block.cleanups
3663 = temp_tree_cons (decl_elt, cleanup_elt,
3664 thisblock->data.block.cleanups);
3666 decl_elts = TREE_CHAIN (decl_elts);
3670 /* Expand a list of cleanups LIST.
3671 Elements may be expressions or may be nested lists.
3673 If DONT_DO is nonnull, then any list-element
3674 whose TREE_PURPOSE matches DONT_DO is omitted.
3675 This is sometimes used to avoid a cleanup associated with
3676 a value that is being returned out of the scope. */
3679 expand_cleanups (list, dont_do)
3684 for (tail = list; tail; tail = TREE_CHAIN (tail))
3685 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3687 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3688 expand_cleanups (TREE_VALUE (tail), dont_do);
3691 (*interim_eh_hook) (TREE_VALUE (tail));
3693 /* Cleanups may be run multiple times. For example,
3694 when exiting a binding contour, we expand the
3695 cleanups associated with that contour. When a goto
3696 within that binding contour has a target outside that
3697 contour, it will expand all cleanups from its scope to
3698 the target. Though the cleanups are expanded multiple
3699 times, the control paths are non-overlapping so the
3700 cleanups will not be executed twice. */
3701 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3707 /* Move all cleanups from the current block_stack
3708 to the containing block_stack, where they are assumed to
3709 have been created. If anything can cause a temporary to
3710 be created, but not expanded for more than one level of
3711 block_stacks, then this code will have to change. */
3716 struct nesting *block = block_stack;
3717 struct nesting *outer = block->next;
3719 outer->data.block.cleanups
3720 = chainon (block->data.block.cleanups,
3721 outer->data.block.cleanups);
3722 block->data.block.cleanups = 0;
3726 last_cleanup_this_contour ()
3728 if (block_stack == 0)
3731 return block_stack->data.block.cleanups;
3734 /* Return 1 if there are any pending cleanups at this point.
3735 If THIS_CONTOUR is nonzero, check the current contour as well.
3736 Otherwise, look only at the contours that enclose this one. */
3739 any_pending_cleanups (this_contour)
3742 struct nesting *block;
3744 if (block_stack == 0)
3747 if (this_contour && block_stack->data.block.cleanups != NULL)
3749 if (block_stack->data.block.cleanups == 0
3750 && (block_stack->data.block.outer_cleanups == 0
3752 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3757 for (block = block_stack->next; block; block = block->next)
3758 if (block->data.block.cleanups != 0)
3764 /* Enter a case (Pascal) or switch (C) statement.
3765 Push a block onto case_stack and nesting_stack
3766 to accumulate the case-labels that are seen
3767 and to record the labels generated for the statement.
3769 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3770 Otherwise, this construct is transparent for `exit_something'.
3772 EXPR is the index-expression to be dispatched on.
3773 TYPE is its nominal type. We could simply convert EXPR to this type,
3774 but instead we take short cuts. */
3777 expand_start_case (exit_flag, expr, type, printname)
3783 register struct nesting *thiscase = ALLOC_NESTING ();
3785 /* Make an entry on case_stack for the case we are entering. */
3787 thiscase->next = case_stack;
3788 thiscase->all = nesting_stack;
3789 thiscase->depth = ++nesting_depth;
3790 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3791 thiscase->data.case_stmt.case_list = 0;
3792 thiscase->data.case_stmt.index_expr = expr;
3793 thiscase->data.case_stmt.nominal_type = type;
3794 thiscase->data.case_stmt.default_label = 0;
3795 thiscase->data.case_stmt.num_ranges = 0;
3796 thiscase->data.case_stmt.printname = printname;
3797 thiscase->data.case_stmt.seenlabel = 0;
3798 case_stack = thiscase;
3799 nesting_stack = thiscase;
3801 if (output_bytecode)
3803 bc_expand_start_case (thiscase, expr, type, printname);
3807 do_pending_stack_adjust ();
3809 /* Make sure case_stmt.start points to something that won't
3810 need any transformation before expand_end_case. */
3811 if (GET_CODE (get_last_insn ()) != NOTE)
3812 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3814 thiscase->data.case_stmt.start = get_last_insn ();
3818 /* Enter a case statement. It is assumed that the caller has pushed
3819 the current context onto the case stack. */
3822 bc_expand_start_case (thiscase, expr, type, printname)
3823 struct nesting *thiscase;
3828 bc_expand_expr (expr);
3829 bc_expand_conversion (TREE_TYPE (expr), type);
3831 /* For cases, the skip is a place we jump to that's emitted after
3832 the size of the jump table is known. */
3834 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3835 bc_emit_bytecode (jump);
3836 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3838 #ifdef DEBUG_PRINT_CODE
3839 fputc ('\n', stderr);
3844 /* Start a "dummy case statement" within which case labels are invalid
3845 and are not connected to any larger real case statement.
3846 This can be used if you don't want to let a case statement jump
3847 into the middle of certain kinds of constructs. */
3850 expand_start_case_dummy ()
3852 register struct nesting *thiscase = ALLOC_NESTING ();
3854 /* Make an entry on case_stack for the dummy. */
3856 thiscase->next = case_stack;
3857 thiscase->all = nesting_stack;
3858 thiscase->depth = ++nesting_depth;
3859 thiscase->exit_label = 0;
3860 thiscase->data.case_stmt.case_list = 0;
3861 thiscase->data.case_stmt.start = 0;
3862 thiscase->data.case_stmt.nominal_type = 0;
3863 thiscase->data.case_stmt.default_label = 0;
3864 thiscase->data.case_stmt.num_ranges = 0;
3865 case_stack = thiscase;
3866 nesting_stack = thiscase;
3869 /* End a dummy case statement. */
3872 expand_end_case_dummy ()
3874 POPSTACK (case_stack);
3877 /* Return the data type of the index-expression
3878 of the innermost case statement, or null if none. */
3881 case_index_expr_type ()
3884 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3888 /* Accumulate one case or default label inside a case or switch statement.
3889 VALUE is the value of the case (a null pointer, for a default label).
3890 The function CONVERTER, when applied to arguments T and V,
3891 converts the value V to the type T.
3893 If not currently inside a case or switch statement, return 1 and do
3894 nothing. The caller will print a language-specific error message.
3895 If VALUE is a duplicate or overlaps, return 2 and do nothing
3896 except store the (first) duplicate node in *DUPLICATE.
3897 If VALUE is out of range, return 3 and do nothing.
3898 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3899 Return 0 on success.
3901 Extended to handle range statements. */
3904 pushcase (value, converter, label, duplicate)
3905 register tree value;
3906 tree (*converter) PROTO((tree, tree));
3907 register tree label;
3910 register struct case_node **l;
3911 register struct case_node *n;
3915 if (output_bytecode)
3916 return bc_pushcase (value, label);
3918 /* Fail if not inside a real case statement. */
3919 if (! (case_stack && case_stack->data.case_stmt.start))
3922 if (stack_block_stack
3923 && stack_block_stack->depth > case_stack->depth)
3926 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
3927 nominal_type = case_stack->data.case_stmt.nominal_type;
3929 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3930 if (index_type == error_mark_node)
3933 /* Convert VALUE to the type in which the comparisons are nominally done. */
3935 value = (*converter) (nominal_type, value);
3937 /* If this is the first label, warn if any insns have been emitted. */
3938 if (case_stack->data.case_stmt.seenlabel == 0)
3941 for (insn = case_stack->data.case_stmt.start;
3943 insn = NEXT_INSN (insn))
3945 if (GET_CODE (insn) == CODE_LABEL)
3947 if (GET_CODE (insn) != NOTE
3948 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
3950 warning ("unreachable code at beginning of %s",
3951 case_stack->data.case_stmt.printname);
3956 case_stack->data.case_stmt.seenlabel = 1;
3958 /* Fail if this value is out of range for the actual type of the index
3959 (which may be narrower than NOMINAL_TYPE). */
3960 if (value != 0 && ! int_fits_type_p (value, index_type))
3963 /* Fail if this is a duplicate or overlaps another entry. */
3966 if (case_stack->data.case_stmt.default_label != 0)
3968 *duplicate = case_stack->data.case_stmt.default_label;
3971 case_stack->data.case_stmt.default_label = label;
3975 /* Find the elt in the chain before which to insert the new value,
3976 to keep the chain sorted in increasing order.
3977 But report an error if this element is a duplicate. */
3978 for (l = &case_stack->data.case_stmt.case_list;
3979 /* Keep going past elements distinctly less than VALUE. */
3980 *l != 0 && tree_int_cst_lt ((*l)->high, value);
3985 /* Element we will insert before must be distinctly greater;
3986 overlap means error. */
3987 if (! tree_int_cst_lt (value, (*l)->low))
3989 *duplicate = (*l)->code_label;
3994 /* Add this label to the chain, and succeed.
3995 Copy VALUE so it is on temporary rather than momentary
3996 obstack and will thus survive till the end of the case statement. */
3997 n = (struct case_node *) oballoc (sizeof (struct case_node));
4000 n->high = n->low = copy_node (value);
4001 n->code_label = label;
4005 expand_label (label);
4009 /* Like pushcase but this case applies to all values
4010 between VALUE1 and VALUE2 (inclusive).
4011 The return value is the same as that of pushcase
4012 but there is one additional error code:
4013 4 means the specified range was empty. */
4016 pushcase_range (value1, value2, converter, label, duplicate)
4017 register tree value1, value2;
4018 tree (*converter) PROTO((tree, tree));
4019 register tree label;
4022 register struct case_node **l;
4023 register struct case_node *n;
4027 /* Fail if not inside a real case statement. */
4028 if (! (case_stack && case_stack->data.case_stmt.start))
4031 if (stack_block_stack
4032 && stack_block_stack->depth > case_stack->depth)
4035 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4036 nominal_type = case_stack->data.case_stmt.nominal_type;
4038 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4039 if (index_type == error_mark_node)
4042 /* If this is the first label, warn if any insns have been emitted. */
4043 if (case_stack->data.case_stmt.seenlabel == 0)
4046 for (insn = case_stack->data.case_stmt.start;
4048 insn = NEXT_INSN (insn))
4050 if (GET_CODE (insn) == CODE_LABEL)
4052 if (GET_CODE (insn) != NOTE
4053 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4055 warning ("unreachable code at beginning of %s",
4056 case_stack->data.case_stmt.printname);
4061 case_stack->data.case_stmt.seenlabel = 1;
4063 /* Convert VALUEs to type in which the comparisons are nominally done. */
4064 if (value1 == 0) /* Negative infinity. */
4065 value1 = TYPE_MIN_VALUE(index_type);
4066 value1 = (*converter) (nominal_type, value1);
4068 if (value2 == 0) /* Positive infinity. */
4069 value2 = TYPE_MAX_VALUE(index_type);
4070 value2 = (*converter) (nominal_type, value2);
4072 /* Fail if these values are out of range. */
4073 if (! int_fits_type_p (value1, index_type))
4076 if (! int_fits_type_p (value2, index_type))
4079 /* Fail if the range is empty. */
4080 if (tree_int_cst_lt (value2, value1))
4083 /* If the bounds are equal, turn this into the one-value case. */
4084 if (tree_int_cst_equal (value1, value2))
4085 return pushcase (value1, converter, label, duplicate);
4087 /* Find the elt in the chain before which to insert the new value,
4088 to keep the chain sorted in increasing order.
4089 But report an error if this element is a duplicate. */
4090 for (l = &case_stack->data.case_stmt.case_list;
4091 /* Keep going past elements distinctly less than this range. */
4092 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4097 /* Element we will insert before must be distinctly greater;
4098 overlap means error. */
4099 if (! tree_int_cst_lt (value2, (*l)->low))
4101 *duplicate = (*l)->code_label;
4106 /* Add this label to the chain, and succeed.
4107 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4108 obstack and will thus survive till the end of the case statement. */
4110 n = (struct case_node *) oballoc (sizeof (struct case_node));
4113 n->low = copy_node (value1);
4114 n->high = copy_node (value2);
4115 n->code_label = label;
4118 expand_label (label);
4120 case_stack->data.case_stmt.num_ranges++;
4126 /* Accumulate one case or default label; VALUE is the value of the
4127 case, or nil for a default label. If not currently inside a case,
4128 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4129 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4130 Return 0 on success. This function is a leftover from the earlier
4131 bytecode compiler, which was based on gcc 1.37. It should be
4132 merged into pushcase. */
4135 bc_pushcase (value, label)
4139 struct nesting *thiscase = case_stack;
4140 struct case_node *case_label, *new_label;
4145 /* Fail if duplicate, overlap, or out of type range. */
4148 value = convert (thiscase->data.case_stmt.nominal_type, value);
4149 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4152 for (case_label = thiscase->data.case_stmt.case_list;
4153 case_label->left; case_label = case_label->left)
4154 if (! tree_int_cst_lt (case_label->left->high, value))
4157 if (case_label != thiscase->data.case_stmt.case_list
4158 && ! tree_int_cst_lt (case_label->high, value)
4159 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4162 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4163 new_label->low = new_label->high = copy_node (value);
4164 new_label->code_label = label;
4165 new_label->left = case_label->left;
4167 case_label->left = new_label;
4168 thiscase->data.case_stmt.num_ranges++;
4172 if (thiscase->data.case_stmt.default_label)
4174 thiscase->data.case_stmt.default_label = label;
4177 expand_label (label);
4181 /* Returns the number of possible values of TYPE.
4182 Returns -1 if the number is unknown or variable.
4183 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4184 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4185 do not increase monotonically (there may be duplicates);
4186 to 1 if the values increase monotonically, but not always by 1;
4187 otherwise sets it to 0. */
4190 all_cases_count (type, spareness)
4194 HOST_WIDE_INT count, count_high = 0;
4197 switch (TREE_CODE (type))
4204 count = 1 << BITS_PER_UNIT;
4208 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4209 || TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST)
4214 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4215 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4216 but with overflow checking. */
4217 tree mint = TYPE_MIN_VALUE (type);
4218 tree maxt = TYPE_MAX_VALUE (type);
4219 HOST_WIDE_INT lo, hi;
4220 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4222 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4224 add_double (lo, hi, 1, 0, &lo, &hi);
4225 if (hi != 0 || lo < 0)
4232 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4234 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4235 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4236 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4237 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4241 if (*spareness == 1)
4243 tree prev = TREE_VALUE (TYPE_VALUES (type));
4244 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4246 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4251 prev = TREE_VALUE (t);
4260 #define BITARRAY_TEST(ARRAY, INDEX) \
4261 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4262 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4263 #define BITARRAY_SET(ARRAY, INDEX) \
4264 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4265 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4267 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4268 with the case values we have seen, assuming the case expression
4270 SPARSENESS is as determined by all_cases_count.
4272 The time needed is propotional to COUNT, unless
4273 SPARSENESS is 2, in which case quadratic time is needed. */
4276 mark_seen_cases (type, cases_seen, count, sparseness)
4278 unsigned char *cases_seen;
4284 tree next_node_to_try = NULL_TREE;
4285 long next_node_offset = 0;
4287 register struct case_node *n;
4288 tree val = make_node (INTEGER_CST);
4289 TREE_TYPE (val) = type;
4290 for (n = case_stack->data.case_stmt.case_list; n;
4293 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4294 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4295 while ( ! tree_int_cst_lt (n->high, val))
4297 /* Calculate (into xlo) the "offset" of the integer (val).
4298 The element with lowest value has offset 0, the next smallest
4299 element has offset 1, etc. */
4301 HOST_WIDE_INT xlo, xhi;
4303 if (sparseness == 2)
4305 /* This less efficient loop is only needed to handle
4306 duplicate case values (multiple enum constants
4307 with the same value). */
4308 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4309 t = TREE_CHAIN (t), xlo++)
4311 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4312 BITARRAY_SET (cases_seen, xlo);
4317 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4319 /* The TYPE_VALUES will be in increasing order, so
4320 starting searching where we last ended. */
4321 t = next_node_to_try;
4322 xlo = next_node_offset;
4328 t = TYPE_VALUES (type);
4331 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4333 next_node_to_try = TREE_CHAIN (t);
4334 next_node_offset = xlo + 1;
4339 if (t == next_node_to_try)
4345 t = TYPE_MIN_VALUE (type);
4347 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4351 add_double (xlo, xhi,
4352 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4356 if (xhi == 0 && xlo >= 0 && xlo < count)
4357 BITARRAY_SET (cases_seen, xlo);
4359 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4361 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4366 /* Called when the index of a switch statement is an enumerated type
4367 and there is no default label.
4369 Checks that all enumeration literals are covered by the case
4370 expressions of a switch. Also, warn if there are any extra
4371 switch cases that are *not* elements of the enumerated type.
4373 If all enumeration literals were covered by the case expressions,
4374 turn one of the expressions into the default expression since it should
4375 not be possible to fall through such a switch. */
4378 check_for_full_enumeration_handling (type)
4381 register struct case_node *n;
4382 register struct case_node **l;
4383 register tree chain;
4386 /* True iff the selector type is a numbered set mode. */
4389 /* The number of possible selector values. */
4392 /* For each possible selector value. a one iff it has been matched
4393 by a case value alternative. */
4394 unsigned char *cases_seen;
4396 /* The allocated size of cases_seen, in chars. */
4400 if (output_bytecode)
4402 bc_check_for_full_enumeration_handling (type);
4409 size = all_cases_count (type, &sparseness);
4410 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4412 if (size > 0 && size < 600000
4413 /* We deliberately use malloc here - not xmalloc. */
4414 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4417 tree v = TYPE_VALUES (type);
4418 bzero (cases_seen, bytes_needed);
4420 /* The time complexity of this code is normally O(N), where
4421 N being the number of members in the enumerated type.
4422 However, if type is a ENUMERAL_TYPE whose values do not
4423 increase monotonically, quadratic time may be needed. */
4425 mark_seen_cases (type, cases_seen, size, sparseness);
4427 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4429 if (BITARRAY_TEST(cases_seen, i) == 0)
4430 warning ("enumeration value `%s' not handled in switch",
4431 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4437 /* Now we go the other way around; we warn if there are case
4438 expressions that don't correspond to enumerators. This can
4439 occur since C and C++ don't enforce type-checking of
4440 assignments to enumeration variables. */
4443 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4445 for (chain = TYPE_VALUES (type);
4446 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4447 chain = TREE_CHAIN (chain))
4452 if (TYPE_NAME (type) == 0)
4453 warning ("case value `%d' not in enumerated type",
4454 TREE_INT_CST_LOW (n->low));
4456 warning ("case value `%d' not in enumerated type `%s'",
4457 TREE_INT_CST_LOW (n->low),
4458 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4461 : DECL_NAME (TYPE_NAME (type))));
4463 if (!tree_int_cst_equal (n->low, n->high))
4465 for (chain = TYPE_VALUES (type);
4466 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4467 chain = TREE_CHAIN (chain))
4472 if (TYPE_NAME (type) == 0)
4473 warning ("case value `%d' not in enumerated type",
4474 TREE_INT_CST_LOW (n->high));
4476 warning ("case value `%d' not in enumerated type `%s'",
4477 TREE_INT_CST_LOW (n->high),
4478 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4481 : DECL_NAME (TYPE_NAME (type))));
4487 /* ??? This optimization is disabled because it causes valid programs to
4488 fail. ANSI C does not guarantee that an expression with enum type
4489 will have a value that is the same as one of the enumation literals. */
4491 /* If all values were found as case labels, make one of them the default
4492 label. Thus, this switch will never fall through. We arbitrarily pick
4493 the last one to make the default since this is likely the most
4494 efficient choice. */
4498 for (l = &case_stack->data.case_stmt.case_list;
4503 case_stack->data.case_stmt.default_label = (*l)->code_label;
4510 /* Check that all enumeration literals are covered by the case
4511 expressions of a switch. Also warn if there are any cases
4512 that are not elements of the enumerated type. */
4515 bc_check_for_full_enumeration_handling (type)
4518 struct nesting *thiscase = case_stack;
4519 struct case_node *c;
4522 /* Check for enums not handled. */
4523 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4525 for (c = thiscase->data.case_stmt.case_list->left;
4526 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4529 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4530 warning ("enumerated value `%s' not handled in switch",
4531 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4534 /* Check for cases not in the enumeration. */
4535 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4537 for (e = TYPE_VALUES (type);
4538 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4542 warning ("case value `%d' not in enumerated type `%s'",
4543 TREE_INT_CST_LOW (c->low),
4544 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4546 : DECL_NAME (TYPE_NAME (type))));
4550 /* Terminate a case (Pascal) or switch (C) statement
4551 in which ORIG_INDEX is the expression to be tested.
4552 Generate the code to test it and jump to the right place. */
4555 expand_end_case (orig_index)
4558 tree minval, maxval, range, orig_minval;
4559 rtx default_label = 0;
4560 register struct case_node *n;
4568 register struct nesting *thiscase = case_stack;
4569 tree index_expr, index_type;
4572 if (output_bytecode)
4574 bc_expand_end_case (orig_index);
4578 table_label = gen_label_rtx ();
4579 index_expr = thiscase->data.case_stmt.index_expr;
4580 index_type = TREE_TYPE (index_expr);
4581 unsignedp = TREE_UNSIGNED (index_type);
4583 do_pending_stack_adjust ();
4585 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4586 if (index_type != error_mark_node)
4588 /* If switch expression was an enumerated type, check that all
4589 enumeration literals are covered by the cases.
4590 No sense trying this if there's a default case, however. */
4592 if (!thiscase->data.case_stmt.default_label
4593 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4594 && TREE_CODE (index_expr) != INTEGER_CST)
4595 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4597 /* If this is the first label, warn if any insns have been emitted. */
4598 if (thiscase->data.case_stmt.seenlabel == 0)
4601 for (insn = get_last_insn ();
4602 insn != case_stack->data.case_stmt.start;
4603 insn = PREV_INSN (insn))
4604 if (GET_CODE (insn) != NOTE
4605 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4607 warning ("unreachable code at beginning of %s",
4608 case_stack->data.case_stmt.printname);
4613 /* If we don't have a default-label, create one here,
4614 after the body of the switch. */
4615 if (thiscase->data.case_stmt.default_label == 0)
4617 thiscase->data.case_stmt.default_label
4618 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4619 expand_label (thiscase->data.case_stmt.default_label);
4621 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4623 before_case = get_last_insn ();
4625 /* Simplify the case-list before we count it. */
4626 group_case_nodes (thiscase->data.case_stmt.case_list);
4628 /* Get upper and lower bounds of case values.
4629 Also convert all the case values to the index expr's data type. */
4632 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4634 /* Check low and high label values are integers. */
4635 if (TREE_CODE (n->low) != INTEGER_CST)
4637 if (TREE_CODE (n->high) != INTEGER_CST)
4640 n->low = convert (index_type, n->low);
4641 n->high = convert (index_type, n->high);
4643 /* Count the elements and track the largest and smallest
4644 of them (treating them as signed even if they are not). */
4652 if (INT_CST_LT (n->low, minval))
4654 if (INT_CST_LT (maxval, n->high))
4657 /* A range counts double, since it requires two compares. */
4658 if (! tree_int_cst_equal (n->low, n->high))
4662 orig_minval = minval;
4664 /* Compute span of values. */
4666 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4670 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4672 emit_jump (default_label);
4675 /* If range of values is much bigger than number of values,
4676 make a sequence of conditional branches instead of a dispatch.
4677 If the switch-index is a constant, do it this way
4678 because we can optimize it. */
4680 #ifndef CASE_VALUES_THRESHOLD
4682 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4684 /* If machine does not have a case insn that compares the
4685 bounds, this means extra overhead for dispatch tables
4686 which raises the threshold for using them. */
4687 #define CASE_VALUES_THRESHOLD 5
4688 #endif /* HAVE_casesi */
4689 #endif /* CASE_VALUES_THRESHOLD */
4691 else if (TREE_INT_CST_HIGH (range) != 0
4692 || count < CASE_VALUES_THRESHOLD
4693 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4695 || TREE_CODE (index_expr) == INTEGER_CST
4696 /* These will reduce to a constant. */
4697 || (TREE_CODE (index_expr) == CALL_EXPR
4698 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4699 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4700 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4701 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4702 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4704 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4706 /* If the index is a short or char that we do not have
4707 an insn to handle comparisons directly, convert it to
4708 a full integer now, rather than letting each comparison
4709 generate the conversion. */
4711 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4712 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4713 == CODE_FOR_nothing))
4715 enum machine_mode wider_mode;
4716 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4717 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4718 if (cmp_optab->handlers[(int) wider_mode].insn_code
4719 != CODE_FOR_nothing)
4721 index = convert_to_mode (wider_mode, index, unsignedp);
4727 do_pending_stack_adjust ();
4729 index = protect_from_queue (index, 0);
4730 if (GET_CODE (index) == MEM)
4731 index = copy_to_reg (index);
4732 if (GET_CODE (index) == CONST_INT
4733 || TREE_CODE (index_expr) == INTEGER_CST)
4735 /* Make a tree node with the proper constant value
4736 if we don't already have one. */
4737 if (TREE_CODE (index_expr) != INTEGER_CST)
4740 = build_int_2 (INTVAL (index),
4741 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4742 index_expr = convert (index_type, index_expr);
4745 /* For constant index expressions we need only
4746 issue a unconditional branch to the appropriate
4747 target code. The job of removing any unreachable
4748 code is left to the optimisation phase if the
4749 "-O" option is specified. */
4750 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4751 if (! tree_int_cst_lt (index_expr, n->low)
4752 && ! tree_int_cst_lt (n->high, index_expr))
4756 emit_jump (label_rtx (n->code_label));
4758 emit_jump (default_label);
4762 /* If the index expression is not constant we generate
4763 a binary decision tree to select the appropriate
4764 target code. This is done as follows:
4766 The list of cases is rearranged into a binary tree,
4767 nearly optimal assuming equal probability for each case.
4769 The tree is transformed into RTL, eliminating
4770 redundant test conditions at the same time.
4772 If program flow could reach the end of the
4773 decision tree an unconditional jump to the
4774 default code is emitted. */
4777 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4778 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4779 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4781 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4782 default_label, index_type);
4783 emit_jump_if_reachable (default_label);
4792 enum machine_mode index_mode = SImode;
4793 int index_bits = GET_MODE_BITSIZE (index_mode);
4795 enum machine_mode op_mode;
4797 /* Convert the index to SImode. */
4798 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4799 > GET_MODE_BITSIZE (index_mode))
4801 enum machine_mode omode = TYPE_MODE (index_type);
4802 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4804 /* We must handle the endpoints in the original mode. */
4805 index_expr = build (MINUS_EXPR, index_type,
4806 index_expr, minval);
4807 minval = integer_zero_node;
4808 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4809 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4810 emit_jump_insn (gen_bltu (default_label));
4811 /* Now we can safely truncate. */
4812 index = convert_to_mode (index_mode, index, 0);
4816 if (TYPE_MODE (index_type) != index_mode)
4818 index_expr = convert (type_for_size (index_bits, 0),
4820 index_type = TREE_TYPE (index_expr);
4823 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4826 index = protect_from_queue (index, 0);
4827 do_pending_stack_adjust ();
4829 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4830 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4832 index = copy_to_mode_reg (op_mode, index);
4834 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4836 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4837 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4839 op1 = copy_to_mode_reg (op_mode, op1);
4841 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4843 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4844 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4846 op2 = copy_to_mode_reg (op_mode, op2);
4848 emit_jump_insn (gen_casesi (index, op1, op2,
4849 table_label, default_label));
4853 #ifdef HAVE_tablejump
4854 if (! win && HAVE_tablejump)
4856 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4857 fold (build (MINUS_EXPR, index_type,
4858 index_expr, minval)));
4859 index_type = TREE_TYPE (index_expr);
4860 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4862 index = protect_from_queue (index, 0);
4863 do_pending_stack_adjust ();
4865 do_tablejump (index, TYPE_MODE (index_type),
4866 expand_expr (range, NULL_RTX, VOIDmode, 0),
4867 table_label, default_label);
4874 /* Get table of labels to jump to, in order of case index. */
4876 ncases = TREE_INT_CST_LOW (range) + 1;
4877 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4878 bzero ((char *) labelvec, ncases * sizeof (rtx));
4880 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4882 register HOST_WIDE_INT i
4883 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4888 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4889 if (i + TREE_INT_CST_LOW (orig_minval)
4890 == TREE_INT_CST_LOW (n->high))
4896 /* Fill in the gaps with the default. */
4897 for (i = 0; i < ncases; i++)
4898 if (labelvec[i] == 0)
4899 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4901 /* Output the table */
4902 emit_label (table_label);
4904 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
4905 were an expression, instead of an #ifdef/#ifndef. */
4907 #ifdef CASE_VECTOR_PC_RELATIVE
4911 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
4912 gen_rtx (LABEL_REF, Pmode, table_label),
4913 gen_rtvec_v (ncases, labelvec)));
4915 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
4916 gen_rtvec_v (ncases, labelvec)));
4918 /* If the case insn drops through the table,
4919 after the table we must jump to the default-label.
4920 Otherwise record no drop-through after the table. */
4921 #ifdef CASE_DROPS_THROUGH
4922 emit_jump (default_label);
4928 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
4929 reorder_insns (before_case, get_last_insn (),
4930 thiscase->data.case_stmt.start);
4933 if (thiscase->exit_label)
4934 emit_label (thiscase->exit_label);
4936 POPSTACK (case_stack);
4942 /* Terminate a case statement. EXPR is the original index
4946 bc_expand_end_case (expr)
4949 struct nesting *thiscase = case_stack;
4950 enum bytecode_opcode opcode;
4951 struct bc_label *jump_label;
4952 struct case_node *c;
4954 bc_emit_bytecode (jump);
4955 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
4957 #ifdef DEBUG_PRINT_CODE
4958 fputc ('\n', stderr);
4961 /* Now that the size of the jump table is known, emit the actual
4962 indexed jump instruction. */
4963 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
4965 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
4966 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
4967 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
4969 bc_emit_bytecode (opcode);
4971 /* Now emit the case instructions literal arguments, in order.
4972 In addition to the value on the stack, it uses:
4973 1. The address of the jump table.
4974 2. The size of the jump table.
4975 3. The default label. */
4977 jump_label = bc_get_bytecode_label ();
4978 bc_emit_bytecode_labelref (jump_label);
4979 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
4980 sizeof thiscase->data.case_stmt.num_ranges);
4982 if (thiscase->data.case_stmt.default_label)
4983 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
4985 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
4987 /* Output the jump table. */
4989 bc_align_bytecode (3 /* PTR_ALIGN */);
4990 bc_emit_bytecode_labeldef (jump_label);
4992 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
4993 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4995 opcode = TREE_INT_CST_LOW (c->low);
4996 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
4998 opcode = TREE_INT_CST_LOW (c->high);
4999 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5001 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5004 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5005 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5007 bc_emit_bytecode_DI_const (c->low);
5008 bc_emit_bytecode_DI_const (c->high);
5010 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5017 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5019 /* Possibly issue enumeration warnings. */
5021 if (!thiscase->data.case_stmt.default_label
5022 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5023 && TREE_CODE (expr) != INTEGER_CST
5025 check_for_full_enumeration_handling (TREE_TYPE (expr));
5028 #ifdef DEBUG_PRINT_CODE
5029 fputc ('\n', stderr);
5032 POPSTACK (case_stack);
5036 /* Return unique bytecode ID. */
5041 static int bc_uid = 0;
5046 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5049 do_jump_if_equal (op1, op2, label, unsignedp)
5050 rtx op1, op2, label;
5053 if (GET_CODE (op1) == CONST_INT
5054 && GET_CODE (op2) == CONST_INT)
5056 if (INTVAL (op1) == INTVAL (op2))
5061 enum machine_mode mode = GET_MODE (op1);
5062 if (mode == VOIDmode)
5063 mode = GET_MODE (op2);
5064 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5065 emit_jump_insn (gen_beq (label));
5069 /* Not all case values are encountered equally. This function
5070 uses a heuristic to weight case labels, in cases where that
5071 looks like a reasonable thing to do.
5073 Right now, all we try to guess is text, and we establish the
5076 chars above space: 16
5085 If we find any cases in the switch that are not either -1 or in the range
5086 of valid ASCII characters, or are control characters other than those
5087 commonly used with "\", don't treat this switch scanning text.
5089 Return 1 if these nodes are suitable for cost estimation, otherwise
5093 estimate_case_costs (node)
5096 tree min_ascii = build_int_2 (-1, -1);
5097 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5101 /* If we haven't already made the cost table, make it now. Note that the
5102 lower bound of the table is -1, not zero. */
5104 if (cost_table == NULL)
5106 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5107 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5109 for (i = 0; i < 128; i++)
5113 else if (ispunct (i))
5115 else if (iscntrl (i))
5119 cost_table[' '] = 8;
5120 cost_table['\t'] = 4;
5121 cost_table['\0'] = 4;
5122 cost_table['\n'] = 2;
5123 cost_table['\f'] = 1;
5124 cost_table['\v'] = 1;
5125 cost_table['\b'] = 1;
5128 /* See if all the case expressions look like text. It is text if the
5129 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5130 as signed arithmetic since we don't want to ever access cost_table with a
5131 value less than -1. Also check that none of the constants in a range
5132 are strange control characters. */
5134 for (n = node; n; n = n->right)
5136 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5139 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5140 if (cost_table[i] < 0)
5144 /* All interesting values are within the range of interesting
5145 ASCII characters. */
5149 /* Scan an ordered list of case nodes
5150 combining those with consecutive values or ranges.
5152 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5155 group_case_nodes (head)
5158 case_node_ptr node = head;
5162 rtx lb = next_real_insn (label_rtx (node->code_label));
5163 case_node_ptr np = node;
5165 /* Try to group the successors of NODE with NODE. */
5166 while (((np = np->right) != 0)
5167 /* Do they jump to the same place? */
5168 && next_real_insn (label_rtx (np->code_label)) == lb
5169 /* Are their ranges consecutive? */
5170 && tree_int_cst_equal (np->low,
5171 fold (build (PLUS_EXPR,
5172 TREE_TYPE (node->high),
5175 /* An overflow is not consecutive. */
5176 && tree_int_cst_lt (node->high,
5177 fold (build (PLUS_EXPR,
5178 TREE_TYPE (node->high),
5180 integer_one_node))))
5182 node->high = np->high;
5184 /* NP is the first node after NODE which can't be grouped with it.
5185 Delete the nodes in between, and move on to that node. */
5191 /* Take an ordered list of case nodes
5192 and transform them into a near optimal binary tree,
5193 on the assumption that any target code selection value is as
5194 likely as any other.
5196 The transformation is performed by splitting the ordered
5197 list into two equal sections plus a pivot. The parts are
5198 then attached to the pivot as left and right branches. Each
5199 branch is is then transformed recursively. */
5202 balance_case_nodes (head, parent)
5203 case_node_ptr *head;
5204 case_node_ptr parent;
5206 register case_node_ptr np;
5214 register case_node_ptr *npp;
5217 /* Count the number of entries on branch. Also count the ranges. */
5221 if (!tree_int_cst_equal (np->low, np->high))
5225 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5229 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5237 /* Split this list if it is long enough for that to help. */
5242 /* Find the place in the list that bisects the list's total cost,
5243 Here I gets half the total cost. */
5248 /* Skip nodes while their cost does not reach that amount. */
5249 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5250 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5251 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5254 npp = &(*npp)->right;
5259 /* Leave this branch lopsided, but optimize left-hand
5260 side and fill in `parent' fields for right-hand side. */
5262 np->parent = parent;
5263 balance_case_nodes (&np->left, np);
5264 for (; np->right; np = np->right)
5265 np->right->parent = np;
5269 /* If there are just three nodes, split at the middle one. */
5271 npp = &(*npp)->right;
5274 /* Find the place in the list that bisects the list's total cost,
5275 where ranges count as 2.
5276 Here I gets half the total cost. */
5277 i = (i + ranges + 1) / 2;
5280 /* Skip nodes while their cost does not reach that amount. */
5281 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5286 npp = &(*npp)->right;
5291 np->parent = parent;
5294 /* Optimize each of the two split parts. */
5295 balance_case_nodes (&np->left, np);
5296 balance_case_nodes (&np->right, np);
5300 /* Else leave this branch as one level,
5301 but fill in `parent' fields. */
5303 np->parent = parent;
5304 for (; np->right; np = np->right)
5305 np->right->parent = np;
5310 /* Search the parent sections of the case node tree
5311 to see if a test for the lower bound of NODE would be redundant.
5312 INDEX_TYPE is the type of the index expression.
5314 The instructions to generate the case decision tree are
5315 output in the same order as nodes are processed so it is
5316 known that if a parent node checks the range of the current
5317 node minus one that the current node is bounded at its lower
5318 span. Thus the test would be redundant. */
5321 node_has_low_bound (node, index_type)
5326 case_node_ptr pnode;
5328 /* If the lower bound of this node is the lowest value in the index type,
5329 we need not test it. */
5331 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5334 /* If this node has a left branch, the value at the left must be less
5335 than that at this node, so it cannot be bounded at the bottom and
5336 we need not bother testing any further. */
5341 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5342 node->low, integer_one_node));
5344 /* If the subtraction above overflowed, we can't verify anything.
5345 Otherwise, look for a parent that tests our value - 1. */
5347 if (! tree_int_cst_lt (low_minus_one, node->low))
5350 for (pnode = node->parent; pnode; pnode = pnode->parent)
5351 if (tree_int_cst_equal (low_minus_one, pnode->high))
5357 /* Search the parent sections of the case node tree
5358 to see if a test for the upper bound of NODE would be redundant.
5359 INDEX_TYPE is the type of the index expression.
5361 The instructions to generate the case decision tree are
5362 output in the same order as nodes are processed so it is
5363 known that if a parent node checks the range of the current
5364 node plus one that the current node is bounded at its upper
5365 span. Thus the test would be redundant. */
5368 node_has_high_bound (node, index_type)
5373 case_node_ptr pnode;
5375 /* If the upper bound of this node is the highest value in the type
5376 of the index expression, we need not test against it. */
5378 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5381 /* If this node has a right branch, the value at the right must be greater
5382 than that at this node, so it cannot be bounded at the top and
5383 we need not bother testing any further. */
5388 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5389 node->high, integer_one_node));
5391 /* If the addition above overflowed, we can't verify anything.
5392 Otherwise, look for a parent that tests our value + 1. */
5394 if (! tree_int_cst_lt (node->high, high_plus_one))
5397 for (pnode = node->parent; pnode; pnode = pnode->parent)
5398 if (tree_int_cst_equal (high_plus_one, pnode->low))
5404 /* Search the parent sections of the
5405 case node tree to see if both tests for the upper and lower
5406 bounds of NODE would be redundant. */
5409 node_is_bounded (node, index_type)
5413 return (node_has_low_bound (node, index_type)
5414 && node_has_high_bound (node, index_type));
5417 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5420 emit_jump_if_reachable (label)
5423 if (GET_CODE (get_last_insn ()) != BARRIER)
5427 /* Emit step-by-step code to select a case for the value of INDEX.
5428 The thus generated decision tree follows the form of the
5429 case-node binary tree NODE, whose nodes represent test conditions.
5430 INDEX_TYPE is the type of the index of the switch.
5432 Care is taken to prune redundant tests from the decision tree
5433 by detecting any boundary conditions already checked by
5434 emitted rtx. (See node_has_high_bound, node_has_low_bound
5435 and node_is_bounded, above.)
5437 Where the test conditions can be shown to be redundant we emit
5438 an unconditional jump to the target code. As a further
5439 optimization, the subordinates of a tree node are examined to
5440 check for bounded nodes. In this case conditional and/or
5441 unconditional jumps as a result of the boundary check for the
5442 current node are arranged to target the subordinates associated
5443 code for out of bound conditions on the current node node.
5445 We can assume that when control reaches the code generated here,
5446 the index value has already been compared with the parents
5447 of this node, and determined to be on the same side of each parent
5448 as this node is. Thus, if this node tests for the value 51,
5449 and a parent tested for 52, we don't need to consider
5450 the possibility of a value greater than 51. If another parent
5451 tests for the value 50, then this node need not test anything. */
5454 emit_case_nodes (index, node, default_label, index_type)
5460 /* If INDEX has an unsigned type, we must make unsigned branches. */
5461 int unsignedp = TREE_UNSIGNED (index_type);
5462 typedef rtx rtx_function ();
5463 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5464 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5465 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5466 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5467 enum machine_mode mode = GET_MODE (index);
5469 /* See if our parents have already tested everything for us.
5470 If they have, emit an unconditional jump for this node. */
5471 if (node_is_bounded (node, index_type))
5472 emit_jump (label_rtx (node->code_label));
5474 else if (tree_int_cst_equal (node->low, node->high))
5476 /* Node is single valued. First see if the index expression matches
5477 this node and then check our children, if any. */
5479 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5480 label_rtx (node->code_label), unsignedp);
5482 if (node->right != 0 && node->left != 0)
5484 /* This node has children on both sides.
5485 Dispatch to one side or the other
5486 by comparing the index value with this node's value.
5487 If one subtree is bounded, check that one first,
5488 so we can avoid real branches in the tree. */
5490 if (node_is_bounded (node->right, index_type))
5492 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5494 GT, NULL_RTX, mode, unsignedp, 0);
5496 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5497 emit_case_nodes (index, node->left, default_label, index_type);
5500 else if (node_is_bounded (node->left, index_type))
5502 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5504 LT, NULL_RTX, mode, unsignedp, 0);
5505 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5506 emit_case_nodes (index, node->right, default_label, index_type);
5511 /* Neither node is bounded. First distinguish the two sides;
5512 then emit the code for one side at a time. */
5515 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5517 /* See if the value is on the right. */
5518 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5520 GT, NULL_RTX, mode, unsignedp, 0);
5521 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5523 /* Value must be on the left.
5524 Handle the left-hand subtree. */
5525 emit_case_nodes (index, node->left, default_label, index_type);
5526 /* If left-hand subtree does nothing,
5528 emit_jump_if_reachable (default_label);
5530 /* Code branches here for the right-hand subtree. */
5531 expand_label (test_label);
5532 emit_case_nodes (index, node->right, default_label, index_type);
5536 else if (node->right != 0 && node->left == 0)
5538 /* Here we have a right child but no left so we issue conditional
5539 branch to default and process the right child.
5541 Omit the conditional branch to default if we it avoid only one
5542 right child; it costs too much space to save so little time. */
5544 if (node->right->right || node->right->left
5545 || !tree_int_cst_equal (node->right->low, node->right->high))
5547 if (!node_has_low_bound (node, index_type))
5549 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5551 LT, NULL_RTX, mode, unsignedp, 0);
5552 emit_jump_insn ((*gen_blt_pat) (default_label));
5555 emit_case_nodes (index, node->right, default_label, index_type);
5558 /* We cannot process node->right normally
5559 since we haven't ruled out the numbers less than
5560 this node's value. So handle node->right explicitly. */
5561 do_jump_if_equal (index,
5562 expand_expr (node->right->low, NULL_RTX,
5564 label_rtx (node->right->code_label), unsignedp);
5567 else if (node->right == 0 && node->left != 0)
5569 /* Just one subtree, on the left. */
5571 #if 0 /* The following code and comment were formerly part
5572 of the condition here, but they didn't work
5573 and I don't understand what the idea was. -- rms. */
5574 /* If our "most probable entry" is less probable
5575 than the default label, emit a jump to
5576 the default label using condition codes
5577 already lying around. With no right branch,
5578 a branch-greater-than will get us to the default
5581 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5584 if (node->left->left || node->left->right
5585 || !tree_int_cst_equal (node->left->low, node->left->high))
5587 if (!node_has_high_bound (node, index_type))
5589 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5591 GT, NULL_RTX, mode, unsignedp, 0);
5592 emit_jump_insn ((*gen_bgt_pat) (default_label));
5595 emit_case_nodes (index, node->left, default_label, index_type);
5598 /* We cannot process node->left normally
5599 since we haven't ruled out the numbers less than
5600 this node's value. So handle node->left explicitly. */
5601 do_jump_if_equal (index,
5602 expand_expr (node->left->low, NULL_RTX,
5604 label_rtx (node->left->code_label), unsignedp);
5609 /* Node is a range. These cases are very similar to those for a single
5610 value, except that we do not start by testing whether this node
5611 is the one to branch to. */
5613 if (node->right != 0 && node->left != 0)
5615 /* Node has subtrees on both sides.
5616 If the right-hand subtree is bounded,
5617 test for it first, since we can go straight there.
5618 Otherwise, we need to make a branch in the control structure,
5619 then handle the two subtrees. */
5620 tree test_label = 0;
5622 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5624 GT, NULL_RTX, mode, unsignedp, 0);
5626 if (node_is_bounded (node->right, index_type))
5627 /* Right hand node is fully bounded so we can eliminate any
5628 testing and branch directly to the target code. */
5629 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5632 /* Right hand node requires testing.
5633 Branch to a label where we will handle it later. */
5635 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5636 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5639 /* Value belongs to this node or to the left-hand subtree. */
5641 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5642 GE, NULL_RTX, mode, unsignedp, 0);
5643 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5645 /* Handle the left-hand subtree. */
5646 emit_case_nodes (index, node->left, default_label, index_type);
5648 /* If right node had to be handled later, do that now. */
5652 /* If the left-hand subtree fell through,
5653 don't let it fall into the right-hand subtree. */
5654 emit_jump_if_reachable (default_label);
5656 expand_label (test_label);
5657 emit_case_nodes (index, node->right, default_label, index_type);
5661 else if (node->right != 0 && node->left == 0)
5663 /* Deal with values to the left of this node,
5664 if they are possible. */
5665 if (!node_has_low_bound (node, index_type))
5667 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5669 LT, NULL_RTX, mode, unsignedp, 0);
5670 emit_jump_insn ((*gen_blt_pat) (default_label));
5673 /* Value belongs to this node or to the right-hand subtree. */
5675 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5677 LE, NULL_RTX, mode, unsignedp, 0);
5678 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5680 emit_case_nodes (index, node->right, default_label, index_type);
5683 else if (node->right == 0 && node->left != 0)
5685 /* Deal with values to the right of this node,
5686 if they are possible. */
5687 if (!node_has_high_bound (node, index_type))
5689 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5691 GT, NULL_RTX, mode, unsignedp, 0);
5692 emit_jump_insn ((*gen_bgt_pat) (default_label));
5695 /* Value belongs to this node or to the left-hand subtree. */
5697 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5698 GE, NULL_RTX, mode, unsignedp, 0);
5699 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5701 emit_case_nodes (index, node->left, default_label, index_type);
5706 /* Node has no children so we check low and high bounds to remove
5707 redundant tests. Only one of the bounds can exist,
5708 since otherwise this node is bounded--a case tested already. */
5710 if (!node_has_high_bound (node, index_type))
5712 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5714 GT, NULL_RTX, mode, unsignedp, 0);
5715 emit_jump_insn ((*gen_bgt_pat) (default_label));
5718 if (!node_has_low_bound (node, index_type))
5720 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5722 LT, NULL_RTX, mode, unsignedp, 0);
5723 emit_jump_insn ((*gen_blt_pat) (default_label));
5726 emit_jump (label_rtx (node->code_label));
5731 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5732 so that the debugging info will be correct for the unrolled loop. */
5734 /* Indexed by block number, contains a pointer to the N'th block node. */
5736 static tree *block_vector;
5739 find_loop_tree_blocks ()
5741 tree block = DECL_INITIAL (current_function_decl);
5743 /* There first block is for the function body, and does not have
5744 corresponding block notes. Don't include it in the block vector. */
5745 block = BLOCK_SUBBLOCKS (block);
5747 block_vector = identify_blocks (block, get_insns ());
5751 unroll_block_trees ()
5753 tree block = DECL_INITIAL (current_function_decl);
5755 reorder_blocks (block_vector, block, get_insns ());