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);
1624 last_expr_type = TREE_TYPE (exp);
1625 if (! flag_syntax_only)
1626 last_expr_value = expand_expr (exp,
1627 (expr_stmts_for_value
1628 ? NULL_RTX : const0_rtx),
1631 /* If all we do is reference a volatile value in memory,
1632 copy it to a register to be sure it is actually touched. */
1633 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1634 && TREE_THIS_VOLATILE (exp))
1636 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1638 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1639 copy_to_reg (last_expr_value);
1642 rtx lab = gen_label_rtx ();
1644 /* Compare the value with itself to reference it. */
1645 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1646 expand_expr (TYPE_SIZE (last_expr_type),
1647 NULL_RTX, VOIDmode, 0),
1649 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1650 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1655 /* If this expression is part of a ({...}) and is in memory, we may have
1656 to preserve temporaries. */
1657 preserve_temp_slots (last_expr_value);
1659 /* Free any temporaries used to evaluate this expression. Any temporary
1660 used as a result of this expression will already have been preserved
1667 /* Warn if EXP contains any computations whose results are not used.
1668 Return 1 if a warning is printed; 0 otherwise. */
1671 warn_if_unused_value (exp)
1674 if (TREE_USED (exp))
1677 switch (TREE_CODE (exp))
1679 case PREINCREMENT_EXPR:
1680 case POSTINCREMENT_EXPR:
1681 case PREDECREMENT_EXPR:
1682 case POSTDECREMENT_EXPR:
1687 case METHOD_CALL_EXPR:
1689 case WITH_CLEANUP_EXPR:
1691 /* We don't warn about COND_EXPR because it may be a useful
1692 construct if either arm contains a side effect. */
1697 /* For a binding, warn if no side effect within it. */
1698 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1700 case TRUTH_ORIF_EXPR:
1701 case TRUTH_ANDIF_EXPR:
1702 /* In && or ||, warn if 2nd operand has no side effect. */
1703 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1706 if (TREE_NO_UNUSED_WARNING (exp))
1708 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1710 /* Let people do `(foo (), 0)' without a warning. */
1711 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1713 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1717 case NON_LVALUE_EXPR:
1718 /* Don't warn about values cast to void. */
1719 if (TREE_TYPE (exp) == void_type_node)
1721 /* Don't warn about conversions not explicit in the user's program. */
1722 if (TREE_NO_UNUSED_WARNING (exp))
1724 /* Assignment to a cast usually results in a cast of a modify.
1725 Don't complain about that. There can be an arbitrary number of
1726 casts before the modify, so we must loop until we find the first
1727 non-cast expression and then test to see if that is a modify. */
1729 tree tem = TREE_OPERAND (exp, 0);
1731 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1732 tem = TREE_OPERAND (tem, 0);
1734 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR)
1737 /* ... fall through ... */
1740 /* Referencing a volatile value is a side effect, so don't warn. */
1741 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1742 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1743 && TREE_THIS_VOLATILE (exp))
1745 warning_with_file_and_line (emit_filename, emit_lineno,
1746 "value computed is not used");
1751 /* Clear out the memory of the last expression evaluated. */
1759 /* Begin a statement which will return a value.
1760 Return the RTL_EXPR for this statement expr.
1761 The caller must save that value and pass it to expand_end_stmt_expr. */
1764 expand_start_stmt_expr ()
1769 /* When generating bytecode just note down the stack depth */
1770 if (output_bytecode)
1771 return (build_int_2 (stack_depth, 0));
1773 /* Make the RTL_EXPR node temporary, not momentary,
1774 so that rtl_expr_chain doesn't become garbage. */
1775 momentary = suspend_momentary ();
1776 t = make_node (RTL_EXPR);
1777 resume_momentary (momentary);
1778 start_sequence_for_rtl_expr (t);
1780 expr_stmts_for_value++;
1784 /* Restore the previous state at the end of a statement that returns a value.
1785 Returns a tree node representing the statement's value and the
1786 insns to compute the value.
1788 The nodes of that expression have been freed by now, so we cannot use them.
1789 But we don't want to do that anyway; the expression has already been
1790 evaluated and now we just want to use the value. So generate a RTL_EXPR
1791 with the proper type and RTL value.
1793 If the last substatement was not an expression,
1794 return something with type `void'. */
1797 expand_end_stmt_expr (t)
1800 if (output_bytecode)
1806 /* At this point, all expressions have been evaluated in order.
1807 However, all expression values have been popped when evaluated,
1808 which means we have to recover the last expression value. This is
1809 the last value removed by means of a `drop' instruction. Instead
1810 of adding code to inhibit dropping the last expression value, it
1811 is here recovered by undoing the `drop'. Since `drop' is
1812 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1815 bc_adjust_stack (-1);
1817 if (!last_expr_type)
1818 last_expr_type = void_type_node;
1820 t = make_node (RTL_EXPR);
1821 TREE_TYPE (t) = last_expr_type;
1822 RTL_EXPR_RTL (t) = NULL;
1823 RTL_EXPR_SEQUENCE (t) = NULL;
1825 /* Don't consider deleting this expr or containing exprs at tree level. */
1826 TREE_THIS_VOLATILE (t) = 1;
1834 if (last_expr_type == 0)
1836 last_expr_type = void_type_node;
1837 last_expr_value = const0_rtx;
1839 else if (last_expr_value == 0)
1840 /* There are some cases where this can happen, such as when the
1841 statement is void type. */
1842 last_expr_value = const0_rtx;
1843 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1844 /* Remove any possible QUEUED. */
1845 last_expr_value = protect_from_queue (last_expr_value, 0);
1849 TREE_TYPE (t) = last_expr_type;
1850 RTL_EXPR_RTL (t) = last_expr_value;
1851 RTL_EXPR_SEQUENCE (t) = get_insns ();
1853 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1857 /* Don't consider deleting this expr or containing exprs at tree level. */
1858 TREE_SIDE_EFFECTS (t) = 1;
1859 /* Propagate volatility of the actual RTL expr. */
1860 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1863 expr_stmts_for_value--;
1868 /* Generate RTL for the start of an if-then. COND is the expression
1869 whose truth should be tested.
1871 If EXITFLAG is nonzero, this conditional is visible to
1872 `exit_something'. */
1875 expand_start_cond (cond, exitflag)
1879 struct nesting *thiscond = ALLOC_NESTING ();
1881 /* Make an entry on cond_stack for the cond we are entering. */
1883 thiscond->next = cond_stack;
1884 thiscond->all = nesting_stack;
1885 thiscond->depth = ++nesting_depth;
1886 thiscond->data.cond.next_label = gen_label_rtx ();
1887 /* Before we encounter an `else', we don't need a separate exit label
1888 unless there are supposed to be exit statements
1889 to exit this conditional. */
1890 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1891 thiscond->data.cond.endif_label = thiscond->exit_label;
1892 cond_stack = thiscond;
1893 nesting_stack = thiscond;
1895 if (output_bytecode)
1896 bc_expand_start_cond (cond, exitflag);
1898 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1901 /* Generate RTL between then-clause and the elseif-clause
1902 of an if-then-elseif-.... */
1905 expand_start_elseif (cond)
1908 if (cond_stack->data.cond.endif_label == 0)
1909 cond_stack->data.cond.endif_label = gen_label_rtx ();
1910 emit_jump (cond_stack->data.cond.endif_label);
1911 emit_label (cond_stack->data.cond.next_label);
1912 cond_stack->data.cond.next_label = gen_label_rtx ();
1913 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1916 /* Generate RTL between the then-clause and the else-clause
1917 of an if-then-else. */
1920 expand_start_else ()
1922 if (cond_stack->data.cond.endif_label == 0)
1923 cond_stack->data.cond.endif_label = gen_label_rtx ();
1925 if (output_bytecode)
1927 bc_expand_start_else ();
1931 emit_jump (cond_stack->data.cond.endif_label);
1932 emit_label (cond_stack->data.cond.next_label);
1933 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
1936 /* After calling expand_start_else, turn this "else" into an "else if"
1937 by providing another condition. */
1940 expand_elseif (cond)
1943 cond_stack->data.cond.next_label = gen_label_rtx ();
1944 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1947 /* Generate RTL for the end of an if-then.
1948 Pop the record for it off of cond_stack. */
1953 struct nesting *thiscond = cond_stack;
1955 if (output_bytecode)
1956 bc_expand_end_cond ();
1959 do_pending_stack_adjust ();
1960 if (thiscond->data.cond.next_label)
1961 emit_label (thiscond->data.cond.next_label);
1962 if (thiscond->data.cond.endif_label)
1963 emit_label (thiscond->data.cond.endif_label);
1966 POPSTACK (cond_stack);
1971 /* Generate code for the start of an if-then. COND is the expression
1972 whose truth is to be tested; if EXITFLAG is nonzero this conditional
1973 is to be visible to exit_something. It is assumed that the caller
1974 has pushed the previous context on the cond stack. */
1977 bc_expand_start_cond (cond, exitflag)
1981 struct nesting *thiscond = cond_stack;
1983 thiscond->data.case_stmt.nominal_type = cond;
1985 thiscond->exit_label = gen_label_rtx ();
1986 bc_expand_expr (cond);
1987 bc_emit_bytecode (xjumpifnot);
1988 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
1990 #ifdef DEBUG_PRINT_CODE
1991 fputc ('\n', stderr);
1995 /* Generate the label for the end of an if with
1999 bc_expand_end_cond ()
2001 struct nesting *thiscond = cond_stack;
2003 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2006 /* Generate code for the start of the else- clause of
2010 bc_expand_start_else ()
2012 struct nesting *thiscond = cond_stack;
2014 thiscond->data.cond.endif_label = thiscond->exit_label;
2015 thiscond->exit_label = gen_label_rtx ();
2016 bc_emit_bytecode (jump);
2017 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2019 #ifdef DEBUG_PRINT_CODE
2020 fputc ('\n', stderr);
2023 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2026 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2027 loop should be exited by `exit_something'. This is a loop for which
2028 `expand_continue' will jump to the top of the loop.
2030 Make an entry on loop_stack to record the labels associated with
2034 expand_start_loop (exit_flag)
2037 register struct nesting *thisloop = ALLOC_NESTING ();
2039 /* Make an entry on loop_stack for the loop we are entering. */
2041 thisloop->next = loop_stack;
2042 thisloop->all = nesting_stack;
2043 thisloop->depth = ++nesting_depth;
2044 thisloop->data.loop.start_label = gen_label_rtx ();
2045 thisloop->data.loop.end_label = gen_label_rtx ();
2046 thisloop->data.loop.alt_end_label = 0;
2047 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2048 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2049 loop_stack = thisloop;
2050 nesting_stack = thisloop;
2052 if (output_bytecode)
2054 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2058 do_pending_stack_adjust ();
2060 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2061 emit_label (thisloop->data.loop.start_label);
2066 /* Like expand_start_loop but for a loop where the continuation point
2067 (for expand_continue_loop) will be specified explicitly. */
2070 expand_start_loop_continue_elsewhere (exit_flag)
2073 struct nesting *thisloop = expand_start_loop (exit_flag);
2074 loop_stack->data.loop.continue_label = gen_label_rtx ();
2078 /* Specify the continuation point for a loop started with
2079 expand_start_loop_continue_elsewhere.
2080 Use this at the point in the code to which a continue statement
2084 expand_loop_continue_here ()
2086 if (output_bytecode)
2088 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2091 do_pending_stack_adjust ();
2092 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2093 emit_label (loop_stack->data.loop.continue_label);
2099 bc_expand_end_loop ()
2101 struct nesting *thisloop = loop_stack;
2103 bc_emit_bytecode (jump);
2104 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2106 #ifdef DEBUG_PRINT_CODE
2107 fputc ('\n', stderr);
2110 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2111 POPSTACK (loop_stack);
2116 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2117 Pop the block off of loop_stack. */
2123 register rtx start_label;
2124 rtx last_test_insn = 0;
2127 if (output_bytecode)
2129 bc_expand_end_loop ();
2133 insn = get_last_insn ();
2134 start_label = loop_stack->data.loop.start_label;
2136 /* Mark the continue-point at the top of the loop if none elsewhere. */
2137 if (start_label == loop_stack->data.loop.continue_label)
2138 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2140 do_pending_stack_adjust ();
2142 /* If optimizing, perhaps reorder the loop. If the loop
2143 starts with a conditional exit, roll that to the end
2144 where it will optimize together with the jump back.
2146 We look for the last conditional branch to the exit that we encounter
2147 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2148 branch to the exit first, use it.
2150 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2151 because moving them is not valid. */
2155 ! (GET_CODE (insn) == JUMP_INSN
2156 && GET_CODE (PATTERN (insn)) == SET
2157 && SET_DEST (PATTERN (insn)) == pc_rtx
2158 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2160 /* Scan insns from the top of the loop looking for a qualified
2161 conditional exit. */
2162 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2163 insn = NEXT_INSN (insn))
2165 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2168 if (GET_CODE (insn) == NOTE
2169 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2170 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2173 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2176 if (last_test_insn && num_insns > 30)
2179 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2180 && SET_DEST (PATTERN (insn)) == pc_rtx
2181 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2182 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2183 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2184 == loop_stack->data.loop.end_label)
2185 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2186 == loop_stack->data.loop.alt_end_label)))
2187 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2188 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2189 == loop_stack->data.loop.end_label)
2190 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2191 == loop_stack->data.loop.alt_end_label)))))
2192 last_test_insn = insn;
2194 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2195 && GET_CODE (PATTERN (insn)) == SET
2196 && SET_DEST (PATTERN (insn)) == pc_rtx
2197 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2198 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2199 == loop_stack->data.loop.end_label)
2200 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2201 == loop_stack->data.loop.alt_end_label)))
2202 /* Include BARRIER. */
2203 last_test_insn = NEXT_INSN (insn);
2206 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2208 /* We found one. Move everything from there up
2209 to the end of the loop, and add a jump into the loop
2210 to jump to there. */
2211 register rtx newstart_label = gen_label_rtx ();
2212 register rtx start_move = start_label;
2214 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2215 then we want to move this note also. */
2216 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2217 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2218 == NOTE_INSN_LOOP_CONT))
2219 start_move = PREV_INSN (start_move);
2221 emit_label_after (newstart_label, PREV_INSN (start_move));
2222 reorder_insns (start_move, last_test_insn, get_last_insn ());
2223 emit_jump_insn_after (gen_jump (start_label),
2224 PREV_INSN (newstart_label));
2225 emit_barrier_after (PREV_INSN (newstart_label));
2226 start_label = newstart_label;
2230 emit_jump (start_label);
2231 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2232 emit_label (loop_stack->data.loop.end_label);
2234 POPSTACK (loop_stack);
2239 /* Generate a jump to the current loop's continue-point.
2240 This is usually the top of the loop, but may be specified
2241 explicitly elsewhere. If not currently inside a loop,
2242 return 0 and do nothing; caller will print an error message. */
2245 expand_continue_loop (whichloop)
2246 struct nesting *whichloop;
2250 whichloop = loop_stack;
2253 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2258 /* Generate a jump to exit the current loop. If not currently inside a loop,
2259 return 0 and do nothing; caller will print an error message. */
2262 expand_exit_loop (whichloop)
2263 struct nesting *whichloop;
2267 whichloop = loop_stack;
2270 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2274 /* Generate a conditional jump to exit the current loop if COND
2275 evaluates to zero. If not currently inside a loop,
2276 return 0 and do nothing; caller will print an error message. */
2279 expand_exit_loop_if_false (whichloop, cond)
2280 struct nesting *whichloop;
2285 whichloop = loop_stack;
2288 if (output_bytecode)
2290 bc_expand_expr (cond);
2291 bc_expand_goto_internal (xjumpifnot,
2292 BYTECODE_BC_LABEL (whichloop->exit_label),
2297 /* In order to handle fixups, we actually create a conditional jump
2298 around a unconditional branch to exit the loop. If fixups are
2299 necessary, they go before the unconditional branch. */
2301 rtx label = gen_label_rtx ();
2304 do_jump (cond, NULL_RTX, label);
2305 last_insn = get_last_insn ();
2306 if (GET_CODE (last_insn) == CODE_LABEL)
2307 whichloop->data.loop.alt_end_label = last_insn;
2308 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2316 /* Return non-zero if we should preserve sub-expressions as separate
2317 pseudos. We never do so if we aren't optimizing. We always do so
2318 if -fexpensive-optimizations.
2320 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2321 the loop may still be a small one. */
2324 preserve_subexpressions_p ()
2328 if (flag_expensive_optimizations)
2331 if (optimize == 0 || loop_stack == 0)
2334 insn = get_last_insn_anywhere ();
2337 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2338 < n_non_fixed_regs * 3));
2342 /* Generate a jump to exit the current loop, conditional, binding contour
2343 or case statement. Not all such constructs are visible to this function,
2344 only those started with EXIT_FLAG nonzero. Individual languages use
2345 the EXIT_FLAG parameter to control which kinds of constructs you can
2348 If not currently inside anything that can be exited,
2349 return 0 and do nothing; caller will print an error message. */
2352 expand_exit_something ()
2356 for (n = nesting_stack; n; n = n->all)
2357 if (n->exit_label != 0)
2359 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2366 /* Generate RTL to return from the current function, with no value.
2367 (That is, we do not do anything about returning any value.) */
2370 expand_null_return ()
2372 struct nesting *block = block_stack;
2375 if (output_bytecode)
2377 bc_emit_instruction (ret);
2381 /* Does any pending block have cleanups? */
2383 while (block && block->data.block.cleanups == 0)
2384 block = block->next;
2386 /* If yes, use a goto to return, since that runs cleanups. */
2388 expand_null_return_1 (last_insn, block != 0);
2391 /* Generate RTL to return from the current function, with value VAL. */
2394 expand_value_return (val)
2397 struct nesting *block = block_stack;
2398 rtx last_insn = get_last_insn ();
2399 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2401 /* Copy the value to the return location
2402 unless it's already there. */
2404 if (return_reg != val)
2406 #ifdef PROMOTE_FUNCTION_RETURN
2407 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2408 int unsignedp = TREE_UNSIGNED (type);
2409 enum machine_mode mode
2410 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2413 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2414 convert_move (return_reg, val, unsignedp);
2417 emit_move_insn (return_reg, val);
2419 if (GET_CODE (return_reg) == REG
2420 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2421 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2423 /* Does any pending block have cleanups? */
2425 while (block && block->data.block.cleanups == 0)
2426 block = block->next;
2428 /* If yes, use a goto to return, since that runs cleanups.
2429 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2431 expand_null_return_1 (last_insn, block != 0);
2434 /* Output a return with no value. If LAST_INSN is nonzero,
2435 pretend that the return takes place after LAST_INSN.
2436 If USE_GOTO is nonzero then don't use a return instruction;
2437 go to the return label instead. This causes any cleanups
2438 of pending blocks to be executed normally. */
2441 expand_null_return_1 (last_insn, use_goto)
2445 rtx end_label = cleanup_label ? cleanup_label : return_label;
2447 clear_pending_stack_adjust ();
2448 do_pending_stack_adjust ();
2451 /* PCC-struct return always uses an epilogue. */
2452 if (current_function_returns_pcc_struct || use_goto)
2455 end_label = return_label = gen_label_rtx ();
2456 expand_goto_internal (NULL_TREE, end_label, last_insn);
2460 /* Otherwise output a simple return-insn if one is available,
2461 unless it won't do the job. */
2463 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2465 emit_jump_insn (gen_return ());
2471 /* Otherwise jump to the epilogue. */
2472 expand_goto_internal (NULL_TREE, end_label, last_insn);
2475 /* Generate RTL to evaluate the expression RETVAL and return it
2476 from the current function. */
2479 expand_return (retval)
2482 /* If there are any cleanups to be performed, then they will
2483 be inserted following LAST_INSN. It is desirable
2484 that the last_insn, for such purposes, should be the
2485 last insn before computing the return value. Otherwise, cleanups
2486 which call functions can clobber the return value. */
2487 /* ??? rms: I think that is erroneous, because in C++ it would
2488 run destructors on variables that might be used in the subsequent
2489 computation of the return value. */
2491 register rtx val = 0;
2495 struct nesting *block;
2497 /* Bytecode returns are quite simple, just leave the result on the
2498 arithmetic stack. */
2499 if (output_bytecode)
2501 bc_expand_expr (retval);
2502 bc_emit_instruction (ret);
2506 /* If function wants no value, give it none. */
2507 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2509 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2511 expand_null_return ();
2515 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2516 /* This is not sufficient. We also need to watch for cleanups of the
2517 expression we are about to expand. Unfortunately, we cannot know
2518 if it has cleanups until we expand it, and we want to change how we
2519 expand it depending upon if we need cleanups. We can't win. */
2521 cleanups = any_pending_cleanups (1);
2526 if (TREE_CODE (retval) == RESULT_DECL)
2527 retval_rhs = retval;
2528 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2529 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2530 retval_rhs = TREE_OPERAND (retval, 1);
2531 else if (TREE_TYPE (retval) == void_type_node)
2532 /* Recognize tail-recursive call to void function. */
2533 retval_rhs = retval;
2535 retval_rhs = NULL_TREE;
2537 /* Only use `last_insn' if there are cleanups which must be run. */
2538 if (cleanups || cleanup_label != 0)
2539 last_insn = get_last_insn ();
2541 /* Distribute return down conditional expr if either of the sides
2542 may involve tail recursion (see test below). This enhances the number
2543 of tail recursions we see. Don't do this always since it can produce
2544 sub-optimal code in some cases and we distribute assignments into
2545 conditional expressions when it would help. */
2547 if (optimize && retval_rhs != 0
2548 && frame_offset == 0
2549 && TREE_CODE (retval_rhs) == COND_EXPR
2550 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2551 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2553 rtx label = gen_label_rtx ();
2556 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2557 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2558 DECL_RESULT (current_function_decl),
2559 TREE_OPERAND (retval_rhs, 1));
2560 TREE_SIDE_EFFECTS (expr) = 1;
2561 expand_return (expr);
2564 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2565 DECL_RESULT (current_function_decl),
2566 TREE_OPERAND (retval_rhs, 2));
2567 TREE_SIDE_EFFECTS (expr) = 1;
2568 expand_return (expr);
2572 /* For tail-recursive call to current function,
2573 just jump back to the beginning.
2574 It's unsafe if any auto variable in this function
2575 has its address taken; for simplicity,
2576 require stack frame to be empty. */
2577 if (optimize && retval_rhs != 0
2578 && frame_offset == 0
2579 && TREE_CODE (retval_rhs) == CALL_EXPR
2580 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2581 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2582 /* Finish checking validity, and if valid emit code
2583 to set the argument variables for the new call. */
2584 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2585 DECL_ARGUMENTS (current_function_decl)))
2587 if (tail_recursion_label == 0)
2589 tail_recursion_label = gen_label_rtx ();
2590 emit_label_after (tail_recursion_label,
2591 tail_recursion_reentry);
2594 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2599 /* This optimization is safe if there are local cleanups
2600 because expand_null_return takes care of them.
2601 ??? I think it should also be safe when there is a cleanup label,
2602 because expand_null_return takes care of them, too.
2603 Any reason why not? */
2604 if (HAVE_return && cleanup_label == 0
2605 && ! current_function_returns_pcc_struct
2606 && BRANCH_COST <= 1)
2608 /* If this is return x == y; then generate
2609 if (x == y) return 1; else return 0;
2610 if we can do it with explicit return insns and
2611 branches are cheap. */
2613 switch (TREE_CODE (retval_rhs))
2621 case TRUTH_ANDIF_EXPR:
2622 case TRUTH_ORIF_EXPR:
2623 case TRUTH_AND_EXPR:
2625 case TRUTH_NOT_EXPR:
2626 case TRUTH_XOR_EXPR:
2627 op0 = gen_label_rtx ();
2628 jumpifnot (retval_rhs, op0);
2629 expand_value_return (const1_rtx);
2631 expand_value_return (const0_rtx);
2635 #endif /* HAVE_return */
2637 /* If the result is an aggregate that is being returned in one (or more)
2638 registers, load the registers here. The compiler currently can't handle
2639 copying a BLKmode value into registers. We could put this code in a
2640 more general area (for use by everyone instead of just function
2641 call/return), but until this feature is generally usable it is kept here
2642 (and in expand_call). */
2645 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2646 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2649 int big_endian_correction = 0;
2650 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2651 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2652 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2653 rtx result_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2654 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2655 enum machine_mode tmpmode;
2657 /* Structures smaller than a word are aligned to the least significant
2658 byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we
2659 must skip the empty high order bytes when calculating the bit
2661 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
2662 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
2664 for (i = 0; i < n_regs; i++)
2666 rtx reg = gen_reg_rtx (word_mode);
2667 rtx word = operand_subword_force (result_val, i, BLKmode);
2668 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2671 result_pseudos[i] = reg;
2673 /* Clobber REG and move each partword into it. Ensure we don't
2674 go past the end of the structure. Note that the loop below
2675 works because we've already verified that padding and
2676 endianness are compatable. */
2677 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
2680 bitpos < BITS_PER_WORD && bytes > 0;
2681 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
2683 int xbitpos = bitpos + big_endian_correction;
2685 store_bit_field (reg, bitsize, xbitpos, word_mode,
2686 extract_bit_field (word, bitsize, bitpos, 1,
2687 NULL_RTX, word_mode,
2689 bitsize / BITS_PER_UNIT,
2691 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2695 /* Now that the value is in pseudos, copy it to the result reg(s). */
2698 for (i = 0; i < n_regs; i++)
2699 emit_move_insn (gen_rtx (REG, word_mode, REGNO (result_reg) + i),
2702 /* Find the smallest integer mode large enough to hold the
2703 entire structure and use that mode instead of BLKmode
2704 on the USE insn for the return register. */
2705 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2706 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2707 tmpmode != MAX_MACHINE_MODE;
2708 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2710 /* Have we found a large enough mode? */
2711 if (GET_MODE_SIZE (tmpmode) >= bytes)
2715 /* No suitable mode found. */
2716 if (tmpmode == MAX_MACHINE_MODE)
2719 PUT_MODE (result_reg, tmpmode);
2721 expand_value_return (result_reg);
2725 && TREE_TYPE (retval_rhs) != void_type_node
2726 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2728 /* Calculate the return value into a pseudo reg. */
2729 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2731 /* All temporaries have now been used. */
2733 /* Return the calculated value, doing cleanups first. */
2734 expand_value_return (val);
2738 /* No cleanups or no hard reg used;
2739 calculate value into hard return reg. */
2740 expand_expr (retval, const0_rtx, VOIDmode, 0);
2743 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2747 /* Return 1 if the end of the generated RTX is not a barrier.
2748 This means code already compiled can drop through. */
2751 drop_through_at_end_p ()
2753 rtx insn = get_last_insn ();
2754 while (insn && GET_CODE (insn) == NOTE)
2755 insn = PREV_INSN (insn);
2756 return insn && GET_CODE (insn) != BARRIER;
2759 /* Emit code to alter this function's formal parms for a tail-recursive call.
2760 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2761 FORMALS is the chain of decls of formals.
2762 Return 1 if this can be done;
2763 otherwise return 0 and do not emit any code. */
2766 tail_recursion_args (actuals, formals)
2767 tree actuals, formals;
2769 register tree a = actuals, f = formals;
2771 register rtx *argvec;
2773 /* Check that number and types of actuals are compatible
2774 with the formals. This is not always true in valid C code.
2775 Also check that no formal needs to be addressable
2776 and that all formals are scalars. */
2778 /* Also count the args. */
2780 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2782 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2784 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2787 if (a != 0 || f != 0)
2790 /* Compute all the actuals. */
2792 argvec = (rtx *) alloca (i * sizeof (rtx));
2794 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2795 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2797 /* Find which actual values refer to current values of previous formals.
2798 Copy each of them now, before any formal is changed. */
2800 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2804 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2805 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2806 { copy = 1; break; }
2808 argvec[i] = copy_to_reg (argvec[i]);
2811 /* Store the values of the actuals into the formals. */
2813 for (f = formals, a = actuals, i = 0; f;
2814 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2816 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2817 emit_move_insn (DECL_RTL (f), argvec[i]);
2819 convert_move (DECL_RTL (f), argvec[i],
2820 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2827 /* Generate the RTL code for entering a binding contour.
2828 The variables are declared one by one, by calls to `expand_decl'.
2830 EXIT_FLAG is nonzero if this construct should be visible to
2831 `exit_something'. */
2834 expand_start_bindings (exit_flag)
2837 struct nesting *thisblock = ALLOC_NESTING ();
2838 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2840 /* Make an entry on block_stack for the block we are entering. */
2842 thisblock->next = block_stack;
2843 thisblock->all = nesting_stack;
2844 thisblock->depth = ++nesting_depth;
2845 thisblock->data.block.stack_level = 0;
2846 thisblock->data.block.cleanups = 0;
2847 thisblock->data.block.function_call_count = 0;
2851 if (block_stack->data.block.cleanups == NULL_TREE
2852 && (block_stack->data.block.outer_cleanups == NULL_TREE
2853 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2854 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2856 thisblock->data.block.outer_cleanups
2857 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2858 block_stack->data.block.outer_cleanups);
2861 thisblock->data.block.outer_cleanups = 0;
2865 && !(block_stack->data.block.cleanups == NULL_TREE
2866 && block_stack->data.block.outer_cleanups == NULL_TREE))
2867 thisblock->data.block.outer_cleanups
2868 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2869 block_stack->data.block.outer_cleanups);
2871 thisblock->data.block.outer_cleanups = 0;
2873 thisblock->data.block.label_chain = 0;
2874 thisblock->data.block.innermost_stack_block = stack_block_stack;
2875 thisblock->data.block.first_insn = note;
2876 thisblock->data.block.block_start_count = ++block_start_count;
2877 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2878 block_stack = thisblock;
2879 nesting_stack = thisblock;
2881 if (!output_bytecode)
2883 /* Make a new level for allocating stack slots. */
2888 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2889 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2893 remember_end_note (block)
2894 register tree block;
2896 BLOCK_END_NOTE (block) = last_block_end_note;
2897 last_block_end_note = NULL_RTX;
2900 /* Generate RTL code to terminate a binding contour.
2901 VARS is the chain of VAR_DECL nodes
2902 for the variables bound in this contour.
2903 MARK_ENDS is nonzero if we should put a note at the beginning
2904 and end of this binding contour.
2906 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2907 (That is true automatically if the contour has a saved stack level.) */
2910 expand_end_bindings (vars, mark_ends, dont_jump_in)
2915 register struct nesting *thisblock = block_stack;
2918 if (output_bytecode)
2920 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
2925 for (decl = vars; decl; decl = TREE_CHAIN (decl))
2926 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
2927 && ! DECL_IN_SYSTEM_HEADER (decl))
2928 warning_with_decl (decl, "unused variable `%s'");
2930 if (thisblock->exit_label)
2932 do_pending_stack_adjust ();
2933 emit_label (thisblock->exit_label);
2936 /* If necessary, make a handler for nonlocal gotos taking
2937 place in the function calls in this block. */
2938 if (function_call_count != thisblock->data.block.function_call_count
2940 /* Make handler for outermost block
2941 if there were any nonlocal gotos to this function. */
2942 && (thisblock->next == 0 ? current_function_has_nonlocal_label
2943 /* Make handler for inner block if it has something
2944 special to do when you jump out of it. */
2945 : (thisblock->data.block.cleanups != 0
2946 || thisblock->data.block.stack_level != 0)))
2949 rtx afterward = gen_label_rtx ();
2950 rtx handler_label = gen_label_rtx ();
2951 rtx save_receiver = gen_reg_rtx (Pmode);
2954 /* Don't let jump_optimize delete the handler. */
2955 LABEL_PRESERVE_P (handler_label) = 1;
2957 /* Record the handler address in the stack slot for that purpose,
2958 during this block, saving and restoring the outer value. */
2959 if (thisblock->next != 0)
2961 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
2964 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
2965 insns = get_insns ();
2967 emit_insns_before (insns, thisblock->data.block.first_insn);
2971 emit_move_insn (nonlocal_goto_handler_slot,
2972 gen_rtx (LABEL_REF, Pmode, handler_label));
2973 insns = get_insns ();
2975 emit_insns_before (insns, thisblock->data.block.first_insn);
2977 /* Jump around the handler; it runs only when specially invoked. */
2978 emit_jump (afterward);
2979 emit_label (handler_label);
2981 #ifdef HAVE_nonlocal_goto
2982 if (! HAVE_nonlocal_goto)
2984 /* First adjust our frame pointer to its actual value. It was
2985 previously set to the start of the virtual area corresponding to
2986 the stacked variables when we branched here and now needs to be
2987 adjusted to the actual hardware fp value.
2989 Assignments are to virtual registers are converted by
2990 instantiate_virtual_regs into the corresponding assignment
2991 to the underlying register (fp in this case) that makes
2992 the original assignment true.
2993 So the following insn will actually be
2994 decrementing fp by STARTING_FRAME_OFFSET. */
2995 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
2997 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
2998 if (fixed_regs[ARG_POINTER_REGNUM])
3000 #ifdef ELIMINABLE_REGS
3001 /* If the argument pointer can be eliminated in favor of the
3002 frame pointer, we don't need to restore it. We assume here
3003 that if such an elimination is present, it can always be used.
3004 This is the case on all known machines; if we don't make this
3005 assumption, we do unnecessary saving on many machines. */
3006 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3009 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3010 if (elim_regs[i].from == ARG_POINTER_REGNUM
3011 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3014 if (i == sizeof elim_regs / sizeof elim_regs [0])
3017 /* Now restore our arg pointer from the address at which it
3018 was saved in our stack frame.
3019 If there hasn't be space allocated for it yet, make
3021 if (arg_pointer_save_area == 0)
3022 arg_pointer_save_area
3023 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3024 emit_move_insn (virtual_incoming_args_rtx,
3025 /* We need a pseudo here, or else
3026 instantiate_virtual_regs_1 complains. */
3027 copy_to_reg (arg_pointer_save_area));
3032 /* The handler expects the desired label address in the static chain
3033 register. It tests the address and does an appropriate jump
3034 to whatever label is desired. */
3035 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3036 /* Skip any labels we shouldn't be able to jump to from here. */
3037 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3039 rtx not_this = gen_label_rtx ();
3040 rtx this = gen_label_rtx ();
3041 do_jump_if_equal (static_chain_rtx,
3042 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3044 emit_jump (not_this);
3046 expand_goto (TREE_VALUE (link));
3047 emit_label (not_this);
3049 /* If label is not recognized, abort. */
3050 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3052 emit_label (afterward);
3055 /* Don't allow jumping into a block that has cleanups or a stack level. */
3057 || thisblock->data.block.stack_level != 0
3058 || thisblock->data.block.cleanups != 0)
3060 struct label_chain *chain;
3062 /* Any labels in this block are no longer valid to go to.
3063 Mark them to cause an error message. */
3064 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3066 DECL_TOO_LATE (chain->label) = 1;
3067 /* If any goto without a fixup came to this label,
3068 that must be an error, because gotos without fixups
3069 come from outside all saved stack-levels and all cleanups. */
3070 if (TREE_ADDRESSABLE (chain->label))
3071 error_with_decl (chain->label,
3072 "label `%s' used before containing binding contour");
3076 /* Restore stack level in effect before the block
3077 (only if variable-size objects allocated). */
3078 /* Perform any cleanups associated with the block. */
3080 if (thisblock->data.block.stack_level != 0
3081 || thisblock->data.block.cleanups != 0)
3083 /* Only clean up here if this point can actually be reached. */
3084 if (GET_CODE (get_last_insn ()) != BARRIER)
3086 /* Don't let cleanups affect ({...}) constructs. */
3087 int old_expr_stmts_for_value = expr_stmts_for_value;
3088 rtx old_last_expr_value = last_expr_value;
3089 tree old_last_expr_type = last_expr_type;
3090 expr_stmts_for_value = 0;
3092 /* Do the cleanups. */
3093 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE);
3094 do_pending_stack_adjust ();
3096 expr_stmts_for_value = old_expr_stmts_for_value;
3097 last_expr_value = old_last_expr_value;
3098 last_expr_type = old_last_expr_type;
3100 /* Restore the stack level. */
3102 if (thisblock->data.block.stack_level != 0)
3104 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3105 thisblock->data.block.stack_level, NULL_RTX);
3106 if (nonlocal_goto_handler_slot != 0)
3107 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3112 /* Any gotos out of this block must also do these things.
3113 Also report any gotos with fixups that came to labels in this
3115 fixup_gotos (thisblock,
3116 thisblock->data.block.stack_level,
3117 thisblock->data.block.cleanups,
3118 thisblock->data.block.first_insn,
3122 /* Mark the beginning and end of the scope if requested.
3123 We do this now, after running cleanups on the variables
3124 just going out of scope, so they are in scope for their cleanups. */
3127 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3129 /* Get rid of the beginning-mark if we don't make an end-mark. */
3130 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3132 /* If doing stupid register allocation, make sure lives of all
3133 register variables declared here extend thru end of scope. */
3136 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3138 rtx rtl = DECL_RTL (decl);
3139 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3143 /* Restore block_stack level for containing block. */
3145 stack_block_stack = thisblock->data.block.innermost_stack_block;
3146 POPSTACK (block_stack);
3148 /* Pop the stack slot nesting and free any slots at this level. */
3153 /* End a binding contour.
3154 VARS is the chain of VAR_DECL nodes for the variables bound
3155 in this contour. MARK_ENDS is nonzer if we should put a note
3156 at the beginning and end of this binding contour.
3157 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3161 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3166 struct nesting *thisbind = nesting_stack;
3170 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3171 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3172 warning_with_decl (decl, "unused variable `%s'");
3174 if (thisbind->exit_label)
3175 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3177 /* Pop block/bindings off stack */
3178 POPSTACK (block_stack);
3181 /* Generate RTL for the automatic variable declaration DECL.
3182 (Other kinds of declarations are simply ignored if seen here.)
3183 CLEANUP is an expression to be executed at exit from this binding contour;
3184 for example, in C++, it might call the destructor for this variable.
3186 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3187 either before or after calling `expand_decl' but before compiling
3188 any subsequent expressions. This is because CLEANUP may be expanded
3189 more than once, on different branches of execution.
3190 For the same reason, CLEANUP may not contain a CALL_EXPR
3191 except as its topmost node--else `preexpand_calls' would get confused.
3193 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3194 that is not associated with any particular variable.
3196 There is no special support here for C++ constructors.
3197 They should be handled by the proper code in DECL_INITIAL. */
3203 struct nesting *thisblock = block_stack;
3206 if (output_bytecode)
3208 bc_expand_decl (decl, 0);
3212 type = TREE_TYPE (decl);
3214 /* Only automatic variables need any expansion done.
3215 Static and external variables, and external functions,
3216 will be handled by `assemble_variable' (called from finish_decl).
3217 TYPE_DECL and CONST_DECL require nothing.
3218 PARM_DECLs are handled in `assign_parms'. */
3220 if (TREE_CODE (decl) != VAR_DECL)
3222 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3225 /* Create the RTL representation for the variable. */
3227 if (type == error_mark_node)
3228 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3229 else if (DECL_SIZE (decl) == 0)
3230 /* Variable with incomplete type. */
3232 if (DECL_INITIAL (decl) == 0)
3233 /* Error message was already done; now avoid a crash. */
3234 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3236 /* An initializer is going to decide the size of this array.
3237 Until we know the size, represent its address with a reg. */
3238 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3240 else if (DECL_MODE (decl) != BLKmode
3241 /* If -ffloat-store, don't put explicit float vars
3243 && !(flag_float_store
3244 && TREE_CODE (type) == REAL_TYPE)
3245 && ! TREE_THIS_VOLATILE (decl)
3246 && ! TREE_ADDRESSABLE (decl)
3247 && (DECL_REGISTER (decl) || ! obey_regdecls))
3249 /* Automatic variable that can go in a register. */
3250 int unsignedp = TREE_UNSIGNED (type);
3251 enum machine_mode reg_mode
3252 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3254 if (TREE_CODE (type) == COMPLEX_TYPE)
3256 rtx realpart, imagpart;
3257 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3259 /* For a complex type variable, make a CONCAT of two pseudos
3260 so that the real and imaginary parts
3261 can be allocated separately. */
3262 realpart = gen_reg_rtx (partmode);
3263 REG_USERVAR_P (realpart) = 1;
3264 imagpart = gen_reg_rtx (partmode);
3265 REG_USERVAR_P (imagpart) = 1;
3266 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3270 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3271 if (TREE_CODE (type) == POINTER_TYPE)
3272 mark_reg_pointer (DECL_RTL (decl));
3273 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3276 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3278 /* Variable of fixed size that goes on the stack. */
3282 /* If we previously made RTL for this decl, it must be an array
3283 whose size was determined by the initializer.
3284 The old address was a register; set that register now
3285 to the proper address. */
3286 if (DECL_RTL (decl) != 0)
3288 if (GET_CODE (DECL_RTL (decl)) != MEM
3289 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3291 oldaddr = XEXP (DECL_RTL (decl), 0);
3295 = assign_stack_temp (DECL_MODE (decl),
3296 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3297 + BITS_PER_UNIT - 1)
3301 /* Set alignment we actually gave this decl. */
3302 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3303 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3307 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3308 if (addr != oldaddr)
3309 emit_move_insn (oldaddr, addr);
3312 /* If this is a memory ref that contains aggregate components,
3313 mark it as such for cse and loop optimize. */
3314 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3316 /* If this is in memory because of -ffloat-store,
3317 set the volatile bit, to prevent optimizations from
3318 undoing the effects. */
3319 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3320 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3324 /* Dynamic-size object: must push space on the stack. */
3328 /* Record the stack pointer on entry to block, if have
3329 not already done so. */
3330 if (thisblock->data.block.stack_level == 0)
3332 do_pending_stack_adjust ();
3333 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3334 &thisblock->data.block.stack_level,
3335 thisblock->data.block.first_insn);
3336 stack_block_stack = thisblock;
3339 /* Compute the variable's size, in bytes. */
3340 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3342 size_int (BITS_PER_UNIT)),
3343 NULL_RTX, VOIDmode, 0);
3346 /* Allocate space on the stack for the variable. */
3347 address = allocate_dynamic_stack_space (size, NULL_RTX,
3350 /* Reference the variable indirect through that rtx. */
3351 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3353 /* If this is a memory ref that contains aggregate components,
3354 mark it as such for cse and loop optimize. */
3355 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3357 /* Indicate the alignment we actually gave this variable. */
3358 #ifdef STACK_BOUNDARY
3359 DECL_ALIGN (decl) = STACK_BOUNDARY;
3361 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3365 if (TREE_THIS_VOLATILE (decl))
3366 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3367 #if 0 /* A variable is not necessarily unchanging
3368 just because it is const. RTX_UNCHANGING_P
3369 means no change in the function,
3370 not merely no change in the variable's scope.
3371 It is correct to set RTX_UNCHANGING_P if the variable's scope
3372 is the whole function. There's no convenient way to test that. */
3373 if (TREE_READONLY (decl))
3374 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3377 /* If doing stupid register allocation, make sure life of any
3378 register variable starts here, at the start of its scope. */
3381 use_variable (DECL_RTL (decl));
3385 /* Generate code for the automatic variable declaration DECL. For
3386 most variables this just means we give it a stack offset. The
3387 compiler sometimes emits cleanups without variables and we will
3388 have to deal with those too. */
3391 bc_expand_decl (decl, cleanup)
3399 /* A cleanup with no variable. */
3406 /* Only auto variables need any work. */
3407 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3410 type = TREE_TYPE (decl);
3412 if (type == error_mark_node)
3413 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3415 else if (DECL_SIZE (decl) == 0)
3417 /* Variable with incomplete type. The stack offset herein will be
3418 fixed later in expand_decl_init (). */
3419 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3421 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3423 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3427 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3430 /* Emit code to perform the initialization of a declaration DECL. */
3433 expand_decl_init (decl)
3436 int was_used = TREE_USED (decl);
3438 if (output_bytecode)
3440 bc_expand_decl_init (decl);
3444 /* If this is a CONST_DECL, we don't have to generate any code, but
3445 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3446 to be set while in the obstack containing the constant. If we don't
3447 do this, we can lose if we have functions nested three deep and the middle
3448 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3449 the innermost function is the first to expand that STRING_CST. */
3450 if (TREE_CODE (decl) == CONST_DECL)
3452 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3453 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3454 EXPAND_INITIALIZER);
3458 if (TREE_STATIC (decl))
3461 /* Compute and store the initial value now. */
3463 if (DECL_INITIAL (decl) == error_mark_node)
3465 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3466 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3467 || code == POINTER_TYPE)
3468 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3472 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3474 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3475 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3479 /* Don't let the initialization count as "using" the variable. */
3480 TREE_USED (decl) = was_used;
3482 /* Free any temporaries we made while initializing the decl. */
3486 /* Expand initialization for variable-sized types. Allocate array
3487 using newlocalSI and set local variable, which is a pointer to the
3491 bc_expand_variable_local_init (decl)
3494 /* Evaluate size expression and coerce to SI */
3495 bc_expand_expr (DECL_SIZE (decl));
3497 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3498 no coercion is necessary (?) */
3500 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3501 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3503 /* Emit code to allocate array */
3504 bc_emit_instruction (newlocalSI);
3506 /* Store array pointer in local variable. This is the only instance
3507 where we actually want the address of the pointer to the
3508 variable-size block, rather than the pointer itself. We avoid
3509 using expand_address() since that would cause the pointer to be
3510 pushed rather than its address. Hence the hard-coded reference;
3511 notice also that the variable is always local (no global
3512 variable-size type variables). */
3514 bc_load_localaddr (DECL_RTL (decl));
3515 bc_emit_instruction (storeP);
3519 /* Emit code to initialize a declaration. */
3522 bc_expand_decl_init (decl)
3525 int org_stack_depth;
3527 /* Statical initializers are handled elsewhere */
3529 if (TREE_STATIC (decl))
3532 /* Memory original stack depth */
3533 org_stack_depth = stack_depth;
3535 /* If the type is variable-size, we first create its space (we ASSUME
3536 it CAN'T be static). We do this regardless of whether there's an
3537 initializer assignment or not. */
3539 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3540 bc_expand_variable_local_init (decl);
3542 /* Expand initializer assignment */
3543 if (DECL_INITIAL (decl) == error_mark_node)
3545 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3547 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3548 || code == POINTER_TYPE)
3550 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3552 else if (DECL_INITIAL (decl))
3553 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3555 /* Restore stack depth */
3556 if (org_stack_depth > stack_depth)
3559 bc_adjust_stack (stack_depth - org_stack_depth);
3563 /* CLEANUP is an expression to be executed at exit from this binding contour;
3564 for example, in C++, it might call the destructor for this variable.
3566 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3567 either before or after calling `expand_decl' but before compiling
3568 any subsequent expressions. This is because CLEANUP may be expanded
3569 more than once, on different branches of execution.
3570 For the same reason, CLEANUP may not contain a CALL_EXPR
3571 except as its topmost node--else `preexpand_calls' would get confused.
3573 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3574 that is not associated with any particular variable. */
3577 expand_decl_cleanup (decl, cleanup)
3580 struct nesting *thisblock = block_stack;
3582 /* Error if we are not in any block. */
3586 /* Record the cleanup if there is one. */
3590 thisblock->data.block.cleanups
3591 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3592 /* If this block has a cleanup, it belongs in stack_block_stack. */
3593 stack_block_stack = thisblock;
3594 (*interim_eh_hook) (NULL_TREE);
3599 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3600 DECL_ELTS is the list of elements that belong to DECL's type.
3601 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3604 expand_anon_union_decl (decl, cleanup, decl_elts)
3605 tree decl, cleanup, decl_elts;
3607 struct nesting *thisblock = block_stack;
3610 expand_decl (decl, cleanup);
3611 x = DECL_RTL (decl);
3615 tree decl_elt = TREE_VALUE (decl_elts);
3616 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3617 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3619 /* Propagate the union's alignment to the elements. */
3620 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3622 /* If the element has BLKmode and the union doesn't, the union is
3623 aligned such that the element doesn't need to have BLKmode, so
3624 change the element's mode to the appropriate one for its size. */
3625 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3626 DECL_MODE (decl_elt) = mode
3627 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3630 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3631 instead create a new MEM rtx with the proper mode. */
3632 if (GET_CODE (x) == MEM)
3634 if (mode == GET_MODE (x))
3635 DECL_RTL (decl_elt) = x;
3638 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3639 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3640 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3643 else if (GET_CODE (x) == REG)
3645 if (mode == GET_MODE (x))
3646 DECL_RTL (decl_elt) = x;
3648 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3653 /* Record the cleanup if there is one. */
3656 thisblock->data.block.cleanups
3657 = temp_tree_cons (decl_elt, cleanup_elt,
3658 thisblock->data.block.cleanups);
3660 decl_elts = TREE_CHAIN (decl_elts);
3664 /* Expand a list of cleanups LIST.
3665 Elements may be expressions or may be nested lists.
3667 If DONT_DO is nonnull, then any list-element
3668 whose TREE_PURPOSE matches DONT_DO is omitted.
3669 This is sometimes used to avoid a cleanup associated with
3670 a value that is being returned out of the scope. */
3673 expand_cleanups (list, dont_do)
3678 for (tail = list; tail; tail = TREE_CHAIN (tail))
3679 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3681 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3682 expand_cleanups (TREE_VALUE (tail), dont_do);
3685 (*interim_eh_hook) (TREE_VALUE (tail));
3687 /* Cleanups may be run multiple times. For example,
3688 when exiting a binding contour, we expand the
3689 cleanups associated with that contour. When a goto
3690 within that binding contour has a target outside that
3691 contour, it will expand all cleanups from its scope to
3692 the target. Though the cleanups are expanded multiple
3693 times, the control paths are non-overlapping so the
3694 cleanups will not be executed twice. */
3695 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3701 /* Move all cleanups from the current block_stack
3702 to the containing block_stack, where they are assumed to
3703 have been created. If anything can cause a temporary to
3704 be created, but not expanded for more than one level of
3705 block_stacks, then this code will have to change. */
3710 struct nesting *block = block_stack;
3711 struct nesting *outer = block->next;
3713 outer->data.block.cleanups
3714 = chainon (block->data.block.cleanups,
3715 outer->data.block.cleanups);
3716 block->data.block.cleanups = 0;
3720 last_cleanup_this_contour ()
3722 if (block_stack == 0)
3725 return block_stack->data.block.cleanups;
3728 /* Return 1 if there are any pending cleanups at this point.
3729 If THIS_CONTOUR is nonzero, check the current contour as well.
3730 Otherwise, look only at the contours that enclose this one. */
3733 any_pending_cleanups (this_contour)
3736 struct nesting *block;
3738 if (block_stack == 0)
3741 if (this_contour && block_stack->data.block.cleanups != NULL)
3743 if (block_stack->data.block.cleanups == 0
3744 && (block_stack->data.block.outer_cleanups == 0
3746 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3751 for (block = block_stack->next; block; block = block->next)
3752 if (block->data.block.cleanups != 0)
3758 /* Enter a case (Pascal) or switch (C) statement.
3759 Push a block onto case_stack and nesting_stack
3760 to accumulate the case-labels that are seen
3761 and to record the labels generated for the statement.
3763 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3764 Otherwise, this construct is transparent for `exit_something'.
3766 EXPR is the index-expression to be dispatched on.
3767 TYPE is its nominal type. We could simply convert EXPR to this type,
3768 but instead we take short cuts. */
3771 expand_start_case (exit_flag, expr, type, printname)
3777 register struct nesting *thiscase = ALLOC_NESTING ();
3779 /* Make an entry on case_stack for the case we are entering. */
3781 thiscase->next = case_stack;
3782 thiscase->all = nesting_stack;
3783 thiscase->depth = ++nesting_depth;
3784 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3785 thiscase->data.case_stmt.case_list = 0;
3786 thiscase->data.case_stmt.index_expr = expr;
3787 thiscase->data.case_stmt.nominal_type = type;
3788 thiscase->data.case_stmt.default_label = 0;
3789 thiscase->data.case_stmt.num_ranges = 0;
3790 thiscase->data.case_stmt.printname = printname;
3791 thiscase->data.case_stmt.seenlabel = 0;
3792 case_stack = thiscase;
3793 nesting_stack = thiscase;
3795 if (output_bytecode)
3797 bc_expand_start_case (thiscase, expr, type, printname);
3801 do_pending_stack_adjust ();
3803 /* Make sure case_stmt.start points to something that won't
3804 need any transformation before expand_end_case. */
3805 if (GET_CODE (get_last_insn ()) != NOTE)
3806 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3808 thiscase->data.case_stmt.start = get_last_insn ();
3812 /* Enter a case statement. It is assumed that the caller has pushed
3813 the current context onto the case stack. */
3816 bc_expand_start_case (thiscase, expr, type, printname)
3817 struct nesting *thiscase;
3822 bc_expand_expr (expr);
3823 bc_expand_conversion (TREE_TYPE (expr), type);
3825 /* For cases, the skip is a place we jump to that's emitted after
3826 the size of the jump table is known. */
3828 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3829 bc_emit_bytecode (jump);
3830 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3832 #ifdef DEBUG_PRINT_CODE
3833 fputc ('\n', stderr);
3838 /* Start a "dummy case statement" within which case labels are invalid
3839 and are not connected to any larger real case statement.
3840 This can be used if you don't want to let a case statement jump
3841 into the middle of certain kinds of constructs. */
3844 expand_start_case_dummy ()
3846 register struct nesting *thiscase = ALLOC_NESTING ();
3848 /* Make an entry on case_stack for the dummy. */
3850 thiscase->next = case_stack;
3851 thiscase->all = nesting_stack;
3852 thiscase->depth = ++nesting_depth;
3853 thiscase->exit_label = 0;
3854 thiscase->data.case_stmt.case_list = 0;
3855 thiscase->data.case_stmt.start = 0;
3856 thiscase->data.case_stmt.nominal_type = 0;
3857 thiscase->data.case_stmt.default_label = 0;
3858 thiscase->data.case_stmt.num_ranges = 0;
3859 case_stack = thiscase;
3860 nesting_stack = thiscase;
3863 /* End a dummy case statement. */
3866 expand_end_case_dummy ()
3868 POPSTACK (case_stack);
3871 /* Return the data type of the index-expression
3872 of the innermost case statement, or null if none. */
3875 case_index_expr_type ()
3878 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3882 /* Accumulate one case or default label inside a case or switch statement.
3883 VALUE is the value of the case (a null pointer, for a default label).
3884 The function CONVERTER, when applied to arguments T and V,
3885 converts the value V to the type T.
3887 If not currently inside a case or switch statement, return 1 and do
3888 nothing. The caller will print a language-specific error message.
3889 If VALUE is a duplicate or overlaps, return 2 and do nothing
3890 except store the (first) duplicate node in *DUPLICATE.
3891 If VALUE is out of range, return 3 and do nothing.
3892 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3893 Return 0 on success.
3895 Extended to handle range statements. */
3898 pushcase (value, converter, label, duplicate)
3899 register tree value;
3900 tree (*converter) PROTO((tree, tree));
3901 register tree label;
3904 register struct case_node **l;
3905 register struct case_node *n;
3909 if (output_bytecode)
3910 return bc_pushcase (value, label);
3912 /* Fail if not inside a real case statement. */
3913 if (! (case_stack && case_stack->data.case_stmt.start))
3916 if (stack_block_stack
3917 && stack_block_stack->depth > case_stack->depth)
3920 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
3921 nominal_type = case_stack->data.case_stmt.nominal_type;
3923 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3924 if (index_type == error_mark_node)
3927 /* Convert VALUE to the type in which the comparisons are nominally done. */
3929 value = (*converter) (nominal_type, value);
3931 /* If this is the first label, warn if any insns have been emitted. */
3932 if (case_stack->data.case_stmt.seenlabel == 0)
3935 for (insn = case_stack->data.case_stmt.start;
3937 insn = NEXT_INSN (insn))
3939 if (GET_CODE (insn) == CODE_LABEL)
3941 if (GET_CODE (insn) != NOTE
3942 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
3944 warning ("unreachable code at beginning of %s",
3945 case_stack->data.case_stmt.printname);
3950 case_stack->data.case_stmt.seenlabel = 1;
3952 /* Fail if this value is out of range for the actual type of the index
3953 (which may be narrower than NOMINAL_TYPE). */
3954 if (value != 0 && ! int_fits_type_p (value, index_type))
3957 /* Fail if this is a duplicate or overlaps another entry. */
3960 if (case_stack->data.case_stmt.default_label != 0)
3962 *duplicate = case_stack->data.case_stmt.default_label;
3965 case_stack->data.case_stmt.default_label = label;
3969 /* Find the elt in the chain before which to insert the new value,
3970 to keep the chain sorted in increasing order.
3971 But report an error if this element is a duplicate. */
3972 for (l = &case_stack->data.case_stmt.case_list;
3973 /* Keep going past elements distinctly less than VALUE. */
3974 *l != 0 && tree_int_cst_lt ((*l)->high, value);
3979 /* Element we will insert before must be distinctly greater;
3980 overlap means error. */
3981 if (! tree_int_cst_lt (value, (*l)->low))
3983 *duplicate = (*l)->code_label;
3988 /* Add this label to the chain, and succeed.
3989 Copy VALUE so it is on temporary rather than momentary
3990 obstack and will thus survive till the end of the case statement. */
3991 n = (struct case_node *) oballoc (sizeof (struct case_node));
3994 n->high = n->low = copy_node (value);
3995 n->code_label = label;
3999 expand_label (label);
4003 /* Like pushcase but this case applies to all values
4004 between VALUE1 and VALUE2 (inclusive).
4005 The return value is the same as that of pushcase
4006 but there is one additional error code:
4007 4 means the specified range was empty. */
4010 pushcase_range (value1, value2, converter, label, duplicate)
4011 register tree value1, value2;
4012 tree (*converter) PROTO((tree, tree));
4013 register tree label;
4016 register struct case_node **l;
4017 register struct case_node *n;
4021 /* Fail if not inside a real case statement. */
4022 if (! (case_stack && case_stack->data.case_stmt.start))
4025 if (stack_block_stack
4026 && stack_block_stack->depth > case_stack->depth)
4029 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4030 nominal_type = case_stack->data.case_stmt.nominal_type;
4032 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4033 if (index_type == error_mark_node)
4036 /* If this is the first label, warn if any insns have been emitted. */
4037 if (case_stack->data.case_stmt.seenlabel == 0)
4040 for (insn = case_stack->data.case_stmt.start;
4042 insn = NEXT_INSN (insn))
4044 if (GET_CODE (insn) == CODE_LABEL)
4046 if (GET_CODE (insn) != NOTE
4047 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4049 warning ("unreachable code at beginning of %s",
4050 case_stack->data.case_stmt.printname);
4055 case_stack->data.case_stmt.seenlabel = 1;
4057 /* Convert VALUEs to type in which the comparisons are nominally done. */
4058 if (value1 == 0) /* Negative infinity. */
4059 value1 = TYPE_MIN_VALUE(index_type);
4060 value1 = (*converter) (nominal_type, value1);
4062 if (value2 == 0) /* Positive infinity. */
4063 value2 = TYPE_MAX_VALUE(index_type);
4064 value2 = (*converter) (nominal_type, value2);
4066 /* Fail if these values are out of range. */
4067 if (! int_fits_type_p (value1, index_type))
4070 if (! int_fits_type_p (value2, index_type))
4073 /* Fail if the range is empty. */
4074 if (tree_int_cst_lt (value2, value1))
4077 /* If the bounds are equal, turn this into the one-value case. */
4078 if (tree_int_cst_equal (value1, value2))
4079 return pushcase (value1, converter, label, duplicate);
4081 /* Find the elt in the chain before which to insert the new value,
4082 to keep the chain sorted in increasing order.
4083 But report an error if this element is a duplicate. */
4084 for (l = &case_stack->data.case_stmt.case_list;
4085 /* Keep going past elements distinctly less than this range. */
4086 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4091 /* Element we will insert before must be distinctly greater;
4092 overlap means error. */
4093 if (! tree_int_cst_lt (value2, (*l)->low))
4095 *duplicate = (*l)->code_label;
4100 /* Add this label to the chain, and succeed.
4101 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4102 obstack and will thus survive till the end of the case statement. */
4104 n = (struct case_node *) oballoc (sizeof (struct case_node));
4107 n->low = copy_node (value1);
4108 n->high = copy_node (value2);
4109 n->code_label = label;
4112 expand_label (label);
4114 case_stack->data.case_stmt.num_ranges++;
4120 /* Accumulate one case or default label; VALUE is the value of the
4121 case, or nil for a default label. If not currently inside a case,
4122 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4123 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4124 Return 0 on success. This function is a leftover from the earlier
4125 bytecode compiler, which was based on gcc 1.37. It should be
4126 merged into pushcase. */
4129 bc_pushcase (value, label)
4133 struct nesting *thiscase = case_stack;
4134 struct case_node *case_label, *new_label;
4139 /* Fail if duplicate, overlap, or out of type range. */
4142 value = convert (thiscase->data.case_stmt.nominal_type, value);
4143 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4146 for (case_label = thiscase->data.case_stmt.case_list;
4147 case_label->left; case_label = case_label->left)
4148 if (! tree_int_cst_lt (case_label->left->high, value))
4151 if (case_label != thiscase->data.case_stmt.case_list
4152 && ! tree_int_cst_lt (case_label->high, value)
4153 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4156 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4157 new_label->low = new_label->high = copy_node (value);
4158 new_label->code_label = label;
4159 new_label->left = case_label->left;
4161 case_label->left = new_label;
4162 thiscase->data.case_stmt.num_ranges++;
4166 if (thiscase->data.case_stmt.default_label)
4168 thiscase->data.case_stmt.default_label = label;
4171 expand_label (label);
4175 /* Returns the number of possible values of TYPE.
4176 Returns -1 if the number is unknown or variable.
4177 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4178 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4179 do not increase monotonically (there may be duplicates);
4180 to 1 if the values increase monotonically, but not always by 1;
4181 otherwise sets it to 0. */
4184 all_cases_count (type, spareness)
4188 HOST_WIDE_INT count, count_high = 0;
4191 switch (TREE_CODE (type))
4198 count = 1 << BITS_PER_UNIT;
4202 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4203 || TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST)
4208 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4209 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4210 but with overflow checking. */
4211 tree mint = TYPE_MIN_VALUE (type);
4212 tree maxt = TYPE_MAX_VALUE (type);
4213 HOST_WIDE_INT lo, hi;
4214 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4216 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4218 add_double (lo, hi, 1, 0, &lo, &hi);
4219 if (hi != 0 || lo < 0)
4226 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4228 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4229 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4230 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4231 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4235 if (*spareness == 1)
4237 tree prev = TREE_VALUE (TYPE_VALUES (type));
4238 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4240 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4245 prev = TREE_VALUE (t);
4254 #define BITARRAY_TEST(ARRAY, INDEX) \
4255 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4256 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4257 #define BITARRAY_SET(ARRAY, INDEX) \
4258 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4259 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4261 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4262 with the case values we have seen, assuming the case expression
4264 SPARSENESS is as determined by all_cases_count.
4266 The time needed is propotional to COUNT, unless
4267 SPARSENESS is 2, in which case quadratic time is needed. */
4270 mark_seen_cases (type, cases_seen, count, sparseness)
4272 unsigned char *cases_seen;
4278 tree next_node_to_try = NULL_TREE;
4279 long next_node_offset = 0;
4281 register struct case_node *n;
4282 tree val = make_node (INTEGER_CST);
4283 TREE_TYPE (val) = type;
4284 for (n = case_stack->data.case_stmt.case_list; n;
4287 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4288 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4289 while ( ! tree_int_cst_lt (n->high, val))
4291 /* Calculate (into xlo) the "offset" of the integer (val).
4292 The element with lowest value has offset 0, the next smallest
4293 element has offset 1, etc. */
4295 HOST_WIDE_INT xlo, xhi;
4297 if (sparseness == 2)
4299 /* This less efficient loop is only needed to handle
4300 duplicate case values (multiple enum constants
4301 with the same value). */
4302 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4303 t = TREE_CHAIN (t), xlo++)
4305 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4306 BITARRAY_SET (cases_seen, xlo);
4311 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4313 /* The TYPE_VALUES will be in increasing order, so
4314 starting searching where we last ended. */
4315 t = next_node_to_try;
4316 xlo = next_node_offset;
4322 t = TYPE_VALUES (type);
4325 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4327 next_node_to_try = TREE_CHAIN (t);
4328 next_node_offset = xlo + 1;
4333 if (t == next_node_to_try)
4339 t = TYPE_MIN_VALUE (type);
4341 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4345 add_double (xlo, xhi,
4346 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4350 if (xhi == 0 && xlo >= 0 && xlo < count)
4351 BITARRAY_SET (cases_seen, xlo);
4353 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4355 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4360 /* Called when the index of a switch statement is an enumerated type
4361 and there is no default label.
4363 Checks that all enumeration literals are covered by the case
4364 expressions of a switch. Also, warn if there are any extra
4365 switch cases that are *not* elements of the enumerated type.
4367 If all enumeration literals were covered by the case expressions,
4368 turn one of the expressions into the default expression since it should
4369 not be possible to fall through such a switch. */
4372 check_for_full_enumeration_handling (type)
4375 register struct case_node *n;
4376 register struct case_node **l;
4377 register tree chain;
4380 /* True iff the selector type is a numbered set mode. */
4383 /* The number of possible selector values. */
4386 /* For each possible selector value. a one iff it has been matched
4387 by a case value alternative. */
4388 unsigned char *cases_seen;
4390 /* The allocated size of cases_seen, in chars. */
4394 if (output_bytecode)
4396 bc_check_for_full_enumeration_handling (type);
4403 size = all_cases_count (type, &sparseness);
4404 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4406 if (size > 0 && size < 600000
4407 /* We deliberately use malloc here - not xmalloc. */
4408 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4411 tree v = TYPE_VALUES (type);
4412 bzero (cases_seen, bytes_needed);
4414 /* The time complexity of this code is normally O(N), where
4415 N being the number of members in the enumerated type.
4416 However, if type is a ENUMERAL_TYPE whose values do not
4417 increase monotonically, quadratic time may be needed. */
4419 mark_seen_cases (type, cases_seen, size, sparseness);
4421 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4423 if (BITARRAY_TEST(cases_seen, i) == 0)
4424 warning ("enumeration value `%s' not handled in switch",
4425 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4431 /* Now we go the other way around; we warn if there are case
4432 expressions that don't correspond to enumerators. This can
4433 occur since C and C++ don't enforce type-checking of
4434 assignments to enumeration variables. */
4437 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4439 for (chain = TYPE_VALUES (type);
4440 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4441 chain = TREE_CHAIN (chain))
4446 if (TYPE_NAME (type) == 0)
4447 warning ("case value `%d' not in enumerated type",
4448 TREE_INT_CST_LOW (n->low));
4450 warning ("case value `%d' not in enumerated type `%s'",
4451 TREE_INT_CST_LOW (n->low),
4452 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4455 : DECL_NAME (TYPE_NAME (type))));
4457 if (!tree_int_cst_equal (n->low, n->high))
4459 for (chain = TYPE_VALUES (type);
4460 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4461 chain = TREE_CHAIN (chain))
4466 if (TYPE_NAME (type) == 0)
4467 warning ("case value `%d' not in enumerated type",
4468 TREE_INT_CST_LOW (n->high));
4470 warning ("case value `%d' not in enumerated type `%s'",
4471 TREE_INT_CST_LOW (n->high),
4472 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4475 : DECL_NAME (TYPE_NAME (type))));
4481 /* ??? This optimization is disabled because it causes valid programs to
4482 fail. ANSI C does not guarantee that an expression with enum type
4483 will have a value that is the same as one of the enumation literals. */
4485 /* If all values were found as case labels, make one of them the default
4486 label. Thus, this switch will never fall through. We arbitrarily pick
4487 the last one to make the default since this is likely the most
4488 efficient choice. */
4492 for (l = &case_stack->data.case_stmt.case_list;
4497 case_stack->data.case_stmt.default_label = (*l)->code_label;
4504 /* Check that all enumeration literals are covered by the case
4505 expressions of a switch. Also warn if there are any cases
4506 that are not elements of the enumerated type. */
4509 bc_check_for_full_enumeration_handling (type)
4512 struct nesting *thiscase = case_stack;
4513 struct case_node *c;
4516 /* Check for enums not handled. */
4517 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4519 for (c = thiscase->data.case_stmt.case_list->left;
4520 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4523 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4524 warning ("enumerated value `%s' not handled in switch",
4525 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4528 /* Check for cases not in the enumeration. */
4529 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4531 for (e = TYPE_VALUES (type);
4532 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4536 warning ("case value `%d' not in enumerated type `%s'",
4537 TREE_INT_CST_LOW (c->low),
4538 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4540 : DECL_NAME (TYPE_NAME (type))));
4544 /* Terminate a case (Pascal) or switch (C) statement
4545 in which ORIG_INDEX is the expression to be tested.
4546 Generate the code to test it and jump to the right place. */
4549 expand_end_case (orig_index)
4552 tree minval, maxval, range, orig_minval;
4553 rtx default_label = 0;
4554 register struct case_node *n;
4562 register struct nesting *thiscase = case_stack;
4563 tree index_expr, index_type;
4566 if (output_bytecode)
4568 bc_expand_end_case (orig_index);
4572 table_label = gen_label_rtx ();
4573 index_expr = thiscase->data.case_stmt.index_expr;
4574 index_type = TREE_TYPE (index_expr);
4575 unsignedp = TREE_UNSIGNED (index_type);
4577 do_pending_stack_adjust ();
4579 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4580 if (index_type != error_mark_node)
4582 /* If switch expression was an enumerated type, check that all
4583 enumeration literals are covered by the cases.
4584 No sense trying this if there's a default case, however. */
4586 if (!thiscase->data.case_stmt.default_label
4587 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4588 && TREE_CODE (index_expr) != INTEGER_CST)
4589 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4591 /* If this is the first label, warn if any insns have been emitted. */
4592 if (thiscase->data.case_stmt.seenlabel == 0)
4595 for (insn = get_last_insn ();
4596 insn != case_stack->data.case_stmt.start;
4597 insn = PREV_INSN (insn))
4598 if (GET_CODE (insn) != NOTE
4599 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4601 warning ("unreachable code at beginning of %s",
4602 case_stack->data.case_stmt.printname);
4607 /* If we don't have a default-label, create one here,
4608 after the body of the switch. */
4609 if (thiscase->data.case_stmt.default_label == 0)
4611 thiscase->data.case_stmt.default_label
4612 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4613 expand_label (thiscase->data.case_stmt.default_label);
4615 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4617 before_case = get_last_insn ();
4619 /* Simplify the case-list before we count it. */
4620 group_case_nodes (thiscase->data.case_stmt.case_list);
4622 /* Get upper and lower bounds of case values.
4623 Also convert all the case values to the index expr's data type. */
4626 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4628 /* Check low and high label values are integers. */
4629 if (TREE_CODE (n->low) != INTEGER_CST)
4631 if (TREE_CODE (n->high) != INTEGER_CST)
4634 n->low = convert (index_type, n->low);
4635 n->high = convert (index_type, n->high);
4637 /* Count the elements and track the largest and smallest
4638 of them (treating them as signed even if they are not). */
4646 if (INT_CST_LT (n->low, minval))
4648 if (INT_CST_LT (maxval, n->high))
4651 /* A range counts double, since it requires two compares. */
4652 if (! tree_int_cst_equal (n->low, n->high))
4656 orig_minval = minval;
4658 /* Compute span of values. */
4660 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4664 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4666 emit_jump (default_label);
4669 /* If range of values is much bigger than number of values,
4670 make a sequence of conditional branches instead of a dispatch.
4671 If the switch-index is a constant, do it this way
4672 because we can optimize it. */
4674 #ifndef CASE_VALUES_THRESHOLD
4676 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4678 /* If machine does not have a case insn that compares the
4679 bounds, this means extra overhead for dispatch tables
4680 which raises the threshold for using them. */
4681 #define CASE_VALUES_THRESHOLD 5
4682 #endif /* HAVE_casesi */
4683 #endif /* CASE_VALUES_THRESHOLD */
4685 else if (TREE_INT_CST_HIGH (range) != 0
4686 || count < CASE_VALUES_THRESHOLD
4687 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4689 || TREE_CODE (index_expr) == INTEGER_CST
4690 /* These will reduce to a constant. */
4691 || (TREE_CODE (index_expr) == CALL_EXPR
4692 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4693 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4694 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4695 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4696 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4698 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4700 /* If the index is a short or char that we do not have
4701 an insn to handle comparisons directly, convert it to
4702 a full integer now, rather than letting each comparison
4703 generate the conversion. */
4705 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4706 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4707 == CODE_FOR_nothing))
4709 enum machine_mode wider_mode;
4710 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4711 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4712 if (cmp_optab->handlers[(int) wider_mode].insn_code
4713 != CODE_FOR_nothing)
4715 index = convert_to_mode (wider_mode, index, unsignedp);
4721 do_pending_stack_adjust ();
4723 index = protect_from_queue (index, 0);
4724 if (GET_CODE (index) == MEM)
4725 index = copy_to_reg (index);
4726 if (GET_CODE (index) == CONST_INT
4727 || TREE_CODE (index_expr) == INTEGER_CST)
4729 /* Make a tree node with the proper constant value
4730 if we don't already have one. */
4731 if (TREE_CODE (index_expr) != INTEGER_CST)
4734 = build_int_2 (INTVAL (index),
4735 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4736 index_expr = convert (index_type, index_expr);
4739 /* For constant index expressions we need only
4740 issue a unconditional branch to the appropriate
4741 target code. The job of removing any unreachable
4742 code is left to the optimisation phase if the
4743 "-O" option is specified. */
4744 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4745 if (! tree_int_cst_lt (index_expr, n->low)
4746 && ! tree_int_cst_lt (n->high, index_expr))
4750 emit_jump (label_rtx (n->code_label));
4752 emit_jump (default_label);
4756 /* If the index expression is not constant we generate
4757 a binary decision tree to select the appropriate
4758 target code. This is done as follows:
4760 The list of cases is rearranged into a binary tree,
4761 nearly optimal assuming equal probability for each case.
4763 The tree is transformed into RTL, eliminating
4764 redundant test conditions at the same time.
4766 If program flow could reach the end of the
4767 decision tree an unconditional jump to the
4768 default code is emitted. */
4771 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4772 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4773 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4775 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4776 default_label, index_type);
4777 emit_jump_if_reachable (default_label);
4786 enum machine_mode index_mode = SImode;
4787 int index_bits = GET_MODE_BITSIZE (index_mode);
4789 enum machine_mode op_mode;
4791 /* Convert the index to SImode. */
4792 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4793 > GET_MODE_BITSIZE (index_mode))
4795 enum machine_mode omode = TYPE_MODE (index_type);
4796 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4798 /* We must handle the endpoints in the original mode. */
4799 index_expr = build (MINUS_EXPR, index_type,
4800 index_expr, minval);
4801 minval = integer_zero_node;
4802 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4803 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4804 emit_jump_insn (gen_bltu (default_label));
4805 /* Now we can safely truncate. */
4806 index = convert_to_mode (index_mode, index, 0);
4810 if (TYPE_MODE (index_type) != index_mode)
4812 index_expr = convert (type_for_size (index_bits, 0),
4814 index_type = TREE_TYPE (index_expr);
4817 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4820 index = protect_from_queue (index, 0);
4821 do_pending_stack_adjust ();
4823 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4824 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4826 index = copy_to_mode_reg (op_mode, index);
4828 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4830 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4831 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4833 op1 = copy_to_mode_reg (op_mode, op1);
4835 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4837 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4838 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4840 op2 = copy_to_mode_reg (op_mode, op2);
4842 emit_jump_insn (gen_casesi (index, op1, op2,
4843 table_label, default_label));
4847 #ifdef HAVE_tablejump
4848 if (! win && HAVE_tablejump)
4850 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4851 fold (build (MINUS_EXPR, index_type,
4852 index_expr, minval)));
4853 index_type = TREE_TYPE (index_expr);
4854 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4856 index = protect_from_queue (index, 0);
4857 do_pending_stack_adjust ();
4859 do_tablejump (index, TYPE_MODE (index_type),
4860 expand_expr (range, NULL_RTX, VOIDmode, 0),
4861 table_label, default_label);
4868 /* Get table of labels to jump to, in order of case index. */
4870 ncases = TREE_INT_CST_LOW (range) + 1;
4871 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4872 bzero ((char *) labelvec, ncases * sizeof (rtx));
4874 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4876 register HOST_WIDE_INT i
4877 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4882 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4883 if (i + TREE_INT_CST_LOW (orig_minval)
4884 == TREE_INT_CST_LOW (n->high))
4890 /* Fill in the gaps with the default. */
4891 for (i = 0; i < ncases; i++)
4892 if (labelvec[i] == 0)
4893 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4895 /* Output the table */
4896 emit_label (table_label);
4898 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
4899 were an expression, instead of an #ifdef/#ifndef. */
4901 #ifdef CASE_VECTOR_PC_RELATIVE
4905 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
4906 gen_rtx (LABEL_REF, Pmode, table_label),
4907 gen_rtvec_v (ncases, labelvec)));
4909 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
4910 gen_rtvec_v (ncases, labelvec)));
4912 /* If the case insn drops through the table,
4913 after the table we must jump to the default-label.
4914 Otherwise record no drop-through after the table. */
4915 #ifdef CASE_DROPS_THROUGH
4916 emit_jump (default_label);
4922 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
4923 reorder_insns (before_case, get_last_insn (),
4924 thiscase->data.case_stmt.start);
4927 if (thiscase->exit_label)
4928 emit_label (thiscase->exit_label);
4930 POPSTACK (case_stack);
4936 /* Terminate a case statement. EXPR is the original index
4940 bc_expand_end_case (expr)
4943 struct nesting *thiscase = case_stack;
4944 enum bytecode_opcode opcode;
4945 struct bc_label *jump_label;
4946 struct case_node *c;
4948 bc_emit_bytecode (jump);
4949 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
4951 #ifdef DEBUG_PRINT_CODE
4952 fputc ('\n', stderr);
4955 /* Now that the size of the jump table is known, emit the actual
4956 indexed jump instruction. */
4957 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
4959 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
4960 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
4961 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
4963 bc_emit_bytecode (opcode);
4965 /* Now emit the case instructions literal arguments, in order.
4966 In addition to the value on the stack, it uses:
4967 1. The address of the jump table.
4968 2. The size of the jump table.
4969 3. The default label. */
4971 jump_label = bc_get_bytecode_label ();
4972 bc_emit_bytecode_labelref (jump_label);
4973 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
4974 sizeof thiscase->data.case_stmt.num_ranges);
4976 if (thiscase->data.case_stmt.default_label)
4977 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
4979 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
4981 /* Output the jump table. */
4983 bc_align_bytecode (3 /* PTR_ALIGN */);
4984 bc_emit_bytecode_labeldef (jump_label);
4986 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
4987 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4989 opcode = TREE_INT_CST_LOW (c->low);
4990 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
4992 opcode = TREE_INT_CST_LOW (c->high);
4993 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
4995 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
4998 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
4999 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5001 bc_emit_bytecode_DI_const (c->low);
5002 bc_emit_bytecode_DI_const (c->high);
5004 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5011 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5013 /* Possibly issue enumeration warnings. */
5015 if (!thiscase->data.case_stmt.default_label
5016 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5017 && TREE_CODE (expr) != INTEGER_CST
5019 check_for_full_enumeration_handling (TREE_TYPE (expr));
5022 #ifdef DEBUG_PRINT_CODE
5023 fputc ('\n', stderr);
5026 POPSTACK (case_stack);
5030 /* Return unique bytecode ID. */
5035 static int bc_uid = 0;
5040 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5043 do_jump_if_equal (op1, op2, label, unsignedp)
5044 rtx op1, op2, label;
5047 if (GET_CODE (op1) == CONST_INT
5048 && GET_CODE (op2) == CONST_INT)
5050 if (INTVAL (op1) == INTVAL (op2))
5055 enum machine_mode mode = GET_MODE (op1);
5056 if (mode == VOIDmode)
5057 mode = GET_MODE (op2);
5058 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5059 emit_jump_insn (gen_beq (label));
5063 /* Not all case values are encountered equally. This function
5064 uses a heuristic to weight case labels, in cases where that
5065 looks like a reasonable thing to do.
5067 Right now, all we try to guess is text, and we establish the
5070 chars above space: 16
5079 If we find any cases in the switch that are not either -1 or in the range
5080 of valid ASCII characters, or are control characters other than those
5081 commonly used with "\", don't treat this switch scanning text.
5083 Return 1 if these nodes are suitable for cost estimation, otherwise
5087 estimate_case_costs (node)
5090 tree min_ascii = build_int_2 (-1, -1);
5091 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5095 /* If we haven't already made the cost table, make it now. Note that the
5096 lower bound of the table is -1, not zero. */
5098 if (cost_table == NULL)
5100 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5101 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5103 for (i = 0; i < 128; i++)
5107 else if (ispunct (i))
5109 else if (iscntrl (i))
5113 cost_table[' '] = 8;
5114 cost_table['\t'] = 4;
5115 cost_table['\0'] = 4;
5116 cost_table['\n'] = 2;
5117 cost_table['\f'] = 1;
5118 cost_table['\v'] = 1;
5119 cost_table['\b'] = 1;
5122 /* See if all the case expressions look like text. It is text if the
5123 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5124 as signed arithmetic since we don't want to ever access cost_table with a
5125 value less than -1. Also check that none of the constants in a range
5126 are strange control characters. */
5128 for (n = node; n; n = n->right)
5130 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5133 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5134 if (cost_table[i] < 0)
5138 /* All interesting values are within the range of interesting
5139 ASCII characters. */
5143 /* Scan an ordered list of case nodes
5144 combining those with consecutive values or ranges.
5146 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5149 group_case_nodes (head)
5152 case_node_ptr node = head;
5156 rtx lb = next_real_insn (label_rtx (node->code_label));
5157 case_node_ptr np = node;
5159 /* Try to group the successors of NODE with NODE. */
5160 while (((np = np->right) != 0)
5161 /* Do they jump to the same place? */
5162 && next_real_insn (label_rtx (np->code_label)) == lb
5163 /* Are their ranges consecutive? */
5164 && tree_int_cst_equal (np->low,
5165 fold (build (PLUS_EXPR,
5166 TREE_TYPE (node->high),
5169 /* An overflow is not consecutive. */
5170 && tree_int_cst_lt (node->high,
5171 fold (build (PLUS_EXPR,
5172 TREE_TYPE (node->high),
5174 integer_one_node))))
5176 node->high = np->high;
5178 /* NP is the first node after NODE which can't be grouped with it.
5179 Delete the nodes in between, and move on to that node. */
5185 /* Take an ordered list of case nodes
5186 and transform them into a near optimal binary tree,
5187 on the assumption that any target code selection value is as
5188 likely as any other.
5190 The transformation is performed by splitting the ordered
5191 list into two equal sections plus a pivot. The parts are
5192 then attached to the pivot as left and right branches. Each
5193 branch is is then transformed recursively. */
5196 balance_case_nodes (head, parent)
5197 case_node_ptr *head;
5198 case_node_ptr parent;
5200 register case_node_ptr np;
5208 register case_node_ptr *npp;
5211 /* Count the number of entries on branch. Also count the ranges. */
5215 if (!tree_int_cst_equal (np->low, np->high))
5219 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5223 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5231 /* Split this list if it is long enough for that to help. */
5236 /* Find the place in the list that bisects the list's total cost,
5237 Here I gets half the total cost. */
5242 /* Skip nodes while their cost does not reach that amount. */
5243 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5244 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5245 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5248 npp = &(*npp)->right;
5253 /* Leave this branch lopsided, but optimize left-hand
5254 side and fill in `parent' fields for right-hand side. */
5256 np->parent = parent;
5257 balance_case_nodes (&np->left, np);
5258 for (; np->right; np = np->right)
5259 np->right->parent = np;
5263 /* If there are just three nodes, split at the middle one. */
5265 npp = &(*npp)->right;
5268 /* Find the place in the list that bisects the list's total cost,
5269 where ranges count as 2.
5270 Here I gets half the total cost. */
5271 i = (i + ranges + 1) / 2;
5274 /* Skip nodes while their cost does not reach that amount. */
5275 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5280 npp = &(*npp)->right;
5285 np->parent = parent;
5288 /* Optimize each of the two split parts. */
5289 balance_case_nodes (&np->left, np);
5290 balance_case_nodes (&np->right, np);
5294 /* Else leave this branch as one level,
5295 but fill in `parent' fields. */
5297 np->parent = parent;
5298 for (; np->right; np = np->right)
5299 np->right->parent = np;
5304 /* Search the parent sections of the case node tree
5305 to see if a test for the lower bound of NODE would be redundant.
5306 INDEX_TYPE is the type of the index expression.
5308 The instructions to generate the case decision tree are
5309 output in the same order as nodes are processed so it is
5310 known that if a parent node checks the range of the current
5311 node minus one that the current node is bounded at its lower
5312 span. Thus the test would be redundant. */
5315 node_has_low_bound (node, index_type)
5320 case_node_ptr pnode;
5322 /* If the lower bound of this node is the lowest value in the index type,
5323 we need not test it. */
5325 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5328 /* If this node has a left branch, the value at the left must be less
5329 than that at this node, so it cannot be bounded at the bottom and
5330 we need not bother testing any further. */
5335 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5336 node->low, integer_one_node));
5338 /* If the subtraction above overflowed, we can't verify anything.
5339 Otherwise, look for a parent that tests our value - 1. */
5341 if (! tree_int_cst_lt (low_minus_one, node->low))
5344 for (pnode = node->parent; pnode; pnode = pnode->parent)
5345 if (tree_int_cst_equal (low_minus_one, pnode->high))
5351 /* Search the parent sections of the case node tree
5352 to see if a test for the upper bound of NODE would be redundant.
5353 INDEX_TYPE is the type of the index expression.
5355 The instructions to generate the case decision tree are
5356 output in the same order as nodes are processed so it is
5357 known that if a parent node checks the range of the current
5358 node plus one that the current node is bounded at its upper
5359 span. Thus the test would be redundant. */
5362 node_has_high_bound (node, index_type)
5367 case_node_ptr pnode;
5369 /* If the upper bound of this node is the highest value in the type
5370 of the index expression, we need not test against it. */
5372 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5375 /* If this node has a right branch, the value at the right must be greater
5376 than that at this node, so it cannot be bounded at the top and
5377 we need not bother testing any further. */
5382 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5383 node->high, integer_one_node));
5385 /* If the addition above overflowed, we can't verify anything.
5386 Otherwise, look for a parent that tests our value + 1. */
5388 if (! tree_int_cst_lt (node->high, high_plus_one))
5391 for (pnode = node->parent; pnode; pnode = pnode->parent)
5392 if (tree_int_cst_equal (high_plus_one, pnode->low))
5398 /* Search the parent sections of the
5399 case node tree to see if both tests for the upper and lower
5400 bounds of NODE would be redundant. */
5403 node_is_bounded (node, index_type)
5407 return (node_has_low_bound (node, index_type)
5408 && node_has_high_bound (node, index_type));
5411 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5414 emit_jump_if_reachable (label)
5417 if (GET_CODE (get_last_insn ()) != BARRIER)
5421 /* Emit step-by-step code to select a case for the value of INDEX.
5422 The thus generated decision tree follows the form of the
5423 case-node binary tree NODE, whose nodes represent test conditions.
5424 INDEX_TYPE is the type of the index of the switch.
5426 Care is taken to prune redundant tests from the decision tree
5427 by detecting any boundary conditions already checked by
5428 emitted rtx. (See node_has_high_bound, node_has_low_bound
5429 and node_is_bounded, above.)
5431 Where the test conditions can be shown to be redundant we emit
5432 an unconditional jump to the target code. As a further
5433 optimization, the subordinates of a tree node are examined to
5434 check for bounded nodes. In this case conditional and/or
5435 unconditional jumps as a result of the boundary check for the
5436 current node are arranged to target the subordinates associated
5437 code for out of bound conditions on the current node node.
5439 We can assume that when control reaches the code generated here,
5440 the index value has already been compared with the parents
5441 of this node, and determined to be on the same side of each parent
5442 as this node is. Thus, if this node tests for the value 51,
5443 and a parent tested for 52, we don't need to consider
5444 the possibility of a value greater than 51. If another parent
5445 tests for the value 50, then this node need not test anything. */
5448 emit_case_nodes (index, node, default_label, index_type)
5454 /* If INDEX has an unsigned type, we must make unsigned branches. */
5455 int unsignedp = TREE_UNSIGNED (index_type);
5456 typedef rtx rtx_function ();
5457 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5458 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5459 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5460 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5461 enum machine_mode mode = GET_MODE (index);
5463 /* See if our parents have already tested everything for us.
5464 If they have, emit an unconditional jump for this node. */
5465 if (node_is_bounded (node, index_type))
5466 emit_jump (label_rtx (node->code_label));
5468 else if (tree_int_cst_equal (node->low, node->high))
5470 /* Node is single valued. First see if the index expression matches
5471 this node and then check our children, if any. */
5473 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5474 label_rtx (node->code_label), unsignedp);
5476 if (node->right != 0 && node->left != 0)
5478 /* This node has children on both sides.
5479 Dispatch to one side or the other
5480 by comparing the index value with this node's value.
5481 If one subtree is bounded, check that one first,
5482 so we can avoid real branches in the tree. */
5484 if (node_is_bounded (node->right, index_type))
5486 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5488 GT, NULL_RTX, mode, unsignedp, 0);
5490 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5491 emit_case_nodes (index, node->left, default_label, index_type);
5494 else if (node_is_bounded (node->left, index_type))
5496 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5498 LT, NULL_RTX, mode, unsignedp, 0);
5499 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5500 emit_case_nodes (index, node->right, default_label, index_type);
5505 /* Neither node is bounded. First distinguish the two sides;
5506 then emit the code for one side at a time. */
5509 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5511 /* See if the value is on the right. */
5512 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5514 GT, NULL_RTX, mode, unsignedp, 0);
5515 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5517 /* Value must be on the left.
5518 Handle the left-hand subtree. */
5519 emit_case_nodes (index, node->left, default_label, index_type);
5520 /* If left-hand subtree does nothing,
5522 emit_jump_if_reachable (default_label);
5524 /* Code branches here for the right-hand subtree. */
5525 expand_label (test_label);
5526 emit_case_nodes (index, node->right, default_label, index_type);
5530 else if (node->right != 0 && node->left == 0)
5532 /* Here we have a right child but no left so we issue conditional
5533 branch to default and process the right child.
5535 Omit the conditional branch to default if we it avoid only one
5536 right child; it costs too much space to save so little time. */
5538 if (node->right->right || node->right->left
5539 || !tree_int_cst_equal (node->right->low, node->right->high))
5541 if (!node_has_low_bound (node, index_type))
5543 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5545 LT, NULL_RTX, mode, unsignedp, 0);
5546 emit_jump_insn ((*gen_blt_pat) (default_label));
5549 emit_case_nodes (index, node->right, default_label, index_type);
5552 /* We cannot process node->right normally
5553 since we haven't ruled out the numbers less than
5554 this node's value. So handle node->right explicitly. */
5555 do_jump_if_equal (index,
5556 expand_expr (node->right->low, NULL_RTX,
5558 label_rtx (node->right->code_label), unsignedp);
5561 else if (node->right == 0 && node->left != 0)
5563 /* Just one subtree, on the left. */
5565 #if 0 /* The following code and comment were formerly part
5566 of the condition here, but they didn't work
5567 and I don't understand what the idea was. -- rms. */
5568 /* If our "most probable entry" is less probable
5569 than the default label, emit a jump to
5570 the default label using condition codes
5571 already lying around. With no right branch,
5572 a branch-greater-than will get us to the default
5575 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5578 if (node->left->left || node->left->right
5579 || !tree_int_cst_equal (node->left->low, node->left->high))
5581 if (!node_has_high_bound (node, index_type))
5583 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5585 GT, NULL_RTX, mode, unsignedp, 0);
5586 emit_jump_insn ((*gen_bgt_pat) (default_label));
5589 emit_case_nodes (index, node->left, default_label, index_type);
5592 /* We cannot process node->left normally
5593 since we haven't ruled out the numbers less than
5594 this node's value. So handle node->left explicitly. */
5595 do_jump_if_equal (index,
5596 expand_expr (node->left->low, NULL_RTX,
5598 label_rtx (node->left->code_label), unsignedp);
5603 /* Node is a range. These cases are very similar to those for a single
5604 value, except that we do not start by testing whether this node
5605 is the one to branch to. */
5607 if (node->right != 0 && node->left != 0)
5609 /* Node has subtrees on both sides.
5610 If the right-hand subtree is bounded,
5611 test for it first, since we can go straight there.
5612 Otherwise, we need to make a branch in the control structure,
5613 then handle the two subtrees. */
5614 tree test_label = 0;
5616 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5618 GT, NULL_RTX, mode, unsignedp, 0);
5620 if (node_is_bounded (node->right, index_type))
5621 /* Right hand node is fully bounded so we can eliminate any
5622 testing and branch directly to the target code. */
5623 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5626 /* Right hand node requires testing.
5627 Branch to a label where we will handle it later. */
5629 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5630 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5633 /* Value belongs to this node or to the left-hand subtree. */
5635 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5636 GE, NULL_RTX, mode, unsignedp, 0);
5637 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5639 /* Handle the left-hand subtree. */
5640 emit_case_nodes (index, node->left, default_label, index_type);
5642 /* If right node had to be handled later, do that now. */
5646 /* If the left-hand subtree fell through,
5647 don't let it fall into the right-hand subtree. */
5648 emit_jump_if_reachable (default_label);
5650 expand_label (test_label);
5651 emit_case_nodes (index, node->right, default_label, index_type);
5655 else if (node->right != 0 && node->left == 0)
5657 /* Deal with values to the left of this node,
5658 if they are possible. */
5659 if (!node_has_low_bound (node, index_type))
5661 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5663 LT, NULL_RTX, mode, unsignedp, 0);
5664 emit_jump_insn ((*gen_blt_pat) (default_label));
5667 /* Value belongs to this node or to the right-hand subtree. */
5669 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5671 LE, NULL_RTX, mode, unsignedp, 0);
5672 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5674 emit_case_nodes (index, node->right, default_label, index_type);
5677 else if (node->right == 0 && node->left != 0)
5679 /* Deal with values to the right of this node,
5680 if they are possible. */
5681 if (!node_has_high_bound (node, index_type))
5683 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5685 GT, NULL_RTX, mode, unsignedp, 0);
5686 emit_jump_insn ((*gen_bgt_pat) (default_label));
5689 /* Value belongs to this node or to the left-hand subtree. */
5691 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5692 GE, NULL_RTX, mode, unsignedp, 0);
5693 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5695 emit_case_nodes (index, node->left, default_label, index_type);
5700 /* Node has no children so we check low and high bounds to remove
5701 redundant tests. Only one of the bounds can exist,
5702 since otherwise this node is bounded--a case tested already. */
5704 if (!node_has_high_bound (node, index_type))
5706 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5708 GT, NULL_RTX, mode, unsignedp, 0);
5709 emit_jump_insn ((*gen_bgt_pat) (default_label));
5712 if (!node_has_low_bound (node, index_type))
5714 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5716 LT, NULL_RTX, mode, unsignedp, 0);
5717 emit_jump_insn ((*gen_blt_pat) (default_label));
5720 emit_jump (label_rtx (node->code_label));
5725 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5726 so that the debugging info will be correct for the unrolled loop. */
5728 /* Indexed by block number, contains a pointer to the N'th block node. */
5730 static tree *block_vector;
5733 find_loop_tree_blocks ()
5735 tree block = DECL_INITIAL (current_function_decl);
5737 /* There first block is for the function body, and does not have
5738 corresponding block notes. Don't include it in the block vector. */
5739 block = BLOCK_SUBBLOCKS (block);
5741 block_vector = identify_blocks (block, get_insns ());
5745 unroll_block_trees ()
5747 tree block = DECL_INITIAL (current_function_decl);
5749 reorder_blocks (block_vector, block, get_insns ());