1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92, 93, 94, 1995 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 void bc_expand_start_cond PROTO((tree, int));
442 static void bc_expand_end_cond PROTO((void));
443 static void bc_expand_start_else PROTO((void));
444 static void bc_expand_end_loop PROTO((void));
445 static void bc_expand_end_bindings PROTO((tree, int, int));
446 static void bc_expand_decl PROTO((tree, tree));
447 static void bc_expand_variable_local_init PROTO((tree));
448 static void bc_expand_decl_init PROTO((tree));
449 static void expand_null_return_1 PROTO((rtx, int));
450 static void expand_value_return PROTO((rtx));
451 static int tail_recursion_args PROTO((tree, tree));
452 static void expand_cleanups PROTO((tree, tree, int, int));
453 static void bc_expand_start_case PROTO((struct nesting *, tree,
455 static int bc_pushcase PROTO((tree, tree));
456 static void bc_check_for_full_enumeration_handling PROTO((tree));
457 static void bc_expand_end_case PROTO((tree));
458 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
459 static int estimate_case_costs PROTO((case_node_ptr));
460 static void group_case_nodes PROTO((case_node_ptr));
461 static void balance_case_nodes PROTO((case_node_ptr *,
463 static int node_has_low_bound PROTO((case_node_ptr, tree));
464 static int node_has_high_bound PROTO((case_node_ptr, tree));
465 static int node_is_bounded PROTO((case_node_ptr, tree));
466 static void emit_jump_if_reachable PROTO((rtx));
467 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
469 int bc_expand_exit_loop_if_false ();
470 void bc_expand_start_cond ();
471 void bc_expand_end_cond ();
472 void bc_expand_start_else ();
473 void bc_expand_end_bindings ();
474 void bc_expand_start_case ();
475 void bc_check_for_full_enumeration_handling ();
476 void bc_expand_end_case ();
477 void bc_expand_decl ();
479 extern rtx bc_allocate_local ();
480 extern rtx bc_allocate_variable_array ();
485 gcc_obstack_init (&stmt_obstack);
487 empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE);
492 init_stmt_for_function ()
494 /* We are not currently within any block, conditional, loop or case. */
496 stack_block_stack = 0;
503 block_start_count = 0;
505 /* No gotos have been expanded yet. */
506 goto_fixup_chain = 0;
508 /* We are not processing a ({...}) grouping. */
509 expr_stmts_for_value = 0;
517 p->block_stack = block_stack;
518 p->stack_block_stack = stack_block_stack;
519 p->cond_stack = cond_stack;
520 p->loop_stack = loop_stack;
521 p->case_stack = case_stack;
522 p->nesting_stack = nesting_stack;
523 p->nesting_depth = nesting_depth;
524 p->block_start_count = block_start_count;
525 p->last_expr_type = last_expr_type;
526 p->last_expr_value = last_expr_value;
527 p->expr_stmts_for_value = expr_stmts_for_value;
528 p->emit_filename = emit_filename;
529 p->emit_lineno = emit_lineno;
530 p->goto_fixup_chain = goto_fixup_chain;
534 restore_stmt_status (p)
537 block_stack = p->block_stack;
538 stack_block_stack = p->stack_block_stack;
539 cond_stack = p->cond_stack;
540 loop_stack = p->loop_stack;
541 case_stack = p->case_stack;
542 nesting_stack = p->nesting_stack;
543 nesting_depth = p->nesting_depth;
544 block_start_count = p->block_start_count;
545 last_expr_type = p->last_expr_type;
546 last_expr_value = p->last_expr_value;
547 expr_stmts_for_value = p->expr_stmts_for_value;
548 emit_filename = p->emit_filename;
549 emit_lineno = p->emit_lineno;
550 goto_fixup_chain = p->goto_fixup_chain;
553 /* Emit a no-op instruction. */
560 if (!output_bytecode)
562 last_insn = get_last_insn ();
564 && (GET_CODE (last_insn) == CODE_LABEL
565 || prev_real_insn (last_insn) == 0))
566 emit_insn (gen_nop ());
570 /* Return the rtx-label that corresponds to a LABEL_DECL,
571 creating it if necessary. */
577 if (TREE_CODE (label) != LABEL_DECL)
580 if (DECL_RTL (label))
581 return DECL_RTL (label);
583 return DECL_RTL (label) = gen_label_rtx ();
586 /* Add an unconditional jump to LABEL as the next sequential instruction. */
592 do_pending_stack_adjust ();
593 emit_jump_insn (gen_jump (label));
597 /* Emit code to jump to the address
598 specified by the pointer expression EXP. */
601 expand_computed_goto (exp)
606 bc_expand_expr (exp);
607 bc_emit_instruction (jumpP);
611 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
613 emit_indirect_jump (x);
617 /* Handle goto statements and the labels that they can go to. */
619 /* Specify the location in the RTL code of a label LABEL,
620 which is a LABEL_DECL tree node.
622 This is used for the kind of label that the user can jump to with a
623 goto statement, and for alternatives of a switch or case statement.
624 RTL labels generated for loops and conditionals don't go through here;
625 they are generated directly at the RTL level, by other functions below.
627 Note that this has nothing to do with defining label *names*.
628 Languages vary in how they do that and what that even means. */
634 struct label_chain *p;
638 if (! DECL_RTL (label))
639 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
640 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
641 error ("multiply defined label");
645 do_pending_stack_adjust ();
646 emit_label (label_rtx (label));
647 if (DECL_NAME (label))
648 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
650 if (stack_block_stack != 0)
652 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
653 p->next = stack_block_stack->data.block.label_chain;
654 stack_block_stack->data.block.label_chain = p;
659 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
660 from nested functions. */
663 declare_nonlocal_label (label)
666 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
667 LABEL_PRESERVE_P (label_rtx (label)) = 1;
668 if (nonlocal_goto_handler_slot == 0)
670 nonlocal_goto_handler_slot
671 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
672 emit_stack_save (SAVE_NONLOCAL,
673 &nonlocal_goto_stack_level,
674 PREV_INSN (tail_recursion_reentry));
678 /* Generate RTL code for a `goto' statement with target label LABEL.
679 LABEL should be a LABEL_DECL tree node that was or will later be
680 defined with `expand_label'. */
690 expand_goto_internal (label, label_rtx (label), NULL_RTX);
694 /* Check for a nonlocal goto to a containing function. */
695 context = decl_function_context (label);
696 if (context != 0 && context != current_function_decl)
698 struct function *p = find_function_data (context);
699 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
702 p->has_nonlocal_label = 1;
703 current_function_has_nonlocal_goto = 1;
704 LABEL_REF_NONLOCAL_P (label_ref) = 1;
706 /* Copy the rtl for the slots so that they won't be shared in
707 case the virtual stack vars register gets instantiated differently
708 in the parent than in the child. */
710 #if HAVE_nonlocal_goto
711 if (HAVE_nonlocal_goto)
712 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
713 copy_rtx (p->nonlocal_goto_handler_slot),
714 copy_rtx (p->nonlocal_goto_stack_level),
721 /* Restore frame pointer for containing function.
722 This sets the actual hard register used for the frame pointer
723 to the location of the function's incoming static chain info.
724 The non-local goto handler will then adjust it to contain the
725 proper value and reload the argument pointer, if needed. */
726 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
728 /* We have now loaded the frame pointer hardware register with
729 the address of that corresponds to the start of the virtual
730 stack vars. So replace virtual_stack_vars_rtx in all
731 addresses we use with stack_pointer_rtx. */
733 /* Get addr of containing function's current nonlocal goto handler,
734 which will do any cleanups and then jump to the label. */
735 addr = copy_rtx (p->nonlocal_goto_handler_slot);
736 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
737 hard_frame_pointer_rtx));
739 /* Restore the stack pointer. Note this uses fp just restored. */
740 addr = p->nonlocal_goto_stack_level;
742 addr = replace_rtx (copy_rtx (addr),
743 virtual_stack_vars_rtx,
744 hard_frame_pointer_rtx);
746 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
748 /* Put in the static chain register the nonlocal label address. */
749 emit_move_insn (static_chain_rtx, label_ref);
750 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
752 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
753 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
754 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
755 emit_indirect_jump (temp);
759 expand_goto_internal (label, label_rtx (label), NULL_RTX);
762 /* Generate RTL code for a `goto' statement with target label BODY.
763 LABEL should be a LABEL_REF.
764 LAST_INSN, if non-0, is the rtx we should consider as the last
765 insn emitted (for the purposes of cleaning up a return). */
768 expand_goto_internal (body, label, last_insn)
773 struct nesting *block;
776 /* NOTICE! If a bytecode instruction other than `jump' is needed,
777 then the caller has to call bc_expand_goto_internal()
778 directly. This is rather an exceptional case, and there aren't
779 that many places where this is necessary. */
782 expand_goto_internal (body, label, last_insn);
786 if (GET_CODE (label) != CODE_LABEL)
789 /* If label has already been defined, we can tell now
790 whether and how we must alter the stack level. */
792 if (PREV_INSN (label) != 0)
794 /* Find the innermost pending block that contains the label.
795 (Check containment by comparing insn-uids.)
796 Then restore the outermost stack level within that block,
797 and do cleanups of all blocks contained in it. */
798 for (block = block_stack; block; block = block->next)
800 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
802 if (block->data.block.stack_level != 0)
803 stack_level = block->data.block.stack_level;
804 /* Execute the cleanups for blocks we are exiting. */
805 if (block->data.block.cleanups != 0)
807 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
808 do_pending_stack_adjust ();
814 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
815 the stack pointer. This one should be deleted as dead by flow. */
816 clear_pending_stack_adjust ();
817 do_pending_stack_adjust ();
818 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
821 if (body != 0 && DECL_TOO_LATE (body))
822 error ("jump to `%s' invalidly jumps into binding contour",
823 IDENTIFIER_POINTER (DECL_NAME (body)));
825 /* Label not yet defined: may need to put this goto
826 on the fixup list. */
827 else if (! expand_fixup (body, label, last_insn))
829 /* No fixup needed. Record that the label is the target
830 of at least one goto that has no fixup. */
832 TREE_ADDRESSABLE (body) = 1;
838 /* Generate a jump with OPCODE to the given bytecode LABEL which is
839 found within BODY. */
842 bc_expand_goto_internal (opcode, label, body)
843 enum bytecode_opcode opcode;
844 struct bc_label *label;
847 struct nesting *block;
848 int stack_level = -1;
850 /* If the label is defined, adjust the stack as necessary.
851 If it's not defined, we have to push the reference on the
857 /* Find the innermost pending block that contains the label.
858 (Check containment by comparing bytecode uids.) Then restore the
859 outermost stack level within that block. */
861 for (block = block_stack; block; block = block->next)
863 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
865 if (block->data.block.bc_stack_level)
866 stack_level = block->data.block.bc_stack_level;
868 /* Execute the cleanups for blocks we are exiting. */
869 if (block->data.block.cleanups != 0)
871 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
872 do_pending_stack_adjust ();
876 /* Restore the stack level. If we need to adjust the stack, we
877 must do so after the jump, since the jump may depend on
878 what's on the stack. Thus, any stack-modifying conditional
879 jumps (these are the only ones that rely on what's on the
880 stack) go into the fixup list. */
883 && stack_depth != stack_level
886 bc_expand_fixup (opcode, label, stack_level);
889 if (stack_level >= 0)
890 bc_adjust_stack (stack_depth - stack_level);
892 if (body && DECL_BIT_FIELD (body))
893 error ("jump to `%s' invalidly jumps into binding contour",
894 IDENTIFIER_POINTER (DECL_NAME (body)));
896 /* Emit immediate jump */
897 bc_emit_bytecode (opcode);
898 bc_emit_bytecode_labelref (label);
900 #ifdef DEBUG_PRINT_CODE
901 fputc ('\n', stderr);
906 /* Put goto in the fixup list */
907 bc_expand_fixup (opcode, label, stack_level);
910 /* Generate if necessary a fixup for a goto
911 whose target label in tree structure (if any) is TREE_LABEL
912 and whose target in rtl is RTL_LABEL.
914 If LAST_INSN is nonzero, we pretend that the jump appears
915 after insn LAST_INSN instead of at the current point in the insn stream.
917 The fixup will be used later to insert insns just before the goto.
918 Those insns will restore the stack level as appropriate for the
919 target label, and will (in the case of C++) also invoke any object
920 destructors which have to be invoked when we exit the scopes which
921 are exited by the goto.
923 Value is nonzero if a fixup is made. */
926 expand_fixup (tree_label, rtl_label, last_insn)
931 struct nesting *block, *end_block;
933 /* See if we can recognize which block the label will be output in.
934 This is possible in some very common cases.
935 If we succeed, set END_BLOCK to that block.
936 Otherwise, set it to 0. */
939 && (rtl_label == cond_stack->data.cond.endif_label
940 || rtl_label == cond_stack->data.cond.next_label))
941 end_block = cond_stack;
942 /* If we are in a loop, recognize certain labels which
943 are likely targets. This reduces the number of fixups
944 we need to create. */
946 && (rtl_label == loop_stack->data.loop.start_label
947 || rtl_label == loop_stack->data.loop.end_label
948 || rtl_label == loop_stack->data.loop.continue_label))
949 end_block = loop_stack;
953 /* Now set END_BLOCK to the binding level to which we will return. */
957 struct nesting *next_block = end_block->all;
960 /* First see if the END_BLOCK is inside the innermost binding level.
961 If so, then no cleanups or stack levels are relevant. */
962 while (next_block && next_block != block)
963 next_block = next_block->all;
968 /* Otherwise, set END_BLOCK to the innermost binding level
969 which is outside the relevant control-structure nesting. */
970 next_block = block_stack->next;
971 for (block = block_stack; block != end_block; block = block->all)
972 if (block == next_block)
973 next_block = next_block->next;
974 end_block = next_block;
977 /* Does any containing block have a stack level or cleanups?
978 If not, no fixup is needed, and that is the normal case
979 (the only case, for standard C). */
980 for (block = block_stack; block != end_block; block = block->next)
981 if (block->data.block.stack_level != 0
982 || block->data.block.cleanups != 0)
985 if (block != end_block)
987 /* Ok, a fixup is needed. Add a fixup to the list of such. */
988 struct goto_fixup *fixup
989 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
990 /* In case an old stack level is restored, make sure that comes
991 after any pending stack adjust. */
992 /* ?? If the fixup isn't to come at the present position,
993 doing the stack adjust here isn't useful. Doing it with our
994 settings at that location isn't useful either. Let's hope
997 do_pending_stack_adjust ();
998 fixup->target = tree_label;
999 fixup->target_rtl = rtl_label;
1001 /* Create a BLOCK node and a corresponding matched set of
1002 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1003 this point. The notes will encapsulate any and all fixup
1004 code which we might later insert at this point in the insn
1005 stream. Also, the BLOCK node will be the parent (i.e. the
1006 `SUPERBLOCK') of any other BLOCK nodes which we might create
1007 later on when we are expanding the fixup code. */
1010 register rtx original_before_jump
1011 = last_insn ? last_insn : get_last_insn ();
1015 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1016 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1017 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1019 emit_insns_after (fixup->before_jump, original_before_jump);
1022 fixup->block_start_count = block_start_count;
1023 fixup->stack_level = 0;
1024 fixup->cleanup_list_list
1025 = (((block->data.block.outer_cleanups
1027 && block->data.block.outer_cleanups != empty_cleanup_list
1030 || block->data.block.cleanups)
1031 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1032 block->data.block.outer_cleanups)
1034 fixup->next = goto_fixup_chain;
1035 goto_fixup_chain = fixup;
1042 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1043 Make the fixup restore the stack level to STACK_LEVEL. */
1046 bc_expand_fixup (opcode, label, stack_level)
1047 enum bytecode_opcode opcode;
1048 struct bc_label *label;
1051 struct goto_fixup *fixup
1052 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1054 fixup->label = bc_get_bytecode_label ();
1055 fixup->bc_target = label;
1056 fixup->bc_stack_level = stack_level;
1057 fixup->bc_handled = FALSE;
1059 fixup->next = goto_fixup_chain;
1060 goto_fixup_chain = fixup;
1062 /* Insert a jump to the fixup code */
1063 bc_emit_bytecode (opcode);
1064 bc_emit_bytecode_labelref (fixup->label);
1066 #ifdef DEBUG_PRINT_CODE
1067 fputc ('\n', stderr);
1071 /* Expand any needed fixups in the outputmost binding level of the
1072 function. FIRST_INSN is the first insn in the function. */
1075 expand_fixups (first_insn)
1078 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1081 /* When exiting a binding contour, process all pending gotos requiring fixups.
1082 THISBLOCK is the structure that describes the block being exited.
1083 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1084 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1085 FIRST_INSN is the insn that began this contour.
1087 Gotos that jump out of this contour must restore the
1088 stack level and do the cleanups before actually jumping.
1090 DONT_JUMP_IN nonzero means report error there is a jump into this
1091 contour from before the beginning of the contour.
1092 This is also done if STACK_LEVEL is nonzero. */
1095 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1096 struct nesting *thisblock;
1102 register struct goto_fixup *f, *prev;
1104 if (output_bytecode)
1106 /* ??? The second arg is the bc stack level, which is not the same
1107 as STACK_LEVEL. I have no idea what should go here, so I'll
1109 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1113 /* F is the fixup we are considering; PREV is the previous one. */
1114 /* We run this loop in two passes so that cleanups of exited blocks
1115 are run first, and blocks that are exited are marked so
1118 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1120 /* Test for a fixup that is inactive because it is already handled. */
1121 if (f->before_jump == 0)
1123 /* Delete inactive fixup from the chain, if that is easy to do. */
1125 prev->next = f->next;
1127 /* Has this fixup's target label been defined?
1128 If so, we can finalize it. */
1129 else if (PREV_INSN (f->target_rtl) != 0)
1131 register rtx cleanup_insns;
1133 /* Get the first non-label after the label
1134 this goto jumps to. If that's before this scope begins,
1135 we don't have a jump into the scope. */
1136 rtx after_label = f->target_rtl;
1137 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1138 after_label = NEXT_INSN (after_label);
1140 /* If this fixup jumped into this contour from before the beginning
1141 of this contour, report an error. */
1142 /* ??? Bug: this does not detect jumping in through intermediate
1143 blocks that have stack levels or cleanups.
1144 It detects only a problem with the innermost block
1145 around the label. */
1147 && (dont_jump_in || stack_level || cleanup_list)
1148 /* If AFTER_LABEL is 0, it means the jump goes to the end
1149 of the rtl, which means it jumps into this scope. */
1150 && (after_label == 0
1151 || INSN_UID (first_insn) < INSN_UID (after_label))
1152 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1153 && ! DECL_REGISTER (f->target))
1155 error_with_decl (f->target,
1156 "label `%s' used before containing binding contour");
1157 /* Prevent multiple errors for one label. */
1158 DECL_REGISTER (f->target) = 1;
1161 /* We will expand the cleanups into a sequence of their own and
1162 then later on we will attach this new sequence to the insn
1163 stream just ahead of the actual jump insn. */
1167 /* Temporarily restore the lexical context where we will
1168 logically be inserting the fixup code. We do this for the
1169 sake of getting the debugging information right. */
1172 set_block (f->context);
1174 /* Expand the cleanups for blocks this jump exits. */
1175 if (f->cleanup_list_list)
1178 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1179 /* Marked elements correspond to blocks that have been closed.
1180 Do their cleanups. */
1181 if (TREE_ADDRESSABLE (lists)
1182 && TREE_VALUE (lists) != 0)
1184 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1185 /* Pop any pushes done in the cleanups,
1186 in case function is about to return. */
1187 do_pending_stack_adjust ();
1191 /* Restore stack level for the biggest contour that this
1192 jump jumps out of. */
1194 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1196 /* Finish up the sequence containing the insns which implement the
1197 necessary cleanups, and then attach that whole sequence to the
1198 insn stream just ahead of the actual jump insn. Attaching it
1199 at that point insures that any cleanups which are in fact
1200 implicit C++ object destructions (which must be executed upon
1201 leaving the block) appear (to the debugger) to be taking place
1202 in an area of the generated code where the object(s) being
1203 destructed are still "in scope". */
1205 cleanup_insns = get_insns ();
1209 emit_insns_after (cleanup_insns, f->before_jump);
1216 /* For any still-undefined labels, do the cleanups for this block now.
1217 We must do this now since items in the cleanup list may go out
1218 of scope when the block ends. */
1219 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1220 if (f->before_jump != 0
1221 && PREV_INSN (f->target_rtl) == 0
1222 /* Label has still not appeared. If we are exiting a block with
1223 a stack level to restore, that started before the fixup,
1224 mark this stack level as needing restoration
1225 when the fixup is later finalized. */
1227 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1228 means the label is undefined. That's erroneous, but possible. */
1229 && (thisblock->data.block.block_start_count
1230 <= f->block_start_count))
1232 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)
1242 set_block (f->context);
1243 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1244 do_pending_stack_adjust ();
1245 cleanup_insns = get_insns ();
1249 = emit_insns_after (cleanup_insns, f->before_jump);
1251 TREE_VALUE (lists) = 0;
1255 f->stack_level = stack_level;
1260 /* When exiting a binding contour, process all pending gotos requiring fixups.
1261 Note: STACK_DEPTH is not altered.
1263 The arguments are currently not used in the bytecode compiler, but we may
1264 need them one day for languages other than C.
1266 THISBLOCK is the structure that describes the block being exited.
1267 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1268 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1269 FIRST_INSN is the insn that began this contour.
1271 Gotos that jump out of this contour must restore the
1272 stack level and do the cleanups before actually jumping.
1274 DONT_JUMP_IN nonzero means report error there is a jump into this
1275 contour from before the beginning of the contour.
1276 This is also done if STACK_LEVEL is nonzero. */
1279 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1280 struct nesting *thisblock;
1286 register struct goto_fixup *f, *prev;
1287 int saved_stack_depth;
1289 /* F is the fixup we are considering; PREV is the previous one. */
1291 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1293 /* Test for a fixup that is inactive because it is already handled. */
1294 if (f->before_jump == 0)
1296 /* Delete inactive fixup from the chain, if that is easy to do. */
1298 prev->next = f->next;
1301 /* Emit code to restore the stack and continue */
1302 bc_emit_bytecode_labeldef (f->label);
1304 /* Save stack_depth across call, since bc_adjust_stack () will alter
1305 the perceived stack depth via the instructions generated. */
1307 if (f->bc_stack_level >= 0)
1309 saved_stack_depth = stack_depth;
1310 bc_adjust_stack (stack_depth - f->bc_stack_level);
1311 stack_depth = saved_stack_depth;
1314 bc_emit_bytecode (jump);
1315 bc_emit_bytecode_labelref (f->bc_target);
1317 #ifdef DEBUG_PRINT_CODE
1318 fputc ('\n', stderr);
1322 goto_fixup_chain = NULL;
1325 /* Generate RTL for an asm statement (explicit assembler code).
1326 BODY is a STRING_CST node containing the assembler code text,
1327 or an ADDR_EXPR containing a STRING_CST. */
1333 if (output_bytecode)
1335 error ("`asm' is invalid when generating bytecode");
1339 if (TREE_CODE (body) == ADDR_EXPR)
1340 body = TREE_OPERAND (body, 0);
1342 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1343 TREE_STRING_POINTER (body)));
1347 /* Generate RTL for an asm statement with arguments.
1348 STRING is the instruction template.
1349 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1350 Each output or input has an expression in the TREE_VALUE and
1351 a constraint-string in the TREE_PURPOSE.
1352 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1353 that is clobbered by this insn.
1355 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1356 Some elements of OUTPUTS may be replaced with trees representing temporary
1357 values. The caller should copy those temporary values to the originally
1360 VOL nonzero means the insn is volatile; don't optimize it. */
1363 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1364 tree string, outputs, inputs, clobbers;
1369 rtvec argvec, constraints;
1371 int ninputs = list_length (inputs);
1372 int noutputs = list_length (outputs);
1376 /* Vector of RTX's of evaluated output operands. */
1377 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1378 /* The insn we have emitted. */
1381 if (output_bytecode)
1383 error ("`asm' is invalid when generating bytecode");
1387 /* Count the number of meaningful clobbered registers, ignoring what
1388 we would ignore later. */
1390 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1392 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1393 i = decode_reg_name (regname);
1394 if (i >= 0 || i == -4)
1397 error ("unknown register name `%s' in `asm'", regname);
1402 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1404 tree val = TREE_VALUE (tail);
1405 tree type = TREE_TYPE (val);
1410 /* If there's an erroneous arg, emit no insn. */
1411 if (TREE_TYPE (val) == error_mark_node)
1414 /* Make sure constraint has `=' and does not have `+'. */
1417 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1419 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1421 error ("output operand constraint contains `+'");
1424 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=')
1429 error ("output operand constraint lacks `='");
1433 /* If an output operand is not a decl or indirect ref,
1434 make a temporary to act as an intermediate. Make the asm insn
1435 write into that, then our caller will copy it to the real output
1436 operand. Likewise for promoted variables. */
1438 if (TREE_CODE (val) == INDIRECT_REF
1439 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1440 && ! (GET_CODE (DECL_RTL (val)) == REG
1441 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
1442 output_rtx[i] = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1445 if (TYPE_MODE (type) == BLKmode)
1447 output_rtx[i] = assign_stack_temp (BLKmode,
1448 int_size_in_bytes (type), 0);
1449 MEM_IN_STRUCT_P (output_rtx[i]) = AGGREGATE_TYPE_P (type);
1452 output_rtx[i] = gen_reg_rtx (TYPE_MODE (type));
1454 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1458 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1460 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1464 /* Make vectors for the expression-rtx and constraint strings. */
1466 argvec = rtvec_alloc (ninputs);
1467 constraints = rtvec_alloc (ninputs);
1469 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1470 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1472 MEM_VOLATILE_P (body) = vol;
1474 /* Eval the inputs and put them into ARGVEC.
1475 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1478 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1482 /* If there's an erroneous arg, emit no insn,
1483 because the ASM_INPUT would get VOIDmode
1484 and that could cause a crash in reload. */
1485 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1487 if (TREE_PURPOSE (tail) == NULL_TREE)
1489 error ("hard register `%s' listed as input operand to `asm'",
1490 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1494 /* Make sure constraint has neither `=' nor `+'. */
1496 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1497 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '='
1498 || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1500 error ("input operand constraint contains `%c'",
1501 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1505 XVECEXP (body, 3, i) /* argvec */
1506 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1507 if (CONSTANT_P (XVECEXP (body, 3, i))
1508 && ! general_operand (XVECEXP (body, 3, i),
1509 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1510 XVECEXP (body, 3, i)
1511 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1512 XVECEXP (body, 3, i));
1513 XVECEXP (body, 4, i) /* constraints */
1514 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1515 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1519 /* Protect all the operands from the queue,
1520 now that they have all been evaluated. */
1522 for (i = 0; i < ninputs; i++)
1523 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1525 for (i = 0; i < noutputs; i++)
1526 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1528 /* Now, for each output, construct an rtx
1529 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1530 ARGVEC CONSTRAINTS))
1531 If there is more than one, put them inside a PARALLEL. */
1533 if (noutputs == 1 && nclobbers == 0)
1535 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1536 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1538 else if (noutputs == 0 && nclobbers == 0)
1540 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1541 insn = emit_insn (body);
1547 if (num == 0) num = 1;
1548 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1550 /* For each output operand, store a SET. */
1552 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1554 XVECEXP (body, 0, i)
1555 = gen_rtx (SET, VOIDmode,
1557 gen_rtx (ASM_OPERANDS, VOIDmode,
1558 TREE_STRING_POINTER (string),
1559 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1560 i, argvec, constraints,
1562 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1565 /* If there are no outputs (but there are some clobbers)
1566 store the bare ASM_OPERANDS into the PARALLEL. */
1569 XVECEXP (body, 0, i++) = obody;
1571 /* Store (clobber REG) for each clobbered register specified. */
1573 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1575 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1576 int j = decode_reg_name (regname);
1580 if (j == -3) /* `cc', which is not a register */
1583 if (j == -4) /* `memory', don't cache memory across asm */
1585 XVECEXP (body, 0, i++)
1586 = gen_rtx (CLOBBER, VOIDmode,
1587 gen_rtx (MEM, BLKmode,
1588 gen_rtx (SCRATCH, VOIDmode, 0)));
1592 /* Ignore unknown register, error already signalled. */
1595 /* Use QImode since that's guaranteed to clobber just one reg. */
1596 XVECEXP (body, 0, i++)
1597 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1600 insn = emit_insn (body);
1606 /* Generate RTL to evaluate the expression EXP
1607 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1610 expand_expr_stmt (exp)
1613 if (output_bytecode)
1615 int org_stack_depth = stack_depth;
1617 bc_expand_expr (exp);
1619 /* Restore stack depth */
1620 if (stack_depth < org_stack_depth)
1623 bc_emit_instruction (drop);
1625 last_expr_type = TREE_TYPE (exp);
1629 /* If -W, warn about statements with no side effects,
1630 except for an explicit cast to void (e.g. for assert()), and
1631 except inside a ({...}) where they may be useful. */
1632 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1634 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1635 && !(TREE_CODE (exp) == CONVERT_EXPR
1636 && TREE_TYPE (exp) == void_type_node))
1637 warning_with_file_and_line (emit_filename, emit_lineno,
1638 "statement with no effect");
1639 else if (warn_unused)
1640 warn_if_unused_value (exp);
1643 /* If EXP is of function type and we are expanding statements for
1644 value, convert it to pointer-to-function. */
1645 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1646 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1648 last_expr_type = TREE_TYPE (exp);
1649 if (! flag_syntax_only)
1650 last_expr_value = expand_expr (exp,
1651 (expr_stmts_for_value
1652 ? NULL_RTX : const0_rtx),
1655 /* If all we do is reference a volatile value in memory,
1656 copy it to a register to be sure it is actually touched. */
1657 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1658 && TREE_THIS_VOLATILE (exp))
1660 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1662 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1663 copy_to_reg (last_expr_value);
1666 rtx lab = gen_label_rtx ();
1668 /* Compare the value with itself to reference it. */
1669 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1670 expand_expr (TYPE_SIZE (last_expr_type),
1671 NULL_RTX, VOIDmode, 0),
1673 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1674 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1679 /* If this expression is part of a ({...}) and is in memory, we may have
1680 to preserve temporaries. */
1681 preserve_temp_slots (last_expr_value);
1683 /* Free any temporaries used to evaluate this expression. Any temporary
1684 used as a result of this expression will already have been preserved
1691 /* Warn if EXP contains any computations whose results are not used.
1692 Return 1 if a warning is printed; 0 otherwise. */
1695 warn_if_unused_value (exp)
1698 if (TREE_USED (exp))
1701 switch (TREE_CODE (exp))
1703 case PREINCREMENT_EXPR:
1704 case POSTINCREMENT_EXPR:
1705 case PREDECREMENT_EXPR:
1706 case POSTDECREMENT_EXPR:
1711 case METHOD_CALL_EXPR:
1713 case WITH_CLEANUP_EXPR:
1715 /* We don't warn about COND_EXPR because it may be a useful
1716 construct if either arm contains a side effect. */
1721 /* For a binding, warn if no side effect within it. */
1722 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1725 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1727 case TRUTH_ORIF_EXPR:
1728 case TRUTH_ANDIF_EXPR:
1729 /* In && or ||, warn if 2nd operand has no side effect. */
1730 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1733 if (TREE_NO_UNUSED_WARNING (exp))
1735 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1737 /* Let people do `(foo (), 0)' without a warning. */
1738 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1740 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1744 case NON_LVALUE_EXPR:
1745 /* Don't warn about values cast to void. */
1746 if (TREE_TYPE (exp) == void_type_node)
1748 /* Don't warn about conversions not explicit in the user's program. */
1749 if (TREE_NO_UNUSED_WARNING (exp))
1751 /* Assignment to a cast usually results in a cast of a modify.
1752 Don't complain about that. There can be an arbitrary number of
1753 casts before the modify, so we must loop until we find the first
1754 non-cast expression and then test to see if that is a modify. */
1756 tree tem = TREE_OPERAND (exp, 0);
1758 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1759 tem = TREE_OPERAND (tem, 0);
1761 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1762 || TREE_CODE (tem) == CALL_EXPR)
1768 /* Don't warn about automatic dereferencing of references, since
1769 the user cannot control it. */
1770 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1771 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1772 /* ... fall through ... */
1775 /* Referencing a volatile value is a side effect, so don't warn. */
1776 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1777 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1778 && TREE_THIS_VOLATILE (exp))
1781 warning_with_file_and_line (emit_filename, emit_lineno,
1782 "value computed is not used");
1787 /* Clear out the memory of the last expression evaluated. */
1795 /* Begin a statement which will return a value.
1796 Return the RTL_EXPR for this statement expr.
1797 The caller must save that value and pass it to expand_end_stmt_expr. */
1800 expand_start_stmt_expr ()
1805 /* When generating bytecode just note down the stack depth */
1806 if (output_bytecode)
1807 return (build_int_2 (stack_depth, 0));
1809 /* Make the RTL_EXPR node temporary, not momentary,
1810 so that rtl_expr_chain doesn't become garbage. */
1811 momentary = suspend_momentary ();
1812 t = make_node (RTL_EXPR);
1813 resume_momentary (momentary);
1814 start_sequence_for_rtl_expr (t);
1816 expr_stmts_for_value++;
1820 /* Restore the previous state at the end of a statement that returns a value.
1821 Returns a tree node representing the statement's value and the
1822 insns to compute the value.
1824 The nodes of that expression have been freed by now, so we cannot use them.
1825 But we don't want to do that anyway; the expression has already been
1826 evaluated and now we just want to use the value. So generate a RTL_EXPR
1827 with the proper type and RTL value.
1829 If the last substatement was not an expression,
1830 return something with type `void'. */
1833 expand_end_stmt_expr (t)
1836 if (output_bytecode)
1842 /* At this point, all expressions have been evaluated in order.
1843 However, all expression values have been popped when evaluated,
1844 which means we have to recover the last expression value. This is
1845 the last value removed by means of a `drop' instruction. Instead
1846 of adding code to inhibit dropping the last expression value, it
1847 is here recovered by undoing the `drop'. Since `drop' is
1848 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1851 bc_adjust_stack (-1);
1853 if (!last_expr_type)
1854 last_expr_type = void_type_node;
1856 t = make_node (RTL_EXPR);
1857 TREE_TYPE (t) = last_expr_type;
1858 RTL_EXPR_RTL (t) = NULL;
1859 RTL_EXPR_SEQUENCE (t) = NULL;
1861 /* Don't consider deleting this expr or containing exprs at tree level. */
1862 TREE_THIS_VOLATILE (t) = 1;
1870 if (last_expr_type == 0)
1872 last_expr_type = void_type_node;
1873 last_expr_value = const0_rtx;
1875 else if (last_expr_value == 0)
1876 /* There are some cases where this can happen, such as when the
1877 statement is void type. */
1878 last_expr_value = const0_rtx;
1879 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1880 /* Remove any possible QUEUED. */
1881 last_expr_value = protect_from_queue (last_expr_value, 0);
1885 TREE_TYPE (t) = last_expr_type;
1886 RTL_EXPR_RTL (t) = last_expr_value;
1887 RTL_EXPR_SEQUENCE (t) = get_insns ();
1889 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1893 /* Don't consider deleting this expr or containing exprs at tree level. */
1894 TREE_SIDE_EFFECTS (t) = 1;
1895 /* Propagate volatility of the actual RTL expr. */
1896 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1899 expr_stmts_for_value--;
1904 /* Generate RTL for the start of an if-then. COND is the expression
1905 whose truth should be tested.
1907 If EXITFLAG is nonzero, this conditional is visible to
1908 `exit_something'. */
1911 expand_start_cond (cond, exitflag)
1915 struct nesting *thiscond = ALLOC_NESTING ();
1917 /* Make an entry on cond_stack for the cond we are entering. */
1919 thiscond->next = cond_stack;
1920 thiscond->all = nesting_stack;
1921 thiscond->depth = ++nesting_depth;
1922 thiscond->data.cond.next_label = gen_label_rtx ();
1923 /* Before we encounter an `else', we don't need a separate exit label
1924 unless there are supposed to be exit statements
1925 to exit this conditional. */
1926 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1927 thiscond->data.cond.endif_label = thiscond->exit_label;
1928 cond_stack = thiscond;
1929 nesting_stack = thiscond;
1931 if (output_bytecode)
1932 bc_expand_start_cond (cond, exitflag);
1934 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1937 /* Generate RTL between then-clause and the elseif-clause
1938 of an if-then-elseif-.... */
1941 expand_start_elseif (cond)
1944 if (cond_stack->data.cond.endif_label == 0)
1945 cond_stack->data.cond.endif_label = gen_label_rtx ();
1946 emit_jump (cond_stack->data.cond.endif_label);
1947 emit_label (cond_stack->data.cond.next_label);
1948 cond_stack->data.cond.next_label = gen_label_rtx ();
1949 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1952 /* Generate RTL between the then-clause and the else-clause
1953 of an if-then-else. */
1956 expand_start_else ()
1958 if (cond_stack->data.cond.endif_label == 0)
1959 cond_stack->data.cond.endif_label = gen_label_rtx ();
1961 if (output_bytecode)
1963 bc_expand_start_else ();
1967 emit_jump (cond_stack->data.cond.endif_label);
1968 emit_label (cond_stack->data.cond.next_label);
1969 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
1972 /* After calling expand_start_else, turn this "else" into an "else if"
1973 by providing another condition. */
1976 expand_elseif (cond)
1979 cond_stack->data.cond.next_label = gen_label_rtx ();
1980 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1983 /* Generate RTL for the end of an if-then.
1984 Pop the record for it off of cond_stack. */
1989 struct nesting *thiscond = cond_stack;
1991 if (output_bytecode)
1992 bc_expand_end_cond ();
1995 do_pending_stack_adjust ();
1996 if (thiscond->data.cond.next_label)
1997 emit_label (thiscond->data.cond.next_label);
1998 if (thiscond->data.cond.endif_label)
1999 emit_label (thiscond->data.cond.endif_label);
2002 POPSTACK (cond_stack);
2007 /* Generate code for the start of an if-then. COND is the expression
2008 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2009 is to be visible to exit_something. It is assumed that the caller
2010 has pushed the previous context on the cond stack. */
2013 bc_expand_start_cond (cond, exitflag)
2017 struct nesting *thiscond = cond_stack;
2019 thiscond->data.case_stmt.nominal_type = cond;
2021 thiscond->exit_label = gen_label_rtx ();
2022 bc_expand_expr (cond);
2023 bc_emit_bytecode (xjumpifnot);
2024 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2026 #ifdef DEBUG_PRINT_CODE
2027 fputc ('\n', stderr);
2031 /* Generate the label for the end of an if with
2035 bc_expand_end_cond ()
2037 struct nesting *thiscond = cond_stack;
2039 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2042 /* Generate code for the start of the else- clause of
2046 bc_expand_start_else ()
2048 struct nesting *thiscond = cond_stack;
2050 thiscond->data.cond.endif_label = thiscond->exit_label;
2051 thiscond->exit_label = gen_label_rtx ();
2052 bc_emit_bytecode (jump);
2053 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2055 #ifdef DEBUG_PRINT_CODE
2056 fputc ('\n', stderr);
2059 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2062 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2063 loop should be exited by `exit_something'. This is a loop for which
2064 `expand_continue' will jump to the top of the loop.
2066 Make an entry on loop_stack to record the labels associated with
2070 expand_start_loop (exit_flag)
2073 register struct nesting *thisloop = ALLOC_NESTING ();
2075 /* Make an entry on loop_stack for the loop we are entering. */
2077 thisloop->next = loop_stack;
2078 thisloop->all = nesting_stack;
2079 thisloop->depth = ++nesting_depth;
2080 thisloop->data.loop.start_label = gen_label_rtx ();
2081 thisloop->data.loop.end_label = gen_label_rtx ();
2082 thisloop->data.loop.alt_end_label = 0;
2083 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2084 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2085 loop_stack = thisloop;
2086 nesting_stack = thisloop;
2088 if (output_bytecode)
2090 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2094 do_pending_stack_adjust ();
2096 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2097 emit_label (thisloop->data.loop.start_label);
2102 /* Like expand_start_loop but for a loop where the continuation point
2103 (for expand_continue_loop) will be specified explicitly. */
2106 expand_start_loop_continue_elsewhere (exit_flag)
2109 struct nesting *thisloop = expand_start_loop (exit_flag);
2110 loop_stack->data.loop.continue_label = gen_label_rtx ();
2114 /* Specify the continuation point for a loop started with
2115 expand_start_loop_continue_elsewhere.
2116 Use this at the point in the code to which a continue statement
2120 expand_loop_continue_here ()
2122 if (output_bytecode)
2124 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2127 do_pending_stack_adjust ();
2128 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2129 emit_label (loop_stack->data.loop.continue_label);
2135 bc_expand_end_loop ()
2137 struct nesting *thisloop = loop_stack;
2139 bc_emit_bytecode (jump);
2140 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2142 #ifdef DEBUG_PRINT_CODE
2143 fputc ('\n', stderr);
2146 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2147 POPSTACK (loop_stack);
2152 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2153 Pop the block off of loop_stack. */
2159 register rtx start_label;
2160 rtx last_test_insn = 0;
2163 if (output_bytecode)
2165 bc_expand_end_loop ();
2169 insn = get_last_insn ();
2170 start_label = loop_stack->data.loop.start_label;
2172 /* Mark the continue-point at the top of the loop if none elsewhere. */
2173 if (start_label == loop_stack->data.loop.continue_label)
2174 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2176 do_pending_stack_adjust ();
2178 /* If optimizing, perhaps reorder the loop. If the loop
2179 starts with a conditional exit, roll that to the end
2180 where it will optimize together with the jump back.
2182 We look for the last conditional branch to the exit that we encounter
2183 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2184 branch to the exit first, use it.
2186 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2187 because moving them is not valid. */
2191 ! (GET_CODE (insn) == JUMP_INSN
2192 && GET_CODE (PATTERN (insn)) == SET
2193 && SET_DEST (PATTERN (insn)) == pc_rtx
2194 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2196 /* Scan insns from the top of the loop looking for a qualified
2197 conditional exit. */
2198 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2199 insn = NEXT_INSN (insn))
2201 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2204 if (GET_CODE (insn) == NOTE
2205 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2206 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2209 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2212 if (last_test_insn && num_insns > 30)
2215 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2216 && SET_DEST (PATTERN (insn)) == pc_rtx
2217 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2218 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2219 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2220 == loop_stack->data.loop.end_label)
2221 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2222 == loop_stack->data.loop.alt_end_label)))
2223 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2224 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2225 == loop_stack->data.loop.end_label)
2226 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2227 == loop_stack->data.loop.alt_end_label)))))
2228 last_test_insn = insn;
2230 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2231 && GET_CODE (PATTERN (insn)) == SET
2232 && SET_DEST (PATTERN (insn)) == pc_rtx
2233 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2234 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2235 == loop_stack->data.loop.end_label)
2236 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2237 == loop_stack->data.loop.alt_end_label)))
2238 /* Include BARRIER. */
2239 last_test_insn = NEXT_INSN (insn);
2242 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2244 /* We found one. Move everything from there up
2245 to the end of the loop, and add a jump into the loop
2246 to jump to there. */
2247 register rtx newstart_label = gen_label_rtx ();
2248 register rtx start_move = start_label;
2250 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2251 then we want to move this note also. */
2252 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2253 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2254 == NOTE_INSN_LOOP_CONT))
2255 start_move = PREV_INSN (start_move);
2257 emit_label_after (newstart_label, PREV_INSN (start_move));
2258 reorder_insns (start_move, last_test_insn, get_last_insn ());
2259 emit_jump_insn_after (gen_jump (start_label),
2260 PREV_INSN (newstart_label));
2261 emit_barrier_after (PREV_INSN (newstart_label));
2262 start_label = newstart_label;
2266 emit_jump (start_label);
2267 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2268 emit_label (loop_stack->data.loop.end_label);
2270 POPSTACK (loop_stack);
2275 /* Generate a jump to the current loop's continue-point.
2276 This is usually the top of the loop, but may be specified
2277 explicitly elsewhere. If not currently inside a loop,
2278 return 0 and do nothing; caller will print an error message. */
2281 expand_continue_loop (whichloop)
2282 struct nesting *whichloop;
2286 whichloop = loop_stack;
2289 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2294 /* Generate a jump to exit the current loop. If not currently inside a loop,
2295 return 0 and do nothing; caller will print an error message. */
2298 expand_exit_loop (whichloop)
2299 struct nesting *whichloop;
2303 whichloop = loop_stack;
2306 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2310 /* Generate a conditional jump to exit the current loop if COND
2311 evaluates to zero. If not currently inside a loop,
2312 return 0 and do nothing; caller will print an error message. */
2315 expand_exit_loop_if_false (whichloop, cond)
2316 struct nesting *whichloop;
2321 whichloop = loop_stack;
2324 if (output_bytecode)
2326 bc_expand_expr (cond);
2327 bc_expand_goto_internal (xjumpifnot,
2328 BYTECODE_BC_LABEL (whichloop->exit_label),
2333 /* In order to handle fixups, we actually create a conditional jump
2334 around a unconditional branch to exit the loop. If fixups are
2335 necessary, they go before the unconditional branch. */
2337 rtx label = gen_label_rtx ();
2340 do_jump (cond, NULL_RTX, label);
2341 last_insn = get_last_insn ();
2342 if (GET_CODE (last_insn) == CODE_LABEL)
2343 whichloop->data.loop.alt_end_label = last_insn;
2344 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2352 /* Return non-zero if we should preserve sub-expressions as separate
2353 pseudos. We never do so if we aren't optimizing. We always do so
2354 if -fexpensive-optimizations.
2356 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2357 the loop may still be a small one. */
2360 preserve_subexpressions_p ()
2364 if (flag_expensive_optimizations)
2367 if (optimize == 0 || loop_stack == 0)
2370 insn = get_last_insn_anywhere ();
2373 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2374 < n_non_fixed_regs * 3));
2378 /* Generate a jump to exit the current loop, conditional, binding contour
2379 or case statement. Not all such constructs are visible to this function,
2380 only those started with EXIT_FLAG nonzero. Individual languages use
2381 the EXIT_FLAG parameter to control which kinds of constructs you can
2384 If not currently inside anything that can be exited,
2385 return 0 and do nothing; caller will print an error message. */
2388 expand_exit_something ()
2392 for (n = nesting_stack; n; n = n->all)
2393 if (n->exit_label != 0)
2395 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2402 /* Generate RTL to return from the current function, with no value.
2403 (That is, we do not do anything about returning any value.) */
2406 expand_null_return ()
2408 struct nesting *block = block_stack;
2411 if (output_bytecode)
2413 bc_emit_instruction (ret);
2417 /* Does any pending block have cleanups? */
2419 while (block && block->data.block.cleanups == 0)
2420 block = block->next;
2422 /* If yes, use a goto to return, since that runs cleanups. */
2424 expand_null_return_1 (last_insn, block != 0);
2427 /* Generate RTL to return from the current function, with value VAL. */
2430 expand_value_return (val)
2433 struct nesting *block = block_stack;
2434 rtx last_insn = get_last_insn ();
2435 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2437 /* Copy the value to the return location
2438 unless it's already there. */
2440 if (return_reg != val)
2442 #ifdef PROMOTE_FUNCTION_RETURN
2443 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2444 int unsignedp = TREE_UNSIGNED (type);
2445 enum machine_mode mode
2446 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2449 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2450 convert_move (return_reg, val, unsignedp);
2453 emit_move_insn (return_reg, val);
2455 if (GET_CODE (return_reg) == REG
2456 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2457 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2459 /* Does any pending block have cleanups? */
2461 while (block && block->data.block.cleanups == 0)
2462 block = block->next;
2464 /* If yes, use a goto to return, since that runs cleanups.
2465 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2467 expand_null_return_1 (last_insn, block != 0);
2470 /* Output a return with no value. If LAST_INSN is nonzero,
2471 pretend that the return takes place after LAST_INSN.
2472 If USE_GOTO is nonzero then don't use a return instruction;
2473 go to the return label instead. This causes any cleanups
2474 of pending blocks to be executed normally. */
2477 expand_null_return_1 (last_insn, use_goto)
2481 rtx end_label = cleanup_label ? cleanup_label : return_label;
2483 clear_pending_stack_adjust ();
2484 do_pending_stack_adjust ();
2487 /* PCC-struct return always uses an epilogue. */
2488 if (current_function_returns_pcc_struct || use_goto)
2491 end_label = return_label = gen_label_rtx ();
2492 expand_goto_internal (NULL_TREE, end_label, last_insn);
2496 /* Otherwise output a simple return-insn if one is available,
2497 unless it won't do the job. */
2499 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2501 emit_jump_insn (gen_return ());
2507 /* Otherwise jump to the epilogue. */
2508 expand_goto_internal (NULL_TREE, end_label, last_insn);
2511 /* Generate RTL to evaluate the expression RETVAL and return it
2512 from the current function. */
2515 expand_return (retval)
2518 /* If there are any cleanups to be performed, then they will
2519 be inserted following LAST_INSN. It is desirable
2520 that the last_insn, for such purposes, should be the
2521 last insn before computing the return value. Otherwise, cleanups
2522 which call functions can clobber the return value. */
2523 /* ??? rms: I think that is erroneous, because in C++ it would
2524 run destructors on variables that might be used in the subsequent
2525 computation of the return value. */
2527 register rtx val = 0;
2531 struct nesting *block;
2533 /* Bytecode returns are quite simple, just leave the result on the
2534 arithmetic stack. */
2535 if (output_bytecode)
2537 bc_expand_expr (retval);
2538 bc_emit_instruction (ret);
2542 /* If function wants no value, give it none. */
2543 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2545 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2547 expand_null_return ();
2551 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2552 /* This is not sufficient. We also need to watch for cleanups of the
2553 expression we are about to expand. Unfortunately, we cannot know
2554 if it has cleanups until we expand it, and we want to change how we
2555 expand it depending upon if we need cleanups. We can't win. */
2557 cleanups = any_pending_cleanups (1);
2562 if (TREE_CODE (retval) == RESULT_DECL)
2563 retval_rhs = retval;
2564 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2565 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2566 retval_rhs = TREE_OPERAND (retval, 1);
2567 else if (TREE_TYPE (retval) == void_type_node)
2568 /* Recognize tail-recursive call to void function. */
2569 retval_rhs = retval;
2571 retval_rhs = NULL_TREE;
2573 /* Only use `last_insn' if there are cleanups which must be run. */
2574 if (cleanups || cleanup_label != 0)
2575 last_insn = get_last_insn ();
2577 /* Distribute return down conditional expr if either of the sides
2578 may involve tail recursion (see test below). This enhances the number
2579 of tail recursions we see. Don't do this always since it can produce
2580 sub-optimal code in some cases and we distribute assignments into
2581 conditional expressions when it would help. */
2583 if (optimize && retval_rhs != 0
2584 && frame_offset == 0
2585 && TREE_CODE (retval_rhs) == COND_EXPR
2586 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2587 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2589 rtx label = gen_label_rtx ();
2592 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2593 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2594 DECL_RESULT (current_function_decl),
2595 TREE_OPERAND (retval_rhs, 1));
2596 TREE_SIDE_EFFECTS (expr) = 1;
2597 expand_return (expr);
2600 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2601 DECL_RESULT (current_function_decl),
2602 TREE_OPERAND (retval_rhs, 2));
2603 TREE_SIDE_EFFECTS (expr) = 1;
2604 expand_return (expr);
2608 /* For tail-recursive call to current function,
2609 just jump back to the beginning.
2610 It's unsafe if any auto variable in this function
2611 has its address taken; for simplicity,
2612 require stack frame to be empty. */
2613 if (optimize && retval_rhs != 0
2614 && frame_offset == 0
2615 && TREE_CODE (retval_rhs) == CALL_EXPR
2616 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2617 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2618 /* Finish checking validity, and if valid emit code
2619 to set the argument variables for the new call. */
2620 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2621 DECL_ARGUMENTS (current_function_decl)))
2623 if (tail_recursion_label == 0)
2625 tail_recursion_label = gen_label_rtx ();
2626 emit_label_after (tail_recursion_label,
2627 tail_recursion_reentry);
2630 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2635 /* This optimization is safe if there are local cleanups
2636 because expand_null_return takes care of them.
2637 ??? I think it should also be safe when there is a cleanup label,
2638 because expand_null_return takes care of them, too.
2639 Any reason why not? */
2640 if (HAVE_return && cleanup_label == 0
2641 && ! current_function_returns_pcc_struct
2642 && BRANCH_COST <= 1)
2644 /* If this is return x == y; then generate
2645 if (x == y) return 1; else return 0;
2646 if we can do it with explicit return insns and
2647 branches are cheap. */
2649 switch (TREE_CODE (retval_rhs))
2657 case TRUTH_ANDIF_EXPR:
2658 case TRUTH_ORIF_EXPR:
2659 case TRUTH_AND_EXPR:
2661 case TRUTH_NOT_EXPR:
2662 case TRUTH_XOR_EXPR:
2663 op0 = gen_label_rtx ();
2664 jumpifnot (retval_rhs, op0);
2665 expand_value_return (const1_rtx);
2667 expand_value_return (const0_rtx);
2671 #endif /* HAVE_return */
2673 /* If the result is an aggregate that is being returned in one (or more)
2674 registers, load the registers here. The compiler currently can't handle
2675 copying a BLKmode value into registers. We could put this code in a
2676 more general area (for use by everyone instead of just function
2677 call/return), but until this feature is generally usable it is kept here
2678 (and in expand_call). */
2681 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2682 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2685 int big_endian_correction = 0;
2686 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2687 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2688 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2689 rtx result_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2690 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2691 enum machine_mode tmpmode;
2693 /* Structures smaller than a word are aligned to the least significant
2694 byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we
2695 must skip the empty high order bytes when calculating the bit
2697 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
2698 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
2700 for (i = 0; i < n_regs; i++)
2702 rtx reg = gen_reg_rtx (word_mode);
2703 rtx word = operand_subword_force (result_val, i, BLKmode);
2704 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2707 result_pseudos[i] = reg;
2709 /* Clobber REG and move each partword into it. Ensure we don't
2710 go past the end of the structure. Note that the loop below
2711 works because we've already verified that padding and
2712 endianness are compatable. */
2713 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
2716 bitpos < BITS_PER_WORD && bytes > 0;
2717 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
2719 int xbitpos = bitpos + big_endian_correction;
2721 store_bit_field (reg, bitsize, xbitpos, word_mode,
2722 extract_bit_field (word, bitsize, bitpos, 1,
2723 NULL_RTX, word_mode,
2725 bitsize / BITS_PER_UNIT,
2727 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2731 /* Now that the value is in pseudos, copy it to the result reg(s). */
2734 for (i = 0; i < n_regs; i++)
2735 emit_move_insn (gen_rtx (REG, word_mode, REGNO (result_reg) + i),
2738 /* Find the smallest integer mode large enough to hold the
2739 entire structure and use that mode instead of BLKmode
2740 on the USE insn for the return register. */
2741 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2742 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2743 tmpmode != MAX_MACHINE_MODE;
2744 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2746 /* Have we found a large enough mode? */
2747 if (GET_MODE_SIZE (tmpmode) >= bytes)
2751 /* No suitable mode found. */
2752 if (tmpmode == MAX_MACHINE_MODE)
2755 PUT_MODE (result_reg, tmpmode);
2757 expand_value_return (result_reg);
2761 && TREE_TYPE (retval_rhs) != void_type_node
2762 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2764 /* Calculate the return value into a pseudo reg. */
2765 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2767 /* All temporaries have now been used. */
2769 /* Return the calculated value, doing cleanups first. */
2770 expand_value_return (val);
2774 /* No cleanups or no hard reg used;
2775 calculate value into hard return reg. */
2776 expand_expr (retval, const0_rtx, VOIDmode, 0);
2779 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2783 /* Return 1 if the end of the generated RTX is not a barrier.
2784 This means code already compiled can drop through. */
2787 drop_through_at_end_p ()
2789 rtx insn = get_last_insn ();
2790 while (insn && GET_CODE (insn) == NOTE)
2791 insn = PREV_INSN (insn);
2792 return insn && GET_CODE (insn) != BARRIER;
2795 /* Emit code to alter this function's formal parms for a tail-recursive call.
2796 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2797 FORMALS is the chain of decls of formals.
2798 Return 1 if this can be done;
2799 otherwise return 0 and do not emit any code. */
2802 tail_recursion_args (actuals, formals)
2803 tree actuals, formals;
2805 register tree a = actuals, f = formals;
2807 register rtx *argvec;
2809 /* Check that number and types of actuals are compatible
2810 with the formals. This is not always true in valid C code.
2811 Also check that no formal needs to be addressable
2812 and that all formals are scalars. */
2814 /* Also count the args. */
2816 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2818 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2820 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2823 if (a != 0 || f != 0)
2826 /* Compute all the actuals. */
2828 argvec = (rtx *) alloca (i * sizeof (rtx));
2830 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2831 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2833 /* Find which actual values refer to current values of previous formals.
2834 Copy each of them now, before any formal is changed. */
2836 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2840 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2841 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2842 { copy = 1; break; }
2844 argvec[i] = copy_to_reg (argvec[i]);
2847 /* Store the values of the actuals into the formals. */
2849 for (f = formals, a = actuals, i = 0; f;
2850 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2852 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2853 emit_move_insn (DECL_RTL (f), argvec[i]);
2855 convert_move (DECL_RTL (f), argvec[i],
2856 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2863 /* Generate the RTL code for entering a binding contour.
2864 The variables are declared one by one, by calls to `expand_decl'.
2866 EXIT_FLAG is nonzero if this construct should be visible to
2867 `exit_something'. */
2870 expand_start_bindings (exit_flag)
2873 struct nesting *thisblock = ALLOC_NESTING ();
2874 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2876 /* Make an entry on block_stack for the block we are entering. */
2878 thisblock->next = block_stack;
2879 thisblock->all = nesting_stack;
2880 thisblock->depth = ++nesting_depth;
2881 thisblock->data.block.stack_level = 0;
2882 thisblock->data.block.cleanups = 0;
2883 thisblock->data.block.function_call_count = 0;
2887 if (block_stack->data.block.cleanups == NULL_TREE
2888 && (block_stack->data.block.outer_cleanups == NULL_TREE
2889 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2890 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2892 thisblock->data.block.outer_cleanups
2893 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2894 block_stack->data.block.outer_cleanups);
2897 thisblock->data.block.outer_cleanups = 0;
2901 && !(block_stack->data.block.cleanups == NULL_TREE
2902 && block_stack->data.block.outer_cleanups == NULL_TREE))
2903 thisblock->data.block.outer_cleanups
2904 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2905 block_stack->data.block.outer_cleanups);
2907 thisblock->data.block.outer_cleanups = 0;
2909 thisblock->data.block.label_chain = 0;
2910 thisblock->data.block.innermost_stack_block = stack_block_stack;
2911 thisblock->data.block.first_insn = note;
2912 thisblock->data.block.block_start_count = ++block_start_count;
2913 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2914 block_stack = thisblock;
2915 nesting_stack = thisblock;
2917 if (!output_bytecode)
2919 /* Make a new level for allocating stack slots. */
2924 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2925 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2929 remember_end_note (block)
2930 register tree block;
2932 BLOCK_END_NOTE (block) = last_block_end_note;
2933 last_block_end_note = NULL_RTX;
2936 /* Generate RTL code to terminate a binding contour.
2937 VARS is the chain of VAR_DECL nodes
2938 for the variables bound in this contour.
2939 MARK_ENDS is nonzero if we should put a note at the beginning
2940 and end of this binding contour.
2942 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2943 (That is true automatically if the contour has a saved stack level.) */
2946 expand_end_bindings (vars, mark_ends, dont_jump_in)
2951 register struct nesting *thisblock = block_stack;
2954 if (output_bytecode)
2956 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
2961 for (decl = vars; decl; decl = TREE_CHAIN (decl))
2962 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
2963 && ! DECL_IN_SYSTEM_HEADER (decl))
2964 warning_with_decl (decl, "unused variable `%s'");
2966 if (thisblock->exit_label)
2968 do_pending_stack_adjust ();
2969 emit_label (thisblock->exit_label);
2972 /* If necessary, make a handler for nonlocal gotos taking
2973 place in the function calls in this block. */
2974 if (function_call_count != thisblock->data.block.function_call_count
2976 /* Make handler for outermost block
2977 if there were any nonlocal gotos to this function. */
2978 && (thisblock->next == 0 ? current_function_has_nonlocal_label
2979 /* Make handler for inner block if it has something
2980 special to do when you jump out of it. */
2981 : (thisblock->data.block.cleanups != 0
2982 || thisblock->data.block.stack_level != 0)))
2985 rtx afterward = gen_label_rtx ();
2986 rtx handler_label = gen_label_rtx ();
2987 rtx save_receiver = gen_reg_rtx (Pmode);
2990 /* Don't let jump_optimize delete the handler. */
2991 LABEL_PRESERVE_P (handler_label) = 1;
2993 /* Record the handler address in the stack slot for that purpose,
2994 during this block, saving and restoring the outer value. */
2995 if (thisblock->next != 0)
2997 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3000 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3001 insns = get_insns ();
3003 emit_insns_before (insns, thisblock->data.block.first_insn);
3007 emit_move_insn (nonlocal_goto_handler_slot,
3008 gen_rtx (LABEL_REF, Pmode, handler_label));
3009 insns = get_insns ();
3011 emit_insns_before (insns, thisblock->data.block.first_insn);
3013 /* Jump around the handler; it runs only when specially invoked. */
3014 emit_jump (afterward);
3015 emit_label (handler_label);
3017 #ifdef HAVE_nonlocal_goto
3018 if (! HAVE_nonlocal_goto)
3020 /* First adjust our frame pointer to its actual value. It was
3021 previously set to the start of the virtual area corresponding to
3022 the stacked variables when we branched here and now needs to be
3023 adjusted to the actual hardware fp value.
3025 Assignments are to virtual registers are converted by
3026 instantiate_virtual_regs into the corresponding assignment
3027 to the underlying register (fp in this case) that makes
3028 the original assignment true.
3029 So the following insn will actually be
3030 decrementing fp by STARTING_FRAME_OFFSET. */
3031 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3033 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3034 if (fixed_regs[ARG_POINTER_REGNUM])
3036 #ifdef ELIMINABLE_REGS
3037 /* If the argument pointer can be eliminated in favor of the
3038 frame pointer, we don't need to restore it. We assume here
3039 that if such an elimination is present, it can always be used.
3040 This is the case on all known machines; if we don't make this
3041 assumption, we do unnecessary saving on many machines. */
3042 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3045 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3046 if (elim_regs[i].from == ARG_POINTER_REGNUM
3047 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3050 if (i == sizeof elim_regs / sizeof elim_regs [0])
3053 /* Now restore our arg pointer from the address at which it
3054 was saved in our stack frame.
3055 If there hasn't be space allocated for it yet, make
3057 if (arg_pointer_save_area == 0)
3058 arg_pointer_save_area
3059 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3060 emit_move_insn (virtual_incoming_args_rtx,
3061 /* We need a pseudo here, or else
3062 instantiate_virtual_regs_1 complains. */
3063 copy_to_reg (arg_pointer_save_area));
3068 /* The handler expects the desired label address in the static chain
3069 register. It tests the address and does an appropriate jump
3070 to whatever label is desired. */
3071 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3072 /* Skip any labels we shouldn't be able to jump to from here. */
3073 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3075 rtx not_this = gen_label_rtx ();
3076 rtx this = gen_label_rtx ();
3077 do_jump_if_equal (static_chain_rtx,
3078 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3080 emit_jump (not_this);
3082 expand_goto (TREE_VALUE (link));
3083 emit_label (not_this);
3085 /* If label is not recognized, abort. */
3086 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3088 emit_label (afterward);
3091 /* Don't allow jumping into a block that has cleanups or a stack level. */
3093 || thisblock->data.block.stack_level != 0
3094 || thisblock->data.block.cleanups != 0)
3096 struct label_chain *chain;
3098 /* Any labels in this block are no longer valid to go to.
3099 Mark them to cause an error message. */
3100 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3102 DECL_TOO_LATE (chain->label) = 1;
3103 /* If any goto without a fixup came to this label,
3104 that must be an error, because gotos without fixups
3105 come from outside all saved stack-levels and all cleanups. */
3106 if (TREE_ADDRESSABLE (chain->label))
3107 error_with_decl (chain->label,
3108 "label `%s' used before containing binding contour");
3112 /* Restore stack level in effect before the block
3113 (only if variable-size objects allocated). */
3114 /* Perform any cleanups associated with the block. */
3116 if (thisblock->data.block.stack_level != 0
3117 || thisblock->data.block.cleanups != 0)
3119 /* Only clean up here if this point can actually be reached. */
3120 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3122 /* Don't let cleanups affect ({...}) constructs. */
3123 int old_expr_stmts_for_value = expr_stmts_for_value;
3124 rtx old_last_expr_value = last_expr_value;
3125 tree old_last_expr_type = last_expr_type;
3126 expr_stmts_for_value = 0;
3128 /* Do the cleanups. */
3129 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3131 do_pending_stack_adjust ();
3133 expr_stmts_for_value = old_expr_stmts_for_value;
3134 last_expr_value = old_last_expr_value;
3135 last_expr_type = old_last_expr_type;
3137 /* Restore the stack level. */
3139 if (reachable && thisblock->data.block.stack_level != 0)
3141 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3142 thisblock->data.block.stack_level, NULL_RTX);
3143 if (nonlocal_goto_handler_slot != 0)
3144 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3148 /* Any gotos out of this block must also do these things.
3149 Also report any gotos with fixups that came to labels in this
3151 fixup_gotos (thisblock,
3152 thisblock->data.block.stack_level,
3153 thisblock->data.block.cleanups,
3154 thisblock->data.block.first_insn,
3158 /* Mark the beginning and end of the scope if requested.
3159 We do this now, after running cleanups on the variables
3160 just going out of scope, so they are in scope for their cleanups. */
3163 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3165 /* Get rid of the beginning-mark if we don't make an end-mark. */
3166 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3168 /* If doing stupid register allocation, make sure lives of all
3169 register variables declared here extend thru end of scope. */
3172 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3174 rtx rtl = DECL_RTL (decl);
3175 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3179 /* Restore block_stack level for containing block. */
3181 stack_block_stack = thisblock->data.block.innermost_stack_block;
3182 POPSTACK (block_stack);
3184 /* Pop the stack slot nesting and free any slots at this level. */
3189 /* End a binding contour.
3190 VARS is the chain of VAR_DECL nodes for the variables bound
3191 in this contour. MARK_ENDS is nonzer if we should put a note
3192 at the beginning and end of this binding contour.
3193 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3197 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3202 struct nesting *thisbind = nesting_stack;
3206 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3207 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3208 warning_with_decl (decl, "unused variable `%s'");
3210 if (thisbind->exit_label)
3211 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3213 /* Pop block/bindings off stack */
3214 POPSTACK (block_stack);
3217 /* Generate RTL for the automatic variable declaration DECL.
3218 (Other kinds of declarations are simply ignored if seen here.)
3219 CLEANUP is an expression to be executed at exit from this binding contour;
3220 for example, in C++, it might call the destructor for this variable.
3222 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3223 either before or after calling `expand_decl' but before compiling
3224 any subsequent expressions. This is because CLEANUP may be expanded
3225 more than once, on different branches of execution.
3226 For the same reason, CLEANUP may not contain a CALL_EXPR
3227 except as its topmost node--else `preexpand_calls' would get confused.
3229 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3230 that is not associated with any particular variable.
3232 There is no special support here for C++ constructors.
3233 They should be handled by the proper code in DECL_INITIAL. */
3239 struct nesting *thisblock = block_stack;
3242 if (output_bytecode)
3244 bc_expand_decl (decl, 0);
3248 type = TREE_TYPE (decl);
3250 /* Only automatic variables need any expansion done.
3251 Static and external variables, and external functions,
3252 will be handled by `assemble_variable' (called from finish_decl).
3253 TYPE_DECL and CONST_DECL require nothing.
3254 PARM_DECLs are handled in `assign_parms'. */
3256 if (TREE_CODE (decl) != VAR_DECL)
3258 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3261 /* Create the RTL representation for the variable. */
3263 if (type == error_mark_node)
3264 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3265 else if (DECL_SIZE (decl) == 0)
3266 /* Variable with incomplete type. */
3268 if (DECL_INITIAL (decl) == 0)
3269 /* Error message was already done; now avoid a crash. */
3270 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3272 /* An initializer is going to decide the size of this array.
3273 Until we know the size, represent its address with a reg. */
3274 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3275 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3277 else if (DECL_MODE (decl) != BLKmode
3278 /* If -ffloat-store, don't put explicit float vars
3280 && !(flag_float_store
3281 && TREE_CODE (type) == REAL_TYPE)
3282 && ! TREE_THIS_VOLATILE (decl)
3283 && ! TREE_ADDRESSABLE (decl)
3284 && (DECL_REGISTER (decl) || ! obey_regdecls))
3286 /* Automatic variable that can go in a register. */
3287 int unsignedp = TREE_UNSIGNED (type);
3288 enum machine_mode reg_mode
3289 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3291 if (TREE_CODE (type) == COMPLEX_TYPE)
3293 rtx realpart, imagpart;
3294 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3296 /* For a complex type variable, make a CONCAT of two pseudos
3297 so that the real and imaginary parts
3298 can be allocated separately. */
3299 realpart = gen_reg_rtx (partmode);
3300 REG_USERVAR_P (realpart) = 1;
3301 imagpart = gen_reg_rtx (partmode);
3302 REG_USERVAR_P (imagpart) = 1;
3303 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3307 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3308 if (TREE_CODE (type) == POINTER_TYPE)
3309 mark_reg_pointer (DECL_RTL (decl));
3310 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3313 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3315 /* Variable of fixed size that goes on the stack. */
3319 /* If we previously made RTL for this decl, it must be an array
3320 whose size was determined by the initializer.
3321 The old address was a register; set that register now
3322 to the proper address. */
3323 if (DECL_RTL (decl) != 0)
3325 if (GET_CODE (DECL_RTL (decl)) != MEM
3326 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3328 oldaddr = XEXP (DECL_RTL (decl), 0);
3332 = assign_stack_temp (DECL_MODE (decl),
3333 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3334 + BITS_PER_UNIT - 1)
3337 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3339 /* Set alignment we actually gave this decl. */
3340 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3341 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3345 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3346 if (addr != oldaddr)
3347 emit_move_insn (oldaddr, addr);
3350 /* If this is a memory ref that contains aggregate components,
3351 mark it as such for cse and loop optimize. */
3352 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3354 /* If this is in memory because of -ffloat-store,
3355 set the volatile bit, to prevent optimizations from
3356 undoing the effects. */
3357 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3358 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3362 /* Dynamic-size object: must push space on the stack. */
3366 /* Record the stack pointer on entry to block, if have
3367 not already done so. */
3368 if (thisblock->data.block.stack_level == 0)
3370 do_pending_stack_adjust ();
3371 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3372 &thisblock->data.block.stack_level,
3373 thisblock->data.block.first_insn);
3374 stack_block_stack = thisblock;
3377 /* Compute the variable's size, in bytes. */
3378 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3380 size_int (BITS_PER_UNIT)),
3381 NULL_RTX, VOIDmode, 0);
3384 /* Allocate space on the stack for the variable. */
3385 address = allocate_dynamic_stack_space (size, NULL_RTX,
3388 /* Reference the variable indirect through that rtx. */
3389 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3391 /* If this is a memory ref that contains aggregate components,
3392 mark it as such for cse and loop optimize. */
3393 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3395 /* Indicate the alignment we actually gave this variable. */
3396 #ifdef STACK_BOUNDARY
3397 DECL_ALIGN (decl) = STACK_BOUNDARY;
3399 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3403 if (TREE_THIS_VOLATILE (decl))
3404 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3405 #if 0 /* A variable is not necessarily unchanging
3406 just because it is const. RTX_UNCHANGING_P
3407 means no change in the function,
3408 not merely no change in the variable's scope.
3409 It is correct to set RTX_UNCHANGING_P if the variable's scope
3410 is the whole function. There's no convenient way to test that. */
3411 if (TREE_READONLY (decl))
3412 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3415 /* If doing stupid register allocation, make sure life of any
3416 register variable starts here, at the start of its scope. */
3419 use_variable (DECL_RTL (decl));
3423 /* Generate code for the automatic variable declaration DECL. For
3424 most variables this just means we give it a stack offset. The
3425 compiler sometimes emits cleanups without variables and we will
3426 have to deal with those too. */
3429 bc_expand_decl (decl, cleanup)
3437 /* A cleanup with no variable. */
3444 /* Only auto variables need any work. */
3445 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3448 type = TREE_TYPE (decl);
3450 if (type == error_mark_node)
3451 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3453 else if (DECL_SIZE (decl) == 0)
3455 /* Variable with incomplete type. The stack offset herein will be
3456 fixed later in expand_decl_init (). */
3457 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3459 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3461 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3465 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3468 /* Emit code to perform the initialization of a declaration DECL. */
3471 expand_decl_init (decl)
3474 int was_used = TREE_USED (decl);
3476 if (output_bytecode)
3478 bc_expand_decl_init (decl);
3482 /* If this is a CONST_DECL, we don't have to generate any code, but
3483 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3484 to be set while in the obstack containing the constant. If we don't
3485 do this, we can lose if we have functions nested three deep and the middle
3486 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3487 the innermost function is the first to expand that STRING_CST. */
3488 if (TREE_CODE (decl) == CONST_DECL)
3490 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3491 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3492 EXPAND_INITIALIZER);
3496 if (TREE_STATIC (decl))
3499 /* Compute and store the initial value now. */
3501 if (DECL_INITIAL (decl) == error_mark_node)
3503 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3504 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3505 || code == POINTER_TYPE)
3506 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3510 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3512 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3513 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3517 /* Don't let the initialization count as "using" the variable. */
3518 TREE_USED (decl) = was_used;
3520 /* Free any temporaries we made while initializing the decl. */
3524 /* Expand initialization for variable-sized types. Allocate array
3525 using newlocalSI and set local variable, which is a pointer to the
3529 bc_expand_variable_local_init (decl)
3532 /* Evaluate size expression and coerce to SI */
3533 bc_expand_expr (DECL_SIZE (decl));
3535 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3536 no coercion is necessary (?) */
3538 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3539 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3541 /* Emit code to allocate array */
3542 bc_emit_instruction (newlocalSI);
3544 /* Store array pointer in local variable. This is the only instance
3545 where we actually want the address of the pointer to the
3546 variable-size block, rather than the pointer itself. We avoid
3547 using expand_address() since that would cause the pointer to be
3548 pushed rather than its address. Hence the hard-coded reference;
3549 notice also that the variable is always local (no global
3550 variable-size type variables). */
3552 bc_load_localaddr (DECL_RTL (decl));
3553 bc_emit_instruction (storeP);
3557 /* Emit code to initialize a declaration. */
3560 bc_expand_decl_init (decl)
3563 int org_stack_depth;
3565 /* Statical initializers are handled elsewhere */
3567 if (TREE_STATIC (decl))
3570 /* Memory original stack depth */
3571 org_stack_depth = stack_depth;
3573 /* If the type is variable-size, we first create its space (we ASSUME
3574 it CAN'T be static). We do this regardless of whether there's an
3575 initializer assignment or not. */
3577 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3578 bc_expand_variable_local_init (decl);
3580 /* Expand initializer assignment */
3581 if (DECL_INITIAL (decl) == error_mark_node)
3583 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3585 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3586 || code == POINTER_TYPE)
3588 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3590 else if (DECL_INITIAL (decl))
3591 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3593 /* Restore stack depth */
3594 if (org_stack_depth > stack_depth)
3597 bc_adjust_stack (stack_depth - org_stack_depth);
3601 /* CLEANUP is an expression to be executed at exit from this binding contour;
3602 for example, in C++, it might call the destructor for this variable.
3604 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3605 either before or after calling `expand_decl' but before compiling
3606 any subsequent expressions. This is because CLEANUP may be expanded
3607 more than once, on different branches of execution.
3608 For the same reason, CLEANUP may not contain a CALL_EXPR
3609 except as its topmost node--else `preexpand_calls' would get confused.
3611 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3612 that is not associated with any particular variable. */
3615 expand_decl_cleanup (decl, cleanup)
3618 struct nesting *thisblock = block_stack;
3620 /* Error if we are not in any block. */
3624 /* Record the cleanup if there is one. */
3628 thisblock->data.block.cleanups
3629 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3630 /* If this block has a cleanup, it belongs in stack_block_stack. */
3631 stack_block_stack = thisblock;
3632 (*interim_eh_hook) (NULL_TREE);
3637 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3638 DECL_ELTS is the list of elements that belong to DECL's type.
3639 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3642 expand_anon_union_decl (decl, cleanup, decl_elts)
3643 tree decl, cleanup, decl_elts;
3645 struct nesting *thisblock = block_stack;
3648 expand_decl (decl, cleanup);
3649 x = DECL_RTL (decl);
3653 tree decl_elt = TREE_VALUE (decl_elts);
3654 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3655 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3657 /* Propagate the union's alignment to the elements. */
3658 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3660 /* If the element has BLKmode and the union doesn't, the union is
3661 aligned such that the element doesn't need to have BLKmode, so
3662 change the element's mode to the appropriate one for its size. */
3663 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3664 DECL_MODE (decl_elt) = mode
3665 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3668 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3669 instead create a new MEM rtx with the proper mode. */
3670 if (GET_CODE (x) == MEM)
3672 if (mode == GET_MODE (x))
3673 DECL_RTL (decl_elt) = x;
3676 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3677 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3678 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3681 else if (GET_CODE (x) == REG)
3683 if (mode == GET_MODE (x))
3684 DECL_RTL (decl_elt) = x;
3686 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3691 /* Record the cleanup if there is one. */
3694 thisblock->data.block.cleanups
3695 = temp_tree_cons (decl_elt, cleanup_elt,
3696 thisblock->data.block.cleanups);
3698 decl_elts = TREE_CHAIN (decl_elts);
3702 /* Expand a list of cleanups LIST.
3703 Elements may be expressions or may be nested lists.
3705 If DONT_DO is nonnull, then any list-element
3706 whose TREE_PURPOSE matches DONT_DO is omitted.
3707 This is sometimes used to avoid a cleanup associated with
3708 a value that is being returned out of the scope.
3710 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3711 goto and handle protection regions specially in that case.
3713 If REACHABLE, we emit code, otherwise just inform the exception handling
3714 code about this finalization. */
3717 expand_cleanups (list, dont_do, in_fixup, reachable)
3724 for (tail = list; tail; tail = TREE_CHAIN (tail))
3725 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3727 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3728 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3732 (*interim_eh_hook) (TREE_VALUE (tail));
3736 /* Cleanups may be run multiple times. For example,
3737 when exiting a binding contour, we expand the
3738 cleanups associated with that contour. When a goto
3739 within that binding contour has a target outside that
3740 contour, it will expand all cleanups from its scope to
3741 the target. Though the cleanups are expanded multiple
3742 times, the control paths are non-overlapping so the
3743 cleanups will not be executed twice. */
3744 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3751 /* Move all cleanups from the current block_stack
3752 to the containing block_stack, where they are assumed to
3753 have been created. If anything can cause a temporary to
3754 be created, but not expanded for more than one level of
3755 block_stacks, then this code will have to change. */
3760 struct nesting *block = block_stack;
3761 struct nesting *outer = block->next;
3763 outer->data.block.cleanups
3764 = chainon (block->data.block.cleanups,
3765 outer->data.block.cleanups);
3766 block->data.block.cleanups = 0;
3770 last_cleanup_this_contour ()
3772 if (block_stack == 0)
3775 return block_stack->data.block.cleanups;
3778 /* Return 1 if there are any pending cleanups at this point.
3779 If THIS_CONTOUR is nonzero, check the current contour as well.
3780 Otherwise, look only at the contours that enclose this one. */
3783 any_pending_cleanups (this_contour)
3786 struct nesting *block;
3788 if (block_stack == 0)
3791 if (this_contour && block_stack->data.block.cleanups != NULL)
3793 if (block_stack->data.block.cleanups == 0
3794 && (block_stack->data.block.outer_cleanups == 0
3796 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3801 for (block = block_stack->next; block; block = block->next)
3802 if (block->data.block.cleanups != 0)
3808 /* Enter a case (Pascal) or switch (C) statement.
3809 Push a block onto case_stack and nesting_stack
3810 to accumulate the case-labels that are seen
3811 and to record the labels generated for the statement.
3813 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3814 Otherwise, this construct is transparent for `exit_something'.
3816 EXPR is the index-expression to be dispatched on.
3817 TYPE is its nominal type. We could simply convert EXPR to this type,
3818 but instead we take short cuts. */
3821 expand_start_case (exit_flag, expr, type, printname)
3827 register struct nesting *thiscase = ALLOC_NESTING ();
3829 /* Make an entry on case_stack for the case we are entering. */
3831 thiscase->next = case_stack;
3832 thiscase->all = nesting_stack;
3833 thiscase->depth = ++nesting_depth;
3834 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3835 thiscase->data.case_stmt.case_list = 0;
3836 thiscase->data.case_stmt.index_expr = expr;
3837 thiscase->data.case_stmt.nominal_type = type;
3838 thiscase->data.case_stmt.default_label = 0;
3839 thiscase->data.case_stmt.num_ranges = 0;
3840 thiscase->data.case_stmt.printname = printname;
3841 thiscase->data.case_stmt.seenlabel = 0;
3842 case_stack = thiscase;
3843 nesting_stack = thiscase;
3845 if (output_bytecode)
3847 bc_expand_start_case (thiscase, expr, type, printname);
3851 do_pending_stack_adjust ();
3853 /* Make sure case_stmt.start points to something that won't
3854 need any transformation before expand_end_case. */
3855 if (GET_CODE (get_last_insn ()) != NOTE)
3856 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3858 thiscase->data.case_stmt.start = get_last_insn ();
3862 /* Enter a case statement. It is assumed that the caller has pushed
3863 the current context onto the case stack. */
3866 bc_expand_start_case (thiscase, expr, type, printname)
3867 struct nesting *thiscase;
3872 bc_expand_expr (expr);
3873 bc_expand_conversion (TREE_TYPE (expr), type);
3875 /* For cases, the skip is a place we jump to that's emitted after
3876 the size of the jump table is known. */
3878 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3879 bc_emit_bytecode (jump);
3880 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3882 #ifdef DEBUG_PRINT_CODE
3883 fputc ('\n', stderr);
3888 /* Start a "dummy case statement" within which case labels are invalid
3889 and are not connected to any larger real case statement.
3890 This can be used if you don't want to let a case statement jump
3891 into the middle of certain kinds of constructs. */
3894 expand_start_case_dummy ()
3896 register struct nesting *thiscase = ALLOC_NESTING ();
3898 /* Make an entry on case_stack for the dummy. */
3900 thiscase->next = case_stack;
3901 thiscase->all = nesting_stack;
3902 thiscase->depth = ++nesting_depth;
3903 thiscase->exit_label = 0;
3904 thiscase->data.case_stmt.case_list = 0;
3905 thiscase->data.case_stmt.start = 0;
3906 thiscase->data.case_stmt.nominal_type = 0;
3907 thiscase->data.case_stmt.default_label = 0;
3908 thiscase->data.case_stmt.num_ranges = 0;
3909 case_stack = thiscase;
3910 nesting_stack = thiscase;
3913 /* End a dummy case statement. */
3916 expand_end_case_dummy ()
3918 POPSTACK (case_stack);
3921 /* Return the data type of the index-expression
3922 of the innermost case statement, or null if none. */
3925 case_index_expr_type ()
3928 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3932 /* Accumulate one case or default label inside a case or switch statement.
3933 VALUE is the value of the case (a null pointer, for a default label).
3934 The function CONVERTER, when applied to arguments T and V,
3935 converts the value V to the type T.
3937 If not currently inside a case or switch statement, return 1 and do
3938 nothing. The caller will print a language-specific error message.
3939 If VALUE is a duplicate or overlaps, return 2 and do nothing
3940 except store the (first) duplicate node in *DUPLICATE.
3941 If VALUE is out of range, return 3 and do nothing.
3942 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3943 Return 0 on success.
3945 Extended to handle range statements. */
3948 pushcase (value, converter, label, duplicate)
3949 register tree value;
3950 tree (*converter) PROTO((tree, tree));
3951 register tree label;
3954 register struct case_node **l;
3955 register struct case_node *n;
3959 if (output_bytecode)
3960 return bc_pushcase (value, label);
3962 /* Fail if not inside a real case statement. */
3963 if (! (case_stack && case_stack->data.case_stmt.start))
3966 if (stack_block_stack
3967 && stack_block_stack->depth > case_stack->depth)
3970 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
3971 nominal_type = case_stack->data.case_stmt.nominal_type;
3973 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3974 if (index_type == error_mark_node)
3977 /* Convert VALUE to the type in which the comparisons are nominally done. */
3979 value = (*converter) (nominal_type, value);
3981 /* If this is the first label, warn if any insns have been emitted. */
3982 if (case_stack->data.case_stmt.seenlabel == 0)
3985 for (insn = case_stack->data.case_stmt.start;
3987 insn = NEXT_INSN (insn))
3989 if (GET_CODE (insn) == CODE_LABEL)
3991 if (GET_CODE (insn) != NOTE
3992 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
3994 warning ("unreachable code at beginning of %s",
3995 case_stack->data.case_stmt.printname);
4000 case_stack->data.case_stmt.seenlabel = 1;
4002 /* Fail if this value is out of range for the actual type of the index
4003 (which may be narrower than NOMINAL_TYPE). */
4004 if (value != 0 && ! int_fits_type_p (value, index_type))
4007 /* Fail if this is a duplicate or overlaps another entry. */
4010 if (case_stack->data.case_stmt.default_label != 0)
4012 *duplicate = case_stack->data.case_stmt.default_label;
4015 case_stack->data.case_stmt.default_label = label;
4019 /* Find the elt in the chain before which to insert the new value,
4020 to keep the chain sorted in increasing order.
4021 But report an error if this element is a duplicate. */
4022 for (l = &case_stack->data.case_stmt.case_list;
4023 /* Keep going past elements distinctly less than VALUE. */
4024 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4029 /* Element we will insert before must be distinctly greater;
4030 overlap means error. */
4031 if (! tree_int_cst_lt (value, (*l)->low))
4033 *duplicate = (*l)->code_label;
4038 /* Add this label to the chain, and succeed.
4039 Copy VALUE so it is on temporary rather than momentary
4040 obstack and will thus survive till the end of the case statement. */
4041 n = (struct case_node *) oballoc (sizeof (struct case_node));
4044 n->high = n->low = copy_node (value);
4045 n->code_label = label;
4049 expand_label (label);
4053 /* Like pushcase but this case applies to all values
4054 between VALUE1 and VALUE2 (inclusive).
4055 The return value is the same as that of pushcase
4056 but there is one additional error code:
4057 4 means the specified range was empty. */
4060 pushcase_range (value1, value2, converter, label, duplicate)
4061 register tree value1, value2;
4062 tree (*converter) PROTO((tree, tree));
4063 register tree label;
4066 register struct case_node **l;
4067 register struct case_node *n;
4071 /* Fail if not inside a real case statement. */
4072 if (! (case_stack && case_stack->data.case_stmt.start))
4075 if (stack_block_stack
4076 && stack_block_stack->depth > case_stack->depth)
4079 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4080 nominal_type = case_stack->data.case_stmt.nominal_type;
4082 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4083 if (index_type == error_mark_node)
4086 /* If this is the first label, warn if any insns have been emitted. */
4087 if (case_stack->data.case_stmt.seenlabel == 0)
4090 for (insn = case_stack->data.case_stmt.start;
4092 insn = NEXT_INSN (insn))
4094 if (GET_CODE (insn) == CODE_LABEL)
4096 if (GET_CODE (insn) != NOTE
4097 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4099 warning ("unreachable code at beginning of %s",
4100 case_stack->data.case_stmt.printname);
4105 case_stack->data.case_stmt.seenlabel = 1;
4107 /* Convert VALUEs to type in which the comparisons are nominally done. */
4108 if (value1 == 0) /* Negative infinity. */
4109 value1 = TYPE_MIN_VALUE(index_type);
4110 value1 = (*converter) (nominal_type, value1);
4112 if (value2 == 0) /* Positive infinity. */
4113 value2 = TYPE_MAX_VALUE(index_type);
4114 value2 = (*converter) (nominal_type, value2);
4116 /* Fail if these values are out of range. */
4117 if (! int_fits_type_p (value1, index_type))
4120 if (! int_fits_type_p (value2, index_type))
4123 /* Fail if the range is empty. */
4124 if (tree_int_cst_lt (value2, value1))
4127 /* If the bounds are equal, turn this into the one-value case. */
4128 if (tree_int_cst_equal (value1, value2))
4129 return pushcase (value1, converter, label, duplicate);
4131 /* Find the elt in the chain before which to insert the new value,
4132 to keep the chain sorted in increasing order.
4133 But report an error if this element is a duplicate. */
4134 for (l = &case_stack->data.case_stmt.case_list;
4135 /* Keep going past elements distinctly less than this range. */
4136 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4141 /* Element we will insert before must be distinctly greater;
4142 overlap means error. */
4143 if (! tree_int_cst_lt (value2, (*l)->low))
4145 *duplicate = (*l)->code_label;
4150 /* Add this label to the chain, and succeed.
4151 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4152 obstack and will thus survive till the end of the case statement. */
4154 n = (struct case_node *) oballoc (sizeof (struct case_node));
4157 n->low = copy_node (value1);
4158 n->high = copy_node (value2);
4159 n->code_label = label;
4162 expand_label (label);
4164 case_stack->data.case_stmt.num_ranges++;
4170 /* Accumulate one case or default label; VALUE is the value of the
4171 case, or nil for a default label. If not currently inside a case,
4172 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4173 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4174 Return 0 on success. This function is a leftover from the earlier
4175 bytecode compiler, which was based on gcc 1.37. It should be
4176 merged into pushcase. */
4179 bc_pushcase (value, label)
4183 struct nesting *thiscase = case_stack;
4184 struct case_node *case_label, *new_label;
4189 /* Fail if duplicate, overlap, or out of type range. */
4192 value = convert (thiscase->data.case_stmt.nominal_type, value);
4193 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4196 for (case_label = thiscase->data.case_stmt.case_list;
4197 case_label->left; case_label = case_label->left)
4198 if (! tree_int_cst_lt (case_label->left->high, value))
4201 if (case_label != thiscase->data.case_stmt.case_list
4202 && ! tree_int_cst_lt (case_label->high, value)
4203 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4206 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4207 new_label->low = new_label->high = copy_node (value);
4208 new_label->code_label = label;
4209 new_label->left = case_label->left;
4211 case_label->left = new_label;
4212 thiscase->data.case_stmt.num_ranges++;
4216 if (thiscase->data.case_stmt.default_label)
4218 thiscase->data.case_stmt.default_label = label;
4221 expand_label (label);
4225 /* Returns the number of possible values of TYPE.
4226 Returns -1 if the number is unknown or variable.
4227 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4228 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4229 do not increase monotonically (there may be duplicates);
4230 to 1 if the values increase monotonically, but not always by 1;
4231 otherwise sets it to 0. */
4234 all_cases_count (type, spareness)
4238 HOST_WIDE_INT count, count_high = 0;
4241 switch (TREE_CODE (type))
4248 count = 1 << BITS_PER_UNIT;
4252 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4253 || TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST)
4258 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4259 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4260 but with overflow checking. */
4261 tree mint = TYPE_MIN_VALUE (type);
4262 tree maxt = TYPE_MAX_VALUE (type);
4263 HOST_WIDE_INT lo, hi;
4264 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4266 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4268 add_double (lo, hi, 1, 0, &lo, &hi);
4269 if (hi != 0 || lo < 0)
4276 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4278 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4279 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4280 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4281 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4285 if (*spareness == 1)
4287 tree prev = TREE_VALUE (TYPE_VALUES (type));
4288 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4290 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4295 prev = TREE_VALUE (t);
4304 #define BITARRAY_TEST(ARRAY, INDEX) \
4305 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4306 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4307 #define BITARRAY_SET(ARRAY, INDEX) \
4308 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4309 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4311 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4312 with the case values we have seen, assuming the case expression
4314 SPARSENESS is as determined by all_cases_count.
4316 The time needed is propotional to COUNT, unless
4317 SPARSENESS is 2, in which case quadratic time is needed. */
4320 mark_seen_cases (type, cases_seen, count, sparseness)
4322 unsigned char *cases_seen;
4328 tree next_node_to_try = NULL_TREE;
4329 long next_node_offset = 0;
4331 register struct case_node *n;
4332 tree val = make_node (INTEGER_CST);
4333 TREE_TYPE (val) = type;
4334 for (n = case_stack->data.case_stmt.case_list; n;
4337 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4338 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4339 while ( ! tree_int_cst_lt (n->high, val))
4341 /* Calculate (into xlo) the "offset" of the integer (val).
4342 The element with lowest value has offset 0, the next smallest
4343 element has offset 1, etc. */
4345 HOST_WIDE_INT xlo, xhi;
4347 if (sparseness == 2)
4349 /* This less efficient loop is only needed to handle
4350 duplicate case values (multiple enum constants
4351 with the same value). */
4352 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4353 t = TREE_CHAIN (t), xlo++)
4355 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4356 BITARRAY_SET (cases_seen, xlo);
4361 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4363 /* The TYPE_VALUES will be in increasing order, so
4364 starting searching where we last ended. */
4365 t = next_node_to_try;
4366 xlo = next_node_offset;
4372 t = TYPE_VALUES (type);
4375 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4377 next_node_to_try = TREE_CHAIN (t);
4378 next_node_offset = xlo + 1;
4383 if (t == next_node_to_try)
4389 t = TYPE_MIN_VALUE (type);
4391 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4395 add_double (xlo, xhi,
4396 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4400 if (xhi == 0 && xlo >= 0 && xlo < count)
4401 BITARRAY_SET (cases_seen, xlo);
4403 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4405 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4410 /* Called when the index of a switch statement is an enumerated type
4411 and there is no default label.
4413 Checks that all enumeration literals are covered by the case
4414 expressions of a switch. Also, warn if there are any extra
4415 switch cases that are *not* elements of the enumerated type.
4417 If all enumeration literals were covered by the case expressions,
4418 turn one of the expressions into the default expression since it should
4419 not be possible to fall through such a switch. */
4422 check_for_full_enumeration_handling (type)
4425 register struct case_node *n;
4426 register struct case_node **l;
4427 register tree chain;
4430 /* True iff the selector type is a numbered set mode. */
4433 /* The number of possible selector values. */
4436 /* For each possible selector value. a one iff it has been matched
4437 by a case value alternative. */
4438 unsigned char *cases_seen;
4440 /* The allocated size of cases_seen, in chars. */
4444 if (output_bytecode)
4446 bc_check_for_full_enumeration_handling (type);
4453 size = all_cases_count (type, &sparseness);
4454 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4456 if (size > 0 && size < 600000
4457 /* We deliberately use malloc here - not xmalloc. */
4458 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4461 tree v = TYPE_VALUES (type);
4462 bzero (cases_seen, bytes_needed);
4464 /* The time complexity of this code is normally O(N), where
4465 N being the number of members in the enumerated type.
4466 However, if type is a ENUMERAL_TYPE whose values do not
4467 increase monotonically, quadratic time may be needed. */
4469 mark_seen_cases (type, cases_seen, size, sparseness);
4471 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4473 if (BITARRAY_TEST(cases_seen, i) == 0)
4474 warning ("enumeration value `%s' not handled in switch",
4475 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4481 /* Now we go the other way around; we warn if there are case
4482 expressions that don't correspond to enumerators. This can
4483 occur since C and C++ don't enforce type-checking of
4484 assignments to enumeration variables. */
4487 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4489 for (chain = TYPE_VALUES (type);
4490 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4491 chain = TREE_CHAIN (chain))
4496 if (TYPE_NAME (type) == 0)
4497 warning ("case value `%d' not in enumerated type",
4498 TREE_INT_CST_LOW (n->low));
4500 warning ("case value `%d' not in enumerated type `%s'",
4501 TREE_INT_CST_LOW (n->low),
4502 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4505 : DECL_NAME (TYPE_NAME (type))));
4507 if (!tree_int_cst_equal (n->low, n->high))
4509 for (chain = TYPE_VALUES (type);
4510 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4511 chain = TREE_CHAIN (chain))
4516 if (TYPE_NAME (type) == 0)
4517 warning ("case value `%d' not in enumerated type",
4518 TREE_INT_CST_LOW (n->high));
4520 warning ("case value `%d' not in enumerated type `%s'",
4521 TREE_INT_CST_LOW (n->high),
4522 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4525 : DECL_NAME (TYPE_NAME (type))));
4531 /* ??? This optimization is disabled because it causes valid programs to
4532 fail. ANSI C does not guarantee that an expression with enum type
4533 will have a value that is the same as one of the enumation literals. */
4535 /* If all values were found as case labels, make one of them the default
4536 label. Thus, this switch will never fall through. We arbitrarily pick
4537 the last one to make the default since this is likely the most
4538 efficient choice. */
4542 for (l = &case_stack->data.case_stmt.case_list;
4547 case_stack->data.case_stmt.default_label = (*l)->code_label;
4554 /* Check that all enumeration literals are covered by the case
4555 expressions of a switch. Also warn if there are any cases
4556 that are not elements of the enumerated type. */
4559 bc_check_for_full_enumeration_handling (type)
4562 struct nesting *thiscase = case_stack;
4563 struct case_node *c;
4566 /* Check for enums not handled. */
4567 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4569 for (c = thiscase->data.case_stmt.case_list->left;
4570 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4573 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4574 warning ("enumerated value `%s' not handled in switch",
4575 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4578 /* Check for cases not in the enumeration. */
4579 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4581 for (e = TYPE_VALUES (type);
4582 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4586 warning ("case value `%d' not in enumerated type `%s'",
4587 TREE_INT_CST_LOW (c->low),
4588 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4590 : DECL_NAME (TYPE_NAME (type))));
4594 /* Terminate a case (Pascal) or switch (C) statement
4595 in which ORIG_INDEX is the expression to be tested.
4596 Generate the code to test it and jump to the right place. */
4599 expand_end_case (orig_index)
4602 tree minval, maxval, range, orig_minval;
4603 rtx default_label = 0;
4604 register struct case_node *n;
4612 register struct nesting *thiscase = case_stack;
4613 tree index_expr, index_type;
4616 if (output_bytecode)
4618 bc_expand_end_case (orig_index);
4622 table_label = gen_label_rtx ();
4623 index_expr = thiscase->data.case_stmt.index_expr;
4624 index_type = TREE_TYPE (index_expr);
4625 unsignedp = TREE_UNSIGNED (index_type);
4627 do_pending_stack_adjust ();
4629 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4630 if (index_type != error_mark_node)
4632 /* If switch expression was an enumerated type, check that all
4633 enumeration literals are covered by the cases.
4634 No sense trying this if there's a default case, however. */
4636 if (!thiscase->data.case_stmt.default_label
4637 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4638 && TREE_CODE (index_expr) != INTEGER_CST)
4639 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4641 /* If this is the first label, warn if any insns have been emitted. */
4642 if (thiscase->data.case_stmt.seenlabel == 0)
4645 for (insn = get_last_insn ();
4646 insn != case_stack->data.case_stmt.start;
4647 insn = PREV_INSN (insn))
4648 if (GET_CODE (insn) != NOTE
4649 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4651 warning ("unreachable code at beginning of %s",
4652 case_stack->data.case_stmt.printname);
4657 /* If we don't have a default-label, create one here,
4658 after the body of the switch. */
4659 if (thiscase->data.case_stmt.default_label == 0)
4661 thiscase->data.case_stmt.default_label
4662 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4663 expand_label (thiscase->data.case_stmt.default_label);
4665 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4667 before_case = get_last_insn ();
4669 /* Simplify the case-list before we count it. */
4670 group_case_nodes (thiscase->data.case_stmt.case_list);
4672 /* Get upper and lower bounds of case values.
4673 Also convert all the case values to the index expr's data type. */
4676 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4678 /* Check low and high label values are integers. */
4679 if (TREE_CODE (n->low) != INTEGER_CST)
4681 if (TREE_CODE (n->high) != INTEGER_CST)
4684 n->low = convert (index_type, n->low);
4685 n->high = convert (index_type, n->high);
4687 /* Count the elements and track the largest and smallest
4688 of them (treating them as signed even if they are not). */
4696 if (INT_CST_LT (n->low, minval))
4698 if (INT_CST_LT (maxval, n->high))
4701 /* A range counts double, since it requires two compares. */
4702 if (! tree_int_cst_equal (n->low, n->high))
4706 orig_minval = minval;
4708 /* Compute span of values. */
4710 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4714 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4716 emit_jump (default_label);
4719 /* If range of values is much bigger than number of values,
4720 make a sequence of conditional branches instead of a dispatch.
4721 If the switch-index is a constant, do it this way
4722 because we can optimize it. */
4724 #ifndef CASE_VALUES_THRESHOLD
4726 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4728 /* If machine does not have a case insn that compares the
4729 bounds, this means extra overhead for dispatch tables
4730 which raises the threshold for using them. */
4731 #define CASE_VALUES_THRESHOLD 5
4732 #endif /* HAVE_casesi */
4733 #endif /* CASE_VALUES_THRESHOLD */
4735 else if (TREE_INT_CST_HIGH (range) != 0
4736 || count < CASE_VALUES_THRESHOLD
4737 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4739 || TREE_CODE (index_expr) == INTEGER_CST
4740 /* These will reduce to a constant. */
4741 || (TREE_CODE (index_expr) == CALL_EXPR
4742 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4743 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4744 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4745 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4746 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4748 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4750 /* If the index is a short or char that we do not have
4751 an insn to handle comparisons directly, convert it to
4752 a full integer now, rather than letting each comparison
4753 generate the conversion. */
4755 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4756 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4757 == CODE_FOR_nothing))
4759 enum machine_mode wider_mode;
4760 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4761 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4762 if (cmp_optab->handlers[(int) wider_mode].insn_code
4763 != CODE_FOR_nothing)
4765 index = convert_to_mode (wider_mode, index, unsignedp);
4771 do_pending_stack_adjust ();
4773 index = protect_from_queue (index, 0);
4774 if (GET_CODE (index) == MEM)
4775 index = copy_to_reg (index);
4776 if (GET_CODE (index) == CONST_INT
4777 || TREE_CODE (index_expr) == INTEGER_CST)
4779 /* Make a tree node with the proper constant value
4780 if we don't already have one. */
4781 if (TREE_CODE (index_expr) != INTEGER_CST)
4784 = build_int_2 (INTVAL (index),
4785 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4786 index_expr = convert (index_type, index_expr);
4789 /* For constant index expressions we need only
4790 issue a unconditional branch to the appropriate
4791 target code. The job of removing any unreachable
4792 code is left to the optimisation phase if the
4793 "-O" option is specified. */
4794 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4795 if (! tree_int_cst_lt (index_expr, n->low)
4796 && ! tree_int_cst_lt (n->high, index_expr))
4800 emit_jump (label_rtx (n->code_label));
4802 emit_jump (default_label);
4806 /* If the index expression is not constant we generate
4807 a binary decision tree to select the appropriate
4808 target code. This is done as follows:
4810 The list of cases is rearranged into a binary tree,
4811 nearly optimal assuming equal probability for each case.
4813 The tree is transformed into RTL, eliminating
4814 redundant test conditions at the same time.
4816 If program flow could reach the end of the
4817 decision tree an unconditional jump to the
4818 default code is emitted. */
4821 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4822 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4823 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4825 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4826 default_label, index_type);
4827 emit_jump_if_reachable (default_label);
4836 enum machine_mode index_mode = SImode;
4837 int index_bits = GET_MODE_BITSIZE (index_mode);
4839 enum machine_mode op_mode;
4841 /* Convert the index to SImode. */
4842 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4843 > GET_MODE_BITSIZE (index_mode))
4845 enum machine_mode omode = TYPE_MODE (index_type);
4846 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4848 /* We must handle the endpoints in the original mode. */
4849 index_expr = build (MINUS_EXPR, index_type,
4850 index_expr, minval);
4851 minval = integer_zero_node;
4852 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4853 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4854 emit_jump_insn (gen_bltu (default_label));
4855 /* Now we can safely truncate. */
4856 index = convert_to_mode (index_mode, index, 0);
4860 if (TYPE_MODE (index_type) != index_mode)
4862 index_expr = convert (type_for_size (index_bits, 0),
4864 index_type = TREE_TYPE (index_expr);
4867 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4870 index = protect_from_queue (index, 0);
4871 do_pending_stack_adjust ();
4873 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4874 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4876 index = copy_to_mode_reg (op_mode, index);
4878 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4880 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4881 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4883 op1 = copy_to_mode_reg (op_mode, op1);
4885 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4887 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4888 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4890 op2 = copy_to_mode_reg (op_mode, op2);
4892 emit_jump_insn (gen_casesi (index, op1, op2,
4893 table_label, default_label));
4897 #ifdef HAVE_tablejump
4898 if (! win && HAVE_tablejump)
4900 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4901 fold (build (MINUS_EXPR, index_type,
4902 index_expr, minval)));
4903 index_type = TREE_TYPE (index_expr);
4904 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4906 index = protect_from_queue (index, 0);
4907 do_pending_stack_adjust ();
4909 do_tablejump (index, TYPE_MODE (index_type),
4910 expand_expr (range, NULL_RTX, VOIDmode, 0),
4911 table_label, default_label);
4918 /* Get table of labels to jump to, in order of case index. */
4920 ncases = TREE_INT_CST_LOW (range) + 1;
4921 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4922 bzero ((char *) labelvec, ncases * sizeof (rtx));
4924 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4926 register HOST_WIDE_INT i
4927 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4932 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4933 if (i + TREE_INT_CST_LOW (orig_minval)
4934 == TREE_INT_CST_LOW (n->high))
4940 /* Fill in the gaps with the default. */
4941 for (i = 0; i < ncases; i++)
4942 if (labelvec[i] == 0)
4943 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4945 /* Output the table */
4946 emit_label (table_label);
4948 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
4949 were an expression, instead of an #ifdef/#ifndef. */
4951 #ifdef CASE_VECTOR_PC_RELATIVE
4955 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
4956 gen_rtx (LABEL_REF, Pmode, table_label),
4957 gen_rtvec_v (ncases, labelvec)));
4959 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
4960 gen_rtvec_v (ncases, labelvec)));
4962 /* If the case insn drops through the table,
4963 after the table we must jump to the default-label.
4964 Otherwise record no drop-through after the table. */
4965 #ifdef CASE_DROPS_THROUGH
4966 emit_jump (default_label);
4972 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
4973 reorder_insns (before_case, get_last_insn (),
4974 thiscase->data.case_stmt.start);
4977 if (thiscase->exit_label)
4978 emit_label (thiscase->exit_label);
4980 POPSTACK (case_stack);
4986 /* Terminate a case statement. EXPR is the original index
4990 bc_expand_end_case (expr)
4993 struct nesting *thiscase = case_stack;
4994 enum bytecode_opcode opcode;
4995 struct bc_label *jump_label;
4996 struct case_node *c;
4998 bc_emit_bytecode (jump);
4999 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5001 #ifdef DEBUG_PRINT_CODE
5002 fputc ('\n', stderr);
5005 /* Now that the size of the jump table is known, emit the actual
5006 indexed jump instruction. */
5007 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5009 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5010 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5011 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5013 bc_emit_bytecode (opcode);
5015 /* Now emit the case instructions literal arguments, in order.
5016 In addition to the value on the stack, it uses:
5017 1. The address of the jump table.
5018 2. The size of the jump table.
5019 3. The default label. */
5021 jump_label = bc_get_bytecode_label ();
5022 bc_emit_bytecode_labelref (jump_label);
5023 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5024 sizeof thiscase->data.case_stmt.num_ranges);
5026 if (thiscase->data.case_stmt.default_label)
5027 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5029 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5031 /* Output the jump table. */
5033 bc_align_bytecode (3 /* PTR_ALIGN */);
5034 bc_emit_bytecode_labeldef (jump_label);
5036 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5037 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5039 opcode = TREE_INT_CST_LOW (c->low);
5040 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5042 opcode = TREE_INT_CST_LOW (c->high);
5043 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5045 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5048 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5049 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5051 bc_emit_bytecode_DI_const (c->low);
5052 bc_emit_bytecode_DI_const (c->high);
5054 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5061 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5063 /* Possibly issue enumeration warnings. */
5065 if (!thiscase->data.case_stmt.default_label
5066 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5067 && TREE_CODE (expr) != INTEGER_CST
5069 check_for_full_enumeration_handling (TREE_TYPE (expr));
5072 #ifdef DEBUG_PRINT_CODE
5073 fputc ('\n', stderr);
5076 POPSTACK (case_stack);
5080 /* Return unique bytecode ID. */
5085 static int bc_uid = 0;
5090 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5093 do_jump_if_equal (op1, op2, label, unsignedp)
5094 rtx op1, op2, label;
5097 if (GET_CODE (op1) == CONST_INT
5098 && GET_CODE (op2) == CONST_INT)
5100 if (INTVAL (op1) == INTVAL (op2))
5105 enum machine_mode mode = GET_MODE (op1);
5106 if (mode == VOIDmode)
5107 mode = GET_MODE (op2);
5108 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5109 emit_jump_insn (gen_beq (label));
5113 /* Not all case values are encountered equally. This function
5114 uses a heuristic to weight case labels, in cases where that
5115 looks like a reasonable thing to do.
5117 Right now, all we try to guess is text, and we establish the
5120 chars above space: 16
5129 If we find any cases in the switch that are not either -1 or in the range
5130 of valid ASCII characters, or are control characters other than those
5131 commonly used with "\", don't treat this switch scanning text.
5133 Return 1 if these nodes are suitable for cost estimation, otherwise
5137 estimate_case_costs (node)
5140 tree min_ascii = build_int_2 (-1, -1);
5141 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5145 /* If we haven't already made the cost table, make it now. Note that the
5146 lower bound of the table is -1, not zero. */
5148 if (cost_table == NULL)
5150 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5151 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5153 for (i = 0; i < 128; i++)
5157 else if (ispunct (i))
5159 else if (iscntrl (i))
5163 cost_table[' '] = 8;
5164 cost_table['\t'] = 4;
5165 cost_table['\0'] = 4;
5166 cost_table['\n'] = 2;
5167 cost_table['\f'] = 1;
5168 cost_table['\v'] = 1;
5169 cost_table['\b'] = 1;
5172 /* See if all the case expressions look like text. It is text if the
5173 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5174 as signed arithmetic since we don't want to ever access cost_table with a
5175 value less than -1. Also check that none of the constants in a range
5176 are strange control characters. */
5178 for (n = node; n; n = n->right)
5180 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5183 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5184 if (cost_table[i] < 0)
5188 /* All interesting values are within the range of interesting
5189 ASCII characters. */
5193 /* Scan an ordered list of case nodes
5194 combining those with consecutive values or ranges.
5196 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5199 group_case_nodes (head)
5202 case_node_ptr node = head;
5206 rtx lb = next_real_insn (label_rtx (node->code_label));
5207 case_node_ptr np = node;
5209 /* Try to group the successors of NODE with NODE. */
5210 while (((np = np->right) != 0)
5211 /* Do they jump to the same place? */
5212 && next_real_insn (label_rtx (np->code_label)) == lb
5213 /* Are their ranges consecutive? */
5214 && tree_int_cst_equal (np->low,
5215 fold (build (PLUS_EXPR,
5216 TREE_TYPE (node->high),
5219 /* An overflow is not consecutive. */
5220 && tree_int_cst_lt (node->high,
5221 fold (build (PLUS_EXPR,
5222 TREE_TYPE (node->high),
5224 integer_one_node))))
5226 node->high = np->high;
5228 /* NP is the first node after NODE which can't be grouped with it.
5229 Delete the nodes in between, and move on to that node. */
5235 /* Take an ordered list of case nodes
5236 and transform them into a near optimal binary tree,
5237 on the assumption that any target code selection value is as
5238 likely as any other.
5240 The transformation is performed by splitting the ordered
5241 list into two equal sections plus a pivot. The parts are
5242 then attached to the pivot as left and right branches. Each
5243 branch is is then transformed recursively. */
5246 balance_case_nodes (head, parent)
5247 case_node_ptr *head;
5248 case_node_ptr parent;
5250 register case_node_ptr np;
5258 register case_node_ptr *npp;
5261 /* Count the number of entries on branch. Also count the ranges. */
5265 if (!tree_int_cst_equal (np->low, np->high))
5269 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5273 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5281 /* Split this list if it is long enough for that to help. */
5286 /* Find the place in the list that bisects the list's total cost,
5287 Here I gets half the total cost. */
5292 /* Skip nodes while their cost does not reach that amount. */
5293 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5294 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5295 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5298 npp = &(*npp)->right;
5303 /* Leave this branch lopsided, but optimize left-hand
5304 side and fill in `parent' fields for right-hand side. */
5306 np->parent = parent;
5307 balance_case_nodes (&np->left, np);
5308 for (; np->right; np = np->right)
5309 np->right->parent = np;
5313 /* If there are just three nodes, split at the middle one. */
5315 npp = &(*npp)->right;
5318 /* Find the place in the list that bisects the list's total cost,
5319 where ranges count as 2.
5320 Here I gets half the total cost. */
5321 i = (i + ranges + 1) / 2;
5324 /* Skip nodes while their cost does not reach that amount. */
5325 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5330 npp = &(*npp)->right;
5335 np->parent = parent;
5338 /* Optimize each of the two split parts. */
5339 balance_case_nodes (&np->left, np);
5340 balance_case_nodes (&np->right, np);
5344 /* Else leave this branch as one level,
5345 but fill in `parent' fields. */
5347 np->parent = parent;
5348 for (; np->right; np = np->right)
5349 np->right->parent = np;
5354 /* Search the parent sections of the case node tree
5355 to see if a test for the lower bound of NODE would be redundant.
5356 INDEX_TYPE is the type of the index expression.
5358 The instructions to generate the case decision tree are
5359 output in the same order as nodes are processed so it is
5360 known that if a parent node checks the range of the current
5361 node minus one that the current node is bounded at its lower
5362 span. Thus the test would be redundant. */
5365 node_has_low_bound (node, index_type)
5370 case_node_ptr pnode;
5372 /* If the lower bound of this node is the lowest value in the index type,
5373 we need not test it. */
5375 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5378 /* If this node has a left branch, the value at the left must be less
5379 than that at this node, so it cannot be bounded at the bottom and
5380 we need not bother testing any further. */
5385 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5386 node->low, integer_one_node));
5388 /* If the subtraction above overflowed, we can't verify anything.
5389 Otherwise, look for a parent that tests our value - 1. */
5391 if (! tree_int_cst_lt (low_minus_one, node->low))
5394 for (pnode = node->parent; pnode; pnode = pnode->parent)
5395 if (tree_int_cst_equal (low_minus_one, pnode->high))
5401 /* Search the parent sections of the case node tree
5402 to see if a test for the upper bound of NODE would be redundant.
5403 INDEX_TYPE is the type of the index expression.
5405 The instructions to generate the case decision tree are
5406 output in the same order as nodes are processed so it is
5407 known that if a parent node checks the range of the current
5408 node plus one that the current node is bounded at its upper
5409 span. Thus the test would be redundant. */
5412 node_has_high_bound (node, index_type)
5417 case_node_ptr pnode;
5419 /* If the upper bound of this node is the highest value in the type
5420 of the index expression, we need not test against it. */
5422 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5425 /* If this node has a right branch, the value at the right must be greater
5426 than that at this node, so it cannot be bounded at the top and
5427 we need not bother testing any further. */
5432 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5433 node->high, integer_one_node));
5435 /* If the addition above overflowed, we can't verify anything.
5436 Otherwise, look for a parent that tests our value + 1. */
5438 if (! tree_int_cst_lt (node->high, high_plus_one))
5441 for (pnode = node->parent; pnode; pnode = pnode->parent)
5442 if (tree_int_cst_equal (high_plus_one, pnode->low))
5448 /* Search the parent sections of the
5449 case node tree to see if both tests for the upper and lower
5450 bounds of NODE would be redundant. */
5453 node_is_bounded (node, index_type)
5457 return (node_has_low_bound (node, index_type)
5458 && node_has_high_bound (node, index_type));
5461 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5464 emit_jump_if_reachable (label)
5467 if (GET_CODE (get_last_insn ()) != BARRIER)
5471 /* Emit step-by-step code to select a case for the value of INDEX.
5472 The thus generated decision tree follows the form of the
5473 case-node binary tree NODE, whose nodes represent test conditions.
5474 INDEX_TYPE is the type of the index of the switch.
5476 Care is taken to prune redundant tests from the decision tree
5477 by detecting any boundary conditions already checked by
5478 emitted rtx. (See node_has_high_bound, node_has_low_bound
5479 and node_is_bounded, above.)
5481 Where the test conditions can be shown to be redundant we emit
5482 an unconditional jump to the target code. As a further
5483 optimization, the subordinates of a tree node are examined to
5484 check for bounded nodes. In this case conditional and/or
5485 unconditional jumps as a result of the boundary check for the
5486 current node are arranged to target the subordinates associated
5487 code for out of bound conditions on the current node node.
5489 We can assume that when control reaches the code generated here,
5490 the index value has already been compared with the parents
5491 of this node, and determined to be on the same side of each parent
5492 as this node is. Thus, if this node tests for the value 51,
5493 and a parent tested for 52, we don't need to consider
5494 the possibility of a value greater than 51. If another parent
5495 tests for the value 50, then this node need not test anything. */
5498 emit_case_nodes (index, node, default_label, index_type)
5504 /* If INDEX has an unsigned type, we must make unsigned branches. */
5505 int unsignedp = TREE_UNSIGNED (index_type);
5506 typedef rtx rtx_function ();
5507 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5508 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5509 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5510 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5511 enum machine_mode mode = GET_MODE (index);
5513 /* See if our parents have already tested everything for us.
5514 If they have, emit an unconditional jump for this node. */
5515 if (node_is_bounded (node, index_type))
5516 emit_jump (label_rtx (node->code_label));
5518 else if (tree_int_cst_equal (node->low, node->high))
5520 /* Node is single valued. First see if the index expression matches
5521 this node and then check our children, if any. */
5523 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5524 label_rtx (node->code_label), unsignedp);
5526 if (node->right != 0 && node->left != 0)
5528 /* This node has children on both sides.
5529 Dispatch to one side or the other
5530 by comparing the index value with this node's value.
5531 If one subtree is bounded, check that one first,
5532 so we can avoid real branches in the tree. */
5534 if (node_is_bounded (node->right, index_type))
5536 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5538 GT, NULL_RTX, mode, unsignedp, 0);
5540 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5541 emit_case_nodes (index, node->left, default_label, index_type);
5544 else if (node_is_bounded (node->left, index_type))
5546 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5548 LT, NULL_RTX, mode, unsignedp, 0);
5549 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5550 emit_case_nodes (index, node->right, default_label, index_type);
5555 /* Neither node is bounded. First distinguish the two sides;
5556 then emit the code for one side at a time. */
5559 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5561 /* See if the value is on the right. */
5562 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5564 GT, NULL_RTX, mode, unsignedp, 0);
5565 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5567 /* Value must be on the left.
5568 Handle the left-hand subtree. */
5569 emit_case_nodes (index, node->left, default_label, index_type);
5570 /* If left-hand subtree does nothing,
5572 emit_jump_if_reachable (default_label);
5574 /* Code branches here for the right-hand subtree. */
5575 expand_label (test_label);
5576 emit_case_nodes (index, node->right, default_label, index_type);
5580 else if (node->right != 0 && node->left == 0)
5582 /* Here we have a right child but no left so we issue conditional
5583 branch to default and process the right child.
5585 Omit the conditional branch to default if we it avoid only one
5586 right child; it costs too much space to save so little time. */
5588 if (node->right->right || node->right->left
5589 || !tree_int_cst_equal (node->right->low, node->right->high))
5591 if (!node_has_low_bound (node, index_type))
5593 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5595 LT, NULL_RTX, mode, unsignedp, 0);
5596 emit_jump_insn ((*gen_blt_pat) (default_label));
5599 emit_case_nodes (index, node->right, default_label, index_type);
5602 /* We cannot process node->right normally
5603 since we haven't ruled out the numbers less than
5604 this node's value. So handle node->right explicitly. */
5605 do_jump_if_equal (index,
5606 expand_expr (node->right->low, NULL_RTX,
5608 label_rtx (node->right->code_label), unsignedp);
5611 else if (node->right == 0 && node->left != 0)
5613 /* Just one subtree, on the left. */
5615 #if 0 /* The following code and comment were formerly part
5616 of the condition here, but they didn't work
5617 and I don't understand what the idea was. -- rms. */
5618 /* If our "most probable entry" is less probable
5619 than the default label, emit a jump to
5620 the default label using condition codes
5621 already lying around. With no right branch,
5622 a branch-greater-than will get us to the default
5625 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5628 if (node->left->left || node->left->right
5629 || !tree_int_cst_equal (node->left->low, node->left->high))
5631 if (!node_has_high_bound (node, index_type))
5633 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5635 GT, NULL_RTX, mode, unsignedp, 0);
5636 emit_jump_insn ((*gen_bgt_pat) (default_label));
5639 emit_case_nodes (index, node->left, default_label, index_type);
5642 /* We cannot process node->left normally
5643 since we haven't ruled out the numbers less than
5644 this node's value. So handle node->left explicitly. */
5645 do_jump_if_equal (index,
5646 expand_expr (node->left->low, NULL_RTX,
5648 label_rtx (node->left->code_label), unsignedp);
5653 /* Node is a range. These cases are very similar to those for a single
5654 value, except that we do not start by testing whether this node
5655 is the one to branch to. */
5657 if (node->right != 0 && node->left != 0)
5659 /* Node has subtrees on both sides.
5660 If the right-hand subtree is bounded,
5661 test for it first, since we can go straight there.
5662 Otherwise, we need to make a branch in the control structure,
5663 then handle the two subtrees. */
5664 tree test_label = 0;
5666 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5668 GT, NULL_RTX, mode, unsignedp, 0);
5670 if (node_is_bounded (node->right, index_type))
5671 /* Right hand node is fully bounded so we can eliminate any
5672 testing and branch directly to the target code. */
5673 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5676 /* Right hand node requires testing.
5677 Branch to a label where we will handle it later. */
5679 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5680 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5683 /* Value belongs to this node or to the left-hand subtree. */
5685 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5686 GE, NULL_RTX, mode, unsignedp, 0);
5687 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5689 /* Handle the left-hand subtree. */
5690 emit_case_nodes (index, node->left, default_label, index_type);
5692 /* If right node had to be handled later, do that now. */
5696 /* If the left-hand subtree fell through,
5697 don't let it fall into the right-hand subtree. */
5698 emit_jump_if_reachable (default_label);
5700 expand_label (test_label);
5701 emit_case_nodes (index, node->right, default_label, index_type);
5705 else if (node->right != 0 && node->left == 0)
5707 /* Deal with values to the left of this node,
5708 if they are possible. */
5709 if (!node_has_low_bound (node, index_type))
5711 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5713 LT, NULL_RTX, mode, unsignedp, 0);
5714 emit_jump_insn ((*gen_blt_pat) (default_label));
5717 /* Value belongs to this node or to the right-hand subtree. */
5719 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5721 LE, NULL_RTX, mode, unsignedp, 0);
5722 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5724 emit_case_nodes (index, node->right, default_label, index_type);
5727 else if (node->right == 0 && node->left != 0)
5729 /* Deal with values to the right of this node,
5730 if they are possible. */
5731 if (!node_has_high_bound (node, index_type))
5733 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5735 GT, NULL_RTX, mode, unsignedp, 0);
5736 emit_jump_insn ((*gen_bgt_pat) (default_label));
5739 /* Value belongs to this node or to the left-hand subtree. */
5741 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5742 GE, NULL_RTX, mode, unsignedp, 0);
5743 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5745 emit_case_nodes (index, node->left, default_label, index_type);
5750 /* Node has no children so we check low and high bounds to remove
5751 redundant tests. Only one of the bounds can exist,
5752 since otherwise this node is bounded--a case tested already. */
5754 if (!node_has_high_bound (node, index_type))
5756 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5758 GT, NULL_RTX, mode, unsignedp, 0);
5759 emit_jump_insn ((*gen_bgt_pat) (default_label));
5762 if (!node_has_low_bound (node, index_type))
5764 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5766 LT, NULL_RTX, mode, unsignedp, 0);
5767 emit_jump_insn ((*gen_blt_pat) (default_label));
5770 emit_jump (label_rtx (node->code_label));
5775 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5776 so that the debugging info will be correct for the unrolled loop. */
5778 /* Indexed by block number, contains a pointer to the N'th block node. */
5780 static tree *block_vector;
5783 find_loop_tree_blocks ()
5785 tree block = DECL_INITIAL (current_function_decl);
5787 /* There first block is for the function body, and does not have
5788 corresponding block notes. Don't include it in the block vector. */
5789 block = BLOCK_SUBBLOCKS (block);
5791 block_vector = identify_blocks (block, get_insns ());
5795 unroll_block_trees ()
5797 tree block = DECL_INITIAL (current_function_decl);
5799 reorder_blocks (block_vector, block, get_insns ());