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 #ifdef POINTERS_EXTEND_UNSIGNED
614 x = convert_memory_address (Pmode, x);
618 do_pending_stack_adjust ();
619 emit_indirect_jump (x);
623 /* Handle goto statements and the labels that they can go to. */
625 /* Specify the location in the RTL code of a label LABEL,
626 which is a LABEL_DECL tree node.
628 This is used for the kind of label that the user can jump to with a
629 goto statement, and for alternatives of a switch or case statement.
630 RTL labels generated for loops and conditionals don't go through here;
631 they are generated directly at the RTL level, by other functions below.
633 Note that this has nothing to do with defining label *names*.
634 Languages vary in how they do that and what that even means. */
640 struct label_chain *p;
644 if (! DECL_RTL (label))
645 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
646 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
647 error ("multiply defined label");
651 do_pending_stack_adjust ();
652 emit_label (label_rtx (label));
653 if (DECL_NAME (label))
654 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
656 if (stack_block_stack != 0)
658 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
659 p->next = stack_block_stack->data.block.label_chain;
660 stack_block_stack->data.block.label_chain = p;
665 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
666 from nested functions. */
669 declare_nonlocal_label (label)
672 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
673 LABEL_PRESERVE_P (label_rtx (label)) = 1;
674 if (nonlocal_goto_handler_slot == 0)
676 nonlocal_goto_handler_slot
677 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
678 emit_stack_save (SAVE_NONLOCAL,
679 &nonlocal_goto_stack_level,
680 PREV_INSN (tail_recursion_reentry));
684 /* Generate RTL code for a `goto' statement with target label LABEL.
685 LABEL should be a LABEL_DECL tree node that was or will later be
686 defined with `expand_label'. */
696 expand_goto_internal (label, label_rtx (label), NULL_RTX);
700 /* Check for a nonlocal goto to a containing function. */
701 context = decl_function_context (label);
702 if (context != 0 && context != current_function_decl)
704 struct function *p = find_function_data (context);
705 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
708 p->has_nonlocal_label = 1;
709 current_function_has_nonlocal_goto = 1;
710 LABEL_REF_NONLOCAL_P (label_ref) = 1;
712 /* Copy the rtl for the slots so that they won't be shared in
713 case the virtual stack vars register gets instantiated differently
714 in the parent than in the child. */
716 #if HAVE_nonlocal_goto
717 if (HAVE_nonlocal_goto)
718 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
719 copy_rtx (p->nonlocal_goto_handler_slot),
720 copy_rtx (p->nonlocal_goto_stack_level),
727 /* Restore frame pointer for containing function.
728 This sets the actual hard register used for the frame pointer
729 to the location of the function's incoming static chain info.
730 The non-local goto handler will then adjust it to contain the
731 proper value and reload the argument pointer, if needed. */
732 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
734 /* We have now loaded the frame pointer hardware register with
735 the address of that corresponds to the start of the virtual
736 stack vars. So replace virtual_stack_vars_rtx in all
737 addresses we use with stack_pointer_rtx. */
739 /* Get addr of containing function's current nonlocal goto handler,
740 which will do any cleanups and then jump to the label. */
741 addr = copy_rtx (p->nonlocal_goto_handler_slot);
742 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
743 hard_frame_pointer_rtx));
745 /* Restore the stack pointer. Note this uses fp just restored. */
746 addr = p->nonlocal_goto_stack_level;
748 addr = replace_rtx (copy_rtx (addr),
749 virtual_stack_vars_rtx,
750 hard_frame_pointer_rtx);
752 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
754 /* Put in the static chain register the nonlocal label address. */
755 emit_move_insn (static_chain_rtx, label_ref);
756 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
758 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
759 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
760 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
761 emit_indirect_jump (temp);
765 expand_goto_internal (label, label_rtx (label), NULL_RTX);
768 /* Generate RTL code for a `goto' statement with target label BODY.
769 LABEL should be a LABEL_REF.
770 LAST_INSN, if non-0, is the rtx we should consider as the last
771 insn emitted (for the purposes of cleaning up a return). */
774 expand_goto_internal (body, label, last_insn)
779 struct nesting *block;
782 /* NOTICE! If a bytecode instruction other than `jump' is needed,
783 then the caller has to call bc_expand_goto_internal()
784 directly. This is rather an exceptional case, and there aren't
785 that many places where this is necessary. */
788 expand_goto_internal (body, label, last_insn);
792 if (GET_CODE (label) != CODE_LABEL)
795 /* If label has already been defined, we can tell now
796 whether and how we must alter the stack level. */
798 if (PREV_INSN (label) != 0)
800 /* Find the innermost pending block that contains the label.
801 (Check containment by comparing insn-uids.)
802 Then restore the outermost stack level within that block,
803 and do cleanups of all blocks contained in it. */
804 for (block = block_stack; block; block = block->next)
806 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
808 if (block->data.block.stack_level != 0)
809 stack_level = block->data.block.stack_level;
810 /* Execute the cleanups for blocks we are exiting. */
811 if (block->data.block.cleanups != 0)
813 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
814 do_pending_stack_adjust ();
820 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
821 the stack pointer. This one should be deleted as dead by flow. */
822 clear_pending_stack_adjust ();
823 do_pending_stack_adjust ();
824 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
827 if (body != 0 && DECL_TOO_LATE (body))
828 error ("jump to `%s' invalidly jumps into binding contour",
829 IDENTIFIER_POINTER (DECL_NAME (body)));
831 /* Label not yet defined: may need to put this goto
832 on the fixup list. */
833 else if (! expand_fixup (body, label, last_insn))
835 /* No fixup needed. Record that the label is the target
836 of at least one goto that has no fixup. */
838 TREE_ADDRESSABLE (body) = 1;
844 /* Generate a jump with OPCODE to the given bytecode LABEL which is
845 found within BODY. */
848 bc_expand_goto_internal (opcode, label, body)
849 enum bytecode_opcode opcode;
850 struct bc_label *label;
853 struct nesting *block;
854 int stack_level = -1;
856 /* If the label is defined, adjust the stack as necessary.
857 If it's not defined, we have to push the reference on the
863 /* Find the innermost pending block that contains the label.
864 (Check containment by comparing bytecode uids.) Then restore the
865 outermost stack level within that block. */
867 for (block = block_stack; block; block = block->next)
869 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
871 if (block->data.block.bc_stack_level)
872 stack_level = block->data.block.bc_stack_level;
874 /* Execute the cleanups for blocks we are exiting. */
875 if (block->data.block.cleanups != 0)
877 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
878 do_pending_stack_adjust ();
882 /* Restore the stack level. If we need to adjust the stack, we
883 must do so after the jump, since the jump may depend on
884 what's on the stack. Thus, any stack-modifying conditional
885 jumps (these are the only ones that rely on what's on the
886 stack) go into the fixup list. */
889 && stack_depth != stack_level
892 bc_expand_fixup (opcode, label, stack_level);
895 if (stack_level >= 0)
896 bc_adjust_stack (stack_depth - stack_level);
898 if (body && DECL_BIT_FIELD (body))
899 error ("jump to `%s' invalidly jumps into binding contour",
900 IDENTIFIER_POINTER (DECL_NAME (body)));
902 /* Emit immediate jump */
903 bc_emit_bytecode (opcode);
904 bc_emit_bytecode_labelref (label);
906 #ifdef DEBUG_PRINT_CODE
907 fputc ('\n', stderr);
912 /* Put goto in the fixup list */
913 bc_expand_fixup (opcode, label, stack_level);
916 /* Generate if necessary a fixup for a goto
917 whose target label in tree structure (if any) is TREE_LABEL
918 and whose target in rtl is RTL_LABEL.
920 If LAST_INSN is nonzero, we pretend that the jump appears
921 after insn LAST_INSN instead of at the current point in the insn stream.
923 The fixup will be used later to insert insns just before the goto.
924 Those insns will restore the stack level as appropriate for the
925 target label, and will (in the case of C++) also invoke any object
926 destructors which have to be invoked when we exit the scopes which
927 are exited by the goto.
929 Value is nonzero if a fixup is made. */
932 expand_fixup (tree_label, rtl_label, last_insn)
937 struct nesting *block, *end_block;
939 /* See if we can recognize which block the label will be output in.
940 This is possible in some very common cases.
941 If we succeed, set END_BLOCK to that block.
942 Otherwise, set it to 0. */
945 && (rtl_label == cond_stack->data.cond.endif_label
946 || rtl_label == cond_stack->data.cond.next_label))
947 end_block = cond_stack;
948 /* If we are in a loop, recognize certain labels which
949 are likely targets. This reduces the number of fixups
950 we need to create. */
952 && (rtl_label == loop_stack->data.loop.start_label
953 || rtl_label == loop_stack->data.loop.end_label
954 || rtl_label == loop_stack->data.loop.continue_label))
955 end_block = loop_stack;
959 /* Now set END_BLOCK to the binding level to which we will return. */
963 struct nesting *next_block = end_block->all;
966 /* First see if the END_BLOCK is inside the innermost binding level.
967 If so, then no cleanups or stack levels are relevant. */
968 while (next_block && next_block != block)
969 next_block = next_block->all;
974 /* Otherwise, set END_BLOCK to the innermost binding level
975 which is outside the relevant control-structure nesting. */
976 next_block = block_stack->next;
977 for (block = block_stack; block != end_block; block = block->all)
978 if (block == next_block)
979 next_block = next_block->next;
980 end_block = next_block;
983 /* Does any containing block have a stack level or cleanups?
984 If not, no fixup is needed, and that is the normal case
985 (the only case, for standard C). */
986 for (block = block_stack; block != end_block; block = block->next)
987 if (block->data.block.stack_level != 0
988 || block->data.block.cleanups != 0)
991 if (block != end_block)
993 /* Ok, a fixup is needed. Add a fixup to the list of such. */
994 struct goto_fixup *fixup
995 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
996 /* In case an old stack level is restored, make sure that comes
997 after any pending stack adjust. */
998 /* ?? If the fixup isn't to come at the present position,
999 doing the stack adjust here isn't useful. Doing it with our
1000 settings at that location isn't useful either. Let's hope
1003 do_pending_stack_adjust ();
1004 fixup->target = tree_label;
1005 fixup->target_rtl = rtl_label;
1007 /* Create a BLOCK node and a corresponding matched set of
1008 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1009 this point. The notes will encapsulate any and all fixup
1010 code which we might later insert at this point in the insn
1011 stream. Also, the BLOCK node will be the parent (i.e. the
1012 `SUPERBLOCK') of any other BLOCK nodes which we might create
1013 later on when we are expanding the fixup code. */
1016 register rtx original_before_jump
1017 = last_insn ? last_insn : get_last_insn ();
1021 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1022 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1023 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1025 emit_insns_after (fixup->before_jump, original_before_jump);
1028 fixup->block_start_count = block_start_count;
1029 fixup->stack_level = 0;
1030 fixup->cleanup_list_list
1031 = (((block->data.block.outer_cleanups
1033 && block->data.block.outer_cleanups != empty_cleanup_list
1036 || block->data.block.cleanups)
1037 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1038 block->data.block.outer_cleanups)
1040 fixup->next = goto_fixup_chain;
1041 goto_fixup_chain = fixup;
1048 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1049 Make the fixup restore the stack level to STACK_LEVEL. */
1052 bc_expand_fixup (opcode, label, stack_level)
1053 enum bytecode_opcode opcode;
1054 struct bc_label *label;
1057 struct goto_fixup *fixup
1058 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1060 fixup->label = bc_get_bytecode_label ();
1061 fixup->bc_target = label;
1062 fixup->bc_stack_level = stack_level;
1063 fixup->bc_handled = FALSE;
1065 fixup->next = goto_fixup_chain;
1066 goto_fixup_chain = fixup;
1068 /* Insert a jump to the fixup code */
1069 bc_emit_bytecode (opcode);
1070 bc_emit_bytecode_labelref (fixup->label);
1072 #ifdef DEBUG_PRINT_CODE
1073 fputc ('\n', stderr);
1077 /* Expand any needed fixups in the outputmost binding level of the
1078 function. FIRST_INSN is the first insn in the function. */
1081 expand_fixups (first_insn)
1084 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1087 /* When exiting a binding contour, process all pending gotos requiring fixups.
1088 THISBLOCK is the structure that describes the block being exited.
1089 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1090 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1091 FIRST_INSN is the insn that began this contour.
1093 Gotos that jump out of this contour must restore the
1094 stack level and do the cleanups before actually jumping.
1096 DONT_JUMP_IN nonzero means report error there is a jump into this
1097 contour from before the beginning of the contour.
1098 This is also done if STACK_LEVEL is nonzero. */
1101 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1102 struct nesting *thisblock;
1108 register struct goto_fixup *f, *prev;
1110 if (output_bytecode)
1112 /* ??? The second arg is the bc stack level, which is not the same
1113 as STACK_LEVEL. I have no idea what should go here, so I'll
1115 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1119 /* F is the fixup we are considering; PREV is the previous one. */
1120 /* We run this loop in two passes so that cleanups of exited blocks
1121 are run first, and blocks that are exited are marked so
1124 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1126 /* Test for a fixup that is inactive because it is already handled. */
1127 if (f->before_jump == 0)
1129 /* Delete inactive fixup from the chain, if that is easy to do. */
1131 prev->next = f->next;
1133 /* Has this fixup's target label been defined?
1134 If so, we can finalize it. */
1135 else if (PREV_INSN (f->target_rtl) != 0)
1137 register rtx cleanup_insns;
1139 /* Get the first non-label after the label
1140 this goto jumps to. If that's before this scope begins,
1141 we don't have a jump into the scope. */
1142 rtx after_label = f->target_rtl;
1143 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1144 after_label = NEXT_INSN (after_label);
1146 /* If this fixup jumped into this contour from before the beginning
1147 of this contour, report an error. */
1148 /* ??? Bug: this does not detect jumping in through intermediate
1149 blocks that have stack levels or cleanups.
1150 It detects only a problem with the innermost block
1151 around the label. */
1153 && (dont_jump_in || stack_level || cleanup_list)
1154 /* If AFTER_LABEL is 0, it means the jump goes to the end
1155 of the rtl, which means it jumps into this scope. */
1156 && (after_label == 0
1157 || INSN_UID (first_insn) < INSN_UID (after_label))
1158 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1159 && ! DECL_REGISTER (f->target))
1161 error_with_decl (f->target,
1162 "label `%s' used before containing binding contour");
1163 /* Prevent multiple errors for one label. */
1164 DECL_REGISTER (f->target) = 1;
1167 /* We will expand the cleanups into a sequence of their own and
1168 then later on we will attach this new sequence to the insn
1169 stream just ahead of the actual jump insn. */
1173 /* Temporarily restore the lexical context where we will
1174 logically be inserting the fixup code. We do this for the
1175 sake of getting the debugging information right. */
1178 set_block (f->context);
1180 /* Expand the cleanups for blocks this jump exits. */
1181 if (f->cleanup_list_list)
1184 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1185 /* Marked elements correspond to blocks that have been closed.
1186 Do their cleanups. */
1187 if (TREE_ADDRESSABLE (lists)
1188 && TREE_VALUE (lists) != 0)
1190 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1191 /* Pop any pushes done in the cleanups,
1192 in case function is about to return. */
1193 do_pending_stack_adjust ();
1197 /* Restore stack level for the biggest contour that this
1198 jump jumps out of. */
1200 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1202 /* Finish up the sequence containing the insns which implement the
1203 necessary cleanups, and then attach that whole sequence to the
1204 insn stream just ahead of the actual jump insn. Attaching it
1205 at that point insures that any cleanups which are in fact
1206 implicit C++ object destructions (which must be executed upon
1207 leaving the block) appear (to the debugger) to be taking place
1208 in an area of the generated code where the object(s) being
1209 destructed are still "in scope". */
1211 cleanup_insns = get_insns ();
1215 emit_insns_after (cleanup_insns, f->before_jump);
1222 /* For any still-undefined labels, do the cleanups for this block now.
1223 We must do this now since items in the cleanup list may go out
1224 of scope when the block ends. */
1225 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1226 if (f->before_jump != 0
1227 && PREV_INSN (f->target_rtl) == 0
1228 /* Label has still not appeared. If we are exiting a block with
1229 a stack level to restore, that started before the fixup,
1230 mark this stack level as needing restoration
1231 when the fixup is later finalized. */
1233 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1234 means the label is undefined. That's erroneous, but possible. */
1235 && (thisblock->data.block.block_start_count
1236 <= f->block_start_count))
1238 tree lists = f->cleanup_list_list;
1241 for (; lists; lists = TREE_CHAIN (lists))
1242 /* If the following elt. corresponds to our containing block
1243 then the elt. must be for this block. */
1244 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1248 set_block (f->context);
1249 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1250 do_pending_stack_adjust ();
1251 cleanup_insns = get_insns ();
1255 = emit_insns_after (cleanup_insns, f->before_jump);
1257 TREE_VALUE (lists) = 0;
1261 f->stack_level = stack_level;
1266 /* When exiting a binding contour, process all pending gotos requiring fixups.
1267 Note: STACK_DEPTH is not altered.
1269 The arguments are currently not used in the bytecode compiler, but we may
1270 need them one day for languages other than C.
1272 THISBLOCK is the structure that describes the block being exited.
1273 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1274 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1275 FIRST_INSN is the insn that began this contour.
1277 Gotos that jump out of this contour must restore the
1278 stack level and do the cleanups before actually jumping.
1280 DONT_JUMP_IN nonzero means report error there is a jump into this
1281 contour from before the beginning of the contour.
1282 This is also done if STACK_LEVEL is nonzero. */
1285 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1286 struct nesting *thisblock;
1292 register struct goto_fixup *f, *prev;
1293 int saved_stack_depth;
1295 /* F is the fixup we are considering; PREV is the previous one. */
1297 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1299 /* Test for a fixup that is inactive because it is already handled. */
1300 if (f->before_jump == 0)
1302 /* Delete inactive fixup from the chain, if that is easy to do. */
1304 prev->next = f->next;
1307 /* Emit code to restore the stack and continue */
1308 bc_emit_bytecode_labeldef (f->label);
1310 /* Save stack_depth across call, since bc_adjust_stack () will alter
1311 the perceived stack depth via the instructions generated. */
1313 if (f->bc_stack_level >= 0)
1315 saved_stack_depth = stack_depth;
1316 bc_adjust_stack (stack_depth - f->bc_stack_level);
1317 stack_depth = saved_stack_depth;
1320 bc_emit_bytecode (jump);
1321 bc_emit_bytecode_labelref (f->bc_target);
1323 #ifdef DEBUG_PRINT_CODE
1324 fputc ('\n', stderr);
1328 goto_fixup_chain = NULL;
1331 /* Generate RTL for an asm statement (explicit assembler code).
1332 BODY is a STRING_CST node containing the assembler code text,
1333 or an ADDR_EXPR containing a STRING_CST. */
1339 if (output_bytecode)
1341 error ("`asm' is invalid when generating bytecode");
1345 if (TREE_CODE (body) == ADDR_EXPR)
1346 body = TREE_OPERAND (body, 0);
1348 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1349 TREE_STRING_POINTER (body)));
1353 /* Generate RTL for an asm statement with arguments.
1354 STRING is the instruction template.
1355 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1356 Each output or input has an expression in the TREE_VALUE and
1357 a constraint-string in the TREE_PURPOSE.
1358 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1359 that is clobbered by this insn.
1361 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1362 Some elements of OUTPUTS may be replaced with trees representing temporary
1363 values. The caller should copy those temporary values to the originally
1366 VOL nonzero means the insn is volatile; don't optimize it. */
1369 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1370 tree string, outputs, inputs, clobbers;
1375 rtvec argvec, constraints;
1377 int ninputs = list_length (inputs);
1378 int noutputs = list_length (outputs);
1382 /* Vector of RTX's of evaluated output operands. */
1383 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1384 /* The insn we have emitted. */
1387 if (output_bytecode)
1389 error ("`asm' is invalid when generating bytecode");
1393 /* Count the number of meaningful clobbered registers, ignoring what
1394 we would ignore later. */
1396 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1398 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1399 i = decode_reg_name (regname);
1400 if (i >= 0 || i == -4)
1403 error ("unknown register name `%s' in `asm'", regname);
1408 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1410 tree val = TREE_VALUE (tail);
1411 tree type = TREE_TYPE (val);
1416 /* If there's an erroneous arg, emit no insn. */
1417 if (TREE_TYPE (val) == error_mark_node)
1420 /* Make sure constraint has `=' and does not have `+'. */
1423 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1425 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1427 error ("output operand constraint contains `+'");
1430 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=')
1435 error ("output operand constraint lacks `='");
1439 /* If an output operand is not a decl or indirect ref,
1440 make a temporary to act as an intermediate. Make the asm insn
1441 write into that, then our caller will copy it to the real output
1442 operand. Likewise for promoted variables. */
1444 if (TREE_CODE (val) == INDIRECT_REF
1445 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1446 && ! (GET_CODE (DECL_RTL (val)) == REG
1447 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
1448 output_rtx[i] = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1451 if (TYPE_MODE (type) == BLKmode)
1453 output_rtx[i] = assign_stack_temp (BLKmode,
1454 int_size_in_bytes (type), 0);
1455 MEM_IN_STRUCT_P (output_rtx[i]) = AGGREGATE_TYPE_P (type);
1458 output_rtx[i] = gen_reg_rtx (TYPE_MODE (type));
1460 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1464 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1466 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1470 /* Make vectors for the expression-rtx and constraint strings. */
1472 argvec = rtvec_alloc (ninputs);
1473 constraints = rtvec_alloc (ninputs);
1475 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1476 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1478 MEM_VOLATILE_P (body) = vol;
1480 /* Eval the inputs and put them into ARGVEC.
1481 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1484 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1488 /* If there's an erroneous arg, emit no insn,
1489 because the ASM_INPUT would get VOIDmode
1490 and that could cause a crash in reload. */
1491 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1493 if (TREE_PURPOSE (tail) == NULL_TREE)
1495 error ("hard register `%s' listed as input operand to `asm'",
1496 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1500 /* Make sure constraint has neither `=' nor `+'. */
1502 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1503 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '='
1504 || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1506 error ("input operand constraint contains `%c'",
1507 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1511 XVECEXP (body, 3, i) /* argvec */
1512 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1513 if (CONSTANT_P (XVECEXP (body, 3, i))
1514 && ! general_operand (XVECEXP (body, 3, i),
1515 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1516 XVECEXP (body, 3, i)
1517 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1518 XVECEXP (body, 3, i));
1519 XVECEXP (body, 4, i) /* constraints */
1520 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1521 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1525 /* Protect all the operands from the queue,
1526 now that they have all been evaluated. */
1528 for (i = 0; i < ninputs; i++)
1529 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1531 for (i = 0; i < noutputs; i++)
1532 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1534 /* Now, for each output, construct an rtx
1535 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1536 ARGVEC CONSTRAINTS))
1537 If there is more than one, put them inside a PARALLEL. */
1539 if (noutputs == 1 && nclobbers == 0)
1541 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1542 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1544 else if (noutputs == 0 && nclobbers == 0)
1546 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1547 insn = emit_insn (body);
1553 if (num == 0) num = 1;
1554 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1556 /* For each output operand, store a SET. */
1558 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1560 XVECEXP (body, 0, i)
1561 = gen_rtx (SET, VOIDmode,
1563 gen_rtx (ASM_OPERANDS, VOIDmode,
1564 TREE_STRING_POINTER (string),
1565 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1566 i, argvec, constraints,
1568 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1571 /* If there are no outputs (but there are some clobbers)
1572 store the bare ASM_OPERANDS into the PARALLEL. */
1575 XVECEXP (body, 0, i++) = obody;
1577 /* Store (clobber REG) for each clobbered register specified. */
1579 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1581 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1582 int j = decode_reg_name (regname);
1586 if (j == -3) /* `cc', which is not a register */
1589 if (j == -4) /* `memory', don't cache memory across asm */
1591 XVECEXP (body, 0, i++)
1592 = gen_rtx (CLOBBER, VOIDmode,
1593 gen_rtx (MEM, BLKmode,
1594 gen_rtx (SCRATCH, VOIDmode, 0)));
1598 /* Ignore unknown register, error already signalled. */
1602 /* Use QImode since that's guaranteed to clobber just one reg. */
1603 XVECEXP (body, 0, i++)
1604 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1607 insn = emit_insn (body);
1613 /* Generate RTL to evaluate the expression EXP
1614 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1617 expand_expr_stmt (exp)
1620 if (output_bytecode)
1622 int org_stack_depth = stack_depth;
1624 bc_expand_expr (exp);
1626 /* Restore stack depth */
1627 if (stack_depth < org_stack_depth)
1630 bc_emit_instruction (drop);
1632 last_expr_type = TREE_TYPE (exp);
1636 /* If -W, warn about statements with no side effects,
1637 except for an explicit cast to void (e.g. for assert()), and
1638 except inside a ({...}) where they may be useful. */
1639 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1641 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1642 && !(TREE_CODE (exp) == CONVERT_EXPR
1643 && TREE_TYPE (exp) == void_type_node))
1644 warning_with_file_and_line (emit_filename, emit_lineno,
1645 "statement with no effect");
1646 else if (warn_unused)
1647 warn_if_unused_value (exp);
1650 /* If EXP is of function type and we are expanding statements for
1651 value, convert it to pointer-to-function. */
1652 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1653 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1655 last_expr_type = TREE_TYPE (exp);
1656 if (! flag_syntax_only)
1657 last_expr_value = expand_expr (exp,
1658 (expr_stmts_for_value
1659 ? NULL_RTX : const0_rtx),
1662 /* If all we do is reference a volatile value in memory,
1663 copy it to a register to be sure it is actually touched. */
1664 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1665 && TREE_THIS_VOLATILE (exp))
1667 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1669 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1670 copy_to_reg (last_expr_value);
1673 rtx lab = gen_label_rtx ();
1675 /* Compare the value with itself to reference it. */
1676 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1677 expand_expr (TYPE_SIZE (last_expr_type),
1678 NULL_RTX, VOIDmode, 0),
1680 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1681 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1686 /* If this expression is part of a ({...}) and is in memory, we may have
1687 to preserve temporaries. */
1688 preserve_temp_slots (last_expr_value);
1690 /* Free any temporaries used to evaluate this expression. Any temporary
1691 used as a result of this expression will already have been preserved
1698 /* Warn if EXP contains any computations whose results are not used.
1699 Return 1 if a warning is printed; 0 otherwise. */
1702 warn_if_unused_value (exp)
1705 if (TREE_USED (exp))
1708 switch (TREE_CODE (exp))
1710 case PREINCREMENT_EXPR:
1711 case POSTINCREMENT_EXPR:
1712 case PREDECREMENT_EXPR:
1713 case POSTDECREMENT_EXPR:
1718 case METHOD_CALL_EXPR:
1720 case WITH_CLEANUP_EXPR:
1722 /* We don't warn about COND_EXPR because it may be a useful
1723 construct if either arm contains a side effect. */
1728 /* For a binding, warn if no side effect within it. */
1729 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1732 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1734 case TRUTH_ORIF_EXPR:
1735 case TRUTH_ANDIF_EXPR:
1736 /* In && or ||, warn if 2nd operand has no side effect. */
1737 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1740 if (TREE_NO_UNUSED_WARNING (exp))
1742 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1744 /* Let people do `(foo (), 0)' without a warning. */
1745 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1747 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1751 case NON_LVALUE_EXPR:
1752 /* Don't warn about values cast to void. */
1753 if (TREE_TYPE (exp) == void_type_node)
1755 /* Don't warn about conversions not explicit in the user's program. */
1756 if (TREE_NO_UNUSED_WARNING (exp))
1758 /* Assignment to a cast usually results in a cast of a modify.
1759 Don't complain about that. There can be an arbitrary number of
1760 casts before the modify, so we must loop until we find the first
1761 non-cast expression and then test to see if that is a modify. */
1763 tree tem = TREE_OPERAND (exp, 0);
1765 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1766 tem = TREE_OPERAND (tem, 0);
1768 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1769 || TREE_CODE (tem) == CALL_EXPR)
1775 /* Don't warn about automatic dereferencing of references, since
1776 the user cannot control it. */
1777 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1778 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1779 /* ... fall through ... */
1782 /* Referencing a volatile value is a side effect, so don't warn. */
1783 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1784 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1785 && TREE_THIS_VOLATILE (exp))
1788 warning_with_file_and_line (emit_filename, emit_lineno,
1789 "value computed is not used");
1794 /* Clear out the memory of the last expression evaluated. */
1802 /* Begin a statement which will return a value.
1803 Return the RTL_EXPR for this statement expr.
1804 The caller must save that value and pass it to expand_end_stmt_expr. */
1807 expand_start_stmt_expr ()
1812 /* When generating bytecode just note down the stack depth */
1813 if (output_bytecode)
1814 return (build_int_2 (stack_depth, 0));
1816 /* Make the RTL_EXPR node temporary, not momentary,
1817 so that rtl_expr_chain doesn't become garbage. */
1818 momentary = suspend_momentary ();
1819 t = make_node (RTL_EXPR);
1820 resume_momentary (momentary);
1821 start_sequence_for_rtl_expr (t);
1823 expr_stmts_for_value++;
1827 /* Restore the previous state at the end of a statement that returns a value.
1828 Returns a tree node representing the statement's value and the
1829 insns to compute the value.
1831 The nodes of that expression have been freed by now, so we cannot use them.
1832 But we don't want to do that anyway; the expression has already been
1833 evaluated and now we just want to use the value. So generate a RTL_EXPR
1834 with the proper type and RTL value.
1836 If the last substatement was not an expression,
1837 return something with type `void'. */
1840 expand_end_stmt_expr (t)
1843 if (output_bytecode)
1849 /* At this point, all expressions have been evaluated in order.
1850 However, all expression values have been popped when evaluated,
1851 which means we have to recover the last expression value. This is
1852 the last value removed by means of a `drop' instruction. Instead
1853 of adding code to inhibit dropping the last expression value, it
1854 is here recovered by undoing the `drop'. Since `drop' is
1855 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1858 bc_adjust_stack (-1);
1860 if (!last_expr_type)
1861 last_expr_type = void_type_node;
1863 t = make_node (RTL_EXPR);
1864 TREE_TYPE (t) = last_expr_type;
1865 RTL_EXPR_RTL (t) = NULL;
1866 RTL_EXPR_SEQUENCE (t) = NULL;
1868 /* Don't consider deleting this expr or containing exprs at tree level. */
1869 TREE_THIS_VOLATILE (t) = 1;
1877 if (last_expr_type == 0)
1879 last_expr_type = void_type_node;
1880 last_expr_value = const0_rtx;
1882 else if (last_expr_value == 0)
1883 /* There are some cases where this can happen, such as when the
1884 statement is void type. */
1885 last_expr_value = const0_rtx;
1886 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1887 /* Remove any possible QUEUED. */
1888 last_expr_value = protect_from_queue (last_expr_value, 0);
1892 TREE_TYPE (t) = last_expr_type;
1893 RTL_EXPR_RTL (t) = last_expr_value;
1894 RTL_EXPR_SEQUENCE (t) = get_insns ();
1896 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1900 /* Don't consider deleting this expr or containing exprs at tree level. */
1901 TREE_SIDE_EFFECTS (t) = 1;
1902 /* Propagate volatility of the actual RTL expr. */
1903 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1906 expr_stmts_for_value--;
1911 /* Generate RTL for the start of an if-then. COND is the expression
1912 whose truth should be tested.
1914 If EXITFLAG is nonzero, this conditional is visible to
1915 `exit_something'. */
1918 expand_start_cond (cond, exitflag)
1922 struct nesting *thiscond = ALLOC_NESTING ();
1924 /* Make an entry on cond_stack for the cond we are entering. */
1926 thiscond->next = cond_stack;
1927 thiscond->all = nesting_stack;
1928 thiscond->depth = ++nesting_depth;
1929 thiscond->data.cond.next_label = gen_label_rtx ();
1930 /* Before we encounter an `else', we don't need a separate exit label
1931 unless there are supposed to be exit statements
1932 to exit this conditional. */
1933 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1934 thiscond->data.cond.endif_label = thiscond->exit_label;
1935 cond_stack = thiscond;
1936 nesting_stack = thiscond;
1938 if (output_bytecode)
1939 bc_expand_start_cond (cond, exitflag);
1941 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1944 /* Generate RTL between then-clause and the elseif-clause
1945 of an if-then-elseif-.... */
1948 expand_start_elseif (cond)
1951 if (cond_stack->data.cond.endif_label == 0)
1952 cond_stack->data.cond.endif_label = gen_label_rtx ();
1953 emit_jump (cond_stack->data.cond.endif_label);
1954 emit_label (cond_stack->data.cond.next_label);
1955 cond_stack->data.cond.next_label = gen_label_rtx ();
1956 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1959 /* Generate RTL between the then-clause and the else-clause
1960 of an if-then-else. */
1963 expand_start_else ()
1965 if (cond_stack->data.cond.endif_label == 0)
1966 cond_stack->data.cond.endif_label = gen_label_rtx ();
1968 if (output_bytecode)
1970 bc_expand_start_else ();
1974 emit_jump (cond_stack->data.cond.endif_label);
1975 emit_label (cond_stack->data.cond.next_label);
1976 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
1979 /* After calling expand_start_else, turn this "else" into an "else if"
1980 by providing another condition. */
1983 expand_elseif (cond)
1986 cond_stack->data.cond.next_label = gen_label_rtx ();
1987 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1990 /* Generate RTL for the end of an if-then.
1991 Pop the record for it off of cond_stack. */
1996 struct nesting *thiscond = cond_stack;
1998 if (output_bytecode)
1999 bc_expand_end_cond ();
2002 do_pending_stack_adjust ();
2003 if (thiscond->data.cond.next_label)
2004 emit_label (thiscond->data.cond.next_label);
2005 if (thiscond->data.cond.endif_label)
2006 emit_label (thiscond->data.cond.endif_label);
2009 POPSTACK (cond_stack);
2014 /* Generate code for the start of an if-then. COND is the expression
2015 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2016 is to be visible to exit_something. It is assumed that the caller
2017 has pushed the previous context on the cond stack. */
2020 bc_expand_start_cond (cond, exitflag)
2024 struct nesting *thiscond = cond_stack;
2026 thiscond->data.case_stmt.nominal_type = cond;
2028 thiscond->exit_label = gen_label_rtx ();
2029 bc_expand_expr (cond);
2030 bc_emit_bytecode (xjumpifnot);
2031 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2033 #ifdef DEBUG_PRINT_CODE
2034 fputc ('\n', stderr);
2038 /* Generate the label for the end of an if with
2042 bc_expand_end_cond ()
2044 struct nesting *thiscond = cond_stack;
2046 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2049 /* Generate code for the start of the else- clause of
2053 bc_expand_start_else ()
2055 struct nesting *thiscond = cond_stack;
2057 thiscond->data.cond.endif_label = thiscond->exit_label;
2058 thiscond->exit_label = gen_label_rtx ();
2059 bc_emit_bytecode (jump);
2060 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2062 #ifdef DEBUG_PRINT_CODE
2063 fputc ('\n', stderr);
2066 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2069 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2070 loop should be exited by `exit_something'. This is a loop for which
2071 `expand_continue' will jump to the top of the loop.
2073 Make an entry on loop_stack to record the labels associated with
2077 expand_start_loop (exit_flag)
2080 register struct nesting *thisloop = ALLOC_NESTING ();
2082 /* Make an entry on loop_stack for the loop we are entering. */
2084 thisloop->next = loop_stack;
2085 thisloop->all = nesting_stack;
2086 thisloop->depth = ++nesting_depth;
2087 thisloop->data.loop.start_label = gen_label_rtx ();
2088 thisloop->data.loop.end_label = gen_label_rtx ();
2089 thisloop->data.loop.alt_end_label = 0;
2090 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2091 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2092 loop_stack = thisloop;
2093 nesting_stack = thisloop;
2095 if (output_bytecode)
2097 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2101 do_pending_stack_adjust ();
2103 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2104 emit_label (thisloop->data.loop.start_label);
2109 /* Like expand_start_loop but for a loop where the continuation point
2110 (for expand_continue_loop) will be specified explicitly. */
2113 expand_start_loop_continue_elsewhere (exit_flag)
2116 struct nesting *thisloop = expand_start_loop (exit_flag);
2117 loop_stack->data.loop.continue_label = gen_label_rtx ();
2121 /* Specify the continuation point for a loop started with
2122 expand_start_loop_continue_elsewhere.
2123 Use this at the point in the code to which a continue statement
2127 expand_loop_continue_here ()
2129 if (output_bytecode)
2131 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2134 do_pending_stack_adjust ();
2135 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2136 emit_label (loop_stack->data.loop.continue_label);
2142 bc_expand_end_loop ()
2144 struct nesting *thisloop = loop_stack;
2146 bc_emit_bytecode (jump);
2147 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2149 #ifdef DEBUG_PRINT_CODE
2150 fputc ('\n', stderr);
2153 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2154 POPSTACK (loop_stack);
2159 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2160 Pop the block off of loop_stack. */
2166 register rtx start_label;
2167 rtx last_test_insn = 0;
2170 if (output_bytecode)
2172 bc_expand_end_loop ();
2176 insn = get_last_insn ();
2177 start_label = loop_stack->data.loop.start_label;
2179 /* Mark the continue-point at the top of the loop if none elsewhere. */
2180 if (start_label == loop_stack->data.loop.continue_label)
2181 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2183 do_pending_stack_adjust ();
2185 /* If optimizing, perhaps reorder the loop. If the loop
2186 starts with a conditional exit, roll that to the end
2187 where it will optimize together with the jump back.
2189 We look for the last conditional branch to the exit that we encounter
2190 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2191 branch to the exit first, use it.
2193 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2194 because moving them is not valid. */
2198 ! (GET_CODE (insn) == JUMP_INSN
2199 && GET_CODE (PATTERN (insn)) == SET
2200 && SET_DEST (PATTERN (insn)) == pc_rtx
2201 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2203 /* Scan insns from the top of the loop looking for a qualified
2204 conditional exit. */
2205 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2206 insn = NEXT_INSN (insn))
2208 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2211 if (GET_CODE (insn) == NOTE
2212 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2213 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2216 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2219 if (last_test_insn && num_insns > 30)
2222 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2223 && SET_DEST (PATTERN (insn)) == pc_rtx
2224 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2225 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2226 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2227 == loop_stack->data.loop.end_label)
2228 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2229 == loop_stack->data.loop.alt_end_label)))
2230 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2231 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2232 == loop_stack->data.loop.end_label)
2233 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2234 == loop_stack->data.loop.alt_end_label)))))
2235 last_test_insn = insn;
2237 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2238 && GET_CODE (PATTERN (insn)) == SET
2239 && SET_DEST (PATTERN (insn)) == pc_rtx
2240 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2241 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2242 == loop_stack->data.loop.end_label)
2243 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2244 == loop_stack->data.loop.alt_end_label)))
2245 /* Include BARRIER. */
2246 last_test_insn = NEXT_INSN (insn);
2249 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2251 /* We found one. Move everything from there up
2252 to the end of the loop, and add a jump into the loop
2253 to jump to there. */
2254 register rtx newstart_label = gen_label_rtx ();
2255 register rtx start_move = start_label;
2257 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2258 then we want to move this note also. */
2259 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2260 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2261 == NOTE_INSN_LOOP_CONT))
2262 start_move = PREV_INSN (start_move);
2264 emit_label_after (newstart_label, PREV_INSN (start_move));
2265 reorder_insns (start_move, last_test_insn, get_last_insn ());
2266 emit_jump_insn_after (gen_jump (start_label),
2267 PREV_INSN (newstart_label));
2268 emit_barrier_after (PREV_INSN (newstart_label));
2269 start_label = newstart_label;
2273 emit_jump (start_label);
2274 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2275 emit_label (loop_stack->data.loop.end_label);
2277 POPSTACK (loop_stack);
2282 /* Generate a jump to the current loop's continue-point.
2283 This is usually the top of the loop, but may be specified
2284 explicitly elsewhere. If not currently inside a loop,
2285 return 0 and do nothing; caller will print an error message. */
2288 expand_continue_loop (whichloop)
2289 struct nesting *whichloop;
2293 whichloop = loop_stack;
2296 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2301 /* Generate a jump to exit the current loop. If not currently inside a loop,
2302 return 0 and do nothing; caller will print an error message. */
2305 expand_exit_loop (whichloop)
2306 struct nesting *whichloop;
2310 whichloop = loop_stack;
2313 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2317 /* Generate a conditional jump to exit the current loop if COND
2318 evaluates to zero. If not currently inside a loop,
2319 return 0 and do nothing; caller will print an error message. */
2322 expand_exit_loop_if_false (whichloop, cond)
2323 struct nesting *whichloop;
2328 whichloop = loop_stack;
2331 if (output_bytecode)
2333 bc_expand_expr (cond);
2334 bc_expand_goto_internal (xjumpifnot,
2335 BYTECODE_BC_LABEL (whichloop->exit_label),
2340 /* In order to handle fixups, we actually create a conditional jump
2341 around a unconditional branch to exit the loop. If fixups are
2342 necessary, they go before the unconditional branch. */
2344 rtx label = gen_label_rtx ();
2347 do_jump (cond, NULL_RTX, label);
2348 last_insn = get_last_insn ();
2349 if (GET_CODE (last_insn) == CODE_LABEL)
2350 whichloop->data.loop.alt_end_label = last_insn;
2351 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2359 /* Return non-zero if we should preserve sub-expressions as separate
2360 pseudos. We never do so if we aren't optimizing. We always do so
2361 if -fexpensive-optimizations.
2363 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2364 the loop may still be a small one. */
2367 preserve_subexpressions_p ()
2371 if (flag_expensive_optimizations)
2374 if (optimize == 0 || loop_stack == 0)
2377 insn = get_last_insn_anywhere ();
2380 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2381 < n_non_fixed_regs * 3));
2385 /* Generate a jump to exit the current loop, conditional, binding contour
2386 or case statement. Not all such constructs are visible to this function,
2387 only those started with EXIT_FLAG nonzero. Individual languages use
2388 the EXIT_FLAG parameter to control which kinds of constructs you can
2391 If not currently inside anything that can be exited,
2392 return 0 and do nothing; caller will print an error message. */
2395 expand_exit_something ()
2399 for (n = nesting_stack; n; n = n->all)
2400 if (n->exit_label != 0)
2402 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2409 /* Generate RTL to return from the current function, with no value.
2410 (That is, we do not do anything about returning any value.) */
2413 expand_null_return ()
2415 struct nesting *block = block_stack;
2418 if (output_bytecode)
2420 bc_emit_instruction (ret);
2424 /* Does any pending block have cleanups? */
2426 while (block && block->data.block.cleanups == 0)
2427 block = block->next;
2429 /* If yes, use a goto to return, since that runs cleanups. */
2431 expand_null_return_1 (last_insn, block != 0);
2434 /* Generate RTL to return from the current function, with value VAL. */
2437 expand_value_return (val)
2440 struct nesting *block = block_stack;
2441 rtx last_insn = get_last_insn ();
2442 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2444 /* Copy the value to the return location
2445 unless it's already there. */
2447 if (return_reg != val)
2449 #ifdef PROMOTE_FUNCTION_RETURN
2450 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2451 int unsignedp = TREE_UNSIGNED (type);
2452 enum machine_mode mode
2453 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2456 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2457 convert_move (return_reg, val, unsignedp);
2460 emit_move_insn (return_reg, val);
2462 if (GET_CODE (return_reg) == REG
2463 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2464 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2466 /* Does any pending block have cleanups? */
2468 while (block && block->data.block.cleanups == 0)
2469 block = block->next;
2471 /* If yes, use a goto to return, since that runs cleanups.
2472 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2474 expand_null_return_1 (last_insn, block != 0);
2477 /* Output a return with no value. If LAST_INSN is nonzero,
2478 pretend that the return takes place after LAST_INSN.
2479 If USE_GOTO is nonzero then don't use a return instruction;
2480 go to the return label instead. This causes any cleanups
2481 of pending blocks to be executed normally. */
2484 expand_null_return_1 (last_insn, use_goto)
2488 rtx end_label = cleanup_label ? cleanup_label : return_label;
2490 clear_pending_stack_adjust ();
2491 do_pending_stack_adjust ();
2494 /* PCC-struct return always uses an epilogue. */
2495 if (current_function_returns_pcc_struct || use_goto)
2498 end_label = return_label = gen_label_rtx ();
2499 expand_goto_internal (NULL_TREE, end_label, last_insn);
2503 /* Otherwise output a simple return-insn if one is available,
2504 unless it won't do the job. */
2506 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2508 emit_jump_insn (gen_return ());
2514 /* Otherwise jump to the epilogue. */
2515 expand_goto_internal (NULL_TREE, end_label, last_insn);
2518 /* Generate RTL to evaluate the expression RETVAL and return it
2519 from the current function. */
2522 expand_return (retval)
2525 /* If there are any cleanups to be performed, then they will
2526 be inserted following LAST_INSN. It is desirable
2527 that the last_insn, for such purposes, should be the
2528 last insn before computing the return value. Otherwise, cleanups
2529 which call functions can clobber the return value. */
2530 /* ??? rms: I think that is erroneous, because in C++ it would
2531 run destructors on variables that might be used in the subsequent
2532 computation of the return value. */
2534 register rtx val = 0;
2538 struct nesting *block;
2540 /* Bytecode returns are quite simple, just leave the result on the
2541 arithmetic stack. */
2542 if (output_bytecode)
2544 bc_expand_expr (retval);
2545 bc_emit_instruction (ret);
2549 /* If function wants no value, give it none. */
2550 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2552 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2554 expand_null_return ();
2558 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2559 /* This is not sufficient. We also need to watch for cleanups of the
2560 expression we are about to expand. Unfortunately, we cannot know
2561 if it has cleanups until we expand it, and we want to change how we
2562 expand it depending upon if we need cleanups. We can't win. */
2564 cleanups = any_pending_cleanups (1);
2569 if (TREE_CODE (retval) == RESULT_DECL)
2570 retval_rhs = retval;
2571 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2572 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2573 retval_rhs = TREE_OPERAND (retval, 1);
2574 else if (TREE_TYPE (retval) == void_type_node)
2575 /* Recognize tail-recursive call to void function. */
2576 retval_rhs = retval;
2578 retval_rhs = NULL_TREE;
2580 /* Only use `last_insn' if there are cleanups which must be run. */
2581 if (cleanups || cleanup_label != 0)
2582 last_insn = get_last_insn ();
2584 /* Distribute return down conditional expr if either of the sides
2585 may involve tail recursion (see test below). This enhances the number
2586 of tail recursions we see. Don't do this always since it can produce
2587 sub-optimal code in some cases and we distribute assignments into
2588 conditional expressions when it would help. */
2590 if (optimize && retval_rhs != 0
2591 && frame_offset == 0
2592 && TREE_CODE (retval_rhs) == COND_EXPR
2593 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2594 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2596 rtx label = gen_label_rtx ();
2599 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2600 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2601 DECL_RESULT (current_function_decl),
2602 TREE_OPERAND (retval_rhs, 1));
2603 TREE_SIDE_EFFECTS (expr) = 1;
2604 expand_return (expr);
2607 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2608 DECL_RESULT (current_function_decl),
2609 TREE_OPERAND (retval_rhs, 2));
2610 TREE_SIDE_EFFECTS (expr) = 1;
2611 expand_return (expr);
2615 /* For tail-recursive call to current function,
2616 just jump back to the beginning.
2617 It's unsafe if any auto variable in this function
2618 has its address taken; for simplicity,
2619 require stack frame to be empty. */
2620 if (optimize && retval_rhs != 0
2621 && frame_offset == 0
2622 && TREE_CODE (retval_rhs) == CALL_EXPR
2623 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2624 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2625 /* Finish checking validity, and if valid emit code
2626 to set the argument variables for the new call. */
2627 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2628 DECL_ARGUMENTS (current_function_decl)))
2630 if (tail_recursion_label == 0)
2632 tail_recursion_label = gen_label_rtx ();
2633 emit_label_after (tail_recursion_label,
2634 tail_recursion_reentry);
2637 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2642 /* This optimization is safe if there are local cleanups
2643 because expand_null_return takes care of them.
2644 ??? I think it should also be safe when there is a cleanup label,
2645 because expand_null_return takes care of them, too.
2646 Any reason why not? */
2647 if (HAVE_return && cleanup_label == 0
2648 && ! current_function_returns_pcc_struct
2649 && BRANCH_COST <= 1)
2651 /* If this is return x == y; then generate
2652 if (x == y) return 1; else return 0;
2653 if we can do it with explicit return insns and
2654 branches are cheap. */
2656 switch (TREE_CODE (retval_rhs))
2664 case TRUTH_ANDIF_EXPR:
2665 case TRUTH_ORIF_EXPR:
2666 case TRUTH_AND_EXPR:
2668 case TRUTH_NOT_EXPR:
2669 case TRUTH_XOR_EXPR:
2670 op0 = gen_label_rtx ();
2671 jumpifnot (retval_rhs, op0);
2672 expand_value_return (const1_rtx);
2674 expand_value_return (const0_rtx);
2678 #endif /* HAVE_return */
2680 /* If the result is an aggregate that is being returned in one (or more)
2681 registers, load the registers here. The compiler currently can't handle
2682 copying a BLKmode value into registers. We could put this code in a
2683 more general area (for use by everyone instead of just function
2684 call/return), but until this feature is generally usable it is kept here
2685 (and in expand_call). The value must go into a pseudo in case there
2686 are cleanups that will clobber the real return register. */
2689 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2690 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2693 int big_endian_correction = 0;
2694 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2695 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2696 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2698 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2699 enum machine_mode tmpmode, result_reg_mode;
2701 /* Structures smaller than a word are aligned to the least significant
2702 byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we
2703 must skip the empty high order bytes when calculating the bit
2705 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
2706 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
2708 for (i = 0; i < n_regs; i++)
2710 rtx reg = gen_reg_rtx (word_mode);
2711 rtx word = operand_subword_force (result_val, i, BLKmode);
2712 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2715 result_pseudos[i] = reg;
2717 /* Clobber REG and move each partword into it. Ensure we don't
2718 go past the end of the structure. Note that the loop below
2719 works because we've already verified that padding and
2720 endianness are compatible. */
2721 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
2724 bitpos < BITS_PER_WORD && bytes > 0;
2725 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
2727 int xbitpos = bitpos + big_endian_correction;
2729 store_bit_field (reg, bitsize, xbitpos, word_mode,
2730 extract_bit_field (word, bitsize, bitpos, 1,
2731 NULL_RTX, word_mode,
2733 bitsize / BITS_PER_UNIT,
2735 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2739 /* Find the smallest integer mode large enough to hold the
2740 entire structure and use that mode instead of BLKmode
2741 on the USE insn for the return register. */
2742 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2743 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2744 tmpmode != MAX_MACHINE_MODE;
2745 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2747 /* Have we found a large enough mode? */
2748 if (GET_MODE_SIZE (tmpmode) >= bytes)
2752 /* No suitable mode found. */
2753 if (tmpmode == MAX_MACHINE_MODE)
2756 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2758 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2759 result_reg_mode = word_mode;
2761 result_reg_mode = tmpmode;
2762 result_reg = gen_reg_rtx (result_reg_mode);
2764 /* Now that the value is in pseudos, copy it to the result reg(s). */
2767 for (i = 0; i < n_regs; i++)
2768 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2771 if (tmpmode != result_reg_mode)
2772 result_reg = gen_lowpart (tmpmode, result_reg);
2774 expand_value_return (result_reg);
2778 && TREE_TYPE (retval_rhs) != void_type_node
2779 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2781 /* Calculate the return value into a pseudo reg. */
2782 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2784 /* All temporaries have now been used. */
2786 /* Return the calculated value, doing cleanups first. */
2787 expand_value_return (val);
2791 /* No cleanups or no hard reg used;
2792 calculate value into hard return reg. */
2793 expand_expr (retval, const0_rtx, VOIDmode, 0);
2796 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2800 /* Return 1 if the end of the generated RTX is not a barrier.
2801 This means code already compiled can drop through. */
2804 drop_through_at_end_p ()
2806 rtx insn = get_last_insn ();
2807 while (insn && GET_CODE (insn) == NOTE)
2808 insn = PREV_INSN (insn);
2809 return insn && GET_CODE (insn) != BARRIER;
2812 /* Emit code to alter this function's formal parms for a tail-recursive call.
2813 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2814 FORMALS is the chain of decls of formals.
2815 Return 1 if this can be done;
2816 otherwise return 0 and do not emit any code. */
2819 tail_recursion_args (actuals, formals)
2820 tree actuals, formals;
2822 register tree a = actuals, f = formals;
2824 register rtx *argvec;
2826 /* Check that number and types of actuals are compatible
2827 with the formals. This is not always true in valid C code.
2828 Also check that no formal needs to be addressable
2829 and that all formals are scalars. */
2831 /* Also count the args. */
2833 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2835 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2837 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2840 if (a != 0 || f != 0)
2843 /* Compute all the actuals. */
2845 argvec = (rtx *) alloca (i * sizeof (rtx));
2847 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2848 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2850 /* Find which actual values refer to current values of previous formals.
2851 Copy each of them now, before any formal is changed. */
2853 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2857 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2858 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2859 { copy = 1; break; }
2861 argvec[i] = copy_to_reg (argvec[i]);
2864 /* Store the values of the actuals into the formals. */
2866 for (f = formals, a = actuals, i = 0; f;
2867 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2869 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2870 emit_move_insn (DECL_RTL (f), argvec[i]);
2872 convert_move (DECL_RTL (f), argvec[i],
2873 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2880 /* Generate the RTL code for entering a binding contour.
2881 The variables are declared one by one, by calls to `expand_decl'.
2883 EXIT_FLAG is nonzero if this construct should be visible to
2884 `exit_something'. */
2887 expand_start_bindings (exit_flag)
2890 struct nesting *thisblock = ALLOC_NESTING ();
2891 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2893 /* Make an entry on block_stack for the block we are entering. */
2895 thisblock->next = block_stack;
2896 thisblock->all = nesting_stack;
2897 thisblock->depth = ++nesting_depth;
2898 thisblock->data.block.stack_level = 0;
2899 thisblock->data.block.cleanups = 0;
2900 thisblock->data.block.function_call_count = 0;
2904 if (block_stack->data.block.cleanups == NULL_TREE
2905 && (block_stack->data.block.outer_cleanups == NULL_TREE
2906 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2907 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2909 thisblock->data.block.outer_cleanups
2910 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2911 block_stack->data.block.outer_cleanups);
2914 thisblock->data.block.outer_cleanups = 0;
2918 && !(block_stack->data.block.cleanups == NULL_TREE
2919 && block_stack->data.block.outer_cleanups == NULL_TREE))
2920 thisblock->data.block.outer_cleanups
2921 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2922 block_stack->data.block.outer_cleanups);
2924 thisblock->data.block.outer_cleanups = 0;
2926 thisblock->data.block.label_chain = 0;
2927 thisblock->data.block.innermost_stack_block = stack_block_stack;
2928 thisblock->data.block.first_insn = note;
2929 thisblock->data.block.block_start_count = ++block_start_count;
2930 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2931 block_stack = thisblock;
2932 nesting_stack = thisblock;
2934 if (!output_bytecode)
2936 /* Make a new level for allocating stack slots. */
2941 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2942 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2946 remember_end_note (block)
2947 register tree block;
2949 BLOCK_END_NOTE (block) = last_block_end_note;
2950 last_block_end_note = NULL_RTX;
2953 /* Generate RTL code to terminate a binding contour.
2954 VARS is the chain of VAR_DECL nodes
2955 for the variables bound in this contour.
2956 MARK_ENDS is nonzero if we should put a note at the beginning
2957 and end of this binding contour.
2959 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2960 (That is true automatically if the contour has a saved stack level.) */
2963 expand_end_bindings (vars, mark_ends, dont_jump_in)
2968 register struct nesting *thisblock = block_stack;
2971 if (output_bytecode)
2973 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
2978 for (decl = vars; decl; decl = TREE_CHAIN (decl))
2979 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
2980 && ! DECL_IN_SYSTEM_HEADER (decl))
2981 warning_with_decl (decl, "unused variable `%s'");
2983 if (thisblock->exit_label)
2985 do_pending_stack_adjust ();
2986 emit_label (thisblock->exit_label);
2989 /* If necessary, make a handler for nonlocal gotos taking
2990 place in the function calls in this block. */
2991 if (function_call_count != thisblock->data.block.function_call_count
2993 /* Make handler for outermost block
2994 if there were any nonlocal gotos to this function. */
2995 && (thisblock->next == 0 ? current_function_has_nonlocal_label
2996 /* Make handler for inner block if it has something
2997 special to do when you jump out of it. */
2998 : (thisblock->data.block.cleanups != 0
2999 || thisblock->data.block.stack_level != 0)))
3002 rtx afterward = gen_label_rtx ();
3003 rtx handler_label = gen_label_rtx ();
3004 rtx save_receiver = gen_reg_rtx (Pmode);
3007 /* Don't let jump_optimize delete the handler. */
3008 LABEL_PRESERVE_P (handler_label) = 1;
3010 /* Record the handler address in the stack slot for that purpose,
3011 during this block, saving and restoring the outer value. */
3012 if (thisblock->next != 0)
3014 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3017 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3018 insns = get_insns ();
3020 emit_insns_before (insns, thisblock->data.block.first_insn);
3024 emit_move_insn (nonlocal_goto_handler_slot,
3025 gen_rtx (LABEL_REF, Pmode, handler_label));
3026 insns = get_insns ();
3028 emit_insns_before (insns, thisblock->data.block.first_insn);
3030 /* Jump around the handler; it runs only when specially invoked. */
3031 emit_jump (afterward);
3032 emit_label (handler_label);
3034 #ifdef HAVE_nonlocal_goto
3035 if (! HAVE_nonlocal_goto)
3037 /* First adjust our frame pointer to its actual value. It was
3038 previously set to the start of the virtual area corresponding to
3039 the stacked variables when we branched here and now needs to be
3040 adjusted to the actual hardware fp value.
3042 Assignments are to virtual registers are converted by
3043 instantiate_virtual_regs into the corresponding assignment
3044 to the underlying register (fp in this case) that makes
3045 the original assignment true.
3046 So the following insn will actually be
3047 decrementing fp by STARTING_FRAME_OFFSET. */
3048 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3050 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3051 if (fixed_regs[ARG_POINTER_REGNUM])
3053 #ifdef ELIMINABLE_REGS
3054 /* If the argument pointer can be eliminated in favor of the
3055 frame pointer, we don't need to restore it. We assume here
3056 that if such an elimination is present, it can always be used.
3057 This is the case on all known machines; if we don't make this
3058 assumption, we do unnecessary saving on many machines. */
3059 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3062 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3063 if (elim_regs[i].from == ARG_POINTER_REGNUM
3064 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3067 if (i == sizeof elim_regs / sizeof elim_regs [0])
3070 /* Now restore our arg pointer from the address at which it
3071 was saved in our stack frame.
3072 If there hasn't be space allocated for it yet, make
3074 if (arg_pointer_save_area == 0)
3075 arg_pointer_save_area
3076 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3077 emit_move_insn (virtual_incoming_args_rtx,
3078 /* We need a pseudo here, or else
3079 instantiate_virtual_regs_1 complains. */
3080 copy_to_reg (arg_pointer_save_area));
3085 /* The handler expects the desired label address in the static chain
3086 register. It tests the address and does an appropriate jump
3087 to whatever label is desired. */
3088 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3089 /* Skip any labels we shouldn't be able to jump to from here. */
3090 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3092 rtx not_this = gen_label_rtx ();
3093 rtx this = gen_label_rtx ();
3094 do_jump_if_equal (static_chain_rtx,
3095 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3097 emit_jump (not_this);
3099 expand_goto (TREE_VALUE (link));
3100 emit_label (not_this);
3102 /* If label is not recognized, abort. */
3103 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3106 emit_label (afterward);
3109 /* Don't allow jumping into a block that has cleanups or a stack level. */
3111 || thisblock->data.block.stack_level != 0
3112 || thisblock->data.block.cleanups != 0)
3114 struct label_chain *chain;
3116 /* Any labels in this block are no longer valid to go to.
3117 Mark them to cause an error message. */
3118 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3120 DECL_TOO_LATE (chain->label) = 1;
3121 /* If any goto without a fixup came to this label,
3122 that must be an error, because gotos without fixups
3123 come from outside all saved stack-levels and all cleanups. */
3124 if (TREE_ADDRESSABLE (chain->label))
3125 error_with_decl (chain->label,
3126 "label `%s' used before containing binding contour");
3130 /* Restore stack level in effect before the block
3131 (only if variable-size objects allocated). */
3132 /* Perform any cleanups associated with the block. */
3134 if (thisblock->data.block.stack_level != 0
3135 || thisblock->data.block.cleanups != 0)
3137 /* Only clean up here if this point can actually be reached. */
3138 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3140 /* Don't let cleanups affect ({...}) constructs. */
3141 int old_expr_stmts_for_value = expr_stmts_for_value;
3142 rtx old_last_expr_value = last_expr_value;
3143 tree old_last_expr_type = last_expr_type;
3144 expr_stmts_for_value = 0;
3146 /* Do the cleanups. */
3147 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3149 do_pending_stack_adjust ();
3151 expr_stmts_for_value = old_expr_stmts_for_value;
3152 last_expr_value = old_last_expr_value;
3153 last_expr_type = old_last_expr_type;
3155 /* Restore the stack level. */
3157 if (reachable && thisblock->data.block.stack_level != 0)
3159 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3160 thisblock->data.block.stack_level, NULL_RTX);
3161 if (nonlocal_goto_handler_slot != 0)
3162 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3166 /* Any gotos out of this block must also do these things.
3167 Also report any gotos with fixups that came to labels in this
3169 fixup_gotos (thisblock,
3170 thisblock->data.block.stack_level,
3171 thisblock->data.block.cleanups,
3172 thisblock->data.block.first_insn,
3176 /* Mark the beginning and end of the scope if requested.
3177 We do this now, after running cleanups on the variables
3178 just going out of scope, so they are in scope for their cleanups. */
3181 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3183 /* Get rid of the beginning-mark if we don't make an end-mark. */
3184 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3186 /* If doing stupid register allocation, make sure lives of all
3187 register variables declared here extend thru end of scope. */
3190 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3192 rtx rtl = DECL_RTL (decl);
3193 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3197 /* Restore block_stack level for containing block. */
3199 stack_block_stack = thisblock->data.block.innermost_stack_block;
3200 POPSTACK (block_stack);
3202 /* Pop the stack slot nesting and free any slots at this level. */
3207 /* End a binding contour.
3208 VARS is the chain of VAR_DECL nodes for the variables bound
3209 in this contour. MARK_ENDS is nonzer if we should put a note
3210 at the beginning and end of this binding contour.
3211 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3215 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3220 struct nesting *thisbind = nesting_stack;
3224 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3225 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3226 warning_with_decl (decl, "unused variable `%s'");
3228 if (thisbind->exit_label)
3229 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3231 /* Pop block/bindings off stack */
3232 POPSTACK (block_stack);
3235 /* Generate RTL for the automatic variable declaration DECL.
3236 (Other kinds of declarations are simply ignored if seen here.)
3237 CLEANUP is an expression to be executed at exit from this binding contour;
3238 for example, in C++, it might call the destructor for this variable.
3240 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3241 either before or after calling `expand_decl' but before compiling
3242 any subsequent expressions. This is because CLEANUP may be expanded
3243 more than once, on different branches of execution.
3244 For the same reason, CLEANUP may not contain a CALL_EXPR
3245 except as its topmost node--else `preexpand_calls' would get confused.
3247 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3248 that is not associated with any particular variable.
3250 There is no special support here for C++ constructors.
3251 They should be handled by the proper code in DECL_INITIAL. */
3257 struct nesting *thisblock = block_stack;
3260 if (output_bytecode)
3262 bc_expand_decl (decl, 0);
3266 type = TREE_TYPE (decl);
3268 /* Only automatic variables need any expansion done.
3269 Static and external variables, and external functions,
3270 will be handled by `assemble_variable' (called from finish_decl).
3271 TYPE_DECL and CONST_DECL require nothing.
3272 PARM_DECLs are handled in `assign_parms'. */
3274 if (TREE_CODE (decl) != VAR_DECL)
3276 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3279 /* Create the RTL representation for the variable. */
3281 if (type == error_mark_node)
3282 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3283 else if (DECL_SIZE (decl) == 0)
3284 /* Variable with incomplete type. */
3286 if (DECL_INITIAL (decl) == 0)
3287 /* Error message was already done; now avoid a crash. */
3288 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3290 /* An initializer is going to decide the size of this array.
3291 Until we know the size, represent its address with a reg. */
3292 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3293 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3295 else if (DECL_MODE (decl) != BLKmode
3296 /* If -ffloat-store, don't put explicit float vars
3298 && !(flag_float_store
3299 && TREE_CODE (type) == REAL_TYPE)
3300 && ! TREE_THIS_VOLATILE (decl)
3301 && ! TREE_ADDRESSABLE (decl)
3302 && (DECL_REGISTER (decl) || ! obey_regdecls))
3304 /* Automatic variable that can go in a register. */
3305 int unsignedp = TREE_UNSIGNED (type);
3306 enum machine_mode reg_mode
3307 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3309 if (TREE_CODE (type) == COMPLEX_TYPE)
3311 rtx realpart, imagpart;
3312 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3314 /* For a complex type variable, make a CONCAT of two pseudos
3315 so that the real and imaginary parts
3316 can be allocated separately. */
3317 realpart = gen_reg_rtx (partmode);
3318 REG_USERVAR_P (realpart) = 1;
3319 imagpart = gen_reg_rtx (partmode);
3320 REG_USERVAR_P (imagpart) = 1;
3321 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3325 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3326 if (TREE_CODE (type) == POINTER_TYPE)
3327 mark_reg_pointer (DECL_RTL (decl));
3328 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3331 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3333 /* Variable of fixed size that goes on the stack. */
3337 /* If we previously made RTL for this decl, it must be an array
3338 whose size was determined by the initializer.
3339 The old address was a register; set that register now
3340 to the proper address. */
3341 if (DECL_RTL (decl) != 0)
3343 if (GET_CODE (DECL_RTL (decl)) != MEM
3344 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3346 oldaddr = XEXP (DECL_RTL (decl), 0);
3350 = assign_stack_temp (DECL_MODE (decl),
3351 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3352 + BITS_PER_UNIT - 1)
3355 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3357 /* Set alignment we actually gave this decl. */
3358 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3359 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3363 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3364 if (addr != oldaddr)
3365 emit_move_insn (oldaddr, addr);
3368 /* If this is a memory ref that contains aggregate components,
3369 mark it as such for cse and loop optimize. */
3370 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3372 /* If this is in memory because of -ffloat-store,
3373 set the volatile bit, to prevent optimizations from
3374 undoing the effects. */
3375 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3376 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3380 /* Dynamic-size object: must push space on the stack. */
3384 /* Record the stack pointer on entry to block, if have
3385 not already done so. */
3386 if (thisblock->data.block.stack_level == 0)
3388 do_pending_stack_adjust ();
3389 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3390 &thisblock->data.block.stack_level,
3391 thisblock->data.block.first_insn);
3392 stack_block_stack = thisblock;
3395 /* Compute the variable's size, in bytes. */
3396 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3398 size_int (BITS_PER_UNIT)),
3399 NULL_RTX, VOIDmode, 0);
3402 /* Allocate space on the stack for the variable. */
3403 address = allocate_dynamic_stack_space (size, NULL_RTX,
3406 /* Reference the variable indirect through that rtx. */
3407 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3409 /* If this is a memory ref that contains aggregate components,
3410 mark it as such for cse and loop optimize. */
3411 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3413 /* Indicate the alignment we actually gave this variable. */
3414 #ifdef STACK_BOUNDARY
3415 DECL_ALIGN (decl) = STACK_BOUNDARY;
3417 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3421 if (TREE_THIS_VOLATILE (decl))
3422 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3423 #if 0 /* A variable is not necessarily unchanging
3424 just because it is const. RTX_UNCHANGING_P
3425 means no change in the function,
3426 not merely no change in the variable's scope.
3427 It is correct to set RTX_UNCHANGING_P if the variable's scope
3428 is the whole function. There's no convenient way to test that. */
3429 if (TREE_READONLY (decl))
3430 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3433 /* If doing stupid register allocation, make sure life of any
3434 register variable starts here, at the start of its scope. */
3437 use_variable (DECL_RTL (decl));
3441 /* Generate code for the automatic variable declaration DECL. For
3442 most variables this just means we give it a stack offset. The
3443 compiler sometimes emits cleanups without variables and we will
3444 have to deal with those too. */
3447 bc_expand_decl (decl, cleanup)
3455 /* A cleanup with no variable. */
3462 /* Only auto variables need any work. */
3463 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3466 type = TREE_TYPE (decl);
3468 if (type == error_mark_node)
3469 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3471 else if (DECL_SIZE (decl) == 0)
3473 /* Variable with incomplete type. The stack offset herein will be
3474 fixed later in expand_decl_init (). */
3475 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3477 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3479 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3483 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3486 /* Emit code to perform the initialization of a declaration DECL. */
3489 expand_decl_init (decl)
3492 int was_used = TREE_USED (decl);
3494 if (output_bytecode)
3496 bc_expand_decl_init (decl);
3500 /* If this is a CONST_DECL, we don't have to generate any code, but
3501 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3502 to be set while in the obstack containing the constant. If we don't
3503 do this, we can lose if we have functions nested three deep and the middle
3504 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3505 the innermost function is the first to expand that STRING_CST. */
3506 if (TREE_CODE (decl) == CONST_DECL)
3508 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3509 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3510 EXPAND_INITIALIZER);
3514 if (TREE_STATIC (decl))
3517 /* Compute and store the initial value now. */
3519 if (DECL_INITIAL (decl) == error_mark_node)
3521 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3522 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3523 || code == POINTER_TYPE)
3524 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3528 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3530 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3531 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3535 /* Don't let the initialization count as "using" the variable. */
3536 TREE_USED (decl) = was_used;
3538 /* Free any temporaries we made while initializing the decl. */
3539 preserve_temp_slots (NULL_RTX);
3543 /* Expand initialization for variable-sized types. Allocate array
3544 using newlocalSI and set local variable, which is a pointer to the
3548 bc_expand_variable_local_init (decl)
3551 /* Evaluate size expression and coerce to SI */
3552 bc_expand_expr (DECL_SIZE (decl));
3554 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3555 no coercion is necessary (?) */
3557 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3558 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3560 /* Emit code to allocate array */
3561 bc_emit_instruction (newlocalSI);
3563 /* Store array pointer in local variable. This is the only instance
3564 where we actually want the address of the pointer to the
3565 variable-size block, rather than the pointer itself. We avoid
3566 using expand_address() since that would cause the pointer to be
3567 pushed rather than its address. Hence the hard-coded reference;
3568 notice also that the variable is always local (no global
3569 variable-size type variables). */
3571 bc_load_localaddr (DECL_RTL (decl));
3572 bc_emit_instruction (storeP);
3576 /* Emit code to initialize a declaration. */
3579 bc_expand_decl_init (decl)
3582 int org_stack_depth;
3584 /* Statical initializers are handled elsewhere */
3586 if (TREE_STATIC (decl))
3589 /* Memory original stack depth */
3590 org_stack_depth = stack_depth;
3592 /* If the type is variable-size, we first create its space (we ASSUME
3593 it CAN'T be static). We do this regardless of whether there's an
3594 initializer assignment or not. */
3596 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3597 bc_expand_variable_local_init (decl);
3599 /* Expand initializer assignment */
3600 if (DECL_INITIAL (decl) == error_mark_node)
3602 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3604 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3605 || code == POINTER_TYPE)
3607 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3609 else if (DECL_INITIAL (decl))
3610 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3612 /* Restore stack depth */
3613 if (org_stack_depth > stack_depth)
3616 bc_adjust_stack (stack_depth - org_stack_depth);
3620 /* CLEANUP is an expression to be executed at exit from this binding contour;
3621 for example, in C++, it might call the destructor for this variable.
3623 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3624 either before or after calling `expand_decl' but before compiling
3625 any subsequent expressions. This is because CLEANUP may be expanded
3626 more than once, on different branches of execution.
3627 For the same reason, CLEANUP may not contain a CALL_EXPR
3628 except as its topmost node--else `preexpand_calls' would get confused.
3630 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3631 that is not associated with any particular variable. */
3634 expand_decl_cleanup (decl, cleanup)
3637 struct nesting *thisblock = block_stack;
3639 /* Error if we are not in any block. */
3643 /* Record the cleanup if there is one. */
3647 thisblock->data.block.cleanups
3648 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3649 /* If this block has a cleanup, it belongs in stack_block_stack. */
3650 stack_block_stack = thisblock;
3651 (*interim_eh_hook) (NULL_TREE);
3656 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3657 DECL_ELTS is the list of elements that belong to DECL's type.
3658 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3661 expand_anon_union_decl (decl, cleanup, decl_elts)
3662 tree decl, cleanup, decl_elts;
3664 struct nesting *thisblock = block_stack;
3667 expand_decl (decl, cleanup);
3668 x = DECL_RTL (decl);
3672 tree decl_elt = TREE_VALUE (decl_elts);
3673 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3674 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3676 /* Propagate the union's alignment to the elements. */
3677 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3679 /* If the element has BLKmode and the union doesn't, the union is
3680 aligned such that the element doesn't need to have BLKmode, so
3681 change the element's mode to the appropriate one for its size. */
3682 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3683 DECL_MODE (decl_elt) = mode
3684 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3687 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3688 instead create a new MEM rtx with the proper mode. */
3689 if (GET_CODE (x) == MEM)
3691 if (mode == GET_MODE (x))
3692 DECL_RTL (decl_elt) = x;
3695 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3696 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3697 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3700 else if (GET_CODE (x) == REG)
3702 if (mode == GET_MODE (x))
3703 DECL_RTL (decl_elt) = x;
3705 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3710 /* Record the cleanup if there is one. */
3713 thisblock->data.block.cleanups
3714 = temp_tree_cons (decl_elt, cleanup_elt,
3715 thisblock->data.block.cleanups);
3717 decl_elts = TREE_CHAIN (decl_elts);
3721 /* Expand a list of cleanups LIST.
3722 Elements may be expressions or may be nested lists.
3724 If DONT_DO is nonnull, then any list-element
3725 whose TREE_PURPOSE matches DONT_DO is omitted.
3726 This is sometimes used to avoid a cleanup associated with
3727 a value that is being returned out of the scope.
3729 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3730 goto and handle protection regions specially in that case.
3732 If REACHABLE, we emit code, otherwise just inform the exception handling
3733 code about this finalization. */
3736 expand_cleanups (list, dont_do, in_fixup, reachable)
3743 for (tail = list; tail; tail = TREE_CHAIN (tail))
3744 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3746 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3747 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3751 (*interim_eh_hook) (TREE_VALUE (tail));
3755 /* Cleanups may be run multiple times. For example,
3756 when exiting a binding contour, we expand the
3757 cleanups associated with that contour. When a goto
3758 within that binding contour has a target outside that
3759 contour, it will expand all cleanups from its scope to
3760 the target. Though the cleanups are expanded multiple
3761 times, the control paths are non-overlapping so the
3762 cleanups will not be executed twice. */
3763 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3770 /* Move all cleanups from the current block_stack
3771 to the containing block_stack, where they are assumed to
3772 have been created. If anything can cause a temporary to
3773 be created, but not expanded for more than one level of
3774 block_stacks, then this code will have to change. */
3779 struct nesting *block = block_stack;
3780 struct nesting *outer = block->next;
3782 outer->data.block.cleanups
3783 = chainon (block->data.block.cleanups,
3784 outer->data.block.cleanups);
3785 block->data.block.cleanups = 0;
3789 last_cleanup_this_contour ()
3791 if (block_stack == 0)
3794 return block_stack->data.block.cleanups;
3797 /* Return 1 if there are any pending cleanups at this point.
3798 If THIS_CONTOUR is nonzero, check the current contour as well.
3799 Otherwise, look only at the contours that enclose this one. */
3802 any_pending_cleanups (this_contour)
3805 struct nesting *block;
3807 if (block_stack == 0)
3810 if (this_contour && block_stack->data.block.cleanups != NULL)
3812 if (block_stack->data.block.cleanups == 0
3813 && (block_stack->data.block.outer_cleanups == 0
3815 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3820 for (block = block_stack->next; block; block = block->next)
3821 if (block->data.block.cleanups != 0)
3827 /* Enter a case (Pascal) or switch (C) statement.
3828 Push a block onto case_stack and nesting_stack
3829 to accumulate the case-labels that are seen
3830 and to record the labels generated for the statement.
3832 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3833 Otherwise, this construct is transparent for `exit_something'.
3835 EXPR is the index-expression to be dispatched on.
3836 TYPE is its nominal type. We could simply convert EXPR to this type,
3837 but instead we take short cuts. */
3840 expand_start_case (exit_flag, expr, type, printname)
3846 register struct nesting *thiscase = ALLOC_NESTING ();
3848 /* Make an entry on case_stack for the case we are entering. */
3850 thiscase->next = case_stack;
3851 thiscase->all = nesting_stack;
3852 thiscase->depth = ++nesting_depth;
3853 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3854 thiscase->data.case_stmt.case_list = 0;
3855 thiscase->data.case_stmt.index_expr = expr;
3856 thiscase->data.case_stmt.nominal_type = type;
3857 thiscase->data.case_stmt.default_label = 0;
3858 thiscase->data.case_stmt.num_ranges = 0;
3859 thiscase->data.case_stmt.printname = printname;
3860 thiscase->data.case_stmt.seenlabel = 0;
3861 case_stack = thiscase;
3862 nesting_stack = thiscase;
3864 if (output_bytecode)
3866 bc_expand_start_case (thiscase, expr, type, printname);
3870 do_pending_stack_adjust ();
3872 /* Make sure case_stmt.start points to something that won't
3873 need any transformation before expand_end_case. */
3874 if (GET_CODE (get_last_insn ()) != NOTE)
3875 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3877 thiscase->data.case_stmt.start = get_last_insn ();
3881 /* Enter a case statement. It is assumed that the caller has pushed
3882 the current context onto the case stack. */
3885 bc_expand_start_case (thiscase, expr, type, printname)
3886 struct nesting *thiscase;
3891 bc_expand_expr (expr);
3892 bc_expand_conversion (TREE_TYPE (expr), type);
3894 /* For cases, the skip is a place we jump to that's emitted after
3895 the size of the jump table is known. */
3897 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3898 bc_emit_bytecode (jump);
3899 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3901 #ifdef DEBUG_PRINT_CODE
3902 fputc ('\n', stderr);
3907 /* Start a "dummy case statement" within which case labels are invalid
3908 and are not connected to any larger real case statement.
3909 This can be used if you don't want to let a case statement jump
3910 into the middle of certain kinds of constructs. */
3913 expand_start_case_dummy ()
3915 register struct nesting *thiscase = ALLOC_NESTING ();
3917 /* Make an entry on case_stack for the dummy. */
3919 thiscase->next = case_stack;
3920 thiscase->all = nesting_stack;
3921 thiscase->depth = ++nesting_depth;
3922 thiscase->exit_label = 0;
3923 thiscase->data.case_stmt.case_list = 0;
3924 thiscase->data.case_stmt.start = 0;
3925 thiscase->data.case_stmt.nominal_type = 0;
3926 thiscase->data.case_stmt.default_label = 0;
3927 thiscase->data.case_stmt.num_ranges = 0;
3928 case_stack = thiscase;
3929 nesting_stack = thiscase;
3932 /* End a dummy case statement. */
3935 expand_end_case_dummy ()
3937 POPSTACK (case_stack);
3940 /* Return the data type of the index-expression
3941 of the innermost case statement, or null if none. */
3944 case_index_expr_type ()
3947 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3951 /* Accumulate one case or default label inside a case or switch statement.
3952 VALUE is the value of the case (a null pointer, for a default label).
3953 The function CONVERTER, when applied to arguments T and V,
3954 converts the value V to the type T.
3956 If not currently inside a case or switch statement, return 1 and do
3957 nothing. The caller will print a language-specific error message.
3958 If VALUE is a duplicate or overlaps, return 2 and do nothing
3959 except store the (first) duplicate node in *DUPLICATE.
3960 If VALUE is out of range, return 3 and do nothing.
3961 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3962 Return 0 on success.
3964 Extended to handle range statements. */
3967 pushcase (value, converter, label, duplicate)
3968 register tree value;
3969 tree (*converter) PROTO((tree, tree));
3970 register tree label;
3973 register struct case_node **l;
3974 register struct case_node *n;
3978 if (output_bytecode)
3979 return bc_pushcase (value, label);
3981 /* Fail if not inside a real case statement. */
3982 if (! (case_stack && case_stack->data.case_stmt.start))
3985 if (stack_block_stack
3986 && stack_block_stack->depth > case_stack->depth)
3989 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
3990 nominal_type = case_stack->data.case_stmt.nominal_type;
3992 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3993 if (index_type == error_mark_node)
3996 /* Convert VALUE to the type in which the comparisons are nominally done. */
3998 value = (*converter) (nominal_type, value);
4000 /* If this is the first label, warn if any insns have been emitted. */
4001 if (case_stack->data.case_stmt.seenlabel == 0)
4004 for (insn = case_stack->data.case_stmt.start;
4006 insn = NEXT_INSN (insn))
4008 if (GET_CODE (insn) == CODE_LABEL)
4010 if (GET_CODE (insn) != NOTE
4011 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4013 warning ("unreachable code at beginning of %s",
4014 case_stack->data.case_stmt.printname);
4019 case_stack->data.case_stmt.seenlabel = 1;
4021 /* Fail if this value is out of range for the actual type of the index
4022 (which may be narrower than NOMINAL_TYPE). */
4023 if (value != 0 && ! int_fits_type_p (value, index_type))
4026 /* Fail if this is a duplicate or overlaps another entry. */
4029 if (case_stack->data.case_stmt.default_label != 0)
4031 *duplicate = case_stack->data.case_stmt.default_label;
4034 case_stack->data.case_stmt.default_label = label;
4038 /* Find the elt in the chain before which to insert the new value,
4039 to keep the chain sorted in increasing order.
4040 But report an error if this element is a duplicate. */
4041 for (l = &case_stack->data.case_stmt.case_list;
4042 /* Keep going past elements distinctly less than VALUE. */
4043 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4048 /* Element we will insert before must be distinctly greater;
4049 overlap means error. */
4050 if (! tree_int_cst_lt (value, (*l)->low))
4052 *duplicate = (*l)->code_label;
4057 /* Add this label to the chain, and succeed.
4058 Copy VALUE so it is on temporary rather than momentary
4059 obstack and will thus survive till the end of the case statement. */
4060 n = (struct case_node *) oballoc (sizeof (struct case_node));
4063 n->high = n->low = copy_node (value);
4064 n->code_label = label;
4068 expand_label (label);
4072 /* Like pushcase but this case applies to all values
4073 between VALUE1 and VALUE2 (inclusive).
4074 The return value is the same as that of pushcase
4075 but there is one additional error code:
4076 4 means the specified range was empty. */
4079 pushcase_range (value1, value2, converter, label, duplicate)
4080 register tree value1, value2;
4081 tree (*converter) PROTO((tree, tree));
4082 register tree label;
4085 register struct case_node **l;
4086 register struct case_node *n;
4090 /* Fail if not inside a real case statement. */
4091 if (! (case_stack && case_stack->data.case_stmt.start))
4094 if (stack_block_stack
4095 && stack_block_stack->depth > case_stack->depth)
4098 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4099 nominal_type = case_stack->data.case_stmt.nominal_type;
4101 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4102 if (index_type == error_mark_node)
4105 /* If this is the first label, warn if any insns have been emitted. */
4106 if (case_stack->data.case_stmt.seenlabel == 0)
4109 for (insn = case_stack->data.case_stmt.start;
4111 insn = NEXT_INSN (insn))
4113 if (GET_CODE (insn) == CODE_LABEL)
4115 if (GET_CODE (insn) != NOTE
4116 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4118 warning ("unreachable code at beginning of %s",
4119 case_stack->data.case_stmt.printname);
4124 case_stack->data.case_stmt.seenlabel = 1;
4126 /* Convert VALUEs to type in which the comparisons are nominally done. */
4127 if (value1 == 0) /* Negative infinity. */
4128 value1 = TYPE_MIN_VALUE(index_type);
4129 value1 = (*converter) (nominal_type, value1);
4131 if (value2 == 0) /* Positive infinity. */
4132 value2 = TYPE_MAX_VALUE(index_type);
4133 value2 = (*converter) (nominal_type, value2);
4135 /* Fail if these values are out of range. */
4136 if (! int_fits_type_p (value1, index_type))
4139 if (! int_fits_type_p (value2, index_type))
4142 /* Fail if the range is empty. */
4143 if (tree_int_cst_lt (value2, value1))
4146 /* If the bounds are equal, turn this into the one-value case. */
4147 if (tree_int_cst_equal (value1, value2))
4148 return pushcase (value1, converter, label, duplicate);
4150 /* Find the elt in the chain before which to insert the new value,
4151 to keep the chain sorted in increasing order.
4152 But report an error if this element is a duplicate. */
4153 for (l = &case_stack->data.case_stmt.case_list;
4154 /* Keep going past elements distinctly less than this range. */
4155 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4160 /* Element we will insert before must be distinctly greater;
4161 overlap means error. */
4162 if (! tree_int_cst_lt (value2, (*l)->low))
4164 *duplicate = (*l)->code_label;
4169 /* Add this label to the chain, and succeed.
4170 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4171 obstack and will thus survive till the end of the case statement. */
4173 n = (struct case_node *) oballoc (sizeof (struct case_node));
4176 n->low = copy_node (value1);
4177 n->high = copy_node (value2);
4178 n->code_label = label;
4181 expand_label (label);
4183 case_stack->data.case_stmt.num_ranges++;
4189 /* Accumulate one case or default label; VALUE is the value of the
4190 case, or nil for a default label. If not currently inside a case,
4191 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4192 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4193 Return 0 on success. This function is a leftover from the earlier
4194 bytecode compiler, which was based on gcc 1.37. It should be
4195 merged into pushcase. */
4198 bc_pushcase (value, label)
4202 struct nesting *thiscase = case_stack;
4203 struct case_node *case_label, *new_label;
4208 /* Fail if duplicate, overlap, or out of type range. */
4211 value = convert (thiscase->data.case_stmt.nominal_type, value);
4212 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4215 for (case_label = thiscase->data.case_stmt.case_list;
4216 case_label->left; case_label = case_label->left)
4217 if (! tree_int_cst_lt (case_label->left->high, value))
4220 if (case_label != thiscase->data.case_stmt.case_list
4221 && ! tree_int_cst_lt (case_label->high, value)
4222 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4225 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4226 new_label->low = new_label->high = copy_node (value);
4227 new_label->code_label = label;
4228 new_label->left = case_label->left;
4230 case_label->left = new_label;
4231 thiscase->data.case_stmt.num_ranges++;
4235 if (thiscase->data.case_stmt.default_label)
4237 thiscase->data.case_stmt.default_label = label;
4240 expand_label (label);
4244 /* Returns the number of possible values of TYPE.
4245 Returns -1 if the number is unknown or variable.
4246 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4247 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4248 do not increase monotonically (there may be duplicates);
4249 to 1 if the values increase monotonically, but not always by 1;
4250 otherwise sets it to 0. */
4253 all_cases_count (type, spareness)
4257 HOST_WIDE_INT count, count_high = 0;
4260 switch (TREE_CODE (type))
4267 count = 1 << BITS_PER_UNIT;
4271 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4272 || TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST)
4277 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4278 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4279 but with overflow checking. */
4280 tree mint = TYPE_MIN_VALUE (type);
4281 tree maxt = TYPE_MAX_VALUE (type);
4282 HOST_WIDE_INT lo, hi;
4283 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4285 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4287 add_double (lo, hi, 1, 0, &lo, &hi);
4288 if (hi != 0 || lo < 0)
4295 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4297 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4298 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4299 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4300 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4304 if (*spareness == 1)
4306 tree prev = TREE_VALUE (TYPE_VALUES (type));
4307 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4309 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4314 prev = TREE_VALUE (t);
4323 #define BITARRAY_TEST(ARRAY, INDEX) \
4324 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4325 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4326 #define BITARRAY_SET(ARRAY, INDEX) \
4327 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4328 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4330 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4331 with the case values we have seen, assuming the case expression
4333 SPARSENESS is as determined by all_cases_count.
4335 The time needed is proportional to COUNT, unless
4336 SPARSENESS is 2, in which case quadratic time is needed. */
4339 mark_seen_cases (type, cases_seen, count, sparseness)
4341 unsigned char *cases_seen;
4347 tree next_node_to_try = NULL_TREE;
4348 long next_node_offset = 0;
4350 register struct case_node *n;
4351 tree val = make_node (INTEGER_CST);
4352 TREE_TYPE (val) = type;
4353 for (n = case_stack->data.case_stmt.case_list; n;
4356 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4357 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4358 while ( ! tree_int_cst_lt (n->high, val))
4360 /* Calculate (into xlo) the "offset" of the integer (val).
4361 The element with lowest value has offset 0, the next smallest
4362 element has offset 1, etc. */
4364 HOST_WIDE_INT xlo, xhi;
4366 if (sparseness == 2)
4368 /* This less efficient loop is only needed to handle
4369 duplicate case values (multiple enum constants
4370 with the same value). */
4371 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4372 t = TREE_CHAIN (t), xlo++)
4374 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4375 BITARRAY_SET (cases_seen, xlo);
4380 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4382 /* The TYPE_VALUES will be in increasing order, so
4383 starting searching where we last ended. */
4384 t = next_node_to_try;
4385 xlo = next_node_offset;
4391 t = TYPE_VALUES (type);
4394 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4396 next_node_to_try = TREE_CHAIN (t);
4397 next_node_offset = xlo + 1;
4402 if (t == next_node_to_try)
4408 t = TYPE_MIN_VALUE (type);
4410 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4414 add_double (xlo, xhi,
4415 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4419 if (xhi == 0 && xlo >= 0 && xlo < count)
4420 BITARRAY_SET (cases_seen, xlo);
4422 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4424 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4429 /* Called when the index of a switch statement is an enumerated type
4430 and there is no default label.
4432 Checks that all enumeration literals are covered by the case
4433 expressions of a switch. Also, warn if there are any extra
4434 switch cases that are *not* elements of the enumerated type.
4436 If all enumeration literals were covered by the case expressions,
4437 turn one of the expressions into the default expression since it should
4438 not be possible to fall through such a switch. */
4441 check_for_full_enumeration_handling (type)
4444 register struct case_node *n;
4445 register struct case_node **l;
4446 register tree chain;
4449 /* True iff the selector type is a numbered set mode. */
4452 /* The number of possible selector values. */
4455 /* For each possible selector value. a one iff it has been matched
4456 by a case value alternative. */
4457 unsigned char *cases_seen;
4459 /* The allocated size of cases_seen, in chars. */
4463 if (output_bytecode)
4465 bc_check_for_full_enumeration_handling (type);
4472 size = all_cases_count (type, &sparseness);
4473 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4475 if (size > 0 && size < 600000
4476 /* We deliberately use malloc here - not xmalloc. */
4477 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4480 tree v = TYPE_VALUES (type);
4481 bzero (cases_seen, bytes_needed);
4483 /* The time complexity of this code is normally O(N), where
4484 N being the number of members in the enumerated type.
4485 However, if type is a ENUMERAL_TYPE whose values do not
4486 increase monotonically, quadratic time may be needed. */
4488 mark_seen_cases (type, cases_seen, size, sparseness);
4490 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4492 if (BITARRAY_TEST(cases_seen, i) == 0)
4493 warning ("enumeration value `%s' not handled in switch",
4494 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4500 /* Now we go the other way around; we warn if there are case
4501 expressions that don't correspond to enumerators. This can
4502 occur since C and C++ don't enforce type-checking of
4503 assignments to enumeration variables. */
4506 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4508 for (chain = TYPE_VALUES (type);
4509 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4510 chain = TREE_CHAIN (chain))
4515 if (TYPE_NAME (type) == 0)
4516 warning ("case value `%d' not in enumerated type",
4517 TREE_INT_CST_LOW (n->low));
4519 warning ("case value `%d' not in enumerated type `%s'",
4520 TREE_INT_CST_LOW (n->low),
4521 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4524 : DECL_NAME (TYPE_NAME (type))));
4526 if (!tree_int_cst_equal (n->low, n->high))
4528 for (chain = TYPE_VALUES (type);
4529 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4530 chain = TREE_CHAIN (chain))
4535 if (TYPE_NAME (type) == 0)
4536 warning ("case value `%d' not in enumerated type",
4537 TREE_INT_CST_LOW (n->high));
4539 warning ("case value `%d' not in enumerated type `%s'",
4540 TREE_INT_CST_LOW (n->high),
4541 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4544 : DECL_NAME (TYPE_NAME (type))));
4550 /* ??? This optimization is disabled because it causes valid programs to
4551 fail. ANSI C does not guarantee that an expression with enum type
4552 will have a value that is the same as one of the enumeration literals. */
4554 /* If all values were found as case labels, make one of them the default
4555 label. Thus, this switch will never fall through. We arbitrarily pick
4556 the last one to make the default since this is likely the most
4557 efficient choice. */
4561 for (l = &case_stack->data.case_stmt.case_list;
4566 case_stack->data.case_stmt.default_label = (*l)->code_label;
4573 /* Check that all enumeration literals are covered by the case
4574 expressions of a switch. Also warn if there are any cases
4575 that are not elements of the enumerated type. */
4578 bc_check_for_full_enumeration_handling (type)
4581 struct nesting *thiscase = case_stack;
4582 struct case_node *c;
4585 /* Check for enums not handled. */
4586 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4588 for (c = thiscase->data.case_stmt.case_list->left;
4589 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4592 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4593 warning ("enumerated value `%s' not handled in switch",
4594 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4597 /* Check for cases not in the enumeration. */
4598 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4600 for (e = TYPE_VALUES (type);
4601 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4605 warning ("case value `%d' not in enumerated type `%s'",
4606 TREE_INT_CST_LOW (c->low),
4607 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4609 : DECL_NAME (TYPE_NAME (type))));
4613 /* Terminate a case (Pascal) or switch (C) statement
4614 in which ORIG_INDEX is the expression to be tested.
4615 Generate the code to test it and jump to the right place. */
4618 expand_end_case (orig_index)
4621 tree minval, maxval, range, orig_minval;
4622 rtx default_label = 0;
4623 register struct case_node *n;
4631 register struct nesting *thiscase = case_stack;
4632 tree index_expr, index_type;
4635 if (output_bytecode)
4637 bc_expand_end_case (orig_index);
4641 table_label = gen_label_rtx ();
4642 index_expr = thiscase->data.case_stmt.index_expr;
4643 index_type = TREE_TYPE (index_expr);
4644 unsignedp = TREE_UNSIGNED (index_type);
4646 do_pending_stack_adjust ();
4648 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4649 if (index_type != error_mark_node)
4651 /* If switch expression was an enumerated type, check that all
4652 enumeration literals are covered by the cases.
4653 No sense trying this if there's a default case, however. */
4655 if (!thiscase->data.case_stmt.default_label
4656 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4657 && TREE_CODE (index_expr) != INTEGER_CST)
4658 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4660 /* If this is the first label, warn if any insns have been emitted. */
4661 if (thiscase->data.case_stmt.seenlabel == 0)
4664 for (insn = get_last_insn ();
4665 insn != case_stack->data.case_stmt.start;
4666 insn = PREV_INSN (insn))
4667 if (GET_CODE (insn) != NOTE
4668 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4670 warning ("unreachable code at beginning of %s",
4671 case_stack->data.case_stmt.printname);
4676 /* If we don't have a default-label, create one here,
4677 after the body of the switch. */
4678 if (thiscase->data.case_stmt.default_label == 0)
4680 thiscase->data.case_stmt.default_label
4681 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4682 expand_label (thiscase->data.case_stmt.default_label);
4684 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4686 before_case = get_last_insn ();
4688 /* Simplify the case-list before we count it. */
4689 group_case_nodes (thiscase->data.case_stmt.case_list);
4691 /* Get upper and lower bounds of case values.
4692 Also convert all the case values to the index expr's data type. */
4695 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4697 /* Check low and high label values are integers. */
4698 if (TREE_CODE (n->low) != INTEGER_CST)
4700 if (TREE_CODE (n->high) != INTEGER_CST)
4703 n->low = convert (index_type, n->low);
4704 n->high = convert (index_type, n->high);
4706 /* Count the elements and track the largest and smallest
4707 of them (treating them as signed even if they are not). */
4715 if (INT_CST_LT (n->low, minval))
4717 if (INT_CST_LT (maxval, n->high))
4720 /* A range counts double, since it requires two compares. */
4721 if (! tree_int_cst_equal (n->low, n->high))
4725 orig_minval = minval;
4727 /* Compute span of values. */
4729 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4733 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4735 emit_jump (default_label);
4738 /* If range of values is much bigger than number of values,
4739 make a sequence of conditional branches instead of a dispatch.
4740 If the switch-index is a constant, do it this way
4741 because we can optimize it. */
4743 #ifndef CASE_VALUES_THRESHOLD
4745 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4747 /* If machine does not have a case insn that compares the
4748 bounds, this means extra overhead for dispatch tables
4749 which raises the threshold for using them. */
4750 #define CASE_VALUES_THRESHOLD 5
4751 #endif /* HAVE_casesi */
4752 #endif /* CASE_VALUES_THRESHOLD */
4754 else if (TREE_INT_CST_HIGH (range) != 0
4755 || count < CASE_VALUES_THRESHOLD
4756 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4758 || TREE_CODE (index_expr) == INTEGER_CST
4759 /* These will reduce to a constant. */
4760 || (TREE_CODE (index_expr) == CALL_EXPR
4761 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4762 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4763 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4764 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4765 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4767 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4769 /* If the index is a short or char that we do not have
4770 an insn to handle comparisons directly, convert it to
4771 a full integer now, rather than letting each comparison
4772 generate the conversion. */
4774 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4775 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4776 == CODE_FOR_nothing))
4778 enum machine_mode wider_mode;
4779 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4780 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4781 if (cmp_optab->handlers[(int) wider_mode].insn_code
4782 != CODE_FOR_nothing)
4784 index = convert_to_mode (wider_mode, index, unsignedp);
4790 do_pending_stack_adjust ();
4792 index = protect_from_queue (index, 0);
4793 if (GET_CODE (index) == MEM)
4794 index = copy_to_reg (index);
4795 if (GET_CODE (index) == CONST_INT
4796 || TREE_CODE (index_expr) == INTEGER_CST)
4798 /* Make a tree node with the proper constant value
4799 if we don't already have one. */
4800 if (TREE_CODE (index_expr) != INTEGER_CST)
4803 = build_int_2 (INTVAL (index),
4804 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4805 index_expr = convert (index_type, index_expr);
4808 /* For constant index expressions we need only
4809 issue a unconditional branch to the appropriate
4810 target code. The job of removing any unreachable
4811 code is left to the optimisation phase if the
4812 "-O" option is specified. */
4813 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4814 if (! tree_int_cst_lt (index_expr, n->low)
4815 && ! tree_int_cst_lt (n->high, index_expr))
4819 emit_jump (label_rtx (n->code_label));
4821 emit_jump (default_label);
4825 /* If the index expression is not constant we generate
4826 a binary decision tree to select the appropriate
4827 target code. This is done as follows:
4829 The list of cases is rearranged into a binary tree,
4830 nearly optimal assuming equal probability for each case.
4832 The tree is transformed into RTL, eliminating
4833 redundant test conditions at the same time.
4835 If program flow could reach the end of the
4836 decision tree an unconditional jump to the
4837 default code is emitted. */
4840 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4841 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4842 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4844 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4845 default_label, index_type);
4846 emit_jump_if_reachable (default_label);
4855 enum machine_mode index_mode = SImode;
4856 int index_bits = GET_MODE_BITSIZE (index_mode);
4858 enum machine_mode op_mode;
4860 /* Convert the index to SImode. */
4861 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4862 > GET_MODE_BITSIZE (index_mode))
4864 enum machine_mode omode = TYPE_MODE (index_type);
4865 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4867 /* We must handle the endpoints in the original mode. */
4868 index_expr = build (MINUS_EXPR, index_type,
4869 index_expr, minval);
4870 minval = integer_zero_node;
4871 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4872 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4873 emit_jump_insn (gen_bltu (default_label));
4874 /* Now we can safely truncate. */
4875 index = convert_to_mode (index_mode, index, 0);
4879 if (TYPE_MODE (index_type) != index_mode)
4881 index_expr = convert (type_for_size (index_bits, 0),
4883 index_type = TREE_TYPE (index_expr);
4886 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4889 index = protect_from_queue (index, 0);
4890 do_pending_stack_adjust ();
4892 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4893 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4895 index = copy_to_mode_reg (op_mode, index);
4897 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4899 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4900 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4902 op1 = copy_to_mode_reg (op_mode, op1);
4904 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4906 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4907 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4909 op2 = copy_to_mode_reg (op_mode, op2);
4911 emit_jump_insn (gen_casesi (index, op1, op2,
4912 table_label, default_label));
4916 #ifdef HAVE_tablejump
4917 if (! win && HAVE_tablejump)
4919 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4920 fold (build (MINUS_EXPR, index_type,
4921 index_expr, minval)));
4922 index_type = TREE_TYPE (index_expr);
4923 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4925 index = protect_from_queue (index, 0);
4926 do_pending_stack_adjust ();
4928 do_tablejump (index, TYPE_MODE (index_type),
4929 expand_expr (range, NULL_RTX, VOIDmode, 0),
4930 table_label, default_label);
4937 /* Get table of labels to jump to, in order of case index. */
4939 ncases = TREE_INT_CST_LOW (range) + 1;
4940 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4941 bzero ((char *) labelvec, ncases * sizeof (rtx));
4943 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4945 register HOST_WIDE_INT i
4946 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4951 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4952 if (i + TREE_INT_CST_LOW (orig_minval)
4953 == TREE_INT_CST_LOW (n->high))
4959 /* Fill in the gaps with the default. */
4960 for (i = 0; i < ncases; i++)
4961 if (labelvec[i] == 0)
4962 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4964 /* Output the table */
4965 emit_label (table_label);
4967 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
4968 were an expression, instead of an #ifdef/#ifndef. */
4970 #ifdef CASE_VECTOR_PC_RELATIVE
4974 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
4975 gen_rtx (LABEL_REF, Pmode, table_label),
4976 gen_rtvec_v (ncases, labelvec)));
4978 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
4979 gen_rtvec_v (ncases, labelvec)));
4981 /* If the case insn drops through the table,
4982 after the table we must jump to the default-label.
4983 Otherwise record no drop-through after the table. */
4984 #ifdef CASE_DROPS_THROUGH
4985 emit_jump (default_label);
4991 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
4992 reorder_insns (before_case, get_last_insn (),
4993 thiscase->data.case_stmt.start);
4996 if (thiscase->exit_label)
4997 emit_label (thiscase->exit_label);
4999 POPSTACK (case_stack);
5005 /* Terminate a case statement. EXPR is the original index
5009 bc_expand_end_case (expr)
5012 struct nesting *thiscase = case_stack;
5013 enum bytecode_opcode opcode;
5014 struct bc_label *jump_label;
5015 struct case_node *c;
5017 bc_emit_bytecode (jump);
5018 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5020 #ifdef DEBUG_PRINT_CODE
5021 fputc ('\n', stderr);
5024 /* Now that the size of the jump table is known, emit the actual
5025 indexed jump instruction. */
5026 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5028 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5029 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5030 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5032 bc_emit_bytecode (opcode);
5034 /* Now emit the case instructions literal arguments, in order.
5035 In addition to the value on the stack, it uses:
5036 1. The address of the jump table.
5037 2. The size of the jump table.
5038 3. The default label. */
5040 jump_label = bc_get_bytecode_label ();
5041 bc_emit_bytecode_labelref (jump_label);
5042 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5043 sizeof thiscase->data.case_stmt.num_ranges);
5045 if (thiscase->data.case_stmt.default_label)
5046 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5048 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5050 /* Output the jump table. */
5052 bc_align_bytecode (3 /* PTR_ALIGN */);
5053 bc_emit_bytecode_labeldef (jump_label);
5055 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5056 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5058 opcode = TREE_INT_CST_LOW (c->low);
5059 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5061 opcode = TREE_INT_CST_LOW (c->high);
5062 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5064 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5067 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5068 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5070 bc_emit_bytecode_DI_const (c->low);
5071 bc_emit_bytecode_DI_const (c->high);
5073 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5080 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5082 /* Possibly issue enumeration warnings. */
5084 if (!thiscase->data.case_stmt.default_label
5085 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5086 && TREE_CODE (expr) != INTEGER_CST
5088 check_for_full_enumeration_handling (TREE_TYPE (expr));
5091 #ifdef DEBUG_PRINT_CODE
5092 fputc ('\n', stderr);
5095 POPSTACK (case_stack);
5099 /* Return unique bytecode ID. */
5104 static int bc_uid = 0;
5109 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5112 do_jump_if_equal (op1, op2, label, unsignedp)
5113 rtx op1, op2, label;
5116 if (GET_CODE (op1) == CONST_INT
5117 && GET_CODE (op2) == CONST_INT)
5119 if (INTVAL (op1) == INTVAL (op2))
5124 enum machine_mode mode = GET_MODE (op1);
5125 if (mode == VOIDmode)
5126 mode = GET_MODE (op2);
5127 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5128 emit_jump_insn (gen_beq (label));
5132 /* Not all case values are encountered equally. This function
5133 uses a heuristic to weight case labels, in cases where that
5134 looks like a reasonable thing to do.
5136 Right now, all we try to guess is text, and we establish the
5139 chars above space: 16
5148 If we find any cases in the switch that are not either -1 or in the range
5149 of valid ASCII characters, or are control characters other than those
5150 commonly used with "\", don't treat this switch scanning text.
5152 Return 1 if these nodes are suitable for cost estimation, otherwise
5156 estimate_case_costs (node)
5159 tree min_ascii = build_int_2 (-1, -1);
5160 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5164 /* If we haven't already made the cost table, make it now. Note that the
5165 lower bound of the table is -1, not zero. */
5167 if (cost_table == NULL)
5169 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5170 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5172 for (i = 0; i < 128; i++)
5176 else if (ispunct (i))
5178 else if (iscntrl (i))
5182 cost_table[' '] = 8;
5183 cost_table['\t'] = 4;
5184 cost_table['\0'] = 4;
5185 cost_table['\n'] = 2;
5186 cost_table['\f'] = 1;
5187 cost_table['\v'] = 1;
5188 cost_table['\b'] = 1;
5191 /* See if all the case expressions look like text. It is text if the
5192 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5193 as signed arithmetic since we don't want to ever access cost_table with a
5194 value less than -1. Also check that none of the constants in a range
5195 are strange control characters. */
5197 for (n = node; n; n = n->right)
5199 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5202 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5203 if (cost_table[i] < 0)
5207 /* All interesting values are within the range of interesting
5208 ASCII characters. */
5212 /* Scan an ordered list of case nodes
5213 combining those with consecutive values or ranges.
5215 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5218 group_case_nodes (head)
5221 case_node_ptr node = head;
5225 rtx lb = next_real_insn (label_rtx (node->code_label));
5226 case_node_ptr np = node;
5228 /* Try to group the successors of NODE with NODE. */
5229 while (((np = np->right) != 0)
5230 /* Do they jump to the same place? */
5231 && next_real_insn (label_rtx (np->code_label)) == lb
5232 /* Are their ranges consecutive? */
5233 && tree_int_cst_equal (np->low,
5234 fold (build (PLUS_EXPR,
5235 TREE_TYPE (node->high),
5238 /* An overflow is not consecutive. */
5239 && tree_int_cst_lt (node->high,
5240 fold (build (PLUS_EXPR,
5241 TREE_TYPE (node->high),
5243 integer_one_node))))
5245 node->high = np->high;
5247 /* NP is the first node after NODE which can't be grouped with it.
5248 Delete the nodes in between, and move on to that node. */
5254 /* Take an ordered list of case nodes
5255 and transform them into a near optimal binary tree,
5256 on the assumption that any target code selection value is as
5257 likely as any other.
5259 The transformation is performed by splitting the ordered
5260 list into two equal sections plus a pivot. The parts are
5261 then attached to the pivot as left and right branches. Each
5262 branch is is then transformed recursively. */
5265 balance_case_nodes (head, parent)
5266 case_node_ptr *head;
5267 case_node_ptr parent;
5269 register case_node_ptr np;
5277 register case_node_ptr *npp;
5280 /* Count the number of entries on branch. Also count the ranges. */
5284 if (!tree_int_cst_equal (np->low, np->high))
5288 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5292 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5300 /* Split this list if it is long enough for that to help. */
5305 /* Find the place in the list that bisects the list's total cost,
5306 Here I gets half the total cost. */
5311 /* Skip nodes while their cost does not reach that amount. */
5312 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5313 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5314 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5317 npp = &(*npp)->right;
5322 /* Leave this branch lopsided, but optimize left-hand
5323 side and fill in `parent' fields for right-hand side. */
5325 np->parent = parent;
5326 balance_case_nodes (&np->left, np);
5327 for (; np->right; np = np->right)
5328 np->right->parent = np;
5332 /* If there are just three nodes, split at the middle one. */
5334 npp = &(*npp)->right;
5337 /* Find the place in the list that bisects the list's total cost,
5338 where ranges count as 2.
5339 Here I gets half the total cost. */
5340 i = (i + ranges + 1) / 2;
5343 /* Skip nodes while their cost does not reach that amount. */
5344 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5349 npp = &(*npp)->right;
5354 np->parent = parent;
5357 /* Optimize each of the two split parts. */
5358 balance_case_nodes (&np->left, np);
5359 balance_case_nodes (&np->right, np);
5363 /* Else leave this branch as one level,
5364 but fill in `parent' fields. */
5366 np->parent = parent;
5367 for (; np->right; np = np->right)
5368 np->right->parent = np;
5373 /* Search the parent sections of the case node tree
5374 to see if a test for the lower bound of NODE would be redundant.
5375 INDEX_TYPE is the type of the index expression.
5377 The instructions to generate the case decision tree are
5378 output in the same order as nodes are processed so it is
5379 known that if a parent node checks the range of the current
5380 node minus one that the current node is bounded at its lower
5381 span. Thus the test would be redundant. */
5384 node_has_low_bound (node, index_type)
5389 case_node_ptr pnode;
5391 /* If the lower bound of this node is the lowest value in the index type,
5392 we need not test it. */
5394 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5397 /* If this node has a left branch, the value at the left must be less
5398 than that at this node, so it cannot be bounded at the bottom and
5399 we need not bother testing any further. */
5404 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5405 node->low, integer_one_node));
5407 /* If the subtraction above overflowed, we can't verify anything.
5408 Otherwise, look for a parent that tests our value - 1. */
5410 if (! tree_int_cst_lt (low_minus_one, node->low))
5413 for (pnode = node->parent; pnode; pnode = pnode->parent)
5414 if (tree_int_cst_equal (low_minus_one, pnode->high))
5420 /* Search the parent sections of the case node tree
5421 to see if a test for the upper bound of NODE would be redundant.
5422 INDEX_TYPE is the type of the index expression.
5424 The instructions to generate the case decision tree are
5425 output in the same order as nodes are processed so it is
5426 known that if a parent node checks the range of the current
5427 node plus one that the current node is bounded at its upper
5428 span. Thus the test would be redundant. */
5431 node_has_high_bound (node, index_type)
5436 case_node_ptr pnode;
5438 /* If the upper bound of this node is the highest value in the type
5439 of the index expression, we need not test against it. */
5441 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5444 /* If this node has a right branch, the value at the right must be greater
5445 than that at this node, so it cannot be bounded at the top and
5446 we need not bother testing any further. */
5451 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5452 node->high, integer_one_node));
5454 /* If the addition above overflowed, we can't verify anything.
5455 Otherwise, look for a parent that tests our value + 1. */
5457 if (! tree_int_cst_lt (node->high, high_plus_one))
5460 for (pnode = node->parent; pnode; pnode = pnode->parent)
5461 if (tree_int_cst_equal (high_plus_one, pnode->low))
5467 /* Search the parent sections of the
5468 case node tree to see if both tests for the upper and lower
5469 bounds of NODE would be redundant. */
5472 node_is_bounded (node, index_type)
5476 return (node_has_low_bound (node, index_type)
5477 && node_has_high_bound (node, index_type));
5480 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5483 emit_jump_if_reachable (label)
5486 if (GET_CODE (get_last_insn ()) != BARRIER)
5490 /* Emit step-by-step code to select a case for the value of INDEX.
5491 The thus generated decision tree follows the form of the
5492 case-node binary tree NODE, whose nodes represent test conditions.
5493 INDEX_TYPE is the type of the index of the switch.
5495 Care is taken to prune redundant tests from the decision tree
5496 by detecting any boundary conditions already checked by
5497 emitted rtx. (See node_has_high_bound, node_has_low_bound
5498 and node_is_bounded, above.)
5500 Where the test conditions can be shown to be redundant we emit
5501 an unconditional jump to the target code. As a further
5502 optimization, the subordinates of a tree node are examined to
5503 check for bounded nodes. In this case conditional and/or
5504 unconditional jumps as a result of the boundary check for the
5505 current node are arranged to target the subordinates associated
5506 code for out of bound conditions on the current node node.
5508 We can assume that when control reaches the code generated here,
5509 the index value has already been compared with the parents
5510 of this node, and determined to be on the same side of each parent
5511 as this node is. Thus, if this node tests for the value 51,
5512 and a parent tested for 52, we don't need to consider
5513 the possibility of a value greater than 51. If another parent
5514 tests for the value 50, then this node need not test anything. */
5517 emit_case_nodes (index, node, default_label, index_type)
5523 /* If INDEX has an unsigned type, we must make unsigned branches. */
5524 int unsignedp = TREE_UNSIGNED (index_type);
5525 typedef rtx rtx_function ();
5526 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5527 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5528 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5529 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5530 enum machine_mode mode = GET_MODE (index);
5532 /* See if our parents have already tested everything for us.
5533 If they have, emit an unconditional jump for this node. */
5534 if (node_is_bounded (node, index_type))
5535 emit_jump (label_rtx (node->code_label));
5537 else if (tree_int_cst_equal (node->low, node->high))
5539 /* Node is single valued. First see if the index expression matches
5540 this node and then check our children, if any. */
5542 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5543 label_rtx (node->code_label), unsignedp);
5545 if (node->right != 0 && node->left != 0)
5547 /* This node has children on both sides.
5548 Dispatch to one side or the other
5549 by comparing the index value with this node's value.
5550 If one subtree is bounded, check that one first,
5551 so we can avoid real branches in the tree. */
5553 if (node_is_bounded (node->right, index_type))
5555 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5557 GT, NULL_RTX, mode, unsignedp, 0);
5559 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5560 emit_case_nodes (index, node->left, default_label, index_type);
5563 else if (node_is_bounded (node->left, index_type))
5565 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5567 LT, NULL_RTX, mode, unsignedp, 0);
5568 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5569 emit_case_nodes (index, node->right, default_label, index_type);
5574 /* Neither node is bounded. First distinguish the two sides;
5575 then emit the code for one side at a time. */
5578 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5580 /* See if the value is on the right. */
5581 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5583 GT, NULL_RTX, mode, unsignedp, 0);
5584 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5586 /* Value must be on the left.
5587 Handle the left-hand subtree. */
5588 emit_case_nodes (index, node->left, default_label, index_type);
5589 /* If left-hand subtree does nothing,
5591 emit_jump_if_reachable (default_label);
5593 /* Code branches here for the right-hand subtree. */
5594 expand_label (test_label);
5595 emit_case_nodes (index, node->right, default_label, index_type);
5599 else if (node->right != 0 && node->left == 0)
5601 /* Here we have a right child but no left so we issue conditional
5602 branch to default and process the right child.
5604 Omit the conditional branch to default if we it avoid only one
5605 right child; it costs too much space to save so little time. */
5607 if (node->right->right || node->right->left
5608 || !tree_int_cst_equal (node->right->low, node->right->high))
5610 if (!node_has_low_bound (node, index_type))
5612 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5614 LT, NULL_RTX, mode, unsignedp, 0);
5615 emit_jump_insn ((*gen_blt_pat) (default_label));
5618 emit_case_nodes (index, node->right, default_label, index_type);
5621 /* We cannot process node->right normally
5622 since we haven't ruled out the numbers less than
5623 this node's value. So handle node->right explicitly. */
5624 do_jump_if_equal (index,
5625 expand_expr (node->right->low, NULL_RTX,
5627 label_rtx (node->right->code_label), unsignedp);
5630 else if (node->right == 0 && node->left != 0)
5632 /* Just one subtree, on the left. */
5634 #if 0 /* The following code and comment were formerly part
5635 of the condition here, but they didn't work
5636 and I don't understand what the idea was. -- rms. */
5637 /* If our "most probable entry" is less probable
5638 than the default label, emit a jump to
5639 the default label using condition codes
5640 already lying around. With no right branch,
5641 a branch-greater-than will get us to the default
5644 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5647 if (node->left->left || node->left->right
5648 || !tree_int_cst_equal (node->left->low, node->left->high))
5650 if (!node_has_high_bound (node, index_type))
5652 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5654 GT, NULL_RTX, mode, unsignedp, 0);
5655 emit_jump_insn ((*gen_bgt_pat) (default_label));
5658 emit_case_nodes (index, node->left, default_label, index_type);
5661 /* We cannot process node->left normally
5662 since we haven't ruled out the numbers less than
5663 this node's value. So handle node->left explicitly. */
5664 do_jump_if_equal (index,
5665 expand_expr (node->left->low, NULL_RTX,
5667 label_rtx (node->left->code_label), unsignedp);
5672 /* Node is a range. These cases are very similar to those for a single
5673 value, except that we do not start by testing whether this node
5674 is the one to branch to. */
5676 if (node->right != 0 && node->left != 0)
5678 /* Node has subtrees on both sides.
5679 If the right-hand subtree is bounded,
5680 test for it first, since we can go straight there.
5681 Otherwise, we need to make a branch in the control structure,
5682 then handle the two subtrees. */
5683 tree test_label = 0;
5685 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5687 GT, NULL_RTX, mode, unsignedp, 0);
5689 if (node_is_bounded (node->right, index_type))
5690 /* Right hand node is fully bounded so we can eliminate any
5691 testing and branch directly to the target code. */
5692 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5695 /* Right hand node requires testing.
5696 Branch to a label where we will handle it later. */
5698 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5699 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5702 /* Value belongs to this node or to the left-hand subtree. */
5704 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5705 GE, NULL_RTX, mode, unsignedp, 0);
5706 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5708 /* Handle the left-hand subtree. */
5709 emit_case_nodes (index, node->left, default_label, index_type);
5711 /* If right node had to be handled later, do that now. */
5715 /* If the left-hand subtree fell through,
5716 don't let it fall into the right-hand subtree. */
5717 emit_jump_if_reachable (default_label);
5719 expand_label (test_label);
5720 emit_case_nodes (index, node->right, default_label, index_type);
5724 else if (node->right != 0 && node->left == 0)
5726 /* Deal with values to the left of this node,
5727 if they are possible. */
5728 if (!node_has_low_bound (node, index_type))
5730 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5732 LT, NULL_RTX, mode, unsignedp, 0);
5733 emit_jump_insn ((*gen_blt_pat) (default_label));
5736 /* Value belongs to this node or to the right-hand subtree. */
5738 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5740 LE, NULL_RTX, mode, unsignedp, 0);
5741 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5743 emit_case_nodes (index, node->right, default_label, index_type);
5746 else if (node->right == 0 && node->left != 0)
5748 /* Deal with values to the right of this node,
5749 if they are possible. */
5750 if (!node_has_high_bound (node, index_type))
5752 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5754 GT, NULL_RTX, mode, unsignedp, 0);
5755 emit_jump_insn ((*gen_bgt_pat) (default_label));
5758 /* Value belongs to this node or to the left-hand subtree. */
5760 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5761 GE, NULL_RTX, mode, unsignedp, 0);
5762 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5764 emit_case_nodes (index, node->left, default_label, index_type);
5769 /* Node has no children so we check low and high bounds to remove
5770 redundant tests. Only one of the bounds can exist,
5771 since otherwise this node is bounded--a case tested already. */
5773 if (!node_has_high_bound (node, index_type))
5775 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5777 GT, NULL_RTX, mode, unsignedp, 0);
5778 emit_jump_insn ((*gen_bgt_pat) (default_label));
5781 if (!node_has_low_bound (node, index_type))
5783 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5785 LT, NULL_RTX, mode, unsignedp, 0);
5786 emit_jump_insn ((*gen_blt_pat) (default_label));
5789 emit_jump (label_rtx (node->code_label));
5794 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5795 so that the debugging info will be correct for the unrolled loop. */
5797 /* Indexed by block number, contains a pointer to the N'th block node. */
5799 static tree *block_vector;
5802 find_loop_tree_blocks ()
5804 tree block = DECL_INITIAL (current_function_decl);
5806 /* There first block is for the function body, and does not have
5807 corresponding block notes. Don't include it in the block vector. */
5808 block = BLOCK_SUBBLOCKS (block);
5810 block_vector = identify_blocks (block, get_insns ());
5814 unroll_block_trees ()
5816 tree block = DECL_INITIAL (current_function_decl);
5818 reorder_blocks (block_vector, block, get_insns ());