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);
614 #ifdef POINTERS_EXTEND_UNSIGNED
615 x = convert_memory_address (Pmode, x);
617 emit_indirect_jump (x);
621 /* Handle goto statements and the labels that they can go to. */
623 /* Specify the location in the RTL code of a label LABEL,
624 which is a LABEL_DECL tree node.
626 This is used for the kind of label that the user can jump to with a
627 goto statement, and for alternatives of a switch or case statement.
628 RTL labels generated for loops and conditionals don't go through here;
629 they are generated directly at the RTL level, by other functions below.
631 Note that this has nothing to do with defining label *names*.
632 Languages vary in how they do that and what that even means. */
638 struct label_chain *p;
642 if (! DECL_RTL (label))
643 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
644 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
645 error ("multiply defined label");
649 do_pending_stack_adjust ();
650 emit_label (label_rtx (label));
651 if (DECL_NAME (label))
652 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
654 if (stack_block_stack != 0)
656 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
657 p->next = stack_block_stack->data.block.label_chain;
658 stack_block_stack->data.block.label_chain = p;
663 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
664 from nested functions. */
667 declare_nonlocal_label (label)
670 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
671 LABEL_PRESERVE_P (label_rtx (label)) = 1;
672 if (nonlocal_goto_handler_slot == 0)
674 nonlocal_goto_handler_slot
675 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
676 emit_stack_save (SAVE_NONLOCAL,
677 &nonlocal_goto_stack_level,
678 PREV_INSN (tail_recursion_reentry));
682 /* Generate RTL code for a `goto' statement with target label LABEL.
683 LABEL should be a LABEL_DECL tree node that was or will later be
684 defined with `expand_label'. */
694 expand_goto_internal (label, label_rtx (label), NULL_RTX);
698 /* Check for a nonlocal goto to a containing function. */
699 context = decl_function_context (label);
700 if (context != 0 && context != current_function_decl)
702 struct function *p = find_function_data (context);
703 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
706 p->has_nonlocal_label = 1;
707 current_function_has_nonlocal_goto = 1;
708 LABEL_REF_NONLOCAL_P (label_ref) = 1;
710 /* Copy the rtl for the slots so that they won't be shared in
711 case the virtual stack vars register gets instantiated differently
712 in the parent than in the child. */
714 #if HAVE_nonlocal_goto
715 if (HAVE_nonlocal_goto)
716 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
717 copy_rtx (p->nonlocal_goto_handler_slot),
718 copy_rtx (p->nonlocal_goto_stack_level),
725 /* Restore frame pointer for containing function.
726 This sets the actual hard register used for the frame pointer
727 to the location of the function's incoming static chain info.
728 The non-local goto handler will then adjust it to contain the
729 proper value and reload the argument pointer, if needed. */
730 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
732 /* We have now loaded the frame pointer hardware register with
733 the address of that corresponds to the start of the virtual
734 stack vars. So replace virtual_stack_vars_rtx in all
735 addresses we use with stack_pointer_rtx. */
737 /* Get addr of containing function's current nonlocal goto handler,
738 which will do any cleanups and then jump to the label. */
739 addr = copy_rtx (p->nonlocal_goto_handler_slot);
740 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
741 hard_frame_pointer_rtx));
743 /* Restore the stack pointer. Note this uses fp just restored. */
744 addr = p->nonlocal_goto_stack_level;
746 addr = replace_rtx (copy_rtx (addr),
747 virtual_stack_vars_rtx,
748 hard_frame_pointer_rtx);
750 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
752 /* Put in the static chain register the nonlocal label address. */
753 emit_move_insn (static_chain_rtx, label_ref);
754 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
756 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
757 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
758 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
759 emit_indirect_jump (temp);
763 expand_goto_internal (label, label_rtx (label), NULL_RTX);
766 /* Generate RTL code for a `goto' statement with target label BODY.
767 LABEL should be a LABEL_REF.
768 LAST_INSN, if non-0, is the rtx we should consider as the last
769 insn emitted (for the purposes of cleaning up a return). */
772 expand_goto_internal (body, label, last_insn)
777 struct nesting *block;
780 /* NOTICE! If a bytecode instruction other than `jump' is needed,
781 then the caller has to call bc_expand_goto_internal()
782 directly. This is rather an exceptional case, and there aren't
783 that many places where this is necessary. */
786 expand_goto_internal (body, label, last_insn);
790 if (GET_CODE (label) != CODE_LABEL)
793 /* If label has already been defined, we can tell now
794 whether and how we must alter the stack level. */
796 if (PREV_INSN (label) != 0)
798 /* Find the innermost pending block that contains the label.
799 (Check containment by comparing insn-uids.)
800 Then restore the outermost stack level within that block,
801 and do cleanups of all blocks contained in it. */
802 for (block = block_stack; block; block = block->next)
804 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
806 if (block->data.block.stack_level != 0)
807 stack_level = block->data.block.stack_level;
808 /* Execute the cleanups for blocks we are exiting. */
809 if (block->data.block.cleanups != 0)
811 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
812 do_pending_stack_adjust ();
818 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
819 the stack pointer. This one should be deleted as dead by flow. */
820 clear_pending_stack_adjust ();
821 do_pending_stack_adjust ();
822 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
825 if (body != 0 && DECL_TOO_LATE (body))
826 error ("jump to `%s' invalidly jumps into binding contour",
827 IDENTIFIER_POINTER (DECL_NAME (body)));
829 /* Label not yet defined: may need to put this goto
830 on the fixup list. */
831 else if (! expand_fixup (body, label, last_insn))
833 /* No fixup needed. Record that the label is the target
834 of at least one goto that has no fixup. */
836 TREE_ADDRESSABLE (body) = 1;
842 /* Generate a jump with OPCODE to the given bytecode LABEL which is
843 found within BODY. */
846 bc_expand_goto_internal (opcode, label, body)
847 enum bytecode_opcode opcode;
848 struct bc_label *label;
851 struct nesting *block;
852 int stack_level = -1;
854 /* If the label is defined, adjust the stack as necessary.
855 If it's not defined, we have to push the reference on the
861 /* Find the innermost pending block that contains the label.
862 (Check containment by comparing bytecode uids.) Then restore the
863 outermost stack level within that block. */
865 for (block = block_stack; block; block = block->next)
867 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
869 if (block->data.block.bc_stack_level)
870 stack_level = block->data.block.bc_stack_level;
872 /* Execute the cleanups for blocks we are exiting. */
873 if (block->data.block.cleanups != 0)
875 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
876 do_pending_stack_adjust ();
880 /* Restore the stack level. If we need to adjust the stack, we
881 must do so after the jump, since the jump may depend on
882 what's on the stack. Thus, any stack-modifying conditional
883 jumps (these are the only ones that rely on what's on the
884 stack) go into the fixup list. */
887 && stack_depth != stack_level
890 bc_expand_fixup (opcode, label, stack_level);
893 if (stack_level >= 0)
894 bc_adjust_stack (stack_depth - stack_level);
896 if (body && DECL_BIT_FIELD (body))
897 error ("jump to `%s' invalidly jumps into binding contour",
898 IDENTIFIER_POINTER (DECL_NAME (body)));
900 /* Emit immediate jump */
901 bc_emit_bytecode (opcode);
902 bc_emit_bytecode_labelref (label);
904 #ifdef DEBUG_PRINT_CODE
905 fputc ('\n', stderr);
910 /* Put goto in the fixup list */
911 bc_expand_fixup (opcode, label, stack_level);
914 /* Generate if necessary a fixup for a goto
915 whose target label in tree structure (if any) is TREE_LABEL
916 and whose target in rtl is RTL_LABEL.
918 If LAST_INSN is nonzero, we pretend that the jump appears
919 after insn LAST_INSN instead of at the current point in the insn stream.
921 The fixup will be used later to insert insns just before the goto.
922 Those insns will restore the stack level as appropriate for the
923 target label, and will (in the case of C++) also invoke any object
924 destructors which have to be invoked when we exit the scopes which
925 are exited by the goto.
927 Value is nonzero if a fixup is made. */
930 expand_fixup (tree_label, rtl_label, last_insn)
935 struct nesting *block, *end_block;
937 /* See if we can recognize which block the label will be output in.
938 This is possible in some very common cases.
939 If we succeed, set END_BLOCK to that block.
940 Otherwise, set it to 0. */
943 && (rtl_label == cond_stack->data.cond.endif_label
944 || rtl_label == cond_stack->data.cond.next_label))
945 end_block = cond_stack;
946 /* If we are in a loop, recognize certain labels which
947 are likely targets. This reduces the number of fixups
948 we need to create. */
950 && (rtl_label == loop_stack->data.loop.start_label
951 || rtl_label == loop_stack->data.loop.end_label
952 || rtl_label == loop_stack->data.loop.continue_label))
953 end_block = loop_stack;
957 /* Now set END_BLOCK to the binding level to which we will return. */
961 struct nesting *next_block = end_block->all;
964 /* First see if the END_BLOCK is inside the innermost binding level.
965 If so, then no cleanups or stack levels are relevant. */
966 while (next_block && next_block != block)
967 next_block = next_block->all;
972 /* Otherwise, set END_BLOCK to the innermost binding level
973 which is outside the relevant control-structure nesting. */
974 next_block = block_stack->next;
975 for (block = block_stack; block != end_block; block = block->all)
976 if (block == next_block)
977 next_block = next_block->next;
978 end_block = next_block;
981 /* Does any containing block have a stack level or cleanups?
982 If not, no fixup is needed, and that is the normal case
983 (the only case, for standard C). */
984 for (block = block_stack; block != end_block; block = block->next)
985 if (block->data.block.stack_level != 0
986 || block->data.block.cleanups != 0)
989 if (block != end_block)
991 /* Ok, a fixup is needed. Add a fixup to the list of such. */
992 struct goto_fixup *fixup
993 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
994 /* In case an old stack level is restored, make sure that comes
995 after any pending stack adjust. */
996 /* ?? If the fixup isn't to come at the present position,
997 doing the stack adjust here isn't useful. Doing it with our
998 settings at that location isn't useful either. Let's hope
1001 do_pending_stack_adjust ();
1002 fixup->target = tree_label;
1003 fixup->target_rtl = rtl_label;
1005 /* Create a BLOCK node and a corresponding matched set of
1006 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1007 this point. The notes will encapsulate any and all fixup
1008 code which we might later insert at this point in the insn
1009 stream. Also, the BLOCK node will be the parent (i.e. the
1010 `SUPERBLOCK') of any other BLOCK nodes which we might create
1011 later on when we are expanding the fixup code. */
1014 register rtx original_before_jump
1015 = last_insn ? last_insn : get_last_insn ();
1019 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1020 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1021 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1023 emit_insns_after (fixup->before_jump, original_before_jump);
1026 fixup->block_start_count = block_start_count;
1027 fixup->stack_level = 0;
1028 fixup->cleanup_list_list
1029 = (((block->data.block.outer_cleanups
1031 && block->data.block.outer_cleanups != empty_cleanup_list
1034 || block->data.block.cleanups)
1035 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1036 block->data.block.outer_cleanups)
1038 fixup->next = goto_fixup_chain;
1039 goto_fixup_chain = fixup;
1046 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1047 Make the fixup restore the stack level to STACK_LEVEL. */
1050 bc_expand_fixup (opcode, label, stack_level)
1051 enum bytecode_opcode opcode;
1052 struct bc_label *label;
1055 struct goto_fixup *fixup
1056 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1058 fixup->label = bc_get_bytecode_label ();
1059 fixup->bc_target = label;
1060 fixup->bc_stack_level = stack_level;
1061 fixup->bc_handled = FALSE;
1063 fixup->next = goto_fixup_chain;
1064 goto_fixup_chain = fixup;
1066 /* Insert a jump to the fixup code */
1067 bc_emit_bytecode (opcode);
1068 bc_emit_bytecode_labelref (fixup->label);
1070 #ifdef DEBUG_PRINT_CODE
1071 fputc ('\n', stderr);
1075 /* Expand any needed fixups in the outputmost binding level of the
1076 function. FIRST_INSN is the first insn in the function. */
1079 expand_fixups (first_insn)
1082 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1085 /* When exiting a binding contour, process all pending gotos requiring fixups.
1086 THISBLOCK is the structure that describes the block being exited.
1087 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1088 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1089 FIRST_INSN is the insn that began this contour.
1091 Gotos that jump out of this contour must restore the
1092 stack level and do the cleanups before actually jumping.
1094 DONT_JUMP_IN nonzero means report error there is a jump into this
1095 contour from before the beginning of the contour.
1096 This is also done if STACK_LEVEL is nonzero. */
1099 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1100 struct nesting *thisblock;
1106 register struct goto_fixup *f, *prev;
1108 if (output_bytecode)
1110 /* ??? The second arg is the bc stack level, which is not the same
1111 as STACK_LEVEL. I have no idea what should go here, so I'll
1113 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1117 /* F is the fixup we are considering; PREV is the previous one. */
1118 /* We run this loop in two passes so that cleanups of exited blocks
1119 are run first, and blocks that are exited are marked so
1122 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1124 /* Test for a fixup that is inactive because it is already handled. */
1125 if (f->before_jump == 0)
1127 /* Delete inactive fixup from the chain, if that is easy to do. */
1129 prev->next = f->next;
1131 /* Has this fixup's target label been defined?
1132 If so, we can finalize it. */
1133 else if (PREV_INSN (f->target_rtl) != 0)
1135 register rtx cleanup_insns;
1137 /* Get the first non-label after the label
1138 this goto jumps to. If that's before this scope begins,
1139 we don't have a jump into the scope. */
1140 rtx after_label = f->target_rtl;
1141 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1142 after_label = NEXT_INSN (after_label);
1144 /* If this fixup jumped into this contour from before the beginning
1145 of this contour, report an error. */
1146 /* ??? Bug: this does not detect jumping in through intermediate
1147 blocks that have stack levels or cleanups.
1148 It detects only a problem with the innermost block
1149 around the label. */
1151 && (dont_jump_in || stack_level || cleanup_list)
1152 /* If AFTER_LABEL is 0, it means the jump goes to the end
1153 of the rtl, which means it jumps into this scope. */
1154 && (after_label == 0
1155 || INSN_UID (first_insn) < INSN_UID (after_label))
1156 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1157 && ! DECL_REGISTER (f->target))
1159 error_with_decl (f->target,
1160 "label `%s' used before containing binding contour");
1161 /* Prevent multiple errors for one label. */
1162 DECL_REGISTER (f->target) = 1;
1165 /* We will expand the cleanups into a sequence of their own and
1166 then later on we will attach this new sequence to the insn
1167 stream just ahead of the actual jump insn. */
1171 /* Temporarily restore the lexical context where we will
1172 logically be inserting the fixup code. We do this for the
1173 sake of getting the debugging information right. */
1176 set_block (f->context);
1178 /* Expand the cleanups for blocks this jump exits. */
1179 if (f->cleanup_list_list)
1182 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1183 /* Marked elements correspond to blocks that have been closed.
1184 Do their cleanups. */
1185 if (TREE_ADDRESSABLE (lists)
1186 && TREE_VALUE (lists) != 0)
1188 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1189 /* Pop any pushes done in the cleanups,
1190 in case function is about to return. */
1191 do_pending_stack_adjust ();
1195 /* Restore stack level for the biggest contour that this
1196 jump jumps out of. */
1198 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1200 /* Finish up the sequence containing the insns which implement the
1201 necessary cleanups, and then attach that whole sequence to the
1202 insn stream just ahead of the actual jump insn. Attaching it
1203 at that point insures that any cleanups which are in fact
1204 implicit C++ object destructions (which must be executed upon
1205 leaving the block) appear (to the debugger) to be taking place
1206 in an area of the generated code where the object(s) being
1207 destructed are still "in scope". */
1209 cleanup_insns = get_insns ();
1213 emit_insns_after (cleanup_insns, f->before_jump);
1220 /* For any still-undefined labels, do the cleanups for this block now.
1221 We must do this now since items in the cleanup list may go out
1222 of scope when the block ends. */
1223 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1224 if (f->before_jump != 0
1225 && PREV_INSN (f->target_rtl) == 0
1226 /* Label has still not appeared. If we are exiting a block with
1227 a stack level to restore, that started before the fixup,
1228 mark this stack level as needing restoration
1229 when the fixup is later finalized. */
1231 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1232 means the label is undefined. That's erroneous, but possible. */
1233 && (thisblock->data.block.block_start_count
1234 <= f->block_start_count))
1236 tree lists = f->cleanup_list_list;
1239 for (; lists; lists = TREE_CHAIN (lists))
1240 /* If the following elt. corresponds to our containing block
1241 then the elt. must be for this block. */
1242 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1246 set_block (f->context);
1247 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1248 do_pending_stack_adjust ();
1249 cleanup_insns = get_insns ();
1253 = emit_insns_after (cleanup_insns, f->before_jump);
1255 TREE_VALUE (lists) = 0;
1259 f->stack_level = stack_level;
1264 /* When exiting a binding contour, process all pending gotos requiring fixups.
1265 Note: STACK_DEPTH is not altered.
1267 The arguments are currently not used in the bytecode compiler, but we may
1268 need them one day for languages other than C.
1270 THISBLOCK is the structure that describes the block being exited.
1271 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1272 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1273 FIRST_INSN is the insn that began this contour.
1275 Gotos that jump out of this contour must restore the
1276 stack level and do the cleanups before actually jumping.
1278 DONT_JUMP_IN nonzero means report error there is a jump into this
1279 contour from before the beginning of the contour.
1280 This is also done if STACK_LEVEL is nonzero. */
1283 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1284 struct nesting *thisblock;
1290 register struct goto_fixup *f, *prev;
1291 int saved_stack_depth;
1293 /* F is the fixup we are considering; PREV is the previous one. */
1295 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1297 /* Test for a fixup that is inactive because it is already handled. */
1298 if (f->before_jump == 0)
1300 /* Delete inactive fixup from the chain, if that is easy to do. */
1302 prev->next = f->next;
1305 /* Emit code to restore the stack and continue */
1306 bc_emit_bytecode_labeldef (f->label);
1308 /* Save stack_depth across call, since bc_adjust_stack () will alter
1309 the perceived stack depth via the instructions generated. */
1311 if (f->bc_stack_level >= 0)
1313 saved_stack_depth = stack_depth;
1314 bc_adjust_stack (stack_depth - f->bc_stack_level);
1315 stack_depth = saved_stack_depth;
1318 bc_emit_bytecode (jump);
1319 bc_emit_bytecode_labelref (f->bc_target);
1321 #ifdef DEBUG_PRINT_CODE
1322 fputc ('\n', stderr);
1326 goto_fixup_chain = NULL;
1329 /* Generate RTL for an asm statement (explicit assembler code).
1330 BODY is a STRING_CST node containing the assembler code text,
1331 or an ADDR_EXPR containing a STRING_CST. */
1337 if (output_bytecode)
1339 error ("`asm' is invalid when generating bytecode");
1343 if (TREE_CODE (body) == ADDR_EXPR)
1344 body = TREE_OPERAND (body, 0);
1346 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1347 TREE_STRING_POINTER (body)));
1351 /* Generate RTL for an asm statement with arguments.
1352 STRING is the instruction template.
1353 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1354 Each output or input has an expression in the TREE_VALUE and
1355 a constraint-string in the TREE_PURPOSE.
1356 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1357 that is clobbered by this insn.
1359 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1360 Some elements of OUTPUTS may be replaced with trees representing temporary
1361 values. The caller should copy those temporary values to the originally
1364 VOL nonzero means the insn is volatile; don't optimize it. */
1367 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1368 tree string, outputs, inputs, clobbers;
1373 rtvec argvec, constraints;
1375 int ninputs = list_length (inputs);
1376 int noutputs = list_length (outputs);
1380 /* Vector of RTX's of evaluated output operands. */
1381 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1382 /* The insn we have emitted. */
1385 if (output_bytecode)
1387 error ("`asm' is invalid when generating bytecode");
1391 /* Count the number of meaningful clobbered registers, ignoring what
1392 we would ignore later. */
1394 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1396 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1397 i = decode_reg_name (regname);
1398 if (i >= 0 || i == -4)
1401 error ("unknown register name `%s' in `asm'", regname);
1406 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1408 tree val = TREE_VALUE (tail);
1409 tree type = TREE_TYPE (val);
1414 /* If there's an erroneous arg, emit no insn. */
1415 if (TREE_TYPE (val) == error_mark_node)
1418 /* Make sure constraint has `=' and does not have `+'. */
1421 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1423 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1425 error ("output operand constraint contains `+'");
1428 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '=')
1433 error ("output operand constraint lacks `='");
1437 /* If an output operand is not a decl or indirect ref,
1438 make a temporary to act as an intermediate. Make the asm insn
1439 write into that, then our caller will copy it to the real output
1440 operand. Likewise for promoted variables. */
1442 if (TREE_CODE (val) == INDIRECT_REF
1443 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1444 && ! (GET_CODE (DECL_RTL (val)) == REG
1445 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
1446 output_rtx[i] = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1449 if (TYPE_MODE (type) == BLKmode)
1451 output_rtx[i] = assign_stack_temp (BLKmode,
1452 int_size_in_bytes (type), 0);
1453 MEM_IN_STRUCT_P (output_rtx[i]) = AGGREGATE_TYPE_P (type);
1456 output_rtx[i] = gen_reg_rtx (TYPE_MODE (type));
1458 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1462 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1464 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1468 /* Make vectors for the expression-rtx and constraint strings. */
1470 argvec = rtvec_alloc (ninputs);
1471 constraints = rtvec_alloc (ninputs);
1473 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1474 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1476 MEM_VOLATILE_P (body) = vol;
1478 /* Eval the inputs and put them into ARGVEC.
1479 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1482 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1486 /* If there's an erroneous arg, emit no insn,
1487 because the ASM_INPUT would get VOIDmode
1488 and that could cause a crash in reload. */
1489 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1491 if (TREE_PURPOSE (tail) == NULL_TREE)
1493 error ("hard register `%s' listed as input operand to `asm'",
1494 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1498 /* Make sure constraint has neither `=' nor `+'. */
1500 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1501 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '='
1502 || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1504 error ("input operand constraint contains `%c'",
1505 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1509 XVECEXP (body, 3, i) /* argvec */
1510 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1511 if (CONSTANT_P (XVECEXP (body, 3, i))
1512 && ! general_operand (XVECEXP (body, 3, i),
1513 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1514 XVECEXP (body, 3, i)
1515 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1516 XVECEXP (body, 3, i));
1517 XVECEXP (body, 4, i) /* constraints */
1518 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1519 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1523 /* Protect all the operands from the queue,
1524 now that they have all been evaluated. */
1526 for (i = 0; i < ninputs; i++)
1527 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1529 for (i = 0; i < noutputs; i++)
1530 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1532 /* Now, for each output, construct an rtx
1533 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1534 ARGVEC CONSTRAINTS))
1535 If there is more than one, put them inside a PARALLEL. */
1537 if (noutputs == 1 && nclobbers == 0)
1539 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1540 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1542 else if (noutputs == 0 && nclobbers == 0)
1544 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1545 insn = emit_insn (body);
1551 if (num == 0) num = 1;
1552 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1554 /* For each output operand, store a SET. */
1556 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1558 XVECEXP (body, 0, i)
1559 = gen_rtx (SET, VOIDmode,
1561 gen_rtx (ASM_OPERANDS, VOIDmode,
1562 TREE_STRING_POINTER (string),
1563 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1564 i, argvec, constraints,
1566 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1569 /* If there are no outputs (but there are some clobbers)
1570 store the bare ASM_OPERANDS into the PARALLEL. */
1573 XVECEXP (body, 0, i++) = obody;
1575 /* Store (clobber REG) for each clobbered register specified. */
1577 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1579 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1580 int j = decode_reg_name (regname);
1584 if (j == -3) /* `cc', which is not a register */
1587 if (j == -4) /* `memory', don't cache memory across asm */
1589 XVECEXP (body, 0, i++)
1590 = gen_rtx (CLOBBER, VOIDmode,
1591 gen_rtx (MEM, BLKmode,
1592 gen_rtx (SCRATCH, VOIDmode, 0)));
1596 /* Ignore unknown register, error already signalled. */
1600 /* Use QImode since that's guaranteed to clobber just one reg. */
1601 XVECEXP (body, 0, i++)
1602 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1605 insn = emit_insn (body);
1611 /* Generate RTL to evaluate the expression EXP
1612 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1615 expand_expr_stmt (exp)
1618 if (output_bytecode)
1620 int org_stack_depth = stack_depth;
1622 bc_expand_expr (exp);
1624 /* Restore stack depth */
1625 if (stack_depth < org_stack_depth)
1628 bc_emit_instruction (drop);
1630 last_expr_type = TREE_TYPE (exp);
1634 /* If -W, warn about statements with no side effects,
1635 except for an explicit cast to void (e.g. for assert()), and
1636 except inside a ({...}) where they may be useful. */
1637 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1639 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1640 && !(TREE_CODE (exp) == CONVERT_EXPR
1641 && TREE_TYPE (exp) == void_type_node))
1642 warning_with_file_and_line (emit_filename, emit_lineno,
1643 "statement with no effect");
1644 else if (warn_unused)
1645 warn_if_unused_value (exp);
1648 /* If EXP is of function type and we are expanding statements for
1649 value, convert it to pointer-to-function. */
1650 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1651 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1653 last_expr_type = TREE_TYPE (exp);
1654 if (! flag_syntax_only)
1655 last_expr_value = expand_expr (exp,
1656 (expr_stmts_for_value
1657 ? NULL_RTX : const0_rtx),
1660 /* If all we do is reference a volatile value in memory,
1661 copy it to a register to be sure it is actually touched. */
1662 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1663 && TREE_THIS_VOLATILE (exp))
1665 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1667 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1668 copy_to_reg (last_expr_value);
1671 rtx lab = gen_label_rtx ();
1673 /* Compare the value with itself to reference it. */
1674 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1675 expand_expr (TYPE_SIZE (last_expr_type),
1676 NULL_RTX, VOIDmode, 0),
1678 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1679 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1684 /* If this expression is part of a ({...}) and is in memory, we may have
1685 to preserve temporaries. */
1686 preserve_temp_slots (last_expr_value);
1688 /* Free any temporaries used to evaluate this expression. Any temporary
1689 used as a result of this expression will already have been preserved
1696 /* Warn if EXP contains any computations whose results are not used.
1697 Return 1 if a warning is printed; 0 otherwise. */
1700 warn_if_unused_value (exp)
1703 if (TREE_USED (exp))
1706 switch (TREE_CODE (exp))
1708 case PREINCREMENT_EXPR:
1709 case POSTINCREMENT_EXPR:
1710 case PREDECREMENT_EXPR:
1711 case POSTDECREMENT_EXPR:
1716 case METHOD_CALL_EXPR:
1718 case WITH_CLEANUP_EXPR:
1720 /* We don't warn about COND_EXPR because it may be a useful
1721 construct if either arm contains a side effect. */
1726 /* For a binding, warn if no side effect within it. */
1727 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1730 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1732 case TRUTH_ORIF_EXPR:
1733 case TRUTH_ANDIF_EXPR:
1734 /* In && or ||, warn if 2nd operand has no side effect. */
1735 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1738 if (TREE_NO_UNUSED_WARNING (exp))
1740 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1742 /* Let people do `(foo (), 0)' without a warning. */
1743 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1745 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1749 case NON_LVALUE_EXPR:
1750 /* Don't warn about values cast to void. */
1751 if (TREE_TYPE (exp) == void_type_node)
1753 /* Don't warn about conversions not explicit in the user's program. */
1754 if (TREE_NO_UNUSED_WARNING (exp))
1756 /* Assignment to a cast usually results in a cast of a modify.
1757 Don't complain about that. There can be an arbitrary number of
1758 casts before the modify, so we must loop until we find the first
1759 non-cast expression and then test to see if that is a modify. */
1761 tree tem = TREE_OPERAND (exp, 0);
1763 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1764 tem = TREE_OPERAND (tem, 0);
1766 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1767 || TREE_CODE (tem) == CALL_EXPR)
1773 /* Don't warn about automatic dereferencing of references, since
1774 the user cannot control it. */
1775 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1776 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1777 /* ... fall through ... */
1780 /* Referencing a volatile value is a side effect, so don't warn. */
1781 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1782 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1783 && TREE_THIS_VOLATILE (exp))
1786 warning_with_file_and_line (emit_filename, emit_lineno,
1787 "value computed is not used");
1792 /* Clear out the memory of the last expression evaluated. */
1800 /* Begin a statement which will return a value.
1801 Return the RTL_EXPR for this statement expr.
1802 The caller must save that value and pass it to expand_end_stmt_expr. */
1805 expand_start_stmt_expr ()
1810 /* When generating bytecode just note down the stack depth */
1811 if (output_bytecode)
1812 return (build_int_2 (stack_depth, 0));
1814 /* Make the RTL_EXPR node temporary, not momentary,
1815 so that rtl_expr_chain doesn't become garbage. */
1816 momentary = suspend_momentary ();
1817 t = make_node (RTL_EXPR);
1818 resume_momentary (momentary);
1819 start_sequence_for_rtl_expr (t);
1821 expr_stmts_for_value++;
1825 /* Restore the previous state at the end of a statement that returns a value.
1826 Returns a tree node representing the statement's value and the
1827 insns to compute the value.
1829 The nodes of that expression have been freed by now, so we cannot use them.
1830 But we don't want to do that anyway; the expression has already been
1831 evaluated and now we just want to use the value. So generate a RTL_EXPR
1832 with the proper type and RTL value.
1834 If the last substatement was not an expression,
1835 return something with type `void'. */
1838 expand_end_stmt_expr (t)
1841 if (output_bytecode)
1847 /* At this point, all expressions have been evaluated in order.
1848 However, all expression values have been popped when evaluated,
1849 which means we have to recover the last expression value. This is
1850 the last value removed by means of a `drop' instruction. Instead
1851 of adding code to inhibit dropping the last expression value, it
1852 is here recovered by undoing the `drop'. Since `drop' is
1853 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1856 bc_adjust_stack (-1);
1858 if (!last_expr_type)
1859 last_expr_type = void_type_node;
1861 t = make_node (RTL_EXPR);
1862 TREE_TYPE (t) = last_expr_type;
1863 RTL_EXPR_RTL (t) = NULL;
1864 RTL_EXPR_SEQUENCE (t) = NULL;
1866 /* Don't consider deleting this expr or containing exprs at tree level. */
1867 TREE_THIS_VOLATILE (t) = 1;
1875 if (last_expr_type == 0)
1877 last_expr_type = void_type_node;
1878 last_expr_value = const0_rtx;
1880 else if (last_expr_value == 0)
1881 /* There are some cases where this can happen, such as when the
1882 statement is void type. */
1883 last_expr_value = const0_rtx;
1884 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1885 /* Remove any possible QUEUED. */
1886 last_expr_value = protect_from_queue (last_expr_value, 0);
1890 TREE_TYPE (t) = last_expr_type;
1891 RTL_EXPR_RTL (t) = last_expr_value;
1892 RTL_EXPR_SEQUENCE (t) = get_insns ();
1894 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1898 /* Don't consider deleting this expr or containing exprs at tree level. */
1899 TREE_SIDE_EFFECTS (t) = 1;
1900 /* Propagate volatility of the actual RTL expr. */
1901 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1904 expr_stmts_for_value--;
1909 /* Generate RTL for the start of an if-then. COND is the expression
1910 whose truth should be tested.
1912 If EXITFLAG is nonzero, this conditional is visible to
1913 `exit_something'. */
1916 expand_start_cond (cond, exitflag)
1920 struct nesting *thiscond = ALLOC_NESTING ();
1922 /* Make an entry on cond_stack for the cond we are entering. */
1924 thiscond->next = cond_stack;
1925 thiscond->all = nesting_stack;
1926 thiscond->depth = ++nesting_depth;
1927 thiscond->data.cond.next_label = gen_label_rtx ();
1928 /* Before we encounter an `else', we don't need a separate exit label
1929 unless there are supposed to be exit statements
1930 to exit this conditional. */
1931 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1932 thiscond->data.cond.endif_label = thiscond->exit_label;
1933 cond_stack = thiscond;
1934 nesting_stack = thiscond;
1936 if (output_bytecode)
1937 bc_expand_start_cond (cond, exitflag);
1939 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1942 /* Generate RTL between then-clause and the elseif-clause
1943 of an if-then-elseif-.... */
1946 expand_start_elseif (cond)
1949 if (cond_stack->data.cond.endif_label == 0)
1950 cond_stack->data.cond.endif_label = gen_label_rtx ();
1951 emit_jump (cond_stack->data.cond.endif_label);
1952 emit_label (cond_stack->data.cond.next_label);
1953 cond_stack->data.cond.next_label = gen_label_rtx ();
1954 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1957 /* Generate RTL between the then-clause and the else-clause
1958 of an if-then-else. */
1961 expand_start_else ()
1963 if (cond_stack->data.cond.endif_label == 0)
1964 cond_stack->data.cond.endif_label = gen_label_rtx ();
1966 if (output_bytecode)
1968 bc_expand_start_else ();
1972 emit_jump (cond_stack->data.cond.endif_label);
1973 emit_label (cond_stack->data.cond.next_label);
1974 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
1977 /* After calling expand_start_else, turn this "else" into an "else if"
1978 by providing another condition. */
1981 expand_elseif (cond)
1984 cond_stack->data.cond.next_label = gen_label_rtx ();
1985 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1988 /* Generate RTL for the end of an if-then.
1989 Pop the record for it off of cond_stack. */
1994 struct nesting *thiscond = cond_stack;
1996 if (output_bytecode)
1997 bc_expand_end_cond ();
2000 do_pending_stack_adjust ();
2001 if (thiscond->data.cond.next_label)
2002 emit_label (thiscond->data.cond.next_label);
2003 if (thiscond->data.cond.endif_label)
2004 emit_label (thiscond->data.cond.endif_label);
2007 POPSTACK (cond_stack);
2012 /* Generate code for the start of an if-then. COND is the expression
2013 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2014 is to be visible to exit_something. It is assumed that the caller
2015 has pushed the previous context on the cond stack. */
2018 bc_expand_start_cond (cond, exitflag)
2022 struct nesting *thiscond = cond_stack;
2024 thiscond->data.case_stmt.nominal_type = cond;
2026 thiscond->exit_label = gen_label_rtx ();
2027 bc_expand_expr (cond);
2028 bc_emit_bytecode (xjumpifnot);
2029 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2031 #ifdef DEBUG_PRINT_CODE
2032 fputc ('\n', stderr);
2036 /* Generate the label for the end of an if with
2040 bc_expand_end_cond ()
2042 struct nesting *thiscond = cond_stack;
2044 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2047 /* Generate code for the start of the else- clause of
2051 bc_expand_start_else ()
2053 struct nesting *thiscond = cond_stack;
2055 thiscond->data.cond.endif_label = thiscond->exit_label;
2056 thiscond->exit_label = gen_label_rtx ();
2057 bc_emit_bytecode (jump);
2058 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2060 #ifdef DEBUG_PRINT_CODE
2061 fputc ('\n', stderr);
2064 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2067 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2068 loop should be exited by `exit_something'. This is a loop for which
2069 `expand_continue' will jump to the top of the loop.
2071 Make an entry on loop_stack to record the labels associated with
2075 expand_start_loop (exit_flag)
2078 register struct nesting *thisloop = ALLOC_NESTING ();
2080 /* Make an entry on loop_stack for the loop we are entering. */
2082 thisloop->next = loop_stack;
2083 thisloop->all = nesting_stack;
2084 thisloop->depth = ++nesting_depth;
2085 thisloop->data.loop.start_label = gen_label_rtx ();
2086 thisloop->data.loop.end_label = gen_label_rtx ();
2087 thisloop->data.loop.alt_end_label = 0;
2088 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2089 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2090 loop_stack = thisloop;
2091 nesting_stack = thisloop;
2093 if (output_bytecode)
2095 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2099 do_pending_stack_adjust ();
2101 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2102 emit_label (thisloop->data.loop.start_label);
2107 /* Like expand_start_loop but for a loop where the continuation point
2108 (for expand_continue_loop) will be specified explicitly. */
2111 expand_start_loop_continue_elsewhere (exit_flag)
2114 struct nesting *thisloop = expand_start_loop (exit_flag);
2115 loop_stack->data.loop.continue_label = gen_label_rtx ();
2119 /* Specify the continuation point for a loop started with
2120 expand_start_loop_continue_elsewhere.
2121 Use this at the point in the code to which a continue statement
2125 expand_loop_continue_here ()
2127 if (output_bytecode)
2129 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2132 do_pending_stack_adjust ();
2133 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2134 emit_label (loop_stack->data.loop.continue_label);
2140 bc_expand_end_loop ()
2142 struct nesting *thisloop = loop_stack;
2144 bc_emit_bytecode (jump);
2145 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2147 #ifdef DEBUG_PRINT_CODE
2148 fputc ('\n', stderr);
2151 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2152 POPSTACK (loop_stack);
2157 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2158 Pop the block off of loop_stack. */
2164 register rtx start_label;
2165 rtx last_test_insn = 0;
2168 if (output_bytecode)
2170 bc_expand_end_loop ();
2174 insn = get_last_insn ();
2175 start_label = loop_stack->data.loop.start_label;
2177 /* Mark the continue-point at the top of the loop if none elsewhere. */
2178 if (start_label == loop_stack->data.loop.continue_label)
2179 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2181 do_pending_stack_adjust ();
2183 /* If optimizing, perhaps reorder the loop. If the loop
2184 starts with a conditional exit, roll that to the end
2185 where it will optimize together with the jump back.
2187 We look for the last conditional branch to the exit that we encounter
2188 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2189 branch to the exit first, use it.
2191 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2192 because moving them is not valid. */
2196 ! (GET_CODE (insn) == JUMP_INSN
2197 && GET_CODE (PATTERN (insn)) == SET
2198 && SET_DEST (PATTERN (insn)) == pc_rtx
2199 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2201 /* Scan insns from the top of the loop looking for a qualified
2202 conditional exit. */
2203 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2204 insn = NEXT_INSN (insn))
2206 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2209 if (GET_CODE (insn) == NOTE
2210 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2211 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2214 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2217 if (last_test_insn && num_insns > 30)
2220 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2221 && SET_DEST (PATTERN (insn)) == pc_rtx
2222 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2223 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2224 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2225 == loop_stack->data.loop.end_label)
2226 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2227 == loop_stack->data.loop.alt_end_label)))
2228 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2229 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2230 == loop_stack->data.loop.end_label)
2231 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2232 == loop_stack->data.loop.alt_end_label)))))
2233 last_test_insn = insn;
2235 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2236 && GET_CODE (PATTERN (insn)) == SET
2237 && SET_DEST (PATTERN (insn)) == pc_rtx
2238 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2239 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2240 == loop_stack->data.loop.end_label)
2241 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2242 == loop_stack->data.loop.alt_end_label)))
2243 /* Include BARRIER. */
2244 last_test_insn = NEXT_INSN (insn);
2247 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2249 /* We found one. Move everything from there up
2250 to the end of the loop, and add a jump into the loop
2251 to jump to there. */
2252 register rtx newstart_label = gen_label_rtx ();
2253 register rtx start_move = start_label;
2255 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2256 then we want to move this note also. */
2257 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2258 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2259 == NOTE_INSN_LOOP_CONT))
2260 start_move = PREV_INSN (start_move);
2262 emit_label_after (newstart_label, PREV_INSN (start_move));
2263 reorder_insns (start_move, last_test_insn, get_last_insn ());
2264 emit_jump_insn_after (gen_jump (start_label),
2265 PREV_INSN (newstart_label));
2266 emit_barrier_after (PREV_INSN (newstart_label));
2267 start_label = newstart_label;
2271 emit_jump (start_label);
2272 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2273 emit_label (loop_stack->data.loop.end_label);
2275 POPSTACK (loop_stack);
2280 /* Generate a jump to the current loop's continue-point.
2281 This is usually the top of the loop, but may be specified
2282 explicitly elsewhere. If not currently inside a loop,
2283 return 0 and do nothing; caller will print an error message. */
2286 expand_continue_loop (whichloop)
2287 struct nesting *whichloop;
2291 whichloop = loop_stack;
2294 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2299 /* Generate a jump to exit the current loop. If not currently inside a loop,
2300 return 0 and do nothing; caller will print an error message. */
2303 expand_exit_loop (whichloop)
2304 struct nesting *whichloop;
2308 whichloop = loop_stack;
2311 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2315 /* Generate a conditional jump to exit the current loop if COND
2316 evaluates to zero. If not currently inside a loop,
2317 return 0 and do nothing; caller will print an error message. */
2320 expand_exit_loop_if_false (whichloop, cond)
2321 struct nesting *whichloop;
2326 whichloop = loop_stack;
2329 if (output_bytecode)
2331 bc_expand_expr (cond);
2332 bc_expand_goto_internal (xjumpifnot,
2333 BYTECODE_BC_LABEL (whichloop->exit_label),
2338 /* In order to handle fixups, we actually create a conditional jump
2339 around a unconditional branch to exit the loop. If fixups are
2340 necessary, they go before the unconditional branch. */
2342 rtx label = gen_label_rtx ();
2345 do_jump (cond, NULL_RTX, label);
2346 last_insn = get_last_insn ();
2347 if (GET_CODE (last_insn) == CODE_LABEL)
2348 whichloop->data.loop.alt_end_label = last_insn;
2349 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2357 /* Return non-zero if we should preserve sub-expressions as separate
2358 pseudos. We never do so if we aren't optimizing. We always do so
2359 if -fexpensive-optimizations.
2361 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2362 the loop may still be a small one. */
2365 preserve_subexpressions_p ()
2369 if (flag_expensive_optimizations)
2372 if (optimize == 0 || loop_stack == 0)
2375 insn = get_last_insn_anywhere ();
2378 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2379 < n_non_fixed_regs * 3));
2383 /* Generate a jump to exit the current loop, conditional, binding contour
2384 or case statement. Not all such constructs are visible to this function,
2385 only those started with EXIT_FLAG nonzero. Individual languages use
2386 the EXIT_FLAG parameter to control which kinds of constructs you can
2389 If not currently inside anything that can be exited,
2390 return 0 and do nothing; caller will print an error message. */
2393 expand_exit_something ()
2397 for (n = nesting_stack; n; n = n->all)
2398 if (n->exit_label != 0)
2400 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2407 /* Generate RTL to return from the current function, with no value.
2408 (That is, we do not do anything about returning any value.) */
2411 expand_null_return ()
2413 struct nesting *block = block_stack;
2416 if (output_bytecode)
2418 bc_emit_instruction (ret);
2422 /* Does any pending block have cleanups? */
2424 while (block && block->data.block.cleanups == 0)
2425 block = block->next;
2427 /* If yes, use a goto to return, since that runs cleanups. */
2429 expand_null_return_1 (last_insn, block != 0);
2432 /* Generate RTL to return from the current function, with value VAL. */
2435 expand_value_return (val)
2438 struct nesting *block = block_stack;
2439 rtx last_insn = get_last_insn ();
2440 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2442 /* Copy the value to the return location
2443 unless it's already there. */
2445 if (return_reg != val)
2447 #ifdef PROMOTE_FUNCTION_RETURN
2448 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2449 int unsignedp = TREE_UNSIGNED (type);
2450 enum machine_mode mode
2451 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2454 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2455 convert_move (return_reg, val, unsignedp);
2458 emit_move_insn (return_reg, val);
2460 if (GET_CODE (return_reg) == REG
2461 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2462 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2464 /* Does any pending block have cleanups? */
2466 while (block && block->data.block.cleanups == 0)
2467 block = block->next;
2469 /* If yes, use a goto to return, since that runs cleanups.
2470 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2472 expand_null_return_1 (last_insn, block != 0);
2475 /* Output a return with no value. If LAST_INSN is nonzero,
2476 pretend that the return takes place after LAST_INSN.
2477 If USE_GOTO is nonzero then don't use a return instruction;
2478 go to the return label instead. This causes any cleanups
2479 of pending blocks to be executed normally. */
2482 expand_null_return_1 (last_insn, use_goto)
2486 rtx end_label = cleanup_label ? cleanup_label : return_label;
2488 clear_pending_stack_adjust ();
2489 do_pending_stack_adjust ();
2492 /* PCC-struct return always uses an epilogue. */
2493 if (current_function_returns_pcc_struct || use_goto)
2496 end_label = return_label = gen_label_rtx ();
2497 expand_goto_internal (NULL_TREE, end_label, last_insn);
2501 /* Otherwise output a simple return-insn if one is available,
2502 unless it won't do the job. */
2504 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2506 emit_jump_insn (gen_return ());
2512 /* Otherwise jump to the epilogue. */
2513 expand_goto_internal (NULL_TREE, end_label, last_insn);
2516 /* Generate RTL to evaluate the expression RETVAL and return it
2517 from the current function. */
2520 expand_return (retval)
2523 /* If there are any cleanups to be performed, then they will
2524 be inserted following LAST_INSN. It is desirable
2525 that the last_insn, for such purposes, should be the
2526 last insn before computing the return value. Otherwise, cleanups
2527 which call functions can clobber the return value. */
2528 /* ??? rms: I think that is erroneous, because in C++ it would
2529 run destructors on variables that might be used in the subsequent
2530 computation of the return value. */
2532 register rtx val = 0;
2536 struct nesting *block;
2538 /* Bytecode returns are quite simple, just leave the result on the
2539 arithmetic stack. */
2540 if (output_bytecode)
2542 bc_expand_expr (retval);
2543 bc_emit_instruction (ret);
2547 /* If function wants no value, give it none. */
2548 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2550 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2552 expand_null_return ();
2556 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2557 /* This is not sufficient. We also need to watch for cleanups of the
2558 expression we are about to expand. Unfortunately, we cannot know
2559 if it has cleanups until we expand it, and we want to change how we
2560 expand it depending upon if we need cleanups. We can't win. */
2562 cleanups = any_pending_cleanups (1);
2567 if (TREE_CODE (retval) == RESULT_DECL)
2568 retval_rhs = retval;
2569 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2570 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2571 retval_rhs = TREE_OPERAND (retval, 1);
2572 else if (TREE_TYPE (retval) == void_type_node)
2573 /* Recognize tail-recursive call to void function. */
2574 retval_rhs = retval;
2576 retval_rhs = NULL_TREE;
2578 /* Only use `last_insn' if there are cleanups which must be run. */
2579 if (cleanups || cleanup_label != 0)
2580 last_insn = get_last_insn ();
2582 /* Distribute return down conditional expr if either of the sides
2583 may involve tail recursion (see test below). This enhances the number
2584 of tail recursions we see. Don't do this always since it can produce
2585 sub-optimal code in some cases and we distribute assignments into
2586 conditional expressions when it would help. */
2588 if (optimize && retval_rhs != 0
2589 && frame_offset == 0
2590 && TREE_CODE (retval_rhs) == COND_EXPR
2591 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2592 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2594 rtx label = gen_label_rtx ();
2597 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2598 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2599 DECL_RESULT (current_function_decl),
2600 TREE_OPERAND (retval_rhs, 1));
2601 TREE_SIDE_EFFECTS (expr) = 1;
2602 expand_return (expr);
2605 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2606 DECL_RESULT (current_function_decl),
2607 TREE_OPERAND (retval_rhs, 2));
2608 TREE_SIDE_EFFECTS (expr) = 1;
2609 expand_return (expr);
2613 /* For tail-recursive call to current function,
2614 just jump back to the beginning.
2615 It's unsafe if any auto variable in this function
2616 has its address taken; for simplicity,
2617 require stack frame to be empty. */
2618 if (optimize && retval_rhs != 0
2619 && frame_offset == 0
2620 && TREE_CODE (retval_rhs) == CALL_EXPR
2621 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2622 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2623 /* Finish checking validity, and if valid emit code
2624 to set the argument variables for the new call. */
2625 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2626 DECL_ARGUMENTS (current_function_decl)))
2628 if (tail_recursion_label == 0)
2630 tail_recursion_label = gen_label_rtx ();
2631 emit_label_after (tail_recursion_label,
2632 tail_recursion_reentry);
2635 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2640 /* This optimization is safe if there are local cleanups
2641 because expand_null_return takes care of them.
2642 ??? I think it should also be safe when there is a cleanup label,
2643 because expand_null_return takes care of them, too.
2644 Any reason why not? */
2645 if (HAVE_return && cleanup_label == 0
2646 && ! current_function_returns_pcc_struct
2647 && BRANCH_COST <= 1)
2649 /* If this is return x == y; then generate
2650 if (x == y) return 1; else return 0;
2651 if we can do it with explicit return insns and
2652 branches are cheap. */
2654 switch (TREE_CODE (retval_rhs))
2662 case TRUTH_ANDIF_EXPR:
2663 case TRUTH_ORIF_EXPR:
2664 case TRUTH_AND_EXPR:
2666 case TRUTH_NOT_EXPR:
2667 case TRUTH_XOR_EXPR:
2668 op0 = gen_label_rtx ();
2669 jumpifnot (retval_rhs, op0);
2670 expand_value_return (const1_rtx);
2672 expand_value_return (const0_rtx);
2676 #endif /* HAVE_return */
2678 /* If the result is an aggregate that is being returned in one (or more)
2679 registers, load the registers here. The compiler currently can't handle
2680 copying a BLKmode value into registers. We could put this code in a
2681 more general area (for use by everyone instead of just function
2682 call/return), but until this feature is generally usable it is kept here
2683 (and in expand_call). */
2686 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2687 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2690 int big_endian_correction = 0;
2691 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2692 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2693 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2694 rtx result_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2695 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2696 enum machine_mode tmpmode;
2698 /* Structures smaller than a word are aligned to the least significant
2699 byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we
2700 must skip the empty high order bytes when calculating the bit
2702 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
2703 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
2705 for (i = 0; i < n_regs; i++)
2707 rtx reg = gen_reg_rtx (word_mode);
2708 rtx word = operand_subword_force (result_val, i, BLKmode);
2709 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2712 result_pseudos[i] = reg;
2714 /* Clobber REG and move each partword into it. Ensure we don't
2715 go past the end of the structure. Note that the loop below
2716 works because we've already verified that padding and
2717 endianness are compatable. */
2718 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
2721 bitpos < BITS_PER_WORD && bytes > 0;
2722 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
2724 int xbitpos = bitpos + big_endian_correction;
2726 store_bit_field (reg, bitsize, xbitpos, word_mode,
2727 extract_bit_field (word, bitsize, bitpos, 1,
2728 NULL_RTX, word_mode,
2730 bitsize / BITS_PER_UNIT,
2732 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2736 /* Now that the value is in pseudos, copy it to the result reg(s). */
2739 for (i = 0; i < n_regs; i++)
2740 emit_move_insn (gen_rtx (REG, word_mode, REGNO (result_reg) + i),
2743 /* Find the smallest integer mode large enough to hold the
2744 entire structure and use that mode instead of BLKmode
2745 on the USE insn for the return register. */
2746 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2747 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2748 tmpmode != MAX_MACHINE_MODE;
2749 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2751 /* Have we found a large enough mode? */
2752 if (GET_MODE_SIZE (tmpmode) >= bytes)
2756 /* No suitable mode found. */
2757 if (tmpmode == MAX_MACHINE_MODE)
2760 PUT_MODE (result_reg, tmpmode);
2762 expand_value_return (result_reg);
2766 && TREE_TYPE (retval_rhs) != void_type_node
2767 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2769 /* Calculate the return value into a pseudo reg. */
2770 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2772 /* All temporaries have now been used. */
2774 /* Return the calculated value, doing cleanups first. */
2775 expand_value_return (val);
2779 /* No cleanups or no hard reg used;
2780 calculate value into hard return reg. */
2781 expand_expr (retval, const0_rtx, VOIDmode, 0);
2784 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2788 /* Return 1 if the end of the generated RTX is not a barrier.
2789 This means code already compiled can drop through. */
2792 drop_through_at_end_p ()
2794 rtx insn = get_last_insn ();
2795 while (insn && GET_CODE (insn) == NOTE)
2796 insn = PREV_INSN (insn);
2797 return insn && GET_CODE (insn) != BARRIER;
2800 /* Emit code to alter this function's formal parms for a tail-recursive call.
2801 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2802 FORMALS is the chain of decls of formals.
2803 Return 1 if this can be done;
2804 otherwise return 0 and do not emit any code. */
2807 tail_recursion_args (actuals, formals)
2808 tree actuals, formals;
2810 register tree a = actuals, f = formals;
2812 register rtx *argvec;
2814 /* Check that number and types of actuals are compatible
2815 with the formals. This is not always true in valid C code.
2816 Also check that no formal needs to be addressable
2817 and that all formals are scalars. */
2819 /* Also count the args. */
2821 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2823 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2825 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2828 if (a != 0 || f != 0)
2831 /* Compute all the actuals. */
2833 argvec = (rtx *) alloca (i * sizeof (rtx));
2835 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2836 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2838 /* Find which actual values refer to current values of previous formals.
2839 Copy each of them now, before any formal is changed. */
2841 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2845 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2846 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2847 { copy = 1; break; }
2849 argvec[i] = copy_to_reg (argvec[i]);
2852 /* Store the values of the actuals into the formals. */
2854 for (f = formals, a = actuals, i = 0; f;
2855 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2857 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2858 emit_move_insn (DECL_RTL (f), argvec[i]);
2860 convert_move (DECL_RTL (f), argvec[i],
2861 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2868 /* Generate the RTL code for entering a binding contour.
2869 The variables are declared one by one, by calls to `expand_decl'.
2871 EXIT_FLAG is nonzero if this construct should be visible to
2872 `exit_something'. */
2875 expand_start_bindings (exit_flag)
2878 struct nesting *thisblock = ALLOC_NESTING ();
2879 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2881 /* Make an entry on block_stack for the block we are entering. */
2883 thisblock->next = block_stack;
2884 thisblock->all = nesting_stack;
2885 thisblock->depth = ++nesting_depth;
2886 thisblock->data.block.stack_level = 0;
2887 thisblock->data.block.cleanups = 0;
2888 thisblock->data.block.function_call_count = 0;
2892 if (block_stack->data.block.cleanups == NULL_TREE
2893 && (block_stack->data.block.outer_cleanups == NULL_TREE
2894 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2895 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2897 thisblock->data.block.outer_cleanups
2898 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2899 block_stack->data.block.outer_cleanups);
2902 thisblock->data.block.outer_cleanups = 0;
2906 && !(block_stack->data.block.cleanups == NULL_TREE
2907 && block_stack->data.block.outer_cleanups == NULL_TREE))
2908 thisblock->data.block.outer_cleanups
2909 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2910 block_stack->data.block.outer_cleanups);
2912 thisblock->data.block.outer_cleanups = 0;
2914 thisblock->data.block.label_chain = 0;
2915 thisblock->data.block.innermost_stack_block = stack_block_stack;
2916 thisblock->data.block.first_insn = note;
2917 thisblock->data.block.block_start_count = ++block_start_count;
2918 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2919 block_stack = thisblock;
2920 nesting_stack = thisblock;
2922 if (!output_bytecode)
2924 /* Make a new level for allocating stack slots. */
2929 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2930 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2934 remember_end_note (block)
2935 register tree block;
2937 BLOCK_END_NOTE (block) = last_block_end_note;
2938 last_block_end_note = NULL_RTX;
2941 /* Generate RTL code to terminate a binding contour.
2942 VARS is the chain of VAR_DECL nodes
2943 for the variables bound in this contour.
2944 MARK_ENDS is nonzero if we should put a note at the beginning
2945 and end of this binding contour.
2947 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2948 (That is true automatically if the contour has a saved stack level.) */
2951 expand_end_bindings (vars, mark_ends, dont_jump_in)
2956 register struct nesting *thisblock = block_stack;
2959 if (output_bytecode)
2961 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
2966 for (decl = vars; decl; decl = TREE_CHAIN (decl))
2967 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
2968 && ! DECL_IN_SYSTEM_HEADER (decl))
2969 warning_with_decl (decl, "unused variable `%s'");
2971 if (thisblock->exit_label)
2973 do_pending_stack_adjust ();
2974 emit_label (thisblock->exit_label);
2977 /* If necessary, make a handler for nonlocal gotos taking
2978 place in the function calls in this block. */
2979 if (function_call_count != thisblock->data.block.function_call_count
2981 /* Make handler for outermost block
2982 if there were any nonlocal gotos to this function. */
2983 && (thisblock->next == 0 ? current_function_has_nonlocal_label
2984 /* Make handler for inner block if it has something
2985 special to do when you jump out of it. */
2986 : (thisblock->data.block.cleanups != 0
2987 || thisblock->data.block.stack_level != 0)))
2990 rtx afterward = gen_label_rtx ();
2991 rtx handler_label = gen_label_rtx ();
2992 rtx save_receiver = gen_reg_rtx (Pmode);
2995 /* Don't let jump_optimize delete the handler. */
2996 LABEL_PRESERVE_P (handler_label) = 1;
2998 /* Record the handler address in the stack slot for that purpose,
2999 during this block, saving and restoring the outer value. */
3000 if (thisblock->next != 0)
3002 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3005 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3006 insns = get_insns ();
3008 emit_insns_before (insns, thisblock->data.block.first_insn);
3012 emit_move_insn (nonlocal_goto_handler_slot,
3013 gen_rtx (LABEL_REF, Pmode, handler_label));
3014 insns = get_insns ();
3016 emit_insns_before (insns, thisblock->data.block.first_insn);
3018 /* Jump around the handler; it runs only when specially invoked. */
3019 emit_jump (afterward);
3020 emit_label (handler_label);
3022 #ifdef HAVE_nonlocal_goto
3023 if (! HAVE_nonlocal_goto)
3025 /* First adjust our frame pointer to its actual value. It was
3026 previously set to the start of the virtual area corresponding to
3027 the stacked variables when we branched here and now needs to be
3028 adjusted to the actual hardware fp value.
3030 Assignments are to virtual registers are converted by
3031 instantiate_virtual_regs into the corresponding assignment
3032 to the underlying register (fp in this case) that makes
3033 the original assignment true.
3034 So the following insn will actually be
3035 decrementing fp by STARTING_FRAME_OFFSET. */
3036 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3038 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3039 if (fixed_regs[ARG_POINTER_REGNUM])
3041 #ifdef ELIMINABLE_REGS
3042 /* If the argument pointer can be eliminated in favor of the
3043 frame pointer, we don't need to restore it. We assume here
3044 that if such an elimination is present, it can always be used.
3045 This is the case on all known machines; if we don't make this
3046 assumption, we do unnecessary saving on many machines. */
3047 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3050 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3051 if (elim_regs[i].from == ARG_POINTER_REGNUM
3052 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3055 if (i == sizeof elim_regs / sizeof elim_regs [0])
3058 /* Now restore our arg pointer from the address at which it
3059 was saved in our stack frame.
3060 If there hasn't be space allocated for it yet, make
3062 if (arg_pointer_save_area == 0)
3063 arg_pointer_save_area
3064 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3065 emit_move_insn (virtual_incoming_args_rtx,
3066 /* We need a pseudo here, or else
3067 instantiate_virtual_regs_1 complains. */
3068 copy_to_reg (arg_pointer_save_area));
3073 /* The handler expects the desired label address in the static chain
3074 register. It tests the address and does an appropriate jump
3075 to whatever label is desired. */
3076 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3077 /* Skip any labels we shouldn't be able to jump to from here. */
3078 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3080 rtx not_this = gen_label_rtx ();
3081 rtx this = gen_label_rtx ();
3082 do_jump_if_equal (static_chain_rtx,
3083 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3085 emit_jump (not_this);
3087 expand_goto (TREE_VALUE (link));
3088 emit_label (not_this);
3090 /* If label is not recognized, abort. */
3091 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3093 emit_label (afterward);
3096 /* Don't allow jumping into a block that has cleanups or a stack level. */
3098 || thisblock->data.block.stack_level != 0
3099 || thisblock->data.block.cleanups != 0)
3101 struct label_chain *chain;
3103 /* Any labels in this block are no longer valid to go to.
3104 Mark them to cause an error message. */
3105 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3107 DECL_TOO_LATE (chain->label) = 1;
3108 /* If any goto without a fixup came to this label,
3109 that must be an error, because gotos without fixups
3110 come from outside all saved stack-levels and all cleanups. */
3111 if (TREE_ADDRESSABLE (chain->label))
3112 error_with_decl (chain->label,
3113 "label `%s' used before containing binding contour");
3117 /* Restore stack level in effect before the block
3118 (only if variable-size objects allocated). */
3119 /* Perform any cleanups associated with the block. */
3121 if (thisblock->data.block.stack_level != 0
3122 || thisblock->data.block.cleanups != 0)
3124 /* Only clean up here if this point can actually be reached. */
3125 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3127 /* Don't let cleanups affect ({...}) constructs. */
3128 int old_expr_stmts_for_value = expr_stmts_for_value;
3129 rtx old_last_expr_value = last_expr_value;
3130 tree old_last_expr_type = last_expr_type;
3131 expr_stmts_for_value = 0;
3133 /* Do the cleanups. */
3134 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3136 do_pending_stack_adjust ();
3138 expr_stmts_for_value = old_expr_stmts_for_value;
3139 last_expr_value = old_last_expr_value;
3140 last_expr_type = old_last_expr_type;
3142 /* Restore the stack level. */
3144 if (reachable && thisblock->data.block.stack_level != 0)
3146 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3147 thisblock->data.block.stack_level, NULL_RTX);
3148 if (nonlocal_goto_handler_slot != 0)
3149 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3153 /* Any gotos out of this block must also do these things.
3154 Also report any gotos with fixups that came to labels in this
3156 fixup_gotos (thisblock,
3157 thisblock->data.block.stack_level,
3158 thisblock->data.block.cleanups,
3159 thisblock->data.block.first_insn,
3163 /* Mark the beginning and end of the scope if requested.
3164 We do this now, after running cleanups on the variables
3165 just going out of scope, so they are in scope for their cleanups. */
3168 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3170 /* Get rid of the beginning-mark if we don't make an end-mark. */
3171 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3173 /* If doing stupid register allocation, make sure lives of all
3174 register variables declared here extend thru end of scope. */
3177 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3179 rtx rtl = DECL_RTL (decl);
3180 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3184 /* Restore block_stack level for containing block. */
3186 stack_block_stack = thisblock->data.block.innermost_stack_block;
3187 POPSTACK (block_stack);
3189 /* Pop the stack slot nesting and free any slots at this level. */
3194 /* End a binding contour.
3195 VARS is the chain of VAR_DECL nodes for the variables bound
3196 in this contour. MARK_ENDS is nonzer if we should put a note
3197 at the beginning and end of this binding contour.
3198 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3202 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3207 struct nesting *thisbind = nesting_stack;
3211 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3212 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3213 warning_with_decl (decl, "unused variable `%s'");
3215 if (thisbind->exit_label)
3216 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3218 /* Pop block/bindings off stack */
3219 POPSTACK (block_stack);
3222 /* Generate RTL for the automatic variable declaration DECL.
3223 (Other kinds of declarations are simply ignored if seen here.)
3224 CLEANUP is an expression to be executed at exit from this binding contour;
3225 for example, in C++, it might call the destructor for this variable.
3227 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3228 either before or after calling `expand_decl' but before compiling
3229 any subsequent expressions. This is because CLEANUP may be expanded
3230 more than once, on different branches of execution.
3231 For the same reason, CLEANUP may not contain a CALL_EXPR
3232 except as its topmost node--else `preexpand_calls' would get confused.
3234 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3235 that is not associated with any particular variable.
3237 There is no special support here for C++ constructors.
3238 They should be handled by the proper code in DECL_INITIAL. */
3244 struct nesting *thisblock = block_stack;
3247 if (output_bytecode)
3249 bc_expand_decl (decl, 0);
3253 type = TREE_TYPE (decl);
3255 /* Only automatic variables need any expansion done.
3256 Static and external variables, and external functions,
3257 will be handled by `assemble_variable' (called from finish_decl).
3258 TYPE_DECL and CONST_DECL require nothing.
3259 PARM_DECLs are handled in `assign_parms'. */
3261 if (TREE_CODE (decl) != VAR_DECL)
3263 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3266 /* Create the RTL representation for the variable. */
3268 if (type == error_mark_node)
3269 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3270 else if (DECL_SIZE (decl) == 0)
3271 /* Variable with incomplete type. */
3273 if (DECL_INITIAL (decl) == 0)
3274 /* Error message was already done; now avoid a crash. */
3275 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3277 /* An initializer is going to decide the size of this array.
3278 Until we know the size, represent its address with a reg. */
3279 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3280 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3282 else if (DECL_MODE (decl) != BLKmode
3283 /* If -ffloat-store, don't put explicit float vars
3285 && !(flag_float_store
3286 && TREE_CODE (type) == REAL_TYPE)
3287 && ! TREE_THIS_VOLATILE (decl)
3288 && ! TREE_ADDRESSABLE (decl)
3289 && (DECL_REGISTER (decl) || ! obey_regdecls))
3291 /* Automatic variable that can go in a register. */
3292 int unsignedp = TREE_UNSIGNED (type);
3293 enum machine_mode reg_mode
3294 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3296 if (TREE_CODE (type) == COMPLEX_TYPE)
3298 rtx realpart, imagpart;
3299 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3301 /* For a complex type variable, make a CONCAT of two pseudos
3302 so that the real and imaginary parts
3303 can be allocated separately. */
3304 realpart = gen_reg_rtx (partmode);
3305 REG_USERVAR_P (realpart) = 1;
3306 imagpart = gen_reg_rtx (partmode);
3307 REG_USERVAR_P (imagpart) = 1;
3308 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3312 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3313 if (TREE_CODE (type) == POINTER_TYPE)
3314 mark_reg_pointer (DECL_RTL (decl));
3315 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3318 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3320 /* Variable of fixed size that goes on the stack. */
3324 /* If we previously made RTL for this decl, it must be an array
3325 whose size was determined by the initializer.
3326 The old address was a register; set that register now
3327 to the proper address. */
3328 if (DECL_RTL (decl) != 0)
3330 if (GET_CODE (DECL_RTL (decl)) != MEM
3331 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3333 oldaddr = XEXP (DECL_RTL (decl), 0);
3337 = assign_stack_temp (DECL_MODE (decl),
3338 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3339 + BITS_PER_UNIT - 1)
3342 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3344 /* Set alignment we actually gave this decl. */
3345 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3346 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3350 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3351 if (addr != oldaddr)
3352 emit_move_insn (oldaddr, addr);
3355 /* If this is a memory ref that contains aggregate components,
3356 mark it as such for cse and loop optimize. */
3357 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3359 /* If this is in memory because of -ffloat-store,
3360 set the volatile bit, to prevent optimizations from
3361 undoing the effects. */
3362 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3363 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3367 /* Dynamic-size object: must push space on the stack. */
3371 /* Record the stack pointer on entry to block, if have
3372 not already done so. */
3373 if (thisblock->data.block.stack_level == 0)
3375 do_pending_stack_adjust ();
3376 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3377 &thisblock->data.block.stack_level,
3378 thisblock->data.block.first_insn);
3379 stack_block_stack = thisblock;
3382 /* Compute the variable's size, in bytes. */
3383 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3385 size_int (BITS_PER_UNIT)),
3386 NULL_RTX, VOIDmode, 0);
3389 /* Allocate space on the stack for the variable. */
3390 address = allocate_dynamic_stack_space (size, NULL_RTX,
3393 /* Reference the variable indirect through that rtx. */
3394 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3396 /* If this is a memory ref that contains aggregate components,
3397 mark it as such for cse and loop optimize. */
3398 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3400 /* Indicate the alignment we actually gave this variable. */
3401 #ifdef STACK_BOUNDARY
3402 DECL_ALIGN (decl) = STACK_BOUNDARY;
3404 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3408 if (TREE_THIS_VOLATILE (decl))
3409 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3410 #if 0 /* A variable is not necessarily unchanging
3411 just because it is const. RTX_UNCHANGING_P
3412 means no change in the function,
3413 not merely no change in the variable's scope.
3414 It is correct to set RTX_UNCHANGING_P if the variable's scope
3415 is the whole function. There's no convenient way to test that. */
3416 if (TREE_READONLY (decl))
3417 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3420 /* If doing stupid register allocation, make sure life of any
3421 register variable starts here, at the start of its scope. */
3424 use_variable (DECL_RTL (decl));
3428 /* Generate code for the automatic variable declaration DECL. For
3429 most variables this just means we give it a stack offset. The
3430 compiler sometimes emits cleanups without variables and we will
3431 have to deal with those too. */
3434 bc_expand_decl (decl, cleanup)
3442 /* A cleanup with no variable. */
3449 /* Only auto variables need any work. */
3450 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3453 type = TREE_TYPE (decl);
3455 if (type == error_mark_node)
3456 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3458 else if (DECL_SIZE (decl) == 0)
3460 /* Variable with incomplete type. The stack offset herein will be
3461 fixed later in expand_decl_init (). */
3462 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3464 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3466 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3470 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3473 /* Emit code to perform the initialization of a declaration DECL. */
3476 expand_decl_init (decl)
3479 int was_used = TREE_USED (decl);
3481 if (output_bytecode)
3483 bc_expand_decl_init (decl);
3487 /* If this is a CONST_DECL, we don't have to generate any code, but
3488 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3489 to be set while in the obstack containing the constant. If we don't
3490 do this, we can lose if we have functions nested three deep and the middle
3491 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3492 the innermost function is the first to expand that STRING_CST. */
3493 if (TREE_CODE (decl) == CONST_DECL)
3495 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3496 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3497 EXPAND_INITIALIZER);
3501 if (TREE_STATIC (decl))
3504 /* Compute and store the initial value now. */
3506 if (DECL_INITIAL (decl) == error_mark_node)
3508 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3509 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3510 || code == POINTER_TYPE)
3511 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3515 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3517 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3518 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3522 /* Don't let the initialization count as "using" the variable. */
3523 TREE_USED (decl) = was_used;
3525 /* Free any temporaries we made while initializing the decl. */
3529 /* Expand initialization for variable-sized types. Allocate array
3530 using newlocalSI and set local variable, which is a pointer to the
3534 bc_expand_variable_local_init (decl)
3537 /* Evaluate size expression and coerce to SI */
3538 bc_expand_expr (DECL_SIZE (decl));
3540 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3541 no coercion is necessary (?) */
3543 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3544 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3546 /* Emit code to allocate array */
3547 bc_emit_instruction (newlocalSI);
3549 /* Store array pointer in local variable. This is the only instance
3550 where we actually want the address of the pointer to the
3551 variable-size block, rather than the pointer itself. We avoid
3552 using expand_address() since that would cause the pointer to be
3553 pushed rather than its address. Hence the hard-coded reference;
3554 notice also that the variable is always local (no global
3555 variable-size type variables). */
3557 bc_load_localaddr (DECL_RTL (decl));
3558 bc_emit_instruction (storeP);
3562 /* Emit code to initialize a declaration. */
3565 bc_expand_decl_init (decl)
3568 int org_stack_depth;
3570 /* Statical initializers are handled elsewhere */
3572 if (TREE_STATIC (decl))
3575 /* Memory original stack depth */
3576 org_stack_depth = stack_depth;
3578 /* If the type is variable-size, we first create its space (we ASSUME
3579 it CAN'T be static). We do this regardless of whether there's an
3580 initializer assignment or not. */
3582 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3583 bc_expand_variable_local_init (decl);
3585 /* Expand initializer assignment */
3586 if (DECL_INITIAL (decl) == error_mark_node)
3588 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3590 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3591 || code == POINTER_TYPE)
3593 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3595 else if (DECL_INITIAL (decl))
3596 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3598 /* Restore stack depth */
3599 if (org_stack_depth > stack_depth)
3602 bc_adjust_stack (stack_depth - org_stack_depth);
3606 /* CLEANUP is an expression to be executed at exit from this binding contour;
3607 for example, in C++, it might call the destructor for this variable.
3609 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3610 either before or after calling `expand_decl' but before compiling
3611 any subsequent expressions. This is because CLEANUP may be expanded
3612 more than once, on different branches of execution.
3613 For the same reason, CLEANUP may not contain a CALL_EXPR
3614 except as its topmost node--else `preexpand_calls' would get confused.
3616 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3617 that is not associated with any particular variable. */
3620 expand_decl_cleanup (decl, cleanup)
3623 struct nesting *thisblock = block_stack;
3625 /* Error if we are not in any block. */
3629 /* Record the cleanup if there is one. */
3633 thisblock->data.block.cleanups
3634 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3635 /* If this block has a cleanup, it belongs in stack_block_stack. */
3636 stack_block_stack = thisblock;
3637 (*interim_eh_hook) (NULL_TREE);
3642 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3643 DECL_ELTS is the list of elements that belong to DECL's type.
3644 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3647 expand_anon_union_decl (decl, cleanup, decl_elts)
3648 tree decl, cleanup, decl_elts;
3650 struct nesting *thisblock = block_stack;
3653 expand_decl (decl, cleanup);
3654 x = DECL_RTL (decl);
3658 tree decl_elt = TREE_VALUE (decl_elts);
3659 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3660 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3662 /* Propagate the union's alignment to the elements. */
3663 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3665 /* If the element has BLKmode and the union doesn't, the union is
3666 aligned such that the element doesn't need to have BLKmode, so
3667 change the element's mode to the appropriate one for its size. */
3668 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3669 DECL_MODE (decl_elt) = mode
3670 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3673 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3674 instead create a new MEM rtx with the proper mode. */
3675 if (GET_CODE (x) == MEM)
3677 if (mode == GET_MODE (x))
3678 DECL_RTL (decl_elt) = x;
3681 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3682 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3683 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3686 else if (GET_CODE (x) == REG)
3688 if (mode == GET_MODE (x))
3689 DECL_RTL (decl_elt) = x;
3691 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3696 /* Record the cleanup if there is one. */
3699 thisblock->data.block.cleanups
3700 = temp_tree_cons (decl_elt, cleanup_elt,
3701 thisblock->data.block.cleanups);
3703 decl_elts = TREE_CHAIN (decl_elts);
3707 /* Expand a list of cleanups LIST.
3708 Elements may be expressions or may be nested lists.
3710 If DONT_DO is nonnull, then any list-element
3711 whose TREE_PURPOSE matches DONT_DO is omitted.
3712 This is sometimes used to avoid a cleanup associated with
3713 a value that is being returned out of the scope.
3715 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3716 goto and handle protection regions specially in that case.
3718 If REACHABLE, we emit code, otherwise just inform the exception handling
3719 code about this finalization. */
3722 expand_cleanups (list, dont_do, in_fixup, reachable)
3729 for (tail = list; tail; tail = TREE_CHAIN (tail))
3730 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3732 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3733 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3737 (*interim_eh_hook) (TREE_VALUE (tail));
3741 /* Cleanups may be run multiple times. For example,
3742 when exiting a binding contour, we expand the
3743 cleanups associated with that contour. When a goto
3744 within that binding contour has a target outside that
3745 contour, it will expand all cleanups from its scope to
3746 the target. Though the cleanups are expanded multiple
3747 times, the control paths are non-overlapping so the
3748 cleanups will not be executed twice. */
3749 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3756 /* Move all cleanups from the current block_stack
3757 to the containing block_stack, where they are assumed to
3758 have been created. If anything can cause a temporary to
3759 be created, but not expanded for more than one level of
3760 block_stacks, then this code will have to change. */
3765 struct nesting *block = block_stack;
3766 struct nesting *outer = block->next;
3768 outer->data.block.cleanups
3769 = chainon (block->data.block.cleanups,
3770 outer->data.block.cleanups);
3771 block->data.block.cleanups = 0;
3775 last_cleanup_this_contour ()
3777 if (block_stack == 0)
3780 return block_stack->data.block.cleanups;
3783 /* Return 1 if there are any pending cleanups at this point.
3784 If THIS_CONTOUR is nonzero, check the current contour as well.
3785 Otherwise, look only at the contours that enclose this one. */
3788 any_pending_cleanups (this_contour)
3791 struct nesting *block;
3793 if (block_stack == 0)
3796 if (this_contour && block_stack->data.block.cleanups != NULL)
3798 if (block_stack->data.block.cleanups == 0
3799 && (block_stack->data.block.outer_cleanups == 0
3801 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3806 for (block = block_stack->next; block; block = block->next)
3807 if (block->data.block.cleanups != 0)
3813 /* Enter a case (Pascal) or switch (C) statement.
3814 Push a block onto case_stack and nesting_stack
3815 to accumulate the case-labels that are seen
3816 and to record the labels generated for the statement.
3818 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3819 Otherwise, this construct is transparent for `exit_something'.
3821 EXPR is the index-expression to be dispatched on.
3822 TYPE is its nominal type. We could simply convert EXPR to this type,
3823 but instead we take short cuts. */
3826 expand_start_case (exit_flag, expr, type, printname)
3832 register struct nesting *thiscase = ALLOC_NESTING ();
3834 /* Make an entry on case_stack for the case we are entering. */
3836 thiscase->next = case_stack;
3837 thiscase->all = nesting_stack;
3838 thiscase->depth = ++nesting_depth;
3839 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3840 thiscase->data.case_stmt.case_list = 0;
3841 thiscase->data.case_stmt.index_expr = expr;
3842 thiscase->data.case_stmt.nominal_type = type;
3843 thiscase->data.case_stmt.default_label = 0;
3844 thiscase->data.case_stmt.num_ranges = 0;
3845 thiscase->data.case_stmt.printname = printname;
3846 thiscase->data.case_stmt.seenlabel = 0;
3847 case_stack = thiscase;
3848 nesting_stack = thiscase;
3850 if (output_bytecode)
3852 bc_expand_start_case (thiscase, expr, type, printname);
3856 do_pending_stack_adjust ();
3858 /* Make sure case_stmt.start points to something that won't
3859 need any transformation before expand_end_case. */
3860 if (GET_CODE (get_last_insn ()) != NOTE)
3861 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3863 thiscase->data.case_stmt.start = get_last_insn ();
3867 /* Enter a case statement. It is assumed that the caller has pushed
3868 the current context onto the case stack. */
3871 bc_expand_start_case (thiscase, expr, type, printname)
3872 struct nesting *thiscase;
3877 bc_expand_expr (expr);
3878 bc_expand_conversion (TREE_TYPE (expr), type);
3880 /* For cases, the skip is a place we jump to that's emitted after
3881 the size of the jump table is known. */
3883 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3884 bc_emit_bytecode (jump);
3885 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3887 #ifdef DEBUG_PRINT_CODE
3888 fputc ('\n', stderr);
3893 /* Start a "dummy case statement" within which case labels are invalid
3894 and are not connected to any larger real case statement.
3895 This can be used if you don't want to let a case statement jump
3896 into the middle of certain kinds of constructs. */
3899 expand_start_case_dummy ()
3901 register struct nesting *thiscase = ALLOC_NESTING ();
3903 /* Make an entry on case_stack for the dummy. */
3905 thiscase->next = case_stack;
3906 thiscase->all = nesting_stack;
3907 thiscase->depth = ++nesting_depth;
3908 thiscase->exit_label = 0;
3909 thiscase->data.case_stmt.case_list = 0;
3910 thiscase->data.case_stmt.start = 0;
3911 thiscase->data.case_stmt.nominal_type = 0;
3912 thiscase->data.case_stmt.default_label = 0;
3913 thiscase->data.case_stmt.num_ranges = 0;
3914 case_stack = thiscase;
3915 nesting_stack = thiscase;
3918 /* End a dummy case statement. */
3921 expand_end_case_dummy ()
3923 POPSTACK (case_stack);
3926 /* Return the data type of the index-expression
3927 of the innermost case statement, or null if none. */
3930 case_index_expr_type ()
3933 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3937 /* Accumulate one case or default label inside a case or switch statement.
3938 VALUE is the value of the case (a null pointer, for a default label).
3939 The function CONVERTER, when applied to arguments T and V,
3940 converts the value V to the type T.
3942 If not currently inside a case or switch statement, return 1 and do
3943 nothing. The caller will print a language-specific error message.
3944 If VALUE is a duplicate or overlaps, return 2 and do nothing
3945 except store the (first) duplicate node in *DUPLICATE.
3946 If VALUE is out of range, return 3 and do nothing.
3947 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3948 Return 0 on success.
3950 Extended to handle range statements. */
3953 pushcase (value, converter, label, duplicate)
3954 register tree value;
3955 tree (*converter) PROTO((tree, tree));
3956 register tree label;
3959 register struct case_node **l;
3960 register struct case_node *n;
3964 if (output_bytecode)
3965 return bc_pushcase (value, label);
3967 /* Fail if not inside a real case statement. */
3968 if (! (case_stack && case_stack->data.case_stmt.start))
3971 if (stack_block_stack
3972 && stack_block_stack->depth > case_stack->depth)
3975 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
3976 nominal_type = case_stack->data.case_stmt.nominal_type;
3978 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3979 if (index_type == error_mark_node)
3982 /* Convert VALUE to the type in which the comparisons are nominally done. */
3984 value = (*converter) (nominal_type, value);
3986 /* If this is the first label, warn if any insns have been emitted. */
3987 if (case_stack->data.case_stmt.seenlabel == 0)
3990 for (insn = case_stack->data.case_stmt.start;
3992 insn = NEXT_INSN (insn))
3994 if (GET_CODE (insn) == CODE_LABEL)
3996 if (GET_CODE (insn) != NOTE
3997 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
3999 warning ("unreachable code at beginning of %s",
4000 case_stack->data.case_stmt.printname);
4005 case_stack->data.case_stmt.seenlabel = 1;
4007 /* Fail if this value is out of range for the actual type of the index
4008 (which may be narrower than NOMINAL_TYPE). */
4009 if (value != 0 && ! int_fits_type_p (value, index_type))
4012 /* Fail if this is a duplicate or overlaps another entry. */
4015 if (case_stack->data.case_stmt.default_label != 0)
4017 *duplicate = case_stack->data.case_stmt.default_label;
4020 case_stack->data.case_stmt.default_label = label;
4024 /* Find the elt in the chain before which to insert the new value,
4025 to keep the chain sorted in increasing order.
4026 But report an error if this element is a duplicate. */
4027 for (l = &case_stack->data.case_stmt.case_list;
4028 /* Keep going past elements distinctly less than VALUE. */
4029 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4034 /* Element we will insert before must be distinctly greater;
4035 overlap means error. */
4036 if (! tree_int_cst_lt (value, (*l)->low))
4038 *duplicate = (*l)->code_label;
4043 /* Add this label to the chain, and succeed.
4044 Copy VALUE so it is on temporary rather than momentary
4045 obstack and will thus survive till the end of the case statement. */
4046 n = (struct case_node *) oballoc (sizeof (struct case_node));
4049 n->high = n->low = copy_node (value);
4050 n->code_label = label;
4054 expand_label (label);
4058 /* Like pushcase but this case applies to all values
4059 between VALUE1 and VALUE2 (inclusive).
4060 The return value is the same as that of pushcase
4061 but there is one additional error code:
4062 4 means the specified range was empty. */
4065 pushcase_range (value1, value2, converter, label, duplicate)
4066 register tree value1, value2;
4067 tree (*converter) PROTO((tree, tree));
4068 register tree label;
4071 register struct case_node **l;
4072 register struct case_node *n;
4076 /* Fail if not inside a real case statement. */
4077 if (! (case_stack && case_stack->data.case_stmt.start))
4080 if (stack_block_stack
4081 && stack_block_stack->depth > case_stack->depth)
4084 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4085 nominal_type = case_stack->data.case_stmt.nominal_type;
4087 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4088 if (index_type == error_mark_node)
4091 /* If this is the first label, warn if any insns have been emitted. */
4092 if (case_stack->data.case_stmt.seenlabel == 0)
4095 for (insn = case_stack->data.case_stmt.start;
4097 insn = NEXT_INSN (insn))
4099 if (GET_CODE (insn) == CODE_LABEL)
4101 if (GET_CODE (insn) != NOTE
4102 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4104 warning ("unreachable code at beginning of %s",
4105 case_stack->data.case_stmt.printname);
4110 case_stack->data.case_stmt.seenlabel = 1;
4112 /* Convert VALUEs to type in which the comparisons are nominally done. */
4113 if (value1 == 0) /* Negative infinity. */
4114 value1 = TYPE_MIN_VALUE(index_type);
4115 value1 = (*converter) (nominal_type, value1);
4117 if (value2 == 0) /* Positive infinity. */
4118 value2 = TYPE_MAX_VALUE(index_type);
4119 value2 = (*converter) (nominal_type, value2);
4121 /* Fail if these values are out of range. */
4122 if (! int_fits_type_p (value1, index_type))
4125 if (! int_fits_type_p (value2, index_type))
4128 /* Fail if the range is empty. */
4129 if (tree_int_cst_lt (value2, value1))
4132 /* If the bounds are equal, turn this into the one-value case. */
4133 if (tree_int_cst_equal (value1, value2))
4134 return pushcase (value1, converter, label, duplicate);
4136 /* Find the elt in the chain before which to insert the new value,
4137 to keep the chain sorted in increasing order.
4138 But report an error if this element is a duplicate. */
4139 for (l = &case_stack->data.case_stmt.case_list;
4140 /* Keep going past elements distinctly less than this range. */
4141 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4146 /* Element we will insert before must be distinctly greater;
4147 overlap means error. */
4148 if (! tree_int_cst_lt (value2, (*l)->low))
4150 *duplicate = (*l)->code_label;
4155 /* Add this label to the chain, and succeed.
4156 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4157 obstack and will thus survive till the end of the case statement. */
4159 n = (struct case_node *) oballoc (sizeof (struct case_node));
4162 n->low = copy_node (value1);
4163 n->high = copy_node (value2);
4164 n->code_label = label;
4167 expand_label (label);
4169 case_stack->data.case_stmt.num_ranges++;
4175 /* Accumulate one case or default label; VALUE is the value of the
4176 case, or nil for a default label. If not currently inside a case,
4177 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4178 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4179 Return 0 on success. This function is a leftover from the earlier
4180 bytecode compiler, which was based on gcc 1.37. It should be
4181 merged into pushcase. */
4184 bc_pushcase (value, label)
4188 struct nesting *thiscase = case_stack;
4189 struct case_node *case_label, *new_label;
4194 /* Fail if duplicate, overlap, or out of type range. */
4197 value = convert (thiscase->data.case_stmt.nominal_type, value);
4198 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4201 for (case_label = thiscase->data.case_stmt.case_list;
4202 case_label->left; case_label = case_label->left)
4203 if (! tree_int_cst_lt (case_label->left->high, value))
4206 if (case_label != thiscase->data.case_stmt.case_list
4207 && ! tree_int_cst_lt (case_label->high, value)
4208 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4211 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4212 new_label->low = new_label->high = copy_node (value);
4213 new_label->code_label = label;
4214 new_label->left = case_label->left;
4216 case_label->left = new_label;
4217 thiscase->data.case_stmt.num_ranges++;
4221 if (thiscase->data.case_stmt.default_label)
4223 thiscase->data.case_stmt.default_label = label;
4226 expand_label (label);
4230 /* Returns the number of possible values of TYPE.
4231 Returns -1 if the number is unknown or variable.
4232 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4233 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4234 do not increase monotonically (there may be duplicates);
4235 to 1 if the values increase monotonically, but not always by 1;
4236 otherwise sets it to 0. */
4239 all_cases_count (type, spareness)
4243 HOST_WIDE_INT count, count_high = 0;
4246 switch (TREE_CODE (type))
4253 count = 1 << BITS_PER_UNIT;
4257 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4258 || TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST)
4263 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4264 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4265 but with overflow checking. */
4266 tree mint = TYPE_MIN_VALUE (type);
4267 tree maxt = TYPE_MAX_VALUE (type);
4268 HOST_WIDE_INT lo, hi;
4269 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4271 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4273 add_double (lo, hi, 1, 0, &lo, &hi);
4274 if (hi != 0 || lo < 0)
4281 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4283 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4284 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4285 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4286 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4290 if (*spareness == 1)
4292 tree prev = TREE_VALUE (TYPE_VALUES (type));
4293 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4295 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4300 prev = TREE_VALUE (t);
4309 #define BITARRAY_TEST(ARRAY, INDEX) \
4310 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4311 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4312 #define BITARRAY_SET(ARRAY, INDEX) \
4313 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4314 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4316 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4317 with the case values we have seen, assuming the case expression
4319 SPARSENESS is as determined by all_cases_count.
4321 The time needed is propotional to COUNT, unless
4322 SPARSENESS is 2, in which case quadratic time is needed. */
4325 mark_seen_cases (type, cases_seen, count, sparseness)
4327 unsigned char *cases_seen;
4333 tree next_node_to_try = NULL_TREE;
4334 long next_node_offset = 0;
4336 register struct case_node *n;
4337 tree val = make_node (INTEGER_CST);
4338 TREE_TYPE (val) = type;
4339 for (n = case_stack->data.case_stmt.case_list; n;
4342 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4343 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4344 while ( ! tree_int_cst_lt (n->high, val))
4346 /* Calculate (into xlo) the "offset" of the integer (val).
4347 The element with lowest value has offset 0, the next smallest
4348 element has offset 1, etc. */
4350 HOST_WIDE_INT xlo, xhi;
4352 if (sparseness == 2)
4354 /* This less efficient loop is only needed to handle
4355 duplicate case values (multiple enum constants
4356 with the same value). */
4357 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4358 t = TREE_CHAIN (t), xlo++)
4360 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4361 BITARRAY_SET (cases_seen, xlo);
4366 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4368 /* The TYPE_VALUES will be in increasing order, so
4369 starting searching where we last ended. */
4370 t = next_node_to_try;
4371 xlo = next_node_offset;
4377 t = TYPE_VALUES (type);
4380 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4382 next_node_to_try = TREE_CHAIN (t);
4383 next_node_offset = xlo + 1;
4388 if (t == next_node_to_try)
4394 t = TYPE_MIN_VALUE (type);
4396 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4400 add_double (xlo, xhi,
4401 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4405 if (xhi == 0 && xlo >= 0 && xlo < count)
4406 BITARRAY_SET (cases_seen, xlo);
4408 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4410 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4415 /* Called when the index of a switch statement is an enumerated type
4416 and there is no default label.
4418 Checks that all enumeration literals are covered by the case
4419 expressions of a switch. Also, warn if there are any extra
4420 switch cases that are *not* elements of the enumerated type.
4422 If all enumeration literals were covered by the case expressions,
4423 turn one of the expressions into the default expression since it should
4424 not be possible to fall through such a switch. */
4427 check_for_full_enumeration_handling (type)
4430 register struct case_node *n;
4431 register struct case_node **l;
4432 register tree chain;
4435 /* True iff the selector type is a numbered set mode. */
4438 /* The number of possible selector values. */
4441 /* For each possible selector value. a one iff it has been matched
4442 by a case value alternative. */
4443 unsigned char *cases_seen;
4445 /* The allocated size of cases_seen, in chars. */
4449 if (output_bytecode)
4451 bc_check_for_full_enumeration_handling (type);
4458 size = all_cases_count (type, &sparseness);
4459 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4461 if (size > 0 && size < 600000
4462 /* We deliberately use malloc here - not xmalloc. */
4463 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4466 tree v = TYPE_VALUES (type);
4467 bzero (cases_seen, bytes_needed);
4469 /* The time complexity of this code is normally O(N), where
4470 N being the number of members in the enumerated type.
4471 However, if type is a ENUMERAL_TYPE whose values do not
4472 increase monotonically, quadratic time may be needed. */
4474 mark_seen_cases (type, cases_seen, size, sparseness);
4476 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4478 if (BITARRAY_TEST(cases_seen, i) == 0)
4479 warning ("enumeration value `%s' not handled in switch",
4480 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4486 /* Now we go the other way around; we warn if there are case
4487 expressions that don't correspond to enumerators. This can
4488 occur since C and C++ don't enforce type-checking of
4489 assignments to enumeration variables. */
4492 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4494 for (chain = TYPE_VALUES (type);
4495 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4496 chain = TREE_CHAIN (chain))
4501 if (TYPE_NAME (type) == 0)
4502 warning ("case value `%d' not in enumerated type",
4503 TREE_INT_CST_LOW (n->low));
4505 warning ("case value `%d' not in enumerated type `%s'",
4506 TREE_INT_CST_LOW (n->low),
4507 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4510 : DECL_NAME (TYPE_NAME (type))));
4512 if (!tree_int_cst_equal (n->low, n->high))
4514 for (chain = TYPE_VALUES (type);
4515 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4516 chain = TREE_CHAIN (chain))
4521 if (TYPE_NAME (type) == 0)
4522 warning ("case value `%d' not in enumerated type",
4523 TREE_INT_CST_LOW (n->high));
4525 warning ("case value `%d' not in enumerated type `%s'",
4526 TREE_INT_CST_LOW (n->high),
4527 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4530 : DECL_NAME (TYPE_NAME (type))));
4536 /* ??? This optimization is disabled because it causes valid programs to
4537 fail. ANSI C does not guarantee that an expression with enum type
4538 will have a value that is the same as one of the enumation literals. */
4540 /* If all values were found as case labels, make one of them the default
4541 label. Thus, this switch will never fall through. We arbitrarily pick
4542 the last one to make the default since this is likely the most
4543 efficient choice. */
4547 for (l = &case_stack->data.case_stmt.case_list;
4552 case_stack->data.case_stmt.default_label = (*l)->code_label;
4559 /* Check that all enumeration literals are covered by the case
4560 expressions of a switch. Also warn if there are any cases
4561 that are not elements of the enumerated type. */
4564 bc_check_for_full_enumeration_handling (type)
4567 struct nesting *thiscase = case_stack;
4568 struct case_node *c;
4571 /* Check for enums not handled. */
4572 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4574 for (c = thiscase->data.case_stmt.case_list->left;
4575 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4578 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4579 warning ("enumerated value `%s' not handled in switch",
4580 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4583 /* Check for cases not in the enumeration. */
4584 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4586 for (e = TYPE_VALUES (type);
4587 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4591 warning ("case value `%d' not in enumerated type `%s'",
4592 TREE_INT_CST_LOW (c->low),
4593 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4595 : DECL_NAME (TYPE_NAME (type))));
4599 /* Terminate a case (Pascal) or switch (C) statement
4600 in which ORIG_INDEX is the expression to be tested.
4601 Generate the code to test it and jump to the right place. */
4604 expand_end_case (orig_index)
4607 tree minval, maxval, range, orig_minval;
4608 rtx default_label = 0;
4609 register struct case_node *n;
4617 register struct nesting *thiscase = case_stack;
4618 tree index_expr, index_type;
4621 if (output_bytecode)
4623 bc_expand_end_case (orig_index);
4627 table_label = gen_label_rtx ();
4628 index_expr = thiscase->data.case_stmt.index_expr;
4629 index_type = TREE_TYPE (index_expr);
4630 unsignedp = TREE_UNSIGNED (index_type);
4632 do_pending_stack_adjust ();
4634 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4635 if (index_type != error_mark_node)
4637 /* If switch expression was an enumerated type, check that all
4638 enumeration literals are covered by the cases.
4639 No sense trying this if there's a default case, however. */
4641 if (!thiscase->data.case_stmt.default_label
4642 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4643 && TREE_CODE (index_expr) != INTEGER_CST)
4644 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4646 /* If this is the first label, warn if any insns have been emitted. */
4647 if (thiscase->data.case_stmt.seenlabel == 0)
4650 for (insn = get_last_insn ();
4651 insn != case_stack->data.case_stmt.start;
4652 insn = PREV_INSN (insn))
4653 if (GET_CODE (insn) != NOTE
4654 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4656 warning ("unreachable code at beginning of %s",
4657 case_stack->data.case_stmt.printname);
4662 /* If we don't have a default-label, create one here,
4663 after the body of the switch. */
4664 if (thiscase->data.case_stmt.default_label == 0)
4666 thiscase->data.case_stmt.default_label
4667 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4668 expand_label (thiscase->data.case_stmt.default_label);
4670 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4672 before_case = get_last_insn ();
4674 /* Simplify the case-list before we count it. */
4675 group_case_nodes (thiscase->data.case_stmt.case_list);
4677 /* Get upper and lower bounds of case values.
4678 Also convert all the case values to the index expr's data type. */
4681 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4683 /* Check low and high label values are integers. */
4684 if (TREE_CODE (n->low) != INTEGER_CST)
4686 if (TREE_CODE (n->high) != INTEGER_CST)
4689 n->low = convert (index_type, n->low);
4690 n->high = convert (index_type, n->high);
4692 /* Count the elements and track the largest and smallest
4693 of them (treating them as signed even if they are not). */
4701 if (INT_CST_LT (n->low, minval))
4703 if (INT_CST_LT (maxval, n->high))
4706 /* A range counts double, since it requires two compares. */
4707 if (! tree_int_cst_equal (n->low, n->high))
4711 orig_minval = minval;
4713 /* Compute span of values. */
4715 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4719 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4721 emit_jump (default_label);
4724 /* If range of values is much bigger than number of values,
4725 make a sequence of conditional branches instead of a dispatch.
4726 If the switch-index is a constant, do it this way
4727 because we can optimize it. */
4729 #ifndef CASE_VALUES_THRESHOLD
4731 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4733 /* If machine does not have a case insn that compares the
4734 bounds, this means extra overhead for dispatch tables
4735 which raises the threshold for using them. */
4736 #define CASE_VALUES_THRESHOLD 5
4737 #endif /* HAVE_casesi */
4738 #endif /* CASE_VALUES_THRESHOLD */
4740 else if (TREE_INT_CST_HIGH (range) != 0
4741 || count < CASE_VALUES_THRESHOLD
4742 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4744 || TREE_CODE (index_expr) == INTEGER_CST
4745 /* These will reduce to a constant. */
4746 || (TREE_CODE (index_expr) == CALL_EXPR
4747 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4748 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4749 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4750 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4751 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4753 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4755 /* If the index is a short or char that we do not have
4756 an insn to handle comparisons directly, convert it to
4757 a full integer now, rather than letting each comparison
4758 generate the conversion. */
4760 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4761 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4762 == CODE_FOR_nothing))
4764 enum machine_mode wider_mode;
4765 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4766 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4767 if (cmp_optab->handlers[(int) wider_mode].insn_code
4768 != CODE_FOR_nothing)
4770 index = convert_to_mode (wider_mode, index, unsignedp);
4776 do_pending_stack_adjust ();
4778 index = protect_from_queue (index, 0);
4779 if (GET_CODE (index) == MEM)
4780 index = copy_to_reg (index);
4781 if (GET_CODE (index) == CONST_INT
4782 || TREE_CODE (index_expr) == INTEGER_CST)
4784 /* Make a tree node with the proper constant value
4785 if we don't already have one. */
4786 if (TREE_CODE (index_expr) != INTEGER_CST)
4789 = build_int_2 (INTVAL (index),
4790 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4791 index_expr = convert (index_type, index_expr);
4794 /* For constant index expressions we need only
4795 issue a unconditional branch to the appropriate
4796 target code. The job of removing any unreachable
4797 code is left to the optimisation phase if the
4798 "-O" option is specified. */
4799 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4800 if (! tree_int_cst_lt (index_expr, n->low)
4801 && ! tree_int_cst_lt (n->high, index_expr))
4805 emit_jump (label_rtx (n->code_label));
4807 emit_jump (default_label);
4811 /* If the index expression is not constant we generate
4812 a binary decision tree to select the appropriate
4813 target code. This is done as follows:
4815 The list of cases is rearranged into a binary tree,
4816 nearly optimal assuming equal probability for each case.
4818 The tree is transformed into RTL, eliminating
4819 redundant test conditions at the same time.
4821 If program flow could reach the end of the
4822 decision tree an unconditional jump to the
4823 default code is emitted. */
4826 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4827 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4828 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4830 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4831 default_label, index_type);
4832 emit_jump_if_reachable (default_label);
4841 enum machine_mode index_mode = SImode;
4842 int index_bits = GET_MODE_BITSIZE (index_mode);
4844 enum machine_mode op_mode;
4846 /* Convert the index to SImode. */
4847 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4848 > GET_MODE_BITSIZE (index_mode))
4850 enum machine_mode omode = TYPE_MODE (index_type);
4851 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4853 /* We must handle the endpoints in the original mode. */
4854 index_expr = build (MINUS_EXPR, index_type,
4855 index_expr, minval);
4856 minval = integer_zero_node;
4857 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4858 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4859 emit_jump_insn (gen_bltu (default_label));
4860 /* Now we can safely truncate. */
4861 index = convert_to_mode (index_mode, index, 0);
4865 if (TYPE_MODE (index_type) != index_mode)
4867 index_expr = convert (type_for_size (index_bits, 0),
4869 index_type = TREE_TYPE (index_expr);
4872 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4875 index = protect_from_queue (index, 0);
4876 do_pending_stack_adjust ();
4878 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4879 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4881 index = copy_to_mode_reg (op_mode, index);
4883 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4885 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4886 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4888 op1 = copy_to_mode_reg (op_mode, op1);
4890 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4892 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4893 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4895 op2 = copy_to_mode_reg (op_mode, op2);
4897 emit_jump_insn (gen_casesi (index, op1, op2,
4898 table_label, default_label));
4902 #ifdef HAVE_tablejump
4903 if (! win && HAVE_tablejump)
4905 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4906 fold (build (MINUS_EXPR, index_type,
4907 index_expr, minval)));
4908 index_type = TREE_TYPE (index_expr);
4909 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4911 index = protect_from_queue (index, 0);
4912 do_pending_stack_adjust ();
4914 do_tablejump (index, TYPE_MODE (index_type),
4915 expand_expr (range, NULL_RTX, VOIDmode, 0),
4916 table_label, default_label);
4923 /* Get table of labels to jump to, in order of case index. */
4925 ncases = TREE_INT_CST_LOW (range) + 1;
4926 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4927 bzero ((char *) labelvec, ncases * sizeof (rtx));
4929 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4931 register HOST_WIDE_INT i
4932 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4937 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4938 if (i + TREE_INT_CST_LOW (orig_minval)
4939 == TREE_INT_CST_LOW (n->high))
4945 /* Fill in the gaps with the default. */
4946 for (i = 0; i < ncases; i++)
4947 if (labelvec[i] == 0)
4948 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4950 /* Output the table */
4951 emit_label (table_label);
4953 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
4954 were an expression, instead of an #ifdef/#ifndef. */
4956 #ifdef CASE_VECTOR_PC_RELATIVE
4960 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
4961 gen_rtx (LABEL_REF, Pmode, table_label),
4962 gen_rtvec_v (ncases, labelvec)));
4964 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
4965 gen_rtvec_v (ncases, labelvec)));
4967 /* If the case insn drops through the table,
4968 after the table we must jump to the default-label.
4969 Otherwise record no drop-through after the table. */
4970 #ifdef CASE_DROPS_THROUGH
4971 emit_jump (default_label);
4977 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
4978 reorder_insns (before_case, get_last_insn (),
4979 thiscase->data.case_stmt.start);
4982 if (thiscase->exit_label)
4983 emit_label (thiscase->exit_label);
4985 POPSTACK (case_stack);
4991 /* Terminate a case statement. EXPR is the original index
4995 bc_expand_end_case (expr)
4998 struct nesting *thiscase = case_stack;
4999 enum bytecode_opcode opcode;
5000 struct bc_label *jump_label;
5001 struct case_node *c;
5003 bc_emit_bytecode (jump);
5004 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5006 #ifdef DEBUG_PRINT_CODE
5007 fputc ('\n', stderr);
5010 /* Now that the size of the jump table is known, emit the actual
5011 indexed jump instruction. */
5012 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5014 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5015 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5016 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5018 bc_emit_bytecode (opcode);
5020 /* Now emit the case instructions literal arguments, in order.
5021 In addition to the value on the stack, it uses:
5022 1. The address of the jump table.
5023 2. The size of the jump table.
5024 3. The default label. */
5026 jump_label = bc_get_bytecode_label ();
5027 bc_emit_bytecode_labelref (jump_label);
5028 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5029 sizeof thiscase->data.case_stmt.num_ranges);
5031 if (thiscase->data.case_stmt.default_label)
5032 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5034 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5036 /* Output the jump table. */
5038 bc_align_bytecode (3 /* PTR_ALIGN */);
5039 bc_emit_bytecode_labeldef (jump_label);
5041 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5042 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5044 opcode = TREE_INT_CST_LOW (c->low);
5045 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5047 opcode = TREE_INT_CST_LOW (c->high);
5048 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5050 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5053 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5054 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5056 bc_emit_bytecode_DI_const (c->low);
5057 bc_emit_bytecode_DI_const (c->high);
5059 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5066 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5068 /* Possibly issue enumeration warnings. */
5070 if (!thiscase->data.case_stmt.default_label
5071 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5072 && TREE_CODE (expr) != INTEGER_CST
5074 check_for_full_enumeration_handling (TREE_TYPE (expr));
5077 #ifdef DEBUG_PRINT_CODE
5078 fputc ('\n', stderr);
5081 POPSTACK (case_stack);
5085 /* Return unique bytecode ID. */
5090 static int bc_uid = 0;
5095 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5098 do_jump_if_equal (op1, op2, label, unsignedp)
5099 rtx op1, op2, label;
5102 if (GET_CODE (op1) == CONST_INT
5103 && GET_CODE (op2) == CONST_INT)
5105 if (INTVAL (op1) == INTVAL (op2))
5110 enum machine_mode mode = GET_MODE (op1);
5111 if (mode == VOIDmode)
5112 mode = GET_MODE (op2);
5113 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5114 emit_jump_insn (gen_beq (label));
5118 /* Not all case values are encountered equally. This function
5119 uses a heuristic to weight case labels, in cases where that
5120 looks like a reasonable thing to do.
5122 Right now, all we try to guess is text, and we establish the
5125 chars above space: 16
5134 If we find any cases in the switch that are not either -1 or in the range
5135 of valid ASCII characters, or are control characters other than those
5136 commonly used with "\", don't treat this switch scanning text.
5138 Return 1 if these nodes are suitable for cost estimation, otherwise
5142 estimate_case_costs (node)
5145 tree min_ascii = build_int_2 (-1, -1);
5146 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5150 /* If we haven't already made the cost table, make it now. Note that the
5151 lower bound of the table is -1, not zero. */
5153 if (cost_table == NULL)
5155 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5156 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5158 for (i = 0; i < 128; i++)
5162 else if (ispunct (i))
5164 else if (iscntrl (i))
5168 cost_table[' '] = 8;
5169 cost_table['\t'] = 4;
5170 cost_table['\0'] = 4;
5171 cost_table['\n'] = 2;
5172 cost_table['\f'] = 1;
5173 cost_table['\v'] = 1;
5174 cost_table['\b'] = 1;
5177 /* See if all the case expressions look like text. It is text if the
5178 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5179 as signed arithmetic since we don't want to ever access cost_table with a
5180 value less than -1. Also check that none of the constants in a range
5181 are strange control characters. */
5183 for (n = node; n; n = n->right)
5185 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5188 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5189 if (cost_table[i] < 0)
5193 /* All interesting values are within the range of interesting
5194 ASCII characters. */
5198 /* Scan an ordered list of case nodes
5199 combining those with consecutive values or ranges.
5201 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5204 group_case_nodes (head)
5207 case_node_ptr node = head;
5211 rtx lb = next_real_insn (label_rtx (node->code_label));
5212 case_node_ptr np = node;
5214 /* Try to group the successors of NODE with NODE. */
5215 while (((np = np->right) != 0)
5216 /* Do they jump to the same place? */
5217 && next_real_insn (label_rtx (np->code_label)) == lb
5218 /* Are their ranges consecutive? */
5219 && tree_int_cst_equal (np->low,
5220 fold (build (PLUS_EXPR,
5221 TREE_TYPE (node->high),
5224 /* An overflow is not consecutive. */
5225 && tree_int_cst_lt (node->high,
5226 fold (build (PLUS_EXPR,
5227 TREE_TYPE (node->high),
5229 integer_one_node))))
5231 node->high = np->high;
5233 /* NP is the first node after NODE which can't be grouped with it.
5234 Delete the nodes in between, and move on to that node. */
5240 /* Take an ordered list of case nodes
5241 and transform them into a near optimal binary tree,
5242 on the assumption that any target code selection value is as
5243 likely as any other.
5245 The transformation is performed by splitting the ordered
5246 list into two equal sections plus a pivot. The parts are
5247 then attached to the pivot as left and right branches. Each
5248 branch is is then transformed recursively. */
5251 balance_case_nodes (head, parent)
5252 case_node_ptr *head;
5253 case_node_ptr parent;
5255 register case_node_ptr np;
5263 register case_node_ptr *npp;
5266 /* Count the number of entries on branch. Also count the ranges. */
5270 if (!tree_int_cst_equal (np->low, np->high))
5274 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5278 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5286 /* Split this list if it is long enough for that to help. */
5291 /* Find the place in the list that bisects the list's total cost,
5292 Here I gets half the total cost. */
5297 /* Skip nodes while their cost does not reach that amount. */
5298 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5299 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5300 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5303 npp = &(*npp)->right;
5308 /* Leave this branch lopsided, but optimize left-hand
5309 side and fill in `parent' fields for right-hand side. */
5311 np->parent = parent;
5312 balance_case_nodes (&np->left, np);
5313 for (; np->right; np = np->right)
5314 np->right->parent = np;
5318 /* If there are just three nodes, split at the middle one. */
5320 npp = &(*npp)->right;
5323 /* Find the place in the list that bisects the list's total cost,
5324 where ranges count as 2.
5325 Here I gets half the total cost. */
5326 i = (i + ranges + 1) / 2;
5329 /* Skip nodes while their cost does not reach that amount. */
5330 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5335 npp = &(*npp)->right;
5340 np->parent = parent;
5343 /* Optimize each of the two split parts. */
5344 balance_case_nodes (&np->left, np);
5345 balance_case_nodes (&np->right, np);
5349 /* Else leave this branch as one level,
5350 but fill in `parent' fields. */
5352 np->parent = parent;
5353 for (; np->right; np = np->right)
5354 np->right->parent = np;
5359 /* Search the parent sections of the case node tree
5360 to see if a test for the lower bound of NODE would be redundant.
5361 INDEX_TYPE is the type of the index expression.
5363 The instructions to generate the case decision tree are
5364 output in the same order as nodes are processed so it is
5365 known that if a parent node checks the range of the current
5366 node minus one that the current node is bounded at its lower
5367 span. Thus the test would be redundant. */
5370 node_has_low_bound (node, index_type)
5375 case_node_ptr pnode;
5377 /* If the lower bound of this node is the lowest value in the index type,
5378 we need not test it. */
5380 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5383 /* If this node has a left branch, the value at the left must be less
5384 than that at this node, so it cannot be bounded at the bottom and
5385 we need not bother testing any further. */
5390 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5391 node->low, integer_one_node));
5393 /* If the subtraction above overflowed, we can't verify anything.
5394 Otherwise, look for a parent that tests our value - 1. */
5396 if (! tree_int_cst_lt (low_minus_one, node->low))
5399 for (pnode = node->parent; pnode; pnode = pnode->parent)
5400 if (tree_int_cst_equal (low_minus_one, pnode->high))
5406 /* Search the parent sections of the case node tree
5407 to see if a test for the upper bound of NODE would be redundant.
5408 INDEX_TYPE is the type of the index expression.
5410 The instructions to generate the case decision tree are
5411 output in the same order as nodes are processed so it is
5412 known that if a parent node checks the range of the current
5413 node plus one that the current node is bounded at its upper
5414 span. Thus the test would be redundant. */
5417 node_has_high_bound (node, index_type)
5422 case_node_ptr pnode;
5424 /* If the upper bound of this node is the highest value in the type
5425 of the index expression, we need not test against it. */
5427 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5430 /* If this node has a right branch, the value at the right must be greater
5431 than that at this node, so it cannot be bounded at the top and
5432 we need not bother testing any further. */
5437 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5438 node->high, integer_one_node));
5440 /* If the addition above overflowed, we can't verify anything.
5441 Otherwise, look for a parent that tests our value + 1. */
5443 if (! tree_int_cst_lt (node->high, high_plus_one))
5446 for (pnode = node->parent; pnode; pnode = pnode->parent)
5447 if (tree_int_cst_equal (high_plus_one, pnode->low))
5453 /* Search the parent sections of the
5454 case node tree to see if both tests for the upper and lower
5455 bounds of NODE would be redundant. */
5458 node_is_bounded (node, index_type)
5462 return (node_has_low_bound (node, index_type)
5463 && node_has_high_bound (node, index_type));
5466 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5469 emit_jump_if_reachable (label)
5472 if (GET_CODE (get_last_insn ()) != BARRIER)
5476 /* Emit step-by-step code to select a case for the value of INDEX.
5477 The thus generated decision tree follows the form of the
5478 case-node binary tree NODE, whose nodes represent test conditions.
5479 INDEX_TYPE is the type of the index of the switch.
5481 Care is taken to prune redundant tests from the decision tree
5482 by detecting any boundary conditions already checked by
5483 emitted rtx. (See node_has_high_bound, node_has_low_bound
5484 and node_is_bounded, above.)
5486 Where the test conditions can be shown to be redundant we emit
5487 an unconditional jump to the target code. As a further
5488 optimization, the subordinates of a tree node are examined to
5489 check for bounded nodes. In this case conditional and/or
5490 unconditional jumps as a result of the boundary check for the
5491 current node are arranged to target the subordinates associated
5492 code for out of bound conditions on the current node node.
5494 We can assume that when control reaches the code generated here,
5495 the index value has already been compared with the parents
5496 of this node, and determined to be on the same side of each parent
5497 as this node is. Thus, if this node tests for the value 51,
5498 and a parent tested for 52, we don't need to consider
5499 the possibility of a value greater than 51. If another parent
5500 tests for the value 50, then this node need not test anything. */
5503 emit_case_nodes (index, node, default_label, index_type)
5509 /* If INDEX has an unsigned type, we must make unsigned branches. */
5510 int unsignedp = TREE_UNSIGNED (index_type);
5511 typedef rtx rtx_function ();
5512 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5513 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5514 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5515 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5516 enum machine_mode mode = GET_MODE (index);
5518 /* See if our parents have already tested everything for us.
5519 If they have, emit an unconditional jump for this node. */
5520 if (node_is_bounded (node, index_type))
5521 emit_jump (label_rtx (node->code_label));
5523 else if (tree_int_cst_equal (node->low, node->high))
5525 /* Node is single valued. First see if the index expression matches
5526 this node and then check our children, if any. */
5528 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5529 label_rtx (node->code_label), unsignedp);
5531 if (node->right != 0 && node->left != 0)
5533 /* This node has children on both sides.
5534 Dispatch to one side or the other
5535 by comparing the index value with this node's value.
5536 If one subtree is bounded, check that one first,
5537 so we can avoid real branches in the tree. */
5539 if (node_is_bounded (node->right, index_type))
5541 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5543 GT, NULL_RTX, mode, unsignedp, 0);
5545 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5546 emit_case_nodes (index, node->left, default_label, index_type);
5549 else if (node_is_bounded (node->left, index_type))
5551 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5553 LT, NULL_RTX, mode, unsignedp, 0);
5554 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5555 emit_case_nodes (index, node->right, default_label, index_type);
5560 /* Neither node is bounded. First distinguish the two sides;
5561 then emit the code for one side at a time. */
5564 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5566 /* See if the value is on the right. */
5567 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5569 GT, NULL_RTX, mode, unsignedp, 0);
5570 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5572 /* Value must be on the left.
5573 Handle the left-hand subtree. */
5574 emit_case_nodes (index, node->left, default_label, index_type);
5575 /* If left-hand subtree does nothing,
5577 emit_jump_if_reachable (default_label);
5579 /* Code branches here for the right-hand subtree. */
5580 expand_label (test_label);
5581 emit_case_nodes (index, node->right, default_label, index_type);
5585 else if (node->right != 0 && node->left == 0)
5587 /* Here we have a right child but no left so we issue conditional
5588 branch to default and process the right child.
5590 Omit the conditional branch to default if we it avoid only one
5591 right child; it costs too much space to save so little time. */
5593 if (node->right->right || node->right->left
5594 || !tree_int_cst_equal (node->right->low, node->right->high))
5596 if (!node_has_low_bound (node, index_type))
5598 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5600 LT, NULL_RTX, mode, unsignedp, 0);
5601 emit_jump_insn ((*gen_blt_pat) (default_label));
5604 emit_case_nodes (index, node->right, default_label, index_type);
5607 /* We cannot process node->right normally
5608 since we haven't ruled out the numbers less than
5609 this node's value. So handle node->right explicitly. */
5610 do_jump_if_equal (index,
5611 expand_expr (node->right->low, NULL_RTX,
5613 label_rtx (node->right->code_label), unsignedp);
5616 else if (node->right == 0 && node->left != 0)
5618 /* Just one subtree, on the left. */
5620 #if 0 /* The following code and comment were formerly part
5621 of the condition here, but they didn't work
5622 and I don't understand what the idea was. -- rms. */
5623 /* If our "most probable entry" is less probable
5624 than the default label, emit a jump to
5625 the default label using condition codes
5626 already lying around. With no right branch,
5627 a branch-greater-than will get us to the default
5630 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5633 if (node->left->left || node->left->right
5634 || !tree_int_cst_equal (node->left->low, node->left->high))
5636 if (!node_has_high_bound (node, index_type))
5638 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5640 GT, NULL_RTX, mode, unsignedp, 0);
5641 emit_jump_insn ((*gen_bgt_pat) (default_label));
5644 emit_case_nodes (index, node->left, default_label, index_type);
5647 /* We cannot process node->left normally
5648 since we haven't ruled out the numbers less than
5649 this node's value. So handle node->left explicitly. */
5650 do_jump_if_equal (index,
5651 expand_expr (node->left->low, NULL_RTX,
5653 label_rtx (node->left->code_label), unsignedp);
5658 /* Node is a range. These cases are very similar to those for a single
5659 value, except that we do not start by testing whether this node
5660 is the one to branch to. */
5662 if (node->right != 0 && node->left != 0)
5664 /* Node has subtrees on both sides.
5665 If the right-hand subtree is bounded,
5666 test for it first, since we can go straight there.
5667 Otherwise, we need to make a branch in the control structure,
5668 then handle the two subtrees. */
5669 tree test_label = 0;
5671 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5673 GT, NULL_RTX, mode, unsignedp, 0);
5675 if (node_is_bounded (node->right, index_type))
5676 /* Right hand node is fully bounded so we can eliminate any
5677 testing and branch directly to the target code. */
5678 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5681 /* Right hand node requires testing.
5682 Branch to a label where we will handle it later. */
5684 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5685 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5688 /* Value belongs to this node or to the left-hand subtree. */
5690 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5691 GE, NULL_RTX, mode, unsignedp, 0);
5692 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5694 /* Handle the left-hand subtree. */
5695 emit_case_nodes (index, node->left, default_label, index_type);
5697 /* If right node had to be handled later, do that now. */
5701 /* If the left-hand subtree fell through,
5702 don't let it fall into the right-hand subtree. */
5703 emit_jump_if_reachable (default_label);
5705 expand_label (test_label);
5706 emit_case_nodes (index, node->right, default_label, index_type);
5710 else if (node->right != 0 && node->left == 0)
5712 /* Deal with values to the left of this node,
5713 if they are possible. */
5714 if (!node_has_low_bound (node, index_type))
5716 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5718 LT, NULL_RTX, mode, unsignedp, 0);
5719 emit_jump_insn ((*gen_blt_pat) (default_label));
5722 /* Value belongs to this node or to the right-hand subtree. */
5724 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5726 LE, NULL_RTX, mode, unsignedp, 0);
5727 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5729 emit_case_nodes (index, node->right, default_label, index_type);
5732 else if (node->right == 0 && node->left != 0)
5734 /* Deal with values to the right of this node,
5735 if they are possible. */
5736 if (!node_has_high_bound (node, index_type))
5738 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5740 GT, NULL_RTX, mode, unsignedp, 0);
5741 emit_jump_insn ((*gen_bgt_pat) (default_label));
5744 /* Value belongs to this node or to the left-hand subtree. */
5746 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5747 GE, NULL_RTX, mode, unsignedp, 0);
5748 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5750 emit_case_nodes (index, node->left, default_label, index_type);
5755 /* Node has no children so we check low and high bounds to remove
5756 redundant tests. Only one of the bounds can exist,
5757 since otherwise this node is bounded--a case tested already. */
5759 if (!node_has_high_bound (node, index_type))
5761 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5763 GT, NULL_RTX, mode, unsignedp, 0);
5764 emit_jump_insn ((*gen_bgt_pat) (default_label));
5767 if (!node_has_low_bound (node, index_type))
5769 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5771 LT, NULL_RTX, mode, unsignedp, 0);
5772 emit_jump_insn ((*gen_blt_pat) (default_label));
5775 emit_jump (label_rtx (node->code_label));
5780 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5781 so that the debugging info will be correct for the unrolled loop. */
5783 /* Indexed by block number, contains a pointer to the N'th block node. */
5785 static tree *block_vector;
5788 find_loop_tree_blocks ()
5790 tree block = DECL_INITIAL (current_function_decl);
5792 /* There first block is for the function body, and does not have
5793 corresponding block notes. Don't include it in the block vector. */
5794 block = BLOCK_SUBBLOCKS (block);
5796 block_vector = identify_blocks (block, get_insns ());
5800 unroll_block_trees ()
5802 tree block = DECL_INITIAL (current_function_decl);
5804 reorder_blocks (block_vector, block, get_insns ());