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,
3094 emit_label (afterward);
3097 /* Don't allow jumping into a block that has cleanups or a stack level. */
3099 || thisblock->data.block.stack_level != 0
3100 || thisblock->data.block.cleanups != 0)
3102 struct label_chain *chain;
3104 /* Any labels in this block are no longer valid to go to.
3105 Mark them to cause an error message. */
3106 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3108 DECL_TOO_LATE (chain->label) = 1;
3109 /* If any goto without a fixup came to this label,
3110 that must be an error, because gotos without fixups
3111 come from outside all saved stack-levels and all cleanups. */
3112 if (TREE_ADDRESSABLE (chain->label))
3113 error_with_decl (chain->label,
3114 "label `%s' used before containing binding contour");
3118 /* Restore stack level in effect before the block
3119 (only if variable-size objects allocated). */
3120 /* Perform any cleanups associated with the block. */
3122 if (thisblock->data.block.stack_level != 0
3123 || thisblock->data.block.cleanups != 0)
3125 /* Only clean up here if this point can actually be reached. */
3126 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3128 /* Don't let cleanups affect ({...}) constructs. */
3129 int old_expr_stmts_for_value = expr_stmts_for_value;
3130 rtx old_last_expr_value = last_expr_value;
3131 tree old_last_expr_type = last_expr_type;
3132 expr_stmts_for_value = 0;
3134 /* Do the cleanups. */
3135 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3137 do_pending_stack_adjust ();
3139 expr_stmts_for_value = old_expr_stmts_for_value;
3140 last_expr_value = old_last_expr_value;
3141 last_expr_type = old_last_expr_type;
3143 /* Restore the stack level. */
3145 if (reachable && thisblock->data.block.stack_level != 0)
3147 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3148 thisblock->data.block.stack_level, NULL_RTX);
3149 if (nonlocal_goto_handler_slot != 0)
3150 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3154 /* Any gotos out of this block must also do these things.
3155 Also report any gotos with fixups that came to labels in this
3157 fixup_gotos (thisblock,
3158 thisblock->data.block.stack_level,
3159 thisblock->data.block.cleanups,
3160 thisblock->data.block.first_insn,
3164 /* Mark the beginning and end of the scope if requested.
3165 We do this now, after running cleanups on the variables
3166 just going out of scope, so they are in scope for their cleanups. */
3169 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3171 /* Get rid of the beginning-mark if we don't make an end-mark. */
3172 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3174 /* If doing stupid register allocation, make sure lives of all
3175 register variables declared here extend thru end of scope. */
3178 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3180 rtx rtl = DECL_RTL (decl);
3181 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3185 /* Restore block_stack level for containing block. */
3187 stack_block_stack = thisblock->data.block.innermost_stack_block;
3188 POPSTACK (block_stack);
3190 /* Pop the stack slot nesting and free any slots at this level. */
3195 /* End a binding contour.
3196 VARS is the chain of VAR_DECL nodes for the variables bound
3197 in this contour. MARK_ENDS is nonzer if we should put a note
3198 at the beginning and end of this binding contour.
3199 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3203 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3208 struct nesting *thisbind = nesting_stack;
3212 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3213 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3214 warning_with_decl (decl, "unused variable `%s'");
3216 if (thisbind->exit_label)
3217 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3219 /* Pop block/bindings off stack */
3220 POPSTACK (block_stack);
3223 /* Generate RTL for the automatic variable declaration DECL.
3224 (Other kinds of declarations are simply ignored if seen here.)
3225 CLEANUP is an expression to be executed at exit from this binding contour;
3226 for example, in C++, it might call the destructor for this variable.
3228 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3229 either before or after calling `expand_decl' but before compiling
3230 any subsequent expressions. This is because CLEANUP may be expanded
3231 more than once, on different branches of execution.
3232 For the same reason, CLEANUP may not contain a CALL_EXPR
3233 except as its topmost node--else `preexpand_calls' would get confused.
3235 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3236 that is not associated with any particular variable.
3238 There is no special support here for C++ constructors.
3239 They should be handled by the proper code in DECL_INITIAL. */
3245 struct nesting *thisblock = block_stack;
3248 if (output_bytecode)
3250 bc_expand_decl (decl, 0);
3254 type = TREE_TYPE (decl);
3256 /* Only automatic variables need any expansion done.
3257 Static and external variables, and external functions,
3258 will be handled by `assemble_variable' (called from finish_decl).
3259 TYPE_DECL and CONST_DECL require nothing.
3260 PARM_DECLs are handled in `assign_parms'. */
3262 if (TREE_CODE (decl) != VAR_DECL)
3264 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3267 /* Create the RTL representation for the variable. */
3269 if (type == error_mark_node)
3270 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3271 else if (DECL_SIZE (decl) == 0)
3272 /* Variable with incomplete type. */
3274 if (DECL_INITIAL (decl) == 0)
3275 /* Error message was already done; now avoid a crash. */
3276 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3278 /* An initializer is going to decide the size of this array.
3279 Until we know the size, represent its address with a reg. */
3280 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3281 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3283 else if (DECL_MODE (decl) != BLKmode
3284 /* If -ffloat-store, don't put explicit float vars
3286 && !(flag_float_store
3287 && TREE_CODE (type) == REAL_TYPE)
3288 && ! TREE_THIS_VOLATILE (decl)
3289 && ! TREE_ADDRESSABLE (decl)
3290 && (DECL_REGISTER (decl) || ! obey_regdecls))
3292 /* Automatic variable that can go in a register. */
3293 int unsignedp = TREE_UNSIGNED (type);
3294 enum machine_mode reg_mode
3295 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3297 if (TREE_CODE (type) == COMPLEX_TYPE)
3299 rtx realpart, imagpart;
3300 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3302 /* For a complex type variable, make a CONCAT of two pseudos
3303 so that the real and imaginary parts
3304 can be allocated separately. */
3305 realpart = gen_reg_rtx (partmode);
3306 REG_USERVAR_P (realpart) = 1;
3307 imagpart = gen_reg_rtx (partmode);
3308 REG_USERVAR_P (imagpart) = 1;
3309 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3313 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3314 if (TREE_CODE (type) == POINTER_TYPE)
3315 mark_reg_pointer (DECL_RTL (decl));
3316 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3319 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3321 /* Variable of fixed size that goes on the stack. */
3325 /* If we previously made RTL for this decl, it must be an array
3326 whose size was determined by the initializer.
3327 The old address was a register; set that register now
3328 to the proper address. */
3329 if (DECL_RTL (decl) != 0)
3331 if (GET_CODE (DECL_RTL (decl)) != MEM
3332 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3334 oldaddr = XEXP (DECL_RTL (decl), 0);
3338 = assign_stack_temp (DECL_MODE (decl),
3339 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3340 + BITS_PER_UNIT - 1)
3343 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3345 /* Set alignment we actually gave this decl. */
3346 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3347 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3351 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3352 if (addr != oldaddr)
3353 emit_move_insn (oldaddr, addr);
3356 /* If this is a memory ref that contains aggregate components,
3357 mark it as such for cse and loop optimize. */
3358 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3360 /* If this is in memory because of -ffloat-store,
3361 set the volatile bit, to prevent optimizations from
3362 undoing the effects. */
3363 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3364 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3368 /* Dynamic-size object: must push space on the stack. */
3372 /* Record the stack pointer on entry to block, if have
3373 not already done so. */
3374 if (thisblock->data.block.stack_level == 0)
3376 do_pending_stack_adjust ();
3377 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3378 &thisblock->data.block.stack_level,
3379 thisblock->data.block.first_insn);
3380 stack_block_stack = thisblock;
3383 /* Compute the variable's size, in bytes. */
3384 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3386 size_int (BITS_PER_UNIT)),
3387 NULL_RTX, VOIDmode, 0);
3390 /* Allocate space on the stack for the variable. */
3391 address = allocate_dynamic_stack_space (size, NULL_RTX,
3394 /* Reference the variable indirect through that rtx. */
3395 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3397 /* If this is a memory ref that contains aggregate components,
3398 mark it as such for cse and loop optimize. */
3399 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3401 /* Indicate the alignment we actually gave this variable. */
3402 #ifdef STACK_BOUNDARY
3403 DECL_ALIGN (decl) = STACK_BOUNDARY;
3405 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3409 if (TREE_THIS_VOLATILE (decl))
3410 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3411 #if 0 /* A variable is not necessarily unchanging
3412 just because it is const. RTX_UNCHANGING_P
3413 means no change in the function,
3414 not merely no change in the variable's scope.
3415 It is correct to set RTX_UNCHANGING_P if the variable's scope
3416 is the whole function. There's no convenient way to test that. */
3417 if (TREE_READONLY (decl))
3418 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3421 /* If doing stupid register allocation, make sure life of any
3422 register variable starts here, at the start of its scope. */
3425 use_variable (DECL_RTL (decl));
3429 /* Generate code for the automatic variable declaration DECL. For
3430 most variables this just means we give it a stack offset. The
3431 compiler sometimes emits cleanups without variables and we will
3432 have to deal with those too. */
3435 bc_expand_decl (decl, cleanup)
3443 /* A cleanup with no variable. */
3450 /* Only auto variables need any work. */
3451 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3454 type = TREE_TYPE (decl);
3456 if (type == error_mark_node)
3457 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3459 else if (DECL_SIZE (decl) == 0)
3461 /* Variable with incomplete type. The stack offset herein will be
3462 fixed later in expand_decl_init (). */
3463 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3465 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3467 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3471 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3474 /* Emit code to perform the initialization of a declaration DECL. */
3477 expand_decl_init (decl)
3480 int was_used = TREE_USED (decl);
3482 if (output_bytecode)
3484 bc_expand_decl_init (decl);
3488 /* If this is a CONST_DECL, we don't have to generate any code, but
3489 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3490 to be set while in the obstack containing the constant. If we don't
3491 do this, we can lose if we have functions nested three deep and the middle
3492 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3493 the innermost function is the first to expand that STRING_CST. */
3494 if (TREE_CODE (decl) == CONST_DECL)
3496 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3497 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3498 EXPAND_INITIALIZER);
3502 if (TREE_STATIC (decl))
3505 /* Compute and store the initial value now. */
3507 if (DECL_INITIAL (decl) == error_mark_node)
3509 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3510 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3511 || code == POINTER_TYPE)
3512 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3516 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3518 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3519 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3523 /* Don't let the initialization count as "using" the variable. */
3524 TREE_USED (decl) = was_used;
3526 /* Free any temporaries we made while initializing the decl. */
3527 preserve_temp_slots (NULL_RTX);
3531 /* Expand initialization for variable-sized types. Allocate array
3532 using newlocalSI and set local variable, which is a pointer to the
3536 bc_expand_variable_local_init (decl)
3539 /* Evaluate size expression and coerce to SI */
3540 bc_expand_expr (DECL_SIZE (decl));
3542 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3543 no coercion is necessary (?) */
3545 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3546 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3548 /* Emit code to allocate array */
3549 bc_emit_instruction (newlocalSI);
3551 /* Store array pointer in local variable. This is the only instance
3552 where we actually want the address of the pointer to the
3553 variable-size block, rather than the pointer itself. We avoid
3554 using expand_address() since that would cause the pointer to be
3555 pushed rather than its address. Hence the hard-coded reference;
3556 notice also that the variable is always local (no global
3557 variable-size type variables). */
3559 bc_load_localaddr (DECL_RTL (decl));
3560 bc_emit_instruction (storeP);
3564 /* Emit code to initialize a declaration. */
3567 bc_expand_decl_init (decl)
3570 int org_stack_depth;
3572 /* Statical initializers are handled elsewhere */
3574 if (TREE_STATIC (decl))
3577 /* Memory original stack depth */
3578 org_stack_depth = stack_depth;
3580 /* If the type is variable-size, we first create its space (we ASSUME
3581 it CAN'T be static). We do this regardless of whether there's an
3582 initializer assignment or not. */
3584 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3585 bc_expand_variable_local_init (decl);
3587 /* Expand initializer assignment */
3588 if (DECL_INITIAL (decl) == error_mark_node)
3590 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3592 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3593 || code == POINTER_TYPE)
3595 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3597 else if (DECL_INITIAL (decl))
3598 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3600 /* Restore stack depth */
3601 if (org_stack_depth > stack_depth)
3604 bc_adjust_stack (stack_depth - org_stack_depth);
3608 /* CLEANUP is an expression to be executed at exit from this binding contour;
3609 for example, in C++, it might call the destructor for this variable.
3611 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3612 either before or after calling `expand_decl' but before compiling
3613 any subsequent expressions. This is because CLEANUP may be expanded
3614 more than once, on different branches of execution.
3615 For the same reason, CLEANUP may not contain a CALL_EXPR
3616 except as its topmost node--else `preexpand_calls' would get confused.
3618 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3619 that is not associated with any particular variable. */
3622 expand_decl_cleanup (decl, cleanup)
3625 struct nesting *thisblock = block_stack;
3627 /* Error if we are not in any block. */
3631 /* Record the cleanup if there is one. */
3635 thisblock->data.block.cleanups
3636 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3637 /* If this block has a cleanup, it belongs in stack_block_stack. */
3638 stack_block_stack = thisblock;
3639 (*interim_eh_hook) (NULL_TREE);
3644 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3645 DECL_ELTS is the list of elements that belong to DECL's type.
3646 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3649 expand_anon_union_decl (decl, cleanup, decl_elts)
3650 tree decl, cleanup, decl_elts;
3652 struct nesting *thisblock = block_stack;
3655 expand_decl (decl, cleanup);
3656 x = DECL_RTL (decl);
3660 tree decl_elt = TREE_VALUE (decl_elts);
3661 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3662 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3664 /* Propagate the union's alignment to the elements. */
3665 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3667 /* If the element has BLKmode and the union doesn't, the union is
3668 aligned such that the element doesn't need to have BLKmode, so
3669 change the element's mode to the appropriate one for its size. */
3670 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3671 DECL_MODE (decl_elt) = mode
3672 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3675 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3676 instead create a new MEM rtx with the proper mode. */
3677 if (GET_CODE (x) == MEM)
3679 if (mode == GET_MODE (x))
3680 DECL_RTL (decl_elt) = x;
3683 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3684 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3685 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3688 else if (GET_CODE (x) == REG)
3690 if (mode == GET_MODE (x))
3691 DECL_RTL (decl_elt) = x;
3693 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3698 /* Record the cleanup if there is one. */
3701 thisblock->data.block.cleanups
3702 = temp_tree_cons (decl_elt, cleanup_elt,
3703 thisblock->data.block.cleanups);
3705 decl_elts = TREE_CHAIN (decl_elts);
3709 /* Expand a list of cleanups LIST.
3710 Elements may be expressions or may be nested lists.
3712 If DONT_DO is nonnull, then any list-element
3713 whose TREE_PURPOSE matches DONT_DO is omitted.
3714 This is sometimes used to avoid a cleanup associated with
3715 a value that is being returned out of the scope.
3717 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3718 goto and handle protection regions specially in that case.
3720 If REACHABLE, we emit code, otherwise just inform the exception handling
3721 code about this finalization. */
3724 expand_cleanups (list, dont_do, in_fixup, reachable)
3731 for (tail = list; tail; tail = TREE_CHAIN (tail))
3732 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3734 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3735 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3739 (*interim_eh_hook) (TREE_VALUE (tail));
3743 /* Cleanups may be run multiple times. For example,
3744 when exiting a binding contour, we expand the
3745 cleanups associated with that contour. When a goto
3746 within that binding contour has a target outside that
3747 contour, it will expand all cleanups from its scope to
3748 the target. Though the cleanups are expanded multiple
3749 times, the control paths are non-overlapping so the
3750 cleanups will not be executed twice. */
3751 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3758 /* Move all cleanups from the current block_stack
3759 to the containing block_stack, where they are assumed to
3760 have been created. If anything can cause a temporary to
3761 be created, but not expanded for more than one level of
3762 block_stacks, then this code will have to change. */
3767 struct nesting *block = block_stack;
3768 struct nesting *outer = block->next;
3770 outer->data.block.cleanups
3771 = chainon (block->data.block.cleanups,
3772 outer->data.block.cleanups);
3773 block->data.block.cleanups = 0;
3777 last_cleanup_this_contour ()
3779 if (block_stack == 0)
3782 return block_stack->data.block.cleanups;
3785 /* Return 1 if there are any pending cleanups at this point.
3786 If THIS_CONTOUR is nonzero, check the current contour as well.
3787 Otherwise, look only at the contours that enclose this one. */
3790 any_pending_cleanups (this_contour)
3793 struct nesting *block;
3795 if (block_stack == 0)
3798 if (this_contour && block_stack->data.block.cleanups != NULL)
3800 if (block_stack->data.block.cleanups == 0
3801 && (block_stack->data.block.outer_cleanups == 0
3803 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3808 for (block = block_stack->next; block; block = block->next)
3809 if (block->data.block.cleanups != 0)
3815 /* Enter a case (Pascal) or switch (C) statement.
3816 Push a block onto case_stack and nesting_stack
3817 to accumulate the case-labels that are seen
3818 and to record the labels generated for the statement.
3820 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3821 Otherwise, this construct is transparent for `exit_something'.
3823 EXPR is the index-expression to be dispatched on.
3824 TYPE is its nominal type. We could simply convert EXPR to this type,
3825 but instead we take short cuts. */
3828 expand_start_case (exit_flag, expr, type, printname)
3834 register struct nesting *thiscase = ALLOC_NESTING ();
3836 /* Make an entry on case_stack for the case we are entering. */
3838 thiscase->next = case_stack;
3839 thiscase->all = nesting_stack;
3840 thiscase->depth = ++nesting_depth;
3841 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3842 thiscase->data.case_stmt.case_list = 0;
3843 thiscase->data.case_stmt.index_expr = expr;
3844 thiscase->data.case_stmt.nominal_type = type;
3845 thiscase->data.case_stmt.default_label = 0;
3846 thiscase->data.case_stmt.num_ranges = 0;
3847 thiscase->data.case_stmt.printname = printname;
3848 thiscase->data.case_stmt.seenlabel = 0;
3849 case_stack = thiscase;
3850 nesting_stack = thiscase;
3852 if (output_bytecode)
3854 bc_expand_start_case (thiscase, expr, type, printname);
3858 do_pending_stack_adjust ();
3860 /* Make sure case_stmt.start points to something that won't
3861 need any transformation before expand_end_case. */
3862 if (GET_CODE (get_last_insn ()) != NOTE)
3863 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3865 thiscase->data.case_stmt.start = get_last_insn ();
3869 /* Enter a case statement. It is assumed that the caller has pushed
3870 the current context onto the case stack. */
3873 bc_expand_start_case (thiscase, expr, type, printname)
3874 struct nesting *thiscase;
3879 bc_expand_expr (expr);
3880 bc_expand_conversion (TREE_TYPE (expr), type);
3882 /* For cases, the skip is a place we jump to that's emitted after
3883 the size of the jump table is known. */
3885 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3886 bc_emit_bytecode (jump);
3887 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3889 #ifdef DEBUG_PRINT_CODE
3890 fputc ('\n', stderr);
3895 /* Start a "dummy case statement" within which case labels are invalid
3896 and are not connected to any larger real case statement.
3897 This can be used if you don't want to let a case statement jump
3898 into the middle of certain kinds of constructs. */
3901 expand_start_case_dummy ()
3903 register struct nesting *thiscase = ALLOC_NESTING ();
3905 /* Make an entry on case_stack for the dummy. */
3907 thiscase->next = case_stack;
3908 thiscase->all = nesting_stack;
3909 thiscase->depth = ++nesting_depth;
3910 thiscase->exit_label = 0;
3911 thiscase->data.case_stmt.case_list = 0;
3912 thiscase->data.case_stmt.start = 0;
3913 thiscase->data.case_stmt.nominal_type = 0;
3914 thiscase->data.case_stmt.default_label = 0;
3915 thiscase->data.case_stmt.num_ranges = 0;
3916 case_stack = thiscase;
3917 nesting_stack = thiscase;
3920 /* End a dummy case statement. */
3923 expand_end_case_dummy ()
3925 POPSTACK (case_stack);
3928 /* Return the data type of the index-expression
3929 of the innermost case statement, or null if none. */
3932 case_index_expr_type ()
3935 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3939 /* Accumulate one case or default label inside a case or switch statement.
3940 VALUE is the value of the case (a null pointer, for a default label).
3941 The function CONVERTER, when applied to arguments T and V,
3942 converts the value V to the type T.
3944 If not currently inside a case or switch statement, return 1 and do
3945 nothing. The caller will print a language-specific error message.
3946 If VALUE is a duplicate or overlaps, return 2 and do nothing
3947 except store the (first) duplicate node in *DUPLICATE.
3948 If VALUE is out of range, return 3 and do nothing.
3949 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3950 Return 0 on success.
3952 Extended to handle range statements. */
3955 pushcase (value, converter, label, duplicate)
3956 register tree value;
3957 tree (*converter) PROTO((tree, tree));
3958 register tree label;
3961 register struct case_node **l;
3962 register struct case_node *n;
3966 if (output_bytecode)
3967 return bc_pushcase (value, label);
3969 /* Fail if not inside a real case statement. */
3970 if (! (case_stack && case_stack->data.case_stmt.start))
3973 if (stack_block_stack
3974 && stack_block_stack->depth > case_stack->depth)
3977 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
3978 nominal_type = case_stack->data.case_stmt.nominal_type;
3980 /* If the index is erroneous, avoid more problems: pretend to succeed. */
3981 if (index_type == error_mark_node)
3984 /* Convert VALUE to the type in which the comparisons are nominally done. */
3986 value = (*converter) (nominal_type, value);
3988 /* If this is the first label, warn if any insns have been emitted. */
3989 if (case_stack->data.case_stmt.seenlabel == 0)
3992 for (insn = case_stack->data.case_stmt.start;
3994 insn = NEXT_INSN (insn))
3996 if (GET_CODE (insn) == CODE_LABEL)
3998 if (GET_CODE (insn) != NOTE
3999 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4001 warning ("unreachable code at beginning of %s",
4002 case_stack->data.case_stmt.printname);
4007 case_stack->data.case_stmt.seenlabel = 1;
4009 /* Fail if this value is out of range for the actual type of the index
4010 (which may be narrower than NOMINAL_TYPE). */
4011 if (value != 0 && ! int_fits_type_p (value, index_type))
4014 /* Fail if this is a duplicate or overlaps another entry. */
4017 if (case_stack->data.case_stmt.default_label != 0)
4019 *duplicate = case_stack->data.case_stmt.default_label;
4022 case_stack->data.case_stmt.default_label = label;
4026 /* Find the elt in the chain before which to insert the new value,
4027 to keep the chain sorted in increasing order.
4028 But report an error if this element is a duplicate. */
4029 for (l = &case_stack->data.case_stmt.case_list;
4030 /* Keep going past elements distinctly less than VALUE. */
4031 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4036 /* Element we will insert before must be distinctly greater;
4037 overlap means error. */
4038 if (! tree_int_cst_lt (value, (*l)->low))
4040 *duplicate = (*l)->code_label;
4045 /* Add this label to the chain, and succeed.
4046 Copy VALUE so it is on temporary rather than momentary
4047 obstack and will thus survive till the end of the case statement. */
4048 n = (struct case_node *) oballoc (sizeof (struct case_node));
4051 n->high = n->low = copy_node (value);
4052 n->code_label = label;
4056 expand_label (label);
4060 /* Like pushcase but this case applies to all values
4061 between VALUE1 and VALUE2 (inclusive).
4062 The return value is the same as that of pushcase
4063 but there is one additional error code:
4064 4 means the specified range was empty. */
4067 pushcase_range (value1, value2, converter, label, duplicate)
4068 register tree value1, value2;
4069 tree (*converter) PROTO((tree, tree));
4070 register tree label;
4073 register struct case_node **l;
4074 register struct case_node *n;
4078 /* Fail if not inside a real case statement. */
4079 if (! (case_stack && case_stack->data.case_stmt.start))
4082 if (stack_block_stack
4083 && stack_block_stack->depth > case_stack->depth)
4086 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4087 nominal_type = case_stack->data.case_stmt.nominal_type;
4089 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4090 if (index_type == error_mark_node)
4093 /* If this is the first label, warn if any insns have been emitted. */
4094 if (case_stack->data.case_stmt.seenlabel == 0)
4097 for (insn = case_stack->data.case_stmt.start;
4099 insn = NEXT_INSN (insn))
4101 if (GET_CODE (insn) == CODE_LABEL)
4103 if (GET_CODE (insn) != NOTE
4104 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4106 warning ("unreachable code at beginning of %s",
4107 case_stack->data.case_stmt.printname);
4112 case_stack->data.case_stmt.seenlabel = 1;
4114 /* Convert VALUEs to type in which the comparisons are nominally done. */
4115 if (value1 == 0) /* Negative infinity. */
4116 value1 = TYPE_MIN_VALUE(index_type);
4117 value1 = (*converter) (nominal_type, value1);
4119 if (value2 == 0) /* Positive infinity. */
4120 value2 = TYPE_MAX_VALUE(index_type);
4121 value2 = (*converter) (nominal_type, value2);
4123 /* Fail if these values are out of range. */
4124 if (! int_fits_type_p (value1, index_type))
4127 if (! int_fits_type_p (value2, index_type))
4130 /* Fail if the range is empty. */
4131 if (tree_int_cst_lt (value2, value1))
4134 /* If the bounds are equal, turn this into the one-value case. */
4135 if (tree_int_cst_equal (value1, value2))
4136 return pushcase (value1, converter, label, duplicate);
4138 /* Find the elt in the chain before which to insert the new value,
4139 to keep the chain sorted in increasing order.
4140 But report an error if this element is a duplicate. */
4141 for (l = &case_stack->data.case_stmt.case_list;
4142 /* Keep going past elements distinctly less than this range. */
4143 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4148 /* Element we will insert before must be distinctly greater;
4149 overlap means error. */
4150 if (! tree_int_cst_lt (value2, (*l)->low))
4152 *duplicate = (*l)->code_label;
4157 /* Add this label to the chain, and succeed.
4158 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4159 obstack and will thus survive till the end of the case statement. */
4161 n = (struct case_node *) oballoc (sizeof (struct case_node));
4164 n->low = copy_node (value1);
4165 n->high = copy_node (value2);
4166 n->code_label = label;
4169 expand_label (label);
4171 case_stack->data.case_stmt.num_ranges++;
4177 /* Accumulate one case or default label; VALUE is the value of the
4178 case, or nil for a default label. If not currently inside a case,
4179 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4180 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4181 Return 0 on success. This function is a leftover from the earlier
4182 bytecode compiler, which was based on gcc 1.37. It should be
4183 merged into pushcase. */
4186 bc_pushcase (value, label)
4190 struct nesting *thiscase = case_stack;
4191 struct case_node *case_label, *new_label;
4196 /* Fail if duplicate, overlap, or out of type range. */
4199 value = convert (thiscase->data.case_stmt.nominal_type, value);
4200 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4203 for (case_label = thiscase->data.case_stmt.case_list;
4204 case_label->left; case_label = case_label->left)
4205 if (! tree_int_cst_lt (case_label->left->high, value))
4208 if (case_label != thiscase->data.case_stmt.case_list
4209 && ! tree_int_cst_lt (case_label->high, value)
4210 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4213 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4214 new_label->low = new_label->high = copy_node (value);
4215 new_label->code_label = label;
4216 new_label->left = case_label->left;
4218 case_label->left = new_label;
4219 thiscase->data.case_stmt.num_ranges++;
4223 if (thiscase->data.case_stmt.default_label)
4225 thiscase->data.case_stmt.default_label = label;
4228 expand_label (label);
4232 /* Returns the number of possible values of TYPE.
4233 Returns -1 if the number is unknown or variable.
4234 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4235 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4236 do not increase monotonically (there may be duplicates);
4237 to 1 if the values increase monotonically, but not always by 1;
4238 otherwise sets it to 0. */
4241 all_cases_count (type, spareness)
4245 HOST_WIDE_INT count, count_high = 0;
4248 switch (TREE_CODE (type))
4255 count = 1 << BITS_PER_UNIT;
4259 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4260 || TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST)
4265 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4266 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4267 but with overflow checking. */
4268 tree mint = TYPE_MIN_VALUE (type);
4269 tree maxt = TYPE_MAX_VALUE (type);
4270 HOST_WIDE_INT lo, hi;
4271 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4273 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4275 add_double (lo, hi, 1, 0, &lo, &hi);
4276 if (hi != 0 || lo < 0)
4283 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4285 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4286 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4287 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4288 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4292 if (*spareness == 1)
4294 tree prev = TREE_VALUE (TYPE_VALUES (type));
4295 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4297 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4302 prev = TREE_VALUE (t);
4311 #define BITARRAY_TEST(ARRAY, INDEX) \
4312 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4313 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4314 #define BITARRAY_SET(ARRAY, INDEX) \
4315 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4316 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4318 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4319 with the case values we have seen, assuming the case expression
4321 SPARSENESS is as determined by all_cases_count.
4323 The time needed is propotional to COUNT, unless
4324 SPARSENESS is 2, in which case quadratic time is needed. */
4327 mark_seen_cases (type, cases_seen, count, sparseness)
4329 unsigned char *cases_seen;
4335 tree next_node_to_try = NULL_TREE;
4336 long next_node_offset = 0;
4338 register struct case_node *n;
4339 tree val = make_node (INTEGER_CST);
4340 TREE_TYPE (val) = type;
4341 for (n = case_stack->data.case_stmt.case_list; n;
4344 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4345 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4346 while ( ! tree_int_cst_lt (n->high, val))
4348 /* Calculate (into xlo) the "offset" of the integer (val).
4349 The element with lowest value has offset 0, the next smallest
4350 element has offset 1, etc. */
4352 HOST_WIDE_INT xlo, xhi;
4354 if (sparseness == 2)
4356 /* This less efficient loop is only needed to handle
4357 duplicate case values (multiple enum constants
4358 with the same value). */
4359 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4360 t = TREE_CHAIN (t), xlo++)
4362 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4363 BITARRAY_SET (cases_seen, xlo);
4368 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4370 /* The TYPE_VALUES will be in increasing order, so
4371 starting searching where we last ended. */
4372 t = next_node_to_try;
4373 xlo = next_node_offset;
4379 t = TYPE_VALUES (type);
4382 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4384 next_node_to_try = TREE_CHAIN (t);
4385 next_node_offset = xlo + 1;
4390 if (t == next_node_to_try)
4396 t = TYPE_MIN_VALUE (type);
4398 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4402 add_double (xlo, xhi,
4403 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4407 if (xhi == 0 && xlo >= 0 && xlo < count)
4408 BITARRAY_SET (cases_seen, xlo);
4410 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4412 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4417 /* Called when the index of a switch statement is an enumerated type
4418 and there is no default label.
4420 Checks that all enumeration literals are covered by the case
4421 expressions of a switch. Also, warn if there are any extra
4422 switch cases that are *not* elements of the enumerated type.
4424 If all enumeration literals were covered by the case expressions,
4425 turn one of the expressions into the default expression since it should
4426 not be possible to fall through such a switch. */
4429 check_for_full_enumeration_handling (type)
4432 register struct case_node *n;
4433 register struct case_node **l;
4434 register tree chain;
4437 /* True iff the selector type is a numbered set mode. */
4440 /* The number of possible selector values. */
4443 /* For each possible selector value. a one iff it has been matched
4444 by a case value alternative. */
4445 unsigned char *cases_seen;
4447 /* The allocated size of cases_seen, in chars. */
4451 if (output_bytecode)
4453 bc_check_for_full_enumeration_handling (type);
4460 size = all_cases_count (type, &sparseness);
4461 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4463 if (size > 0 && size < 600000
4464 /* We deliberately use malloc here - not xmalloc. */
4465 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4468 tree v = TYPE_VALUES (type);
4469 bzero (cases_seen, bytes_needed);
4471 /* The time complexity of this code is normally O(N), where
4472 N being the number of members in the enumerated type.
4473 However, if type is a ENUMERAL_TYPE whose values do not
4474 increase monotonically, quadratic time may be needed. */
4476 mark_seen_cases (type, cases_seen, size, sparseness);
4478 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4480 if (BITARRAY_TEST(cases_seen, i) == 0)
4481 warning ("enumeration value `%s' not handled in switch",
4482 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4488 /* Now we go the other way around; we warn if there are case
4489 expressions that don't correspond to enumerators. This can
4490 occur since C and C++ don't enforce type-checking of
4491 assignments to enumeration variables. */
4494 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4496 for (chain = TYPE_VALUES (type);
4497 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4498 chain = TREE_CHAIN (chain))
4503 if (TYPE_NAME (type) == 0)
4504 warning ("case value `%d' not in enumerated type",
4505 TREE_INT_CST_LOW (n->low));
4507 warning ("case value `%d' not in enumerated type `%s'",
4508 TREE_INT_CST_LOW (n->low),
4509 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4512 : DECL_NAME (TYPE_NAME (type))));
4514 if (!tree_int_cst_equal (n->low, n->high))
4516 for (chain = TYPE_VALUES (type);
4517 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4518 chain = TREE_CHAIN (chain))
4523 if (TYPE_NAME (type) == 0)
4524 warning ("case value `%d' not in enumerated type",
4525 TREE_INT_CST_LOW (n->high));
4527 warning ("case value `%d' not in enumerated type `%s'",
4528 TREE_INT_CST_LOW (n->high),
4529 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4532 : DECL_NAME (TYPE_NAME (type))));
4538 /* ??? This optimization is disabled because it causes valid programs to
4539 fail. ANSI C does not guarantee that an expression with enum type
4540 will have a value that is the same as one of the enumation literals. */
4542 /* If all values were found as case labels, make one of them the default
4543 label. Thus, this switch will never fall through. We arbitrarily pick
4544 the last one to make the default since this is likely the most
4545 efficient choice. */
4549 for (l = &case_stack->data.case_stmt.case_list;
4554 case_stack->data.case_stmt.default_label = (*l)->code_label;
4561 /* Check that all enumeration literals are covered by the case
4562 expressions of a switch. Also warn if there are any cases
4563 that are not elements of the enumerated type. */
4566 bc_check_for_full_enumeration_handling (type)
4569 struct nesting *thiscase = case_stack;
4570 struct case_node *c;
4573 /* Check for enums not handled. */
4574 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4576 for (c = thiscase->data.case_stmt.case_list->left;
4577 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4580 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4581 warning ("enumerated value `%s' not handled in switch",
4582 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4585 /* Check for cases not in the enumeration. */
4586 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4588 for (e = TYPE_VALUES (type);
4589 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4593 warning ("case value `%d' not in enumerated type `%s'",
4594 TREE_INT_CST_LOW (c->low),
4595 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4597 : DECL_NAME (TYPE_NAME (type))));
4601 /* Terminate a case (Pascal) or switch (C) statement
4602 in which ORIG_INDEX is the expression to be tested.
4603 Generate the code to test it and jump to the right place. */
4606 expand_end_case (orig_index)
4609 tree minval, maxval, range, orig_minval;
4610 rtx default_label = 0;
4611 register struct case_node *n;
4619 register struct nesting *thiscase = case_stack;
4620 tree index_expr, index_type;
4623 if (output_bytecode)
4625 bc_expand_end_case (orig_index);
4629 table_label = gen_label_rtx ();
4630 index_expr = thiscase->data.case_stmt.index_expr;
4631 index_type = TREE_TYPE (index_expr);
4632 unsignedp = TREE_UNSIGNED (index_type);
4634 do_pending_stack_adjust ();
4636 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4637 if (index_type != error_mark_node)
4639 /* If switch expression was an enumerated type, check that all
4640 enumeration literals are covered by the cases.
4641 No sense trying this if there's a default case, however. */
4643 if (!thiscase->data.case_stmt.default_label
4644 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4645 && TREE_CODE (index_expr) != INTEGER_CST)
4646 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4648 /* If this is the first label, warn if any insns have been emitted. */
4649 if (thiscase->data.case_stmt.seenlabel == 0)
4652 for (insn = get_last_insn ();
4653 insn != case_stack->data.case_stmt.start;
4654 insn = PREV_INSN (insn))
4655 if (GET_CODE (insn) != NOTE
4656 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4658 warning ("unreachable code at beginning of %s",
4659 case_stack->data.case_stmt.printname);
4664 /* If we don't have a default-label, create one here,
4665 after the body of the switch. */
4666 if (thiscase->data.case_stmt.default_label == 0)
4668 thiscase->data.case_stmt.default_label
4669 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4670 expand_label (thiscase->data.case_stmt.default_label);
4672 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4674 before_case = get_last_insn ();
4676 /* Simplify the case-list before we count it. */
4677 group_case_nodes (thiscase->data.case_stmt.case_list);
4679 /* Get upper and lower bounds of case values.
4680 Also convert all the case values to the index expr's data type. */
4683 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4685 /* Check low and high label values are integers. */
4686 if (TREE_CODE (n->low) != INTEGER_CST)
4688 if (TREE_CODE (n->high) != INTEGER_CST)
4691 n->low = convert (index_type, n->low);
4692 n->high = convert (index_type, n->high);
4694 /* Count the elements and track the largest and smallest
4695 of them (treating them as signed even if they are not). */
4703 if (INT_CST_LT (n->low, minval))
4705 if (INT_CST_LT (maxval, n->high))
4708 /* A range counts double, since it requires two compares. */
4709 if (! tree_int_cst_equal (n->low, n->high))
4713 orig_minval = minval;
4715 /* Compute span of values. */
4717 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4721 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4723 emit_jump (default_label);
4726 /* If range of values is much bigger than number of values,
4727 make a sequence of conditional branches instead of a dispatch.
4728 If the switch-index is a constant, do it this way
4729 because we can optimize it. */
4731 #ifndef CASE_VALUES_THRESHOLD
4733 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4735 /* If machine does not have a case insn that compares the
4736 bounds, this means extra overhead for dispatch tables
4737 which raises the threshold for using them. */
4738 #define CASE_VALUES_THRESHOLD 5
4739 #endif /* HAVE_casesi */
4740 #endif /* CASE_VALUES_THRESHOLD */
4742 else if (TREE_INT_CST_HIGH (range) != 0
4743 || count < CASE_VALUES_THRESHOLD
4744 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4746 || TREE_CODE (index_expr) == INTEGER_CST
4747 /* These will reduce to a constant. */
4748 || (TREE_CODE (index_expr) == CALL_EXPR
4749 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4750 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4751 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4752 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4753 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4755 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4757 /* If the index is a short or char that we do not have
4758 an insn to handle comparisons directly, convert it to
4759 a full integer now, rather than letting each comparison
4760 generate the conversion. */
4762 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4763 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4764 == CODE_FOR_nothing))
4766 enum machine_mode wider_mode;
4767 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4768 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4769 if (cmp_optab->handlers[(int) wider_mode].insn_code
4770 != CODE_FOR_nothing)
4772 index = convert_to_mode (wider_mode, index, unsignedp);
4778 do_pending_stack_adjust ();
4780 index = protect_from_queue (index, 0);
4781 if (GET_CODE (index) == MEM)
4782 index = copy_to_reg (index);
4783 if (GET_CODE (index) == CONST_INT
4784 || TREE_CODE (index_expr) == INTEGER_CST)
4786 /* Make a tree node with the proper constant value
4787 if we don't already have one. */
4788 if (TREE_CODE (index_expr) != INTEGER_CST)
4791 = build_int_2 (INTVAL (index),
4792 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4793 index_expr = convert (index_type, index_expr);
4796 /* For constant index expressions we need only
4797 issue a unconditional branch to the appropriate
4798 target code. The job of removing any unreachable
4799 code is left to the optimisation phase if the
4800 "-O" option is specified. */
4801 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4802 if (! tree_int_cst_lt (index_expr, n->low)
4803 && ! tree_int_cst_lt (n->high, index_expr))
4807 emit_jump (label_rtx (n->code_label));
4809 emit_jump (default_label);
4813 /* If the index expression is not constant we generate
4814 a binary decision tree to select the appropriate
4815 target code. This is done as follows:
4817 The list of cases is rearranged into a binary tree,
4818 nearly optimal assuming equal probability for each case.
4820 The tree is transformed into RTL, eliminating
4821 redundant test conditions at the same time.
4823 If program flow could reach the end of the
4824 decision tree an unconditional jump to the
4825 default code is emitted. */
4828 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4829 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4830 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4832 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4833 default_label, index_type);
4834 emit_jump_if_reachable (default_label);
4843 enum machine_mode index_mode = SImode;
4844 int index_bits = GET_MODE_BITSIZE (index_mode);
4846 enum machine_mode op_mode;
4848 /* Convert the index to SImode. */
4849 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4850 > GET_MODE_BITSIZE (index_mode))
4852 enum machine_mode omode = TYPE_MODE (index_type);
4853 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4855 /* We must handle the endpoints in the original mode. */
4856 index_expr = build (MINUS_EXPR, index_type,
4857 index_expr, minval);
4858 minval = integer_zero_node;
4859 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4860 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4861 emit_jump_insn (gen_bltu (default_label));
4862 /* Now we can safely truncate. */
4863 index = convert_to_mode (index_mode, index, 0);
4867 if (TYPE_MODE (index_type) != index_mode)
4869 index_expr = convert (type_for_size (index_bits, 0),
4871 index_type = TREE_TYPE (index_expr);
4874 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4877 index = protect_from_queue (index, 0);
4878 do_pending_stack_adjust ();
4880 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4881 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4883 index = copy_to_mode_reg (op_mode, index);
4885 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4887 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4888 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4890 op1 = copy_to_mode_reg (op_mode, op1);
4892 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4894 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4895 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4897 op2 = copy_to_mode_reg (op_mode, op2);
4899 emit_jump_insn (gen_casesi (index, op1, op2,
4900 table_label, default_label));
4904 #ifdef HAVE_tablejump
4905 if (! win && HAVE_tablejump)
4907 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4908 fold (build (MINUS_EXPR, index_type,
4909 index_expr, minval)));
4910 index_type = TREE_TYPE (index_expr);
4911 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4913 index = protect_from_queue (index, 0);
4914 do_pending_stack_adjust ();
4916 do_tablejump (index, TYPE_MODE (index_type),
4917 expand_expr (range, NULL_RTX, VOIDmode, 0),
4918 table_label, default_label);
4925 /* Get table of labels to jump to, in order of case index. */
4927 ncases = TREE_INT_CST_LOW (range) + 1;
4928 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4929 bzero ((char *) labelvec, ncases * sizeof (rtx));
4931 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4933 register HOST_WIDE_INT i
4934 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4939 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4940 if (i + TREE_INT_CST_LOW (orig_minval)
4941 == TREE_INT_CST_LOW (n->high))
4947 /* Fill in the gaps with the default. */
4948 for (i = 0; i < ncases; i++)
4949 if (labelvec[i] == 0)
4950 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4952 /* Output the table */
4953 emit_label (table_label);
4955 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
4956 were an expression, instead of an #ifdef/#ifndef. */
4958 #ifdef CASE_VECTOR_PC_RELATIVE
4962 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
4963 gen_rtx (LABEL_REF, Pmode, table_label),
4964 gen_rtvec_v (ncases, labelvec)));
4966 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
4967 gen_rtvec_v (ncases, labelvec)));
4969 /* If the case insn drops through the table,
4970 after the table we must jump to the default-label.
4971 Otherwise record no drop-through after the table. */
4972 #ifdef CASE_DROPS_THROUGH
4973 emit_jump (default_label);
4979 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
4980 reorder_insns (before_case, get_last_insn (),
4981 thiscase->data.case_stmt.start);
4984 if (thiscase->exit_label)
4985 emit_label (thiscase->exit_label);
4987 POPSTACK (case_stack);
4993 /* Terminate a case statement. EXPR is the original index
4997 bc_expand_end_case (expr)
5000 struct nesting *thiscase = case_stack;
5001 enum bytecode_opcode opcode;
5002 struct bc_label *jump_label;
5003 struct case_node *c;
5005 bc_emit_bytecode (jump);
5006 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5008 #ifdef DEBUG_PRINT_CODE
5009 fputc ('\n', stderr);
5012 /* Now that the size of the jump table is known, emit the actual
5013 indexed jump instruction. */
5014 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5016 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5017 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5018 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5020 bc_emit_bytecode (opcode);
5022 /* Now emit the case instructions literal arguments, in order.
5023 In addition to the value on the stack, it uses:
5024 1. The address of the jump table.
5025 2. The size of the jump table.
5026 3. The default label. */
5028 jump_label = bc_get_bytecode_label ();
5029 bc_emit_bytecode_labelref (jump_label);
5030 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5031 sizeof thiscase->data.case_stmt.num_ranges);
5033 if (thiscase->data.case_stmt.default_label)
5034 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5036 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5038 /* Output the jump table. */
5040 bc_align_bytecode (3 /* PTR_ALIGN */);
5041 bc_emit_bytecode_labeldef (jump_label);
5043 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5044 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5046 opcode = TREE_INT_CST_LOW (c->low);
5047 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5049 opcode = TREE_INT_CST_LOW (c->high);
5050 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5052 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5055 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5056 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5058 bc_emit_bytecode_DI_const (c->low);
5059 bc_emit_bytecode_DI_const (c->high);
5061 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5068 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5070 /* Possibly issue enumeration warnings. */
5072 if (!thiscase->data.case_stmt.default_label
5073 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5074 && TREE_CODE (expr) != INTEGER_CST
5076 check_for_full_enumeration_handling (TREE_TYPE (expr));
5079 #ifdef DEBUG_PRINT_CODE
5080 fputc ('\n', stderr);
5083 POPSTACK (case_stack);
5087 /* Return unique bytecode ID. */
5092 static int bc_uid = 0;
5097 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5100 do_jump_if_equal (op1, op2, label, unsignedp)
5101 rtx op1, op2, label;
5104 if (GET_CODE (op1) == CONST_INT
5105 && GET_CODE (op2) == CONST_INT)
5107 if (INTVAL (op1) == INTVAL (op2))
5112 enum machine_mode mode = GET_MODE (op1);
5113 if (mode == VOIDmode)
5114 mode = GET_MODE (op2);
5115 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5116 emit_jump_insn (gen_beq (label));
5120 /* Not all case values are encountered equally. This function
5121 uses a heuristic to weight case labels, in cases where that
5122 looks like a reasonable thing to do.
5124 Right now, all we try to guess is text, and we establish the
5127 chars above space: 16
5136 If we find any cases in the switch that are not either -1 or in the range
5137 of valid ASCII characters, or are control characters other than those
5138 commonly used with "\", don't treat this switch scanning text.
5140 Return 1 if these nodes are suitable for cost estimation, otherwise
5144 estimate_case_costs (node)
5147 tree min_ascii = build_int_2 (-1, -1);
5148 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5152 /* If we haven't already made the cost table, make it now. Note that the
5153 lower bound of the table is -1, not zero. */
5155 if (cost_table == NULL)
5157 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5158 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5160 for (i = 0; i < 128; i++)
5164 else if (ispunct (i))
5166 else if (iscntrl (i))
5170 cost_table[' '] = 8;
5171 cost_table['\t'] = 4;
5172 cost_table['\0'] = 4;
5173 cost_table['\n'] = 2;
5174 cost_table['\f'] = 1;
5175 cost_table['\v'] = 1;
5176 cost_table['\b'] = 1;
5179 /* See if all the case expressions look like text. It is text if the
5180 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5181 as signed arithmetic since we don't want to ever access cost_table with a
5182 value less than -1. Also check that none of the constants in a range
5183 are strange control characters. */
5185 for (n = node; n; n = n->right)
5187 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5190 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5191 if (cost_table[i] < 0)
5195 /* All interesting values are within the range of interesting
5196 ASCII characters. */
5200 /* Scan an ordered list of case nodes
5201 combining those with consecutive values or ranges.
5203 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5206 group_case_nodes (head)
5209 case_node_ptr node = head;
5213 rtx lb = next_real_insn (label_rtx (node->code_label));
5214 case_node_ptr np = node;
5216 /* Try to group the successors of NODE with NODE. */
5217 while (((np = np->right) != 0)
5218 /* Do they jump to the same place? */
5219 && next_real_insn (label_rtx (np->code_label)) == lb
5220 /* Are their ranges consecutive? */
5221 && tree_int_cst_equal (np->low,
5222 fold (build (PLUS_EXPR,
5223 TREE_TYPE (node->high),
5226 /* An overflow is not consecutive. */
5227 && tree_int_cst_lt (node->high,
5228 fold (build (PLUS_EXPR,
5229 TREE_TYPE (node->high),
5231 integer_one_node))))
5233 node->high = np->high;
5235 /* NP is the first node after NODE which can't be grouped with it.
5236 Delete the nodes in between, and move on to that node. */
5242 /* Take an ordered list of case nodes
5243 and transform them into a near optimal binary tree,
5244 on the assumption that any target code selection value is as
5245 likely as any other.
5247 The transformation is performed by splitting the ordered
5248 list into two equal sections plus a pivot. The parts are
5249 then attached to the pivot as left and right branches. Each
5250 branch is is then transformed recursively. */
5253 balance_case_nodes (head, parent)
5254 case_node_ptr *head;
5255 case_node_ptr parent;
5257 register case_node_ptr np;
5265 register case_node_ptr *npp;
5268 /* Count the number of entries on branch. Also count the ranges. */
5272 if (!tree_int_cst_equal (np->low, np->high))
5276 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5280 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5288 /* Split this list if it is long enough for that to help. */
5293 /* Find the place in the list that bisects the list's total cost,
5294 Here I gets half the total cost. */
5299 /* Skip nodes while their cost does not reach that amount. */
5300 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5301 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5302 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5305 npp = &(*npp)->right;
5310 /* Leave this branch lopsided, but optimize left-hand
5311 side and fill in `parent' fields for right-hand side. */
5313 np->parent = parent;
5314 balance_case_nodes (&np->left, np);
5315 for (; np->right; np = np->right)
5316 np->right->parent = np;
5320 /* If there are just three nodes, split at the middle one. */
5322 npp = &(*npp)->right;
5325 /* Find the place in the list that bisects the list's total cost,
5326 where ranges count as 2.
5327 Here I gets half the total cost. */
5328 i = (i + ranges + 1) / 2;
5331 /* Skip nodes while their cost does not reach that amount. */
5332 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5337 npp = &(*npp)->right;
5342 np->parent = parent;
5345 /* Optimize each of the two split parts. */
5346 balance_case_nodes (&np->left, np);
5347 balance_case_nodes (&np->right, np);
5351 /* Else leave this branch as one level,
5352 but fill in `parent' fields. */
5354 np->parent = parent;
5355 for (; np->right; np = np->right)
5356 np->right->parent = np;
5361 /* Search the parent sections of the case node tree
5362 to see if a test for the lower bound of NODE would be redundant.
5363 INDEX_TYPE is the type of the index expression.
5365 The instructions to generate the case decision tree are
5366 output in the same order as nodes are processed so it is
5367 known that if a parent node checks the range of the current
5368 node minus one that the current node is bounded at its lower
5369 span. Thus the test would be redundant. */
5372 node_has_low_bound (node, index_type)
5377 case_node_ptr pnode;
5379 /* If the lower bound of this node is the lowest value in the index type,
5380 we need not test it. */
5382 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5385 /* If this node has a left branch, the value at the left must be less
5386 than that at this node, so it cannot be bounded at the bottom and
5387 we need not bother testing any further. */
5392 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5393 node->low, integer_one_node));
5395 /* If the subtraction above overflowed, we can't verify anything.
5396 Otherwise, look for a parent that tests our value - 1. */
5398 if (! tree_int_cst_lt (low_minus_one, node->low))
5401 for (pnode = node->parent; pnode; pnode = pnode->parent)
5402 if (tree_int_cst_equal (low_minus_one, pnode->high))
5408 /* Search the parent sections of the case node tree
5409 to see if a test for the upper bound of NODE would be redundant.
5410 INDEX_TYPE is the type of the index expression.
5412 The instructions to generate the case decision tree are
5413 output in the same order as nodes are processed so it is
5414 known that if a parent node checks the range of the current
5415 node plus one that the current node is bounded at its upper
5416 span. Thus the test would be redundant. */
5419 node_has_high_bound (node, index_type)
5424 case_node_ptr pnode;
5426 /* If the upper bound of this node is the highest value in the type
5427 of the index expression, we need not test against it. */
5429 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5432 /* If this node has a right branch, the value at the right must be greater
5433 than that at this node, so it cannot be bounded at the top and
5434 we need not bother testing any further. */
5439 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5440 node->high, integer_one_node));
5442 /* If the addition above overflowed, we can't verify anything.
5443 Otherwise, look for a parent that tests our value + 1. */
5445 if (! tree_int_cst_lt (node->high, high_plus_one))
5448 for (pnode = node->parent; pnode; pnode = pnode->parent)
5449 if (tree_int_cst_equal (high_plus_one, pnode->low))
5455 /* Search the parent sections of the
5456 case node tree to see if both tests for the upper and lower
5457 bounds of NODE would be redundant. */
5460 node_is_bounded (node, index_type)
5464 return (node_has_low_bound (node, index_type)
5465 && node_has_high_bound (node, index_type));
5468 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5471 emit_jump_if_reachable (label)
5474 if (GET_CODE (get_last_insn ()) != BARRIER)
5478 /* Emit step-by-step code to select a case for the value of INDEX.
5479 The thus generated decision tree follows the form of the
5480 case-node binary tree NODE, whose nodes represent test conditions.
5481 INDEX_TYPE is the type of the index of the switch.
5483 Care is taken to prune redundant tests from the decision tree
5484 by detecting any boundary conditions already checked by
5485 emitted rtx. (See node_has_high_bound, node_has_low_bound
5486 and node_is_bounded, above.)
5488 Where the test conditions can be shown to be redundant we emit
5489 an unconditional jump to the target code. As a further
5490 optimization, the subordinates of a tree node are examined to
5491 check for bounded nodes. In this case conditional and/or
5492 unconditional jumps as a result of the boundary check for the
5493 current node are arranged to target the subordinates associated
5494 code for out of bound conditions on the current node node.
5496 We can assume that when control reaches the code generated here,
5497 the index value has already been compared with the parents
5498 of this node, and determined to be on the same side of each parent
5499 as this node is. Thus, if this node tests for the value 51,
5500 and a parent tested for 52, we don't need to consider
5501 the possibility of a value greater than 51. If another parent
5502 tests for the value 50, then this node need not test anything. */
5505 emit_case_nodes (index, node, default_label, index_type)
5511 /* If INDEX has an unsigned type, we must make unsigned branches. */
5512 int unsignedp = TREE_UNSIGNED (index_type);
5513 typedef rtx rtx_function ();
5514 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5515 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5516 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5517 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5518 enum machine_mode mode = GET_MODE (index);
5520 /* See if our parents have already tested everything for us.
5521 If they have, emit an unconditional jump for this node. */
5522 if (node_is_bounded (node, index_type))
5523 emit_jump (label_rtx (node->code_label));
5525 else if (tree_int_cst_equal (node->low, node->high))
5527 /* Node is single valued. First see if the index expression matches
5528 this node and then check our children, if any. */
5530 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5531 label_rtx (node->code_label), unsignedp);
5533 if (node->right != 0 && node->left != 0)
5535 /* This node has children on both sides.
5536 Dispatch to one side or the other
5537 by comparing the index value with this node's value.
5538 If one subtree is bounded, check that one first,
5539 so we can avoid real branches in the tree. */
5541 if (node_is_bounded (node->right, index_type))
5543 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5545 GT, NULL_RTX, mode, unsignedp, 0);
5547 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5548 emit_case_nodes (index, node->left, default_label, index_type);
5551 else if (node_is_bounded (node->left, index_type))
5553 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5555 LT, NULL_RTX, mode, unsignedp, 0);
5556 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5557 emit_case_nodes (index, node->right, default_label, index_type);
5562 /* Neither node is bounded. First distinguish the two sides;
5563 then emit the code for one side at a time. */
5566 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5568 /* See if the value is on the right. */
5569 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5571 GT, NULL_RTX, mode, unsignedp, 0);
5572 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5574 /* Value must be on the left.
5575 Handle the left-hand subtree. */
5576 emit_case_nodes (index, node->left, default_label, index_type);
5577 /* If left-hand subtree does nothing,
5579 emit_jump_if_reachable (default_label);
5581 /* Code branches here for the right-hand subtree. */
5582 expand_label (test_label);
5583 emit_case_nodes (index, node->right, default_label, index_type);
5587 else if (node->right != 0 && node->left == 0)
5589 /* Here we have a right child but no left so we issue conditional
5590 branch to default and process the right child.
5592 Omit the conditional branch to default if we it avoid only one
5593 right child; it costs too much space to save so little time. */
5595 if (node->right->right || node->right->left
5596 || !tree_int_cst_equal (node->right->low, node->right->high))
5598 if (!node_has_low_bound (node, index_type))
5600 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5602 LT, NULL_RTX, mode, unsignedp, 0);
5603 emit_jump_insn ((*gen_blt_pat) (default_label));
5606 emit_case_nodes (index, node->right, default_label, index_type);
5609 /* We cannot process node->right normally
5610 since we haven't ruled out the numbers less than
5611 this node's value. So handle node->right explicitly. */
5612 do_jump_if_equal (index,
5613 expand_expr (node->right->low, NULL_RTX,
5615 label_rtx (node->right->code_label), unsignedp);
5618 else if (node->right == 0 && node->left != 0)
5620 /* Just one subtree, on the left. */
5622 #if 0 /* The following code and comment were formerly part
5623 of the condition here, but they didn't work
5624 and I don't understand what the idea was. -- rms. */
5625 /* If our "most probable entry" is less probable
5626 than the default label, emit a jump to
5627 the default label using condition codes
5628 already lying around. With no right branch,
5629 a branch-greater-than will get us to the default
5632 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5635 if (node->left->left || node->left->right
5636 || !tree_int_cst_equal (node->left->low, node->left->high))
5638 if (!node_has_high_bound (node, index_type))
5640 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5642 GT, NULL_RTX, mode, unsignedp, 0);
5643 emit_jump_insn ((*gen_bgt_pat) (default_label));
5646 emit_case_nodes (index, node->left, default_label, index_type);
5649 /* We cannot process node->left normally
5650 since we haven't ruled out the numbers less than
5651 this node's value. So handle node->left explicitly. */
5652 do_jump_if_equal (index,
5653 expand_expr (node->left->low, NULL_RTX,
5655 label_rtx (node->left->code_label), unsignedp);
5660 /* Node is a range. These cases are very similar to those for a single
5661 value, except that we do not start by testing whether this node
5662 is the one to branch to. */
5664 if (node->right != 0 && node->left != 0)
5666 /* Node has subtrees on both sides.
5667 If the right-hand subtree is bounded,
5668 test for it first, since we can go straight there.
5669 Otherwise, we need to make a branch in the control structure,
5670 then handle the two subtrees. */
5671 tree test_label = 0;
5673 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5675 GT, NULL_RTX, mode, unsignedp, 0);
5677 if (node_is_bounded (node->right, index_type))
5678 /* Right hand node is fully bounded so we can eliminate any
5679 testing and branch directly to the target code. */
5680 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5683 /* Right hand node requires testing.
5684 Branch to a label where we will handle it later. */
5686 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5687 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5690 /* Value belongs to this node or to the left-hand subtree. */
5692 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5693 GE, NULL_RTX, mode, unsignedp, 0);
5694 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5696 /* Handle the left-hand subtree. */
5697 emit_case_nodes (index, node->left, default_label, index_type);
5699 /* If right node had to be handled later, do that now. */
5703 /* If the left-hand subtree fell through,
5704 don't let it fall into the right-hand subtree. */
5705 emit_jump_if_reachable (default_label);
5707 expand_label (test_label);
5708 emit_case_nodes (index, node->right, default_label, index_type);
5712 else if (node->right != 0 && node->left == 0)
5714 /* Deal with values to the left of this node,
5715 if they are possible. */
5716 if (!node_has_low_bound (node, index_type))
5718 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5720 LT, NULL_RTX, mode, unsignedp, 0);
5721 emit_jump_insn ((*gen_blt_pat) (default_label));
5724 /* Value belongs to this node or to the right-hand subtree. */
5726 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5728 LE, NULL_RTX, mode, unsignedp, 0);
5729 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5731 emit_case_nodes (index, node->right, default_label, index_type);
5734 else if (node->right == 0 && node->left != 0)
5736 /* Deal with values to the right of this node,
5737 if they are possible. */
5738 if (!node_has_high_bound (node, index_type))
5740 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5742 GT, NULL_RTX, mode, unsignedp, 0);
5743 emit_jump_insn ((*gen_bgt_pat) (default_label));
5746 /* Value belongs to this node or to the left-hand subtree. */
5748 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5749 GE, NULL_RTX, mode, unsignedp, 0);
5750 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5752 emit_case_nodes (index, node->left, default_label, index_type);
5757 /* Node has no children so we check low and high bounds to remove
5758 redundant tests. Only one of the bounds can exist,
5759 since otherwise this node is bounded--a case tested already. */
5761 if (!node_has_high_bound (node, index_type))
5763 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5765 GT, NULL_RTX, mode, unsignedp, 0);
5766 emit_jump_insn ((*gen_bgt_pat) (default_label));
5769 if (!node_has_low_bound (node, index_type))
5771 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5773 LT, NULL_RTX, mode, unsignedp, 0);
5774 emit_jump_insn ((*gen_blt_pat) (default_label));
5777 emit_jump (label_rtx (node->code_label));
5782 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5783 so that the debugging info will be correct for the unrolled loop. */
5785 /* Indexed by block number, contains a pointer to the N'th block node. */
5787 static tree *block_vector;
5790 find_loop_tree_blocks ()
5792 tree block = DECL_INITIAL (current_function_decl);
5794 /* There first block is for the function body, and does not have
5795 corresponding block notes. Don't include it in the block vector. */
5796 block = BLOCK_SUBBLOCKS (block);
5798 block_vector = identify_blocks (block, get_insns ());
5802 unroll_block_trees ()
5804 tree block = DECL_INITIAL (current_function_decl);
5806 reorder_blocks (block_vector, block, get_insns ());