1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92, 93, 94, 1995 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file handles the generation of rtl code from tree structure
22 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
23 It also creates the rtl expressions for parameters and auto variables
24 and has full responsibility for allocating stack slots.
26 The functions whose names start with `expand_' are called by the
27 parser to generate RTL instructions for various kinds of constructs.
29 Some control and binding constructs require calling several such
30 functions at different times. For example, a simple if-then
31 is expanded by calling `expand_start_cond' (with the condition-expression
32 as argument) before parsing the then-clause and calling `expand_end_cond'
33 after parsing the then-clause. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
55 #include "bc-typecd.h"
56 #include "bc-opcode.h"
60 #define obstack_chunk_alloc xmalloc
61 #define obstack_chunk_free free
62 struct obstack stmt_obstack;
64 /* Filename and line number of last line-number note,
65 whether we actually emitted it or not. */
69 /* Nonzero if within a ({...}) grouping, in which case we must
70 always compute a value for each expr-stmt in case it is the last one. */
72 int expr_stmts_for_value;
74 /* Each time we expand an expression-statement,
75 record the expr's type and its RTL value here. */
77 static tree last_expr_type;
78 static rtx last_expr_value;
80 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
81 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
82 This is used by the `remember_end_note' function to record the endpoint
83 of each generated block in its associated BLOCK node. */
85 static rtx last_block_end_note;
87 /* Number of binding contours started so far in this function. */
89 int block_start_count;
91 /* Nonzero if function being compiled needs to
92 return the address of where it has put a structure value. */
94 extern int current_function_returns_pcc_struct;
96 /* Label that will go on parm cleanup code, if any.
97 Jumping to this label runs cleanup code for parameters, if
98 such code must be run. Following this code is the logical return label. */
100 extern rtx cleanup_label;
102 /* Label that will go on function epilogue.
103 Jumping to this label serves as a "return" instruction
104 on machines which require execution of the epilogue on all returns. */
106 extern rtx return_label;
108 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
109 So we can mark them all live at the end of the function, if nonopt. */
110 extern rtx save_expr_regs;
112 /* Offset to end of allocated area of stack frame.
113 If stack grows down, this is the address of the last stack slot allocated.
114 If stack grows up, this is the address for the next slot. */
115 extern int frame_offset;
117 /* Label to jump back to for tail recursion, or 0 if we have
118 not yet needed one for this function. */
119 extern rtx tail_recursion_label;
121 /* Place after which to insert the tail_recursion_label if we need one. */
122 extern rtx tail_recursion_reentry;
124 /* Location at which to save the argument pointer if it will need to be
125 referenced. There are two cases where this is done: if nonlocal gotos
126 exist, or if vars whose is an offset from the argument pointer will be
127 needed by inner routines. */
129 extern rtx arg_pointer_save_area;
131 /* Chain of all RTL_EXPRs that have insns in them. */
132 extern tree rtl_expr_chain;
134 #if 0 /* Turned off because 0 seems to work just as well. */
135 /* Cleanup lists are required for binding levels regardless of whether
136 that binding level has cleanups or not. This node serves as the
137 cleanup list whenever an empty list is required. */
138 static tree empty_cleanup_list;
141 extern void (*interim_eh_hook) PROTO((tree));
143 /* Functions and data structures for expanding case statements. */
145 /* Case label structure, used to hold info on labels within case
146 statements. We handle "range" labels; for a single-value label
147 as in C, the high and low limits are the same.
149 A chain of case nodes is initially maintained via the RIGHT fields
150 in the nodes. Nodes with higher case values are later in the list.
152 Switch statements can be output in one of two forms. A branch table
153 is used if there are more than a few labels and the labels are dense
154 within the range between the smallest and largest case value. If a
155 branch table is used, no further manipulations are done with the case
158 The alternative to the use of a branch table is to generate a series
159 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
160 and PARENT fields to hold a binary tree. Initially the tree is
161 totally unbalanced, with everything on the right. We balance the tree
162 with nodes on the left having lower case values than the parent
163 and nodes on the right having higher values. We then output the tree
168 struct case_node *left; /* Left son in binary tree */
169 struct case_node *right; /* Right son in binary tree; also node chain */
170 struct case_node *parent; /* Parent of node in binary tree */
171 tree low; /* Lowest index value for this label */
172 tree high; /* Highest index value for this label */
173 tree code_label; /* Label to jump to when node matches */
176 typedef struct case_node case_node;
177 typedef struct case_node *case_node_ptr;
179 /* These are used by estimate_case_costs and balance_case_nodes. */
181 /* This must be a signed type, and non-ANSI compilers lack signed char. */
182 static short *cost_table;
183 static int use_cost_table;
185 /* Stack of control and binding constructs we are currently inside.
187 These constructs begin when you call `expand_start_WHATEVER'
188 and end when you call `expand_end_WHATEVER'. This stack records
189 info about how the construct began that tells the end-function
190 what to do. It also may provide information about the construct
191 to alter the behavior of other constructs within the body.
192 For example, they may affect the behavior of C `break' and `continue'.
194 Each construct gets one `struct nesting' object.
195 All of these objects are chained through the `all' field.
196 `nesting_stack' points to the first object (innermost construct).
197 The position of an entry on `nesting_stack' is in its `depth' field.
199 Each type of construct has its own individual stack.
200 For example, loops have `loop_stack'. Each object points to the
201 next object of the same type through the `next' field.
203 Some constructs are visible to `break' exit-statements and others
204 are not. Which constructs are visible depends on the language.
205 Therefore, the data structure allows each construct to be visible
206 or not, according to the args given when the construct is started.
207 The construct is visible if the `exit_label' field is non-null.
208 In that case, the value should be a CODE_LABEL rtx. */
213 struct nesting *next;
218 /* For conds (if-then and if-then-else statements). */
221 /* Label for the end of the if construct.
222 There is none if EXITFLAG was not set
223 and no `else' has been seen yet. */
225 /* Label for the end of this alternative.
226 This may be the end of the if or the next else/elseif. */
232 /* Label at the top of the loop; place to loop back to. */
234 /* Label at the end of the whole construct. */
236 /* Label before a jump that branches to the end of the whole
237 construct. This is where destructors go if any. */
239 /* Label for `continue' statement to jump to;
240 this is in front of the stepper of the loop. */
243 /* For variable binding contours. */
246 /* Sequence number of this binding contour within the function,
247 in order of entry. */
248 int block_start_count;
249 /* Nonzero => value to restore stack to on exit. Complemented by
250 bc_stack_level (see below) when generating bytecodes. */
252 /* The NOTE that starts this contour.
253 Used by expand_goto to check whether the destination
254 is within each contour or not. */
256 /* Innermost containing binding contour that has a stack level. */
257 struct nesting *innermost_stack_block;
258 /* List of cleanups to be run on exit from this contour.
259 This is a list of expressions to be evaluated.
260 The TREE_PURPOSE of each link is the ..._DECL node
261 which the cleanup pertains to. */
263 /* List of cleanup-lists of blocks containing this block,
264 as they were at the locus where this block appears.
265 There is an element for each containing block,
266 ordered innermost containing block first.
267 The tail of this list can be 0 (was empty_cleanup_list),
268 if all remaining elements would be empty lists.
269 The element's TREE_VALUE is the cleanup-list of that block,
270 which may be null. */
272 /* Chain of labels defined inside this binding contour.
273 For contours that have stack levels or cleanups. */
274 struct label_chain *label_chain;
275 /* Number of function calls seen, as of start of this block. */
276 int function_call_count;
277 /* Bytecode specific: stack level to restore stack to on exit. */
280 /* For switch (C) or case (Pascal) statements,
281 and also for dummies (see `expand_start_case_dummy'). */
284 /* The insn after which the case dispatch should finally
285 be emitted. Zero for a dummy. */
287 /* For bytecodes, the case table is in-lined right in the code.
288 A label is needed for skipping over this block. It is only
289 used when generating bytecodes. */
291 /* A list of case labels, kept in ascending order by value
292 as the list is built.
293 During expand_end_case, this list may be rearranged into a
294 nearly balanced binary tree. */
295 struct case_node *case_list;
296 /* Label to jump to if no case matches. */
298 /* The expression to be dispatched on. */
300 /* Type that INDEX_EXPR should be converted to. */
302 /* Number of range exprs in case statement. */
304 /* Name of this kind of statement, for warnings. */
306 /* Nonzero if a case label has been seen in this case stmt. */
312 /* Chain of all pending binding contours. */
313 struct nesting *block_stack;
315 /* If any new stacks are added here, add them to POPSTACKS too. */
317 /* Chain of all pending binding contours that restore stack levels
319 struct nesting *stack_block_stack;
321 /* Chain of all pending conditional statements. */
322 struct nesting *cond_stack;
324 /* Chain of all pending loops. */
325 struct nesting *loop_stack;
327 /* Chain of all pending case or switch statements. */
328 struct nesting *case_stack;
330 /* Separate chain including all of the above,
331 chained through the `all' field. */
332 struct nesting *nesting_stack;
334 /* Number of entries on nesting_stack now. */
337 /* Allocate and return a new `struct nesting'. */
339 #define ALLOC_NESTING() \
340 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
342 /* Pop the nesting stack element by element until we pop off
343 the element which is at the top of STACK.
344 Update all the other stacks, popping off elements from them
345 as we pop them from nesting_stack. */
347 #define POPSTACK(STACK) \
348 do { struct nesting *target = STACK; \
349 struct nesting *this; \
350 do { this = nesting_stack; \
351 if (loop_stack == this) \
352 loop_stack = loop_stack->next; \
353 if (cond_stack == this) \
354 cond_stack = cond_stack->next; \
355 if (block_stack == this) \
356 block_stack = block_stack->next; \
357 if (stack_block_stack == this) \
358 stack_block_stack = stack_block_stack->next; \
359 if (case_stack == this) \
360 case_stack = case_stack->next; \
361 nesting_depth = nesting_stack->depth - 1; \
362 nesting_stack = this->all; \
363 obstack_free (&stmt_obstack, this); } \
364 while (this != target); } while (0)
366 /* In some cases it is impossible to generate code for a forward goto
367 until the label definition is seen. This happens when it may be necessary
368 for the goto to reset the stack pointer: we don't yet know how to do that.
369 So expand_goto puts an entry on this fixup list.
370 Each time a binding contour that resets the stack is exited,
372 If the target label has now been defined, we can insert the proper code. */
376 /* Points to following fixup. */
377 struct goto_fixup *next;
378 /* Points to the insn before the jump insn.
379 If more code must be inserted, it goes after this insn. */
381 /* The LABEL_DECL that this jump is jumping to, or 0
382 for break, continue or return. */
384 /* The BLOCK for the place where this goto was found. */
386 /* The CODE_LABEL rtx that this is jumping to. */
388 /* Number of binding contours started in current function
389 before the label reference. */
390 int block_start_count;
391 /* The outermost stack level that should be restored for this jump.
392 Each time a binding contour that resets the stack is exited,
393 if the target label is *not* yet defined, this slot is updated. */
395 /* List of lists of cleanup expressions to be run by this goto.
396 There is one element for each block that this goto is within.
397 The tail of this list can be 0 (was empty_cleanup_list),
398 if all remaining elements would be empty.
399 The TREE_VALUE contains the cleanup list of that block as of the
400 time this goto was seen.
401 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
402 tree cleanup_list_list;
404 /* Bytecode specific members follow */
406 /* The label that this jump is jumping to, or 0 for break, continue
408 struct bc_label *bc_target;
410 /* The label we use for the fixup patch */
411 struct bc_label *label;
413 /* True (non-0) if fixup has been handled */
416 /* Like stack_level above, except refers to the interpreter stack */
420 static struct goto_fixup *goto_fixup_chain;
422 /* Within any binding contour that must restore a stack level,
423 all labels are recorded with a chain of these structures. */
427 /* Points to following fixup. */
428 struct label_chain *next;
431 static void expand_goto_internal PROTO((tree, rtx, rtx));
432 static void bc_expand_goto_internal PROTO((enum bytecode_opcode,
433 struct bc_label *, tree));
434 static int expand_fixup PROTO((tree, rtx, rtx));
435 static void bc_expand_fixup PROTO((enum bytecode_opcode,
436 struct bc_label *, int));
437 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
439 static void bc_fixup_gotos PROTO((struct nesting *, int, tree,
441 static void bc_expand_start_cond PROTO((tree, int));
442 static void bc_expand_end_cond PROTO((void));
443 static void bc_expand_start_else PROTO((void));
444 static void bc_expand_end_loop PROTO((void));
445 static void bc_expand_end_bindings PROTO((tree, int, int));
446 static void bc_expand_decl PROTO((tree, tree));
447 static void bc_expand_variable_local_init PROTO((tree));
448 static void bc_expand_decl_init PROTO((tree));
449 static void expand_null_return_1 PROTO((rtx, int));
450 static void expand_value_return PROTO((rtx));
451 static int tail_recursion_args PROTO((tree, tree));
452 static void expand_cleanups PROTO((tree, tree, int, int));
453 static void bc_expand_start_case PROTO((struct nesting *, tree,
455 static int bc_pushcase PROTO((tree, tree));
456 static void bc_check_for_full_enumeration_handling PROTO((tree));
457 static void bc_expand_end_case PROTO((tree));
458 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
459 static int estimate_case_costs PROTO((case_node_ptr));
460 static void group_case_nodes PROTO((case_node_ptr));
461 static void balance_case_nodes PROTO((case_node_ptr *,
463 static int node_has_low_bound PROTO((case_node_ptr, tree));
464 static int node_has_high_bound PROTO((case_node_ptr, tree));
465 static int node_is_bounded PROTO((case_node_ptr, tree));
466 static void emit_jump_if_reachable PROTO((rtx));
467 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
469 int bc_expand_exit_loop_if_false ();
470 void bc_expand_start_cond ();
471 void bc_expand_end_cond ();
472 void bc_expand_start_else ();
473 void bc_expand_end_bindings ();
474 void bc_expand_start_case ();
475 void bc_check_for_full_enumeration_handling ();
476 void bc_expand_end_case ();
477 void bc_expand_decl ();
479 extern rtx bc_allocate_local ();
480 extern rtx bc_allocate_variable_array ();
485 gcc_obstack_init (&stmt_obstack);
487 empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE);
492 init_stmt_for_function ()
494 /* We are not currently within any block, conditional, loop or case. */
496 stack_block_stack = 0;
503 block_start_count = 0;
505 /* No gotos have been expanded yet. */
506 goto_fixup_chain = 0;
508 /* We are not processing a ({...}) grouping. */
509 expr_stmts_for_value = 0;
517 p->block_stack = block_stack;
518 p->stack_block_stack = stack_block_stack;
519 p->cond_stack = cond_stack;
520 p->loop_stack = loop_stack;
521 p->case_stack = case_stack;
522 p->nesting_stack = nesting_stack;
523 p->nesting_depth = nesting_depth;
524 p->block_start_count = block_start_count;
525 p->last_expr_type = last_expr_type;
526 p->last_expr_value = last_expr_value;
527 p->expr_stmts_for_value = expr_stmts_for_value;
528 p->emit_filename = emit_filename;
529 p->emit_lineno = emit_lineno;
530 p->goto_fixup_chain = goto_fixup_chain;
534 restore_stmt_status (p)
537 block_stack = p->block_stack;
538 stack_block_stack = p->stack_block_stack;
539 cond_stack = p->cond_stack;
540 loop_stack = p->loop_stack;
541 case_stack = p->case_stack;
542 nesting_stack = p->nesting_stack;
543 nesting_depth = p->nesting_depth;
544 block_start_count = p->block_start_count;
545 last_expr_type = p->last_expr_type;
546 last_expr_value = p->last_expr_value;
547 expr_stmts_for_value = p->expr_stmts_for_value;
548 emit_filename = p->emit_filename;
549 emit_lineno = p->emit_lineno;
550 goto_fixup_chain = p->goto_fixup_chain;
553 /* Emit a no-op instruction. */
560 if (!output_bytecode)
562 last_insn = get_last_insn ();
564 && (GET_CODE (last_insn) == CODE_LABEL
565 || prev_real_insn (last_insn) == 0))
566 emit_insn (gen_nop ());
570 /* Return the rtx-label that corresponds to a LABEL_DECL,
571 creating it if necessary. */
577 if (TREE_CODE (label) != LABEL_DECL)
580 if (DECL_RTL (label))
581 return DECL_RTL (label);
583 return DECL_RTL (label) = gen_label_rtx ();
586 /* Add an unconditional jump to LABEL as the next sequential instruction. */
592 do_pending_stack_adjust ();
593 emit_jump_insn (gen_jump (label));
597 /* Emit code to jump to the address
598 specified by the pointer expression EXP. */
601 expand_computed_goto (exp)
606 bc_expand_expr (exp);
607 bc_emit_instruction (jumpP);
611 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
613 #ifdef POINTERS_EXTEND_UNSIGNED
614 x = convert_memory_address (Pmode, x);
618 do_pending_stack_adjust ();
619 emit_indirect_jump (x);
623 /* Handle goto statements and the labels that they can go to. */
625 /* Specify the location in the RTL code of a label LABEL,
626 which is a LABEL_DECL tree node.
628 This is used for the kind of label that the user can jump to with a
629 goto statement, and for alternatives of a switch or case statement.
630 RTL labels generated for loops and conditionals don't go through here;
631 they are generated directly at the RTL level, by other functions below.
633 Note that this has nothing to do with defining label *names*.
634 Languages vary in how they do that and what that even means. */
640 struct label_chain *p;
644 if (! DECL_RTL (label))
645 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
646 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
647 error ("multiply defined label");
651 do_pending_stack_adjust ();
652 emit_label (label_rtx (label));
653 if (DECL_NAME (label))
654 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
656 if (stack_block_stack != 0)
658 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
659 p->next = stack_block_stack->data.block.label_chain;
660 stack_block_stack->data.block.label_chain = p;
665 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
666 from nested functions. */
669 declare_nonlocal_label (label)
672 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
673 LABEL_PRESERVE_P (label_rtx (label)) = 1;
674 if (nonlocal_goto_handler_slot == 0)
676 nonlocal_goto_handler_slot
677 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
678 emit_stack_save (SAVE_NONLOCAL,
679 &nonlocal_goto_stack_level,
680 PREV_INSN (tail_recursion_reentry));
684 /* Generate RTL code for a `goto' statement with target label LABEL.
685 LABEL should be a LABEL_DECL tree node that was or will later be
686 defined with `expand_label'. */
696 expand_goto_internal (label, label_rtx (label), NULL_RTX);
700 /* Check for a nonlocal goto to a containing function. */
701 context = decl_function_context (label);
702 if (context != 0 && context != current_function_decl)
704 struct function *p = find_function_data (context);
705 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
708 p->has_nonlocal_label = 1;
709 current_function_has_nonlocal_goto = 1;
710 LABEL_REF_NONLOCAL_P (label_ref) = 1;
712 /* Copy the rtl for the slots so that they won't be shared in
713 case the virtual stack vars register gets instantiated differently
714 in the parent than in the child. */
716 #if HAVE_nonlocal_goto
717 if (HAVE_nonlocal_goto)
718 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
719 copy_rtx (p->nonlocal_goto_handler_slot),
720 copy_rtx (p->nonlocal_goto_stack_level),
727 /* Restore frame pointer for containing function.
728 This sets the actual hard register used for the frame pointer
729 to the location of the function's incoming static chain info.
730 The non-local goto handler will then adjust it to contain the
731 proper value and reload the argument pointer, if needed. */
732 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
734 /* We have now loaded the frame pointer hardware register with
735 the address of that corresponds to the start of the virtual
736 stack vars. So replace virtual_stack_vars_rtx in all
737 addresses we use with stack_pointer_rtx. */
739 /* Get addr of containing function's current nonlocal goto handler,
740 which will do any cleanups and then jump to the label. */
741 addr = copy_rtx (p->nonlocal_goto_handler_slot);
742 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
743 hard_frame_pointer_rtx));
745 /* Restore the stack pointer. Note this uses fp just restored. */
746 addr = p->nonlocal_goto_stack_level;
748 addr = replace_rtx (copy_rtx (addr),
749 virtual_stack_vars_rtx,
750 hard_frame_pointer_rtx);
752 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
754 /* Put in the static chain register the nonlocal label address. */
755 emit_move_insn (static_chain_rtx, label_ref);
756 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
758 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
759 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
760 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
761 emit_indirect_jump (temp);
765 expand_goto_internal (label, label_rtx (label), NULL_RTX);
768 /* Generate RTL code for a `goto' statement with target label BODY.
769 LABEL should be a LABEL_REF.
770 LAST_INSN, if non-0, is the rtx we should consider as the last
771 insn emitted (for the purposes of cleaning up a return). */
774 expand_goto_internal (body, label, last_insn)
779 struct nesting *block;
782 /* NOTICE! If a bytecode instruction other than `jump' is needed,
783 then the caller has to call bc_expand_goto_internal()
784 directly. This is rather an exceptional case, and there aren't
785 that many places where this is necessary. */
788 expand_goto_internal (body, label, last_insn);
792 if (GET_CODE (label) != CODE_LABEL)
795 /* If label has already been defined, we can tell now
796 whether and how we must alter the stack level. */
798 if (PREV_INSN (label) != 0)
800 /* Find the innermost pending block that contains the label.
801 (Check containment by comparing insn-uids.)
802 Then restore the outermost stack level within that block,
803 and do cleanups of all blocks contained in it. */
804 for (block = block_stack; block; block = block->next)
806 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
808 if (block->data.block.stack_level != 0)
809 stack_level = block->data.block.stack_level;
810 /* Execute the cleanups for blocks we are exiting. */
811 if (block->data.block.cleanups != 0)
813 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
814 do_pending_stack_adjust ();
820 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
821 the stack pointer. This one should be deleted as dead by flow. */
822 clear_pending_stack_adjust ();
823 do_pending_stack_adjust ();
824 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
827 if (body != 0 && DECL_TOO_LATE (body))
828 error ("jump to `%s' invalidly jumps into binding contour",
829 IDENTIFIER_POINTER (DECL_NAME (body)));
831 /* Label not yet defined: may need to put this goto
832 on the fixup list. */
833 else if (! expand_fixup (body, label, last_insn))
835 /* No fixup needed. Record that the label is the target
836 of at least one goto that has no fixup. */
838 TREE_ADDRESSABLE (body) = 1;
844 /* Generate a jump with OPCODE to the given bytecode LABEL which is
845 found within BODY. */
848 bc_expand_goto_internal (opcode, label, body)
849 enum bytecode_opcode opcode;
850 struct bc_label *label;
853 struct nesting *block;
854 int stack_level = -1;
856 /* If the label is defined, adjust the stack as necessary.
857 If it's not defined, we have to push the reference on the
863 /* Find the innermost pending block that contains the label.
864 (Check containment by comparing bytecode uids.) Then restore the
865 outermost stack level within that block. */
867 for (block = block_stack; block; block = block->next)
869 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
871 if (block->data.block.bc_stack_level)
872 stack_level = block->data.block.bc_stack_level;
874 /* Execute the cleanups for blocks we are exiting. */
875 if (block->data.block.cleanups != 0)
877 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
878 do_pending_stack_adjust ();
882 /* Restore the stack level. If we need to adjust the stack, we
883 must do so after the jump, since the jump may depend on
884 what's on the stack. Thus, any stack-modifying conditional
885 jumps (these are the only ones that rely on what's on the
886 stack) go into the fixup list. */
889 && stack_depth != stack_level
892 bc_expand_fixup (opcode, label, stack_level);
895 if (stack_level >= 0)
896 bc_adjust_stack (stack_depth - stack_level);
898 if (body && DECL_BIT_FIELD (body))
899 error ("jump to `%s' invalidly jumps into binding contour",
900 IDENTIFIER_POINTER (DECL_NAME (body)));
902 /* Emit immediate jump */
903 bc_emit_bytecode (opcode);
904 bc_emit_bytecode_labelref (label);
906 #ifdef DEBUG_PRINT_CODE
907 fputc ('\n', stderr);
912 /* Put goto in the fixup list */
913 bc_expand_fixup (opcode, label, stack_level);
916 /* Generate if necessary a fixup for a goto
917 whose target label in tree structure (if any) is TREE_LABEL
918 and whose target in rtl is RTL_LABEL.
920 If LAST_INSN is nonzero, we pretend that the jump appears
921 after insn LAST_INSN instead of at the current point in the insn stream.
923 The fixup will be used later to insert insns just before the goto.
924 Those insns will restore the stack level as appropriate for the
925 target label, and will (in the case of C++) also invoke any object
926 destructors which have to be invoked when we exit the scopes which
927 are exited by the goto.
929 Value is nonzero if a fixup is made. */
932 expand_fixup (tree_label, rtl_label, last_insn)
937 struct nesting *block, *end_block;
939 /* See if we can recognize which block the label will be output in.
940 This is possible in some very common cases.
941 If we succeed, set END_BLOCK to that block.
942 Otherwise, set it to 0. */
945 && (rtl_label == cond_stack->data.cond.endif_label
946 || rtl_label == cond_stack->data.cond.next_label))
947 end_block = cond_stack;
948 /* If we are in a loop, recognize certain labels which
949 are likely targets. This reduces the number of fixups
950 we need to create. */
952 && (rtl_label == loop_stack->data.loop.start_label
953 || rtl_label == loop_stack->data.loop.end_label
954 || rtl_label == loop_stack->data.loop.continue_label))
955 end_block = loop_stack;
959 /* Now set END_BLOCK to the binding level to which we will return. */
963 struct nesting *next_block = end_block->all;
966 /* First see if the END_BLOCK is inside the innermost binding level.
967 If so, then no cleanups or stack levels are relevant. */
968 while (next_block && next_block != block)
969 next_block = next_block->all;
974 /* Otherwise, set END_BLOCK to the innermost binding level
975 which is outside the relevant control-structure nesting. */
976 next_block = block_stack->next;
977 for (block = block_stack; block != end_block; block = block->all)
978 if (block == next_block)
979 next_block = next_block->next;
980 end_block = next_block;
983 /* Does any containing block have a stack level or cleanups?
984 If not, no fixup is needed, and that is the normal case
985 (the only case, for standard C). */
986 for (block = block_stack; block != end_block; block = block->next)
987 if (block->data.block.stack_level != 0
988 || block->data.block.cleanups != 0)
991 if (block != end_block)
993 /* Ok, a fixup is needed. Add a fixup to the list of such. */
994 struct goto_fixup *fixup
995 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
996 /* In case an old stack level is restored, make sure that comes
997 after any pending stack adjust. */
998 /* ?? If the fixup isn't to come at the present position,
999 doing the stack adjust here isn't useful. Doing it with our
1000 settings at that location isn't useful either. Let's hope
1003 do_pending_stack_adjust ();
1004 fixup->target = tree_label;
1005 fixup->target_rtl = rtl_label;
1007 /* Create a BLOCK node and a corresponding matched set of
1008 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1009 this point. The notes will encapsulate any and all fixup
1010 code which we might later insert at this point in the insn
1011 stream. Also, the BLOCK node will be the parent (i.e. the
1012 `SUPERBLOCK') of any other BLOCK nodes which we might create
1013 later on when we are expanding the fixup code. */
1016 register rtx original_before_jump
1017 = last_insn ? last_insn : get_last_insn ();
1021 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1022 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1023 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1025 emit_insns_after (fixup->before_jump, original_before_jump);
1028 fixup->block_start_count = block_start_count;
1029 fixup->stack_level = 0;
1030 fixup->cleanup_list_list
1031 = (((block->data.block.outer_cleanups
1033 && block->data.block.outer_cleanups != empty_cleanup_list
1036 || block->data.block.cleanups)
1037 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1038 block->data.block.outer_cleanups)
1040 fixup->next = goto_fixup_chain;
1041 goto_fixup_chain = fixup;
1048 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1049 Make the fixup restore the stack level to STACK_LEVEL. */
1052 bc_expand_fixup (opcode, label, stack_level)
1053 enum bytecode_opcode opcode;
1054 struct bc_label *label;
1057 struct goto_fixup *fixup
1058 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1060 fixup->label = bc_get_bytecode_label ();
1061 fixup->bc_target = label;
1062 fixup->bc_stack_level = stack_level;
1063 fixup->bc_handled = FALSE;
1065 fixup->next = goto_fixup_chain;
1066 goto_fixup_chain = fixup;
1068 /* Insert a jump to the fixup code */
1069 bc_emit_bytecode (opcode);
1070 bc_emit_bytecode_labelref (fixup->label);
1072 #ifdef DEBUG_PRINT_CODE
1073 fputc ('\n', stderr);
1077 /* Expand any needed fixups in the outputmost binding level of the
1078 function. FIRST_INSN is the first insn in the function. */
1081 expand_fixups (first_insn)
1084 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1087 /* When exiting a binding contour, process all pending gotos requiring fixups.
1088 THISBLOCK is the structure that describes the block being exited.
1089 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1090 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1091 FIRST_INSN is the insn that began this contour.
1093 Gotos that jump out of this contour must restore the
1094 stack level and do the cleanups before actually jumping.
1096 DONT_JUMP_IN nonzero means report error there is a jump into this
1097 contour from before the beginning of the contour.
1098 This is also done if STACK_LEVEL is nonzero. */
1101 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1102 struct nesting *thisblock;
1108 register struct goto_fixup *f, *prev;
1110 if (output_bytecode)
1112 /* ??? The second arg is the bc stack level, which is not the same
1113 as STACK_LEVEL. I have no idea what should go here, so I'll
1115 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1119 /* F is the fixup we are considering; PREV is the previous one. */
1120 /* We run this loop in two passes so that cleanups of exited blocks
1121 are run first, and blocks that are exited are marked so
1124 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1126 /* Test for a fixup that is inactive because it is already handled. */
1127 if (f->before_jump == 0)
1129 /* Delete inactive fixup from the chain, if that is easy to do. */
1131 prev->next = f->next;
1133 /* Has this fixup's target label been defined?
1134 If so, we can finalize it. */
1135 else if (PREV_INSN (f->target_rtl) != 0)
1137 register rtx cleanup_insns;
1139 /* Get the first non-label after the label
1140 this goto jumps to. If that's before this scope begins,
1141 we don't have a jump into the scope. */
1142 rtx after_label = f->target_rtl;
1143 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1144 after_label = NEXT_INSN (after_label);
1146 /* If this fixup jumped into this contour from before the beginning
1147 of this contour, report an error. */
1148 /* ??? Bug: this does not detect jumping in through intermediate
1149 blocks that have stack levels or cleanups.
1150 It detects only a problem with the innermost block
1151 around the label. */
1153 && (dont_jump_in || stack_level || cleanup_list)
1154 /* If AFTER_LABEL is 0, it means the jump goes to the end
1155 of the rtl, which means it jumps into this scope. */
1156 && (after_label == 0
1157 || INSN_UID (first_insn) < INSN_UID (after_label))
1158 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1159 && ! DECL_REGISTER (f->target))
1161 error_with_decl (f->target,
1162 "label `%s' used before containing binding contour");
1163 /* Prevent multiple errors for one label. */
1164 DECL_REGISTER (f->target) = 1;
1167 /* We will expand the cleanups into a sequence of their own and
1168 then later on we will attach this new sequence to the insn
1169 stream just ahead of the actual jump insn. */
1173 /* Temporarily restore the lexical context where we will
1174 logically be inserting the fixup code. We do this for the
1175 sake of getting the debugging information right. */
1178 set_block (f->context);
1180 /* Expand the cleanups for blocks this jump exits. */
1181 if (f->cleanup_list_list)
1184 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1185 /* Marked elements correspond to blocks that have been closed.
1186 Do their cleanups. */
1187 if (TREE_ADDRESSABLE (lists)
1188 && TREE_VALUE (lists) != 0)
1190 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1191 /* Pop any pushes done in the cleanups,
1192 in case function is about to return. */
1193 do_pending_stack_adjust ();
1197 /* Restore stack level for the biggest contour that this
1198 jump jumps out of. */
1200 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1202 /* Finish up the sequence containing the insns which implement the
1203 necessary cleanups, and then attach that whole sequence to the
1204 insn stream just ahead of the actual jump insn. Attaching it
1205 at that point insures that any cleanups which are in fact
1206 implicit C++ object destructions (which must be executed upon
1207 leaving the block) appear (to the debugger) to be taking place
1208 in an area of the generated code where the object(s) being
1209 destructed are still "in scope". */
1211 cleanup_insns = get_insns ();
1215 emit_insns_after (cleanup_insns, f->before_jump);
1222 /* For any still-undefined labels, do the cleanups for this block now.
1223 We must do this now since items in the cleanup list may go out
1224 of scope when the block ends. */
1225 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1226 if (f->before_jump != 0
1227 && PREV_INSN (f->target_rtl) == 0
1228 /* Label has still not appeared. If we are exiting a block with
1229 a stack level to restore, that started before the fixup,
1230 mark this stack level as needing restoration
1231 when the fixup is later finalized. */
1233 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1234 means the label is undefined. That's erroneous, but possible. */
1235 && (thisblock->data.block.block_start_count
1236 <= f->block_start_count))
1238 tree lists = f->cleanup_list_list;
1241 for (; lists; lists = TREE_CHAIN (lists))
1242 /* If the following elt. corresponds to our containing block
1243 then the elt. must be for this block. */
1244 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1248 set_block (f->context);
1249 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1250 do_pending_stack_adjust ();
1251 cleanup_insns = get_insns ();
1255 = emit_insns_after (cleanup_insns, f->before_jump);
1257 TREE_VALUE (lists) = 0;
1261 f->stack_level = stack_level;
1266 /* When exiting a binding contour, process all pending gotos requiring fixups.
1267 Note: STACK_DEPTH is not altered.
1269 The arguments are currently not used in the bytecode compiler, but we may
1270 need them one day for languages other than C.
1272 THISBLOCK is the structure that describes the block being exited.
1273 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1274 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1275 FIRST_INSN is the insn that began this contour.
1277 Gotos that jump out of this contour must restore the
1278 stack level and do the cleanups before actually jumping.
1280 DONT_JUMP_IN nonzero means report error there is a jump into this
1281 contour from before the beginning of the contour.
1282 This is also done if STACK_LEVEL is nonzero. */
1285 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1286 struct nesting *thisblock;
1292 register struct goto_fixup *f, *prev;
1293 int saved_stack_depth;
1295 /* F is the fixup we are considering; PREV is the previous one. */
1297 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1299 /* Test for a fixup that is inactive because it is already handled. */
1300 if (f->before_jump == 0)
1302 /* Delete inactive fixup from the chain, if that is easy to do. */
1304 prev->next = f->next;
1307 /* Emit code to restore the stack and continue */
1308 bc_emit_bytecode_labeldef (f->label);
1310 /* Save stack_depth across call, since bc_adjust_stack () will alter
1311 the perceived stack depth via the instructions generated. */
1313 if (f->bc_stack_level >= 0)
1315 saved_stack_depth = stack_depth;
1316 bc_adjust_stack (stack_depth - f->bc_stack_level);
1317 stack_depth = saved_stack_depth;
1320 bc_emit_bytecode (jump);
1321 bc_emit_bytecode_labelref (f->bc_target);
1323 #ifdef DEBUG_PRINT_CODE
1324 fputc ('\n', stderr);
1328 goto_fixup_chain = NULL;
1331 /* Generate RTL for an asm statement (explicit assembler code).
1332 BODY is a STRING_CST node containing the assembler code text,
1333 or an ADDR_EXPR containing a STRING_CST. */
1339 if (output_bytecode)
1341 error ("`asm' is invalid when generating bytecode");
1345 if (TREE_CODE (body) == ADDR_EXPR)
1346 body = TREE_OPERAND (body, 0);
1348 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1349 TREE_STRING_POINTER (body)));
1353 /* Generate RTL for an asm statement with arguments.
1354 STRING is the instruction template.
1355 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1356 Each output or input has an expression in the TREE_VALUE and
1357 a constraint-string in the TREE_PURPOSE.
1358 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1359 that is clobbered by this insn.
1361 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1362 Some elements of OUTPUTS may be replaced with trees representing temporary
1363 values. The caller should copy those temporary values to the originally
1366 VOL nonzero means the insn is volatile; don't optimize it. */
1369 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1370 tree string, outputs, inputs, clobbers;
1375 rtvec argvec, constraints;
1377 int ninputs = list_length (inputs);
1378 int noutputs = list_length (outputs);
1382 /* Vector of RTX's of evaluated output operands. */
1383 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1384 /* The insn we have emitted. */
1387 if (output_bytecode)
1389 error ("`asm' is invalid when generating bytecode");
1393 /* Count the number of meaningful clobbered registers, ignoring what
1394 we would ignore later. */
1396 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1398 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1399 i = decode_reg_name (regname);
1400 if (i >= 0 || i == -4)
1403 error ("unknown register name `%s' in `asm'", regname);
1408 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1410 tree val = TREE_VALUE (tail);
1411 tree type = TREE_TYPE (val);
1414 int found_equal = 0;
1417 /* If there's an erroneous arg, emit no insn. */
1418 if (TREE_TYPE (val) == error_mark_node)
1421 /* Make sure constraint has `=' and does not have `+'. Also, see
1422 if it allows any register. Be liberal on the latter test, since
1423 the worst that happens if we get it wrong is we issue an error
1426 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1427 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1430 error ("output operand constraint contains `+'");
1437 case '?': case '!': case '*': case '%': case '&':
1438 case '0': case '1': case '2': case '3': case '4':
1439 case 'V': case 'm': case 'o': case '<': case '>':
1440 case 'E': case 'F': case 'G': case 'H': case 'X':
1441 case 's': case 'i': case 'n':
1442 case 'I': case 'J': case 'K': case 'L': case 'M':
1443 case 'N': case 'O': case 'P': case ',':
1444 #ifdef EXTRA_CONSTRAINT
1445 case 'Q': case 'R': case 'S': case 'T': case 'U':
1449 case 'p': case 'g': case 'r':
1457 error ("output operand constraint lacks `='");
1461 /* If an output operand is not a decl or indirect ref and our constraint
1462 allows a register, make a temporary to act as an intermediate.
1463 Make the asm insn write into that, then our caller will copy it to
1464 the real output operand. Likewise for promoted variables. */
1466 if (TREE_CODE (val) == INDIRECT_REF
1467 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1468 && ! (GET_CODE (DECL_RTL (val)) == REG
1469 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1473 mark_addressable (TREE_VALUE (tail));
1476 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1478 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1479 error ("output number %d not directly addressable", i);
1483 if (TYPE_MODE (type) == BLKmode)
1485 output_rtx[i] = assign_stack_temp (BLKmode,
1486 int_size_in_bytes (type), 0);
1487 MEM_IN_STRUCT_P (output_rtx[i]) = AGGREGATE_TYPE_P (type);
1490 output_rtx[i] = gen_reg_rtx (TYPE_MODE (type));
1492 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1496 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1498 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1502 /* Make vectors for the expression-rtx and constraint strings. */
1504 argvec = rtvec_alloc (ninputs);
1505 constraints = rtvec_alloc (ninputs);
1507 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1508 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1510 MEM_VOLATILE_P (body) = vol;
1512 /* Eval the inputs and put them into ARGVEC.
1513 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1516 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1520 /* If there's an erroneous arg, emit no insn,
1521 because the ASM_INPUT would get VOIDmode
1522 and that could cause a crash in reload. */
1523 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1525 if (TREE_PURPOSE (tail) == NULL_TREE)
1527 error ("hard register `%s' listed as input operand to `asm'",
1528 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1532 /* Make sure constraint has neither `=' nor `+'. */
1534 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1535 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '='
1536 || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1538 error ("input operand constraint contains `%c'",
1539 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1543 XVECEXP (body, 3, i) /* argvec */
1544 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1545 if (CONSTANT_P (XVECEXP (body, 3, i))
1546 && ! general_operand (XVECEXP (body, 3, i),
1547 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1548 XVECEXP (body, 3, i)
1549 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1550 XVECEXP (body, 3, i));
1551 XVECEXP (body, 4, i) /* constraints */
1552 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1553 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1557 /* Protect all the operands from the queue,
1558 now that they have all been evaluated. */
1560 for (i = 0; i < ninputs; i++)
1561 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1563 for (i = 0; i < noutputs; i++)
1564 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1566 /* Now, for each output, construct an rtx
1567 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1568 ARGVEC CONSTRAINTS))
1569 If there is more than one, put them inside a PARALLEL. */
1571 if (noutputs == 1 && nclobbers == 0)
1573 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1574 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1576 else if (noutputs == 0 && nclobbers == 0)
1578 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1579 insn = emit_insn (body);
1585 if (num == 0) num = 1;
1586 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1588 /* For each output operand, store a SET. */
1590 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1592 XVECEXP (body, 0, i)
1593 = gen_rtx (SET, VOIDmode,
1595 gen_rtx (ASM_OPERANDS, VOIDmode,
1596 TREE_STRING_POINTER (string),
1597 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1598 i, argvec, constraints,
1600 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1603 /* If there are no outputs (but there are some clobbers)
1604 store the bare ASM_OPERANDS into the PARALLEL. */
1607 XVECEXP (body, 0, i++) = obody;
1609 /* Store (clobber REG) for each clobbered register specified. */
1611 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1613 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1614 int j = decode_reg_name (regname);
1618 if (j == -3) /* `cc', which is not a register */
1621 if (j == -4) /* `memory', don't cache memory across asm */
1623 XVECEXP (body, 0, i++)
1624 = gen_rtx (CLOBBER, VOIDmode,
1625 gen_rtx (MEM, BLKmode,
1626 gen_rtx (SCRATCH, VOIDmode, 0)));
1630 /* Ignore unknown register, error already signalled. */
1634 /* Use QImode since that's guaranteed to clobber just one reg. */
1635 XVECEXP (body, 0, i++)
1636 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1639 insn = emit_insn (body);
1645 /* Generate RTL to evaluate the expression EXP
1646 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1649 expand_expr_stmt (exp)
1652 if (output_bytecode)
1654 int org_stack_depth = stack_depth;
1656 bc_expand_expr (exp);
1658 /* Restore stack depth */
1659 if (stack_depth < org_stack_depth)
1662 bc_emit_instruction (drop);
1664 last_expr_type = TREE_TYPE (exp);
1668 /* If -W, warn about statements with no side effects,
1669 except for an explicit cast to void (e.g. for assert()), and
1670 except inside a ({...}) where they may be useful. */
1671 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1673 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1674 && !(TREE_CODE (exp) == CONVERT_EXPR
1675 && TREE_TYPE (exp) == void_type_node))
1676 warning_with_file_and_line (emit_filename, emit_lineno,
1677 "statement with no effect");
1678 else if (warn_unused)
1679 warn_if_unused_value (exp);
1682 /* If EXP is of function type and we are expanding statements for
1683 value, convert it to pointer-to-function. */
1684 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1685 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1687 last_expr_type = TREE_TYPE (exp);
1688 if (! flag_syntax_only)
1689 last_expr_value = expand_expr (exp,
1690 (expr_stmts_for_value
1691 ? NULL_RTX : const0_rtx),
1694 /* If all we do is reference a volatile value in memory,
1695 copy it to a register to be sure it is actually touched. */
1696 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1697 && TREE_THIS_VOLATILE (exp))
1699 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1701 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1702 copy_to_reg (last_expr_value);
1705 rtx lab = gen_label_rtx ();
1707 /* Compare the value with itself to reference it. */
1708 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1709 expand_expr (TYPE_SIZE (last_expr_type),
1710 NULL_RTX, VOIDmode, 0),
1712 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1713 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1718 /* If this expression is part of a ({...}) and is in memory, we may have
1719 to preserve temporaries. */
1720 preserve_temp_slots (last_expr_value);
1722 /* Free any temporaries used to evaluate this expression. Any temporary
1723 used as a result of this expression will already have been preserved
1730 /* Warn if EXP contains any computations whose results are not used.
1731 Return 1 if a warning is printed; 0 otherwise. */
1734 warn_if_unused_value (exp)
1737 if (TREE_USED (exp))
1740 switch (TREE_CODE (exp))
1742 case PREINCREMENT_EXPR:
1743 case POSTINCREMENT_EXPR:
1744 case PREDECREMENT_EXPR:
1745 case POSTDECREMENT_EXPR:
1750 case METHOD_CALL_EXPR:
1752 case WITH_CLEANUP_EXPR:
1754 /* We don't warn about COND_EXPR because it may be a useful
1755 construct if either arm contains a side effect. */
1760 /* For a binding, warn if no side effect within it. */
1761 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1764 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1766 case TRUTH_ORIF_EXPR:
1767 case TRUTH_ANDIF_EXPR:
1768 /* In && or ||, warn if 2nd operand has no side effect. */
1769 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1772 if (TREE_NO_UNUSED_WARNING (exp))
1774 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1776 /* Let people do `(foo (), 0)' without a warning. */
1777 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1779 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1783 case NON_LVALUE_EXPR:
1784 /* Don't warn about values cast to void. */
1785 if (TREE_TYPE (exp) == void_type_node)
1787 /* Don't warn about conversions not explicit in the user's program. */
1788 if (TREE_NO_UNUSED_WARNING (exp))
1790 /* Assignment to a cast usually results in a cast of a modify.
1791 Don't complain about that. There can be an arbitrary number of
1792 casts before the modify, so we must loop until we find the first
1793 non-cast expression and then test to see if that is a modify. */
1795 tree tem = TREE_OPERAND (exp, 0);
1797 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1798 tem = TREE_OPERAND (tem, 0);
1800 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1801 || TREE_CODE (tem) == CALL_EXPR)
1807 /* Don't warn about automatic dereferencing of references, since
1808 the user cannot control it. */
1809 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1810 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1811 /* ... fall through ... */
1814 /* Referencing a volatile value is a side effect, so don't warn. */
1815 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1816 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1817 && TREE_THIS_VOLATILE (exp))
1820 warning_with_file_and_line (emit_filename, emit_lineno,
1821 "value computed is not used");
1826 /* Clear out the memory of the last expression evaluated. */
1834 /* Begin a statement which will return a value.
1835 Return the RTL_EXPR for this statement expr.
1836 The caller must save that value and pass it to expand_end_stmt_expr. */
1839 expand_start_stmt_expr ()
1844 /* When generating bytecode just note down the stack depth */
1845 if (output_bytecode)
1846 return (build_int_2 (stack_depth, 0));
1848 /* Make the RTL_EXPR node temporary, not momentary,
1849 so that rtl_expr_chain doesn't become garbage. */
1850 momentary = suspend_momentary ();
1851 t = make_node (RTL_EXPR);
1852 resume_momentary (momentary);
1853 start_sequence_for_rtl_expr (t);
1855 expr_stmts_for_value++;
1859 /* Restore the previous state at the end of a statement that returns a value.
1860 Returns a tree node representing the statement's value and the
1861 insns to compute the value.
1863 The nodes of that expression have been freed by now, so we cannot use them.
1864 But we don't want to do that anyway; the expression has already been
1865 evaluated and now we just want to use the value. So generate a RTL_EXPR
1866 with the proper type and RTL value.
1868 If the last substatement was not an expression,
1869 return something with type `void'. */
1872 expand_end_stmt_expr (t)
1875 if (output_bytecode)
1881 /* At this point, all expressions have been evaluated in order.
1882 However, all expression values have been popped when evaluated,
1883 which means we have to recover the last expression value. This is
1884 the last value removed by means of a `drop' instruction. Instead
1885 of adding code to inhibit dropping the last expression value, it
1886 is here recovered by undoing the `drop'. Since `drop' is
1887 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1890 bc_adjust_stack (-1);
1892 if (!last_expr_type)
1893 last_expr_type = void_type_node;
1895 t = make_node (RTL_EXPR);
1896 TREE_TYPE (t) = last_expr_type;
1897 RTL_EXPR_RTL (t) = NULL;
1898 RTL_EXPR_SEQUENCE (t) = NULL;
1900 /* Don't consider deleting this expr or containing exprs at tree level. */
1901 TREE_THIS_VOLATILE (t) = 1;
1909 if (last_expr_type == 0)
1911 last_expr_type = void_type_node;
1912 last_expr_value = const0_rtx;
1914 else if (last_expr_value == 0)
1915 /* There are some cases where this can happen, such as when the
1916 statement is void type. */
1917 last_expr_value = const0_rtx;
1918 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1919 /* Remove any possible QUEUED. */
1920 last_expr_value = protect_from_queue (last_expr_value, 0);
1924 TREE_TYPE (t) = last_expr_type;
1925 RTL_EXPR_RTL (t) = last_expr_value;
1926 RTL_EXPR_SEQUENCE (t) = get_insns ();
1928 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1932 /* Don't consider deleting this expr or containing exprs at tree level. */
1933 TREE_SIDE_EFFECTS (t) = 1;
1934 /* Propagate volatility of the actual RTL expr. */
1935 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1938 expr_stmts_for_value--;
1943 /* Generate RTL for the start of an if-then. COND is the expression
1944 whose truth should be tested.
1946 If EXITFLAG is nonzero, this conditional is visible to
1947 `exit_something'. */
1950 expand_start_cond (cond, exitflag)
1954 struct nesting *thiscond = ALLOC_NESTING ();
1956 /* Make an entry on cond_stack for the cond we are entering. */
1958 thiscond->next = cond_stack;
1959 thiscond->all = nesting_stack;
1960 thiscond->depth = ++nesting_depth;
1961 thiscond->data.cond.next_label = gen_label_rtx ();
1962 /* Before we encounter an `else', we don't need a separate exit label
1963 unless there are supposed to be exit statements
1964 to exit this conditional. */
1965 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1966 thiscond->data.cond.endif_label = thiscond->exit_label;
1967 cond_stack = thiscond;
1968 nesting_stack = thiscond;
1970 if (output_bytecode)
1971 bc_expand_start_cond (cond, exitflag);
1973 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1976 /* Generate RTL between then-clause and the elseif-clause
1977 of an if-then-elseif-.... */
1980 expand_start_elseif (cond)
1983 if (cond_stack->data.cond.endif_label == 0)
1984 cond_stack->data.cond.endif_label = gen_label_rtx ();
1985 emit_jump (cond_stack->data.cond.endif_label);
1986 emit_label (cond_stack->data.cond.next_label);
1987 cond_stack->data.cond.next_label = gen_label_rtx ();
1988 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1991 /* Generate RTL between the then-clause and the else-clause
1992 of an if-then-else. */
1995 expand_start_else ()
1997 if (cond_stack->data.cond.endif_label == 0)
1998 cond_stack->data.cond.endif_label = gen_label_rtx ();
2000 if (output_bytecode)
2002 bc_expand_start_else ();
2006 emit_jump (cond_stack->data.cond.endif_label);
2007 emit_label (cond_stack->data.cond.next_label);
2008 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2011 /* After calling expand_start_else, turn this "else" into an "else if"
2012 by providing another condition. */
2015 expand_elseif (cond)
2018 cond_stack->data.cond.next_label = gen_label_rtx ();
2019 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2022 /* Generate RTL for the end of an if-then.
2023 Pop the record for it off of cond_stack. */
2028 struct nesting *thiscond = cond_stack;
2030 if (output_bytecode)
2031 bc_expand_end_cond ();
2034 do_pending_stack_adjust ();
2035 if (thiscond->data.cond.next_label)
2036 emit_label (thiscond->data.cond.next_label);
2037 if (thiscond->data.cond.endif_label)
2038 emit_label (thiscond->data.cond.endif_label);
2041 POPSTACK (cond_stack);
2046 /* Generate code for the start of an if-then. COND is the expression
2047 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2048 is to be visible to exit_something. It is assumed that the caller
2049 has pushed the previous context on the cond stack. */
2052 bc_expand_start_cond (cond, exitflag)
2056 struct nesting *thiscond = cond_stack;
2058 thiscond->data.case_stmt.nominal_type = cond;
2060 thiscond->exit_label = gen_label_rtx ();
2061 bc_expand_expr (cond);
2062 bc_emit_bytecode (xjumpifnot);
2063 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2065 #ifdef DEBUG_PRINT_CODE
2066 fputc ('\n', stderr);
2070 /* Generate the label for the end of an if with
2074 bc_expand_end_cond ()
2076 struct nesting *thiscond = cond_stack;
2078 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2081 /* Generate code for the start of the else- clause of
2085 bc_expand_start_else ()
2087 struct nesting *thiscond = cond_stack;
2089 thiscond->data.cond.endif_label = thiscond->exit_label;
2090 thiscond->exit_label = gen_label_rtx ();
2091 bc_emit_bytecode (jump);
2092 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2094 #ifdef DEBUG_PRINT_CODE
2095 fputc ('\n', stderr);
2098 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2101 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2102 loop should be exited by `exit_something'. This is a loop for which
2103 `expand_continue' will jump to the top of the loop.
2105 Make an entry on loop_stack to record the labels associated with
2109 expand_start_loop (exit_flag)
2112 register struct nesting *thisloop = ALLOC_NESTING ();
2114 /* Make an entry on loop_stack for the loop we are entering. */
2116 thisloop->next = loop_stack;
2117 thisloop->all = nesting_stack;
2118 thisloop->depth = ++nesting_depth;
2119 thisloop->data.loop.start_label = gen_label_rtx ();
2120 thisloop->data.loop.end_label = gen_label_rtx ();
2121 thisloop->data.loop.alt_end_label = 0;
2122 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2123 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2124 loop_stack = thisloop;
2125 nesting_stack = thisloop;
2127 if (output_bytecode)
2129 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2133 do_pending_stack_adjust ();
2135 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2136 emit_label (thisloop->data.loop.start_label);
2141 /* Like expand_start_loop but for a loop where the continuation point
2142 (for expand_continue_loop) will be specified explicitly. */
2145 expand_start_loop_continue_elsewhere (exit_flag)
2148 struct nesting *thisloop = expand_start_loop (exit_flag);
2149 loop_stack->data.loop.continue_label = gen_label_rtx ();
2153 /* Specify the continuation point for a loop started with
2154 expand_start_loop_continue_elsewhere.
2155 Use this at the point in the code to which a continue statement
2159 expand_loop_continue_here ()
2161 if (output_bytecode)
2163 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2166 do_pending_stack_adjust ();
2167 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2168 emit_label (loop_stack->data.loop.continue_label);
2174 bc_expand_end_loop ()
2176 struct nesting *thisloop = loop_stack;
2178 bc_emit_bytecode (jump);
2179 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2181 #ifdef DEBUG_PRINT_CODE
2182 fputc ('\n', stderr);
2185 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2186 POPSTACK (loop_stack);
2191 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2192 Pop the block off of loop_stack. */
2198 register rtx start_label;
2199 rtx last_test_insn = 0;
2202 if (output_bytecode)
2204 bc_expand_end_loop ();
2208 insn = get_last_insn ();
2209 start_label = loop_stack->data.loop.start_label;
2211 /* Mark the continue-point at the top of the loop if none elsewhere. */
2212 if (start_label == loop_stack->data.loop.continue_label)
2213 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2215 do_pending_stack_adjust ();
2217 /* If optimizing, perhaps reorder the loop. If the loop
2218 starts with a conditional exit, roll that to the end
2219 where it will optimize together with the jump back.
2221 We look for the last conditional branch to the exit that we encounter
2222 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2223 branch to the exit first, use it.
2225 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2226 because moving them is not valid. */
2230 ! (GET_CODE (insn) == JUMP_INSN
2231 && GET_CODE (PATTERN (insn)) == SET
2232 && SET_DEST (PATTERN (insn)) == pc_rtx
2233 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2235 /* Scan insns from the top of the loop looking for a qualified
2236 conditional exit. */
2237 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2238 insn = NEXT_INSN (insn))
2240 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2243 if (GET_CODE (insn) == NOTE
2244 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2245 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2248 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2251 if (last_test_insn && num_insns > 30)
2254 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2255 && SET_DEST (PATTERN (insn)) == pc_rtx
2256 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2257 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2258 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2259 == loop_stack->data.loop.end_label)
2260 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2261 == loop_stack->data.loop.alt_end_label)))
2262 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2263 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2264 == loop_stack->data.loop.end_label)
2265 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2266 == loop_stack->data.loop.alt_end_label)))))
2267 last_test_insn = insn;
2269 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2270 && GET_CODE (PATTERN (insn)) == SET
2271 && SET_DEST (PATTERN (insn)) == pc_rtx
2272 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2273 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2274 == loop_stack->data.loop.end_label)
2275 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2276 == loop_stack->data.loop.alt_end_label)))
2277 /* Include BARRIER. */
2278 last_test_insn = NEXT_INSN (insn);
2281 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2283 /* We found one. Move everything from there up
2284 to the end of the loop, and add a jump into the loop
2285 to jump to there. */
2286 register rtx newstart_label = gen_label_rtx ();
2287 register rtx start_move = start_label;
2289 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2290 then we want to move this note also. */
2291 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2292 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2293 == NOTE_INSN_LOOP_CONT))
2294 start_move = PREV_INSN (start_move);
2296 emit_label_after (newstart_label, PREV_INSN (start_move));
2297 reorder_insns (start_move, last_test_insn, get_last_insn ());
2298 emit_jump_insn_after (gen_jump (start_label),
2299 PREV_INSN (newstart_label));
2300 emit_barrier_after (PREV_INSN (newstart_label));
2301 start_label = newstart_label;
2305 emit_jump (start_label);
2306 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2307 emit_label (loop_stack->data.loop.end_label);
2309 POPSTACK (loop_stack);
2314 /* Generate a jump to the current loop's continue-point.
2315 This is usually the top of the loop, but may be specified
2316 explicitly elsewhere. If not currently inside a loop,
2317 return 0 and do nothing; caller will print an error message. */
2320 expand_continue_loop (whichloop)
2321 struct nesting *whichloop;
2325 whichloop = loop_stack;
2328 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2333 /* Generate a jump to exit the current loop. If not currently inside a loop,
2334 return 0 and do nothing; caller will print an error message. */
2337 expand_exit_loop (whichloop)
2338 struct nesting *whichloop;
2342 whichloop = loop_stack;
2345 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2349 /* Generate a conditional jump to exit the current loop if COND
2350 evaluates to zero. If not currently inside a loop,
2351 return 0 and do nothing; caller will print an error message. */
2354 expand_exit_loop_if_false (whichloop, cond)
2355 struct nesting *whichloop;
2360 whichloop = loop_stack;
2363 if (output_bytecode)
2365 bc_expand_expr (cond);
2366 bc_expand_goto_internal (xjumpifnot,
2367 BYTECODE_BC_LABEL (whichloop->exit_label),
2372 /* In order to handle fixups, we actually create a conditional jump
2373 around a unconditional branch to exit the loop. If fixups are
2374 necessary, they go before the unconditional branch. */
2376 rtx label = gen_label_rtx ();
2379 do_jump (cond, NULL_RTX, label);
2380 last_insn = get_last_insn ();
2381 if (GET_CODE (last_insn) == CODE_LABEL)
2382 whichloop->data.loop.alt_end_label = last_insn;
2383 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2391 /* Return non-zero if we should preserve sub-expressions as separate
2392 pseudos. We never do so if we aren't optimizing. We always do so
2393 if -fexpensive-optimizations.
2395 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2396 the loop may still be a small one. */
2399 preserve_subexpressions_p ()
2403 if (flag_expensive_optimizations)
2406 if (optimize == 0 || loop_stack == 0)
2409 insn = get_last_insn_anywhere ();
2412 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2413 < n_non_fixed_regs * 3));
2417 /* Generate a jump to exit the current loop, conditional, binding contour
2418 or case statement. Not all such constructs are visible to this function,
2419 only those started with EXIT_FLAG nonzero. Individual languages use
2420 the EXIT_FLAG parameter to control which kinds of constructs you can
2423 If not currently inside anything that can be exited,
2424 return 0 and do nothing; caller will print an error message. */
2427 expand_exit_something ()
2431 for (n = nesting_stack; n; n = n->all)
2432 if (n->exit_label != 0)
2434 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2441 /* Generate RTL to return from the current function, with no value.
2442 (That is, we do not do anything about returning any value.) */
2445 expand_null_return ()
2447 struct nesting *block = block_stack;
2450 if (output_bytecode)
2452 bc_emit_instruction (ret);
2456 /* Does any pending block have cleanups? */
2458 while (block && block->data.block.cleanups == 0)
2459 block = block->next;
2461 /* If yes, use a goto to return, since that runs cleanups. */
2463 expand_null_return_1 (last_insn, block != 0);
2466 /* Generate RTL to return from the current function, with value VAL. */
2469 expand_value_return (val)
2472 struct nesting *block = block_stack;
2473 rtx last_insn = get_last_insn ();
2474 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2476 /* Copy the value to the return location
2477 unless it's already there. */
2479 if (return_reg != val)
2481 #ifdef PROMOTE_FUNCTION_RETURN
2482 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2483 int unsignedp = TREE_UNSIGNED (type);
2484 enum machine_mode mode
2485 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2488 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2489 convert_move (return_reg, val, unsignedp);
2492 emit_move_insn (return_reg, val);
2494 if (GET_CODE (return_reg) == REG
2495 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2496 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2498 /* Does any pending block have cleanups? */
2500 while (block && block->data.block.cleanups == 0)
2501 block = block->next;
2503 /* If yes, use a goto to return, since that runs cleanups.
2504 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2506 expand_null_return_1 (last_insn, block != 0);
2509 /* Output a return with no value. If LAST_INSN is nonzero,
2510 pretend that the return takes place after LAST_INSN.
2511 If USE_GOTO is nonzero then don't use a return instruction;
2512 go to the return label instead. This causes any cleanups
2513 of pending blocks to be executed normally. */
2516 expand_null_return_1 (last_insn, use_goto)
2520 rtx end_label = cleanup_label ? cleanup_label : return_label;
2522 clear_pending_stack_adjust ();
2523 do_pending_stack_adjust ();
2526 /* PCC-struct return always uses an epilogue. */
2527 if (current_function_returns_pcc_struct || use_goto)
2530 end_label = return_label = gen_label_rtx ();
2531 expand_goto_internal (NULL_TREE, end_label, last_insn);
2535 /* Otherwise output a simple return-insn if one is available,
2536 unless it won't do the job. */
2538 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2540 emit_jump_insn (gen_return ());
2546 /* Otherwise jump to the epilogue. */
2547 expand_goto_internal (NULL_TREE, end_label, last_insn);
2550 /* Generate RTL to evaluate the expression RETVAL and return it
2551 from the current function. */
2554 expand_return (retval)
2557 /* If there are any cleanups to be performed, then they will
2558 be inserted following LAST_INSN. It is desirable
2559 that the last_insn, for such purposes, should be the
2560 last insn before computing the return value. Otherwise, cleanups
2561 which call functions can clobber the return value. */
2562 /* ??? rms: I think that is erroneous, because in C++ it would
2563 run destructors on variables that might be used in the subsequent
2564 computation of the return value. */
2566 register rtx val = 0;
2570 struct nesting *block;
2572 /* Bytecode returns are quite simple, just leave the result on the
2573 arithmetic stack. */
2574 if (output_bytecode)
2576 bc_expand_expr (retval);
2577 bc_emit_instruction (ret);
2581 /* If function wants no value, give it none. */
2582 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2584 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2586 expand_null_return ();
2590 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2591 /* This is not sufficient. We also need to watch for cleanups of the
2592 expression we are about to expand. Unfortunately, we cannot know
2593 if it has cleanups until we expand it, and we want to change how we
2594 expand it depending upon if we need cleanups. We can't win. */
2596 cleanups = any_pending_cleanups (1);
2601 if (TREE_CODE (retval) == RESULT_DECL)
2602 retval_rhs = retval;
2603 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2604 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2605 retval_rhs = TREE_OPERAND (retval, 1);
2606 else if (TREE_TYPE (retval) == void_type_node)
2607 /* Recognize tail-recursive call to void function. */
2608 retval_rhs = retval;
2610 retval_rhs = NULL_TREE;
2612 /* Only use `last_insn' if there are cleanups which must be run. */
2613 if (cleanups || cleanup_label != 0)
2614 last_insn = get_last_insn ();
2616 /* Distribute return down conditional expr if either of the sides
2617 may involve tail recursion (see test below). This enhances the number
2618 of tail recursions we see. Don't do this always since it can produce
2619 sub-optimal code in some cases and we distribute assignments into
2620 conditional expressions when it would help. */
2622 if (optimize && retval_rhs != 0
2623 && frame_offset == 0
2624 && TREE_CODE (retval_rhs) == COND_EXPR
2625 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2626 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2628 rtx label = gen_label_rtx ();
2631 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2632 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2633 DECL_RESULT (current_function_decl),
2634 TREE_OPERAND (retval_rhs, 1));
2635 TREE_SIDE_EFFECTS (expr) = 1;
2636 expand_return (expr);
2639 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2640 DECL_RESULT (current_function_decl),
2641 TREE_OPERAND (retval_rhs, 2));
2642 TREE_SIDE_EFFECTS (expr) = 1;
2643 expand_return (expr);
2647 /* For tail-recursive call to current function,
2648 just jump back to the beginning.
2649 It's unsafe if any auto variable in this function
2650 has its address taken; for simplicity,
2651 require stack frame to be empty. */
2652 if (optimize && retval_rhs != 0
2653 && frame_offset == 0
2654 && TREE_CODE (retval_rhs) == CALL_EXPR
2655 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2656 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2657 /* Finish checking validity, and if valid emit code
2658 to set the argument variables for the new call. */
2659 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2660 DECL_ARGUMENTS (current_function_decl)))
2662 if (tail_recursion_label == 0)
2664 tail_recursion_label = gen_label_rtx ();
2665 emit_label_after (tail_recursion_label,
2666 tail_recursion_reentry);
2669 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2674 /* This optimization is safe if there are local cleanups
2675 because expand_null_return takes care of them.
2676 ??? I think it should also be safe when there is a cleanup label,
2677 because expand_null_return takes care of them, too.
2678 Any reason why not? */
2679 if (HAVE_return && cleanup_label == 0
2680 && ! current_function_returns_pcc_struct
2681 && BRANCH_COST <= 1)
2683 /* If this is return x == y; then generate
2684 if (x == y) return 1; else return 0;
2685 if we can do it with explicit return insns and
2686 branches are cheap. */
2688 switch (TREE_CODE (retval_rhs))
2696 case TRUTH_ANDIF_EXPR:
2697 case TRUTH_ORIF_EXPR:
2698 case TRUTH_AND_EXPR:
2700 case TRUTH_NOT_EXPR:
2701 case TRUTH_XOR_EXPR:
2702 op0 = gen_label_rtx ();
2703 jumpifnot (retval_rhs, op0);
2704 expand_value_return (const1_rtx);
2706 expand_value_return (const0_rtx);
2710 #endif /* HAVE_return */
2712 /* If the result is an aggregate that is being returned in one (or more)
2713 registers, load the registers here. The compiler currently can't handle
2714 copying a BLKmode value into registers. We could put this code in a
2715 more general area (for use by everyone instead of just function
2716 call/return), but until this feature is generally usable it is kept here
2717 (and in expand_call). The value must go into a pseudo in case there
2718 are cleanups that will clobber the real return register. */
2721 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2722 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2725 int big_endian_correction = 0;
2726 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2727 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2728 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2730 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2731 enum machine_mode tmpmode, result_reg_mode;
2733 /* Structures smaller than a word are aligned to the least significant
2734 byte (to the right). On a BYTES_BIG_ENDIAN machine, this means we
2735 must skip the empty high order bytes when calculating the bit
2737 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
2738 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
2740 for (i = 0; i < n_regs; i++)
2742 rtx reg = gen_reg_rtx (word_mode);
2743 rtx word = operand_subword_force (result_val, i, BLKmode);
2744 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2747 result_pseudos[i] = reg;
2749 /* Clobber REG and move each partword into it. Ensure we don't
2750 go past the end of the structure. Note that the loop below
2751 works because we've already verified that padding and
2752 endianness are compatible. */
2753 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
2756 bitpos < BITS_PER_WORD && bytes > 0;
2757 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
2759 int xbitpos = bitpos + big_endian_correction;
2761 store_bit_field (reg, bitsize, xbitpos, word_mode,
2762 extract_bit_field (word, bitsize, bitpos, 1,
2763 NULL_RTX, word_mode,
2765 bitsize / BITS_PER_UNIT,
2767 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2771 /* Find the smallest integer mode large enough to hold the
2772 entire structure and use that mode instead of BLKmode
2773 on the USE insn for the return register. */
2774 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2775 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2776 tmpmode != MAX_MACHINE_MODE;
2777 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2779 /* Have we found a large enough mode? */
2780 if (GET_MODE_SIZE (tmpmode) >= bytes)
2784 /* No suitable mode found. */
2785 if (tmpmode == MAX_MACHINE_MODE)
2788 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2790 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2791 result_reg_mode = word_mode;
2793 result_reg_mode = tmpmode;
2794 result_reg = gen_reg_rtx (result_reg_mode);
2796 /* Now that the value is in pseudos, copy it to the result reg(s). */
2799 for (i = 0; i < n_regs; i++)
2800 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2803 if (tmpmode != result_reg_mode)
2804 result_reg = gen_lowpart (tmpmode, result_reg);
2806 expand_value_return (result_reg);
2810 && TREE_TYPE (retval_rhs) != void_type_node
2811 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2813 /* Calculate the return value into a pseudo reg. */
2814 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2816 /* All temporaries have now been used. */
2818 /* Return the calculated value, doing cleanups first. */
2819 expand_value_return (val);
2823 /* No cleanups or no hard reg used;
2824 calculate value into hard return reg. */
2825 expand_expr (retval, const0_rtx, VOIDmode, 0);
2828 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2832 /* Return 1 if the end of the generated RTX is not a barrier.
2833 This means code already compiled can drop through. */
2836 drop_through_at_end_p ()
2838 rtx insn = get_last_insn ();
2839 while (insn && GET_CODE (insn) == NOTE)
2840 insn = PREV_INSN (insn);
2841 return insn && GET_CODE (insn) != BARRIER;
2844 /* Emit code to alter this function's formal parms for a tail-recursive call.
2845 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2846 FORMALS is the chain of decls of formals.
2847 Return 1 if this can be done;
2848 otherwise return 0 and do not emit any code. */
2851 tail_recursion_args (actuals, formals)
2852 tree actuals, formals;
2854 register tree a = actuals, f = formals;
2856 register rtx *argvec;
2858 /* Check that number and types of actuals are compatible
2859 with the formals. This is not always true in valid C code.
2860 Also check that no formal needs to be addressable
2861 and that all formals are scalars. */
2863 /* Also count the args. */
2865 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2867 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2869 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2872 if (a != 0 || f != 0)
2875 /* Compute all the actuals. */
2877 argvec = (rtx *) alloca (i * sizeof (rtx));
2879 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2880 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2882 /* Find which actual values refer to current values of previous formals.
2883 Copy each of them now, before any formal is changed. */
2885 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2889 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2890 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2891 { copy = 1; break; }
2893 argvec[i] = copy_to_reg (argvec[i]);
2896 /* Store the values of the actuals into the formals. */
2898 for (f = formals, a = actuals, i = 0; f;
2899 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2901 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2902 emit_move_insn (DECL_RTL (f), argvec[i]);
2904 convert_move (DECL_RTL (f), argvec[i],
2905 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2912 /* Generate the RTL code for entering a binding contour.
2913 The variables are declared one by one, by calls to `expand_decl'.
2915 EXIT_FLAG is nonzero if this construct should be visible to
2916 `exit_something'. */
2919 expand_start_bindings (exit_flag)
2922 struct nesting *thisblock = ALLOC_NESTING ();
2923 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2925 /* Make an entry on block_stack for the block we are entering. */
2927 thisblock->next = block_stack;
2928 thisblock->all = nesting_stack;
2929 thisblock->depth = ++nesting_depth;
2930 thisblock->data.block.stack_level = 0;
2931 thisblock->data.block.cleanups = 0;
2932 thisblock->data.block.function_call_count = 0;
2936 if (block_stack->data.block.cleanups == NULL_TREE
2937 && (block_stack->data.block.outer_cleanups == NULL_TREE
2938 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2939 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2941 thisblock->data.block.outer_cleanups
2942 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2943 block_stack->data.block.outer_cleanups);
2946 thisblock->data.block.outer_cleanups = 0;
2950 && !(block_stack->data.block.cleanups == NULL_TREE
2951 && block_stack->data.block.outer_cleanups == NULL_TREE))
2952 thisblock->data.block.outer_cleanups
2953 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2954 block_stack->data.block.outer_cleanups);
2956 thisblock->data.block.outer_cleanups = 0;
2958 thisblock->data.block.label_chain = 0;
2959 thisblock->data.block.innermost_stack_block = stack_block_stack;
2960 thisblock->data.block.first_insn = note;
2961 thisblock->data.block.block_start_count = ++block_start_count;
2962 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2963 block_stack = thisblock;
2964 nesting_stack = thisblock;
2966 if (!output_bytecode)
2968 /* Make a new level for allocating stack slots. */
2973 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2974 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2978 remember_end_note (block)
2979 register tree block;
2981 BLOCK_END_NOTE (block) = last_block_end_note;
2982 last_block_end_note = NULL_RTX;
2985 /* Generate RTL code to terminate a binding contour.
2986 VARS is the chain of VAR_DECL nodes
2987 for the variables bound in this contour.
2988 MARK_ENDS is nonzero if we should put a note at the beginning
2989 and end of this binding contour.
2991 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
2992 (That is true automatically if the contour has a saved stack level.) */
2995 expand_end_bindings (vars, mark_ends, dont_jump_in)
3000 register struct nesting *thisblock = block_stack;
3003 if (output_bytecode)
3005 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
3010 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3011 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
3012 && ! DECL_IN_SYSTEM_HEADER (decl))
3013 warning_with_decl (decl, "unused variable `%s'");
3015 if (thisblock->exit_label)
3017 do_pending_stack_adjust ();
3018 emit_label (thisblock->exit_label);
3021 /* If necessary, make a handler for nonlocal gotos taking
3022 place in the function calls in this block. */
3023 if (function_call_count != thisblock->data.block.function_call_count
3025 /* Make handler for outermost block
3026 if there were any nonlocal gotos to this function. */
3027 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3028 /* Make handler for inner block if it has something
3029 special to do when you jump out of it. */
3030 : (thisblock->data.block.cleanups != 0
3031 || thisblock->data.block.stack_level != 0)))
3034 rtx afterward = gen_label_rtx ();
3035 rtx handler_label = gen_label_rtx ();
3036 rtx save_receiver = gen_reg_rtx (Pmode);
3039 /* Don't let jump_optimize delete the handler. */
3040 LABEL_PRESERVE_P (handler_label) = 1;
3042 /* Record the handler address in the stack slot for that purpose,
3043 during this block, saving and restoring the outer value. */
3044 if (thisblock->next != 0)
3046 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3049 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3050 insns = get_insns ();
3052 emit_insns_before (insns, thisblock->data.block.first_insn);
3056 emit_move_insn (nonlocal_goto_handler_slot,
3057 gen_rtx (LABEL_REF, Pmode, handler_label));
3058 insns = get_insns ();
3060 emit_insns_before (insns, thisblock->data.block.first_insn);
3062 /* Jump around the handler; it runs only when specially invoked. */
3063 emit_jump (afterward);
3064 emit_label (handler_label);
3066 #ifdef HAVE_nonlocal_goto
3067 if (! HAVE_nonlocal_goto)
3069 /* First adjust our frame pointer to its actual value. It was
3070 previously set to the start of the virtual area corresponding to
3071 the stacked variables when we branched here and now needs to be
3072 adjusted to the actual hardware fp value.
3074 Assignments are to virtual registers are converted by
3075 instantiate_virtual_regs into the corresponding assignment
3076 to the underlying register (fp in this case) that makes
3077 the original assignment true.
3078 So the following insn will actually be
3079 decrementing fp by STARTING_FRAME_OFFSET. */
3080 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3082 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3083 if (fixed_regs[ARG_POINTER_REGNUM])
3085 #ifdef ELIMINABLE_REGS
3086 /* If the argument pointer can be eliminated in favor of the
3087 frame pointer, we don't need to restore it. We assume here
3088 that if such an elimination is present, it can always be used.
3089 This is the case on all known machines; if we don't make this
3090 assumption, we do unnecessary saving on many machines. */
3091 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3094 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3095 if (elim_regs[i].from == ARG_POINTER_REGNUM
3096 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3099 if (i == sizeof elim_regs / sizeof elim_regs [0])
3102 /* Now restore our arg pointer from the address at which it
3103 was saved in our stack frame.
3104 If there hasn't be space allocated for it yet, make
3106 if (arg_pointer_save_area == 0)
3107 arg_pointer_save_area
3108 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3109 emit_move_insn (virtual_incoming_args_rtx,
3110 /* We need a pseudo here, or else
3111 instantiate_virtual_regs_1 complains. */
3112 copy_to_reg (arg_pointer_save_area));
3117 /* The handler expects the desired label address in the static chain
3118 register. It tests the address and does an appropriate jump
3119 to whatever label is desired. */
3120 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3121 /* Skip any labels we shouldn't be able to jump to from here. */
3122 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3124 rtx not_this = gen_label_rtx ();
3125 rtx this = gen_label_rtx ();
3126 do_jump_if_equal (static_chain_rtx,
3127 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3129 emit_jump (not_this);
3131 expand_goto (TREE_VALUE (link));
3132 emit_label (not_this);
3134 /* If label is not recognized, abort. */
3135 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3138 emit_label (afterward);
3141 /* Don't allow jumping into a block that has cleanups or a stack level. */
3143 || thisblock->data.block.stack_level != 0
3144 || thisblock->data.block.cleanups != 0)
3146 struct label_chain *chain;
3148 /* Any labels in this block are no longer valid to go to.
3149 Mark them to cause an error message. */
3150 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3152 DECL_TOO_LATE (chain->label) = 1;
3153 /* If any goto without a fixup came to this label,
3154 that must be an error, because gotos without fixups
3155 come from outside all saved stack-levels and all cleanups. */
3156 if (TREE_ADDRESSABLE (chain->label))
3157 error_with_decl (chain->label,
3158 "label `%s' used before containing binding contour");
3162 /* Restore stack level in effect before the block
3163 (only if variable-size objects allocated). */
3164 /* Perform any cleanups associated with the block. */
3166 if (thisblock->data.block.stack_level != 0
3167 || thisblock->data.block.cleanups != 0)
3169 /* Only clean up here if this point can actually be reached. */
3170 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3172 /* Don't let cleanups affect ({...}) constructs. */
3173 int old_expr_stmts_for_value = expr_stmts_for_value;
3174 rtx old_last_expr_value = last_expr_value;
3175 tree old_last_expr_type = last_expr_type;
3176 expr_stmts_for_value = 0;
3178 /* Do the cleanups. */
3179 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3181 do_pending_stack_adjust ();
3183 expr_stmts_for_value = old_expr_stmts_for_value;
3184 last_expr_value = old_last_expr_value;
3185 last_expr_type = old_last_expr_type;
3187 /* Restore the stack level. */
3189 if (reachable && thisblock->data.block.stack_level != 0)
3191 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3192 thisblock->data.block.stack_level, NULL_RTX);
3193 if (nonlocal_goto_handler_slot != 0)
3194 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3198 /* Any gotos out of this block must also do these things.
3199 Also report any gotos with fixups that came to labels in this
3201 fixup_gotos (thisblock,
3202 thisblock->data.block.stack_level,
3203 thisblock->data.block.cleanups,
3204 thisblock->data.block.first_insn,
3208 /* Mark the beginning and end of the scope if requested.
3209 We do this now, after running cleanups on the variables
3210 just going out of scope, so they are in scope for their cleanups. */
3213 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3215 /* Get rid of the beginning-mark if we don't make an end-mark. */
3216 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3218 /* If doing stupid register allocation, make sure lives of all
3219 register variables declared here extend thru end of scope. */
3222 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3224 rtx rtl = DECL_RTL (decl);
3225 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3229 /* Restore block_stack level for containing block. */
3231 stack_block_stack = thisblock->data.block.innermost_stack_block;
3232 POPSTACK (block_stack);
3234 /* Pop the stack slot nesting and free any slots at this level. */
3239 /* End a binding contour.
3240 VARS is the chain of VAR_DECL nodes for the variables bound
3241 in this contour. MARK_ENDS is nonzer if we should put a note
3242 at the beginning and end of this binding contour.
3243 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3247 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3252 struct nesting *thisbind = nesting_stack;
3256 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3257 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3258 warning_with_decl (decl, "unused variable `%s'");
3260 if (thisbind->exit_label)
3261 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3263 /* Pop block/bindings off stack */
3264 POPSTACK (block_stack);
3267 /* Generate RTL for the automatic variable declaration DECL.
3268 (Other kinds of declarations are simply ignored if seen here.)
3269 CLEANUP is an expression to be executed at exit from this binding contour;
3270 for example, in C++, it might call the destructor for this variable.
3272 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3273 either before or after calling `expand_decl' but before compiling
3274 any subsequent expressions. This is because CLEANUP may be expanded
3275 more than once, on different branches of execution.
3276 For the same reason, CLEANUP may not contain a CALL_EXPR
3277 except as its topmost node--else `preexpand_calls' would get confused.
3279 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3280 that is not associated with any particular variable.
3282 There is no special support here for C++ constructors.
3283 They should be handled by the proper code in DECL_INITIAL. */
3289 struct nesting *thisblock = block_stack;
3292 if (output_bytecode)
3294 bc_expand_decl (decl, 0);
3298 type = TREE_TYPE (decl);
3300 /* Only automatic variables need any expansion done.
3301 Static and external variables, and external functions,
3302 will be handled by `assemble_variable' (called from finish_decl).
3303 TYPE_DECL and CONST_DECL require nothing.
3304 PARM_DECLs are handled in `assign_parms'. */
3306 if (TREE_CODE (decl) != VAR_DECL)
3308 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3311 /* Create the RTL representation for the variable. */
3313 if (type == error_mark_node)
3314 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3315 else if (DECL_SIZE (decl) == 0)
3316 /* Variable with incomplete type. */
3318 if (DECL_INITIAL (decl) == 0)
3319 /* Error message was already done; now avoid a crash. */
3320 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3322 /* An initializer is going to decide the size of this array.
3323 Until we know the size, represent its address with a reg. */
3324 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3325 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3327 else if (DECL_MODE (decl) != BLKmode
3328 /* If -ffloat-store, don't put explicit float vars
3330 && !(flag_float_store
3331 && TREE_CODE (type) == REAL_TYPE)
3332 && ! TREE_THIS_VOLATILE (decl)
3333 && ! TREE_ADDRESSABLE (decl)
3334 && (DECL_REGISTER (decl) || ! obey_regdecls))
3336 /* Automatic variable that can go in a register. */
3337 int unsignedp = TREE_UNSIGNED (type);
3338 enum machine_mode reg_mode
3339 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3341 if (TREE_CODE (type) == COMPLEX_TYPE)
3343 rtx realpart, imagpart;
3344 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3346 /* For a complex type variable, make a CONCAT of two pseudos
3347 so that the real and imaginary parts
3348 can be allocated separately. */
3349 realpart = gen_reg_rtx (partmode);
3350 REG_USERVAR_P (realpart) = 1;
3351 imagpart = gen_reg_rtx (partmode);
3352 REG_USERVAR_P (imagpart) = 1;
3353 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3357 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3358 if (TREE_CODE (type) == POINTER_TYPE)
3359 mark_reg_pointer (DECL_RTL (decl));
3360 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3363 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3365 /* Variable of fixed size that goes on the stack. */
3369 /* If we previously made RTL for this decl, it must be an array
3370 whose size was determined by the initializer.
3371 The old address was a register; set that register now
3372 to the proper address. */
3373 if (DECL_RTL (decl) != 0)
3375 if (GET_CODE (DECL_RTL (decl)) != MEM
3376 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3378 oldaddr = XEXP (DECL_RTL (decl), 0);
3382 = assign_stack_temp (DECL_MODE (decl),
3383 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3384 + BITS_PER_UNIT - 1)
3387 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3389 /* Set alignment we actually gave this decl. */
3390 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3391 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3395 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3396 if (addr != oldaddr)
3397 emit_move_insn (oldaddr, addr);
3400 /* If this is a memory ref that contains aggregate components,
3401 mark it as such for cse and loop optimize. */
3402 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3404 /* If this is in memory because of -ffloat-store,
3405 set the volatile bit, to prevent optimizations from
3406 undoing the effects. */
3407 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3408 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3412 /* Dynamic-size object: must push space on the stack. */
3416 /* Record the stack pointer on entry to block, if have
3417 not already done so. */
3418 if (thisblock->data.block.stack_level == 0)
3420 do_pending_stack_adjust ();
3421 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3422 &thisblock->data.block.stack_level,
3423 thisblock->data.block.first_insn);
3424 stack_block_stack = thisblock;
3427 /* Compute the variable's size, in bytes. */
3428 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3430 size_int (BITS_PER_UNIT)),
3431 NULL_RTX, VOIDmode, 0);
3434 /* Allocate space on the stack for the variable. */
3435 address = allocate_dynamic_stack_space (size, NULL_RTX,
3438 /* Reference the variable indirect through that rtx. */
3439 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3441 /* If this is a memory ref that contains aggregate components,
3442 mark it as such for cse and loop optimize. */
3443 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3445 /* Indicate the alignment we actually gave this variable. */
3446 #ifdef STACK_BOUNDARY
3447 DECL_ALIGN (decl) = STACK_BOUNDARY;
3449 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3453 if (TREE_THIS_VOLATILE (decl))
3454 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3455 #if 0 /* A variable is not necessarily unchanging
3456 just because it is const. RTX_UNCHANGING_P
3457 means no change in the function,
3458 not merely no change in the variable's scope.
3459 It is correct to set RTX_UNCHANGING_P if the variable's scope
3460 is the whole function. There's no convenient way to test that. */
3461 if (TREE_READONLY (decl))
3462 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3465 /* If doing stupid register allocation, make sure life of any
3466 register variable starts here, at the start of its scope. */
3469 use_variable (DECL_RTL (decl));
3473 /* Generate code for the automatic variable declaration DECL. For
3474 most variables this just means we give it a stack offset. The
3475 compiler sometimes emits cleanups without variables and we will
3476 have to deal with those too. */
3479 bc_expand_decl (decl, cleanup)
3487 /* A cleanup with no variable. */
3494 /* Only auto variables need any work. */
3495 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3498 type = TREE_TYPE (decl);
3500 if (type == error_mark_node)
3501 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3503 else if (DECL_SIZE (decl) == 0)
3505 /* Variable with incomplete type. The stack offset herein will be
3506 fixed later in expand_decl_init (). */
3507 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3509 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3511 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3515 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3518 /* Emit code to perform the initialization of a declaration DECL. */
3521 expand_decl_init (decl)
3524 int was_used = TREE_USED (decl);
3526 if (output_bytecode)
3528 bc_expand_decl_init (decl);
3532 /* If this is a CONST_DECL, we don't have to generate any code, but
3533 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3534 to be set while in the obstack containing the constant. If we don't
3535 do this, we can lose if we have functions nested three deep and the middle
3536 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3537 the innermost function is the first to expand that STRING_CST. */
3538 if (TREE_CODE (decl) == CONST_DECL)
3540 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3541 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3542 EXPAND_INITIALIZER);
3546 if (TREE_STATIC (decl))
3549 /* Compute and store the initial value now. */
3551 if (DECL_INITIAL (decl) == error_mark_node)
3553 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3554 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3555 || code == POINTER_TYPE)
3556 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3560 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3562 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3563 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3567 /* Don't let the initialization count as "using" the variable. */
3568 TREE_USED (decl) = was_used;
3570 /* Free any temporaries we made while initializing the decl. */
3571 preserve_temp_slots (NULL_RTX);
3575 /* Expand initialization for variable-sized types. Allocate array
3576 using newlocalSI and set local variable, which is a pointer to the
3580 bc_expand_variable_local_init (decl)
3583 /* Evaluate size expression and coerce to SI */
3584 bc_expand_expr (DECL_SIZE (decl));
3586 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3587 no coercion is necessary (?) */
3589 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3590 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3592 /* Emit code to allocate array */
3593 bc_emit_instruction (newlocalSI);
3595 /* Store array pointer in local variable. This is the only instance
3596 where we actually want the address of the pointer to the
3597 variable-size block, rather than the pointer itself. We avoid
3598 using expand_address() since that would cause the pointer to be
3599 pushed rather than its address. Hence the hard-coded reference;
3600 notice also that the variable is always local (no global
3601 variable-size type variables). */
3603 bc_load_localaddr (DECL_RTL (decl));
3604 bc_emit_instruction (storeP);
3608 /* Emit code to initialize a declaration. */
3611 bc_expand_decl_init (decl)
3614 int org_stack_depth;
3616 /* Statical initializers are handled elsewhere */
3618 if (TREE_STATIC (decl))
3621 /* Memory original stack depth */
3622 org_stack_depth = stack_depth;
3624 /* If the type is variable-size, we first create its space (we ASSUME
3625 it CAN'T be static). We do this regardless of whether there's an
3626 initializer assignment or not. */
3628 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3629 bc_expand_variable_local_init (decl);
3631 /* Expand initializer assignment */
3632 if (DECL_INITIAL (decl) == error_mark_node)
3634 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3636 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3637 || code == POINTER_TYPE)
3639 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3641 else if (DECL_INITIAL (decl))
3642 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3644 /* Restore stack depth */
3645 if (org_stack_depth > stack_depth)
3648 bc_adjust_stack (stack_depth - org_stack_depth);
3652 /* CLEANUP is an expression to be executed at exit from this binding contour;
3653 for example, in C++, it might call the destructor for this variable.
3655 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3656 either before or after calling `expand_decl' but before compiling
3657 any subsequent expressions. This is because CLEANUP may be expanded
3658 more than once, on different branches of execution.
3659 For the same reason, CLEANUP may not contain a CALL_EXPR
3660 except as its topmost node--else `preexpand_calls' would get confused.
3662 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3663 that is not associated with any particular variable. */
3666 expand_decl_cleanup (decl, cleanup)
3669 struct nesting *thisblock = block_stack;
3671 /* Error if we are not in any block. */
3675 /* Record the cleanup if there is one. */
3679 thisblock->data.block.cleanups
3680 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3681 /* If this block has a cleanup, it belongs in stack_block_stack. */
3682 stack_block_stack = thisblock;
3683 (*interim_eh_hook) (NULL_TREE);
3688 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3689 DECL_ELTS is the list of elements that belong to DECL's type.
3690 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3693 expand_anon_union_decl (decl, cleanup, decl_elts)
3694 tree decl, cleanup, decl_elts;
3696 struct nesting *thisblock = block_stack;
3699 expand_decl (decl, cleanup);
3700 x = DECL_RTL (decl);
3704 tree decl_elt = TREE_VALUE (decl_elts);
3705 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3706 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3708 /* Propagate the union's alignment to the elements. */
3709 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3711 /* If the element has BLKmode and the union doesn't, the union is
3712 aligned such that the element doesn't need to have BLKmode, so
3713 change the element's mode to the appropriate one for its size. */
3714 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3715 DECL_MODE (decl_elt) = mode
3716 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3719 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3720 instead create a new MEM rtx with the proper mode. */
3721 if (GET_CODE (x) == MEM)
3723 if (mode == GET_MODE (x))
3724 DECL_RTL (decl_elt) = x;
3727 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3728 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3729 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3732 else if (GET_CODE (x) == REG)
3734 if (mode == GET_MODE (x))
3735 DECL_RTL (decl_elt) = x;
3737 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3742 /* Record the cleanup if there is one. */
3745 thisblock->data.block.cleanups
3746 = temp_tree_cons (decl_elt, cleanup_elt,
3747 thisblock->data.block.cleanups);
3749 decl_elts = TREE_CHAIN (decl_elts);
3753 /* Expand a list of cleanups LIST.
3754 Elements may be expressions or may be nested lists.
3756 If DONT_DO is nonnull, then any list-element
3757 whose TREE_PURPOSE matches DONT_DO is omitted.
3758 This is sometimes used to avoid a cleanup associated with
3759 a value that is being returned out of the scope.
3761 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3762 goto and handle protection regions specially in that case.
3764 If REACHABLE, we emit code, otherwise just inform the exception handling
3765 code about this finalization. */
3768 expand_cleanups (list, dont_do, in_fixup, reachable)
3775 for (tail = list; tail; tail = TREE_CHAIN (tail))
3776 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3778 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3779 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3783 (*interim_eh_hook) (TREE_VALUE (tail));
3787 /* Cleanups may be run multiple times. For example,
3788 when exiting a binding contour, we expand the
3789 cleanups associated with that contour. When a goto
3790 within that binding contour has a target outside that
3791 contour, it will expand all cleanups from its scope to
3792 the target. Though the cleanups are expanded multiple
3793 times, the control paths are non-overlapping so the
3794 cleanups will not be executed twice. */
3795 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3802 /* Move all cleanups from the current block_stack
3803 to the containing block_stack, where they are assumed to
3804 have been created. If anything can cause a temporary to
3805 be created, but not expanded for more than one level of
3806 block_stacks, then this code will have to change. */
3811 struct nesting *block = block_stack;
3812 struct nesting *outer = block->next;
3814 outer->data.block.cleanups
3815 = chainon (block->data.block.cleanups,
3816 outer->data.block.cleanups);
3817 block->data.block.cleanups = 0;
3821 last_cleanup_this_contour ()
3823 if (block_stack == 0)
3826 return block_stack->data.block.cleanups;
3829 /* Return 1 if there are any pending cleanups at this point.
3830 If THIS_CONTOUR is nonzero, check the current contour as well.
3831 Otherwise, look only at the contours that enclose this one. */
3834 any_pending_cleanups (this_contour)
3837 struct nesting *block;
3839 if (block_stack == 0)
3842 if (this_contour && block_stack->data.block.cleanups != NULL)
3844 if (block_stack->data.block.cleanups == 0
3845 && (block_stack->data.block.outer_cleanups == 0
3847 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3852 for (block = block_stack->next; block; block = block->next)
3853 if (block->data.block.cleanups != 0)
3859 /* Enter a case (Pascal) or switch (C) statement.
3860 Push a block onto case_stack and nesting_stack
3861 to accumulate the case-labels that are seen
3862 and to record the labels generated for the statement.
3864 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3865 Otherwise, this construct is transparent for `exit_something'.
3867 EXPR is the index-expression to be dispatched on.
3868 TYPE is its nominal type. We could simply convert EXPR to this type,
3869 but instead we take short cuts. */
3872 expand_start_case (exit_flag, expr, type, printname)
3878 register struct nesting *thiscase = ALLOC_NESTING ();
3880 /* Make an entry on case_stack for the case we are entering. */
3882 thiscase->next = case_stack;
3883 thiscase->all = nesting_stack;
3884 thiscase->depth = ++nesting_depth;
3885 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3886 thiscase->data.case_stmt.case_list = 0;
3887 thiscase->data.case_stmt.index_expr = expr;
3888 thiscase->data.case_stmt.nominal_type = type;
3889 thiscase->data.case_stmt.default_label = 0;
3890 thiscase->data.case_stmt.num_ranges = 0;
3891 thiscase->data.case_stmt.printname = printname;
3892 thiscase->data.case_stmt.seenlabel = 0;
3893 case_stack = thiscase;
3894 nesting_stack = thiscase;
3896 if (output_bytecode)
3898 bc_expand_start_case (thiscase, expr, type, printname);
3902 do_pending_stack_adjust ();
3904 /* Make sure case_stmt.start points to something that won't
3905 need any transformation before expand_end_case. */
3906 if (GET_CODE (get_last_insn ()) != NOTE)
3907 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3909 thiscase->data.case_stmt.start = get_last_insn ();
3913 /* Enter a case statement. It is assumed that the caller has pushed
3914 the current context onto the case stack. */
3917 bc_expand_start_case (thiscase, expr, type, printname)
3918 struct nesting *thiscase;
3923 bc_expand_expr (expr);
3924 bc_expand_conversion (TREE_TYPE (expr), type);
3926 /* For cases, the skip is a place we jump to that's emitted after
3927 the size of the jump table is known. */
3929 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3930 bc_emit_bytecode (jump);
3931 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3933 #ifdef DEBUG_PRINT_CODE
3934 fputc ('\n', stderr);
3939 /* Start a "dummy case statement" within which case labels are invalid
3940 and are not connected to any larger real case statement.
3941 This can be used if you don't want to let a case statement jump
3942 into the middle of certain kinds of constructs. */
3945 expand_start_case_dummy ()
3947 register struct nesting *thiscase = ALLOC_NESTING ();
3949 /* Make an entry on case_stack for the dummy. */
3951 thiscase->next = case_stack;
3952 thiscase->all = nesting_stack;
3953 thiscase->depth = ++nesting_depth;
3954 thiscase->exit_label = 0;
3955 thiscase->data.case_stmt.case_list = 0;
3956 thiscase->data.case_stmt.start = 0;
3957 thiscase->data.case_stmt.nominal_type = 0;
3958 thiscase->data.case_stmt.default_label = 0;
3959 thiscase->data.case_stmt.num_ranges = 0;
3960 case_stack = thiscase;
3961 nesting_stack = thiscase;
3964 /* End a dummy case statement. */
3967 expand_end_case_dummy ()
3969 POPSTACK (case_stack);
3972 /* Return the data type of the index-expression
3973 of the innermost case statement, or null if none. */
3976 case_index_expr_type ()
3979 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3983 /* Accumulate one case or default label inside a case or switch statement.
3984 VALUE is the value of the case (a null pointer, for a default label).
3985 The function CONVERTER, when applied to arguments T and V,
3986 converts the value V to the type T.
3988 If not currently inside a case or switch statement, return 1 and do
3989 nothing. The caller will print a language-specific error message.
3990 If VALUE is a duplicate or overlaps, return 2 and do nothing
3991 except store the (first) duplicate node in *DUPLICATE.
3992 If VALUE is out of range, return 3 and do nothing.
3993 If we are jumping into the scope of a cleaup or var-sized array, return 5.
3994 Return 0 on success.
3996 Extended to handle range statements. */
3999 pushcase (value, converter, label, duplicate)
4000 register tree value;
4001 tree (*converter) PROTO((tree, tree));
4002 register tree label;
4005 register struct case_node **l;
4006 register struct case_node *n;
4010 if (output_bytecode)
4011 return bc_pushcase (value, label);
4013 /* Fail if not inside a real case statement. */
4014 if (! (case_stack && case_stack->data.case_stmt.start))
4017 if (stack_block_stack
4018 && stack_block_stack->depth > case_stack->depth)
4021 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4022 nominal_type = case_stack->data.case_stmt.nominal_type;
4024 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4025 if (index_type == error_mark_node)
4028 /* Convert VALUE to the type in which the comparisons are nominally done. */
4030 value = (*converter) (nominal_type, value);
4032 /* If this is the first label, warn if any insns have been emitted. */
4033 if (case_stack->data.case_stmt.seenlabel == 0)
4036 for (insn = case_stack->data.case_stmt.start;
4038 insn = NEXT_INSN (insn))
4040 if (GET_CODE (insn) == CODE_LABEL)
4042 if (GET_CODE (insn) != NOTE
4043 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4045 warning ("unreachable code at beginning of %s",
4046 case_stack->data.case_stmt.printname);
4051 case_stack->data.case_stmt.seenlabel = 1;
4053 /* Fail if this value is out of range for the actual type of the index
4054 (which may be narrower than NOMINAL_TYPE). */
4055 if (value != 0 && ! int_fits_type_p (value, index_type))
4058 /* Fail if this is a duplicate or overlaps another entry. */
4061 if (case_stack->data.case_stmt.default_label != 0)
4063 *duplicate = case_stack->data.case_stmt.default_label;
4066 case_stack->data.case_stmt.default_label = label;
4070 /* Find the elt in the chain before which to insert the new value,
4071 to keep the chain sorted in increasing order.
4072 But report an error if this element is a duplicate. */
4073 for (l = &case_stack->data.case_stmt.case_list;
4074 /* Keep going past elements distinctly less than VALUE. */
4075 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4080 /* Element we will insert before must be distinctly greater;
4081 overlap means error. */
4082 if (! tree_int_cst_lt (value, (*l)->low))
4084 *duplicate = (*l)->code_label;
4089 /* Add this label to the chain, and succeed.
4090 Copy VALUE so it is on temporary rather than momentary
4091 obstack and will thus survive till the end of the case statement. */
4092 n = (struct case_node *) oballoc (sizeof (struct case_node));
4095 n->high = n->low = copy_node (value);
4096 n->code_label = label;
4100 expand_label (label);
4104 /* Like pushcase but this case applies to all values
4105 between VALUE1 and VALUE2 (inclusive).
4106 The return value is the same as that of pushcase
4107 but there is one additional error code:
4108 4 means the specified range was empty. */
4111 pushcase_range (value1, value2, converter, label, duplicate)
4112 register tree value1, value2;
4113 tree (*converter) PROTO((tree, tree));
4114 register tree label;
4117 register struct case_node **l;
4118 register struct case_node *n;
4122 /* Fail if not inside a real case statement. */
4123 if (! (case_stack && case_stack->data.case_stmt.start))
4126 if (stack_block_stack
4127 && stack_block_stack->depth > case_stack->depth)
4130 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4131 nominal_type = case_stack->data.case_stmt.nominal_type;
4133 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4134 if (index_type == error_mark_node)
4137 /* If this is the first label, warn if any insns have been emitted. */
4138 if (case_stack->data.case_stmt.seenlabel == 0)
4141 for (insn = case_stack->data.case_stmt.start;
4143 insn = NEXT_INSN (insn))
4145 if (GET_CODE (insn) == CODE_LABEL)
4147 if (GET_CODE (insn) != NOTE
4148 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4150 warning ("unreachable code at beginning of %s",
4151 case_stack->data.case_stmt.printname);
4156 case_stack->data.case_stmt.seenlabel = 1;
4158 /* Convert VALUEs to type in which the comparisons are nominally done. */
4159 if (value1 == 0) /* Negative infinity. */
4160 value1 = TYPE_MIN_VALUE(index_type);
4161 value1 = (*converter) (nominal_type, value1);
4163 if (value2 == 0) /* Positive infinity. */
4164 value2 = TYPE_MAX_VALUE(index_type);
4165 value2 = (*converter) (nominal_type, value2);
4167 /* Fail if these values are out of range. */
4168 if (! int_fits_type_p (value1, index_type))
4171 if (! int_fits_type_p (value2, index_type))
4174 /* Fail if the range is empty. */
4175 if (tree_int_cst_lt (value2, value1))
4178 /* If the bounds are equal, turn this into the one-value case. */
4179 if (tree_int_cst_equal (value1, value2))
4180 return pushcase (value1, converter, label, duplicate);
4182 /* Find the elt in the chain before which to insert the new value,
4183 to keep the chain sorted in increasing order.
4184 But report an error if this element is a duplicate. */
4185 for (l = &case_stack->data.case_stmt.case_list;
4186 /* Keep going past elements distinctly less than this range. */
4187 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4192 /* Element we will insert before must be distinctly greater;
4193 overlap means error. */
4194 if (! tree_int_cst_lt (value2, (*l)->low))
4196 *duplicate = (*l)->code_label;
4201 /* Add this label to the chain, and succeed.
4202 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4203 obstack and will thus survive till the end of the case statement. */
4205 n = (struct case_node *) oballoc (sizeof (struct case_node));
4208 n->low = copy_node (value1);
4209 n->high = copy_node (value2);
4210 n->code_label = label;
4213 expand_label (label);
4215 case_stack->data.case_stmt.num_ranges++;
4221 /* Accumulate one case or default label; VALUE is the value of the
4222 case, or nil for a default label. If not currently inside a case,
4223 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4224 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4225 Return 0 on success. This function is a leftover from the earlier
4226 bytecode compiler, which was based on gcc 1.37. It should be
4227 merged into pushcase. */
4230 bc_pushcase (value, label)
4234 struct nesting *thiscase = case_stack;
4235 struct case_node *case_label, *new_label;
4240 /* Fail if duplicate, overlap, or out of type range. */
4243 value = convert (thiscase->data.case_stmt.nominal_type, value);
4244 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4247 for (case_label = thiscase->data.case_stmt.case_list;
4248 case_label->left; case_label = case_label->left)
4249 if (! tree_int_cst_lt (case_label->left->high, value))
4252 if (case_label != thiscase->data.case_stmt.case_list
4253 && ! tree_int_cst_lt (case_label->high, value)
4254 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4257 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4258 new_label->low = new_label->high = copy_node (value);
4259 new_label->code_label = label;
4260 new_label->left = case_label->left;
4262 case_label->left = new_label;
4263 thiscase->data.case_stmt.num_ranges++;
4267 if (thiscase->data.case_stmt.default_label)
4269 thiscase->data.case_stmt.default_label = label;
4272 expand_label (label);
4276 /* Returns the number of possible values of TYPE.
4277 Returns -1 if the number is unknown or variable.
4278 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4279 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4280 do not increase monotonically (there may be duplicates);
4281 to 1 if the values increase monotonically, but not always by 1;
4282 otherwise sets it to 0. */
4285 all_cases_count (type, spareness)
4289 HOST_WIDE_INT count, count_high = 0;
4292 switch (TREE_CODE (type))
4299 count = 1 << BITS_PER_UNIT;
4303 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4304 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4309 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4310 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4311 but with overflow checking. */
4312 tree mint = TYPE_MIN_VALUE (type);
4313 tree maxt = TYPE_MAX_VALUE (type);
4314 HOST_WIDE_INT lo, hi;
4315 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4317 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4319 add_double (lo, hi, 1, 0, &lo, &hi);
4320 if (hi != 0 || lo < 0)
4327 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4329 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4330 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4331 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4332 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4336 if (*spareness == 1)
4338 tree prev = TREE_VALUE (TYPE_VALUES (type));
4339 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4341 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4346 prev = TREE_VALUE (t);
4355 #define BITARRAY_TEST(ARRAY, INDEX) \
4356 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4357 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4358 #define BITARRAY_SET(ARRAY, INDEX) \
4359 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4360 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4362 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4363 with the case values we have seen, assuming the case expression
4365 SPARSENESS is as determined by all_cases_count.
4367 The time needed is proportional to COUNT, unless
4368 SPARSENESS is 2, in which case quadratic time is needed. */
4371 mark_seen_cases (type, cases_seen, count, sparseness)
4373 unsigned char *cases_seen;
4379 tree next_node_to_try = NULL_TREE;
4380 long next_node_offset = 0;
4382 register struct case_node *n;
4383 tree val = make_node (INTEGER_CST);
4384 TREE_TYPE (val) = type;
4385 for (n = case_stack->data.case_stmt.case_list; n;
4388 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4389 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4390 while ( ! tree_int_cst_lt (n->high, val))
4392 /* Calculate (into xlo) the "offset" of the integer (val).
4393 The element with lowest value has offset 0, the next smallest
4394 element has offset 1, etc. */
4396 HOST_WIDE_INT xlo, xhi;
4398 if (sparseness == 2)
4400 /* This less efficient loop is only needed to handle
4401 duplicate case values (multiple enum constants
4402 with the same value). */
4403 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4404 t = TREE_CHAIN (t), xlo++)
4406 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4407 BITARRAY_SET (cases_seen, xlo);
4412 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4414 /* The TYPE_VALUES will be in increasing order, so
4415 starting searching where we last ended. */
4416 t = next_node_to_try;
4417 xlo = next_node_offset;
4423 t = TYPE_VALUES (type);
4426 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4428 next_node_to_try = TREE_CHAIN (t);
4429 next_node_offset = xlo + 1;
4434 if (t == next_node_to_try)
4440 t = TYPE_MIN_VALUE (type);
4442 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4446 add_double (xlo, xhi,
4447 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4451 if (xhi == 0 && xlo >= 0 && xlo < count)
4452 BITARRAY_SET (cases_seen, xlo);
4454 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4456 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4461 /* Called when the index of a switch statement is an enumerated type
4462 and there is no default label.
4464 Checks that all enumeration literals are covered by the case
4465 expressions of a switch. Also, warn if there are any extra
4466 switch cases that are *not* elements of the enumerated type.
4468 If all enumeration literals were covered by the case expressions,
4469 turn one of the expressions into the default expression since it should
4470 not be possible to fall through such a switch. */
4473 check_for_full_enumeration_handling (type)
4476 register struct case_node *n;
4477 register struct case_node **l;
4478 register tree chain;
4481 /* True iff the selector type is a numbered set mode. */
4484 /* The number of possible selector values. */
4487 /* For each possible selector value. a one iff it has been matched
4488 by a case value alternative. */
4489 unsigned char *cases_seen;
4491 /* The allocated size of cases_seen, in chars. */
4495 if (output_bytecode)
4497 bc_check_for_full_enumeration_handling (type);
4504 size = all_cases_count (type, &sparseness);
4505 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4507 if (size > 0 && size < 600000
4508 /* We deliberately use malloc here - not xmalloc. */
4509 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4512 tree v = TYPE_VALUES (type);
4513 bzero (cases_seen, bytes_needed);
4515 /* The time complexity of this code is normally O(N), where
4516 N being the number of members in the enumerated type.
4517 However, if type is a ENUMERAL_TYPE whose values do not
4518 increase monotonically, quadratic time may be needed. */
4520 mark_seen_cases (type, cases_seen, size, sparseness);
4522 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4524 if (BITARRAY_TEST(cases_seen, i) == 0)
4525 warning ("enumeration value `%s' not handled in switch",
4526 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4532 /* Now we go the other way around; we warn if there are case
4533 expressions that don't correspond to enumerators. This can
4534 occur since C and C++ don't enforce type-checking of
4535 assignments to enumeration variables. */
4538 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4540 for (chain = TYPE_VALUES (type);
4541 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4542 chain = TREE_CHAIN (chain))
4547 if (TYPE_NAME (type) == 0)
4548 warning ("case value `%d' not in enumerated type",
4549 TREE_INT_CST_LOW (n->low));
4551 warning ("case value `%d' not in enumerated type `%s'",
4552 TREE_INT_CST_LOW (n->low),
4553 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4556 : DECL_NAME (TYPE_NAME (type))));
4558 if (!tree_int_cst_equal (n->low, n->high))
4560 for (chain = TYPE_VALUES (type);
4561 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4562 chain = TREE_CHAIN (chain))
4567 if (TYPE_NAME (type) == 0)
4568 warning ("case value `%d' not in enumerated type",
4569 TREE_INT_CST_LOW (n->high));
4571 warning ("case value `%d' not in enumerated type `%s'",
4572 TREE_INT_CST_LOW (n->high),
4573 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4576 : DECL_NAME (TYPE_NAME (type))));
4582 /* ??? This optimization is disabled because it causes valid programs to
4583 fail. ANSI C does not guarantee that an expression with enum type
4584 will have a value that is the same as one of the enumeration literals. */
4586 /* If all values were found as case labels, make one of them the default
4587 label. Thus, this switch will never fall through. We arbitrarily pick
4588 the last one to make the default since this is likely the most
4589 efficient choice. */
4593 for (l = &case_stack->data.case_stmt.case_list;
4598 case_stack->data.case_stmt.default_label = (*l)->code_label;
4605 /* Check that all enumeration literals are covered by the case
4606 expressions of a switch. Also warn if there are any cases
4607 that are not elements of the enumerated type. */
4610 bc_check_for_full_enumeration_handling (type)
4613 struct nesting *thiscase = case_stack;
4614 struct case_node *c;
4617 /* Check for enums not handled. */
4618 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4620 for (c = thiscase->data.case_stmt.case_list->left;
4621 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4624 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4625 warning ("enumerated value `%s' not handled in switch",
4626 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4629 /* Check for cases not in the enumeration. */
4630 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4632 for (e = TYPE_VALUES (type);
4633 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4637 warning ("case value `%d' not in enumerated type `%s'",
4638 TREE_INT_CST_LOW (c->low),
4639 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4641 : DECL_NAME (TYPE_NAME (type))));
4645 /* Terminate a case (Pascal) or switch (C) statement
4646 in which ORIG_INDEX is the expression to be tested.
4647 Generate the code to test it and jump to the right place. */
4650 expand_end_case (orig_index)
4653 tree minval, maxval, range, orig_minval;
4654 rtx default_label = 0;
4655 register struct case_node *n;
4663 register struct nesting *thiscase = case_stack;
4664 tree index_expr, index_type;
4667 if (output_bytecode)
4669 bc_expand_end_case (orig_index);
4673 table_label = gen_label_rtx ();
4674 index_expr = thiscase->data.case_stmt.index_expr;
4675 index_type = TREE_TYPE (index_expr);
4676 unsignedp = TREE_UNSIGNED (index_type);
4678 do_pending_stack_adjust ();
4680 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4681 if (index_type != error_mark_node)
4683 /* If switch expression was an enumerated type, check that all
4684 enumeration literals are covered by the cases.
4685 No sense trying this if there's a default case, however. */
4687 if (!thiscase->data.case_stmt.default_label
4688 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4689 && TREE_CODE (index_expr) != INTEGER_CST)
4690 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4692 /* If this is the first label, warn if any insns have been emitted. */
4693 if (thiscase->data.case_stmt.seenlabel == 0)
4696 for (insn = get_last_insn ();
4697 insn != case_stack->data.case_stmt.start;
4698 insn = PREV_INSN (insn))
4699 if (GET_CODE (insn) != NOTE
4700 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4702 warning ("unreachable code at beginning of %s",
4703 case_stack->data.case_stmt.printname);
4708 /* If we don't have a default-label, create one here,
4709 after the body of the switch. */
4710 if (thiscase->data.case_stmt.default_label == 0)
4712 thiscase->data.case_stmt.default_label
4713 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4714 expand_label (thiscase->data.case_stmt.default_label);
4716 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4718 before_case = get_last_insn ();
4720 /* Simplify the case-list before we count it. */
4721 group_case_nodes (thiscase->data.case_stmt.case_list);
4723 /* Get upper and lower bounds of case values.
4724 Also convert all the case values to the index expr's data type. */
4727 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4729 /* Check low and high label values are integers. */
4730 if (TREE_CODE (n->low) != INTEGER_CST)
4732 if (TREE_CODE (n->high) != INTEGER_CST)
4735 n->low = convert (index_type, n->low);
4736 n->high = convert (index_type, n->high);
4738 /* Count the elements and track the largest and smallest
4739 of them (treating them as signed even if they are not). */
4747 if (INT_CST_LT (n->low, minval))
4749 if (INT_CST_LT (maxval, n->high))
4752 /* A range counts double, since it requires two compares. */
4753 if (! tree_int_cst_equal (n->low, n->high))
4757 orig_minval = minval;
4759 /* Compute span of values. */
4761 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4765 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4767 emit_jump (default_label);
4770 /* If range of values is much bigger than number of values,
4771 make a sequence of conditional branches instead of a dispatch.
4772 If the switch-index is a constant, do it this way
4773 because we can optimize it. */
4775 #ifndef CASE_VALUES_THRESHOLD
4777 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4779 /* If machine does not have a case insn that compares the
4780 bounds, this means extra overhead for dispatch tables
4781 which raises the threshold for using them. */
4782 #define CASE_VALUES_THRESHOLD 5
4783 #endif /* HAVE_casesi */
4784 #endif /* CASE_VALUES_THRESHOLD */
4786 else if (TREE_INT_CST_HIGH (range) != 0
4787 || count < CASE_VALUES_THRESHOLD
4788 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4790 || TREE_CODE (index_expr) == INTEGER_CST
4791 /* These will reduce to a constant. */
4792 || (TREE_CODE (index_expr) == CALL_EXPR
4793 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4794 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4795 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4796 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4797 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4799 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4801 /* If the index is a short or char that we do not have
4802 an insn to handle comparisons directly, convert it to
4803 a full integer now, rather than letting each comparison
4804 generate the conversion. */
4806 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4807 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4808 == CODE_FOR_nothing))
4810 enum machine_mode wider_mode;
4811 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4812 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4813 if (cmp_optab->handlers[(int) wider_mode].insn_code
4814 != CODE_FOR_nothing)
4816 index = convert_to_mode (wider_mode, index, unsignedp);
4822 do_pending_stack_adjust ();
4824 index = protect_from_queue (index, 0);
4825 if (GET_CODE (index) == MEM)
4826 index = copy_to_reg (index);
4827 if (GET_CODE (index) == CONST_INT
4828 || TREE_CODE (index_expr) == INTEGER_CST)
4830 /* Make a tree node with the proper constant value
4831 if we don't already have one. */
4832 if (TREE_CODE (index_expr) != INTEGER_CST)
4835 = build_int_2 (INTVAL (index),
4836 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4837 index_expr = convert (index_type, index_expr);
4840 /* For constant index expressions we need only
4841 issue a unconditional branch to the appropriate
4842 target code. The job of removing any unreachable
4843 code is left to the optimisation phase if the
4844 "-O" option is specified. */
4845 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4846 if (! tree_int_cst_lt (index_expr, n->low)
4847 && ! tree_int_cst_lt (n->high, index_expr))
4851 emit_jump (label_rtx (n->code_label));
4853 emit_jump (default_label);
4857 /* If the index expression is not constant we generate
4858 a binary decision tree to select the appropriate
4859 target code. This is done as follows:
4861 The list of cases is rearranged into a binary tree,
4862 nearly optimal assuming equal probability for each case.
4864 The tree is transformed into RTL, eliminating
4865 redundant test conditions at the same time.
4867 If program flow could reach the end of the
4868 decision tree an unconditional jump to the
4869 default code is emitted. */
4872 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4873 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4874 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4876 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4877 default_label, index_type);
4878 emit_jump_if_reachable (default_label);
4887 enum machine_mode index_mode = SImode;
4888 int index_bits = GET_MODE_BITSIZE (index_mode);
4890 enum machine_mode op_mode;
4892 /* Convert the index to SImode. */
4893 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4894 > GET_MODE_BITSIZE (index_mode))
4896 enum machine_mode omode = TYPE_MODE (index_type);
4897 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4899 /* We must handle the endpoints in the original mode. */
4900 index_expr = build (MINUS_EXPR, index_type,
4901 index_expr, minval);
4902 minval = integer_zero_node;
4903 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4904 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4905 emit_jump_insn (gen_bltu (default_label));
4906 /* Now we can safely truncate. */
4907 index = convert_to_mode (index_mode, index, 0);
4911 if (TYPE_MODE (index_type) != index_mode)
4913 index_expr = convert (type_for_size (index_bits, 0),
4915 index_type = TREE_TYPE (index_expr);
4918 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4921 index = protect_from_queue (index, 0);
4922 do_pending_stack_adjust ();
4924 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4925 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4927 index = copy_to_mode_reg (op_mode, index);
4929 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4931 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4932 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4934 op1 = copy_to_mode_reg (op_mode, op1);
4936 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4938 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4939 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4941 op2 = copy_to_mode_reg (op_mode, op2);
4943 emit_jump_insn (gen_casesi (index, op1, op2,
4944 table_label, default_label));
4948 #ifdef HAVE_tablejump
4949 if (! win && HAVE_tablejump)
4951 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4952 fold (build (MINUS_EXPR, index_type,
4953 index_expr, minval)));
4954 index_type = TREE_TYPE (index_expr);
4955 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4957 index = protect_from_queue (index, 0);
4958 do_pending_stack_adjust ();
4960 do_tablejump (index, TYPE_MODE (index_type),
4961 expand_expr (range, NULL_RTX, VOIDmode, 0),
4962 table_label, default_label);
4969 /* Get table of labels to jump to, in order of case index. */
4971 ncases = TREE_INT_CST_LOW (range) + 1;
4972 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4973 bzero ((char *) labelvec, ncases * sizeof (rtx));
4975 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4977 register HOST_WIDE_INT i
4978 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4983 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4984 if (i + TREE_INT_CST_LOW (orig_minval)
4985 == TREE_INT_CST_LOW (n->high))
4991 /* Fill in the gaps with the default. */
4992 for (i = 0; i < ncases; i++)
4993 if (labelvec[i] == 0)
4994 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
4996 /* Output the table */
4997 emit_label (table_label);
4999 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
5000 were an expression, instead of an #ifdef/#ifndef. */
5002 #ifdef CASE_VECTOR_PC_RELATIVE
5006 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
5007 gen_rtx (LABEL_REF, Pmode, table_label),
5008 gen_rtvec_v (ncases, labelvec)));
5010 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
5011 gen_rtvec_v (ncases, labelvec)));
5013 /* If the case insn drops through the table,
5014 after the table we must jump to the default-label.
5015 Otherwise record no drop-through after the table. */
5016 #ifdef CASE_DROPS_THROUGH
5017 emit_jump (default_label);
5023 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5024 reorder_insns (before_case, get_last_insn (),
5025 thiscase->data.case_stmt.start);
5028 if (thiscase->exit_label)
5029 emit_label (thiscase->exit_label);
5031 POPSTACK (case_stack);
5037 /* Terminate a case statement. EXPR is the original index
5041 bc_expand_end_case (expr)
5044 struct nesting *thiscase = case_stack;
5045 enum bytecode_opcode opcode;
5046 struct bc_label *jump_label;
5047 struct case_node *c;
5049 bc_emit_bytecode (jump);
5050 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5052 #ifdef DEBUG_PRINT_CODE
5053 fputc ('\n', stderr);
5056 /* Now that the size of the jump table is known, emit the actual
5057 indexed jump instruction. */
5058 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5060 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5061 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5062 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5064 bc_emit_bytecode (opcode);
5066 /* Now emit the case instructions literal arguments, in order.
5067 In addition to the value on the stack, it uses:
5068 1. The address of the jump table.
5069 2. The size of the jump table.
5070 3. The default label. */
5072 jump_label = bc_get_bytecode_label ();
5073 bc_emit_bytecode_labelref (jump_label);
5074 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5075 sizeof thiscase->data.case_stmt.num_ranges);
5077 if (thiscase->data.case_stmt.default_label)
5078 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5080 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5082 /* Output the jump table. */
5084 bc_align_bytecode (3 /* PTR_ALIGN */);
5085 bc_emit_bytecode_labeldef (jump_label);
5087 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5088 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5090 opcode = TREE_INT_CST_LOW (c->low);
5091 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5093 opcode = TREE_INT_CST_LOW (c->high);
5094 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5096 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5099 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5100 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5102 bc_emit_bytecode_DI_const (c->low);
5103 bc_emit_bytecode_DI_const (c->high);
5105 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5112 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5114 /* Possibly issue enumeration warnings. */
5116 if (!thiscase->data.case_stmt.default_label
5117 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5118 && TREE_CODE (expr) != INTEGER_CST
5120 check_for_full_enumeration_handling (TREE_TYPE (expr));
5123 #ifdef DEBUG_PRINT_CODE
5124 fputc ('\n', stderr);
5127 POPSTACK (case_stack);
5131 /* Return unique bytecode ID. */
5136 static int bc_uid = 0;
5141 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5144 do_jump_if_equal (op1, op2, label, unsignedp)
5145 rtx op1, op2, label;
5148 if (GET_CODE (op1) == CONST_INT
5149 && GET_CODE (op2) == CONST_INT)
5151 if (INTVAL (op1) == INTVAL (op2))
5156 enum machine_mode mode = GET_MODE (op1);
5157 if (mode == VOIDmode)
5158 mode = GET_MODE (op2);
5159 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5160 emit_jump_insn (gen_beq (label));
5164 /* Not all case values are encountered equally. This function
5165 uses a heuristic to weight case labels, in cases where that
5166 looks like a reasonable thing to do.
5168 Right now, all we try to guess is text, and we establish the
5171 chars above space: 16
5180 If we find any cases in the switch that are not either -1 or in the range
5181 of valid ASCII characters, or are control characters other than those
5182 commonly used with "\", don't treat this switch scanning text.
5184 Return 1 if these nodes are suitable for cost estimation, otherwise
5188 estimate_case_costs (node)
5191 tree min_ascii = build_int_2 (-1, -1);
5192 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5196 /* If we haven't already made the cost table, make it now. Note that the
5197 lower bound of the table is -1, not zero. */
5199 if (cost_table == NULL)
5201 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5202 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5204 for (i = 0; i < 128; i++)
5208 else if (ispunct (i))
5210 else if (iscntrl (i))
5214 cost_table[' '] = 8;
5215 cost_table['\t'] = 4;
5216 cost_table['\0'] = 4;
5217 cost_table['\n'] = 2;
5218 cost_table['\f'] = 1;
5219 cost_table['\v'] = 1;
5220 cost_table['\b'] = 1;
5223 /* See if all the case expressions look like text. It is text if the
5224 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5225 as signed arithmetic since we don't want to ever access cost_table with a
5226 value less than -1. Also check that none of the constants in a range
5227 are strange control characters. */
5229 for (n = node; n; n = n->right)
5231 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5234 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5235 if (cost_table[i] < 0)
5239 /* All interesting values are within the range of interesting
5240 ASCII characters. */
5244 /* Scan an ordered list of case nodes
5245 combining those with consecutive values or ranges.
5247 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5250 group_case_nodes (head)
5253 case_node_ptr node = head;
5257 rtx lb = next_real_insn (label_rtx (node->code_label));
5258 case_node_ptr np = node;
5260 /* Try to group the successors of NODE with NODE. */
5261 while (((np = np->right) != 0)
5262 /* Do they jump to the same place? */
5263 && next_real_insn (label_rtx (np->code_label)) == lb
5264 /* Are their ranges consecutive? */
5265 && tree_int_cst_equal (np->low,
5266 fold (build (PLUS_EXPR,
5267 TREE_TYPE (node->high),
5270 /* An overflow is not consecutive. */
5271 && tree_int_cst_lt (node->high,
5272 fold (build (PLUS_EXPR,
5273 TREE_TYPE (node->high),
5275 integer_one_node))))
5277 node->high = np->high;
5279 /* NP is the first node after NODE which can't be grouped with it.
5280 Delete the nodes in between, and move on to that node. */
5286 /* Take an ordered list of case nodes
5287 and transform them into a near optimal binary tree,
5288 on the assumption that any target code selection value is as
5289 likely as any other.
5291 The transformation is performed by splitting the ordered
5292 list into two equal sections plus a pivot. The parts are
5293 then attached to the pivot as left and right branches. Each
5294 branch is is then transformed recursively. */
5297 balance_case_nodes (head, parent)
5298 case_node_ptr *head;
5299 case_node_ptr parent;
5301 register case_node_ptr np;
5309 register case_node_ptr *npp;
5312 /* Count the number of entries on branch. Also count the ranges. */
5316 if (!tree_int_cst_equal (np->low, np->high))
5320 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5324 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5332 /* Split this list if it is long enough for that to help. */
5337 /* Find the place in the list that bisects the list's total cost,
5338 Here I gets half the total cost. */
5343 /* Skip nodes while their cost does not reach that amount. */
5344 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5345 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5346 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5349 npp = &(*npp)->right;
5354 /* Leave this branch lopsided, but optimize left-hand
5355 side and fill in `parent' fields for right-hand side. */
5357 np->parent = parent;
5358 balance_case_nodes (&np->left, np);
5359 for (; np->right; np = np->right)
5360 np->right->parent = np;
5364 /* If there are just three nodes, split at the middle one. */
5366 npp = &(*npp)->right;
5369 /* Find the place in the list that bisects the list's total cost,
5370 where ranges count as 2.
5371 Here I gets half the total cost. */
5372 i = (i + ranges + 1) / 2;
5375 /* Skip nodes while their cost does not reach that amount. */
5376 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5381 npp = &(*npp)->right;
5386 np->parent = parent;
5389 /* Optimize each of the two split parts. */
5390 balance_case_nodes (&np->left, np);
5391 balance_case_nodes (&np->right, np);
5395 /* Else leave this branch as one level,
5396 but fill in `parent' fields. */
5398 np->parent = parent;
5399 for (; np->right; np = np->right)
5400 np->right->parent = np;
5405 /* Search the parent sections of the case node tree
5406 to see if a test for the lower bound of NODE would be redundant.
5407 INDEX_TYPE is the type of the index expression.
5409 The instructions to generate the case decision tree are
5410 output in the same order as nodes are processed so it is
5411 known that if a parent node checks the range of the current
5412 node minus one that the current node is bounded at its lower
5413 span. Thus the test would be redundant. */
5416 node_has_low_bound (node, index_type)
5421 case_node_ptr pnode;
5423 /* If the lower bound of this node is the lowest value in the index type,
5424 we need not test it. */
5426 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5429 /* If this node has a left branch, the value at the left must be less
5430 than that at this node, so it cannot be bounded at the bottom and
5431 we need not bother testing any further. */
5436 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5437 node->low, integer_one_node));
5439 /* If the subtraction above overflowed, we can't verify anything.
5440 Otherwise, look for a parent that tests our value - 1. */
5442 if (! tree_int_cst_lt (low_minus_one, node->low))
5445 for (pnode = node->parent; pnode; pnode = pnode->parent)
5446 if (tree_int_cst_equal (low_minus_one, pnode->high))
5452 /* Search the parent sections of the case node tree
5453 to see if a test for the upper bound of NODE would be redundant.
5454 INDEX_TYPE is the type of the index expression.
5456 The instructions to generate the case decision tree are
5457 output in the same order as nodes are processed so it is
5458 known that if a parent node checks the range of the current
5459 node plus one that the current node is bounded at its upper
5460 span. Thus the test would be redundant. */
5463 node_has_high_bound (node, index_type)
5468 case_node_ptr pnode;
5470 /* If the upper bound of this node is the highest value in the type
5471 of the index expression, we need not test against it. */
5473 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5476 /* If this node has a right branch, the value at the right must be greater
5477 than that at this node, so it cannot be bounded at the top and
5478 we need not bother testing any further. */
5483 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5484 node->high, integer_one_node));
5486 /* If the addition above overflowed, we can't verify anything.
5487 Otherwise, look for a parent that tests our value + 1. */
5489 if (! tree_int_cst_lt (node->high, high_plus_one))
5492 for (pnode = node->parent; pnode; pnode = pnode->parent)
5493 if (tree_int_cst_equal (high_plus_one, pnode->low))
5499 /* Search the parent sections of the
5500 case node tree to see if both tests for the upper and lower
5501 bounds of NODE would be redundant. */
5504 node_is_bounded (node, index_type)
5508 return (node_has_low_bound (node, index_type)
5509 && node_has_high_bound (node, index_type));
5512 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5515 emit_jump_if_reachable (label)
5518 if (GET_CODE (get_last_insn ()) != BARRIER)
5522 /* Emit step-by-step code to select a case for the value of INDEX.
5523 The thus generated decision tree follows the form of the
5524 case-node binary tree NODE, whose nodes represent test conditions.
5525 INDEX_TYPE is the type of the index of the switch.
5527 Care is taken to prune redundant tests from the decision tree
5528 by detecting any boundary conditions already checked by
5529 emitted rtx. (See node_has_high_bound, node_has_low_bound
5530 and node_is_bounded, above.)
5532 Where the test conditions can be shown to be redundant we emit
5533 an unconditional jump to the target code. As a further
5534 optimization, the subordinates of a tree node are examined to
5535 check for bounded nodes. In this case conditional and/or
5536 unconditional jumps as a result of the boundary check for the
5537 current node are arranged to target the subordinates associated
5538 code for out of bound conditions on the current node node.
5540 We can assume that when control reaches the code generated here,
5541 the index value has already been compared with the parents
5542 of this node, and determined to be on the same side of each parent
5543 as this node is. Thus, if this node tests for the value 51,
5544 and a parent tested for 52, we don't need to consider
5545 the possibility of a value greater than 51. If another parent
5546 tests for the value 50, then this node need not test anything. */
5549 emit_case_nodes (index, node, default_label, index_type)
5555 /* If INDEX has an unsigned type, we must make unsigned branches. */
5556 int unsignedp = TREE_UNSIGNED (index_type);
5557 typedef rtx rtx_function ();
5558 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5559 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5560 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5561 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5562 enum machine_mode mode = GET_MODE (index);
5564 /* See if our parents have already tested everything for us.
5565 If they have, emit an unconditional jump for this node. */
5566 if (node_is_bounded (node, index_type))
5567 emit_jump (label_rtx (node->code_label));
5569 else if (tree_int_cst_equal (node->low, node->high))
5571 /* Node is single valued. First see if the index expression matches
5572 this node and then check our children, if any. */
5574 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5575 label_rtx (node->code_label), unsignedp);
5577 if (node->right != 0 && node->left != 0)
5579 /* This node has children on both sides.
5580 Dispatch to one side or the other
5581 by comparing the index value with this node's value.
5582 If one subtree is bounded, check that one first,
5583 so we can avoid real branches in the tree. */
5585 if (node_is_bounded (node->right, index_type))
5587 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5589 GT, NULL_RTX, mode, unsignedp, 0);
5591 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5592 emit_case_nodes (index, node->left, default_label, index_type);
5595 else if (node_is_bounded (node->left, index_type))
5597 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5599 LT, NULL_RTX, mode, unsignedp, 0);
5600 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5601 emit_case_nodes (index, node->right, default_label, index_type);
5606 /* Neither node is bounded. First distinguish the two sides;
5607 then emit the code for one side at a time. */
5610 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5612 /* See if the value is on the right. */
5613 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5615 GT, NULL_RTX, mode, unsignedp, 0);
5616 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5618 /* Value must be on the left.
5619 Handle the left-hand subtree. */
5620 emit_case_nodes (index, node->left, default_label, index_type);
5621 /* If left-hand subtree does nothing,
5623 emit_jump_if_reachable (default_label);
5625 /* Code branches here for the right-hand subtree. */
5626 expand_label (test_label);
5627 emit_case_nodes (index, node->right, default_label, index_type);
5631 else if (node->right != 0 && node->left == 0)
5633 /* Here we have a right child but no left so we issue conditional
5634 branch to default and process the right child.
5636 Omit the conditional branch to default if we it avoid only one
5637 right child; it costs too much space to save so little time. */
5639 if (node->right->right || node->right->left
5640 || !tree_int_cst_equal (node->right->low, node->right->high))
5642 if (!node_has_low_bound (node, index_type))
5644 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5646 LT, NULL_RTX, mode, unsignedp, 0);
5647 emit_jump_insn ((*gen_blt_pat) (default_label));
5650 emit_case_nodes (index, node->right, default_label, index_type);
5653 /* We cannot process node->right normally
5654 since we haven't ruled out the numbers less than
5655 this node's value. So handle node->right explicitly. */
5656 do_jump_if_equal (index,
5657 expand_expr (node->right->low, NULL_RTX,
5659 label_rtx (node->right->code_label), unsignedp);
5662 else if (node->right == 0 && node->left != 0)
5664 /* Just one subtree, on the left. */
5666 #if 0 /* The following code and comment were formerly part
5667 of the condition here, but they didn't work
5668 and I don't understand what the idea was. -- rms. */
5669 /* If our "most probable entry" is less probable
5670 than the default label, emit a jump to
5671 the default label using condition codes
5672 already lying around. With no right branch,
5673 a branch-greater-than will get us to the default
5676 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5679 if (node->left->left || node->left->right
5680 || !tree_int_cst_equal (node->left->low, node->left->high))
5682 if (!node_has_high_bound (node, index_type))
5684 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5686 GT, NULL_RTX, mode, unsignedp, 0);
5687 emit_jump_insn ((*gen_bgt_pat) (default_label));
5690 emit_case_nodes (index, node->left, default_label, index_type);
5693 /* We cannot process node->left normally
5694 since we haven't ruled out the numbers less than
5695 this node's value. So handle node->left explicitly. */
5696 do_jump_if_equal (index,
5697 expand_expr (node->left->low, NULL_RTX,
5699 label_rtx (node->left->code_label), unsignedp);
5704 /* Node is a range. These cases are very similar to those for a single
5705 value, except that we do not start by testing whether this node
5706 is the one to branch to. */
5708 if (node->right != 0 && node->left != 0)
5710 /* Node has subtrees on both sides.
5711 If the right-hand subtree is bounded,
5712 test for it first, since we can go straight there.
5713 Otherwise, we need to make a branch in the control structure,
5714 then handle the two subtrees. */
5715 tree test_label = 0;
5717 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5719 GT, NULL_RTX, mode, unsignedp, 0);
5721 if (node_is_bounded (node->right, index_type))
5722 /* Right hand node is fully bounded so we can eliminate any
5723 testing and branch directly to the target code. */
5724 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5727 /* Right hand node requires testing.
5728 Branch to a label where we will handle it later. */
5730 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5731 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5734 /* Value belongs to this node or to the left-hand subtree. */
5736 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5737 GE, NULL_RTX, mode, unsignedp, 0);
5738 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5740 /* Handle the left-hand subtree. */
5741 emit_case_nodes (index, node->left, default_label, index_type);
5743 /* If right node had to be handled later, do that now. */
5747 /* If the left-hand subtree fell through,
5748 don't let it fall into the right-hand subtree. */
5749 emit_jump_if_reachable (default_label);
5751 expand_label (test_label);
5752 emit_case_nodes (index, node->right, default_label, index_type);
5756 else if (node->right != 0 && node->left == 0)
5758 /* Deal with values to the left of this node,
5759 if they are possible. */
5760 if (!node_has_low_bound (node, index_type))
5762 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5764 LT, NULL_RTX, mode, unsignedp, 0);
5765 emit_jump_insn ((*gen_blt_pat) (default_label));
5768 /* Value belongs to this node or to the right-hand subtree. */
5770 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5772 LE, NULL_RTX, mode, unsignedp, 0);
5773 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5775 emit_case_nodes (index, node->right, default_label, index_type);
5778 else if (node->right == 0 && node->left != 0)
5780 /* Deal with values to the right of this node,
5781 if they are possible. */
5782 if (!node_has_high_bound (node, index_type))
5784 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5786 GT, NULL_RTX, mode, unsignedp, 0);
5787 emit_jump_insn ((*gen_bgt_pat) (default_label));
5790 /* Value belongs to this node or to the left-hand subtree. */
5792 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5793 GE, NULL_RTX, mode, unsignedp, 0);
5794 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5796 emit_case_nodes (index, node->left, default_label, index_type);
5801 /* Node has no children so we check low and high bounds to remove
5802 redundant tests. Only one of the bounds can exist,
5803 since otherwise this node is bounded--a case tested already. */
5805 if (!node_has_high_bound (node, index_type))
5807 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5809 GT, NULL_RTX, mode, unsignedp, 0);
5810 emit_jump_insn ((*gen_bgt_pat) (default_label));
5813 if (!node_has_low_bound (node, index_type))
5815 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5817 LT, NULL_RTX, mode, unsignedp, 0);
5818 emit_jump_insn ((*gen_blt_pat) (default_label));
5821 emit_jump (label_rtx (node->code_label));
5826 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5827 so that the debugging info will be correct for the unrolled loop. */
5829 /* Indexed by block number, contains a pointer to the N'th block node. */
5831 static tree *block_vector;
5834 find_loop_tree_blocks ()
5836 tree block = DECL_INITIAL (current_function_decl);
5838 /* There first block is for the function body, and does not have
5839 corresponding block notes. Don't include it in the block vector. */
5840 block = BLOCK_SUBBLOCKS (block);
5842 block_vector = identify_blocks (block, get_insns ());
5846 unroll_block_trees ()
5848 tree block = DECL_INITIAL (current_function_decl);
5850 reorder_blocks (block_vector, block, get_insns ());