1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-5, 1996 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, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
56 #include "bc-typecd.h"
57 #include "bc-opcode.h"
61 #define obstack_chunk_alloc xmalloc
62 #define obstack_chunk_free free
63 struct obstack stmt_obstack;
65 /* Filename and line number of last line-number note,
66 whether we actually emitted it or not. */
70 /* Nonzero if within a ({...}) grouping, in which case we must
71 always compute a value for each expr-stmt in case it is the last one. */
73 int expr_stmts_for_value;
75 /* Each time we expand an expression-statement,
76 record the expr's type and its RTL value here. */
78 static tree last_expr_type;
79 static rtx last_expr_value;
81 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
82 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
83 This is used by the `remember_end_note' function to record the endpoint
84 of each generated block in its associated BLOCK node. */
86 static rtx last_block_end_note;
88 /* Number of binding contours started so far in this function. */
90 int block_start_count;
92 /* Nonzero if function being compiled needs to
93 return the address of where it has put a structure value. */
95 extern int current_function_returns_pcc_struct;
97 /* Label that will go on parm cleanup code, if any.
98 Jumping to this label runs cleanup code for parameters, if
99 such code must be run. Following this code is the logical return label. */
101 extern rtx cleanup_label;
103 /* Label that will go on function epilogue.
104 Jumping to this label serves as a "return" instruction
105 on machines which require execution of the epilogue on all returns. */
107 extern rtx return_label;
109 /* Offset to end of allocated area of stack frame.
110 If stack grows down, this is the address of the last stack slot allocated.
111 If stack grows up, this is the address for the next slot. */
112 extern int frame_offset;
114 /* Label to jump back to for tail recursion, or 0 if we have
115 not yet needed one for this function. */
116 extern rtx tail_recursion_label;
118 /* Place after which to insert the tail_recursion_label if we need one. */
119 extern rtx tail_recursion_reentry;
121 /* Location at which to save the argument pointer if it will need to be
122 referenced. There are two cases where this is done: if nonlocal gotos
123 exist, or if vars whose is an offset from the argument pointer will be
124 needed by inner routines. */
126 extern rtx arg_pointer_save_area;
128 /* Chain of all RTL_EXPRs that have insns in them. */
129 extern tree rtl_expr_chain;
131 #if 0 /* Turned off because 0 seems to work just as well. */
132 /* Cleanup lists are required for binding levels regardless of whether
133 that binding level has cleanups or not. This node serves as the
134 cleanup list whenever an empty list is required. */
135 static tree empty_cleanup_list;
138 extern void (*interim_eh_hook) PROTO((tree));
140 /* Functions and data structures for expanding case statements. */
142 /* Case label structure, used to hold info on labels within case
143 statements. We handle "range" labels; for a single-value label
144 as in C, the high and low limits are the same.
146 A chain of case nodes is initially maintained via the RIGHT fields
147 in the nodes. Nodes with higher case values are later in the list.
149 Switch statements can be output in one of two forms. A branch table
150 is used if there are more than a few labels and the labels are dense
151 within the range between the smallest and largest case value. If a
152 branch table is used, no further manipulations are done with the case
155 The alternative to the use of a branch table is to generate a series
156 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
157 and PARENT fields to hold a binary tree. Initially the tree is
158 totally unbalanced, with everything on the right. We balance the tree
159 with nodes on the left having lower case values than the parent
160 and nodes on the right having higher values. We then output the tree
165 struct case_node *left; /* Left son in binary tree */
166 struct case_node *right; /* Right son in binary tree; also node chain */
167 struct case_node *parent; /* Parent of node in binary tree */
168 tree low; /* Lowest index value for this label */
169 tree high; /* Highest index value for this label */
170 tree code_label; /* Label to jump to when node matches */
174 typedef struct case_node case_node;
175 typedef struct case_node *case_node_ptr;
177 /* These are used by estimate_case_costs and balance_case_nodes. */
179 /* This must be a signed type, and non-ANSI compilers lack signed char. */
180 static short *cost_table;
181 static int use_cost_table;
183 /* Stack of control and binding constructs we are currently inside.
185 These constructs begin when you call `expand_start_WHATEVER'
186 and end when you call `expand_end_WHATEVER'. This stack records
187 info about how the construct began that tells the end-function
188 what to do. It also may provide information about the construct
189 to alter the behavior of other constructs within the body.
190 For example, they may affect the behavior of C `break' and `continue'.
192 Each construct gets one `struct nesting' object.
193 All of these objects are chained through the `all' field.
194 `nesting_stack' points to the first object (innermost construct).
195 The position of an entry on `nesting_stack' is in its `depth' field.
197 Each type of construct has its own individual stack.
198 For example, loops have `loop_stack'. Each object points to the
199 next object of the same type through the `next' field.
201 Some constructs are visible to `break' exit-statements and others
202 are not. Which constructs are visible depends on the language.
203 Therefore, the data structure allows each construct to be visible
204 or not, according to the args given when the construct is started.
205 The construct is visible if the `exit_label' field is non-null.
206 In that case, the value should be a CODE_LABEL rtx. */
211 struct nesting *next;
216 /* For conds (if-then and if-then-else statements). */
219 /* Label for the end of the if construct.
220 There is none if EXITFLAG was not set
221 and no `else' has been seen yet. */
223 /* Label for the end of this alternative.
224 This may be the end of the if or the next else/elseif. */
230 /* Label at the top of the loop; place to loop back to. */
232 /* Label at the end of the whole construct. */
234 /* Label before a jump that branches to the end of the whole
235 construct. This is where destructors go if any. */
237 /* Label for `continue' statement to jump to;
238 this is in front of the stepper of the loop. */
241 /* For variable binding contours. */
244 /* Sequence number of this binding contour within the function,
245 in order of entry. */
246 int block_start_count;
247 /* Nonzero => value to restore stack to on exit. Complemented by
248 bc_stack_level (see below) when generating bytecodes. */
250 /* The NOTE that starts this contour.
251 Used by expand_goto to check whether the destination
252 is within each contour or not. */
254 /* Innermost containing binding contour that has a stack level. */
255 struct nesting *innermost_stack_block;
256 /* List of cleanups to be run on exit from this contour.
257 This is a list of expressions to be evaluated.
258 The TREE_PURPOSE of each link is the ..._DECL node
259 which the cleanup pertains to. */
261 /* List of cleanup-lists of blocks containing this block,
262 as they were at the locus where this block appears.
263 There is an element for each containing block,
264 ordered innermost containing block first.
265 The tail of this list can be 0 (was empty_cleanup_list),
266 if all remaining elements would be empty lists.
267 The element's TREE_VALUE is the cleanup-list of that block,
268 which may be null. */
270 /* Chain of labels defined inside this binding contour.
271 For contours that have stack levels or cleanups. */
272 struct label_chain *label_chain;
273 /* Number of function calls seen, as of start of this block. */
274 int function_call_count;
275 /* Bytecode specific: stack level to restore stack to on exit. */
278 /* For switch (C) or case (Pascal) statements,
279 and also for dummies (see `expand_start_case_dummy'). */
282 /* The insn after which the case dispatch should finally
283 be emitted. Zero for a dummy. */
285 /* For bytecodes, the case table is in-lined right in the code.
286 A label is needed for skipping over this block. It is only
287 used when generating bytecodes. */
289 /* A list of case labels; it is first built as an AVL tree.
290 During expand_end_case, this is converted to a list, and may be
291 rearranged into a nearly balanced binary tree. */
292 struct case_node *case_list;
293 /* Label to jump to if no case matches. */
295 /* The expression to be dispatched on. */
297 /* Type that INDEX_EXPR should be converted to. */
299 /* Number of range exprs in case statement. */
301 /* Name of this kind of statement, for warnings. */
303 /* Nonzero if a case label has been seen in this case stmt. */
309 /* Chain of all pending binding contours. */
310 struct nesting *block_stack;
312 /* If any new stacks are added here, add them to POPSTACKS too. */
314 /* Chain of all pending binding contours that restore stack levels
316 struct nesting *stack_block_stack;
318 /* Chain of all pending conditional statements. */
319 struct nesting *cond_stack;
321 /* Chain of all pending loops. */
322 struct nesting *loop_stack;
324 /* Chain of all pending case or switch statements. */
325 struct nesting *case_stack;
327 /* Separate chain including all of the above,
328 chained through the `all' field. */
329 struct nesting *nesting_stack;
331 /* Number of entries on nesting_stack now. */
334 /* Allocate and return a new `struct nesting'. */
336 #define ALLOC_NESTING() \
337 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
339 /* Pop the nesting stack element by element until we pop off
340 the element which is at the top of STACK.
341 Update all the other stacks, popping off elements from them
342 as we pop them from nesting_stack. */
344 #define POPSTACK(STACK) \
345 do { struct nesting *target = STACK; \
346 struct nesting *this; \
347 do { this = nesting_stack; \
348 if (loop_stack == this) \
349 loop_stack = loop_stack->next; \
350 if (cond_stack == this) \
351 cond_stack = cond_stack->next; \
352 if (block_stack == this) \
353 block_stack = block_stack->next; \
354 if (stack_block_stack == this) \
355 stack_block_stack = stack_block_stack->next; \
356 if (case_stack == this) \
357 case_stack = case_stack->next; \
358 nesting_depth = nesting_stack->depth - 1; \
359 nesting_stack = this->all; \
360 obstack_free (&stmt_obstack, this); } \
361 while (this != target); } while (0)
363 /* In some cases it is impossible to generate code for a forward goto
364 until the label definition is seen. This happens when it may be necessary
365 for the goto to reset the stack pointer: we don't yet know how to do that.
366 So expand_goto puts an entry on this fixup list.
367 Each time a binding contour that resets the stack is exited,
369 If the target label has now been defined, we can insert the proper code. */
373 /* Points to following fixup. */
374 struct goto_fixup *next;
375 /* Points to the insn before the jump insn.
376 If more code must be inserted, it goes after this insn. */
378 /* The LABEL_DECL that this jump is jumping to, or 0
379 for break, continue or return. */
381 /* The BLOCK for the place where this goto was found. */
383 /* The CODE_LABEL rtx that this is jumping to. */
385 /* Number of binding contours started in current function
386 before the label reference. */
387 int block_start_count;
388 /* The outermost stack level that should be restored for this jump.
389 Each time a binding contour that resets the stack is exited,
390 if the target label is *not* yet defined, this slot is updated. */
392 /* List of lists of cleanup expressions to be run by this goto.
393 There is one element for each block that this goto is within.
394 The tail of this list can be 0 (was empty_cleanup_list),
395 if all remaining elements would be empty.
396 The TREE_VALUE contains the cleanup list of that block as of the
397 time this goto was seen.
398 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
399 tree cleanup_list_list;
401 /* Bytecode specific members follow */
403 /* The label that this jump is jumping to, or 0 for break, continue
405 struct bc_label *bc_target;
407 /* The label we use for the fixup patch */
408 struct bc_label *label;
410 /* True (non-0) if fixup has been handled */
413 /* Like stack_level above, except refers to the interpreter stack */
417 static struct goto_fixup *goto_fixup_chain;
419 /* Within any binding contour that must restore a stack level,
420 all labels are recorded with a chain of these structures. */
424 /* Points to following fixup. */
425 struct label_chain *next;
428 static void expand_goto_internal PROTO((tree, rtx, rtx));
429 static void bc_expand_goto_internal PROTO((enum bytecode_opcode,
430 struct bc_label *, tree));
431 static int expand_fixup PROTO((tree, rtx, rtx));
432 static void bc_expand_fixup PROTO((enum bytecode_opcode,
433 struct bc_label *, int));
434 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
436 static void bc_fixup_gotos PROTO((struct nesting *, int, tree,
438 static void bc_expand_start_cond PROTO((tree, int));
439 static void bc_expand_end_cond PROTO((void));
440 static void bc_expand_start_else PROTO((void));
441 static void bc_expand_end_loop PROTO((void));
442 static void bc_expand_end_bindings PROTO((tree, int, int));
443 static void bc_expand_decl PROTO((tree, tree));
444 static void bc_expand_variable_local_init PROTO((tree));
445 static void bc_expand_decl_init PROTO((tree));
446 static void expand_null_return_1 PROTO((rtx, int));
447 static void expand_value_return PROTO((rtx));
448 static int tail_recursion_args PROTO((tree, tree));
449 static void expand_cleanups PROTO((tree, tree, int, int));
450 static void bc_expand_start_case PROTO((struct nesting *, tree,
452 static int bc_pushcase PROTO((tree, tree));
453 static void bc_check_for_full_enumeration_handling PROTO((tree));
454 static void bc_expand_end_case PROTO((tree));
455 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
456 static int estimate_case_costs PROTO((case_node_ptr));
457 static void group_case_nodes PROTO((case_node_ptr));
458 static void balance_case_nodes PROTO((case_node_ptr *,
460 static int node_has_low_bound PROTO((case_node_ptr, tree));
461 static int node_has_high_bound PROTO((case_node_ptr, tree));
462 static int node_is_bounded PROTO((case_node_ptr, tree));
463 static void emit_jump_if_reachable PROTO((rtx));
464 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
465 static int add_case_node PROTO((tree, tree, tree, tree *));
466 static struct case_node *case_tree2list PROTO((case_node *, case_node *));
468 extern rtx bc_allocate_local ();
469 extern rtx bc_allocate_variable_array ();
474 gcc_obstack_init (&stmt_obstack);
476 empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE);
481 init_stmt_for_function ()
483 /* We are not currently within any block, conditional, loop or case. */
485 stack_block_stack = 0;
492 block_start_count = 0;
494 /* No gotos have been expanded yet. */
495 goto_fixup_chain = 0;
497 /* We are not processing a ({...}) grouping. */
498 expr_stmts_for_value = 0;
506 p->block_stack = block_stack;
507 p->stack_block_stack = stack_block_stack;
508 p->cond_stack = cond_stack;
509 p->loop_stack = loop_stack;
510 p->case_stack = case_stack;
511 p->nesting_stack = nesting_stack;
512 p->nesting_depth = nesting_depth;
513 p->block_start_count = block_start_count;
514 p->last_expr_type = last_expr_type;
515 p->last_expr_value = last_expr_value;
516 p->expr_stmts_for_value = expr_stmts_for_value;
517 p->emit_filename = emit_filename;
518 p->emit_lineno = emit_lineno;
519 p->goto_fixup_chain = goto_fixup_chain;
523 restore_stmt_status (p)
526 block_stack = p->block_stack;
527 stack_block_stack = p->stack_block_stack;
528 cond_stack = p->cond_stack;
529 loop_stack = p->loop_stack;
530 case_stack = p->case_stack;
531 nesting_stack = p->nesting_stack;
532 nesting_depth = p->nesting_depth;
533 block_start_count = p->block_start_count;
534 last_expr_type = p->last_expr_type;
535 last_expr_value = p->last_expr_value;
536 expr_stmts_for_value = p->expr_stmts_for_value;
537 emit_filename = p->emit_filename;
538 emit_lineno = p->emit_lineno;
539 goto_fixup_chain = p->goto_fixup_chain;
542 /* Emit a no-op instruction. */
549 if (!output_bytecode)
551 last_insn = get_last_insn ();
553 && (GET_CODE (last_insn) == CODE_LABEL
554 || (GET_CODE (last_insn) == NOTE
555 && prev_real_insn (last_insn) == 0)))
556 emit_insn (gen_nop ());
560 /* Return the rtx-label that corresponds to a LABEL_DECL,
561 creating it if necessary. */
567 if (TREE_CODE (label) != LABEL_DECL)
570 if (DECL_RTL (label))
571 return DECL_RTL (label);
573 return DECL_RTL (label) = gen_label_rtx ();
576 /* Add an unconditional jump to LABEL as the next sequential instruction. */
582 do_pending_stack_adjust ();
583 emit_jump_insn (gen_jump (label));
587 /* Emit code to jump to the address
588 specified by the pointer expression EXP. */
591 expand_computed_goto (exp)
596 bc_expand_expr (exp);
597 bc_emit_instruction (jumpP);
601 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
603 #ifdef POINTERS_EXTEND_UNSIGNED
604 x = convert_memory_address (Pmode, x);
608 do_pending_stack_adjust ();
609 emit_indirect_jump (x);
613 /* Handle goto statements and the labels that they can go to. */
615 /* Specify the location in the RTL code of a label LABEL,
616 which is a LABEL_DECL tree node.
618 This is used for the kind of label that the user can jump to with a
619 goto statement, and for alternatives of a switch or case statement.
620 RTL labels generated for loops and conditionals don't go through here;
621 they are generated directly at the RTL level, by other functions below.
623 Note that this has nothing to do with defining label *names*.
624 Languages vary in how they do that and what that even means. */
630 struct label_chain *p;
634 if (! DECL_RTL (label))
635 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
636 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
637 error ("multiply defined label");
641 do_pending_stack_adjust ();
642 emit_label (label_rtx (label));
643 if (DECL_NAME (label))
644 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
646 if (stack_block_stack != 0)
648 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
649 p->next = stack_block_stack->data.block.label_chain;
650 stack_block_stack->data.block.label_chain = p;
655 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
656 from nested functions. */
659 declare_nonlocal_label (label)
662 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
663 LABEL_PRESERVE_P (label_rtx (label)) = 1;
664 if (nonlocal_goto_handler_slot == 0)
666 nonlocal_goto_handler_slot
667 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
668 emit_stack_save (SAVE_NONLOCAL,
669 &nonlocal_goto_stack_level,
670 PREV_INSN (tail_recursion_reentry));
674 /* Generate RTL code for a `goto' statement with target label LABEL.
675 LABEL should be a LABEL_DECL tree node that was or will later be
676 defined with `expand_label'. */
686 expand_goto_internal (label, label_rtx (label), NULL_RTX);
690 /* Check for a nonlocal goto to a containing function. */
691 context = decl_function_context (label);
692 if (context != 0 && context != current_function_decl)
694 struct function *p = find_function_data (context);
695 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
698 p->has_nonlocal_label = 1;
699 current_function_has_nonlocal_goto = 1;
700 LABEL_REF_NONLOCAL_P (label_ref) = 1;
702 /* Copy the rtl for the slots so that they won't be shared in
703 case the virtual stack vars register gets instantiated differently
704 in the parent than in the child. */
706 #if HAVE_nonlocal_goto
707 if (HAVE_nonlocal_goto)
708 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
709 copy_rtx (p->nonlocal_goto_handler_slot),
710 copy_rtx (p->nonlocal_goto_stack_level),
717 /* Restore frame pointer for containing function.
718 This sets the actual hard register used for the frame pointer
719 to the location of the function's incoming static chain info.
720 The non-local goto handler will then adjust it to contain the
721 proper value and reload the argument pointer, if needed. */
722 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
724 /* We have now loaded the frame pointer hardware register with
725 the address of that corresponds to the start of the virtual
726 stack vars. So replace virtual_stack_vars_rtx in all
727 addresses we use with stack_pointer_rtx. */
729 /* Get addr of containing function's current nonlocal goto handler,
730 which will do any cleanups and then jump to the label. */
731 addr = copy_rtx (p->nonlocal_goto_handler_slot);
732 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
733 hard_frame_pointer_rtx));
735 /* Restore the stack pointer. Note this uses fp just restored. */
736 addr = p->nonlocal_goto_stack_level;
738 addr = replace_rtx (copy_rtx (addr),
739 virtual_stack_vars_rtx,
740 hard_frame_pointer_rtx);
742 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
744 /* Put in the static chain register the nonlocal label address. */
745 emit_move_insn (static_chain_rtx, label_ref);
746 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
748 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
749 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
750 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
751 emit_indirect_jump (temp);
755 expand_goto_internal (label, label_rtx (label), NULL_RTX);
758 /* Generate RTL code for a `goto' statement with target label BODY.
759 LABEL should be a LABEL_REF.
760 LAST_INSN, if non-0, is the rtx we should consider as the last
761 insn emitted (for the purposes of cleaning up a return). */
764 expand_goto_internal (body, label, last_insn)
769 struct nesting *block;
772 /* NOTICE! If a bytecode instruction other than `jump' is needed,
773 then the caller has to call bc_expand_goto_internal()
774 directly. This is rather an exceptional case, and there aren't
775 that many places where this is necessary. */
778 expand_goto_internal (body, label, last_insn);
782 if (GET_CODE (label) != CODE_LABEL)
785 /* If label has already been defined, we can tell now
786 whether and how we must alter the stack level. */
788 if (PREV_INSN (label) != 0)
790 /* Find the innermost pending block that contains the label.
791 (Check containment by comparing insn-uids.)
792 Then restore the outermost stack level within that block,
793 and do cleanups of all blocks contained in it. */
794 for (block = block_stack; block; block = block->next)
796 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
798 if (block->data.block.stack_level != 0)
799 stack_level = block->data.block.stack_level;
800 /* Execute the cleanups for blocks we are exiting. */
801 if (block->data.block.cleanups != 0)
803 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
804 do_pending_stack_adjust ();
810 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
811 the stack pointer. This one should be deleted as dead by flow. */
812 clear_pending_stack_adjust ();
813 do_pending_stack_adjust ();
814 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
817 if (body != 0 && DECL_TOO_LATE (body))
818 error ("jump to `%s' invalidly jumps into binding contour",
819 IDENTIFIER_POINTER (DECL_NAME (body)));
821 /* Label not yet defined: may need to put this goto
822 on the fixup list. */
823 else if (! expand_fixup (body, label, last_insn))
825 /* No fixup needed. Record that the label is the target
826 of at least one goto that has no fixup. */
828 TREE_ADDRESSABLE (body) = 1;
834 /* Generate a jump with OPCODE to the given bytecode LABEL which is
835 found within BODY. */
838 bc_expand_goto_internal (opcode, label, body)
839 enum bytecode_opcode opcode;
840 struct bc_label *label;
843 struct nesting *block;
844 int stack_level = -1;
846 /* If the label is defined, adjust the stack as necessary.
847 If it's not defined, we have to push the reference on the
853 /* Find the innermost pending block that contains the label.
854 (Check containment by comparing bytecode uids.) Then restore the
855 outermost stack level within that block. */
857 for (block = block_stack; block; block = block->next)
859 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
861 if (block->data.block.bc_stack_level)
862 stack_level = block->data.block.bc_stack_level;
864 /* Execute the cleanups for blocks we are exiting. */
865 if (block->data.block.cleanups != 0)
867 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
868 do_pending_stack_adjust ();
872 /* Restore the stack level. If we need to adjust the stack, we
873 must do so after the jump, since the jump may depend on
874 what's on the stack. Thus, any stack-modifying conditional
875 jumps (these are the only ones that rely on what's on the
876 stack) go into the fixup list. */
879 && stack_depth != stack_level
882 bc_expand_fixup (opcode, label, stack_level);
885 if (stack_level >= 0)
886 bc_adjust_stack (stack_depth - stack_level);
888 if (body && DECL_BIT_FIELD (body))
889 error ("jump to `%s' invalidly jumps into binding contour",
890 IDENTIFIER_POINTER (DECL_NAME (body)));
892 /* Emit immediate jump */
893 bc_emit_bytecode (opcode);
894 bc_emit_bytecode_labelref (label);
896 #ifdef DEBUG_PRINT_CODE
897 fputc ('\n', stderr);
902 /* Put goto in the fixup list */
903 bc_expand_fixup (opcode, label, stack_level);
906 /* Generate if necessary a fixup for a goto
907 whose target label in tree structure (if any) is TREE_LABEL
908 and whose target in rtl is RTL_LABEL.
910 If LAST_INSN is nonzero, we pretend that the jump appears
911 after insn LAST_INSN instead of at the current point in the insn stream.
913 The fixup will be used later to insert insns just before the goto.
914 Those insns will restore the stack level as appropriate for the
915 target label, and will (in the case of C++) also invoke any object
916 destructors which have to be invoked when we exit the scopes which
917 are exited by the goto.
919 Value is nonzero if a fixup is made. */
922 expand_fixup (tree_label, rtl_label, last_insn)
927 struct nesting *block, *end_block;
929 /* See if we can recognize which block the label will be output in.
930 This is possible in some very common cases.
931 If we succeed, set END_BLOCK to that block.
932 Otherwise, set it to 0. */
935 && (rtl_label == cond_stack->data.cond.endif_label
936 || rtl_label == cond_stack->data.cond.next_label))
937 end_block = cond_stack;
938 /* If we are in a loop, recognize certain labels which
939 are likely targets. This reduces the number of fixups
940 we need to create. */
942 && (rtl_label == loop_stack->data.loop.start_label
943 || rtl_label == loop_stack->data.loop.end_label
944 || rtl_label == loop_stack->data.loop.continue_label))
945 end_block = loop_stack;
949 /* Now set END_BLOCK to the binding level to which we will return. */
953 struct nesting *next_block = end_block->all;
956 /* First see if the END_BLOCK is inside the innermost binding level.
957 If so, then no cleanups or stack levels are relevant. */
958 while (next_block && next_block != block)
959 next_block = next_block->all;
964 /* Otherwise, set END_BLOCK to the innermost binding level
965 which is outside the relevant control-structure nesting. */
966 next_block = block_stack->next;
967 for (block = block_stack; block != end_block; block = block->all)
968 if (block == next_block)
969 next_block = next_block->next;
970 end_block = next_block;
973 /* Does any containing block have a stack level or cleanups?
974 If not, no fixup is needed, and that is the normal case
975 (the only case, for standard C). */
976 for (block = block_stack; block != end_block; block = block->next)
977 if (block->data.block.stack_level != 0
978 || block->data.block.cleanups != 0)
981 if (block != end_block)
983 /* Ok, a fixup is needed. Add a fixup to the list of such. */
984 struct goto_fixup *fixup
985 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
986 /* In case an old stack level is restored, make sure that comes
987 after any pending stack adjust. */
988 /* ?? If the fixup isn't to come at the present position,
989 doing the stack adjust here isn't useful. Doing it with our
990 settings at that location isn't useful either. Let's hope
993 do_pending_stack_adjust ();
994 fixup->target = tree_label;
995 fixup->target_rtl = rtl_label;
997 /* Create a BLOCK node and a corresponding matched set of
998 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
999 this point. The notes will encapsulate any and all fixup
1000 code which we might later insert at this point in the insn
1001 stream. Also, the BLOCK node will be the parent (i.e. the
1002 `SUPERBLOCK') of any other BLOCK nodes which we might create
1003 later on when we are expanding the fixup code. */
1006 register rtx original_before_jump
1007 = last_insn ? last_insn : get_last_insn ();
1011 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1012 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1013 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1015 emit_insns_after (fixup->before_jump, original_before_jump);
1018 fixup->block_start_count = block_start_count;
1019 fixup->stack_level = 0;
1020 fixup->cleanup_list_list
1021 = (((block->data.block.outer_cleanups
1023 && block->data.block.outer_cleanups != empty_cleanup_list
1026 || block->data.block.cleanups)
1027 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1028 block->data.block.outer_cleanups)
1030 fixup->next = goto_fixup_chain;
1031 goto_fixup_chain = fixup;
1038 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1039 Make the fixup restore the stack level to STACK_LEVEL. */
1042 bc_expand_fixup (opcode, label, stack_level)
1043 enum bytecode_opcode opcode;
1044 struct bc_label *label;
1047 struct goto_fixup *fixup
1048 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1050 fixup->label = bc_get_bytecode_label ();
1051 fixup->bc_target = label;
1052 fixup->bc_stack_level = stack_level;
1053 fixup->bc_handled = FALSE;
1055 fixup->next = goto_fixup_chain;
1056 goto_fixup_chain = fixup;
1058 /* Insert a jump to the fixup code */
1059 bc_emit_bytecode (opcode);
1060 bc_emit_bytecode_labelref (fixup->label);
1062 #ifdef DEBUG_PRINT_CODE
1063 fputc ('\n', stderr);
1067 /* Expand any needed fixups in the outputmost binding level of the
1068 function. FIRST_INSN is the first insn in the function. */
1071 expand_fixups (first_insn)
1074 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1077 /* When exiting a binding contour, process all pending gotos requiring fixups.
1078 THISBLOCK is the structure that describes the block being exited.
1079 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1080 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1081 FIRST_INSN is the insn that began this contour.
1083 Gotos that jump out of this contour must restore the
1084 stack level and do the cleanups before actually jumping.
1086 DONT_JUMP_IN nonzero means report error there is a jump into this
1087 contour from before the beginning of the contour.
1088 This is also done if STACK_LEVEL is nonzero. */
1091 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1092 struct nesting *thisblock;
1098 register struct goto_fixup *f, *prev;
1100 if (output_bytecode)
1102 /* ??? The second arg is the bc stack level, which is not the same
1103 as STACK_LEVEL. I have no idea what should go here, so I'll
1105 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1109 /* F is the fixup we are considering; PREV is the previous one. */
1110 /* We run this loop in two passes so that cleanups of exited blocks
1111 are run first, and blocks that are exited are marked so
1114 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1116 /* Test for a fixup that is inactive because it is already handled. */
1117 if (f->before_jump == 0)
1119 /* Delete inactive fixup from the chain, if that is easy to do. */
1121 prev->next = f->next;
1123 /* Has this fixup's target label been defined?
1124 If so, we can finalize it. */
1125 else if (PREV_INSN (f->target_rtl) != 0)
1127 register rtx cleanup_insns;
1129 /* Get the first non-label after the label
1130 this goto jumps to. If that's before this scope begins,
1131 we don't have a jump into the scope. */
1132 rtx after_label = f->target_rtl;
1133 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1134 after_label = NEXT_INSN (after_label);
1136 /* If this fixup jumped into this contour from before the beginning
1137 of this contour, report an error. */
1138 /* ??? Bug: this does not detect jumping in through intermediate
1139 blocks that have stack levels or cleanups.
1140 It detects only a problem with the innermost block
1141 around the label. */
1143 && (dont_jump_in || stack_level || cleanup_list)
1144 /* If AFTER_LABEL is 0, it means the jump goes to the end
1145 of the rtl, which means it jumps into this scope. */
1146 && (after_label == 0
1147 || INSN_UID (first_insn) < INSN_UID (after_label))
1148 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1149 && ! DECL_ERROR_ISSUED (f->target))
1151 error_with_decl (f->target,
1152 "label `%s' used before containing binding contour");
1153 /* Prevent multiple errors for one label. */
1154 DECL_ERROR_ISSUED (f->target) = 1;
1157 /* We will expand the cleanups into a sequence of their own and
1158 then later on we will attach this new sequence to the insn
1159 stream just ahead of the actual jump insn. */
1163 /* Temporarily restore the lexical context where we will
1164 logically be inserting the fixup code. We do this for the
1165 sake of getting the debugging information right. */
1168 set_block (f->context);
1170 /* Expand the cleanups for blocks this jump exits. */
1171 if (f->cleanup_list_list)
1174 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1175 /* Marked elements correspond to blocks that have been closed.
1176 Do their cleanups. */
1177 if (TREE_ADDRESSABLE (lists)
1178 && TREE_VALUE (lists) != 0)
1180 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1181 /* Pop any pushes done in the cleanups,
1182 in case function is about to return. */
1183 do_pending_stack_adjust ();
1187 /* Restore stack level for the biggest contour that this
1188 jump jumps out of. */
1190 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1192 /* Finish up the sequence containing the insns which implement the
1193 necessary cleanups, and then attach that whole sequence to the
1194 insn stream just ahead of the actual jump insn. Attaching it
1195 at that point insures that any cleanups which are in fact
1196 implicit C++ object destructions (which must be executed upon
1197 leaving the block) appear (to the debugger) to be taking place
1198 in an area of the generated code where the object(s) being
1199 destructed are still "in scope". */
1201 cleanup_insns = get_insns ();
1205 emit_insns_after (cleanup_insns, f->before_jump);
1212 /* For any still-undefined labels, do the cleanups for this block now.
1213 We must do this now since items in the cleanup list may go out
1214 of scope when the block ends. */
1215 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1216 if (f->before_jump != 0
1217 && PREV_INSN (f->target_rtl) == 0
1218 /* Label has still not appeared. If we are exiting a block with
1219 a stack level to restore, that started before the fixup,
1220 mark this stack level as needing restoration
1221 when the fixup is later finalized. */
1223 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1224 means the label is undefined. That's erroneous, but possible. */
1225 && (thisblock->data.block.block_start_count
1226 <= f->block_start_count))
1228 tree lists = f->cleanup_list_list;
1231 for (; lists; lists = TREE_CHAIN (lists))
1232 /* If the following elt. corresponds to our containing block
1233 then the elt. must be for this block. */
1234 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1238 set_block (f->context);
1239 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1240 do_pending_stack_adjust ();
1241 cleanup_insns = get_insns ();
1245 = emit_insns_after (cleanup_insns, f->before_jump);
1247 f->cleanup_list_list = TREE_CHAIN (lists);
1251 f->stack_level = stack_level;
1256 /* When exiting a binding contour, process all pending gotos requiring fixups.
1257 Note: STACK_DEPTH is not altered.
1259 The arguments are currently not used in the bytecode compiler, but we may
1260 need them one day for languages other than C.
1262 THISBLOCK is the structure that describes the block being exited.
1263 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1264 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1265 FIRST_INSN is the insn that began this contour.
1267 Gotos that jump out of this contour must restore the
1268 stack level and do the cleanups before actually jumping.
1270 DONT_JUMP_IN nonzero means report error there is a jump into this
1271 contour from before the beginning of the contour.
1272 This is also done if STACK_LEVEL is nonzero. */
1275 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1276 struct nesting *thisblock;
1282 register struct goto_fixup *f, *prev;
1283 int saved_stack_depth;
1285 /* F is the fixup we are considering; PREV is the previous one. */
1287 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1289 /* Test for a fixup that is inactive because it is already handled. */
1290 if (f->before_jump == 0)
1292 /* Delete inactive fixup from the chain, if that is easy to do. */
1294 prev->next = f->next;
1297 /* Emit code to restore the stack and continue */
1298 bc_emit_bytecode_labeldef (f->label);
1300 /* Save stack_depth across call, since bc_adjust_stack () will alter
1301 the perceived stack depth via the instructions generated. */
1303 if (f->bc_stack_level >= 0)
1305 saved_stack_depth = stack_depth;
1306 bc_adjust_stack (stack_depth - f->bc_stack_level);
1307 stack_depth = saved_stack_depth;
1310 bc_emit_bytecode (jump);
1311 bc_emit_bytecode_labelref (f->bc_target);
1313 #ifdef DEBUG_PRINT_CODE
1314 fputc ('\n', stderr);
1318 goto_fixup_chain = NULL;
1321 /* Generate RTL for an asm statement (explicit assembler code).
1322 BODY is a STRING_CST node containing the assembler code text,
1323 or an ADDR_EXPR containing a STRING_CST. */
1329 if (output_bytecode)
1331 error ("`asm' is invalid when generating bytecode");
1335 if (TREE_CODE (body) == ADDR_EXPR)
1336 body = TREE_OPERAND (body, 0);
1338 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1339 TREE_STRING_POINTER (body)));
1343 /* Generate RTL for an asm statement with arguments.
1344 STRING is the instruction template.
1345 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1346 Each output or input has an expression in the TREE_VALUE and
1347 a constraint-string in the TREE_PURPOSE.
1348 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1349 that is clobbered by this insn.
1351 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1352 Some elements of OUTPUTS may be replaced with trees representing temporary
1353 values. The caller should copy those temporary values to the originally
1356 VOL nonzero means the insn is volatile; don't optimize it. */
1359 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1360 tree string, outputs, inputs, clobbers;
1365 rtvec argvec, constraints;
1367 int ninputs = list_length (inputs);
1368 int noutputs = list_length (outputs);
1372 /* Vector of RTX's of evaluated output operands. */
1373 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1374 /* The insn we have emitted. */
1377 if (output_bytecode)
1379 error ("`asm' is invalid when generating bytecode");
1383 /* Count the number of meaningful clobbered registers, ignoring what
1384 we would ignore later. */
1386 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1388 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1389 i = decode_reg_name (regname);
1390 if (i >= 0 || i == -4)
1393 error ("unknown register name `%s' in `asm'", regname);
1398 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1400 tree val = TREE_VALUE (tail);
1401 tree type = TREE_TYPE (val);
1404 int found_equal = 0;
1407 /* If there's an erroneous arg, emit no insn. */
1408 if (TREE_TYPE (val) == error_mark_node)
1411 /* Make sure constraint has `=' and does not have `+'. Also, see
1412 if it allows any register. Be liberal on the latter test, since
1413 the worst that happens if we get it wrong is we issue an error
1416 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1417 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1420 error ("output operand constraint contains `+'");
1427 case '?': case '!': case '*': case '%': case '&':
1428 case 'V': case 'm': case 'o': case '<': case '>':
1429 case 'E': case 'F': case 'G': case 'H': case 'X':
1430 case 's': case 'i': case 'n':
1431 case 'I': case 'J': case 'K': case 'L': case 'M':
1432 case 'N': case 'O': case 'P': case ',':
1433 #ifdef EXTRA_CONSTRAINT
1434 case 'Q': case 'R': case 'S': case 'T': case 'U':
1438 case 'p': case 'g': case 'r':
1439 /* Whether or not a numeric constraint allows a register is
1440 decided by the matching constraint, and so there is no need
1441 to do anything special with them. We must handle them in
1442 the default case, so that we don't unnecessarily force
1443 operands to memory. */
1444 case '0': case '1': case '2': case '3': case '4':
1452 error ("output operand constraint lacks `='");
1456 /* If an output operand is not a decl or indirect ref and our constraint
1457 allows a register, make a temporary to act as an intermediate.
1458 Make the asm insn write into that, then our caller will copy it to
1459 the real output operand. Likewise for promoted variables. */
1461 if (TREE_CODE (val) == INDIRECT_REF
1462 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1463 && ! (GET_CODE (DECL_RTL (val)) == REG
1464 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1468 mark_addressable (TREE_VALUE (tail));
1471 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1473 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1474 error ("output number %d not directly addressable", i);
1478 output_rtx[i] = assign_temp (type, 0, 0, 0);
1479 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1483 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1485 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1489 /* Make vectors for the expression-rtx and constraint strings. */
1491 argvec = rtvec_alloc (ninputs);
1492 constraints = rtvec_alloc (ninputs);
1494 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1495 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1497 MEM_VOLATILE_P (body) = vol;
1499 /* Eval the inputs and put them into ARGVEC.
1500 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1503 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1508 /* If there's an erroneous arg, emit no insn,
1509 because the ASM_INPUT would get VOIDmode
1510 and that could cause a crash in reload. */
1511 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1513 if (TREE_PURPOSE (tail) == NULL_TREE)
1515 error ("hard register `%s' listed as input operand to `asm'",
1516 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1520 /* Make sure constraint has neither `=' nor `+'. */
1522 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1523 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1526 error ("input operand constraint contains `%c'",
1527 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1530 case '?': case '!': case '*': case '%': case '&':
1531 case 'V': case 'm': case 'o': case '<': case '>':
1532 case 'E': case 'F': case 'G': case 'H': case 'X':
1533 case 's': case 'i': case 'n':
1534 case 'I': case 'J': case 'K': case 'L': case 'M':
1535 case 'N': case 'O': case 'P': case ',':
1536 #ifdef EXTRA_CONSTRAINT
1537 case 'Q': case 'R': case 'S': case 'T': case 'U':
1541 case 'p': case 'g': case 'r':
1542 /* Whether or not a numeric constraint allows a register is
1543 decided by the matching constraint, and so there is no need
1544 to do anything special with them. We must handle them in
1545 the default case, so that we don't unnecessarily force
1546 operands to memory. */
1547 case '0': case '1': case '2': case '3': case '4':
1554 mark_addressable (TREE_VALUE (tail));
1556 XVECEXP (body, 3, i) /* argvec */
1557 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1558 if (CONSTANT_P (XVECEXP (body, 3, i))
1559 && ! general_operand (XVECEXP (body, 3, i),
1560 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1563 XVECEXP (body, 3, i)
1564 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1565 XVECEXP (body, 3, i));
1567 XVECEXP (body, 3, i)
1568 = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1569 XVECEXP (body, 3, i));
1573 && (GET_CODE (XVECEXP (body, 3, i)) == REG
1574 || GET_CODE (XVECEXP (body, 3, i)) == SUBREG
1575 || GET_CODE (XVECEXP (body, 3, i)) == CONCAT))
1577 tree type = TREE_TYPE (TREE_VALUE (tail));
1578 rtx memloc = assign_temp (type, 1, 1, 1);
1580 emit_move_insn (memloc, XVECEXP (body, 3, i));
1581 XVECEXP (body, 3, i) = memloc;
1584 XVECEXP (body, 4, i) /* constraints */
1585 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1586 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1590 /* Protect all the operands from the queue,
1591 now that they have all been evaluated. */
1593 for (i = 0; i < ninputs; i++)
1594 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1596 for (i = 0; i < noutputs; i++)
1597 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1599 /* Now, for each output, construct an rtx
1600 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1601 ARGVEC CONSTRAINTS))
1602 If there is more than one, put them inside a PARALLEL. */
1604 if (noutputs == 1 && nclobbers == 0)
1606 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1607 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1609 else if (noutputs == 0 && nclobbers == 0)
1611 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1612 insn = emit_insn (body);
1618 if (num == 0) num = 1;
1619 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1621 /* For each output operand, store a SET. */
1623 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1625 XVECEXP (body, 0, i)
1626 = gen_rtx (SET, VOIDmode,
1628 gen_rtx (ASM_OPERANDS, VOIDmode,
1629 TREE_STRING_POINTER (string),
1630 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1631 i, argvec, constraints,
1633 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1636 /* If there are no outputs (but there are some clobbers)
1637 store the bare ASM_OPERANDS into the PARALLEL. */
1640 XVECEXP (body, 0, i++) = obody;
1642 /* Store (clobber REG) for each clobbered register specified. */
1644 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1646 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1647 int j = decode_reg_name (regname);
1651 if (j == -3) /* `cc', which is not a register */
1654 if (j == -4) /* `memory', don't cache memory across asm */
1656 XVECEXP (body, 0, i++)
1657 = gen_rtx (CLOBBER, VOIDmode,
1658 gen_rtx (MEM, BLKmode,
1659 gen_rtx (SCRATCH, VOIDmode, 0)));
1663 /* Ignore unknown register, error already signalled. */
1667 /* Use QImode since that's guaranteed to clobber just one reg. */
1668 XVECEXP (body, 0, i++)
1669 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1672 insn = emit_insn (body);
1678 /* Generate RTL to evaluate the expression EXP
1679 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1682 expand_expr_stmt (exp)
1685 if (output_bytecode)
1687 int org_stack_depth = stack_depth;
1689 bc_expand_expr (exp);
1691 /* Restore stack depth */
1692 if (stack_depth < org_stack_depth)
1695 bc_emit_instruction (drop);
1697 last_expr_type = TREE_TYPE (exp);
1701 /* If -W, warn about statements with no side effects,
1702 except for an explicit cast to void (e.g. for assert()), and
1703 except inside a ({...}) where they may be useful. */
1704 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1706 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1707 && !(TREE_CODE (exp) == CONVERT_EXPR
1708 && TREE_TYPE (exp) == void_type_node))
1709 warning_with_file_and_line (emit_filename, emit_lineno,
1710 "statement with no effect");
1711 else if (warn_unused)
1712 warn_if_unused_value (exp);
1715 /* If EXP is of function type and we are expanding statements for
1716 value, convert it to pointer-to-function. */
1717 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1718 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1720 last_expr_type = TREE_TYPE (exp);
1721 if (! flag_syntax_only)
1722 last_expr_value = expand_expr (exp,
1723 (expr_stmts_for_value
1724 ? NULL_RTX : const0_rtx),
1727 /* If all we do is reference a volatile value in memory,
1728 copy it to a register to be sure it is actually touched. */
1729 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1730 && TREE_THIS_VOLATILE (exp))
1732 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1734 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1735 copy_to_reg (last_expr_value);
1738 rtx lab = gen_label_rtx ();
1740 /* Compare the value with itself to reference it. */
1741 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1742 expand_expr (TYPE_SIZE (last_expr_type),
1743 NULL_RTX, VOIDmode, 0),
1745 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1746 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1751 /* If this expression is part of a ({...}) and is in memory, we may have
1752 to preserve temporaries. */
1753 preserve_temp_slots (last_expr_value);
1755 /* Free any temporaries used to evaluate this expression. Any temporary
1756 used as a result of this expression will already have been preserved
1763 /* Warn if EXP contains any computations whose results are not used.
1764 Return 1 if a warning is printed; 0 otherwise. */
1767 warn_if_unused_value (exp)
1770 if (TREE_USED (exp))
1773 switch (TREE_CODE (exp))
1775 case PREINCREMENT_EXPR:
1776 case POSTINCREMENT_EXPR:
1777 case PREDECREMENT_EXPR:
1778 case POSTDECREMENT_EXPR:
1783 case METHOD_CALL_EXPR:
1785 case WITH_CLEANUP_EXPR:
1787 /* We don't warn about COND_EXPR because it may be a useful
1788 construct if either arm contains a side effect. */
1793 /* For a binding, warn if no side effect within it. */
1794 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1797 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1799 case TRUTH_ORIF_EXPR:
1800 case TRUTH_ANDIF_EXPR:
1801 /* In && or ||, warn if 2nd operand has no side effect. */
1802 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1805 if (TREE_NO_UNUSED_WARNING (exp))
1807 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1809 /* Let people do `(foo (), 0)' without a warning. */
1810 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1812 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1816 case NON_LVALUE_EXPR:
1817 /* Don't warn about values cast to void. */
1818 if (TREE_TYPE (exp) == void_type_node)
1820 /* Don't warn about conversions not explicit in the user's program. */
1821 if (TREE_NO_UNUSED_WARNING (exp))
1823 /* Assignment to a cast usually results in a cast of a modify.
1824 Don't complain about that. There can be an arbitrary number of
1825 casts before the modify, so we must loop until we find the first
1826 non-cast expression and then test to see if that is a modify. */
1828 tree tem = TREE_OPERAND (exp, 0);
1830 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1831 tem = TREE_OPERAND (tem, 0);
1833 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1834 || TREE_CODE (tem) == CALL_EXPR)
1840 /* Don't warn about automatic dereferencing of references, since
1841 the user cannot control it. */
1842 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1843 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1844 /* ... fall through ... */
1847 /* Referencing a volatile value is a side effect, so don't warn. */
1848 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1849 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1850 && TREE_THIS_VOLATILE (exp))
1853 warning_with_file_and_line (emit_filename, emit_lineno,
1854 "value computed is not used");
1859 /* Clear out the memory of the last expression evaluated. */
1867 /* Begin a statement which will return a value.
1868 Return the RTL_EXPR for this statement expr.
1869 The caller must save that value and pass it to expand_end_stmt_expr. */
1872 expand_start_stmt_expr ()
1877 /* When generating bytecode just note down the stack depth */
1878 if (output_bytecode)
1879 return (build_int_2 (stack_depth, 0));
1881 /* Make the RTL_EXPR node temporary, not momentary,
1882 so that rtl_expr_chain doesn't become garbage. */
1883 momentary = suspend_momentary ();
1884 t = make_node (RTL_EXPR);
1885 resume_momentary (momentary);
1886 do_pending_stack_adjust ();
1887 start_sequence_for_rtl_expr (t);
1889 expr_stmts_for_value++;
1893 /* Restore the previous state at the end of a statement that returns a value.
1894 Returns a tree node representing the statement's value and the
1895 insns to compute the value.
1897 The nodes of that expression have been freed by now, so we cannot use them.
1898 But we don't want to do that anyway; the expression has already been
1899 evaluated and now we just want to use the value. So generate a RTL_EXPR
1900 with the proper type and RTL value.
1902 If the last substatement was not an expression,
1903 return something with type `void'. */
1906 expand_end_stmt_expr (t)
1909 if (output_bytecode)
1915 /* At this point, all expressions have been evaluated in order.
1916 However, all expression values have been popped when evaluated,
1917 which means we have to recover the last expression value. This is
1918 the last value removed by means of a `drop' instruction. Instead
1919 of adding code to inhibit dropping the last expression value, it
1920 is here recovered by undoing the `drop'. Since `drop' is
1921 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1924 bc_adjust_stack (-1);
1926 if (!last_expr_type)
1927 last_expr_type = void_type_node;
1929 t = make_node (RTL_EXPR);
1930 TREE_TYPE (t) = last_expr_type;
1931 RTL_EXPR_RTL (t) = NULL;
1932 RTL_EXPR_SEQUENCE (t) = NULL;
1934 /* Don't consider deleting this expr or containing exprs at tree level. */
1935 TREE_THIS_VOLATILE (t) = 1;
1943 if (last_expr_type == 0)
1945 last_expr_type = void_type_node;
1946 last_expr_value = const0_rtx;
1948 else if (last_expr_value == 0)
1949 /* There are some cases where this can happen, such as when the
1950 statement is void type. */
1951 last_expr_value = const0_rtx;
1952 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1953 /* Remove any possible QUEUED. */
1954 last_expr_value = protect_from_queue (last_expr_value, 0);
1958 TREE_TYPE (t) = last_expr_type;
1959 RTL_EXPR_RTL (t) = last_expr_value;
1960 RTL_EXPR_SEQUENCE (t) = get_insns ();
1962 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1966 /* Don't consider deleting this expr or containing exprs at tree level. */
1967 TREE_SIDE_EFFECTS (t) = 1;
1968 /* Propagate volatility of the actual RTL expr. */
1969 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1972 expr_stmts_for_value--;
1977 /* Generate RTL for the start of an if-then. COND is the expression
1978 whose truth should be tested.
1980 If EXITFLAG is nonzero, this conditional is visible to
1981 `exit_something'. */
1984 expand_start_cond (cond, exitflag)
1988 struct nesting *thiscond = ALLOC_NESTING ();
1990 /* Make an entry on cond_stack for the cond we are entering. */
1992 thiscond->next = cond_stack;
1993 thiscond->all = nesting_stack;
1994 thiscond->depth = ++nesting_depth;
1995 thiscond->data.cond.next_label = gen_label_rtx ();
1996 /* Before we encounter an `else', we don't need a separate exit label
1997 unless there are supposed to be exit statements
1998 to exit this conditional. */
1999 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2000 thiscond->data.cond.endif_label = thiscond->exit_label;
2001 cond_stack = thiscond;
2002 nesting_stack = thiscond;
2004 if (output_bytecode)
2005 bc_expand_start_cond (cond, exitflag);
2007 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2010 /* Generate RTL between then-clause and the elseif-clause
2011 of an if-then-elseif-.... */
2014 expand_start_elseif (cond)
2017 if (cond_stack->data.cond.endif_label == 0)
2018 cond_stack->data.cond.endif_label = gen_label_rtx ();
2019 emit_jump (cond_stack->data.cond.endif_label);
2020 emit_label (cond_stack->data.cond.next_label);
2021 cond_stack->data.cond.next_label = gen_label_rtx ();
2022 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2025 /* Generate RTL between the then-clause and the else-clause
2026 of an if-then-else. */
2029 expand_start_else ()
2031 if (cond_stack->data.cond.endif_label == 0)
2032 cond_stack->data.cond.endif_label = gen_label_rtx ();
2034 if (output_bytecode)
2036 bc_expand_start_else ();
2040 emit_jump (cond_stack->data.cond.endif_label);
2041 emit_label (cond_stack->data.cond.next_label);
2042 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2045 /* After calling expand_start_else, turn this "else" into an "else if"
2046 by providing another condition. */
2049 expand_elseif (cond)
2052 cond_stack->data.cond.next_label = gen_label_rtx ();
2053 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2056 /* Generate RTL for the end of an if-then.
2057 Pop the record for it off of cond_stack. */
2062 struct nesting *thiscond = cond_stack;
2064 if (output_bytecode)
2065 bc_expand_end_cond ();
2068 do_pending_stack_adjust ();
2069 if (thiscond->data.cond.next_label)
2070 emit_label (thiscond->data.cond.next_label);
2071 if (thiscond->data.cond.endif_label)
2072 emit_label (thiscond->data.cond.endif_label);
2075 POPSTACK (cond_stack);
2080 /* Generate code for the start of an if-then. COND is the expression
2081 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2082 is to be visible to exit_something. It is assumed that the caller
2083 has pushed the previous context on the cond stack. */
2086 bc_expand_start_cond (cond, exitflag)
2090 struct nesting *thiscond = cond_stack;
2092 thiscond->data.case_stmt.nominal_type = cond;
2094 thiscond->exit_label = gen_label_rtx ();
2095 bc_expand_expr (cond);
2096 bc_emit_bytecode (xjumpifnot);
2097 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2099 #ifdef DEBUG_PRINT_CODE
2100 fputc ('\n', stderr);
2104 /* Generate the label for the end of an if with
2108 bc_expand_end_cond ()
2110 struct nesting *thiscond = cond_stack;
2112 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2115 /* Generate code for the start of the else- clause of
2119 bc_expand_start_else ()
2121 struct nesting *thiscond = cond_stack;
2123 thiscond->data.cond.endif_label = thiscond->exit_label;
2124 thiscond->exit_label = gen_label_rtx ();
2125 bc_emit_bytecode (jump);
2126 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2128 #ifdef DEBUG_PRINT_CODE
2129 fputc ('\n', stderr);
2132 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2135 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2136 loop should be exited by `exit_something'. This is a loop for which
2137 `expand_continue' will jump to the top of the loop.
2139 Make an entry on loop_stack to record the labels associated with
2143 expand_start_loop (exit_flag)
2146 register struct nesting *thisloop = ALLOC_NESTING ();
2148 /* Make an entry on loop_stack for the loop we are entering. */
2150 thisloop->next = loop_stack;
2151 thisloop->all = nesting_stack;
2152 thisloop->depth = ++nesting_depth;
2153 thisloop->data.loop.start_label = gen_label_rtx ();
2154 thisloop->data.loop.end_label = gen_label_rtx ();
2155 thisloop->data.loop.alt_end_label = 0;
2156 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2157 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2158 loop_stack = thisloop;
2159 nesting_stack = thisloop;
2161 if (output_bytecode)
2163 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2167 do_pending_stack_adjust ();
2169 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2170 emit_label (thisloop->data.loop.start_label);
2175 /* Like expand_start_loop but for a loop where the continuation point
2176 (for expand_continue_loop) will be specified explicitly. */
2179 expand_start_loop_continue_elsewhere (exit_flag)
2182 struct nesting *thisloop = expand_start_loop (exit_flag);
2183 loop_stack->data.loop.continue_label = gen_label_rtx ();
2187 /* Specify the continuation point for a loop started with
2188 expand_start_loop_continue_elsewhere.
2189 Use this at the point in the code to which a continue statement
2193 expand_loop_continue_here ()
2195 if (output_bytecode)
2197 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2200 do_pending_stack_adjust ();
2201 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2202 emit_label (loop_stack->data.loop.continue_label);
2208 bc_expand_end_loop ()
2210 struct nesting *thisloop = loop_stack;
2212 bc_emit_bytecode (jump);
2213 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2215 #ifdef DEBUG_PRINT_CODE
2216 fputc ('\n', stderr);
2219 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2220 POPSTACK (loop_stack);
2225 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2226 Pop the block off of loop_stack. */
2232 register rtx start_label;
2233 rtx last_test_insn = 0;
2236 if (output_bytecode)
2238 bc_expand_end_loop ();
2242 insn = get_last_insn ();
2243 start_label = loop_stack->data.loop.start_label;
2245 /* Mark the continue-point at the top of the loop if none elsewhere. */
2246 if (start_label == loop_stack->data.loop.continue_label)
2247 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2249 do_pending_stack_adjust ();
2251 /* If optimizing, perhaps reorder the loop. If the loop
2252 starts with a conditional exit, roll that to the end
2253 where it will optimize together with the jump back.
2255 We look for the last conditional branch to the exit that we encounter
2256 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2257 branch to the exit first, use it.
2259 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2260 because moving them is not valid. */
2264 ! (GET_CODE (insn) == JUMP_INSN
2265 && GET_CODE (PATTERN (insn)) == SET
2266 && SET_DEST (PATTERN (insn)) == pc_rtx
2267 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2269 /* Scan insns from the top of the loop looking for a qualified
2270 conditional exit. */
2271 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2272 insn = NEXT_INSN (insn))
2274 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2277 if (GET_CODE (insn) == NOTE
2278 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2279 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2282 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2285 if (last_test_insn && num_insns > 30)
2288 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2289 && SET_DEST (PATTERN (insn)) == pc_rtx
2290 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2291 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2292 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2293 == loop_stack->data.loop.end_label)
2294 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2295 == loop_stack->data.loop.alt_end_label)))
2296 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2297 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2298 == loop_stack->data.loop.end_label)
2299 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2300 == loop_stack->data.loop.alt_end_label)))))
2301 last_test_insn = insn;
2303 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2304 && GET_CODE (PATTERN (insn)) == SET
2305 && SET_DEST (PATTERN (insn)) == pc_rtx
2306 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2307 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2308 == loop_stack->data.loop.end_label)
2309 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2310 == loop_stack->data.loop.alt_end_label)))
2311 /* Include BARRIER. */
2312 last_test_insn = NEXT_INSN (insn);
2315 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2317 /* We found one. Move everything from there up
2318 to the end of the loop, and add a jump into the loop
2319 to jump to there. */
2320 register rtx newstart_label = gen_label_rtx ();
2321 register rtx start_move = start_label;
2323 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2324 then we want to move this note also. */
2325 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2326 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2327 == NOTE_INSN_LOOP_CONT))
2328 start_move = PREV_INSN (start_move);
2330 emit_label_after (newstart_label, PREV_INSN (start_move));
2331 reorder_insns (start_move, last_test_insn, get_last_insn ());
2332 emit_jump_insn_after (gen_jump (start_label),
2333 PREV_INSN (newstart_label));
2334 emit_barrier_after (PREV_INSN (newstart_label));
2335 start_label = newstart_label;
2339 emit_jump (start_label);
2340 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2341 emit_label (loop_stack->data.loop.end_label);
2343 POPSTACK (loop_stack);
2348 /* Generate a jump to the current loop's continue-point.
2349 This is usually the top of the loop, but may be specified
2350 explicitly elsewhere. If not currently inside a loop,
2351 return 0 and do nothing; caller will print an error message. */
2354 expand_continue_loop (whichloop)
2355 struct nesting *whichloop;
2359 whichloop = loop_stack;
2362 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2367 /* Generate a jump to exit the current loop. If not currently inside a loop,
2368 return 0 and do nothing; caller will print an error message. */
2371 expand_exit_loop (whichloop)
2372 struct nesting *whichloop;
2376 whichloop = loop_stack;
2379 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2383 /* Generate a conditional jump to exit the current loop if COND
2384 evaluates to zero. If not currently inside a loop,
2385 return 0 and do nothing; caller will print an error message. */
2388 expand_exit_loop_if_false (whichloop, cond)
2389 struct nesting *whichloop;
2394 whichloop = loop_stack;
2397 if (output_bytecode)
2399 bc_expand_expr (cond);
2400 bc_expand_goto_internal (xjumpifnot,
2401 BYTECODE_BC_LABEL (whichloop->exit_label),
2406 /* In order to handle fixups, we actually create a conditional jump
2407 around a unconditional branch to exit the loop. If fixups are
2408 necessary, they go before the unconditional branch. */
2410 rtx label = gen_label_rtx ();
2413 do_jump (cond, NULL_RTX, label);
2414 last_insn = get_last_insn ();
2415 if (GET_CODE (last_insn) == CODE_LABEL)
2416 whichloop->data.loop.alt_end_label = last_insn;
2417 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2425 /* Return non-zero if we should preserve sub-expressions as separate
2426 pseudos. We never do so if we aren't optimizing. We always do so
2427 if -fexpensive-optimizations.
2429 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2430 the loop may still be a small one. */
2433 preserve_subexpressions_p ()
2437 if (flag_expensive_optimizations)
2440 if (optimize == 0 || loop_stack == 0)
2443 insn = get_last_insn_anywhere ();
2446 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2447 < n_non_fixed_regs * 3));
2451 /* Generate a jump to exit the current loop, conditional, binding contour
2452 or case statement. Not all such constructs are visible to this function,
2453 only those started with EXIT_FLAG nonzero. Individual languages use
2454 the EXIT_FLAG parameter to control which kinds of constructs you can
2457 If not currently inside anything that can be exited,
2458 return 0 and do nothing; caller will print an error message. */
2461 expand_exit_something ()
2465 for (n = nesting_stack; n; n = n->all)
2466 if (n->exit_label != 0)
2468 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2475 /* Generate RTL to return from the current function, with no value.
2476 (That is, we do not do anything about returning any value.) */
2479 expand_null_return ()
2481 struct nesting *block = block_stack;
2484 if (output_bytecode)
2486 bc_emit_instruction (ret);
2490 /* Does any pending block have cleanups? */
2492 while (block && block->data.block.cleanups == 0)
2493 block = block->next;
2495 /* If yes, use a goto to return, since that runs cleanups. */
2497 expand_null_return_1 (last_insn, block != 0);
2500 /* Generate RTL to return from the current function, with value VAL. */
2503 expand_value_return (val)
2506 struct nesting *block = block_stack;
2507 rtx last_insn = get_last_insn ();
2508 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2510 /* Copy the value to the return location
2511 unless it's already there. */
2513 if (return_reg != val)
2515 #ifdef PROMOTE_FUNCTION_RETURN
2516 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2517 int unsignedp = TREE_UNSIGNED (type);
2518 enum machine_mode mode
2519 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2522 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2523 convert_move (return_reg, val, unsignedp);
2526 emit_move_insn (return_reg, val);
2528 if (GET_CODE (return_reg) == REG
2529 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2530 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2532 /* Does any pending block have cleanups? */
2534 while (block && block->data.block.cleanups == 0)
2535 block = block->next;
2537 /* If yes, use a goto to return, since that runs cleanups.
2538 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2540 expand_null_return_1 (last_insn, block != 0);
2543 /* Output a return with no value. If LAST_INSN is nonzero,
2544 pretend that the return takes place after LAST_INSN.
2545 If USE_GOTO is nonzero then don't use a return instruction;
2546 go to the return label instead. This causes any cleanups
2547 of pending blocks to be executed normally. */
2550 expand_null_return_1 (last_insn, use_goto)
2554 rtx end_label = cleanup_label ? cleanup_label : return_label;
2556 clear_pending_stack_adjust ();
2557 do_pending_stack_adjust ();
2560 /* PCC-struct return always uses an epilogue. */
2561 if (current_function_returns_pcc_struct || use_goto)
2564 end_label = return_label = gen_label_rtx ();
2565 expand_goto_internal (NULL_TREE, end_label, last_insn);
2569 /* Otherwise output a simple return-insn if one is available,
2570 unless it won't do the job. */
2572 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2574 emit_jump_insn (gen_return ());
2580 /* Otherwise jump to the epilogue. */
2581 expand_goto_internal (NULL_TREE, end_label, last_insn);
2584 /* Generate RTL to evaluate the expression RETVAL and return it
2585 from the current function. */
2588 expand_return (retval)
2591 /* If there are any cleanups to be performed, then they will
2592 be inserted following LAST_INSN. It is desirable
2593 that the last_insn, for such purposes, should be the
2594 last insn before computing the return value. Otherwise, cleanups
2595 which call functions can clobber the return value. */
2596 /* ??? rms: I think that is erroneous, because in C++ it would
2597 run destructors on variables that might be used in the subsequent
2598 computation of the return value. */
2600 register rtx val = 0;
2604 struct nesting *block;
2606 /* Bytecode returns are quite simple, just leave the result on the
2607 arithmetic stack. */
2608 if (output_bytecode)
2610 bc_expand_expr (retval);
2611 bc_emit_instruction (ret);
2615 /* If function wants no value, give it none. */
2616 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2618 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2620 expand_null_return ();
2624 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2625 /* This is not sufficient. We also need to watch for cleanups of the
2626 expression we are about to expand. Unfortunately, we cannot know
2627 if it has cleanups until we expand it, and we want to change how we
2628 expand it depending upon if we need cleanups. We can't win. */
2630 cleanups = any_pending_cleanups (1);
2635 if (TREE_CODE (retval) == RESULT_DECL)
2636 retval_rhs = retval;
2637 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2638 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2639 retval_rhs = TREE_OPERAND (retval, 1);
2640 else if (TREE_TYPE (retval) == void_type_node)
2641 /* Recognize tail-recursive call to void function. */
2642 retval_rhs = retval;
2644 retval_rhs = NULL_TREE;
2646 /* Only use `last_insn' if there are cleanups which must be run. */
2647 if (cleanups || cleanup_label != 0)
2648 last_insn = get_last_insn ();
2650 /* Distribute return down conditional expr if either of the sides
2651 may involve tail recursion (see test below). This enhances the number
2652 of tail recursions we see. Don't do this always since it can produce
2653 sub-optimal code in some cases and we distribute assignments into
2654 conditional expressions when it would help. */
2656 if (optimize && retval_rhs != 0
2657 && frame_offset == 0
2658 && TREE_CODE (retval_rhs) == COND_EXPR
2659 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2660 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2662 rtx label = gen_label_rtx ();
2665 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2666 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2667 DECL_RESULT (current_function_decl),
2668 TREE_OPERAND (retval_rhs, 1));
2669 TREE_SIDE_EFFECTS (expr) = 1;
2670 expand_return (expr);
2673 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2674 DECL_RESULT (current_function_decl),
2675 TREE_OPERAND (retval_rhs, 2));
2676 TREE_SIDE_EFFECTS (expr) = 1;
2677 expand_return (expr);
2681 /* For tail-recursive call to current function,
2682 just jump back to the beginning.
2683 It's unsafe if any auto variable in this function
2684 has its address taken; for simplicity,
2685 require stack frame to be empty. */
2686 if (optimize && retval_rhs != 0
2687 && frame_offset == 0
2688 && TREE_CODE (retval_rhs) == CALL_EXPR
2689 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2690 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2691 /* Finish checking validity, and if valid emit code
2692 to set the argument variables for the new call. */
2693 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2694 DECL_ARGUMENTS (current_function_decl)))
2696 if (tail_recursion_label == 0)
2698 tail_recursion_label = gen_label_rtx ();
2699 emit_label_after (tail_recursion_label,
2700 tail_recursion_reentry);
2703 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2708 /* This optimization is safe if there are local cleanups
2709 because expand_null_return takes care of them.
2710 ??? I think it should also be safe when there is a cleanup label,
2711 because expand_null_return takes care of them, too.
2712 Any reason why not? */
2713 if (HAVE_return && cleanup_label == 0
2714 && ! current_function_returns_pcc_struct
2715 && BRANCH_COST <= 1)
2717 /* If this is return x == y; then generate
2718 if (x == y) return 1; else return 0;
2719 if we can do it with explicit return insns and
2720 branches are cheap. */
2722 switch (TREE_CODE (retval_rhs))
2730 case TRUTH_ANDIF_EXPR:
2731 case TRUTH_ORIF_EXPR:
2732 case TRUTH_AND_EXPR:
2734 case TRUTH_NOT_EXPR:
2735 case TRUTH_XOR_EXPR:
2736 op0 = gen_label_rtx ();
2737 jumpifnot (retval_rhs, op0);
2738 expand_value_return (const1_rtx);
2740 expand_value_return (const0_rtx);
2744 #endif /* HAVE_return */
2746 /* If the result is an aggregate that is being returned in one (or more)
2747 registers, load the registers here. The compiler currently can't handle
2748 copying a BLKmode value into registers. We could put this code in a
2749 more general area (for use by everyone instead of just function
2750 call/return), but until this feature is generally usable it is kept here
2751 (and in expand_call). The value must go into a pseudo in case there
2752 are cleanups that will clobber the real return register. */
2755 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2756 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2758 int i, bitpos, xbitpos;
2759 int big_endian_correction = 0;
2760 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2761 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2762 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2763 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2764 rtx result_reg, src, dst;
2765 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2766 enum machine_mode tmpmode, result_reg_mode;
2768 /* Structures whose size is not a multiple of a word are aligned
2769 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2770 machine, this means we must skip the empty high order bytes when
2771 calculating the bit offset. */
2772 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2773 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2776 /* Copy the structure BITSIZE bits at a time. */
2777 for (bitpos = 0, xbitpos = big_endian_correction;
2778 bitpos < bytes * BITS_PER_UNIT;
2779 bitpos += bitsize, xbitpos += bitsize)
2781 /* We need a new destination pseudo each time xbitpos is
2782 on a word boundary and when xbitpos == big_endian_correction
2783 (the first time through). */
2784 if (xbitpos % BITS_PER_WORD == 0
2785 || xbitpos == big_endian_correction)
2787 /* Generate an appropriate register. */
2788 dst = gen_reg_rtx (word_mode);
2789 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2791 /* Clobber the destination before we move anything into it. */
2792 emit_insn (gen_rtx (CLOBBER, VOIDmode, dst));
2795 /* We need a new source operand each time bitpos is on a word
2797 if (bitpos % BITS_PER_WORD == 0)
2798 src = operand_subword_force (result_val,
2799 bitpos / BITS_PER_WORD,
2802 /* Use bitpos for the source extraction (left justified) and
2803 xbitpos for the destination store (right justified). */
2804 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2805 extract_bit_field (src, bitsize,
2806 bitpos % BITS_PER_WORD, 1,
2807 NULL_RTX, word_mode,
2809 bitsize / BITS_PER_UNIT,
2811 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2814 /* Find the smallest integer mode large enough to hold the
2815 entire structure and use that mode instead of BLKmode
2816 on the USE insn for the return register. */
2817 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2818 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2819 tmpmode != MAX_MACHINE_MODE;
2820 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2822 /* Have we found a large enough mode? */
2823 if (GET_MODE_SIZE (tmpmode) >= bytes)
2827 /* No suitable mode found. */
2828 if (tmpmode == MAX_MACHINE_MODE)
2831 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2833 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2834 result_reg_mode = word_mode;
2836 result_reg_mode = tmpmode;
2837 result_reg = gen_reg_rtx (result_reg_mode);
2839 /* Now that the value is in pseudos, copy it to the result reg(s). */
2842 for (i = 0; i < n_regs; i++)
2843 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2846 if (tmpmode != result_reg_mode)
2847 result_reg = gen_lowpart (tmpmode, result_reg);
2849 expand_value_return (result_reg);
2853 && TREE_TYPE (retval_rhs) != void_type_node
2854 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2856 /* Calculate the return value into a pseudo reg. */
2857 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2859 /* All temporaries have now been used. */
2861 /* Return the calculated value, doing cleanups first. */
2862 expand_value_return (val);
2866 /* No cleanups or no hard reg used;
2867 calculate value into hard return reg. */
2868 expand_expr (retval, const0_rtx, VOIDmode, 0);
2871 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2875 /* Return 1 if the end of the generated RTX is not a barrier.
2876 This means code already compiled can drop through. */
2879 drop_through_at_end_p ()
2881 rtx insn = get_last_insn ();
2882 while (insn && GET_CODE (insn) == NOTE)
2883 insn = PREV_INSN (insn);
2884 return insn && GET_CODE (insn) != BARRIER;
2887 /* Emit code to alter this function's formal parms for a tail-recursive call.
2888 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2889 FORMALS is the chain of decls of formals.
2890 Return 1 if this can be done;
2891 otherwise return 0 and do not emit any code. */
2894 tail_recursion_args (actuals, formals)
2895 tree actuals, formals;
2897 register tree a = actuals, f = formals;
2899 register rtx *argvec;
2901 /* Check that number and types of actuals are compatible
2902 with the formals. This is not always true in valid C code.
2903 Also check that no formal needs to be addressable
2904 and that all formals are scalars. */
2906 /* Also count the args. */
2908 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2910 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
2911 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
2913 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2916 if (a != 0 || f != 0)
2919 /* Compute all the actuals. */
2921 argvec = (rtx *) alloca (i * sizeof (rtx));
2923 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2924 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2926 /* Find which actual values refer to current values of previous formals.
2927 Copy each of them now, before any formal is changed. */
2929 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2933 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2934 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2935 { copy = 1; break; }
2937 argvec[i] = copy_to_reg (argvec[i]);
2940 /* Store the values of the actuals into the formals. */
2942 for (f = formals, a = actuals, i = 0; f;
2943 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2945 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2946 emit_move_insn (DECL_RTL (f), argvec[i]);
2948 convert_move (DECL_RTL (f), argvec[i],
2949 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2956 /* Generate the RTL code for entering a binding contour.
2957 The variables are declared one by one, by calls to `expand_decl'.
2959 EXIT_FLAG is nonzero if this construct should be visible to
2960 `exit_something'. */
2963 expand_start_bindings (exit_flag)
2966 struct nesting *thisblock = ALLOC_NESTING ();
2967 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2969 /* Make an entry on block_stack for the block we are entering. */
2971 thisblock->next = block_stack;
2972 thisblock->all = nesting_stack;
2973 thisblock->depth = ++nesting_depth;
2974 thisblock->data.block.stack_level = 0;
2975 thisblock->data.block.cleanups = 0;
2976 thisblock->data.block.function_call_count = 0;
2980 if (block_stack->data.block.cleanups == NULL_TREE
2981 && (block_stack->data.block.outer_cleanups == NULL_TREE
2982 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2983 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2985 thisblock->data.block.outer_cleanups
2986 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2987 block_stack->data.block.outer_cleanups);
2990 thisblock->data.block.outer_cleanups = 0;
2994 && !(block_stack->data.block.cleanups == NULL_TREE
2995 && block_stack->data.block.outer_cleanups == NULL_TREE))
2996 thisblock->data.block.outer_cleanups
2997 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2998 block_stack->data.block.outer_cleanups);
3000 thisblock->data.block.outer_cleanups = 0;
3002 thisblock->data.block.label_chain = 0;
3003 thisblock->data.block.innermost_stack_block = stack_block_stack;
3004 thisblock->data.block.first_insn = note;
3005 thisblock->data.block.block_start_count = ++block_start_count;
3006 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3007 block_stack = thisblock;
3008 nesting_stack = thisblock;
3010 if (!output_bytecode)
3012 /* Make a new level for allocating stack slots. */
3017 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3018 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3022 remember_end_note (block)
3023 register tree block;
3025 BLOCK_END_NOTE (block) = last_block_end_note;
3026 last_block_end_note = NULL_RTX;
3029 /* Generate RTL code to terminate a binding contour.
3030 VARS is the chain of VAR_DECL nodes
3031 for the variables bound in this contour.
3032 MARK_ENDS is nonzero if we should put a note at the beginning
3033 and end of this binding contour.
3035 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3036 (That is true automatically if the contour has a saved stack level.) */
3039 expand_end_bindings (vars, mark_ends, dont_jump_in)
3044 register struct nesting *thisblock = block_stack;
3047 if (output_bytecode)
3049 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
3054 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3055 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
3056 && ! DECL_IN_SYSTEM_HEADER (decl))
3057 warning_with_decl (decl, "unused variable `%s'");
3059 if (thisblock->exit_label)
3061 do_pending_stack_adjust ();
3062 emit_label (thisblock->exit_label);
3065 /* If necessary, make a handler for nonlocal gotos taking
3066 place in the function calls in this block. */
3067 if (function_call_count != thisblock->data.block.function_call_count
3069 /* Make handler for outermost block
3070 if there were any nonlocal gotos to this function. */
3071 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3072 /* Make handler for inner block if it has something
3073 special to do when you jump out of it. */
3074 : (thisblock->data.block.cleanups != 0
3075 || thisblock->data.block.stack_level != 0)))
3078 rtx afterward = gen_label_rtx ();
3079 rtx handler_label = gen_label_rtx ();
3080 rtx save_receiver = gen_reg_rtx (Pmode);
3083 /* Don't let jump_optimize delete the handler. */
3084 LABEL_PRESERVE_P (handler_label) = 1;
3086 /* Record the handler address in the stack slot for that purpose,
3087 during this block, saving and restoring the outer value. */
3088 if (thisblock->next != 0)
3090 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3093 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3094 insns = get_insns ();
3096 emit_insns_before (insns, thisblock->data.block.first_insn);
3100 emit_move_insn (nonlocal_goto_handler_slot,
3101 gen_rtx (LABEL_REF, Pmode, handler_label));
3102 insns = get_insns ();
3104 emit_insns_before (insns, thisblock->data.block.first_insn);
3106 /* Jump around the handler; it runs only when specially invoked. */
3107 emit_jump (afterward);
3108 emit_label (handler_label);
3110 #ifdef HAVE_nonlocal_goto
3111 if (! HAVE_nonlocal_goto)
3113 /* First adjust our frame pointer to its actual value. It was
3114 previously set to the start of the virtual area corresponding to
3115 the stacked variables when we branched here and now needs to be
3116 adjusted to the actual hardware fp value.
3118 Assignments are to virtual registers are converted by
3119 instantiate_virtual_regs into the corresponding assignment
3120 to the underlying register (fp in this case) that makes
3121 the original assignment true.
3122 So the following insn will actually be
3123 decrementing fp by STARTING_FRAME_OFFSET. */
3124 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3126 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3127 if (fixed_regs[ARG_POINTER_REGNUM])
3129 #ifdef ELIMINABLE_REGS
3130 /* If the argument pointer can be eliminated in favor of the
3131 frame pointer, we don't need to restore it. We assume here
3132 that if such an elimination is present, it can always be used.
3133 This is the case on all known machines; if we don't make this
3134 assumption, we do unnecessary saving on many machines. */
3135 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3138 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3139 if (elim_regs[i].from == ARG_POINTER_REGNUM
3140 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3143 if (i == sizeof elim_regs / sizeof elim_regs [0])
3146 /* Now restore our arg pointer from the address at which it
3147 was saved in our stack frame.
3148 If there hasn't be space allocated for it yet, make
3150 if (arg_pointer_save_area == 0)
3151 arg_pointer_save_area
3152 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3153 emit_move_insn (virtual_incoming_args_rtx,
3154 /* We need a pseudo here, or else
3155 instantiate_virtual_regs_1 complains. */
3156 copy_to_reg (arg_pointer_save_area));
3161 /* The handler expects the desired label address in the static chain
3162 register. It tests the address and does an appropriate jump
3163 to whatever label is desired. */
3164 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3165 /* Skip any labels we shouldn't be able to jump to from here. */
3166 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3168 rtx not_this = gen_label_rtx ();
3169 rtx this = gen_label_rtx ();
3170 do_jump_if_equal (static_chain_rtx,
3171 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3173 emit_jump (not_this);
3175 expand_goto (TREE_VALUE (link));
3176 emit_label (not_this);
3178 /* If label is not recognized, abort. */
3179 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3182 emit_label (afterward);
3185 /* Don't allow jumping into a block that has cleanups or a stack level. */
3187 || thisblock->data.block.stack_level != 0
3188 || thisblock->data.block.cleanups != 0)
3190 struct label_chain *chain;
3192 /* Any labels in this block are no longer valid to go to.
3193 Mark them to cause an error message. */
3194 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3196 DECL_TOO_LATE (chain->label) = 1;
3197 /* If any goto without a fixup came to this label,
3198 that must be an error, because gotos without fixups
3199 come from outside all saved stack-levels and all cleanups. */
3200 if (TREE_ADDRESSABLE (chain->label))
3201 error_with_decl (chain->label,
3202 "label `%s' used before containing binding contour");
3206 /* Restore stack level in effect before the block
3207 (only if variable-size objects allocated). */
3208 /* Perform any cleanups associated with the block. */
3210 if (thisblock->data.block.stack_level != 0
3211 || thisblock->data.block.cleanups != 0)
3213 /* Only clean up here if this point can actually be reached. */
3214 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3216 /* Don't let cleanups affect ({...}) constructs. */
3217 int old_expr_stmts_for_value = expr_stmts_for_value;
3218 rtx old_last_expr_value = last_expr_value;
3219 tree old_last_expr_type = last_expr_type;
3220 expr_stmts_for_value = 0;
3222 /* Do the cleanups. */
3223 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3225 do_pending_stack_adjust ();
3227 expr_stmts_for_value = old_expr_stmts_for_value;
3228 last_expr_value = old_last_expr_value;
3229 last_expr_type = old_last_expr_type;
3231 /* Restore the stack level. */
3233 if (reachable && thisblock->data.block.stack_level != 0)
3235 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3236 thisblock->data.block.stack_level, NULL_RTX);
3237 if (nonlocal_goto_handler_slot != 0)
3238 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3242 /* Any gotos out of this block must also do these things.
3243 Also report any gotos with fixups that came to labels in this
3245 fixup_gotos (thisblock,
3246 thisblock->data.block.stack_level,
3247 thisblock->data.block.cleanups,
3248 thisblock->data.block.first_insn,
3252 /* Mark the beginning and end of the scope if requested.
3253 We do this now, after running cleanups on the variables
3254 just going out of scope, so they are in scope for their cleanups. */
3257 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3259 /* Get rid of the beginning-mark if we don't make an end-mark. */
3260 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3262 /* If doing stupid register allocation, make sure lives of all
3263 register variables declared here extend thru end of scope. */
3266 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3268 rtx rtl = DECL_RTL (decl);
3269 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3273 /* Restore block_stack level for containing block. */
3275 stack_block_stack = thisblock->data.block.innermost_stack_block;
3276 POPSTACK (block_stack);
3278 /* Pop the stack slot nesting and free any slots at this level. */
3283 /* End a binding contour.
3284 VARS is the chain of VAR_DECL nodes for the variables bound
3285 in this contour. MARK_ENDS is nonzer if we should put a note
3286 at the beginning and end of this binding contour.
3287 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3291 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3296 struct nesting *thisbind = nesting_stack;
3300 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3301 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3302 warning_with_decl (decl, "unused variable `%s'");
3304 if (thisbind->exit_label)
3305 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3307 /* Pop block/bindings off stack */
3308 POPSTACK (block_stack);
3311 /* Generate RTL for the automatic variable declaration DECL.
3312 (Other kinds of declarations are simply ignored if seen here.) */
3318 struct nesting *thisblock = block_stack;
3321 if (output_bytecode)
3323 bc_expand_decl (decl, 0);
3327 type = TREE_TYPE (decl);
3329 /* Only automatic variables need any expansion done.
3330 Static and external variables, and external functions,
3331 will be handled by `assemble_variable' (called from finish_decl).
3332 TYPE_DECL and CONST_DECL require nothing.
3333 PARM_DECLs are handled in `assign_parms'. */
3335 if (TREE_CODE (decl) != VAR_DECL)
3337 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3340 /* Create the RTL representation for the variable. */
3342 if (type == error_mark_node)
3343 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3344 else if (DECL_SIZE (decl) == 0)
3345 /* Variable with incomplete type. */
3347 if (DECL_INITIAL (decl) == 0)
3348 /* Error message was already done; now avoid a crash. */
3349 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3351 /* An initializer is going to decide the size of this array.
3352 Until we know the size, represent its address with a reg. */
3353 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3354 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3356 else if (DECL_MODE (decl) != BLKmode
3357 /* If -ffloat-store, don't put explicit float vars
3359 && !(flag_float_store
3360 && TREE_CODE (type) == REAL_TYPE)
3361 && ! TREE_THIS_VOLATILE (decl)
3362 && ! TREE_ADDRESSABLE (decl)
3363 && (DECL_REGISTER (decl) || ! obey_regdecls))
3365 /* Automatic variable that can go in a register. */
3366 int unsignedp = TREE_UNSIGNED (type);
3367 enum machine_mode reg_mode
3368 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3370 if (TREE_CODE (type) == COMPLEX_TYPE)
3372 rtx realpart, imagpart;
3373 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3375 /* For a complex type variable, make a CONCAT of two pseudos
3376 so that the real and imaginary parts
3377 can be allocated separately. */
3378 realpart = gen_reg_rtx (partmode);
3379 REG_USERVAR_P (realpart) = 1;
3380 imagpart = gen_reg_rtx (partmode);
3381 REG_USERVAR_P (imagpart) = 1;
3382 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3386 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3387 if (TREE_CODE (type) == POINTER_TYPE)
3388 mark_reg_pointer (DECL_RTL (decl),
3389 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3391 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3394 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3396 /* Variable of fixed size that goes on the stack. */
3400 /* If we previously made RTL for this decl, it must be an array
3401 whose size was determined by the initializer.
3402 The old address was a register; set that register now
3403 to the proper address. */
3404 if (DECL_RTL (decl) != 0)
3406 if (GET_CODE (DECL_RTL (decl)) != MEM
3407 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3409 oldaddr = XEXP (DECL_RTL (decl), 0);
3413 = assign_stack_temp (DECL_MODE (decl),
3414 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3415 + BITS_PER_UNIT - 1)
3418 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3420 /* Set alignment we actually gave this decl. */
3421 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3422 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3426 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3427 if (addr != oldaddr)
3428 emit_move_insn (oldaddr, addr);
3431 /* If this is a memory ref that contains aggregate components,
3432 mark it as such for cse and loop optimize. */
3433 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3435 /* If this is in memory because of -ffloat-store,
3436 set the volatile bit, to prevent optimizations from
3437 undoing the effects. */
3438 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3439 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3443 /* Dynamic-size object: must push space on the stack. */
3447 /* Record the stack pointer on entry to block, if have
3448 not already done so. */
3449 if (thisblock->data.block.stack_level == 0)
3451 do_pending_stack_adjust ();
3452 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3453 &thisblock->data.block.stack_level,
3454 thisblock->data.block.first_insn);
3455 stack_block_stack = thisblock;
3458 /* Compute the variable's size, in bytes. */
3459 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3461 size_int (BITS_PER_UNIT)),
3462 NULL_RTX, VOIDmode, 0);
3465 /* Allocate space on the stack for the variable. */
3466 address = allocate_dynamic_stack_space (size, NULL_RTX,
3469 /* Reference the variable indirect through that rtx. */
3470 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3472 /* If this is a memory ref that contains aggregate components,
3473 mark it as such for cse and loop optimize. */
3474 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3476 /* Indicate the alignment we actually gave this variable. */
3477 #ifdef STACK_BOUNDARY
3478 DECL_ALIGN (decl) = STACK_BOUNDARY;
3480 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3484 if (TREE_THIS_VOLATILE (decl))
3485 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3486 #if 0 /* A variable is not necessarily unchanging
3487 just because it is const. RTX_UNCHANGING_P
3488 means no change in the function,
3489 not merely no change in the variable's scope.
3490 It is correct to set RTX_UNCHANGING_P if the variable's scope
3491 is the whole function. There's no convenient way to test that. */
3492 if (TREE_READONLY (decl))
3493 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3496 /* If doing stupid register allocation, make sure life of any
3497 register variable starts here, at the start of its scope. */
3500 use_variable (DECL_RTL (decl));
3504 /* Generate code for the automatic variable declaration DECL. For
3505 most variables this just means we give it a stack offset. The
3506 compiler sometimes emits cleanups without variables and we will
3507 have to deal with those too. */
3510 bc_expand_decl (decl, cleanup)
3518 /* A cleanup with no variable. */
3525 /* Only auto variables need any work. */
3526 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3529 type = TREE_TYPE (decl);
3531 if (type == error_mark_node)
3532 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3534 else if (DECL_SIZE (decl) == 0)
3536 /* Variable with incomplete type. The stack offset herein will be
3537 fixed later in expand_decl_init (). */
3538 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3540 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3542 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3546 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3549 /* Emit code to perform the initialization of a declaration DECL. */
3552 expand_decl_init (decl)
3555 int was_used = TREE_USED (decl);
3557 if (output_bytecode)
3559 bc_expand_decl_init (decl);
3563 /* If this is a CONST_DECL, we don't have to generate any code, but
3564 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3565 to be set while in the obstack containing the constant. If we don't
3566 do this, we can lose if we have functions nested three deep and the middle
3567 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3568 the innermost function is the first to expand that STRING_CST. */
3569 if (TREE_CODE (decl) == CONST_DECL)
3571 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3572 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3573 EXPAND_INITIALIZER);
3577 if (TREE_STATIC (decl))
3580 /* Compute and store the initial value now. */
3582 if (DECL_INITIAL (decl) == error_mark_node)
3584 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3585 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3586 || code == POINTER_TYPE)
3587 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3591 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3593 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3594 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3598 /* Don't let the initialization count as "using" the variable. */
3599 TREE_USED (decl) = was_used;
3601 /* Free any temporaries we made while initializing the decl. */
3602 preserve_temp_slots (NULL_RTX);
3606 /* Expand initialization for variable-sized types. Allocate array
3607 using newlocalSI and set local variable, which is a pointer to the
3611 bc_expand_variable_local_init (decl)
3614 /* Evaluate size expression and coerce to SI */
3615 bc_expand_expr (DECL_SIZE (decl));
3617 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3618 no coercion is necessary (?) */
3620 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3621 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3623 /* Emit code to allocate array */
3624 bc_emit_instruction (newlocalSI);
3626 /* Store array pointer in local variable. This is the only instance
3627 where we actually want the address of the pointer to the
3628 variable-size block, rather than the pointer itself. We avoid
3629 using expand_address() since that would cause the pointer to be
3630 pushed rather than its address. Hence the hard-coded reference;
3631 notice also that the variable is always local (no global
3632 variable-size type variables). */
3634 bc_load_localaddr (DECL_RTL (decl));
3635 bc_emit_instruction (storeP);
3639 /* Emit code to initialize a declaration. */
3642 bc_expand_decl_init (decl)
3645 int org_stack_depth;
3647 /* Statical initializers are handled elsewhere */
3649 if (TREE_STATIC (decl))
3652 /* Memory original stack depth */
3653 org_stack_depth = stack_depth;
3655 /* If the type is variable-size, we first create its space (we ASSUME
3656 it CAN'T be static). We do this regardless of whether there's an
3657 initializer assignment or not. */
3659 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3660 bc_expand_variable_local_init (decl);
3662 /* Expand initializer assignment */
3663 if (DECL_INITIAL (decl) == error_mark_node)
3665 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3667 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3668 || code == POINTER_TYPE)
3670 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3672 else if (DECL_INITIAL (decl))
3673 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3675 /* Restore stack depth */
3676 if (org_stack_depth > stack_depth)
3679 bc_adjust_stack (stack_depth - org_stack_depth);
3683 /* CLEANUP is an expression to be executed at exit from this binding contour;
3684 for example, in C++, it might call the destructor for this variable.
3686 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3687 either before or after calling `expand_decl_cleanup' but before compiling
3688 any subsequent expressions. This is because CLEANUP may be expanded
3689 more than once, on different branches of execution.
3690 For the same reason, CLEANUP may not contain a CALL_EXPR
3691 except as its topmost node--else `preexpand_calls' would get confused.
3693 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3694 that is not associated with any particular variable. */
3697 expand_decl_cleanup (decl, cleanup)
3700 struct nesting *thisblock = block_stack;
3702 /* Error if we are not in any block. */
3706 /* Record the cleanup if there is one. */
3710 thisblock->data.block.cleanups
3711 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3712 /* If this block has a cleanup, it belongs in stack_block_stack. */
3713 stack_block_stack = thisblock;
3714 (*interim_eh_hook) (NULL_TREE);
3719 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3720 DECL_ELTS is the list of elements that belong to DECL's type.
3721 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3724 expand_anon_union_decl (decl, cleanup, decl_elts)
3725 tree decl, cleanup, decl_elts;
3727 struct nesting *thisblock = block_stack;
3731 expand_decl_cleanup (decl, cleanup);
3732 x = DECL_RTL (decl);
3736 tree decl_elt = TREE_VALUE (decl_elts);
3737 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3738 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3740 /* Propagate the union's alignment to the elements. */
3741 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3743 /* If the element has BLKmode and the union doesn't, the union is
3744 aligned such that the element doesn't need to have BLKmode, so
3745 change the element's mode to the appropriate one for its size. */
3746 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3747 DECL_MODE (decl_elt) = mode
3748 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3751 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3752 instead create a new MEM rtx with the proper mode. */
3753 if (GET_CODE (x) == MEM)
3755 if (mode == GET_MODE (x))
3756 DECL_RTL (decl_elt) = x;
3759 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3760 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3761 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3764 else if (GET_CODE (x) == REG)
3766 if (mode == GET_MODE (x))
3767 DECL_RTL (decl_elt) = x;
3769 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3774 /* Record the cleanup if there is one. */
3777 thisblock->data.block.cleanups
3778 = temp_tree_cons (decl_elt, cleanup_elt,
3779 thisblock->data.block.cleanups);
3781 decl_elts = TREE_CHAIN (decl_elts);
3785 /* Expand a list of cleanups LIST.
3786 Elements may be expressions or may be nested lists.
3788 If DONT_DO is nonnull, then any list-element
3789 whose TREE_PURPOSE matches DONT_DO is omitted.
3790 This is sometimes used to avoid a cleanup associated with
3791 a value that is being returned out of the scope.
3793 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3794 goto and handle protection regions specially in that case.
3796 If REACHABLE, we emit code, otherwise just inform the exception handling
3797 code about this finalization. */
3800 expand_cleanups (list, dont_do, in_fixup, reachable)
3807 for (tail = list; tail; tail = TREE_CHAIN (tail))
3808 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3810 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3811 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3815 (*interim_eh_hook) (TREE_VALUE (tail));
3819 /* Cleanups may be run multiple times. For example,
3820 when exiting a binding contour, we expand the
3821 cleanups associated with that contour. When a goto
3822 within that binding contour has a target outside that
3823 contour, it will expand all cleanups from its scope to
3824 the target. Though the cleanups are expanded multiple
3825 times, the control paths are non-overlapping so the
3826 cleanups will not be executed twice. */
3827 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3834 /* Move all cleanups from the current block_stack
3835 to the containing block_stack, where they are assumed to
3836 have been created. If anything can cause a temporary to
3837 be created, but not expanded for more than one level of
3838 block_stacks, then this code will have to change. */
3843 struct nesting *block = block_stack;
3844 struct nesting *outer = block->next;
3846 outer->data.block.cleanups
3847 = chainon (block->data.block.cleanups,
3848 outer->data.block.cleanups);
3849 block->data.block.cleanups = 0;
3853 last_cleanup_this_contour ()
3855 if (block_stack == 0)
3858 return block_stack->data.block.cleanups;
3861 /* Return 1 if there are any pending cleanups at this point.
3862 If THIS_CONTOUR is nonzero, check the current contour as well.
3863 Otherwise, look only at the contours that enclose this one. */
3866 any_pending_cleanups (this_contour)
3869 struct nesting *block;
3871 if (block_stack == 0)
3874 if (this_contour && block_stack->data.block.cleanups != NULL)
3876 if (block_stack->data.block.cleanups == 0
3877 && (block_stack->data.block.outer_cleanups == 0
3879 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3884 for (block = block_stack->next; block; block = block->next)
3885 if (block->data.block.cleanups != 0)
3891 /* Enter a case (Pascal) or switch (C) statement.
3892 Push a block onto case_stack and nesting_stack
3893 to accumulate the case-labels that are seen
3894 and to record the labels generated for the statement.
3896 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3897 Otherwise, this construct is transparent for `exit_something'.
3899 EXPR is the index-expression to be dispatched on.
3900 TYPE is its nominal type. We could simply convert EXPR to this type,
3901 but instead we take short cuts. */
3904 expand_start_case (exit_flag, expr, type, printname)
3910 register struct nesting *thiscase = ALLOC_NESTING ();
3912 /* Make an entry on case_stack for the case we are entering. */
3914 thiscase->next = case_stack;
3915 thiscase->all = nesting_stack;
3916 thiscase->depth = ++nesting_depth;
3917 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3918 thiscase->data.case_stmt.case_list = 0;
3919 thiscase->data.case_stmt.index_expr = expr;
3920 thiscase->data.case_stmt.nominal_type = type;
3921 thiscase->data.case_stmt.default_label = 0;
3922 thiscase->data.case_stmt.num_ranges = 0;
3923 thiscase->data.case_stmt.printname = printname;
3924 thiscase->data.case_stmt.seenlabel = 0;
3925 case_stack = thiscase;
3926 nesting_stack = thiscase;
3928 if (output_bytecode)
3930 bc_expand_start_case (thiscase, expr, type, printname);
3934 do_pending_stack_adjust ();
3936 /* Make sure case_stmt.start points to something that won't
3937 need any transformation before expand_end_case. */
3938 if (GET_CODE (get_last_insn ()) != NOTE)
3939 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3941 thiscase->data.case_stmt.start = get_last_insn ();
3945 /* Enter a case statement. It is assumed that the caller has pushed
3946 the current context onto the case stack. */
3949 bc_expand_start_case (thiscase, expr, type, printname)
3950 struct nesting *thiscase;
3955 bc_expand_expr (expr);
3956 bc_expand_conversion (TREE_TYPE (expr), type);
3958 /* For cases, the skip is a place we jump to that's emitted after
3959 the size of the jump table is known. */
3961 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3962 bc_emit_bytecode (jump);
3963 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3965 #ifdef DEBUG_PRINT_CODE
3966 fputc ('\n', stderr);
3971 /* Start a "dummy case statement" within which case labels are invalid
3972 and are not connected to any larger real case statement.
3973 This can be used if you don't want to let a case statement jump
3974 into the middle of certain kinds of constructs. */
3977 expand_start_case_dummy ()
3979 register struct nesting *thiscase = ALLOC_NESTING ();
3981 /* Make an entry on case_stack for the dummy. */
3983 thiscase->next = case_stack;
3984 thiscase->all = nesting_stack;
3985 thiscase->depth = ++nesting_depth;
3986 thiscase->exit_label = 0;
3987 thiscase->data.case_stmt.case_list = 0;
3988 thiscase->data.case_stmt.start = 0;
3989 thiscase->data.case_stmt.nominal_type = 0;
3990 thiscase->data.case_stmt.default_label = 0;
3991 thiscase->data.case_stmt.num_ranges = 0;
3992 case_stack = thiscase;
3993 nesting_stack = thiscase;
3996 /* End a dummy case statement. */
3999 expand_end_case_dummy ()
4001 POPSTACK (case_stack);
4004 /* Return the data type of the index-expression
4005 of the innermost case statement, or null if none. */
4008 case_index_expr_type ()
4011 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4015 /* Accumulate one case or default label inside a case or switch statement.
4016 VALUE is the value of the case (a null pointer, for a default label).
4017 The function CONVERTER, when applied to arguments T and V,
4018 converts the value V to the type T.
4020 If not currently inside a case or switch statement, return 1 and do
4021 nothing. The caller will print a language-specific error message.
4022 If VALUE is a duplicate or overlaps, return 2 and do nothing
4023 except store the (first) duplicate node in *DUPLICATE.
4024 If VALUE is out of range, return 3 and do nothing.
4025 If we are jumping into the scope of a cleaup or var-sized array, return 5.
4026 Return 0 on success.
4028 Extended to handle range statements. */
4031 pushcase (value, converter, label, duplicate)
4032 register tree value;
4033 tree (*converter) PROTO((tree, tree));
4034 register tree label;
4037 register struct case_node **l;
4038 register struct case_node *n;
4042 if (output_bytecode)
4043 return bc_pushcase (value, label);
4045 /* Fail if not inside a real case statement. */
4046 if (! (case_stack && case_stack->data.case_stmt.start))
4049 if (stack_block_stack
4050 && stack_block_stack->depth > case_stack->depth)
4053 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4054 nominal_type = case_stack->data.case_stmt.nominal_type;
4056 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4057 if (index_type == error_mark_node)
4060 /* Convert VALUE to the type in which the comparisons are nominally done. */
4062 value = (*converter) (nominal_type, value);
4064 /* If this is the first label, warn if any insns have been emitted. */
4065 if (case_stack->data.case_stmt.seenlabel == 0)
4068 for (insn = case_stack->data.case_stmt.start;
4070 insn = NEXT_INSN (insn))
4072 if (GET_CODE (insn) == CODE_LABEL)
4074 if (GET_CODE (insn) != NOTE
4075 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4077 warning ("unreachable code at beginning of %s",
4078 case_stack->data.case_stmt.printname);
4083 case_stack->data.case_stmt.seenlabel = 1;
4085 /* Fail if this value is out of range for the actual type of the index
4086 (which may be narrower than NOMINAL_TYPE). */
4087 if (value != 0 && ! int_fits_type_p (value, index_type))
4090 /* Fail if this is a duplicate or overlaps another entry. */
4093 if (case_stack->data.case_stmt.default_label != 0)
4095 *duplicate = case_stack->data.case_stmt.default_label;
4098 case_stack->data.case_stmt.default_label = label;
4101 return add_case_node (value, value, label, duplicate);
4103 expand_label (label);
4107 /* Like pushcase but this case applies to all values
4108 between VALUE1 and VALUE2 (inclusive).
4109 The return value is the same as that of pushcase
4110 but there is one additional error code:
4111 4 means the specified range was empty. */
4114 pushcase_range (value1, value2, converter, label, duplicate)
4115 register tree value1, value2;
4116 tree (*converter) PROTO((tree, tree));
4117 register tree label;
4120 register struct case_node **l;
4121 register struct case_node *n;
4125 /* Fail if not inside a real case statement. */
4126 if (! (case_stack && case_stack->data.case_stmt.start))
4129 if (stack_block_stack
4130 && stack_block_stack->depth > case_stack->depth)
4133 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4134 nominal_type = case_stack->data.case_stmt.nominal_type;
4136 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4137 if (index_type == error_mark_node)
4140 /* If this is the first label, warn if any insns have been emitted. */
4141 if (case_stack->data.case_stmt.seenlabel == 0)
4144 for (insn = case_stack->data.case_stmt.start;
4146 insn = NEXT_INSN (insn))
4148 if (GET_CODE (insn) == CODE_LABEL)
4150 if (GET_CODE (insn) != NOTE
4151 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4153 warning ("unreachable code at beginning of %s",
4154 case_stack->data.case_stmt.printname);
4159 case_stack->data.case_stmt.seenlabel = 1;
4161 /* Convert VALUEs to type in which the comparisons are nominally done. */
4162 if (value1 == 0) /* Negative infinity. */
4163 value1 = TYPE_MIN_VALUE(index_type);
4164 value1 = (*converter) (nominal_type, value1);
4166 if (value2 == 0) /* Positive infinity. */
4167 value2 = TYPE_MAX_VALUE(index_type);
4168 value2 = (*converter) (nominal_type, value2);
4170 /* Fail if these values are out of range. */
4171 if (! int_fits_type_p (value1, index_type))
4174 if (! int_fits_type_p (value2, index_type))
4177 /* Fail if the range is empty. */
4178 if (tree_int_cst_lt (value2, value1))
4181 return add_case_node (value1, value2, label, duplicate);
4184 /* Do the actual insertion of a case label for pushcase and pushcase_range
4185 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4186 slowdown for large switch statements. */
4189 add_case_node (low, high, label, duplicate)
4194 struct case_node *p, **q, *r;
4196 q = &case_stack->data.case_stmt.case_list;
4203 /* Keep going past elements distinctly greater than HIGH. */
4204 if (tree_int_cst_lt (high, p->low))
4207 /* or distinctly less than LOW. */
4208 else if (tree_int_cst_lt (p->high, low))
4213 /* We have an overlap; this is an error. */
4214 *duplicate = p->code_label;
4219 /* Add this label to the chain, and succeed.
4220 Copy LOW, HIGH so they are on temporary rather than momentary
4221 obstack and will thus survive till the end of the case statement. */
4223 r = (struct case_node *) oballoc (sizeof (struct case_node));
4224 r->low = copy_node (low);
4226 /* If the bounds are equal, turn this into the one-value case. */
4228 if (tree_int_cst_equal (low, high))
4232 r->high = copy_node (high);
4233 case_stack->data.case_stmt.num_ranges++;
4236 r->code_label = label;
4237 expand_label (label);
4247 struct case_node *s;
4253 if (! (b = p->balance))
4254 /* Growth propagation from left side. */
4261 if (p->left = s = r->right)
4278 case_stack->data.case_stmt.case_list = r;
4281 /* r->balance == +1 */
4284 struct case_node *t = r->right;
4286 if (p->left = s = t->right)
4290 if (r->right = s = t->left)
4312 case_stack->data.case_stmt.case_list = t;
4319 /* p->balance == +1; growth of left side balances the node. */
4329 if (! (b = p->balance))
4330 /* Growth propagation from right side. */
4338 if (p->right = s = r->left)
4355 case_stack->data.case_stmt.case_list = r;
4359 /* r->balance == -1 */
4363 struct case_node *t = r->left;
4365 if (p->right = s = t->left)
4370 if (r->left = s = t->right)
4393 case_stack->data.case_stmt.case_list = t;
4399 /* p->balance == -1; growth of right side balances the node. */
4412 /* Accumulate one case or default label; VALUE is the value of the
4413 case, or nil for a default label. If not currently inside a case,
4414 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4415 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4416 Return 0 on success. This function is a leftover from the earlier
4417 bytecode compiler, which was based on gcc 1.37. It should be
4418 merged into pushcase. */
4421 bc_pushcase (value, label)
4425 struct nesting *thiscase = case_stack;
4426 struct case_node *case_label, *new_label;
4431 /* Fail if duplicate, overlap, or out of type range. */
4434 value = convert (thiscase->data.case_stmt.nominal_type, value);
4435 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4438 for (case_label = thiscase->data.case_stmt.case_list;
4439 case_label->left; case_label = case_label->left)
4440 if (! tree_int_cst_lt (case_label->left->high, value))
4443 if (case_label != thiscase->data.case_stmt.case_list
4444 && ! tree_int_cst_lt (case_label->high, value)
4445 || (case_label->left && ! tree_int_cst_lt (value, case_label->left->low)))
4448 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4449 new_label->low = new_label->high = copy_node (value);
4450 new_label->code_label = label;
4451 new_label->left = case_label->left;
4453 case_label->left = new_label;
4454 thiscase->data.case_stmt.num_ranges++;
4458 if (thiscase->data.case_stmt.default_label)
4460 thiscase->data.case_stmt.default_label = label;
4463 expand_label (label);
4467 /* Returns the number of possible values of TYPE.
4468 Returns -1 if the number is unknown or variable.
4469 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4470 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4471 do not increase monotonically (there may be duplicates);
4472 to 1 if the values increase monotonically, but not always by 1;
4473 otherwise sets it to 0. */
4476 all_cases_count (type, spareness)
4480 HOST_WIDE_INT count, count_high = 0;
4483 switch (TREE_CODE (type))
4490 count = 1 << BITS_PER_UNIT;
4494 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4495 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4500 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4501 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4502 but with overflow checking. */
4503 tree mint = TYPE_MIN_VALUE (type);
4504 tree maxt = TYPE_MAX_VALUE (type);
4505 HOST_WIDE_INT lo, hi;
4506 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4508 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4510 add_double (lo, hi, 1, 0, &lo, &hi);
4511 if (hi != 0 || lo < 0)
4518 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4520 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4521 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4522 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4523 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4527 if (*spareness == 1)
4529 tree prev = TREE_VALUE (TYPE_VALUES (type));
4530 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4532 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4537 prev = TREE_VALUE (t);
4546 #define BITARRAY_TEST(ARRAY, INDEX) \
4547 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4548 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4549 #define BITARRAY_SET(ARRAY, INDEX) \
4550 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4551 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4553 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4554 with the case values we have seen, assuming the case expression
4556 SPARSENESS is as determined by all_cases_count.
4558 The time needed is proportional to COUNT, unless
4559 SPARSENESS is 2, in which case quadratic time is needed. */
4562 mark_seen_cases (type, cases_seen, count, sparseness)
4564 unsigned char *cases_seen;
4570 tree next_node_to_try = NULL_TREE;
4571 long next_node_offset = 0;
4573 register struct case_node *n;
4574 tree val = make_node (INTEGER_CST);
4575 TREE_TYPE (val) = type;
4576 for (n = case_stack->data.case_stmt.case_list; n;
4579 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4580 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4581 while ( ! tree_int_cst_lt (n->high, val))
4583 /* Calculate (into xlo) the "offset" of the integer (val).
4584 The element with lowest value has offset 0, the next smallest
4585 element has offset 1, etc. */
4587 HOST_WIDE_INT xlo, xhi;
4589 if (sparseness == 2)
4591 /* This less efficient loop is only needed to handle
4592 duplicate case values (multiple enum constants
4593 with the same value). */
4594 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4595 t = TREE_CHAIN (t), xlo++)
4597 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4598 BITARRAY_SET (cases_seen, xlo);
4603 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4605 /* The TYPE_VALUES will be in increasing order, so
4606 starting searching where we last ended. */
4607 t = next_node_to_try;
4608 xlo = next_node_offset;
4614 t = TYPE_VALUES (type);
4617 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4619 next_node_to_try = TREE_CHAIN (t);
4620 next_node_offset = xlo + 1;
4625 if (t == next_node_to_try)
4631 t = TYPE_MIN_VALUE (type);
4633 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4637 add_double (xlo, xhi,
4638 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4642 if (xhi == 0 && xlo >= 0 && xlo < count)
4643 BITARRAY_SET (cases_seen, xlo);
4645 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4647 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4652 /* Called when the index of a switch statement is an enumerated type
4653 and there is no default label.
4655 Checks that all enumeration literals are covered by the case
4656 expressions of a switch. Also, warn if there are any extra
4657 switch cases that are *not* elements of the enumerated type.
4659 If all enumeration literals were covered by the case expressions,
4660 turn one of the expressions into the default expression since it should
4661 not be possible to fall through such a switch. */
4664 check_for_full_enumeration_handling (type)
4667 register struct case_node *n;
4668 register struct case_node **l;
4669 register tree chain;
4672 /* True iff the selector type is a numbered set mode. */
4675 /* The number of possible selector values. */
4678 /* For each possible selector value. a one iff it has been matched
4679 by a case value alternative. */
4680 unsigned char *cases_seen;
4682 /* The allocated size of cases_seen, in chars. */
4686 if (output_bytecode)
4688 bc_check_for_full_enumeration_handling (type);
4695 size = all_cases_count (type, &sparseness);
4696 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4698 if (size > 0 && size < 600000
4699 /* We deliberately use malloc here - not xmalloc. */
4700 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4703 tree v = TYPE_VALUES (type);
4704 bzero (cases_seen, bytes_needed);
4706 /* The time complexity of this code is normally O(N), where
4707 N being the number of members in the enumerated type.
4708 However, if type is a ENUMERAL_TYPE whose values do not
4709 increase monotonically, quadratic time may be needed. */
4711 mark_seen_cases (type, cases_seen, size, sparseness);
4713 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4715 if (BITARRAY_TEST(cases_seen, i) == 0)
4716 warning ("enumeration value `%s' not handled in switch",
4717 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4723 /* Now we go the other way around; we warn if there are case
4724 expressions that don't correspond to enumerators. This can
4725 occur since C and C++ don't enforce type-checking of
4726 assignments to enumeration variables. */
4729 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4731 for (chain = TYPE_VALUES (type);
4732 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4733 chain = TREE_CHAIN (chain))
4738 if (TYPE_NAME (type) == 0)
4739 warning ("case value `%d' not in enumerated type",
4740 TREE_INT_CST_LOW (n->low));
4742 warning ("case value `%d' not in enumerated type `%s'",
4743 TREE_INT_CST_LOW (n->low),
4744 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4747 : DECL_NAME (TYPE_NAME (type))));
4749 if (!tree_int_cst_equal (n->low, n->high))
4751 for (chain = TYPE_VALUES (type);
4752 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4753 chain = TREE_CHAIN (chain))
4758 if (TYPE_NAME (type) == 0)
4759 warning ("case value `%d' not in enumerated type",
4760 TREE_INT_CST_LOW (n->high));
4762 warning ("case value `%d' not in enumerated type `%s'",
4763 TREE_INT_CST_LOW (n->high),
4764 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4767 : DECL_NAME (TYPE_NAME (type))));
4773 /* ??? This optimization is disabled because it causes valid programs to
4774 fail. ANSI C does not guarantee that an expression with enum type
4775 will have a value that is the same as one of the enumeration literals. */
4777 /* If all values were found as case labels, make one of them the default
4778 label. Thus, this switch will never fall through. We arbitrarily pick
4779 the last one to make the default since this is likely the most
4780 efficient choice. */
4784 for (l = &case_stack->data.case_stmt.case_list;
4789 case_stack->data.case_stmt.default_label = (*l)->code_label;
4796 /* Check that all enumeration literals are covered by the case
4797 expressions of a switch. Also warn if there are any cases
4798 that are not elements of the enumerated type. */
4801 bc_check_for_full_enumeration_handling (type)
4804 struct nesting *thiscase = case_stack;
4805 struct case_node *c;
4808 /* Check for enums not handled. */
4809 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4811 for (c = thiscase->data.case_stmt.case_list->left;
4812 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4815 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4816 warning ("enumerated value `%s' not handled in switch",
4817 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4820 /* Check for cases not in the enumeration. */
4821 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4823 for (e = TYPE_VALUES (type);
4824 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4828 warning ("case value `%d' not in enumerated type `%s'",
4829 TREE_INT_CST_LOW (c->low),
4830 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4832 : DECL_NAME (TYPE_NAME (type))));
4836 /* Terminate a case (Pascal) or switch (C) statement
4837 in which ORIG_INDEX is the expression to be tested.
4838 Generate the code to test it and jump to the right place. */
4841 expand_end_case (orig_index)
4844 tree minval, maxval, range, orig_minval;
4845 rtx default_label = 0;
4846 register struct case_node *n;
4854 register struct nesting *thiscase = case_stack;
4855 tree index_expr, index_type;
4858 if (output_bytecode)
4860 bc_expand_end_case (orig_index);
4864 table_label = gen_label_rtx ();
4865 index_expr = thiscase->data.case_stmt.index_expr;
4866 index_type = TREE_TYPE (index_expr);
4867 unsignedp = TREE_UNSIGNED (index_type);
4869 do_pending_stack_adjust ();
4871 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4872 if (index_type != error_mark_node)
4874 if (thiscase->data.case_stmt.case_list)
4875 thiscase->data.case_stmt.case_list
4876 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
4878 /* If switch expression was an enumerated type, check that all
4879 enumeration literals are covered by the cases.
4880 No sense trying this if there's a default case, however. */
4882 if (!thiscase->data.case_stmt.default_label
4883 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4884 && TREE_CODE (index_expr) != INTEGER_CST)
4885 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4887 /* If this is the first label, warn if any insns have been emitted. */
4888 if (thiscase->data.case_stmt.seenlabel == 0)
4891 for (insn = get_last_insn ();
4892 insn != case_stack->data.case_stmt.start;
4893 insn = PREV_INSN (insn))
4894 if (GET_CODE (insn) != NOTE
4895 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4897 warning ("unreachable code at beginning of %s",
4898 case_stack->data.case_stmt.printname);
4903 /* If we don't have a default-label, create one here,
4904 after the body of the switch. */
4905 if (thiscase->data.case_stmt.default_label == 0)
4907 thiscase->data.case_stmt.default_label
4908 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4909 expand_label (thiscase->data.case_stmt.default_label);
4911 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4913 before_case = get_last_insn ();
4915 /* Simplify the case-list before we count it. */
4916 group_case_nodes (thiscase->data.case_stmt.case_list);
4918 /* Get upper and lower bounds of case values.
4919 Also convert all the case values to the index expr's data type. */
4922 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4924 /* Check low and high label values are integers. */
4925 if (TREE_CODE (n->low) != INTEGER_CST)
4927 if (TREE_CODE (n->high) != INTEGER_CST)
4930 n->low = convert (index_type, n->low);
4931 n->high = convert (index_type, n->high);
4933 /* Count the elements and track the largest and smallest
4934 of them (treating them as signed even if they are not). */
4942 if (INT_CST_LT (n->low, minval))
4944 if (INT_CST_LT (maxval, n->high))
4947 /* A range counts double, since it requires two compares. */
4948 if (! tree_int_cst_equal (n->low, n->high))
4952 orig_minval = minval;
4954 /* Compute span of values. */
4956 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4960 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4962 emit_jump (default_label);
4965 /* If range of values is much bigger than number of values,
4966 make a sequence of conditional branches instead of a dispatch.
4967 If the switch-index is a constant, do it this way
4968 because we can optimize it. */
4970 #ifndef CASE_VALUES_THRESHOLD
4972 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4974 /* If machine does not have a case insn that compares the
4975 bounds, this means extra overhead for dispatch tables
4976 which raises the threshold for using them. */
4977 #define CASE_VALUES_THRESHOLD 5
4978 #endif /* HAVE_casesi */
4979 #endif /* CASE_VALUES_THRESHOLD */
4981 else if (TREE_INT_CST_HIGH (range) != 0
4982 || count < CASE_VALUES_THRESHOLD
4983 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4985 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
4988 || TREE_CODE (index_expr) == INTEGER_CST
4989 /* These will reduce to a constant. */
4990 || (TREE_CODE (index_expr) == CALL_EXPR
4991 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4992 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4993 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4994 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4995 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4997 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4999 /* If the index is a short or char that we do not have
5000 an insn to handle comparisons directly, convert it to
5001 a full integer now, rather than letting each comparison
5002 generate the conversion. */
5004 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5005 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5006 == CODE_FOR_nothing))
5008 enum machine_mode wider_mode;
5009 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5010 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5011 if (cmp_optab->handlers[(int) wider_mode].insn_code
5012 != CODE_FOR_nothing)
5014 index = convert_to_mode (wider_mode, index, unsignedp);
5020 do_pending_stack_adjust ();
5022 index = protect_from_queue (index, 0);
5023 if (GET_CODE (index) == MEM)
5024 index = copy_to_reg (index);
5025 if (GET_CODE (index) == CONST_INT
5026 || TREE_CODE (index_expr) == INTEGER_CST)
5028 /* Make a tree node with the proper constant value
5029 if we don't already have one. */
5030 if (TREE_CODE (index_expr) != INTEGER_CST)
5033 = build_int_2 (INTVAL (index),
5034 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5035 index_expr = convert (index_type, index_expr);
5038 /* For constant index expressions we need only
5039 issue a unconditional branch to the appropriate
5040 target code. The job of removing any unreachable
5041 code is left to the optimisation phase if the
5042 "-O" option is specified. */
5043 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5044 if (! tree_int_cst_lt (index_expr, n->low)
5045 && ! tree_int_cst_lt (n->high, index_expr))
5049 emit_jump (label_rtx (n->code_label));
5051 emit_jump (default_label);
5055 /* If the index expression is not constant we generate
5056 a binary decision tree to select the appropriate
5057 target code. This is done as follows:
5059 The list of cases is rearranged into a binary tree,
5060 nearly optimal assuming equal probability for each case.
5062 The tree is transformed into RTL, eliminating
5063 redundant test conditions at the same time.
5065 If program flow could reach the end of the
5066 decision tree an unconditional jump to the
5067 default code is emitted. */
5070 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5071 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5072 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5074 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5075 default_label, index_type);
5076 emit_jump_if_reachable (default_label);
5085 enum machine_mode index_mode = SImode;
5086 int index_bits = GET_MODE_BITSIZE (index_mode);
5088 enum machine_mode op_mode;
5090 /* Convert the index to SImode. */
5091 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5092 > GET_MODE_BITSIZE (index_mode))
5094 enum machine_mode omode = TYPE_MODE (index_type);
5095 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5097 /* We must handle the endpoints in the original mode. */
5098 index_expr = build (MINUS_EXPR, index_type,
5099 index_expr, minval);
5100 minval = integer_zero_node;
5101 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5102 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
5103 emit_jump_insn (gen_bltu (default_label));
5104 /* Now we can safely truncate. */
5105 index = convert_to_mode (index_mode, index, 0);
5109 if (TYPE_MODE (index_type) != index_mode)
5111 index_expr = convert (type_for_size (index_bits, 0),
5113 index_type = TREE_TYPE (index_expr);
5116 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5119 index = protect_from_queue (index, 0);
5120 do_pending_stack_adjust ();
5122 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
5123 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
5125 index = copy_to_mode_reg (op_mode, index);
5127 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5129 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
5130 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
5132 op1 = copy_to_mode_reg (op_mode, op1);
5134 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5136 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
5137 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
5139 op2 = copy_to_mode_reg (op_mode, op2);
5141 emit_jump_insn (gen_casesi (index, op1, op2,
5142 table_label, default_label));
5146 #ifdef HAVE_tablejump
5147 if (! win && HAVE_tablejump)
5149 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5150 fold (build (MINUS_EXPR, index_type,
5151 index_expr, minval)));
5152 index_type = TREE_TYPE (index_expr);
5153 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5155 index = protect_from_queue (index, 0);
5156 do_pending_stack_adjust ();
5158 do_tablejump (index, TYPE_MODE (index_type),
5159 expand_expr (range, NULL_RTX, VOIDmode, 0),
5160 table_label, default_label);
5167 /* Get table of labels to jump to, in order of case index. */
5169 ncases = TREE_INT_CST_LOW (range) + 1;
5170 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5171 bzero ((char *) labelvec, ncases * sizeof (rtx));
5173 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5175 register HOST_WIDE_INT i
5176 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5181 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
5182 if (i + TREE_INT_CST_LOW (orig_minval)
5183 == TREE_INT_CST_LOW (n->high))
5189 /* Fill in the gaps with the default. */
5190 for (i = 0; i < ncases; i++)
5191 if (labelvec[i] == 0)
5192 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
5194 /* Output the table */
5195 emit_label (table_label);
5197 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
5198 were an expression, instead of an #ifdef/#ifndef. */
5200 #ifdef CASE_VECTOR_PC_RELATIVE
5204 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
5205 gen_rtx (LABEL_REF, Pmode, table_label),
5206 gen_rtvec_v (ncases, labelvec)));
5208 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
5209 gen_rtvec_v (ncases, labelvec)));
5211 /* If the case insn drops through the table,
5212 after the table we must jump to the default-label.
5213 Otherwise record no drop-through after the table. */
5214 #ifdef CASE_DROPS_THROUGH
5215 emit_jump (default_label);
5221 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5222 reorder_insns (before_case, get_last_insn (),
5223 thiscase->data.case_stmt.start);
5226 if (thiscase->exit_label)
5227 emit_label (thiscase->exit_label);
5229 POPSTACK (case_stack);
5234 /* Convert the tree NODE into a list linked by the right field, with the left
5235 field zeroed. RIGHT is used for recursion; it is a list to be placed
5236 rightmost in the resulting list. */
5238 static struct case_node *
5239 case_tree2list (node, right)
5240 struct case_node *node, *right;
5242 struct case_node *left;
5245 right = case_tree2list (node->right, right);
5247 node->right = right;
5248 if (left = node->left)
5251 return case_tree2list (left, node);
5257 /* Terminate a case statement. EXPR is the original index
5261 bc_expand_end_case (expr)
5264 struct nesting *thiscase = case_stack;
5265 enum bytecode_opcode opcode;
5266 struct bc_label *jump_label;
5267 struct case_node *c;
5269 bc_emit_bytecode (jump);
5270 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5272 #ifdef DEBUG_PRINT_CODE
5273 fputc ('\n', stderr);
5276 /* Now that the size of the jump table is known, emit the actual
5277 indexed jump instruction. */
5278 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5280 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5281 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5282 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5284 bc_emit_bytecode (opcode);
5286 /* Now emit the case instructions literal arguments, in order.
5287 In addition to the value on the stack, it uses:
5288 1. The address of the jump table.
5289 2. The size of the jump table.
5290 3. The default label. */
5292 jump_label = bc_get_bytecode_label ();
5293 bc_emit_bytecode_labelref (jump_label);
5294 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5295 sizeof thiscase->data.case_stmt.num_ranges);
5297 if (thiscase->data.case_stmt.default_label)
5298 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5300 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5302 /* Output the jump table. */
5304 bc_align_bytecode (3 /* PTR_ALIGN */);
5305 bc_emit_bytecode_labeldef (jump_label);
5307 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5308 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5310 opcode = TREE_INT_CST_LOW (c->low);
5311 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5313 opcode = TREE_INT_CST_LOW (c->high);
5314 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5316 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5319 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5320 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5322 bc_emit_bytecode_DI_const (c->low);
5323 bc_emit_bytecode_DI_const (c->high);
5325 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5332 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5334 /* Possibly issue enumeration warnings. */
5336 if (!thiscase->data.case_stmt.default_label
5337 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5338 && TREE_CODE (expr) != INTEGER_CST
5340 check_for_full_enumeration_handling (TREE_TYPE (expr));
5343 #ifdef DEBUG_PRINT_CODE
5344 fputc ('\n', stderr);
5347 POPSTACK (case_stack);
5351 /* Return unique bytecode ID. */
5356 static int bc_uid = 0;
5361 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5364 do_jump_if_equal (op1, op2, label, unsignedp)
5365 rtx op1, op2, label;
5368 if (GET_CODE (op1) == CONST_INT
5369 && GET_CODE (op2) == CONST_INT)
5371 if (INTVAL (op1) == INTVAL (op2))
5376 enum machine_mode mode = GET_MODE (op1);
5377 if (mode == VOIDmode)
5378 mode = GET_MODE (op2);
5379 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5380 emit_jump_insn (gen_beq (label));
5384 /* Not all case values are encountered equally. This function
5385 uses a heuristic to weight case labels, in cases where that
5386 looks like a reasonable thing to do.
5388 Right now, all we try to guess is text, and we establish the
5391 chars above space: 16
5400 If we find any cases in the switch that are not either -1 or in the range
5401 of valid ASCII characters, or are control characters other than those
5402 commonly used with "\", don't treat this switch scanning text.
5404 Return 1 if these nodes are suitable for cost estimation, otherwise
5408 estimate_case_costs (node)
5411 tree min_ascii = build_int_2 (-1, -1);
5412 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5416 /* If we haven't already made the cost table, make it now. Note that the
5417 lower bound of the table is -1, not zero. */
5419 if (cost_table == NULL)
5421 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5422 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5424 for (i = 0; i < 128; i++)
5428 else if (ispunct (i))
5430 else if (iscntrl (i))
5434 cost_table[' '] = 8;
5435 cost_table['\t'] = 4;
5436 cost_table['\0'] = 4;
5437 cost_table['\n'] = 2;
5438 cost_table['\f'] = 1;
5439 cost_table['\v'] = 1;
5440 cost_table['\b'] = 1;
5443 /* See if all the case expressions look like text. It is text if the
5444 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5445 as signed arithmetic since we don't want to ever access cost_table with a
5446 value less than -1. Also check that none of the constants in a range
5447 are strange control characters. */
5449 for (n = node; n; n = n->right)
5451 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5454 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5455 if (cost_table[i] < 0)
5459 /* All interesting values are within the range of interesting
5460 ASCII characters. */
5464 /* Scan an ordered list of case nodes
5465 combining those with consecutive values or ranges.
5467 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5470 group_case_nodes (head)
5473 case_node_ptr node = head;
5477 rtx lb = next_real_insn (label_rtx (node->code_label));
5478 case_node_ptr np = node;
5480 /* Try to group the successors of NODE with NODE. */
5481 while (((np = np->right) != 0)
5482 /* Do they jump to the same place? */
5483 && next_real_insn (label_rtx (np->code_label)) == lb
5484 /* Are their ranges consecutive? */
5485 && tree_int_cst_equal (np->low,
5486 fold (build (PLUS_EXPR,
5487 TREE_TYPE (node->high),
5490 /* An overflow is not consecutive. */
5491 && tree_int_cst_lt (node->high,
5492 fold (build (PLUS_EXPR,
5493 TREE_TYPE (node->high),
5495 integer_one_node))))
5497 node->high = np->high;
5499 /* NP is the first node after NODE which can't be grouped with it.
5500 Delete the nodes in between, and move on to that node. */
5506 /* Take an ordered list of case nodes
5507 and transform them into a near optimal binary tree,
5508 on the assumption that any target code selection value is as
5509 likely as any other.
5511 The transformation is performed by splitting the ordered
5512 list into two equal sections plus a pivot. The parts are
5513 then attached to the pivot as left and right branches. Each
5514 branch is is then transformed recursively. */
5517 balance_case_nodes (head, parent)
5518 case_node_ptr *head;
5519 case_node_ptr parent;
5521 register case_node_ptr np;
5529 register case_node_ptr *npp;
5532 /* Count the number of entries on branch. Also count the ranges. */
5536 if (!tree_int_cst_equal (np->low, np->high))
5540 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5544 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5552 /* Split this list if it is long enough for that to help. */
5557 /* Find the place in the list that bisects the list's total cost,
5558 Here I gets half the total cost. */
5563 /* Skip nodes while their cost does not reach that amount. */
5564 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5565 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5566 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5569 npp = &(*npp)->right;
5574 /* Leave this branch lopsided, but optimize left-hand
5575 side and fill in `parent' fields for right-hand side. */
5577 np->parent = parent;
5578 balance_case_nodes (&np->left, np);
5579 for (; np->right; np = np->right)
5580 np->right->parent = np;
5584 /* If there are just three nodes, split at the middle one. */
5586 npp = &(*npp)->right;
5589 /* Find the place in the list that bisects the list's total cost,
5590 where ranges count as 2.
5591 Here I gets half the total cost. */
5592 i = (i + ranges + 1) / 2;
5595 /* Skip nodes while their cost does not reach that amount. */
5596 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5601 npp = &(*npp)->right;
5606 np->parent = parent;
5609 /* Optimize each of the two split parts. */
5610 balance_case_nodes (&np->left, np);
5611 balance_case_nodes (&np->right, np);
5615 /* Else leave this branch as one level,
5616 but fill in `parent' fields. */
5618 np->parent = parent;
5619 for (; np->right; np = np->right)
5620 np->right->parent = np;
5625 /* Search the parent sections of the case node tree
5626 to see if a test for the lower bound of NODE would be redundant.
5627 INDEX_TYPE is the type of the index expression.
5629 The instructions to generate the case decision tree are
5630 output in the same order as nodes are processed so it is
5631 known that if a parent node checks the range of the current
5632 node minus one that the current node is bounded at its lower
5633 span. Thus the test would be redundant. */
5636 node_has_low_bound (node, index_type)
5641 case_node_ptr pnode;
5643 /* If the lower bound of this node is the lowest value in the index type,
5644 we need not test it. */
5646 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5649 /* If this node has a left branch, the value at the left must be less
5650 than that at this node, so it cannot be bounded at the bottom and
5651 we need not bother testing any further. */
5656 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5657 node->low, integer_one_node));
5659 /* If the subtraction above overflowed, we can't verify anything.
5660 Otherwise, look for a parent that tests our value - 1. */
5662 if (! tree_int_cst_lt (low_minus_one, node->low))
5665 for (pnode = node->parent; pnode; pnode = pnode->parent)
5666 if (tree_int_cst_equal (low_minus_one, pnode->high))
5672 /* Search the parent sections of the case node tree
5673 to see if a test for the upper bound of NODE would be redundant.
5674 INDEX_TYPE is the type of the index expression.
5676 The instructions to generate the case decision tree are
5677 output in the same order as nodes are processed so it is
5678 known that if a parent node checks the range of the current
5679 node plus one that the current node is bounded at its upper
5680 span. Thus the test would be redundant. */
5683 node_has_high_bound (node, index_type)
5688 case_node_ptr pnode;
5690 /* If the upper bound of this node is the highest value in the type
5691 of the index expression, we need not test against it. */
5693 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5696 /* If this node has a right branch, the value at the right must be greater
5697 than that at this node, so it cannot be bounded at the top and
5698 we need not bother testing any further. */
5703 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5704 node->high, integer_one_node));
5706 /* If the addition above overflowed, we can't verify anything.
5707 Otherwise, look for a parent that tests our value + 1. */
5709 if (! tree_int_cst_lt (node->high, high_plus_one))
5712 for (pnode = node->parent; pnode; pnode = pnode->parent)
5713 if (tree_int_cst_equal (high_plus_one, pnode->low))
5719 /* Search the parent sections of the
5720 case node tree to see if both tests for the upper and lower
5721 bounds of NODE would be redundant. */
5724 node_is_bounded (node, index_type)
5728 return (node_has_low_bound (node, index_type)
5729 && node_has_high_bound (node, index_type));
5732 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5735 emit_jump_if_reachable (label)
5738 if (GET_CODE (get_last_insn ()) != BARRIER)
5742 /* Emit step-by-step code to select a case for the value of INDEX.
5743 The thus generated decision tree follows the form of the
5744 case-node binary tree NODE, whose nodes represent test conditions.
5745 INDEX_TYPE is the type of the index of the switch.
5747 Care is taken to prune redundant tests from the decision tree
5748 by detecting any boundary conditions already checked by
5749 emitted rtx. (See node_has_high_bound, node_has_low_bound
5750 and node_is_bounded, above.)
5752 Where the test conditions can be shown to be redundant we emit
5753 an unconditional jump to the target code. As a further
5754 optimization, the subordinates of a tree node are examined to
5755 check for bounded nodes. In this case conditional and/or
5756 unconditional jumps as a result of the boundary check for the
5757 current node are arranged to target the subordinates associated
5758 code for out of bound conditions on the current node node.
5760 We can assume that when control reaches the code generated here,
5761 the index value has already been compared with the parents
5762 of this node, and determined to be on the same side of each parent
5763 as this node is. Thus, if this node tests for the value 51,
5764 and a parent tested for 52, we don't need to consider
5765 the possibility of a value greater than 51. If another parent
5766 tests for the value 50, then this node need not test anything. */
5769 emit_case_nodes (index, node, default_label, index_type)
5775 /* If INDEX has an unsigned type, we must make unsigned branches. */
5776 int unsignedp = TREE_UNSIGNED (index_type);
5777 typedef rtx rtx_function ();
5778 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5779 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5780 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5781 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5782 enum machine_mode mode = GET_MODE (index);
5784 /* See if our parents have already tested everything for us.
5785 If they have, emit an unconditional jump for this node. */
5786 if (node_is_bounded (node, index_type))
5787 emit_jump (label_rtx (node->code_label));
5789 else if (tree_int_cst_equal (node->low, node->high))
5791 /* Node is single valued. First see if the index expression matches
5792 this node and then check our children, if any. */
5794 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5795 label_rtx (node->code_label), unsignedp);
5797 if (node->right != 0 && node->left != 0)
5799 /* This node has children on both sides.
5800 Dispatch to one side or the other
5801 by comparing the index value with this node's value.
5802 If one subtree is bounded, check that one first,
5803 so we can avoid real branches in the tree. */
5805 if (node_is_bounded (node->right, index_type))
5807 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5809 GT, NULL_RTX, mode, unsignedp, 0);
5811 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5812 emit_case_nodes (index, node->left, default_label, index_type);
5815 else if (node_is_bounded (node->left, index_type))
5817 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5819 LT, NULL_RTX, mode, unsignedp, 0);
5820 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5821 emit_case_nodes (index, node->right, default_label, index_type);
5826 /* Neither node is bounded. First distinguish the two sides;
5827 then emit the code for one side at a time. */
5830 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5832 /* See if the value is on the right. */
5833 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5835 GT, NULL_RTX, mode, unsignedp, 0);
5836 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5838 /* Value must be on the left.
5839 Handle the left-hand subtree. */
5840 emit_case_nodes (index, node->left, default_label, index_type);
5841 /* If left-hand subtree does nothing,
5843 emit_jump_if_reachable (default_label);
5845 /* Code branches here for the right-hand subtree. */
5846 expand_label (test_label);
5847 emit_case_nodes (index, node->right, default_label, index_type);
5851 else if (node->right != 0 && node->left == 0)
5853 /* Here we have a right child but no left so we issue conditional
5854 branch to default and process the right child.
5856 Omit the conditional branch to default if we it avoid only one
5857 right child; it costs too much space to save so little time. */
5859 if (node->right->right || node->right->left
5860 || !tree_int_cst_equal (node->right->low, node->right->high))
5862 if (!node_has_low_bound (node, index_type))
5864 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5866 LT, NULL_RTX, mode, unsignedp, 0);
5867 emit_jump_insn ((*gen_blt_pat) (default_label));
5870 emit_case_nodes (index, node->right, default_label, index_type);
5873 /* We cannot process node->right normally
5874 since we haven't ruled out the numbers less than
5875 this node's value. So handle node->right explicitly. */
5876 do_jump_if_equal (index,
5877 expand_expr (node->right->low, NULL_RTX,
5879 label_rtx (node->right->code_label), unsignedp);
5882 else if (node->right == 0 && node->left != 0)
5884 /* Just one subtree, on the left. */
5886 #if 0 /* The following code and comment were formerly part
5887 of the condition here, but they didn't work
5888 and I don't understand what the idea was. -- rms. */
5889 /* If our "most probable entry" is less probable
5890 than the default label, emit a jump to
5891 the default label using condition codes
5892 already lying around. With no right branch,
5893 a branch-greater-than will get us to the default
5896 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5899 if (node->left->left || node->left->right
5900 || !tree_int_cst_equal (node->left->low, node->left->high))
5902 if (!node_has_high_bound (node, index_type))
5904 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5906 GT, NULL_RTX, mode, unsignedp, 0);
5907 emit_jump_insn ((*gen_bgt_pat) (default_label));
5910 emit_case_nodes (index, node->left, default_label, index_type);
5913 /* We cannot process node->left normally
5914 since we haven't ruled out the numbers less than
5915 this node's value. So handle node->left explicitly. */
5916 do_jump_if_equal (index,
5917 expand_expr (node->left->low, NULL_RTX,
5919 label_rtx (node->left->code_label), unsignedp);
5924 /* Node is a range. These cases are very similar to those for a single
5925 value, except that we do not start by testing whether this node
5926 is the one to branch to. */
5928 if (node->right != 0 && node->left != 0)
5930 /* Node has subtrees on both sides.
5931 If the right-hand subtree is bounded,
5932 test for it first, since we can go straight there.
5933 Otherwise, we need to make a branch in the control structure,
5934 then handle the two subtrees. */
5935 tree test_label = 0;
5937 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5939 GT, NULL_RTX, mode, unsignedp, 0);
5941 if (node_is_bounded (node->right, index_type))
5942 /* Right hand node is fully bounded so we can eliminate any
5943 testing and branch directly to the target code. */
5944 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5947 /* Right hand node requires testing.
5948 Branch to a label where we will handle it later. */
5950 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5951 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5954 /* Value belongs to this node or to the left-hand subtree. */
5956 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5957 GE, NULL_RTX, mode, unsignedp, 0);
5958 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5960 /* Handle the left-hand subtree. */
5961 emit_case_nodes (index, node->left, default_label, index_type);
5963 /* If right node had to be handled later, do that now. */
5967 /* If the left-hand subtree fell through,
5968 don't let it fall into the right-hand subtree. */
5969 emit_jump_if_reachable (default_label);
5971 expand_label (test_label);
5972 emit_case_nodes (index, node->right, default_label, index_type);
5976 else if (node->right != 0 && node->left == 0)
5978 /* Deal with values to the left of this node,
5979 if they are possible. */
5980 if (!node_has_low_bound (node, index_type))
5982 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5984 LT, NULL_RTX, mode, unsignedp, 0);
5985 emit_jump_insn ((*gen_blt_pat) (default_label));
5988 /* Value belongs to this node or to the right-hand subtree. */
5990 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5992 LE, NULL_RTX, mode, unsignedp, 0);
5993 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5995 emit_case_nodes (index, node->right, default_label, index_type);
5998 else if (node->right == 0 && node->left != 0)
6000 /* Deal with values to the right of this node,
6001 if they are possible. */
6002 if (!node_has_high_bound (node, index_type))
6004 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
6006 GT, NULL_RTX, mode, unsignedp, 0);
6007 emit_jump_insn ((*gen_bgt_pat) (default_label));
6010 /* Value belongs to this node or to the left-hand subtree. */
6012 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6013 GE, NULL_RTX, mode, unsignedp, 0);
6014 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
6016 emit_case_nodes (index, node->left, default_label, index_type);
6021 /* Node has no children so we check low and high bounds to remove
6022 redundant tests. Only one of the bounds can exist,
6023 since otherwise this node is bounded--a case tested already. */
6025 if (!node_has_high_bound (node, index_type))
6027 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
6029 GT, NULL_RTX, mode, unsignedp, 0);
6030 emit_jump_insn ((*gen_bgt_pat) (default_label));
6033 if (!node_has_low_bound (node, index_type))
6035 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
6037 LT, NULL_RTX, mode, unsignedp, 0);
6038 emit_jump_insn ((*gen_blt_pat) (default_label));
6041 emit_jump (label_rtx (node->code_label));
6046 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6047 so that the debugging info will be correct for the unrolled loop. */
6049 /* Indexed by block number, contains a pointer to the N'th block node. */
6051 static tree *block_vector;
6054 find_loop_tree_blocks ()
6056 tree block = DECL_INITIAL (current_function_decl);
6058 block_vector = identify_blocks (block, get_insns ());
6062 unroll_block_trees ()
6064 tree block = DECL_INITIAL (current_function_decl);
6066 reorder_blocks (block_vector, block, get_insns ());