1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92, 93, 94, 1995 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 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 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
110 So we can mark them all live at the end of the function, if nonopt. */
111 extern rtx save_expr_regs;
113 /* Offset to end of allocated area of stack frame.
114 If stack grows down, this is the address of the last stack slot allocated.
115 If stack grows up, this is the address for the next slot. */
116 extern int frame_offset;
118 /* Label to jump back to for tail recursion, or 0 if we have
119 not yet needed one for this function. */
120 extern rtx tail_recursion_label;
122 /* Place after which to insert the tail_recursion_label if we need one. */
123 extern rtx tail_recursion_reentry;
125 /* Location at which to save the argument pointer if it will need to be
126 referenced. There are two cases where this is done: if nonlocal gotos
127 exist, or if vars whose is an offset from the argument pointer will be
128 needed by inner routines. */
130 extern rtx arg_pointer_save_area;
132 /* Chain of all RTL_EXPRs that have insns in them. */
133 extern tree rtl_expr_chain;
135 #if 0 /* Turned off because 0 seems to work just as well. */
136 /* Cleanup lists are required for binding levels regardless of whether
137 that binding level has cleanups or not. This node serves as the
138 cleanup list whenever an empty list is required. */
139 static tree empty_cleanup_list;
142 extern void (*interim_eh_hook) PROTO((tree));
144 /* Functions and data structures for expanding case statements. */
146 /* Case label structure, used to hold info on labels within case
147 statements. We handle "range" labels; for a single-value label
148 as in C, the high and low limits are the same.
150 A chain of case nodes is initially maintained via the RIGHT fields
151 in the nodes. Nodes with higher case values are later in the list.
153 Switch statements can be output in one of two forms. A branch table
154 is used if there are more than a few labels and the labels are dense
155 within the range between the smallest and largest case value. If a
156 branch table is used, no further manipulations are done with the case
159 The alternative to the use of a branch table is to generate a series
160 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
161 and PARENT fields to hold a binary tree. Initially the tree is
162 totally unbalanced, with everything on the right. We balance the tree
163 with nodes on the left having lower case values than the parent
164 and nodes on the right having higher values. We then output the tree
169 struct case_node *left; /* Left son in binary tree */
170 struct case_node *right; /* Right son in binary tree; also node chain */
171 struct case_node *parent; /* Parent of node in binary tree */
172 tree low; /* Lowest index value for this label */
173 tree high; /* Highest index value for this label */
174 tree code_label; /* Label to jump to when node matches */
177 typedef struct case_node case_node;
178 typedef struct case_node *case_node_ptr;
180 /* These are used by estimate_case_costs and balance_case_nodes. */
182 /* This must be a signed type, and non-ANSI compilers lack signed char. */
183 static short *cost_table;
184 static int use_cost_table;
186 /* Stack of control and binding constructs we are currently inside.
188 These constructs begin when you call `expand_start_WHATEVER'
189 and end when you call `expand_end_WHATEVER'. This stack records
190 info about how the construct began that tells the end-function
191 what to do. It also may provide information about the construct
192 to alter the behavior of other constructs within the body.
193 For example, they may affect the behavior of C `break' and `continue'.
195 Each construct gets one `struct nesting' object.
196 All of these objects are chained through the `all' field.
197 `nesting_stack' points to the first object (innermost construct).
198 The position of an entry on `nesting_stack' is in its `depth' field.
200 Each type of construct has its own individual stack.
201 For example, loops have `loop_stack'. Each object points to the
202 next object of the same type through the `next' field.
204 Some constructs are visible to `break' exit-statements and others
205 are not. Which constructs are visible depends on the language.
206 Therefore, the data structure allows each construct to be visible
207 or not, according to the args given when the construct is started.
208 The construct is visible if the `exit_label' field is non-null.
209 In that case, the value should be a CODE_LABEL rtx. */
214 struct nesting *next;
219 /* For conds (if-then and if-then-else statements). */
222 /* Label for the end of the if construct.
223 There is none if EXITFLAG was not set
224 and no `else' has been seen yet. */
226 /* Label for the end of this alternative.
227 This may be the end of the if or the next else/elseif. */
233 /* Label at the top of the loop; place to loop back to. */
235 /* Label at the end of the whole construct. */
237 /* Label before a jump that branches to the end of the whole
238 construct. This is where destructors go if any. */
240 /* Label for `continue' statement to jump to;
241 this is in front of the stepper of the loop. */
244 /* For variable binding contours. */
247 /* Sequence number of this binding contour within the function,
248 in order of entry. */
249 int block_start_count;
250 /* Nonzero => value to restore stack to on exit. Complemented by
251 bc_stack_level (see below) when generating bytecodes. */
253 /* The NOTE that starts this contour.
254 Used by expand_goto to check whether the destination
255 is within each contour or not. */
257 /* Innermost containing binding contour that has a stack level. */
258 struct nesting *innermost_stack_block;
259 /* List of cleanups to be run on exit from this contour.
260 This is a list of expressions to be evaluated.
261 The TREE_PURPOSE of each link is the ..._DECL node
262 which the cleanup pertains to. */
264 /* List of cleanup-lists of blocks containing this block,
265 as they were at the locus where this block appears.
266 There is an element for each containing block,
267 ordered innermost containing block first.
268 The tail of this list can be 0 (was empty_cleanup_list),
269 if all remaining elements would be empty lists.
270 The element's TREE_VALUE is the cleanup-list of that block,
271 which may be null. */
273 /* Chain of labels defined inside this binding contour.
274 For contours that have stack levels or cleanups. */
275 struct label_chain *label_chain;
276 /* Number of function calls seen, as of start of this block. */
277 int function_call_count;
278 /* Bytecode specific: stack level to restore stack to on exit. */
281 /* For switch (C) or case (Pascal) statements,
282 and also for dummies (see `expand_start_case_dummy'). */
285 /* The insn after which the case dispatch should finally
286 be emitted. Zero for a dummy. */
288 /* For bytecodes, the case table is in-lined right in the code.
289 A label is needed for skipping over this block. It is only
290 used when generating bytecodes. */
292 /* A list of case labels, kept in ascending order by value
293 as the list is built.
294 During expand_end_case, this list may be rearranged into a
295 nearly balanced binary tree. */
296 struct case_node *case_list;
297 /* Label to jump to if no case matches. */
299 /* The expression to be dispatched on. */
301 /* Type that INDEX_EXPR should be converted to. */
303 /* Number of range exprs in case statement. */
305 /* Name of this kind of statement, for warnings. */
307 /* Nonzero if a case label has been seen in this case stmt. */
313 /* Chain of all pending binding contours. */
314 struct nesting *block_stack;
316 /* If any new stacks are added here, add them to POPSTACKS too. */
318 /* Chain of all pending binding contours that restore stack levels
320 struct nesting *stack_block_stack;
322 /* Chain of all pending conditional statements. */
323 struct nesting *cond_stack;
325 /* Chain of all pending loops. */
326 struct nesting *loop_stack;
328 /* Chain of all pending case or switch statements. */
329 struct nesting *case_stack;
331 /* Separate chain including all of the above,
332 chained through the `all' field. */
333 struct nesting *nesting_stack;
335 /* Number of entries on nesting_stack now. */
338 /* Allocate and return a new `struct nesting'. */
340 #define ALLOC_NESTING() \
341 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
343 /* Pop the nesting stack element by element until we pop off
344 the element which is at the top of STACK.
345 Update all the other stacks, popping off elements from them
346 as we pop them from nesting_stack. */
348 #define POPSTACK(STACK) \
349 do { struct nesting *target = STACK; \
350 struct nesting *this; \
351 do { this = nesting_stack; \
352 if (loop_stack == this) \
353 loop_stack = loop_stack->next; \
354 if (cond_stack == this) \
355 cond_stack = cond_stack->next; \
356 if (block_stack == this) \
357 block_stack = block_stack->next; \
358 if (stack_block_stack == this) \
359 stack_block_stack = stack_block_stack->next; \
360 if (case_stack == this) \
361 case_stack = case_stack->next; \
362 nesting_depth = nesting_stack->depth - 1; \
363 nesting_stack = this->all; \
364 obstack_free (&stmt_obstack, this); } \
365 while (this != target); } while (0)
367 /* In some cases it is impossible to generate code for a forward goto
368 until the label definition is seen. This happens when it may be necessary
369 for the goto to reset the stack pointer: we don't yet know how to do that.
370 So expand_goto puts an entry on this fixup list.
371 Each time a binding contour that resets the stack is exited,
373 If the target label has now been defined, we can insert the proper code. */
377 /* Points to following fixup. */
378 struct goto_fixup *next;
379 /* Points to the insn before the jump insn.
380 If more code must be inserted, it goes after this insn. */
382 /* The LABEL_DECL that this jump is jumping to, or 0
383 for break, continue or return. */
385 /* The BLOCK for the place where this goto was found. */
387 /* The CODE_LABEL rtx that this is jumping to. */
389 /* Number of binding contours started in current function
390 before the label reference. */
391 int block_start_count;
392 /* The outermost stack level that should be restored for this jump.
393 Each time a binding contour that resets the stack is exited,
394 if the target label is *not* yet defined, this slot is updated. */
396 /* List of lists of cleanup expressions to be run by this goto.
397 There is one element for each block that this goto is within.
398 The tail of this list can be 0 (was empty_cleanup_list),
399 if all remaining elements would be empty.
400 The TREE_VALUE contains the cleanup list of that block as of the
401 time this goto was seen.
402 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
403 tree cleanup_list_list;
405 /* Bytecode specific members follow */
407 /* The label that this jump is jumping to, or 0 for break, continue
409 struct bc_label *bc_target;
411 /* The label we use for the fixup patch */
412 struct bc_label *label;
414 /* True (non-0) if fixup has been handled */
417 /* Like stack_level above, except refers to the interpreter stack */
421 static struct goto_fixup *goto_fixup_chain;
423 /* Within any binding contour that must restore a stack level,
424 all labels are recorded with a chain of these structures. */
428 /* Points to following fixup. */
429 struct label_chain *next;
432 static void expand_goto_internal PROTO((tree, rtx, rtx));
433 static void bc_expand_goto_internal PROTO((enum bytecode_opcode,
434 struct bc_label *, tree));
435 static int expand_fixup PROTO((tree, rtx, rtx));
436 static void bc_expand_fixup PROTO((enum bytecode_opcode,
437 struct bc_label *, int));
438 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
440 static void bc_fixup_gotos PROTO((struct nesting *, int, tree,
442 static void bc_expand_start_cond PROTO((tree, int));
443 static void bc_expand_end_cond PROTO((void));
444 static void bc_expand_start_else PROTO((void));
445 static void bc_expand_end_loop PROTO((void));
446 static void bc_expand_end_bindings PROTO((tree, int, int));
447 static void bc_expand_decl PROTO((tree, tree));
448 static void bc_expand_variable_local_init PROTO((tree));
449 static void bc_expand_decl_init PROTO((tree));
450 static void expand_null_return_1 PROTO((rtx, int));
451 static void expand_value_return PROTO((rtx));
452 static int tail_recursion_args PROTO((tree, tree));
453 static void expand_cleanups PROTO((tree, tree, int, int));
454 static void bc_expand_start_case PROTO((struct nesting *, tree,
456 static int bc_pushcase PROTO((tree, tree));
457 static void bc_check_for_full_enumeration_handling PROTO((tree));
458 static void bc_expand_end_case PROTO((tree));
459 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
460 static int estimate_case_costs PROTO((case_node_ptr));
461 static void group_case_nodes PROTO((case_node_ptr));
462 static void balance_case_nodes PROTO((case_node_ptr *,
464 static int node_has_low_bound PROTO((case_node_ptr, tree));
465 static int node_has_high_bound PROTO((case_node_ptr, tree));
466 static int node_is_bounded PROTO((case_node_ptr, tree));
467 static void emit_jump_if_reachable PROTO((rtx));
468 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
470 int bc_expand_exit_loop_if_false ();
471 void bc_expand_start_cond ();
472 void bc_expand_end_cond ();
473 void bc_expand_start_else ();
474 void bc_expand_end_bindings ();
475 void bc_expand_start_case ();
476 void bc_check_for_full_enumeration_handling ();
477 void bc_expand_end_case ();
478 void bc_expand_decl ();
480 extern rtx bc_allocate_local ();
481 extern rtx bc_allocate_variable_array ();
486 gcc_obstack_init (&stmt_obstack);
488 empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE);
493 init_stmt_for_function ()
495 /* We are not currently within any block, conditional, loop or case. */
497 stack_block_stack = 0;
504 block_start_count = 0;
506 /* No gotos have been expanded yet. */
507 goto_fixup_chain = 0;
509 /* We are not processing a ({...}) grouping. */
510 expr_stmts_for_value = 0;
518 p->block_stack = block_stack;
519 p->stack_block_stack = stack_block_stack;
520 p->cond_stack = cond_stack;
521 p->loop_stack = loop_stack;
522 p->case_stack = case_stack;
523 p->nesting_stack = nesting_stack;
524 p->nesting_depth = nesting_depth;
525 p->block_start_count = block_start_count;
526 p->last_expr_type = last_expr_type;
527 p->last_expr_value = last_expr_value;
528 p->expr_stmts_for_value = expr_stmts_for_value;
529 p->emit_filename = emit_filename;
530 p->emit_lineno = emit_lineno;
531 p->goto_fixup_chain = goto_fixup_chain;
535 restore_stmt_status (p)
538 block_stack = p->block_stack;
539 stack_block_stack = p->stack_block_stack;
540 cond_stack = p->cond_stack;
541 loop_stack = p->loop_stack;
542 case_stack = p->case_stack;
543 nesting_stack = p->nesting_stack;
544 nesting_depth = p->nesting_depth;
545 block_start_count = p->block_start_count;
546 last_expr_type = p->last_expr_type;
547 last_expr_value = p->last_expr_value;
548 expr_stmts_for_value = p->expr_stmts_for_value;
549 emit_filename = p->emit_filename;
550 emit_lineno = p->emit_lineno;
551 goto_fixup_chain = p->goto_fixup_chain;
554 /* Emit a no-op instruction. */
561 if (!output_bytecode)
563 last_insn = get_last_insn ();
565 && (GET_CODE (last_insn) == CODE_LABEL
566 || prev_real_insn (last_insn) == 0))
567 emit_insn (gen_nop ());
571 /* Return the rtx-label that corresponds to a LABEL_DECL,
572 creating it if necessary. */
578 if (TREE_CODE (label) != LABEL_DECL)
581 if (DECL_RTL (label))
582 return DECL_RTL (label);
584 return DECL_RTL (label) = gen_label_rtx ();
587 /* Add an unconditional jump to LABEL as the next sequential instruction. */
593 do_pending_stack_adjust ();
594 emit_jump_insn (gen_jump (label));
598 /* Emit code to jump to the address
599 specified by the pointer expression EXP. */
602 expand_computed_goto (exp)
607 bc_expand_expr (exp);
608 bc_emit_instruction (jumpP);
612 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
614 #ifdef POINTERS_EXTEND_UNSIGNED
615 x = convert_memory_address (Pmode, x);
619 do_pending_stack_adjust ();
620 emit_indirect_jump (x);
624 /* Handle goto statements and the labels that they can go to. */
626 /* Specify the location in the RTL code of a label LABEL,
627 which is a LABEL_DECL tree node.
629 This is used for the kind of label that the user can jump to with a
630 goto statement, and for alternatives of a switch or case statement.
631 RTL labels generated for loops and conditionals don't go through here;
632 they are generated directly at the RTL level, by other functions below.
634 Note that this has nothing to do with defining label *names*.
635 Languages vary in how they do that and what that even means. */
641 struct label_chain *p;
645 if (! DECL_RTL (label))
646 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
647 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
648 error ("multiply defined label");
652 do_pending_stack_adjust ();
653 emit_label (label_rtx (label));
654 if (DECL_NAME (label))
655 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
657 if (stack_block_stack != 0)
659 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
660 p->next = stack_block_stack->data.block.label_chain;
661 stack_block_stack->data.block.label_chain = p;
666 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
667 from nested functions. */
670 declare_nonlocal_label (label)
673 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
674 LABEL_PRESERVE_P (label_rtx (label)) = 1;
675 if (nonlocal_goto_handler_slot == 0)
677 nonlocal_goto_handler_slot
678 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
679 emit_stack_save (SAVE_NONLOCAL,
680 &nonlocal_goto_stack_level,
681 PREV_INSN (tail_recursion_reentry));
685 /* Generate RTL code for a `goto' statement with target label LABEL.
686 LABEL should be a LABEL_DECL tree node that was or will later be
687 defined with `expand_label'. */
697 expand_goto_internal (label, label_rtx (label), NULL_RTX);
701 /* Check for a nonlocal goto to a containing function. */
702 context = decl_function_context (label);
703 if (context != 0 && context != current_function_decl)
705 struct function *p = find_function_data (context);
706 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
709 p->has_nonlocal_label = 1;
710 current_function_has_nonlocal_goto = 1;
711 LABEL_REF_NONLOCAL_P (label_ref) = 1;
713 /* Copy the rtl for the slots so that they won't be shared in
714 case the virtual stack vars register gets instantiated differently
715 in the parent than in the child. */
717 #if HAVE_nonlocal_goto
718 if (HAVE_nonlocal_goto)
719 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
720 copy_rtx (p->nonlocal_goto_handler_slot),
721 copy_rtx (p->nonlocal_goto_stack_level),
728 /* Restore frame pointer for containing function.
729 This sets the actual hard register used for the frame pointer
730 to the location of the function's incoming static chain info.
731 The non-local goto handler will then adjust it to contain the
732 proper value and reload the argument pointer, if needed. */
733 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
735 /* We have now loaded the frame pointer hardware register with
736 the address of that corresponds to the start of the virtual
737 stack vars. So replace virtual_stack_vars_rtx in all
738 addresses we use with stack_pointer_rtx. */
740 /* Get addr of containing function's current nonlocal goto handler,
741 which will do any cleanups and then jump to the label. */
742 addr = copy_rtx (p->nonlocal_goto_handler_slot);
743 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
744 hard_frame_pointer_rtx));
746 /* Restore the stack pointer. Note this uses fp just restored. */
747 addr = p->nonlocal_goto_stack_level;
749 addr = replace_rtx (copy_rtx (addr),
750 virtual_stack_vars_rtx,
751 hard_frame_pointer_rtx);
753 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
755 /* Put in the static chain register the nonlocal label address. */
756 emit_move_insn (static_chain_rtx, label_ref);
757 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
759 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
760 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
761 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
762 emit_indirect_jump (temp);
766 expand_goto_internal (label, label_rtx (label), NULL_RTX);
769 /* Generate RTL code for a `goto' statement with target label BODY.
770 LABEL should be a LABEL_REF.
771 LAST_INSN, if non-0, is the rtx we should consider as the last
772 insn emitted (for the purposes of cleaning up a return). */
775 expand_goto_internal (body, label, last_insn)
780 struct nesting *block;
783 /* NOTICE! If a bytecode instruction other than `jump' is needed,
784 then the caller has to call bc_expand_goto_internal()
785 directly. This is rather an exceptional case, and there aren't
786 that many places where this is necessary. */
789 expand_goto_internal (body, label, last_insn);
793 if (GET_CODE (label) != CODE_LABEL)
796 /* If label has already been defined, we can tell now
797 whether and how we must alter the stack level. */
799 if (PREV_INSN (label) != 0)
801 /* Find the innermost pending block that contains the label.
802 (Check containment by comparing insn-uids.)
803 Then restore the outermost stack level within that block,
804 and do cleanups of all blocks contained in it. */
805 for (block = block_stack; block; block = block->next)
807 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
809 if (block->data.block.stack_level != 0)
810 stack_level = block->data.block.stack_level;
811 /* Execute the cleanups for blocks we are exiting. */
812 if (block->data.block.cleanups != 0)
814 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
815 do_pending_stack_adjust ();
821 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
822 the stack pointer. This one should be deleted as dead by flow. */
823 clear_pending_stack_adjust ();
824 do_pending_stack_adjust ();
825 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
828 if (body != 0 && DECL_TOO_LATE (body))
829 error ("jump to `%s' invalidly jumps into binding contour",
830 IDENTIFIER_POINTER (DECL_NAME (body)));
832 /* Label not yet defined: may need to put this goto
833 on the fixup list. */
834 else if (! expand_fixup (body, label, last_insn))
836 /* No fixup needed. Record that the label is the target
837 of at least one goto that has no fixup. */
839 TREE_ADDRESSABLE (body) = 1;
845 /* Generate a jump with OPCODE to the given bytecode LABEL which is
846 found within BODY. */
849 bc_expand_goto_internal (opcode, label, body)
850 enum bytecode_opcode opcode;
851 struct bc_label *label;
854 struct nesting *block;
855 int stack_level = -1;
857 /* If the label is defined, adjust the stack as necessary.
858 If it's not defined, we have to push the reference on the
864 /* Find the innermost pending block that contains the label.
865 (Check containment by comparing bytecode uids.) Then restore the
866 outermost stack level within that block. */
868 for (block = block_stack; block; block = block->next)
870 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
872 if (block->data.block.bc_stack_level)
873 stack_level = block->data.block.bc_stack_level;
875 /* Execute the cleanups for blocks we are exiting. */
876 if (block->data.block.cleanups != 0)
878 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
879 do_pending_stack_adjust ();
883 /* Restore the stack level. If we need to adjust the stack, we
884 must do so after the jump, since the jump may depend on
885 what's on the stack. Thus, any stack-modifying conditional
886 jumps (these are the only ones that rely on what's on the
887 stack) go into the fixup list. */
890 && stack_depth != stack_level
893 bc_expand_fixup (opcode, label, stack_level);
896 if (stack_level >= 0)
897 bc_adjust_stack (stack_depth - stack_level);
899 if (body && DECL_BIT_FIELD (body))
900 error ("jump to `%s' invalidly jumps into binding contour",
901 IDENTIFIER_POINTER (DECL_NAME (body)));
903 /* Emit immediate jump */
904 bc_emit_bytecode (opcode);
905 bc_emit_bytecode_labelref (label);
907 #ifdef DEBUG_PRINT_CODE
908 fputc ('\n', stderr);
913 /* Put goto in the fixup list */
914 bc_expand_fixup (opcode, label, stack_level);
917 /* Generate if necessary a fixup for a goto
918 whose target label in tree structure (if any) is TREE_LABEL
919 and whose target in rtl is RTL_LABEL.
921 If LAST_INSN is nonzero, we pretend that the jump appears
922 after insn LAST_INSN instead of at the current point in the insn stream.
924 The fixup will be used later to insert insns just before the goto.
925 Those insns will restore the stack level as appropriate for the
926 target label, and will (in the case of C++) also invoke any object
927 destructors which have to be invoked when we exit the scopes which
928 are exited by the goto.
930 Value is nonzero if a fixup is made. */
933 expand_fixup (tree_label, rtl_label, last_insn)
938 struct nesting *block, *end_block;
940 /* See if we can recognize which block the label will be output in.
941 This is possible in some very common cases.
942 If we succeed, set END_BLOCK to that block.
943 Otherwise, set it to 0. */
946 && (rtl_label == cond_stack->data.cond.endif_label
947 || rtl_label == cond_stack->data.cond.next_label))
948 end_block = cond_stack;
949 /* If we are in a loop, recognize certain labels which
950 are likely targets. This reduces the number of fixups
951 we need to create. */
953 && (rtl_label == loop_stack->data.loop.start_label
954 || rtl_label == loop_stack->data.loop.end_label
955 || rtl_label == loop_stack->data.loop.continue_label))
956 end_block = loop_stack;
960 /* Now set END_BLOCK to the binding level to which we will return. */
964 struct nesting *next_block = end_block->all;
967 /* First see if the END_BLOCK is inside the innermost binding level.
968 If so, then no cleanups or stack levels are relevant. */
969 while (next_block && next_block != block)
970 next_block = next_block->all;
975 /* Otherwise, set END_BLOCK to the innermost binding level
976 which is outside the relevant control-structure nesting. */
977 next_block = block_stack->next;
978 for (block = block_stack; block != end_block; block = block->all)
979 if (block == next_block)
980 next_block = next_block->next;
981 end_block = next_block;
984 /* Does any containing block have a stack level or cleanups?
985 If not, no fixup is needed, and that is the normal case
986 (the only case, for standard C). */
987 for (block = block_stack; block != end_block; block = block->next)
988 if (block->data.block.stack_level != 0
989 || block->data.block.cleanups != 0)
992 if (block != end_block)
994 /* Ok, a fixup is needed. Add a fixup to the list of such. */
995 struct goto_fixup *fixup
996 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
997 /* In case an old stack level is restored, make sure that comes
998 after any pending stack adjust. */
999 /* ?? If the fixup isn't to come at the present position,
1000 doing the stack adjust here isn't useful. Doing it with our
1001 settings at that location isn't useful either. Let's hope
1004 do_pending_stack_adjust ();
1005 fixup->target = tree_label;
1006 fixup->target_rtl = rtl_label;
1008 /* Create a BLOCK node and a corresponding matched set of
1009 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1010 this point. The notes will encapsulate any and all fixup
1011 code which we might later insert at this point in the insn
1012 stream. Also, the BLOCK node will be the parent (i.e. the
1013 `SUPERBLOCK') of any other BLOCK nodes which we might create
1014 later on when we are expanding the fixup code. */
1017 register rtx original_before_jump
1018 = last_insn ? last_insn : get_last_insn ();
1022 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1023 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1024 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1026 emit_insns_after (fixup->before_jump, original_before_jump);
1029 fixup->block_start_count = block_start_count;
1030 fixup->stack_level = 0;
1031 fixup->cleanup_list_list
1032 = (((block->data.block.outer_cleanups
1034 && block->data.block.outer_cleanups != empty_cleanup_list
1037 || block->data.block.cleanups)
1038 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1039 block->data.block.outer_cleanups)
1041 fixup->next = goto_fixup_chain;
1042 goto_fixup_chain = fixup;
1049 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1050 Make the fixup restore the stack level to STACK_LEVEL. */
1053 bc_expand_fixup (opcode, label, stack_level)
1054 enum bytecode_opcode opcode;
1055 struct bc_label *label;
1058 struct goto_fixup *fixup
1059 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1061 fixup->label = bc_get_bytecode_label ();
1062 fixup->bc_target = label;
1063 fixup->bc_stack_level = stack_level;
1064 fixup->bc_handled = FALSE;
1066 fixup->next = goto_fixup_chain;
1067 goto_fixup_chain = fixup;
1069 /* Insert a jump to the fixup code */
1070 bc_emit_bytecode (opcode);
1071 bc_emit_bytecode_labelref (fixup->label);
1073 #ifdef DEBUG_PRINT_CODE
1074 fputc ('\n', stderr);
1078 /* Expand any needed fixups in the outputmost binding level of the
1079 function. FIRST_INSN is the first insn in the function. */
1082 expand_fixups (first_insn)
1085 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1088 /* When exiting a binding contour, process all pending gotos requiring fixups.
1089 THISBLOCK is the structure that describes the block being exited.
1090 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1091 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1092 FIRST_INSN is the insn that began this contour.
1094 Gotos that jump out of this contour must restore the
1095 stack level and do the cleanups before actually jumping.
1097 DONT_JUMP_IN nonzero means report error there is a jump into this
1098 contour from before the beginning of the contour.
1099 This is also done if STACK_LEVEL is nonzero. */
1102 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1103 struct nesting *thisblock;
1109 register struct goto_fixup *f, *prev;
1111 if (output_bytecode)
1113 /* ??? The second arg is the bc stack level, which is not the same
1114 as STACK_LEVEL. I have no idea what should go here, so I'll
1116 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1120 /* F is the fixup we are considering; PREV is the previous one. */
1121 /* We run this loop in two passes so that cleanups of exited blocks
1122 are run first, and blocks that are exited are marked so
1125 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1127 /* Test for a fixup that is inactive because it is already handled. */
1128 if (f->before_jump == 0)
1130 /* Delete inactive fixup from the chain, if that is easy to do. */
1132 prev->next = f->next;
1134 /* Has this fixup's target label been defined?
1135 If so, we can finalize it. */
1136 else if (PREV_INSN (f->target_rtl) != 0)
1138 register rtx cleanup_insns;
1140 /* Get the first non-label after the label
1141 this goto jumps to. If that's before this scope begins,
1142 we don't have a jump into the scope. */
1143 rtx after_label = f->target_rtl;
1144 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1145 after_label = NEXT_INSN (after_label);
1147 /* If this fixup jumped into this contour from before the beginning
1148 of this contour, report an error. */
1149 /* ??? Bug: this does not detect jumping in through intermediate
1150 blocks that have stack levels or cleanups.
1151 It detects only a problem with the innermost block
1152 around the label. */
1154 && (dont_jump_in || stack_level || cleanup_list)
1155 /* If AFTER_LABEL is 0, it means the jump goes to the end
1156 of the rtl, which means it jumps into this scope. */
1157 && (after_label == 0
1158 || INSN_UID (first_insn) < INSN_UID (after_label))
1159 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1160 && ! DECL_REGISTER (f->target))
1162 error_with_decl (f->target,
1163 "label `%s' used before containing binding contour");
1164 /* Prevent multiple errors for one label. */
1165 DECL_REGISTER (f->target) = 1;
1168 /* We will expand the cleanups into a sequence of their own and
1169 then later on we will attach this new sequence to the insn
1170 stream just ahead of the actual jump insn. */
1174 /* Temporarily restore the lexical context where we will
1175 logically be inserting the fixup code. We do this for the
1176 sake of getting the debugging information right. */
1179 set_block (f->context);
1181 /* Expand the cleanups for blocks this jump exits. */
1182 if (f->cleanup_list_list)
1185 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1186 /* Marked elements correspond to blocks that have been closed.
1187 Do their cleanups. */
1188 if (TREE_ADDRESSABLE (lists)
1189 && TREE_VALUE (lists) != 0)
1191 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1192 /* Pop any pushes done in the cleanups,
1193 in case function is about to return. */
1194 do_pending_stack_adjust ();
1198 /* Restore stack level for the biggest contour that this
1199 jump jumps out of. */
1201 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1203 /* Finish up the sequence containing the insns which implement the
1204 necessary cleanups, and then attach that whole sequence to the
1205 insn stream just ahead of the actual jump insn. Attaching it
1206 at that point insures that any cleanups which are in fact
1207 implicit C++ object destructions (which must be executed upon
1208 leaving the block) appear (to the debugger) to be taking place
1209 in an area of the generated code where the object(s) being
1210 destructed are still "in scope". */
1212 cleanup_insns = get_insns ();
1216 emit_insns_after (cleanup_insns, f->before_jump);
1223 /* For any still-undefined labels, do the cleanups for this block now.
1224 We must do this now since items in the cleanup list may go out
1225 of scope when the block ends. */
1226 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1227 if (f->before_jump != 0
1228 && PREV_INSN (f->target_rtl) == 0
1229 /* Label has still not appeared. If we are exiting a block with
1230 a stack level to restore, that started before the fixup,
1231 mark this stack level as needing restoration
1232 when the fixup is later finalized. */
1234 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1235 means the label is undefined. That's erroneous, but possible. */
1236 && (thisblock->data.block.block_start_count
1237 <= f->block_start_count))
1239 tree lists = f->cleanup_list_list;
1242 for (; lists; lists = TREE_CHAIN (lists))
1243 /* If the following elt. corresponds to our containing block
1244 then the elt. must be for this block. */
1245 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1249 set_block (f->context);
1250 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1251 do_pending_stack_adjust ();
1252 cleanup_insns = get_insns ();
1256 = emit_insns_after (cleanup_insns, f->before_jump);
1258 TREE_VALUE (lists) = 0;
1262 f->stack_level = stack_level;
1267 /* When exiting a binding contour, process all pending gotos requiring fixups.
1268 Note: STACK_DEPTH is not altered.
1270 The arguments are currently not used in the bytecode compiler, but we may
1271 need them one day for languages other than C.
1273 THISBLOCK is the structure that describes the block being exited.
1274 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1275 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1276 FIRST_INSN is the insn that began this contour.
1278 Gotos that jump out of this contour must restore the
1279 stack level and do the cleanups before actually jumping.
1281 DONT_JUMP_IN nonzero means report error there is a jump into this
1282 contour from before the beginning of the contour.
1283 This is also done if STACK_LEVEL is nonzero. */
1286 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1287 struct nesting *thisblock;
1293 register struct goto_fixup *f, *prev;
1294 int saved_stack_depth;
1296 /* F is the fixup we are considering; PREV is the previous one. */
1298 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1300 /* Test for a fixup that is inactive because it is already handled. */
1301 if (f->before_jump == 0)
1303 /* Delete inactive fixup from the chain, if that is easy to do. */
1305 prev->next = f->next;
1308 /* Emit code to restore the stack and continue */
1309 bc_emit_bytecode_labeldef (f->label);
1311 /* Save stack_depth across call, since bc_adjust_stack () will alter
1312 the perceived stack depth via the instructions generated. */
1314 if (f->bc_stack_level >= 0)
1316 saved_stack_depth = stack_depth;
1317 bc_adjust_stack (stack_depth - f->bc_stack_level);
1318 stack_depth = saved_stack_depth;
1321 bc_emit_bytecode (jump);
1322 bc_emit_bytecode_labelref (f->bc_target);
1324 #ifdef DEBUG_PRINT_CODE
1325 fputc ('\n', stderr);
1329 goto_fixup_chain = NULL;
1332 /* Generate RTL for an asm statement (explicit assembler code).
1333 BODY is a STRING_CST node containing the assembler code text,
1334 or an ADDR_EXPR containing a STRING_CST. */
1340 if (output_bytecode)
1342 error ("`asm' is invalid when generating bytecode");
1346 if (TREE_CODE (body) == ADDR_EXPR)
1347 body = TREE_OPERAND (body, 0);
1349 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1350 TREE_STRING_POINTER (body)));
1354 /* Generate RTL for an asm statement with arguments.
1355 STRING is the instruction template.
1356 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1357 Each output or input has an expression in the TREE_VALUE and
1358 a constraint-string in the TREE_PURPOSE.
1359 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1360 that is clobbered by this insn.
1362 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1363 Some elements of OUTPUTS may be replaced with trees representing temporary
1364 values. The caller should copy those temporary values to the originally
1367 VOL nonzero means the insn is volatile; don't optimize it. */
1370 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1371 tree string, outputs, inputs, clobbers;
1376 rtvec argvec, constraints;
1378 int ninputs = list_length (inputs);
1379 int noutputs = list_length (outputs);
1383 /* Vector of RTX's of evaluated output operands. */
1384 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1385 /* The insn we have emitted. */
1388 if (output_bytecode)
1390 error ("`asm' is invalid when generating bytecode");
1394 /* Count the number of meaningful clobbered registers, ignoring what
1395 we would ignore later. */
1397 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1399 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1400 i = decode_reg_name (regname);
1401 if (i >= 0 || i == -4)
1404 error ("unknown register name `%s' in `asm'", regname);
1409 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1411 tree val = TREE_VALUE (tail);
1412 tree type = TREE_TYPE (val);
1415 int found_equal = 0;
1418 /* If there's an erroneous arg, emit no insn. */
1419 if (TREE_TYPE (val) == error_mark_node)
1422 /* Make sure constraint has `=' and does not have `+'. Also, see
1423 if it allows any register. Be liberal on the latter test, since
1424 the worst that happens if we get it wrong is we issue an error
1427 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1428 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1431 error ("output operand constraint contains `+'");
1438 case '?': case '!': case '*': case '%': case '&':
1439 case '0': case '1': case '2': case '3': case '4':
1440 case 'V': case 'm': case 'o': case '<': case '>':
1441 case 'E': case 'F': case 'G': case 'H': case 'X':
1442 case 's': case 'i': case 'n':
1443 case 'I': case 'J': case 'K': case 'L': case 'M':
1444 case 'N': case 'O': case 'P': case ',':
1445 #ifdef EXTRA_CONSTRAINT
1446 case 'Q': case 'R': case 'S': case 'T': case 'U':
1450 case 'p': case 'g': case 'r':
1458 error ("output operand constraint lacks `='");
1462 /* If an output operand is not a decl or indirect ref and our constraint
1463 allows a register, make a temporary to act as an intermediate.
1464 Make the asm insn write into that, then our caller will copy it to
1465 the real output operand. Likewise for promoted variables. */
1467 if (TREE_CODE (val) == INDIRECT_REF
1468 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1469 && ! (GET_CODE (DECL_RTL (val)) == REG
1470 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1474 mark_addressable (TREE_VALUE (tail));
1477 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1479 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1480 error ("output number %d not directly addressable", i);
1484 if (TYPE_MODE (type) == BLKmode)
1486 output_rtx[i] = assign_stack_temp (BLKmode,
1487 int_size_in_bytes (type), 0);
1488 MEM_IN_STRUCT_P (output_rtx[i]) = AGGREGATE_TYPE_P (type);
1491 output_rtx[i] = gen_reg_rtx (TYPE_MODE (type));
1493 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1497 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1499 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1503 /* Make vectors for the expression-rtx and constraint strings. */
1505 argvec = rtvec_alloc (ninputs);
1506 constraints = rtvec_alloc (ninputs);
1508 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1509 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1511 MEM_VOLATILE_P (body) = vol;
1513 /* Eval the inputs and put them into ARGVEC.
1514 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1517 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1521 /* If there's an erroneous arg, emit no insn,
1522 because the ASM_INPUT would get VOIDmode
1523 and that could cause a crash in reload. */
1524 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1526 if (TREE_PURPOSE (tail) == NULL_TREE)
1528 error ("hard register `%s' listed as input operand to `asm'",
1529 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1533 /* Make sure constraint has neither `=' nor `+'. */
1535 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)); j++)
1536 if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '='
1537 || TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] == '+')
1539 error ("input operand constraint contains `%c'",
1540 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1544 XVECEXP (body, 3, i) /* argvec */
1545 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1546 if (CONSTANT_P (XVECEXP (body, 3, i))
1547 && ! general_operand (XVECEXP (body, 3, i),
1548 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1549 XVECEXP (body, 3, i)
1550 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1551 XVECEXP (body, 3, i));
1552 XVECEXP (body, 4, i) /* constraints */
1553 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1554 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1558 /* Protect all the operands from the queue,
1559 now that they have all been evaluated. */
1561 for (i = 0; i < ninputs; i++)
1562 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1564 for (i = 0; i < noutputs; i++)
1565 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1567 /* Now, for each output, construct an rtx
1568 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1569 ARGVEC CONSTRAINTS))
1570 If there is more than one, put them inside a PARALLEL. */
1572 if (noutputs == 1 && nclobbers == 0)
1574 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1575 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1577 else if (noutputs == 0 && nclobbers == 0)
1579 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1580 insn = emit_insn (body);
1586 if (num == 0) num = 1;
1587 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1589 /* For each output operand, store a SET. */
1591 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1593 XVECEXP (body, 0, i)
1594 = gen_rtx (SET, VOIDmode,
1596 gen_rtx (ASM_OPERANDS, VOIDmode,
1597 TREE_STRING_POINTER (string),
1598 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1599 i, argvec, constraints,
1601 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1604 /* If there are no outputs (but there are some clobbers)
1605 store the bare ASM_OPERANDS into the PARALLEL. */
1608 XVECEXP (body, 0, i++) = obody;
1610 /* Store (clobber REG) for each clobbered register specified. */
1612 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1614 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1615 int j = decode_reg_name (regname);
1619 if (j == -3) /* `cc', which is not a register */
1622 if (j == -4) /* `memory', don't cache memory across asm */
1624 XVECEXP (body, 0, i++)
1625 = gen_rtx (CLOBBER, VOIDmode,
1626 gen_rtx (MEM, BLKmode,
1627 gen_rtx (SCRATCH, VOIDmode, 0)));
1631 /* Ignore unknown register, error already signalled. */
1635 /* Use QImode since that's guaranteed to clobber just one reg. */
1636 XVECEXP (body, 0, i++)
1637 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1640 insn = emit_insn (body);
1646 /* Generate RTL to evaluate the expression EXP
1647 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1650 expand_expr_stmt (exp)
1653 if (output_bytecode)
1655 int org_stack_depth = stack_depth;
1657 bc_expand_expr (exp);
1659 /* Restore stack depth */
1660 if (stack_depth < org_stack_depth)
1663 bc_emit_instruction (drop);
1665 last_expr_type = TREE_TYPE (exp);
1669 /* If -W, warn about statements with no side effects,
1670 except for an explicit cast to void (e.g. for assert()), and
1671 except inside a ({...}) where they may be useful. */
1672 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1674 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1675 && !(TREE_CODE (exp) == CONVERT_EXPR
1676 && TREE_TYPE (exp) == void_type_node))
1677 warning_with_file_and_line (emit_filename, emit_lineno,
1678 "statement with no effect");
1679 else if (warn_unused)
1680 warn_if_unused_value (exp);
1683 /* If EXP is of function type and we are expanding statements for
1684 value, convert it to pointer-to-function. */
1685 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1686 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1688 last_expr_type = TREE_TYPE (exp);
1689 if (! flag_syntax_only)
1690 last_expr_value = expand_expr (exp,
1691 (expr_stmts_for_value
1692 ? NULL_RTX : const0_rtx),
1695 /* If all we do is reference a volatile value in memory,
1696 copy it to a register to be sure it is actually touched. */
1697 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1698 && TREE_THIS_VOLATILE (exp))
1700 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1702 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1703 copy_to_reg (last_expr_value);
1706 rtx lab = gen_label_rtx ();
1708 /* Compare the value with itself to reference it. */
1709 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1710 expand_expr (TYPE_SIZE (last_expr_type),
1711 NULL_RTX, VOIDmode, 0),
1713 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1714 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1719 /* If this expression is part of a ({...}) and is in memory, we may have
1720 to preserve temporaries. */
1721 preserve_temp_slots (last_expr_value);
1723 /* Free any temporaries used to evaluate this expression. Any temporary
1724 used as a result of this expression will already have been preserved
1731 /* Warn if EXP contains any computations whose results are not used.
1732 Return 1 if a warning is printed; 0 otherwise. */
1735 warn_if_unused_value (exp)
1738 if (TREE_USED (exp))
1741 switch (TREE_CODE (exp))
1743 case PREINCREMENT_EXPR:
1744 case POSTINCREMENT_EXPR:
1745 case PREDECREMENT_EXPR:
1746 case POSTDECREMENT_EXPR:
1751 case METHOD_CALL_EXPR:
1753 case WITH_CLEANUP_EXPR:
1755 /* We don't warn about COND_EXPR because it may be a useful
1756 construct if either arm contains a side effect. */
1761 /* For a binding, warn if no side effect within it. */
1762 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1765 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1767 case TRUTH_ORIF_EXPR:
1768 case TRUTH_ANDIF_EXPR:
1769 /* In && or ||, warn if 2nd operand has no side effect. */
1770 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1773 if (TREE_NO_UNUSED_WARNING (exp))
1775 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1777 /* Let people do `(foo (), 0)' without a warning. */
1778 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1780 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1784 case NON_LVALUE_EXPR:
1785 /* Don't warn about values cast to void. */
1786 if (TREE_TYPE (exp) == void_type_node)
1788 /* Don't warn about conversions not explicit in the user's program. */
1789 if (TREE_NO_UNUSED_WARNING (exp))
1791 /* Assignment to a cast usually results in a cast of a modify.
1792 Don't complain about that. There can be an arbitrary number of
1793 casts before the modify, so we must loop until we find the first
1794 non-cast expression and then test to see if that is a modify. */
1796 tree tem = TREE_OPERAND (exp, 0);
1798 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1799 tem = TREE_OPERAND (tem, 0);
1801 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1802 || TREE_CODE (tem) == CALL_EXPR)
1808 /* Don't warn about automatic dereferencing of references, since
1809 the user cannot control it. */
1810 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1811 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1812 /* ... fall through ... */
1815 /* Referencing a volatile value is a side effect, so don't warn. */
1816 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1817 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1818 && TREE_THIS_VOLATILE (exp))
1821 warning_with_file_and_line (emit_filename, emit_lineno,
1822 "value computed is not used");
1827 /* Clear out the memory of the last expression evaluated. */
1835 /* Begin a statement which will return a value.
1836 Return the RTL_EXPR for this statement expr.
1837 The caller must save that value and pass it to expand_end_stmt_expr. */
1840 expand_start_stmt_expr ()
1845 /* When generating bytecode just note down the stack depth */
1846 if (output_bytecode)
1847 return (build_int_2 (stack_depth, 0));
1849 /* Make the RTL_EXPR node temporary, not momentary,
1850 so that rtl_expr_chain doesn't become garbage. */
1851 momentary = suspend_momentary ();
1852 t = make_node (RTL_EXPR);
1853 resume_momentary (momentary);
1854 start_sequence_for_rtl_expr (t);
1856 expr_stmts_for_value++;
1860 /* Restore the previous state at the end of a statement that returns a value.
1861 Returns a tree node representing the statement's value and the
1862 insns to compute the value.
1864 The nodes of that expression have been freed by now, so we cannot use them.
1865 But we don't want to do that anyway; the expression has already been
1866 evaluated and now we just want to use the value. So generate a RTL_EXPR
1867 with the proper type and RTL value.
1869 If the last substatement was not an expression,
1870 return something with type `void'. */
1873 expand_end_stmt_expr (t)
1876 if (output_bytecode)
1882 /* At this point, all expressions have been evaluated in order.
1883 However, all expression values have been popped when evaluated,
1884 which means we have to recover the last expression value. This is
1885 the last value removed by means of a `drop' instruction. Instead
1886 of adding code to inhibit dropping the last expression value, it
1887 is here recovered by undoing the `drop'. Since `drop' is
1888 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1891 bc_adjust_stack (-1);
1893 if (!last_expr_type)
1894 last_expr_type = void_type_node;
1896 t = make_node (RTL_EXPR);
1897 TREE_TYPE (t) = last_expr_type;
1898 RTL_EXPR_RTL (t) = NULL;
1899 RTL_EXPR_SEQUENCE (t) = NULL;
1901 /* Don't consider deleting this expr or containing exprs at tree level. */
1902 TREE_THIS_VOLATILE (t) = 1;
1910 if (last_expr_type == 0)
1912 last_expr_type = void_type_node;
1913 last_expr_value = const0_rtx;
1915 else if (last_expr_value == 0)
1916 /* There are some cases where this can happen, such as when the
1917 statement is void type. */
1918 last_expr_value = const0_rtx;
1919 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1920 /* Remove any possible QUEUED. */
1921 last_expr_value = protect_from_queue (last_expr_value, 0);
1925 TREE_TYPE (t) = last_expr_type;
1926 RTL_EXPR_RTL (t) = last_expr_value;
1927 RTL_EXPR_SEQUENCE (t) = get_insns ();
1929 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1933 /* Don't consider deleting this expr or containing exprs at tree level. */
1934 TREE_SIDE_EFFECTS (t) = 1;
1935 /* Propagate volatility of the actual RTL expr. */
1936 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1939 expr_stmts_for_value--;
1944 /* Generate RTL for the start of an if-then. COND is the expression
1945 whose truth should be tested.
1947 If EXITFLAG is nonzero, this conditional is visible to
1948 `exit_something'. */
1951 expand_start_cond (cond, exitflag)
1955 struct nesting *thiscond = ALLOC_NESTING ();
1957 /* Make an entry on cond_stack for the cond we are entering. */
1959 thiscond->next = cond_stack;
1960 thiscond->all = nesting_stack;
1961 thiscond->depth = ++nesting_depth;
1962 thiscond->data.cond.next_label = gen_label_rtx ();
1963 /* Before we encounter an `else', we don't need a separate exit label
1964 unless there are supposed to be exit statements
1965 to exit this conditional. */
1966 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1967 thiscond->data.cond.endif_label = thiscond->exit_label;
1968 cond_stack = thiscond;
1969 nesting_stack = thiscond;
1971 if (output_bytecode)
1972 bc_expand_start_cond (cond, exitflag);
1974 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1977 /* Generate RTL between then-clause and the elseif-clause
1978 of an if-then-elseif-.... */
1981 expand_start_elseif (cond)
1984 if (cond_stack->data.cond.endif_label == 0)
1985 cond_stack->data.cond.endif_label = gen_label_rtx ();
1986 emit_jump (cond_stack->data.cond.endif_label);
1987 emit_label (cond_stack->data.cond.next_label);
1988 cond_stack->data.cond.next_label = gen_label_rtx ();
1989 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1992 /* Generate RTL between the then-clause and the else-clause
1993 of an if-then-else. */
1996 expand_start_else ()
1998 if (cond_stack->data.cond.endif_label == 0)
1999 cond_stack->data.cond.endif_label = gen_label_rtx ();
2001 if (output_bytecode)
2003 bc_expand_start_else ();
2007 emit_jump (cond_stack->data.cond.endif_label);
2008 emit_label (cond_stack->data.cond.next_label);
2009 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2012 /* After calling expand_start_else, turn this "else" into an "else if"
2013 by providing another condition. */
2016 expand_elseif (cond)
2019 cond_stack->data.cond.next_label = gen_label_rtx ();
2020 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2023 /* Generate RTL for the end of an if-then.
2024 Pop the record for it off of cond_stack. */
2029 struct nesting *thiscond = cond_stack;
2031 if (output_bytecode)
2032 bc_expand_end_cond ();
2035 do_pending_stack_adjust ();
2036 if (thiscond->data.cond.next_label)
2037 emit_label (thiscond->data.cond.next_label);
2038 if (thiscond->data.cond.endif_label)
2039 emit_label (thiscond->data.cond.endif_label);
2042 POPSTACK (cond_stack);
2047 /* Generate code for the start of an if-then. COND is the expression
2048 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2049 is to be visible to exit_something. It is assumed that the caller
2050 has pushed the previous context on the cond stack. */
2053 bc_expand_start_cond (cond, exitflag)
2057 struct nesting *thiscond = cond_stack;
2059 thiscond->data.case_stmt.nominal_type = cond;
2061 thiscond->exit_label = gen_label_rtx ();
2062 bc_expand_expr (cond);
2063 bc_emit_bytecode (xjumpifnot);
2064 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2066 #ifdef DEBUG_PRINT_CODE
2067 fputc ('\n', stderr);
2071 /* Generate the label for the end of an if with
2075 bc_expand_end_cond ()
2077 struct nesting *thiscond = cond_stack;
2079 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2082 /* Generate code for the start of the else- clause of
2086 bc_expand_start_else ()
2088 struct nesting *thiscond = cond_stack;
2090 thiscond->data.cond.endif_label = thiscond->exit_label;
2091 thiscond->exit_label = gen_label_rtx ();
2092 bc_emit_bytecode (jump);
2093 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2095 #ifdef DEBUG_PRINT_CODE
2096 fputc ('\n', stderr);
2099 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2102 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2103 loop should be exited by `exit_something'. This is a loop for which
2104 `expand_continue' will jump to the top of the loop.
2106 Make an entry on loop_stack to record the labels associated with
2110 expand_start_loop (exit_flag)
2113 register struct nesting *thisloop = ALLOC_NESTING ();
2115 /* Make an entry on loop_stack for the loop we are entering. */
2117 thisloop->next = loop_stack;
2118 thisloop->all = nesting_stack;
2119 thisloop->depth = ++nesting_depth;
2120 thisloop->data.loop.start_label = gen_label_rtx ();
2121 thisloop->data.loop.end_label = gen_label_rtx ();
2122 thisloop->data.loop.alt_end_label = 0;
2123 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2124 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2125 loop_stack = thisloop;
2126 nesting_stack = thisloop;
2128 if (output_bytecode)
2130 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2134 do_pending_stack_adjust ();
2136 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2137 emit_label (thisloop->data.loop.start_label);
2142 /* Like expand_start_loop but for a loop where the continuation point
2143 (for expand_continue_loop) will be specified explicitly. */
2146 expand_start_loop_continue_elsewhere (exit_flag)
2149 struct nesting *thisloop = expand_start_loop (exit_flag);
2150 loop_stack->data.loop.continue_label = gen_label_rtx ();
2154 /* Specify the continuation point for a loop started with
2155 expand_start_loop_continue_elsewhere.
2156 Use this at the point in the code to which a continue statement
2160 expand_loop_continue_here ()
2162 if (output_bytecode)
2164 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2167 do_pending_stack_adjust ();
2168 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2169 emit_label (loop_stack->data.loop.continue_label);
2175 bc_expand_end_loop ()
2177 struct nesting *thisloop = loop_stack;
2179 bc_emit_bytecode (jump);
2180 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2182 #ifdef DEBUG_PRINT_CODE
2183 fputc ('\n', stderr);
2186 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2187 POPSTACK (loop_stack);
2192 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2193 Pop the block off of loop_stack. */
2199 register rtx start_label;
2200 rtx last_test_insn = 0;
2203 if (output_bytecode)
2205 bc_expand_end_loop ();
2209 insn = get_last_insn ();
2210 start_label = loop_stack->data.loop.start_label;
2212 /* Mark the continue-point at the top of the loop if none elsewhere. */
2213 if (start_label == loop_stack->data.loop.continue_label)
2214 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2216 do_pending_stack_adjust ();
2218 /* If optimizing, perhaps reorder the loop. If the loop
2219 starts with a conditional exit, roll that to the end
2220 where it will optimize together with the jump back.
2222 We look for the last conditional branch to the exit that we encounter
2223 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2224 branch to the exit first, use it.
2226 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2227 because moving them is not valid. */
2231 ! (GET_CODE (insn) == JUMP_INSN
2232 && GET_CODE (PATTERN (insn)) == SET
2233 && SET_DEST (PATTERN (insn)) == pc_rtx
2234 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2236 /* Scan insns from the top of the loop looking for a qualified
2237 conditional exit. */
2238 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2239 insn = NEXT_INSN (insn))
2241 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2244 if (GET_CODE (insn) == NOTE
2245 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2246 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2249 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2252 if (last_test_insn && num_insns > 30)
2255 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2256 && SET_DEST (PATTERN (insn)) == pc_rtx
2257 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2258 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2259 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2260 == loop_stack->data.loop.end_label)
2261 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2262 == loop_stack->data.loop.alt_end_label)))
2263 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2264 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2265 == loop_stack->data.loop.end_label)
2266 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2267 == loop_stack->data.loop.alt_end_label)))))
2268 last_test_insn = insn;
2270 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2271 && GET_CODE (PATTERN (insn)) == SET
2272 && SET_DEST (PATTERN (insn)) == pc_rtx
2273 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2274 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2275 == loop_stack->data.loop.end_label)
2276 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2277 == loop_stack->data.loop.alt_end_label)))
2278 /* Include BARRIER. */
2279 last_test_insn = NEXT_INSN (insn);
2282 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2284 /* We found one. Move everything from there up
2285 to the end of the loop, and add a jump into the loop
2286 to jump to there. */
2287 register rtx newstart_label = gen_label_rtx ();
2288 register rtx start_move = start_label;
2290 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2291 then we want to move this note also. */
2292 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2293 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2294 == NOTE_INSN_LOOP_CONT))
2295 start_move = PREV_INSN (start_move);
2297 emit_label_after (newstart_label, PREV_INSN (start_move));
2298 reorder_insns (start_move, last_test_insn, get_last_insn ());
2299 emit_jump_insn_after (gen_jump (start_label),
2300 PREV_INSN (newstart_label));
2301 emit_barrier_after (PREV_INSN (newstart_label));
2302 start_label = newstart_label;
2306 emit_jump (start_label);
2307 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2308 emit_label (loop_stack->data.loop.end_label);
2310 POPSTACK (loop_stack);
2315 /* Generate a jump to the current loop's continue-point.
2316 This is usually the top of the loop, but may be specified
2317 explicitly elsewhere. If not currently inside a loop,
2318 return 0 and do nothing; caller will print an error message. */
2321 expand_continue_loop (whichloop)
2322 struct nesting *whichloop;
2326 whichloop = loop_stack;
2329 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2334 /* Generate a jump to exit the current loop. If not currently inside a loop,
2335 return 0 and do nothing; caller will print an error message. */
2338 expand_exit_loop (whichloop)
2339 struct nesting *whichloop;
2343 whichloop = loop_stack;
2346 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2350 /* Generate a conditional jump to exit the current loop if COND
2351 evaluates to zero. If not currently inside a loop,
2352 return 0 and do nothing; caller will print an error message. */
2355 expand_exit_loop_if_false (whichloop, cond)
2356 struct nesting *whichloop;
2361 whichloop = loop_stack;
2364 if (output_bytecode)
2366 bc_expand_expr (cond);
2367 bc_expand_goto_internal (xjumpifnot,
2368 BYTECODE_BC_LABEL (whichloop->exit_label),
2373 /* In order to handle fixups, we actually create a conditional jump
2374 around a unconditional branch to exit the loop. If fixups are
2375 necessary, they go before the unconditional branch. */
2377 rtx label = gen_label_rtx ();
2380 do_jump (cond, NULL_RTX, label);
2381 last_insn = get_last_insn ();
2382 if (GET_CODE (last_insn) == CODE_LABEL)
2383 whichloop->data.loop.alt_end_label = last_insn;
2384 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2392 /* Return non-zero if we should preserve sub-expressions as separate
2393 pseudos. We never do so if we aren't optimizing. We always do so
2394 if -fexpensive-optimizations.
2396 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2397 the loop may still be a small one. */
2400 preserve_subexpressions_p ()
2404 if (flag_expensive_optimizations)
2407 if (optimize == 0 || loop_stack == 0)
2410 insn = get_last_insn_anywhere ();
2413 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2414 < n_non_fixed_regs * 3));
2418 /* Generate a jump to exit the current loop, conditional, binding contour
2419 or case statement. Not all such constructs are visible to this function,
2420 only those started with EXIT_FLAG nonzero. Individual languages use
2421 the EXIT_FLAG parameter to control which kinds of constructs you can
2424 If not currently inside anything that can be exited,
2425 return 0 and do nothing; caller will print an error message. */
2428 expand_exit_something ()
2432 for (n = nesting_stack; n; n = n->all)
2433 if (n->exit_label != 0)
2435 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2442 /* Generate RTL to return from the current function, with no value.
2443 (That is, we do not do anything about returning any value.) */
2446 expand_null_return ()
2448 struct nesting *block = block_stack;
2451 if (output_bytecode)
2453 bc_emit_instruction (ret);
2457 /* Does any pending block have cleanups? */
2459 while (block && block->data.block.cleanups == 0)
2460 block = block->next;
2462 /* If yes, use a goto to return, since that runs cleanups. */
2464 expand_null_return_1 (last_insn, block != 0);
2467 /* Generate RTL to return from the current function, with value VAL. */
2470 expand_value_return (val)
2473 struct nesting *block = block_stack;
2474 rtx last_insn = get_last_insn ();
2475 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2477 /* Copy the value to the return location
2478 unless it's already there. */
2480 if (return_reg != val)
2482 #ifdef PROMOTE_FUNCTION_RETURN
2483 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2484 int unsignedp = TREE_UNSIGNED (type);
2485 enum machine_mode mode
2486 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2489 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2490 convert_move (return_reg, val, unsignedp);
2493 emit_move_insn (return_reg, val);
2495 if (GET_CODE (return_reg) == REG
2496 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2497 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2499 /* Does any pending block have cleanups? */
2501 while (block && block->data.block.cleanups == 0)
2502 block = block->next;
2504 /* If yes, use a goto to return, since that runs cleanups.
2505 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2507 expand_null_return_1 (last_insn, block != 0);
2510 /* Output a return with no value. If LAST_INSN is nonzero,
2511 pretend that the return takes place after LAST_INSN.
2512 If USE_GOTO is nonzero then don't use a return instruction;
2513 go to the return label instead. This causes any cleanups
2514 of pending blocks to be executed normally. */
2517 expand_null_return_1 (last_insn, use_goto)
2521 rtx end_label = cleanup_label ? cleanup_label : return_label;
2523 clear_pending_stack_adjust ();
2524 do_pending_stack_adjust ();
2527 /* PCC-struct return always uses an epilogue. */
2528 if (current_function_returns_pcc_struct || use_goto)
2531 end_label = return_label = gen_label_rtx ();
2532 expand_goto_internal (NULL_TREE, end_label, last_insn);
2536 /* Otherwise output a simple return-insn if one is available,
2537 unless it won't do the job. */
2539 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2541 emit_jump_insn (gen_return ());
2547 /* Otherwise jump to the epilogue. */
2548 expand_goto_internal (NULL_TREE, end_label, last_insn);
2551 /* Generate RTL to evaluate the expression RETVAL and return it
2552 from the current function. */
2555 expand_return (retval)
2558 /* If there are any cleanups to be performed, then they will
2559 be inserted following LAST_INSN. It is desirable
2560 that the last_insn, for such purposes, should be the
2561 last insn before computing the return value. Otherwise, cleanups
2562 which call functions can clobber the return value. */
2563 /* ??? rms: I think that is erroneous, because in C++ it would
2564 run destructors on variables that might be used in the subsequent
2565 computation of the return value. */
2567 register rtx val = 0;
2571 struct nesting *block;
2573 /* Bytecode returns are quite simple, just leave the result on the
2574 arithmetic stack. */
2575 if (output_bytecode)
2577 bc_expand_expr (retval);
2578 bc_emit_instruction (ret);
2582 /* If function wants no value, give it none. */
2583 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2585 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2587 expand_null_return ();
2591 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2592 /* This is not sufficient. We also need to watch for cleanups of the
2593 expression we are about to expand. Unfortunately, we cannot know
2594 if it has cleanups until we expand it, and we want to change how we
2595 expand it depending upon if we need cleanups. We can't win. */
2597 cleanups = any_pending_cleanups (1);
2602 if (TREE_CODE (retval) == RESULT_DECL)
2603 retval_rhs = retval;
2604 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2605 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2606 retval_rhs = TREE_OPERAND (retval, 1);
2607 else if (TREE_TYPE (retval) == void_type_node)
2608 /* Recognize tail-recursive call to void function. */
2609 retval_rhs = retval;
2611 retval_rhs = NULL_TREE;
2613 /* Only use `last_insn' if there are cleanups which must be run. */
2614 if (cleanups || cleanup_label != 0)
2615 last_insn = get_last_insn ();
2617 /* Distribute return down conditional expr if either of the sides
2618 may involve tail recursion (see test below). This enhances the number
2619 of tail recursions we see. Don't do this always since it can produce
2620 sub-optimal code in some cases and we distribute assignments into
2621 conditional expressions when it would help. */
2623 if (optimize && retval_rhs != 0
2624 && frame_offset == 0
2625 && TREE_CODE (retval_rhs) == COND_EXPR
2626 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2627 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2629 rtx label = gen_label_rtx ();
2632 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2633 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2634 DECL_RESULT (current_function_decl),
2635 TREE_OPERAND (retval_rhs, 1));
2636 TREE_SIDE_EFFECTS (expr) = 1;
2637 expand_return (expr);
2640 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2641 DECL_RESULT (current_function_decl),
2642 TREE_OPERAND (retval_rhs, 2));
2643 TREE_SIDE_EFFECTS (expr) = 1;
2644 expand_return (expr);
2648 /* For tail-recursive call to current function,
2649 just jump back to the beginning.
2650 It's unsafe if any auto variable in this function
2651 has its address taken; for simplicity,
2652 require stack frame to be empty. */
2653 if (optimize && retval_rhs != 0
2654 && frame_offset == 0
2655 && TREE_CODE (retval_rhs) == CALL_EXPR
2656 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2657 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2658 /* Finish checking validity, and if valid emit code
2659 to set the argument variables for the new call. */
2660 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2661 DECL_ARGUMENTS (current_function_decl)))
2663 if (tail_recursion_label == 0)
2665 tail_recursion_label = gen_label_rtx ();
2666 emit_label_after (tail_recursion_label,
2667 tail_recursion_reentry);
2670 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2675 /* This optimization is safe if there are local cleanups
2676 because expand_null_return takes care of them.
2677 ??? I think it should also be safe when there is a cleanup label,
2678 because expand_null_return takes care of them, too.
2679 Any reason why not? */
2680 if (HAVE_return && cleanup_label == 0
2681 && ! current_function_returns_pcc_struct
2682 && BRANCH_COST <= 1)
2684 /* If this is return x == y; then generate
2685 if (x == y) return 1; else return 0;
2686 if we can do it with explicit return insns and
2687 branches are cheap. */
2689 switch (TREE_CODE (retval_rhs))
2697 case TRUTH_ANDIF_EXPR:
2698 case TRUTH_ORIF_EXPR:
2699 case TRUTH_AND_EXPR:
2701 case TRUTH_NOT_EXPR:
2702 case TRUTH_XOR_EXPR:
2703 op0 = gen_label_rtx ();
2704 jumpifnot (retval_rhs, op0);
2705 expand_value_return (const1_rtx);
2707 expand_value_return (const0_rtx);
2711 #endif /* HAVE_return */
2713 /* If the result is an aggregate that is being returned in one (or more)
2714 registers, load the registers here. The compiler currently can't handle
2715 copying a BLKmode value into registers. We could put this code in a
2716 more general area (for use by everyone instead of just function
2717 call/return), but until this feature is generally usable it is kept here
2718 (and in expand_call). The value must go into a pseudo in case there
2719 are cleanups that will clobber the real return register. */
2722 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2723 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2725 int i, bitpos, xbitpos;
2726 int big_endian_correction = 0;
2727 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2728 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2729 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2730 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2731 rtx result_reg, src, dst;
2732 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2733 enum machine_mode tmpmode, result_reg_mode;
2735 /* Structures whose size is not a multiple of a word are aligned
2736 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2737 machine, this means we must skip the empty high order bytes when
2738 calculating the bit offset. */
2739 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2740 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2743 /* Copy the structure BITSIZE bits at a time. */
2744 for (bitpos = 0, xbitpos = big_endian_correction;
2745 bitpos < bytes * BITS_PER_UNIT;
2746 bitpos += bitsize, xbitpos += bitsize)
2748 /* We need a new destination pseudo each time xbitpos is
2749 on a word boundary and when xbitpos == big_endian_corrction
2750 (the first time through). */
2751 if (xbitpos % BITS_PER_WORD == 0
2752 || xbitpos == big_endian_correction)
2754 /* Generate an appropriate register. */
2755 dst = gen_reg_rtx (word_mode);
2756 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2758 /* Clobber the destination before we move anything into it. */
2759 emit_insn (gen_rtx (CLOBBER, VOIDmode, dst));
2762 /* We need a new source operand each time bitpos is on a word
2764 if (bitpos % BITS_PER_WORD == 0)
2765 src = operand_subword_force (result_val,
2766 bitpos / BITS_PER_WORD,
2769 /* Use bitpos for the source extraction (left justified) and
2770 xbitpos for the destination store (right justified). */
2771 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2772 extract_bit_field (src, bitsize,
2773 bitpos % BITS_PER_WORD, 1,
2774 NULL_RTX, word_mode,
2776 bitsize / BITS_PER_UNIT,
2778 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2781 /* Find the smallest integer mode large enough to hold the
2782 entire structure and use that mode instead of BLKmode
2783 on the USE insn for the return register. */
2784 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2785 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2786 tmpmode != MAX_MACHINE_MODE;
2787 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2789 /* Have we found a large enough mode? */
2790 if (GET_MODE_SIZE (tmpmode) >= bytes)
2794 /* No suitable mode found. */
2795 if (tmpmode == MAX_MACHINE_MODE)
2798 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2800 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2801 result_reg_mode = word_mode;
2803 result_reg_mode = tmpmode;
2804 result_reg = gen_reg_rtx (result_reg_mode);
2806 /* Now that the value is in pseudos, copy it to the result reg(s). */
2809 for (i = 0; i < n_regs; i++)
2810 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2813 if (tmpmode != result_reg_mode)
2814 result_reg = gen_lowpart (tmpmode, result_reg);
2816 expand_value_return (result_reg);
2820 && TREE_TYPE (retval_rhs) != void_type_node
2821 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2823 /* Calculate the return value into a pseudo reg. */
2824 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2826 /* All temporaries have now been used. */
2828 /* Return the calculated value, doing cleanups first. */
2829 expand_value_return (val);
2833 /* No cleanups or no hard reg used;
2834 calculate value into hard return reg. */
2835 expand_expr (retval, const0_rtx, VOIDmode, 0);
2838 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2842 /* Return 1 if the end of the generated RTX is not a barrier.
2843 This means code already compiled can drop through. */
2846 drop_through_at_end_p ()
2848 rtx insn = get_last_insn ();
2849 while (insn && GET_CODE (insn) == NOTE)
2850 insn = PREV_INSN (insn);
2851 return insn && GET_CODE (insn) != BARRIER;
2854 /* Emit code to alter this function's formal parms for a tail-recursive call.
2855 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2856 FORMALS is the chain of decls of formals.
2857 Return 1 if this can be done;
2858 otherwise return 0 and do not emit any code. */
2861 tail_recursion_args (actuals, formals)
2862 tree actuals, formals;
2864 register tree a = actuals, f = formals;
2866 register rtx *argvec;
2868 /* Check that number and types of actuals are compatible
2869 with the formals. This is not always true in valid C code.
2870 Also check that no formal needs to be addressable
2871 and that all formals are scalars. */
2873 /* Also count the args. */
2875 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2877 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2879 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2882 if (a != 0 || f != 0)
2885 /* Compute all the actuals. */
2887 argvec = (rtx *) alloca (i * sizeof (rtx));
2889 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2890 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2892 /* Find which actual values refer to current values of previous formals.
2893 Copy each of them now, before any formal is changed. */
2895 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2899 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2900 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2901 { copy = 1; break; }
2903 argvec[i] = copy_to_reg (argvec[i]);
2906 /* Store the values of the actuals into the formals. */
2908 for (f = formals, a = actuals, i = 0; f;
2909 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2911 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2912 emit_move_insn (DECL_RTL (f), argvec[i]);
2914 convert_move (DECL_RTL (f), argvec[i],
2915 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2922 /* Generate the RTL code for entering a binding contour.
2923 The variables are declared one by one, by calls to `expand_decl'.
2925 EXIT_FLAG is nonzero if this construct should be visible to
2926 `exit_something'. */
2929 expand_start_bindings (exit_flag)
2932 struct nesting *thisblock = ALLOC_NESTING ();
2933 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2935 /* Make an entry on block_stack for the block we are entering. */
2937 thisblock->next = block_stack;
2938 thisblock->all = nesting_stack;
2939 thisblock->depth = ++nesting_depth;
2940 thisblock->data.block.stack_level = 0;
2941 thisblock->data.block.cleanups = 0;
2942 thisblock->data.block.function_call_count = 0;
2946 if (block_stack->data.block.cleanups == NULL_TREE
2947 && (block_stack->data.block.outer_cleanups == NULL_TREE
2948 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2949 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2951 thisblock->data.block.outer_cleanups
2952 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2953 block_stack->data.block.outer_cleanups);
2956 thisblock->data.block.outer_cleanups = 0;
2960 && !(block_stack->data.block.cleanups == NULL_TREE
2961 && block_stack->data.block.outer_cleanups == NULL_TREE))
2962 thisblock->data.block.outer_cleanups
2963 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2964 block_stack->data.block.outer_cleanups);
2966 thisblock->data.block.outer_cleanups = 0;
2968 thisblock->data.block.label_chain = 0;
2969 thisblock->data.block.innermost_stack_block = stack_block_stack;
2970 thisblock->data.block.first_insn = note;
2971 thisblock->data.block.block_start_count = ++block_start_count;
2972 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2973 block_stack = thisblock;
2974 nesting_stack = thisblock;
2976 if (!output_bytecode)
2978 /* Make a new level for allocating stack slots. */
2983 /* Given a pointer to a BLOCK node, save a pointer to the most recently
2984 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
2988 remember_end_note (block)
2989 register tree block;
2991 BLOCK_END_NOTE (block) = last_block_end_note;
2992 last_block_end_note = NULL_RTX;
2995 /* Generate RTL code to terminate a binding contour.
2996 VARS is the chain of VAR_DECL nodes
2997 for the variables bound in this contour.
2998 MARK_ENDS is nonzero if we should put a note at the beginning
2999 and end of this binding contour.
3001 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3002 (That is true automatically if the contour has a saved stack level.) */
3005 expand_end_bindings (vars, mark_ends, dont_jump_in)
3010 register struct nesting *thisblock = block_stack;
3013 if (output_bytecode)
3015 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
3020 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3021 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
3022 && ! DECL_IN_SYSTEM_HEADER (decl))
3023 warning_with_decl (decl, "unused variable `%s'");
3025 if (thisblock->exit_label)
3027 do_pending_stack_adjust ();
3028 emit_label (thisblock->exit_label);
3031 /* If necessary, make a handler for nonlocal gotos taking
3032 place in the function calls in this block. */
3033 if (function_call_count != thisblock->data.block.function_call_count
3035 /* Make handler for outermost block
3036 if there were any nonlocal gotos to this function. */
3037 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3038 /* Make handler for inner block if it has something
3039 special to do when you jump out of it. */
3040 : (thisblock->data.block.cleanups != 0
3041 || thisblock->data.block.stack_level != 0)))
3044 rtx afterward = gen_label_rtx ();
3045 rtx handler_label = gen_label_rtx ();
3046 rtx save_receiver = gen_reg_rtx (Pmode);
3049 /* Don't let jump_optimize delete the handler. */
3050 LABEL_PRESERVE_P (handler_label) = 1;
3052 /* Record the handler address in the stack slot for that purpose,
3053 during this block, saving and restoring the outer value. */
3054 if (thisblock->next != 0)
3056 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3059 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3060 insns = get_insns ();
3062 emit_insns_before (insns, thisblock->data.block.first_insn);
3066 emit_move_insn (nonlocal_goto_handler_slot,
3067 gen_rtx (LABEL_REF, Pmode, handler_label));
3068 insns = get_insns ();
3070 emit_insns_before (insns, thisblock->data.block.first_insn);
3072 /* Jump around the handler; it runs only when specially invoked. */
3073 emit_jump (afterward);
3074 emit_label (handler_label);
3076 #ifdef HAVE_nonlocal_goto
3077 if (! HAVE_nonlocal_goto)
3079 /* First adjust our frame pointer to its actual value. It was
3080 previously set to the start of the virtual area corresponding to
3081 the stacked variables when we branched here and now needs to be
3082 adjusted to the actual hardware fp value.
3084 Assignments are to virtual registers are converted by
3085 instantiate_virtual_regs into the corresponding assignment
3086 to the underlying register (fp in this case) that makes
3087 the original assignment true.
3088 So the following insn will actually be
3089 decrementing fp by STARTING_FRAME_OFFSET. */
3090 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3092 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3093 if (fixed_regs[ARG_POINTER_REGNUM])
3095 #ifdef ELIMINABLE_REGS
3096 /* If the argument pointer can be eliminated in favor of the
3097 frame pointer, we don't need to restore it. We assume here
3098 that if such an elimination is present, it can always be used.
3099 This is the case on all known machines; if we don't make this
3100 assumption, we do unnecessary saving on many machines. */
3101 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3104 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3105 if (elim_regs[i].from == ARG_POINTER_REGNUM
3106 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3109 if (i == sizeof elim_regs / sizeof elim_regs [0])
3112 /* Now restore our arg pointer from the address at which it
3113 was saved in our stack frame.
3114 If there hasn't be space allocated for it yet, make
3116 if (arg_pointer_save_area == 0)
3117 arg_pointer_save_area
3118 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3119 emit_move_insn (virtual_incoming_args_rtx,
3120 /* We need a pseudo here, or else
3121 instantiate_virtual_regs_1 complains. */
3122 copy_to_reg (arg_pointer_save_area));
3127 /* The handler expects the desired label address in the static chain
3128 register. It tests the address and does an appropriate jump
3129 to whatever label is desired. */
3130 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3131 /* Skip any labels we shouldn't be able to jump to from here. */
3132 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3134 rtx not_this = gen_label_rtx ();
3135 rtx this = gen_label_rtx ();
3136 do_jump_if_equal (static_chain_rtx,
3137 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3139 emit_jump (not_this);
3141 expand_goto (TREE_VALUE (link));
3142 emit_label (not_this);
3144 /* If label is not recognized, abort. */
3145 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3148 emit_label (afterward);
3151 /* Don't allow jumping into a block that has cleanups or a stack level. */
3153 || thisblock->data.block.stack_level != 0
3154 || thisblock->data.block.cleanups != 0)
3156 struct label_chain *chain;
3158 /* Any labels in this block are no longer valid to go to.
3159 Mark them to cause an error message. */
3160 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3162 DECL_TOO_LATE (chain->label) = 1;
3163 /* If any goto without a fixup came to this label,
3164 that must be an error, because gotos without fixups
3165 come from outside all saved stack-levels and all cleanups. */
3166 if (TREE_ADDRESSABLE (chain->label))
3167 error_with_decl (chain->label,
3168 "label `%s' used before containing binding contour");
3172 /* Restore stack level in effect before the block
3173 (only if variable-size objects allocated). */
3174 /* Perform any cleanups associated with the block. */
3176 if (thisblock->data.block.stack_level != 0
3177 || thisblock->data.block.cleanups != 0)
3179 /* Only clean up here if this point can actually be reached. */
3180 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3182 /* Don't let cleanups affect ({...}) constructs. */
3183 int old_expr_stmts_for_value = expr_stmts_for_value;
3184 rtx old_last_expr_value = last_expr_value;
3185 tree old_last_expr_type = last_expr_type;
3186 expr_stmts_for_value = 0;
3188 /* Do the cleanups. */
3189 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3191 do_pending_stack_adjust ();
3193 expr_stmts_for_value = old_expr_stmts_for_value;
3194 last_expr_value = old_last_expr_value;
3195 last_expr_type = old_last_expr_type;
3197 /* Restore the stack level. */
3199 if (reachable && thisblock->data.block.stack_level != 0)
3201 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3202 thisblock->data.block.stack_level, NULL_RTX);
3203 if (nonlocal_goto_handler_slot != 0)
3204 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3208 /* Any gotos out of this block must also do these things.
3209 Also report any gotos with fixups that came to labels in this
3211 fixup_gotos (thisblock,
3212 thisblock->data.block.stack_level,
3213 thisblock->data.block.cleanups,
3214 thisblock->data.block.first_insn,
3218 /* Mark the beginning and end of the scope if requested.
3219 We do this now, after running cleanups on the variables
3220 just going out of scope, so they are in scope for their cleanups. */
3223 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3225 /* Get rid of the beginning-mark if we don't make an end-mark. */
3226 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3228 /* If doing stupid register allocation, make sure lives of all
3229 register variables declared here extend thru end of scope. */
3232 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3234 rtx rtl = DECL_RTL (decl);
3235 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3239 /* Restore block_stack level for containing block. */
3241 stack_block_stack = thisblock->data.block.innermost_stack_block;
3242 POPSTACK (block_stack);
3244 /* Pop the stack slot nesting and free any slots at this level. */
3249 /* End a binding contour.
3250 VARS is the chain of VAR_DECL nodes for the variables bound
3251 in this contour. MARK_ENDS is nonzer if we should put a note
3252 at the beginning and end of this binding contour.
3253 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3257 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3262 struct nesting *thisbind = nesting_stack;
3266 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3267 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3268 warning_with_decl (decl, "unused variable `%s'");
3270 if (thisbind->exit_label)
3271 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3273 /* Pop block/bindings off stack */
3274 POPSTACK (block_stack);
3277 /* Generate RTL for the automatic variable declaration DECL.
3278 (Other kinds of declarations are simply ignored if seen here.)
3279 CLEANUP is an expression to be executed at exit from this binding contour;
3280 for example, in C++, it might call the destructor for this variable.
3282 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3283 either before or after calling `expand_decl' but before compiling
3284 any subsequent expressions. This is because CLEANUP may be expanded
3285 more than once, on different branches of execution.
3286 For the same reason, CLEANUP may not contain a CALL_EXPR
3287 except as its topmost node--else `preexpand_calls' would get confused.
3289 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3290 that is not associated with any particular variable.
3292 There is no special support here for C++ constructors.
3293 They should be handled by the proper code in DECL_INITIAL. */
3299 struct nesting *thisblock = block_stack;
3302 if (output_bytecode)
3304 bc_expand_decl (decl, 0);
3308 type = TREE_TYPE (decl);
3310 /* Only automatic variables need any expansion done.
3311 Static and external variables, and external functions,
3312 will be handled by `assemble_variable' (called from finish_decl).
3313 TYPE_DECL and CONST_DECL require nothing.
3314 PARM_DECLs are handled in `assign_parms'. */
3316 if (TREE_CODE (decl) != VAR_DECL)
3318 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3321 /* Create the RTL representation for the variable. */
3323 if (type == error_mark_node)
3324 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3325 else if (DECL_SIZE (decl) == 0)
3326 /* Variable with incomplete type. */
3328 if (DECL_INITIAL (decl) == 0)
3329 /* Error message was already done; now avoid a crash. */
3330 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3332 /* An initializer is going to decide the size of this array.
3333 Until we know the size, represent its address with a reg. */
3334 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3335 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3337 else if (DECL_MODE (decl) != BLKmode
3338 /* If -ffloat-store, don't put explicit float vars
3340 && !(flag_float_store
3341 && TREE_CODE (type) == REAL_TYPE)
3342 && ! TREE_THIS_VOLATILE (decl)
3343 && ! TREE_ADDRESSABLE (decl)
3344 && (DECL_REGISTER (decl) || ! obey_regdecls))
3346 /* Automatic variable that can go in a register. */
3347 int unsignedp = TREE_UNSIGNED (type);
3348 enum machine_mode reg_mode
3349 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3351 if (TREE_CODE (type) == COMPLEX_TYPE)
3353 rtx realpart, imagpart;
3354 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3356 /* For a complex type variable, make a CONCAT of two pseudos
3357 so that the real and imaginary parts
3358 can be allocated separately. */
3359 realpart = gen_reg_rtx (partmode);
3360 REG_USERVAR_P (realpart) = 1;
3361 imagpart = gen_reg_rtx (partmode);
3362 REG_USERVAR_P (imagpart) = 1;
3363 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3367 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3368 if (TREE_CODE (type) == POINTER_TYPE)
3369 mark_reg_pointer (DECL_RTL (decl));
3370 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3373 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3375 /* Variable of fixed size that goes on the stack. */
3379 /* If we previously made RTL for this decl, it must be an array
3380 whose size was determined by the initializer.
3381 The old address was a register; set that register now
3382 to the proper address. */
3383 if (DECL_RTL (decl) != 0)
3385 if (GET_CODE (DECL_RTL (decl)) != MEM
3386 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3388 oldaddr = XEXP (DECL_RTL (decl), 0);
3392 = assign_stack_temp (DECL_MODE (decl),
3393 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3394 + BITS_PER_UNIT - 1)
3397 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3399 /* Set alignment we actually gave this decl. */
3400 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3401 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3405 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3406 if (addr != oldaddr)
3407 emit_move_insn (oldaddr, addr);
3410 /* If this is a memory ref that contains aggregate components,
3411 mark it as such for cse and loop optimize. */
3412 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3414 /* If this is in memory because of -ffloat-store,
3415 set the volatile bit, to prevent optimizations from
3416 undoing the effects. */
3417 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3418 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3422 /* Dynamic-size object: must push space on the stack. */
3426 /* Record the stack pointer on entry to block, if have
3427 not already done so. */
3428 if (thisblock->data.block.stack_level == 0)
3430 do_pending_stack_adjust ();
3431 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3432 &thisblock->data.block.stack_level,
3433 thisblock->data.block.first_insn);
3434 stack_block_stack = thisblock;
3437 /* Compute the variable's size, in bytes. */
3438 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3440 size_int (BITS_PER_UNIT)),
3441 NULL_RTX, VOIDmode, 0);
3444 /* Allocate space on the stack for the variable. */
3445 address = allocate_dynamic_stack_space (size, NULL_RTX,
3448 /* Reference the variable indirect through that rtx. */
3449 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3451 /* If this is a memory ref that contains aggregate components,
3452 mark it as such for cse and loop optimize. */
3453 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3455 /* Indicate the alignment we actually gave this variable. */
3456 #ifdef STACK_BOUNDARY
3457 DECL_ALIGN (decl) = STACK_BOUNDARY;
3459 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3463 if (TREE_THIS_VOLATILE (decl))
3464 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3465 #if 0 /* A variable is not necessarily unchanging
3466 just because it is const. RTX_UNCHANGING_P
3467 means no change in the function,
3468 not merely no change in the variable's scope.
3469 It is correct to set RTX_UNCHANGING_P if the variable's scope
3470 is the whole function. There's no convenient way to test that. */
3471 if (TREE_READONLY (decl))
3472 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3475 /* If doing stupid register allocation, make sure life of any
3476 register variable starts here, at the start of its scope. */
3479 use_variable (DECL_RTL (decl));
3483 /* Generate code for the automatic variable declaration DECL. For
3484 most variables this just means we give it a stack offset. The
3485 compiler sometimes emits cleanups without variables and we will
3486 have to deal with those too. */
3489 bc_expand_decl (decl, cleanup)
3497 /* A cleanup with no variable. */
3504 /* Only auto variables need any work. */
3505 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3508 type = TREE_TYPE (decl);
3510 if (type == error_mark_node)
3511 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3513 else if (DECL_SIZE (decl) == 0)
3515 /* Variable with incomplete type. The stack offset herein will be
3516 fixed later in expand_decl_init (). */
3517 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3519 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3521 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3525 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3528 /* Emit code to perform the initialization of a declaration DECL. */
3531 expand_decl_init (decl)
3534 int was_used = TREE_USED (decl);
3536 if (output_bytecode)
3538 bc_expand_decl_init (decl);
3542 /* If this is a CONST_DECL, we don't have to generate any code, but
3543 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3544 to be set while in the obstack containing the constant. If we don't
3545 do this, we can lose if we have functions nested three deep and the middle
3546 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3547 the innermost function is the first to expand that STRING_CST. */
3548 if (TREE_CODE (decl) == CONST_DECL)
3550 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3551 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3552 EXPAND_INITIALIZER);
3556 if (TREE_STATIC (decl))
3559 /* Compute and store the initial value now. */
3561 if (DECL_INITIAL (decl) == error_mark_node)
3563 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3564 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3565 || code == POINTER_TYPE)
3566 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3570 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3572 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3573 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3577 /* Don't let the initialization count as "using" the variable. */
3578 TREE_USED (decl) = was_used;
3580 /* Free any temporaries we made while initializing the decl. */
3581 preserve_temp_slots (NULL_RTX);
3585 /* Expand initialization for variable-sized types. Allocate array
3586 using newlocalSI and set local variable, which is a pointer to the
3590 bc_expand_variable_local_init (decl)
3593 /* Evaluate size expression and coerce to SI */
3594 bc_expand_expr (DECL_SIZE (decl));
3596 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3597 no coercion is necessary (?) */
3599 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3600 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3602 /* Emit code to allocate array */
3603 bc_emit_instruction (newlocalSI);
3605 /* Store array pointer in local variable. This is the only instance
3606 where we actually want the address of the pointer to the
3607 variable-size block, rather than the pointer itself. We avoid
3608 using expand_address() since that would cause the pointer to be
3609 pushed rather than its address. Hence the hard-coded reference;
3610 notice also that the variable is always local (no global
3611 variable-size type variables). */
3613 bc_load_localaddr (DECL_RTL (decl));
3614 bc_emit_instruction (storeP);
3618 /* Emit code to initialize a declaration. */
3621 bc_expand_decl_init (decl)
3624 int org_stack_depth;
3626 /* Statical initializers are handled elsewhere */
3628 if (TREE_STATIC (decl))
3631 /* Memory original stack depth */
3632 org_stack_depth = stack_depth;
3634 /* If the type is variable-size, we first create its space (we ASSUME
3635 it CAN'T be static). We do this regardless of whether there's an
3636 initializer assignment or not. */
3638 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3639 bc_expand_variable_local_init (decl);
3641 /* Expand initializer assignment */
3642 if (DECL_INITIAL (decl) == error_mark_node)
3644 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3646 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3647 || code == POINTER_TYPE)
3649 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3651 else if (DECL_INITIAL (decl))
3652 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3654 /* Restore stack depth */
3655 if (org_stack_depth > stack_depth)
3658 bc_adjust_stack (stack_depth - org_stack_depth);
3662 /* CLEANUP is an expression to be executed at exit from this binding contour;
3663 for example, in C++, it might call the destructor for this variable.
3665 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3666 either before or after calling `expand_decl' but before compiling
3667 any subsequent expressions. This is because CLEANUP may be expanded
3668 more than once, on different branches of execution.
3669 For the same reason, CLEANUP may not contain a CALL_EXPR
3670 except as its topmost node--else `preexpand_calls' would get confused.
3672 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3673 that is not associated with any particular variable. */
3676 expand_decl_cleanup (decl, cleanup)
3679 struct nesting *thisblock = block_stack;
3681 /* Error if we are not in any block. */
3685 /* Record the cleanup if there is one. */
3689 thisblock->data.block.cleanups
3690 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3691 /* If this block has a cleanup, it belongs in stack_block_stack. */
3692 stack_block_stack = thisblock;
3693 (*interim_eh_hook) (NULL_TREE);
3698 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3699 DECL_ELTS is the list of elements that belong to DECL's type.
3700 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3703 expand_anon_union_decl (decl, cleanup, decl_elts)
3704 tree decl, cleanup, decl_elts;
3706 struct nesting *thisblock = block_stack;
3709 expand_decl (decl, cleanup);
3710 x = DECL_RTL (decl);
3714 tree decl_elt = TREE_VALUE (decl_elts);
3715 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3716 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3718 /* Propagate the union's alignment to the elements. */
3719 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3721 /* If the element has BLKmode and the union doesn't, the union is
3722 aligned such that the element doesn't need to have BLKmode, so
3723 change the element's mode to the appropriate one for its size. */
3724 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3725 DECL_MODE (decl_elt) = mode
3726 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3729 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3730 instead create a new MEM rtx with the proper mode. */
3731 if (GET_CODE (x) == MEM)
3733 if (mode == GET_MODE (x))
3734 DECL_RTL (decl_elt) = x;
3737 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3738 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3739 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3742 else if (GET_CODE (x) == REG)
3744 if (mode == GET_MODE (x))
3745 DECL_RTL (decl_elt) = x;
3747 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3752 /* Record the cleanup if there is one. */
3755 thisblock->data.block.cleanups
3756 = temp_tree_cons (decl_elt, cleanup_elt,
3757 thisblock->data.block.cleanups);
3759 decl_elts = TREE_CHAIN (decl_elts);
3763 /* Expand a list of cleanups LIST.
3764 Elements may be expressions or may be nested lists.
3766 If DONT_DO is nonnull, then any list-element
3767 whose TREE_PURPOSE matches DONT_DO is omitted.
3768 This is sometimes used to avoid a cleanup associated with
3769 a value that is being returned out of the scope.
3771 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3772 goto and handle protection regions specially in that case.
3774 If REACHABLE, we emit code, otherwise just inform the exception handling
3775 code about this finalization. */
3778 expand_cleanups (list, dont_do, in_fixup, reachable)
3785 for (tail = list; tail; tail = TREE_CHAIN (tail))
3786 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3788 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3789 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3793 (*interim_eh_hook) (TREE_VALUE (tail));
3797 /* Cleanups may be run multiple times. For example,
3798 when exiting a binding contour, we expand the
3799 cleanups associated with that contour. When a goto
3800 within that binding contour has a target outside that
3801 contour, it will expand all cleanups from its scope to
3802 the target. Though the cleanups are expanded multiple
3803 times, the control paths are non-overlapping so the
3804 cleanups will not be executed twice. */
3805 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3812 /* Move all cleanups from the current block_stack
3813 to the containing block_stack, where they are assumed to
3814 have been created. If anything can cause a temporary to
3815 be created, but not expanded for more than one level of
3816 block_stacks, then this code will have to change. */
3821 struct nesting *block = block_stack;
3822 struct nesting *outer = block->next;
3824 outer->data.block.cleanups
3825 = chainon (block->data.block.cleanups,
3826 outer->data.block.cleanups);
3827 block->data.block.cleanups = 0;
3831 last_cleanup_this_contour ()
3833 if (block_stack == 0)
3836 return block_stack->data.block.cleanups;
3839 /* Return 1 if there are any pending cleanups at this point.
3840 If THIS_CONTOUR is nonzero, check the current contour as well.
3841 Otherwise, look only at the contours that enclose this one. */
3844 any_pending_cleanups (this_contour)
3847 struct nesting *block;
3849 if (block_stack == 0)
3852 if (this_contour && block_stack->data.block.cleanups != NULL)
3854 if (block_stack->data.block.cleanups == 0
3855 && (block_stack->data.block.outer_cleanups == 0
3857 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3862 for (block = block_stack->next; block; block = block->next)
3863 if (block->data.block.cleanups != 0)
3869 /* Enter a case (Pascal) or switch (C) statement.
3870 Push a block onto case_stack and nesting_stack
3871 to accumulate the case-labels that are seen
3872 and to record the labels generated for the statement.
3874 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3875 Otherwise, this construct is transparent for `exit_something'.
3877 EXPR is the index-expression to be dispatched on.
3878 TYPE is its nominal type. We could simply convert EXPR to this type,
3879 but instead we take short cuts. */
3882 expand_start_case (exit_flag, expr, type, printname)
3888 register struct nesting *thiscase = ALLOC_NESTING ();
3890 /* Make an entry on case_stack for the case we are entering. */
3892 thiscase->next = case_stack;
3893 thiscase->all = nesting_stack;
3894 thiscase->depth = ++nesting_depth;
3895 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3896 thiscase->data.case_stmt.case_list = 0;
3897 thiscase->data.case_stmt.index_expr = expr;
3898 thiscase->data.case_stmt.nominal_type = type;
3899 thiscase->data.case_stmt.default_label = 0;
3900 thiscase->data.case_stmt.num_ranges = 0;
3901 thiscase->data.case_stmt.printname = printname;
3902 thiscase->data.case_stmt.seenlabel = 0;
3903 case_stack = thiscase;
3904 nesting_stack = thiscase;
3906 if (output_bytecode)
3908 bc_expand_start_case (thiscase, expr, type, printname);
3912 do_pending_stack_adjust ();
3914 /* Make sure case_stmt.start points to something that won't
3915 need any transformation before expand_end_case. */
3916 if (GET_CODE (get_last_insn ()) != NOTE)
3917 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3919 thiscase->data.case_stmt.start = get_last_insn ();
3923 /* Enter a case statement. It is assumed that the caller has pushed
3924 the current context onto the case stack. */
3927 bc_expand_start_case (thiscase, expr, type, printname)
3928 struct nesting *thiscase;
3933 bc_expand_expr (expr);
3934 bc_expand_conversion (TREE_TYPE (expr), type);
3936 /* For cases, the skip is a place we jump to that's emitted after
3937 the size of the jump table is known. */
3939 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3940 bc_emit_bytecode (jump);
3941 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3943 #ifdef DEBUG_PRINT_CODE
3944 fputc ('\n', stderr);
3949 /* Start a "dummy case statement" within which case labels are invalid
3950 and are not connected to any larger real case statement.
3951 This can be used if you don't want to let a case statement jump
3952 into the middle of certain kinds of constructs. */
3955 expand_start_case_dummy ()
3957 register struct nesting *thiscase = ALLOC_NESTING ();
3959 /* Make an entry on case_stack for the dummy. */
3961 thiscase->next = case_stack;
3962 thiscase->all = nesting_stack;
3963 thiscase->depth = ++nesting_depth;
3964 thiscase->exit_label = 0;
3965 thiscase->data.case_stmt.case_list = 0;
3966 thiscase->data.case_stmt.start = 0;
3967 thiscase->data.case_stmt.nominal_type = 0;
3968 thiscase->data.case_stmt.default_label = 0;
3969 thiscase->data.case_stmt.num_ranges = 0;
3970 case_stack = thiscase;
3971 nesting_stack = thiscase;
3974 /* End a dummy case statement. */
3977 expand_end_case_dummy ()
3979 POPSTACK (case_stack);
3982 /* Return the data type of the index-expression
3983 of the innermost case statement, or null if none. */
3986 case_index_expr_type ()
3989 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
3993 /* Accumulate one case or default label inside a case or switch statement.
3994 VALUE is the value of the case (a null pointer, for a default label).
3995 The function CONVERTER, when applied to arguments T and V,
3996 converts the value V to the type T.
3998 If not currently inside a case or switch statement, return 1 and do
3999 nothing. The caller will print a language-specific error message.
4000 If VALUE is a duplicate or overlaps, return 2 and do nothing
4001 except store the (first) duplicate node in *DUPLICATE.
4002 If VALUE is out of range, return 3 and do nothing.
4003 If we are jumping into the scope of a cleaup or var-sized array, return 5.
4004 Return 0 on success.
4006 Extended to handle range statements. */
4009 pushcase (value, converter, label, duplicate)
4010 register tree value;
4011 tree (*converter) PROTO((tree, tree));
4012 register tree label;
4015 register struct case_node **l;
4016 register struct case_node *n;
4020 if (output_bytecode)
4021 return bc_pushcase (value, label);
4023 /* Fail if not inside a real case statement. */
4024 if (! (case_stack && case_stack->data.case_stmt.start))
4027 if (stack_block_stack
4028 && stack_block_stack->depth > case_stack->depth)
4031 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4032 nominal_type = case_stack->data.case_stmt.nominal_type;
4034 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4035 if (index_type == error_mark_node)
4038 /* Convert VALUE to the type in which the comparisons are nominally done. */
4040 value = (*converter) (nominal_type, value);
4042 /* If this is the first label, warn if any insns have been emitted. */
4043 if (case_stack->data.case_stmt.seenlabel == 0)
4046 for (insn = case_stack->data.case_stmt.start;
4048 insn = NEXT_INSN (insn))
4050 if (GET_CODE (insn) == CODE_LABEL)
4052 if (GET_CODE (insn) != NOTE
4053 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4055 warning ("unreachable code at beginning of %s",
4056 case_stack->data.case_stmt.printname);
4061 case_stack->data.case_stmt.seenlabel = 1;
4063 /* Fail if this value is out of range for the actual type of the index
4064 (which may be narrower than NOMINAL_TYPE). */
4065 if (value != 0 && ! int_fits_type_p (value, index_type))
4068 /* Fail if this is a duplicate or overlaps another entry. */
4071 if (case_stack->data.case_stmt.default_label != 0)
4073 *duplicate = case_stack->data.case_stmt.default_label;
4076 case_stack->data.case_stmt.default_label = label;
4080 /* Find the elt in the chain before which to insert the new value,
4081 to keep the chain sorted in increasing order.
4082 But report an error if this element is a duplicate. */
4083 for (l = &case_stack->data.case_stmt.case_list;
4084 /* Keep going past elements distinctly less than VALUE. */
4085 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4090 /* Element we will insert before must be distinctly greater;
4091 overlap means error. */
4092 if (! tree_int_cst_lt (value, (*l)->low))
4094 *duplicate = (*l)->code_label;
4099 /* Add this label to the chain, and succeed.
4100 Copy VALUE so it is on temporary rather than momentary
4101 obstack and will thus survive till the end of the case statement. */
4102 n = (struct case_node *) oballoc (sizeof (struct case_node));
4105 n->high = n->low = copy_node (value);
4106 n->code_label = label;
4110 expand_label (label);
4114 /* Like pushcase but this case applies to all values
4115 between VALUE1 and VALUE2 (inclusive).
4116 The return value is the same as that of pushcase
4117 but there is one additional error code:
4118 4 means the specified range was empty. */
4121 pushcase_range (value1, value2, converter, label, duplicate)
4122 register tree value1, value2;
4123 tree (*converter) PROTO((tree, tree));
4124 register tree label;
4127 register struct case_node **l;
4128 register struct case_node *n;
4132 /* Fail if not inside a real case statement. */
4133 if (! (case_stack && case_stack->data.case_stmt.start))
4136 if (stack_block_stack
4137 && stack_block_stack->depth > case_stack->depth)
4140 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4141 nominal_type = case_stack->data.case_stmt.nominal_type;
4143 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4144 if (index_type == error_mark_node)
4147 /* If this is the first label, warn if any insns have been emitted. */
4148 if (case_stack->data.case_stmt.seenlabel == 0)
4151 for (insn = case_stack->data.case_stmt.start;
4153 insn = NEXT_INSN (insn))
4155 if (GET_CODE (insn) == CODE_LABEL)
4157 if (GET_CODE (insn) != NOTE
4158 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4160 warning ("unreachable code at beginning of %s",
4161 case_stack->data.case_stmt.printname);
4166 case_stack->data.case_stmt.seenlabel = 1;
4168 /* Convert VALUEs to type in which the comparisons are nominally done. */
4169 if (value1 == 0) /* Negative infinity. */
4170 value1 = TYPE_MIN_VALUE(index_type);
4171 value1 = (*converter) (nominal_type, value1);
4173 if (value2 == 0) /* Positive infinity. */
4174 value2 = TYPE_MAX_VALUE(index_type);
4175 value2 = (*converter) (nominal_type, value2);
4177 /* Fail if these values are out of range. */
4178 if (! int_fits_type_p (value1, index_type))
4181 if (! int_fits_type_p (value2, index_type))
4184 /* Fail if the range is empty. */
4185 if (tree_int_cst_lt (value2, value1))
4188 /* If the bounds are equal, turn this into the one-value case. */
4189 if (tree_int_cst_equal (value1, value2))
4190 return pushcase (value1, converter, label, duplicate);
4192 /* Find the elt in the chain before which to insert the new value,
4193 to keep the chain sorted in increasing order.
4194 But report an error if this element is a duplicate. */
4195 for (l = &case_stack->data.case_stmt.case_list;
4196 /* Keep going past elements distinctly less than this range. */
4197 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4202 /* Element we will insert before must be distinctly greater;
4203 overlap means error. */
4204 if (! tree_int_cst_lt (value2, (*l)->low))
4206 *duplicate = (*l)->code_label;
4211 /* Add this label to the chain, and succeed.
4212 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4213 obstack and will thus survive till the end of the case statement. */
4215 n = (struct case_node *) oballoc (sizeof (struct case_node));
4218 n->low = copy_node (value1);
4219 n->high = copy_node (value2);
4220 n->code_label = label;
4223 expand_label (label);
4225 case_stack->data.case_stmt.num_ranges++;
4231 /* Accumulate one case or default label; VALUE is the value of the
4232 case, or nil for a default label. If not currently inside a case,
4233 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4234 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4235 Return 0 on success. This function is a leftover from the earlier
4236 bytecode compiler, which was based on gcc 1.37. It should be
4237 merged into pushcase. */
4240 bc_pushcase (value, label)
4244 struct nesting *thiscase = case_stack;
4245 struct case_node *case_label, *new_label;
4250 /* Fail if duplicate, overlap, or out of type range. */
4253 value = convert (thiscase->data.case_stmt.nominal_type, value);
4254 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4257 for (case_label = thiscase->data.case_stmt.case_list;
4258 case_label->left; case_label = case_label->left)
4259 if (! tree_int_cst_lt (case_label->left->high, value))
4262 if (case_label != thiscase->data.case_stmt.case_list
4263 && ! tree_int_cst_lt (case_label->high, value)
4264 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4267 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4268 new_label->low = new_label->high = copy_node (value);
4269 new_label->code_label = label;
4270 new_label->left = case_label->left;
4272 case_label->left = new_label;
4273 thiscase->data.case_stmt.num_ranges++;
4277 if (thiscase->data.case_stmt.default_label)
4279 thiscase->data.case_stmt.default_label = label;
4282 expand_label (label);
4286 /* Returns the number of possible values of TYPE.
4287 Returns -1 if the number is unknown or variable.
4288 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4289 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4290 do not increase monotonically (there may be duplicates);
4291 to 1 if the values increase monotonically, but not always by 1;
4292 otherwise sets it to 0. */
4295 all_cases_count (type, spareness)
4299 HOST_WIDE_INT count, count_high = 0;
4302 switch (TREE_CODE (type))
4309 count = 1 << BITS_PER_UNIT;
4313 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4314 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4319 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4320 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4321 but with overflow checking. */
4322 tree mint = TYPE_MIN_VALUE (type);
4323 tree maxt = TYPE_MAX_VALUE (type);
4324 HOST_WIDE_INT lo, hi;
4325 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4327 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4329 add_double (lo, hi, 1, 0, &lo, &hi);
4330 if (hi != 0 || lo < 0)
4337 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4339 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4340 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4341 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4342 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4346 if (*spareness == 1)
4348 tree prev = TREE_VALUE (TYPE_VALUES (type));
4349 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4351 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4356 prev = TREE_VALUE (t);
4365 #define BITARRAY_TEST(ARRAY, INDEX) \
4366 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4367 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4368 #define BITARRAY_SET(ARRAY, INDEX) \
4369 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4370 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4372 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4373 with the case values we have seen, assuming the case expression
4375 SPARSENESS is as determined by all_cases_count.
4377 The time needed is proportional to COUNT, unless
4378 SPARSENESS is 2, in which case quadratic time is needed. */
4381 mark_seen_cases (type, cases_seen, count, sparseness)
4383 unsigned char *cases_seen;
4389 tree next_node_to_try = NULL_TREE;
4390 long next_node_offset = 0;
4392 register struct case_node *n;
4393 tree val = make_node (INTEGER_CST);
4394 TREE_TYPE (val) = type;
4395 for (n = case_stack->data.case_stmt.case_list; n;
4398 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4399 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4400 while ( ! tree_int_cst_lt (n->high, val))
4402 /* Calculate (into xlo) the "offset" of the integer (val).
4403 The element with lowest value has offset 0, the next smallest
4404 element has offset 1, etc. */
4406 HOST_WIDE_INT xlo, xhi;
4408 if (sparseness == 2)
4410 /* This less efficient loop is only needed to handle
4411 duplicate case values (multiple enum constants
4412 with the same value). */
4413 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4414 t = TREE_CHAIN (t), xlo++)
4416 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4417 BITARRAY_SET (cases_seen, xlo);
4422 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4424 /* The TYPE_VALUES will be in increasing order, so
4425 starting searching where we last ended. */
4426 t = next_node_to_try;
4427 xlo = next_node_offset;
4433 t = TYPE_VALUES (type);
4436 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4438 next_node_to_try = TREE_CHAIN (t);
4439 next_node_offset = xlo + 1;
4444 if (t == next_node_to_try)
4450 t = TYPE_MIN_VALUE (type);
4452 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4456 add_double (xlo, xhi,
4457 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4461 if (xhi == 0 && xlo >= 0 && xlo < count)
4462 BITARRAY_SET (cases_seen, xlo);
4464 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4466 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4471 /* Called when the index of a switch statement is an enumerated type
4472 and there is no default label.
4474 Checks that all enumeration literals are covered by the case
4475 expressions of a switch. Also, warn if there are any extra
4476 switch cases that are *not* elements of the enumerated type.
4478 If all enumeration literals were covered by the case expressions,
4479 turn one of the expressions into the default expression since it should
4480 not be possible to fall through such a switch. */
4483 check_for_full_enumeration_handling (type)
4486 register struct case_node *n;
4487 register struct case_node **l;
4488 register tree chain;
4491 /* True iff the selector type is a numbered set mode. */
4494 /* The number of possible selector values. */
4497 /* For each possible selector value. a one iff it has been matched
4498 by a case value alternative. */
4499 unsigned char *cases_seen;
4501 /* The allocated size of cases_seen, in chars. */
4505 if (output_bytecode)
4507 bc_check_for_full_enumeration_handling (type);
4514 size = all_cases_count (type, &sparseness);
4515 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4517 if (size > 0 && size < 600000
4518 /* We deliberately use malloc here - not xmalloc. */
4519 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4522 tree v = TYPE_VALUES (type);
4523 bzero (cases_seen, bytes_needed);
4525 /* The time complexity of this code is normally O(N), where
4526 N being the number of members in the enumerated type.
4527 However, if type is a ENUMERAL_TYPE whose values do not
4528 increase monotonically, quadratic time may be needed. */
4530 mark_seen_cases (type, cases_seen, size, sparseness);
4532 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4534 if (BITARRAY_TEST(cases_seen, i) == 0)
4535 warning ("enumeration value `%s' not handled in switch",
4536 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4542 /* Now we go the other way around; we warn if there are case
4543 expressions that don't correspond to enumerators. This can
4544 occur since C and C++ don't enforce type-checking of
4545 assignments to enumeration variables. */
4548 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4550 for (chain = TYPE_VALUES (type);
4551 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4552 chain = TREE_CHAIN (chain))
4557 if (TYPE_NAME (type) == 0)
4558 warning ("case value `%d' not in enumerated type",
4559 TREE_INT_CST_LOW (n->low));
4561 warning ("case value `%d' not in enumerated type `%s'",
4562 TREE_INT_CST_LOW (n->low),
4563 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4566 : DECL_NAME (TYPE_NAME (type))));
4568 if (!tree_int_cst_equal (n->low, n->high))
4570 for (chain = TYPE_VALUES (type);
4571 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4572 chain = TREE_CHAIN (chain))
4577 if (TYPE_NAME (type) == 0)
4578 warning ("case value `%d' not in enumerated type",
4579 TREE_INT_CST_LOW (n->high));
4581 warning ("case value `%d' not in enumerated type `%s'",
4582 TREE_INT_CST_LOW (n->high),
4583 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4586 : DECL_NAME (TYPE_NAME (type))));
4592 /* ??? This optimization is disabled because it causes valid programs to
4593 fail. ANSI C does not guarantee that an expression with enum type
4594 will have a value that is the same as one of the enumeration literals. */
4596 /* If all values were found as case labels, make one of them the default
4597 label. Thus, this switch will never fall through. We arbitrarily pick
4598 the last one to make the default since this is likely the most
4599 efficient choice. */
4603 for (l = &case_stack->data.case_stmt.case_list;
4608 case_stack->data.case_stmt.default_label = (*l)->code_label;
4615 /* Check that all enumeration literals are covered by the case
4616 expressions of a switch. Also warn if there are any cases
4617 that are not elements of the enumerated type. */
4620 bc_check_for_full_enumeration_handling (type)
4623 struct nesting *thiscase = case_stack;
4624 struct case_node *c;
4627 /* Check for enums not handled. */
4628 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4630 for (c = thiscase->data.case_stmt.case_list->left;
4631 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4634 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4635 warning ("enumerated value `%s' not handled in switch",
4636 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4639 /* Check for cases not in the enumeration. */
4640 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4642 for (e = TYPE_VALUES (type);
4643 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4647 warning ("case value `%d' not in enumerated type `%s'",
4648 TREE_INT_CST_LOW (c->low),
4649 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4651 : DECL_NAME (TYPE_NAME (type))));
4655 /* Terminate a case (Pascal) or switch (C) statement
4656 in which ORIG_INDEX is the expression to be tested.
4657 Generate the code to test it and jump to the right place. */
4660 expand_end_case (orig_index)
4663 tree minval, maxval, range, orig_minval;
4664 rtx default_label = 0;
4665 register struct case_node *n;
4673 register struct nesting *thiscase = case_stack;
4674 tree index_expr, index_type;
4677 if (output_bytecode)
4679 bc_expand_end_case (orig_index);
4683 table_label = gen_label_rtx ();
4684 index_expr = thiscase->data.case_stmt.index_expr;
4685 index_type = TREE_TYPE (index_expr);
4686 unsignedp = TREE_UNSIGNED (index_type);
4688 do_pending_stack_adjust ();
4690 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4691 if (index_type != error_mark_node)
4693 /* If switch expression was an enumerated type, check that all
4694 enumeration literals are covered by the cases.
4695 No sense trying this if there's a default case, however. */
4697 if (!thiscase->data.case_stmt.default_label
4698 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4699 && TREE_CODE (index_expr) != INTEGER_CST)
4700 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4702 /* If this is the first label, warn if any insns have been emitted. */
4703 if (thiscase->data.case_stmt.seenlabel == 0)
4706 for (insn = get_last_insn ();
4707 insn != case_stack->data.case_stmt.start;
4708 insn = PREV_INSN (insn))
4709 if (GET_CODE (insn) != NOTE
4710 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4712 warning ("unreachable code at beginning of %s",
4713 case_stack->data.case_stmt.printname);
4718 /* If we don't have a default-label, create one here,
4719 after the body of the switch. */
4720 if (thiscase->data.case_stmt.default_label == 0)
4722 thiscase->data.case_stmt.default_label
4723 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4724 expand_label (thiscase->data.case_stmt.default_label);
4726 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4728 before_case = get_last_insn ();
4730 /* Simplify the case-list before we count it. */
4731 group_case_nodes (thiscase->data.case_stmt.case_list);
4733 /* Get upper and lower bounds of case values.
4734 Also convert all the case values to the index expr's data type. */
4737 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4739 /* Check low and high label values are integers. */
4740 if (TREE_CODE (n->low) != INTEGER_CST)
4742 if (TREE_CODE (n->high) != INTEGER_CST)
4745 n->low = convert (index_type, n->low);
4746 n->high = convert (index_type, n->high);
4748 /* Count the elements and track the largest and smallest
4749 of them (treating them as signed even if they are not). */
4757 if (INT_CST_LT (n->low, minval))
4759 if (INT_CST_LT (maxval, n->high))
4762 /* A range counts double, since it requires two compares. */
4763 if (! tree_int_cst_equal (n->low, n->high))
4767 orig_minval = minval;
4769 /* Compute span of values. */
4771 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4775 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4777 emit_jump (default_label);
4780 /* If range of values is much bigger than number of values,
4781 make a sequence of conditional branches instead of a dispatch.
4782 If the switch-index is a constant, do it this way
4783 because we can optimize it. */
4785 #ifndef CASE_VALUES_THRESHOLD
4787 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4789 /* If machine does not have a case insn that compares the
4790 bounds, this means extra overhead for dispatch tables
4791 which raises the threshold for using them. */
4792 #define CASE_VALUES_THRESHOLD 5
4793 #endif /* HAVE_casesi */
4794 #endif /* CASE_VALUES_THRESHOLD */
4796 else if (TREE_INT_CST_HIGH (range) != 0
4797 || count < CASE_VALUES_THRESHOLD
4798 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4800 || TREE_CODE (index_expr) == INTEGER_CST
4801 /* These will reduce to a constant. */
4802 || (TREE_CODE (index_expr) == CALL_EXPR
4803 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4804 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4805 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4806 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4807 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4809 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4811 /* If the index is a short or char that we do not have
4812 an insn to handle comparisons directly, convert it to
4813 a full integer now, rather than letting each comparison
4814 generate the conversion. */
4816 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4817 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4818 == CODE_FOR_nothing))
4820 enum machine_mode wider_mode;
4821 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4822 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4823 if (cmp_optab->handlers[(int) wider_mode].insn_code
4824 != CODE_FOR_nothing)
4826 index = convert_to_mode (wider_mode, index, unsignedp);
4832 do_pending_stack_adjust ();
4834 index = protect_from_queue (index, 0);
4835 if (GET_CODE (index) == MEM)
4836 index = copy_to_reg (index);
4837 if (GET_CODE (index) == CONST_INT
4838 || TREE_CODE (index_expr) == INTEGER_CST)
4840 /* Make a tree node with the proper constant value
4841 if we don't already have one. */
4842 if (TREE_CODE (index_expr) != INTEGER_CST)
4845 = build_int_2 (INTVAL (index),
4846 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4847 index_expr = convert (index_type, index_expr);
4850 /* For constant index expressions we need only
4851 issue a unconditional branch to the appropriate
4852 target code. The job of removing any unreachable
4853 code is left to the optimisation phase if the
4854 "-O" option is specified. */
4855 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4856 if (! tree_int_cst_lt (index_expr, n->low)
4857 && ! tree_int_cst_lt (n->high, index_expr))
4861 emit_jump (label_rtx (n->code_label));
4863 emit_jump (default_label);
4867 /* If the index expression is not constant we generate
4868 a binary decision tree to select the appropriate
4869 target code. This is done as follows:
4871 The list of cases is rearranged into a binary tree,
4872 nearly optimal assuming equal probability for each case.
4874 The tree is transformed into RTL, eliminating
4875 redundant test conditions at the same time.
4877 If program flow could reach the end of the
4878 decision tree an unconditional jump to the
4879 default code is emitted. */
4882 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4883 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4884 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4886 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4887 default_label, index_type);
4888 emit_jump_if_reachable (default_label);
4897 enum machine_mode index_mode = SImode;
4898 int index_bits = GET_MODE_BITSIZE (index_mode);
4900 enum machine_mode op_mode;
4902 /* Convert the index to SImode. */
4903 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4904 > GET_MODE_BITSIZE (index_mode))
4906 enum machine_mode omode = TYPE_MODE (index_type);
4907 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4909 /* We must handle the endpoints in the original mode. */
4910 index_expr = build (MINUS_EXPR, index_type,
4911 index_expr, minval);
4912 minval = integer_zero_node;
4913 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4914 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4915 emit_jump_insn (gen_bltu (default_label));
4916 /* Now we can safely truncate. */
4917 index = convert_to_mode (index_mode, index, 0);
4921 if (TYPE_MODE (index_type) != index_mode)
4923 index_expr = convert (type_for_size (index_bits, 0),
4925 index_type = TREE_TYPE (index_expr);
4928 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4931 index = protect_from_queue (index, 0);
4932 do_pending_stack_adjust ();
4934 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4935 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4937 index = copy_to_mode_reg (op_mode, index);
4939 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4941 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4942 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4944 op1 = copy_to_mode_reg (op_mode, op1);
4946 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4948 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4949 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4951 op2 = copy_to_mode_reg (op_mode, op2);
4953 emit_jump_insn (gen_casesi (index, op1, op2,
4954 table_label, default_label));
4958 #ifdef HAVE_tablejump
4959 if (! win && HAVE_tablejump)
4961 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4962 fold (build (MINUS_EXPR, index_type,
4963 index_expr, minval)));
4964 index_type = TREE_TYPE (index_expr);
4965 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4967 index = protect_from_queue (index, 0);
4968 do_pending_stack_adjust ();
4970 do_tablejump (index, TYPE_MODE (index_type),
4971 expand_expr (range, NULL_RTX, VOIDmode, 0),
4972 table_label, default_label);
4979 /* Get table of labels to jump to, in order of case index. */
4981 ncases = TREE_INT_CST_LOW (range) + 1;
4982 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
4983 bzero ((char *) labelvec, ncases * sizeof (rtx));
4985 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4987 register HOST_WIDE_INT i
4988 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
4993 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
4994 if (i + TREE_INT_CST_LOW (orig_minval)
4995 == TREE_INT_CST_LOW (n->high))
5001 /* Fill in the gaps with the default. */
5002 for (i = 0; i < ncases; i++)
5003 if (labelvec[i] == 0)
5004 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
5006 /* Output the table */
5007 emit_label (table_label);
5009 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
5010 were an expression, instead of an #ifdef/#ifndef. */
5012 #ifdef CASE_VECTOR_PC_RELATIVE
5016 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
5017 gen_rtx (LABEL_REF, Pmode, table_label),
5018 gen_rtvec_v (ncases, labelvec)));
5020 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
5021 gen_rtvec_v (ncases, labelvec)));
5023 /* If the case insn drops through the table,
5024 after the table we must jump to the default-label.
5025 Otherwise record no drop-through after the table. */
5026 #ifdef CASE_DROPS_THROUGH
5027 emit_jump (default_label);
5033 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5034 reorder_insns (before_case, get_last_insn (),
5035 thiscase->data.case_stmt.start);
5038 if (thiscase->exit_label)
5039 emit_label (thiscase->exit_label);
5041 POPSTACK (case_stack);
5047 /* Terminate a case statement. EXPR is the original index
5051 bc_expand_end_case (expr)
5054 struct nesting *thiscase = case_stack;
5055 enum bytecode_opcode opcode;
5056 struct bc_label *jump_label;
5057 struct case_node *c;
5059 bc_emit_bytecode (jump);
5060 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5062 #ifdef DEBUG_PRINT_CODE
5063 fputc ('\n', stderr);
5066 /* Now that the size of the jump table is known, emit the actual
5067 indexed jump instruction. */
5068 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5070 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5071 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5072 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5074 bc_emit_bytecode (opcode);
5076 /* Now emit the case instructions literal arguments, in order.
5077 In addition to the value on the stack, it uses:
5078 1. The address of the jump table.
5079 2. The size of the jump table.
5080 3. The default label. */
5082 jump_label = bc_get_bytecode_label ();
5083 bc_emit_bytecode_labelref (jump_label);
5084 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5085 sizeof thiscase->data.case_stmt.num_ranges);
5087 if (thiscase->data.case_stmt.default_label)
5088 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5090 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5092 /* Output the jump table. */
5094 bc_align_bytecode (3 /* PTR_ALIGN */);
5095 bc_emit_bytecode_labeldef (jump_label);
5097 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5098 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5100 opcode = TREE_INT_CST_LOW (c->low);
5101 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5103 opcode = TREE_INT_CST_LOW (c->high);
5104 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5106 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5109 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5110 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5112 bc_emit_bytecode_DI_const (c->low);
5113 bc_emit_bytecode_DI_const (c->high);
5115 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5122 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5124 /* Possibly issue enumeration warnings. */
5126 if (!thiscase->data.case_stmt.default_label
5127 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5128 && TREE_CODE (expr) != INTEGER_CST
5130 check_for_full_enumeration_handling (TREE_TYPE (expr));
5133 #ifdef DEBUG_PRINT_CODE
5134 fputc ('\n', stderr);
5137 POPSTACK (case_stack);
5141 /* Return unique bytecode ID. */
5146 static int bc_uid = 0;
5151 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5154 do_jump_if_equal (op1, op2, label, unsignedp)
5155 rtx op1, op2, label;
5158 if (GET_CODE (op1) == CONST_INT
5159 && GET_CODE (op2) == CONST_INT)
5161 if (INTVAL (op1) == INTVAL (op2))
5166 enum machine_mode mode = GET_MODE (op1);
5167 if (mode == VOIDmode)
5168 mode = GET_MODE (op2);
5169 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5170 emit_jump_insn (gen_beq (label));
5174 /* Not all case values are encountered equally. This function
5175 uses a heuristic to weight case labels, in cases where that
5176 looks like a reasonable thing to do.
5178 Right now, all we try to guess is text, and we establish the
5181 chars above space: 16
5190 If we find any cases in the switch that are not either -1 or in the range
5191 of valid ASCII characters, or are control characters other than those
5192 commonly used with "\", don't treat this switch scanning text.
5194 Return 1 if these nodes are suitable for cost estimation, otherwise
5198 estimate_case_costs (node)
5201 tree min_ascii = build_int_2 (-1, -1);
5202 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5206 /* If we haven't already made the cost table, make it now. Note that the
5207 lower bound of the table is -1, not zero. */
5209 if (cost_table == NULL)
5211 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5212 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5214 for (i = 0; i < 128; i++)
5218 else if (ispunct (i))
5220 else if (iscntrl (i))
5224 cost_table[' '] = 8;
5225 cost_table['\t'] = 4;
5226 cost_table['\0'] = 4;
5227 cost_table['\n'] = 2;
5228 cost_table['\f'] = 1;
5229 cost_table['\v'] = 1;
5230 cost_table['\b'] = 1;
5233 /* See if all the case expressions look like text. It is text if the
5234 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5235 as signed arithmetic since we don't want to ever access cost_table with a
5236 value less than -1. Also check that none of the constants in a range
5237 are strange control characters. */
5239 for (n = node; n; n = n->right)
5241 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5244 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5245 if (cost_table[i] < 0)
5249 /* All interesting values are within the range of interesting
5250 ASCII characters. */
5254 /* Scan an ordered list of case nodes
5255 combining those with consecutive values or ranges.
5257 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5260 group_case_nodes (head)
5263 case_node_ptr node = head;
5267 rtx lb = next_real_insn (label_rtx (node->code_label));
5268 case_node_ptr np = node;
5270 /* Try to group the successors of NODE with NODE. */
5271 while (((np = np->right) != 0)
5272 /* Do they jump to the same place? */
5273 && next_real_insn (label_rtx (np->code_label)) == lb
5274 /* Are their ranges consecutive? */
5275 && tree_int_cst_equal (np->low,
5276 fold (build (PLUS_EXPR,
5277 TREE_TYPE (node->high),
5280 /* An overflow is not consecutive. */
5281 && tree_int_cst_lt (node->high,
5282 fold (build (PLUS_EXPR,
5283 TREE_TYPE (node->high),
5285 integer_one_node))))
5287 node->high = np->high;
5289 /* NP is the first node after NODE which can't be grouped with it.
5290 Delete the nodes in between, and move on to that node. */
5296 /* Take an ordered list of case nodes
5297 and transform them into a near optimal binary tree,
5298 on the assumption that any target code selection value is as
5299 likely as any other.
5301 The transformation is performed by splitting the ordered
5302 list into two equal sections plus a pivot. The parts are
5303 then attached to the pivot as left and right branches. Each
5304 branch is is then transformed recursively. */
5307 balance_case_nodes (head, parent)
5308 case_node_ptr *head;
5309 case_node_ptr parent;
5311 register case_node_ptr np;
5319 register case_node_ptr *npp;
5322 /* Count the number of entries on branch. Also count the ranges. */
5326 if (!tree_int_cst_equal (np->low, np->high))
5330 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5334 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5342 /* Split this list if it is long enough for that to help. */
5347 /* Find the place in the list that bisects the list's total cost,
5348 Here I gets half the total cost. */
5353 /* Skip nodes while their cost does not reach that amount. */
5354 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5355 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5356 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5359 npp = &(*npp)->right;
5364 /* Leave this branch lopsided, but optimize left-hand
5365 side and fill in `parent' fields for right-hand side. */
5367 np->parent = parent;
5368 balance_case_nodes (&np->left, np);
5369 for (; np->right; np = np->right)
5370 np->right->parent = np;
5374 /* If there are just three nodes, split at the middle one. */
5376 npp = &(*npp)->right;
5379 /* Find the place in the list that bisects the list's total cost,
5380 where ranges count as 2.
5381 Here I gets half the total cost. */
5382 i = (i + ranges + 1) / 2;
5385 /* Skip nodes while their cost does not reach that amount. */
5386 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5391 npp = &(*npp)->right;
5396 np->parent = parent;
5399 /* Optimize each of the two split parts. */
5400 balance_case_nodes (&np->left, np);
5401 balance_case_nodes (&np->right, np);
5405 /* Else leave this branch as one level,
5406 but fill in `parent' fields. */
5408 np->parent = parent;
5409 for (; np->right; np = np->right)
5410 np->right->parent = np;
5415 /* Search the parent sections of the case node tree
5416 to see if a test for the lower bound of NODE would be redundant.
5417 INDEX_TYPE is the type of the index expression.
5419 The instructions to generate the case decision tree are
5420 output in the same order as nodes are processed so it is
5421 known that if a parent node checks the range of the current
5422 node minus one that the current node is bounded at its lower
5423 span. Thus the test would be redundant. */
5426 node_has_low_bound (node, index_type)
5431 case_node_ptr pnode;
5433 /* If the lower bound of this node is the lowest value in the index type,
5434 we need not test it. */
5436 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5439 /* If this node has a left branch, the value at the left must be less
5440 than that at this node, so it cannot be bounded at the bottom and
5441 we need not bother testing any further. */
5446 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5447 node->low, integer_one_node));
5449 /* If the subtraction above overflowed, we can't verify anything.
5450 Otherwise, look for a parent that tests our value - 1. */
5452 if (! tree_int_cst_lt (low_minus_one, node->low))
5455 for (pnode = node->parent; pnode; pnode = pnode->parent)
5456 if (tree_int_cst_equal (low_minus_one, pnode->high))
5462 /* Search the parent sections of the case node tree
5463 to see if a test for the upper bound of NODE would be redundant.
5464 INDEX_TYPE is the type of the index expression.
5466 The instructions to generate the case decision tree are
5467 output in the same order as nodes are processed so it is
5468 known that if a parent node checks the range of the current
5469 node plus one that the current node is bounded at its upper
5470 span. Thus the test would be redundant. */
5473 node_has_high_bound (node, index_type)
5478 case_node_ptr pnode;
5480 /* If the upper bound of this node is the highest value in the type
5481 of the index expression, we need not test against it. */
5483 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5486 /* If this node has a right branch, the value at the right must be greater
5487 than that at this node, so it cannot be bounded at the top and
5488 we need not bother testing any further. */
5493 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5494 node->high, integer_one_node));
5496 /* If the addition above overflowed, we can't verify anything.
5497 Otherwise, look for a parent that tests our value + 1. */
5499 if (! tree_int_cst_lt (node->high, high_plus_one))
5502 for (pnode = node->parent; pnode; pnode = pnode->parent)
5503 if (tree_int_cst_equal (high_plus_one, pnode->low))
5509 /* Search the parent sections of the
5510 case node tree to see if both tests for the upper and lower
5511 bounds of NODE would be redundant. */
5514 node_is_bounded (node, index_type)
5518 return (node_has_low_bound (node, index_type)
5519 && node_has_high_bound (node, index_type));
5522 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5525 emit_jump_if_reachable (label)
5528 if (GET_CODE (get_last_insn ()) != BARRIER)
5532 /* Emit step-by-step code to select a case for the value of INDEX.
5533 The thus generated decision tree follows the form of the
5534 case-node binary tree NODE, whose nodes represent test conditions.
5535 INDEX_TYPE is the type of the index of the switch.
5537 Care is taken to prune redundant tests from the decision tree
5538 by detecting any boundary conditions already checked by
5539 emitted rtx. (See node_has_high_bound, node_has_low_bound
5540 and node_is_bounded, above.)
5542 Where the test conditions can be shown to be redundant we emit
5543 an unconditional jump to the target code. As a further
5544 optimization, the subordinates of a tree node are examined to
5545 check for bounded nodes. In this case conditional and/or
5546 unconditional jumps as a result of the boundary check for the
5547 current node are arranged to target the subordinates associated
5548 code for out of bound conditions on the current node node.
5550 We can assume that when control reaches the code generated here,
5551 the index value has already been compared with the parents
5552 of this node, and determined to be on the same side of each parent
5553 as this node is. Thus, if this node tests for the value 51,
5554 and a parent tested for 52, we don't need to consider
5555 the possibility of a value greater than 51. If another parent
5556 tests for the value 50, then this node need not test anything. */
5559 emit_case_nodes (index, node, default_label, index_type)
5565 /* If INDEX has an unsigned type, we must make unsigned branches. */
5566 int unsignedp = TREE_UNSIGNED (index_type);
5567 typedef rtx rtx_function ();
5568 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5569 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5570 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5571 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5572 enum machine_mode mode = GET_MODE (index);
5574 /* See if our parents have already tested everything for us.
5575 If they have, emit an unconditional jump for this node. */
5576 if (node_is_bounded (node, index_type))
5577 emit_jump (label_rtx (node->code_label));
5579 else if (tree_int_cst_equal (node->low, node->high))
5581 /* Node is single valued. First see if the index expression matches
5582 this node and then check our children, if any. */
5584 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5585 label_rtx (node->code_label), unsignedp);
5587 if (node->right != 0 && node->left != 0)
5589 /* This node has children on both sides.
5590 Dispatch to one side or the other
5591 by comparing the index value with this node's value.
5592 If one subtree is bounded, check that one first,
5593 so we can avoid real branches in the tree. */
5595 if (node_is_bounded (node->right, index_type))
5597 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5599 GT, NULL_RTX, mode, unsignedp, 0);
5601 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5602 emit_case_nodes (index, node->left, default_label, index_type);
5605 else if (node_is_bounded (node->left, index_type))
5607 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5609 LT, NULL_RTX, mode, unsignedp, 0);
5610 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5611 emit_case_nodes (index, node->right, default_label, index_type);
5616 /* Neither node is bounded. First distinguish the two sides;
5617 then emit the code for one side at a time. */
5620 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5622 /* See if the value is on the right. */
5623 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5625 GT, NULL_RTX, mode, unsignedp, 0);
5626 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5628 /* Value must be on the left.
5629 Handle the left-hand subtree. */
5630 emit_case_nodes (index, node->left, default_label, index_type);
5631 /* If left-hand subtree does nothing,
5633 emit_jump_if_reachable (default_label);
5635 /* Code branches here for the right-hand subtree. */
5636 expand_label (test_label);
5637 emit_case_nodes (index, node->right, default_label, index_type);
5641 else if (node->right != 0 && node->left == 0)
5643 /* Here we have a right child but no left so we issue conditional
5644 branch to default and process the right child.
5646 Omit the conditional branch to default if we it avoid only one
5647 right child; it costs too much space to save so little time. */
5649 if (node->right->right || node->right->left
5650 || !tree_int_cst_equal (node->right->low, node->right->high))
5652 if (!node_has_low_bound (node, index_type))
5654 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5656 LT, NULL_RTX, mode, unsignedp, 0);
5657 emit_jump_insn ((*gen_blt_pat) (default_label));
5660 emit_case_nodes (index, node->right, default_label, index_type);
5663 /* We cannot process node->right normally
5664 since we haven't ruled out the numbers less than
5665 this node's value. So handle node->right explicitly. */
5666 do_jump_if_equal (index,
5667 expand_expr (node->right->low, NULL_RTX,
5669 label_rtx (node->right->code_label), unsignedp);
5672 else if (node->right == 0 && node->left != 0)
5674 /* Just one subtree, on the left. */
5676 #if 0 /* The following code and comment were formerly part
5677 of the condition here, but they didn't work
5678 and I don't understand what the idea was. -- rms. */
5679 /* If our "most probable entry" is less probable
5680 than the default label, emit a jump to
5681 the default label using condition codes
5682 already lying around. With no right branch,
5683 a branch-greater-than will get us to the default
5686 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5689 if (node->left->left || node->left->right
5690 || !tree_int_cst_equal (node->left->low, node->left->high))
5692 if (!node_has_high_bound (node, index_type))
5694 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5696 GT, NULL_RTX, mode, unsignedp, 0);
5697 emit_jump_insn ((*gen_bgt_pat) (default_label));
5700 emit_case_nodes (index, node->left, default_label, index_type);
5703 /* We cannot process node->left normally
5704 since we haven't ruled out the numbers less than
5705 this node's value. So handle node->left explicitly. */
5706 do_jump_if_equal (index,
5707 expand_expr (node->left->low, NULL_RTX,
5709 label_rtx (node->left->code_label), unsignedp);
5714 /* Node is a range. These cases are very similar to those for a single
5715 value, except that we do not start by testing whether this node
5716 is the one to branch to. */
5718 if (node->right != 0 && node->left != 0)
5720 /* Node has subtrees on both sides.
5721 If the right-hand subtree is bounded,
5722 test for it first, since we can go straight there.
5723 Otherwise, we need to make a branch in the control structure,
5724 then handle the two subtrees. */
5725 tree test_label = 0;
5727 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5729 GT, NULL_RTX, mode, unsignedp, 0);
5731 if (node_is_bounded (node->right, index_type))
5732 /* Right hand node is fully bounded so we can eliminate any
5733 testing and branch directly to the target code. */
5734 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5737 /* Right hand node requires testing.
5738 Branch to a label where we will handle it later. */
5740 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5741 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5744 /* Value belongs to this node or to the left-hand subtree. */
5746 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5747 GE, NULL_RTX, mode, unsignedp, 0);
5748 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5750 /* Handle the left-hand subtree. */
5751 emit_case_nodes (index, node->left, default_label, index_type);
5753 /* If right node had to be handled later, do that now. */
5757 /* If the left-hand subtree fell through,
5758 don't let it fall into the right-hand subtree. */
5759 emit_jump_if_reachable (default_label);
5761 expand_label (test_label);
5762 emit_case_nodes (index, node->right, default_label, index_type);
5766 else if (node->right != 0 && node->left == 0)
5768 /* Deal with values to the left of this node,
5769 if they are possible. */
5770 if (!node_has_low_bound (node, index_type))
5772 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5774 LT, NULL_RTX, mode, unsignedp, 0);
5775 emit_jump_insn ((*gen_blt_pat) (default_label));
5778 /* Value belongs to this node or to the right-hand subtree. */
5780 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5782 LE, NULL_RTX, mode, unsignedp, 0);
5783 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5785 emit_case_nodes (index, node->right, default_label, index_type);
5788 else if (node->right == 0 && node->left != 0)
5790 /* Deal with values to the right of this node,
5791 if they are possible. */
5792 if (!node_has_high_bound (node, index_type))
5794 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5796 GT, NULL_RTX, mode, unsignedp, 0);
5797 emit_jump_insn ((*gen_bgt_pat) (default_label));
5800 /* Value belongs to this node or to the left-hand subtree. */
5802 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5803 GE, NULL_RTX, mode, unsignedp, 0);
5804 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5806 emit_case_nodes (index, node->left, default_label, index_type);
5811 /* Node has no children so we check low and high bounds to remove
5812 redundant tests. Only one of the bounds can exist,
5813 since otherwise this node is bounded--a case tested already. */
5815 if (!node_has_high_bound (node, index_type))
5817 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5819 GT, NULL_RTX, mode, unsignedp, 0);
5820 emit_jump_insn ((*gen_bgt_pat) (default_label));
5823 if (!node_has_low_bound (node, index_type))
5825 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5827 LT, NULL_RTX, mode, unsignedp, 0);
5828 emit_jump_insn ((*gen_blt_pat) (default_label));
5831 emit_jump (label_rtx (node->code_label));
5836 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5837 so that the debugging info will be correct for the unrolled loop. */
5839 /* Indexed by block number, contains a pointer to the N'th block node. */
5841 static tree *block_vector;
5844 find_loop_tree_blocks ()
5846 tree block = DECL_INITIAL (current_function_decl);
5848 /* There first block is for the function body, and does not have
5849 corresponding block notes. Don't include it in the block vector. */
5850 block = BLOCK_SUBBLOCKS (block);
5852 block_vector = identify_blocks (block, get_insns ());
5856 unroll_block_trees ()
5858 tree block = DECL_INITIAL (current_function_decl);
5860 reorder_blocks (block_vector, block, get_insns ());