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 extern rtx bc_allocate_local ();
471 extern rtx bc_allocate_variable_array ();
476 gcc_obstack_init (&stmt_obstack);
478 empty_cleanup_list = build_tree_list (NULL_TREE, NULL_TREE);
483 init_stmt_for_function ()
485 /* We are not currently within any block, conditional, loop or case. */
487 stack_block_stack = 0;
494 block_start_count = 0;
496 /* No gotos have been expanded yet. */
497 goto_fixup_chain = 0;
499 /* We are not processing a ({...}) grouping. */
500 expr_stmts_for_value = 0;
508 p->block_stack = block_stack;
509 p->stack_block_stack = stack_block_stack;
510 p->cond_stack = cond_stack;
511 p->loop_stack = loop_stack;
512 p->case_stack = case_stack;
513 p->nesting_stack = nesting_stack;
514 p->nesting_depth = nesting_depth;
515 p->block_start_count = block_start_count;
516 p->last_expr_type = last_expr_type;
517 p->last_expr_value = last_expr_value;
518 p->expr_stmts_for_value = expr_stmts_for_value;
519 p->emit_filename = emit_filename;
520 p->emit_lineno = emit_lineno;
521 p->goto_fixup_chain = goto_fixup_chain;
525 restore_stmt_status (p)
528 block_stack = p->block_stack;
529 stack_block_stack = p->stack_block_stack;
530 cond_stack = p->cond_stack;
531 loop_stack = p->loop_stack;
532 case_stack = p->case_stack;
533 nesting_stack = p->nesting_stack;
534 nesting_depth = p->nesting_depth;
535 block_start_count = p->block_start_count;
536 last_expr_type = p->last_expr_type;
537 last_expr_value = p->last_expr_value;
538 expr_stmts_for_value = p->expr_stmts_for_value;
539 emit_filename = p->emit_filename;
540 emit_lineno = p->emit_lineno;
541 goto_fixup_chain = p->goto_fixup_chain;
544 /* Emit a no-op instruction. */
551 if (!output_bytecode)
553 last_insn = get_last_insn ();
555 && (GET_CODE (last_insn) == CODE_LABEL
556 || (GET_CODE (last_insn) == NOTE
557 && prev_real_insn (last_insn) == 0)))
558 emit_insn (gen_nop ());
562 /* Return the rtx-label that corresponds to a LABEL_DECL,
563 creating it if necessary. */
569 if (TREE_CODE (label) != LABEL_DECL)
572 if (DECL_RTL (label))
573 return DECL_RTL (label);
575 return DECL_RTL (label) = gen_label_rtx ();
578 /* Add an unconditional jump to LABEL as the next sequential instruction. */
584 do_pending_stack_adjust ();
585 emit_jump_insn (gen_jump (label));
589 /* Emit code to jump to the address
590 specified by the pointer expression EXP. */
593 expand_computed_goto (exp)
598 bc_expand_expr (exp);
599 bc_emit_instruction (jumpP);
603 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
605 #ifdef POINTERS_EXTEND_UNSIGNED
606 x = convert_memory_address (Pmode, x);
610 do_pending_stack_adjust ();
611 emit_indirect_jump (x);
615 /* Handle goto statements and the labels that they can go to. */
617 /* Specify the location in the RTL code of a label LABEL,
618 which is a LABEL_DECL tree node.
620 This is used for the kind of label that the user can jump to with a
621 goto statement, and for alternatives of a switch or case statement.
622 RTL labels generated for loops and conditionals don't go through here;
623 they are generated directly at the RTL level, by other functions below.
625 Note that this has nothing to do with defining label *names*.
626 Languages vary in how they do that and what that even means. */
632 struct label_chain *p;
636 if (! DECL_RTL (label))
637 DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ());
638 if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label))))
639 error ("multiply defined label");
643 do_pending_stack_adjust ();
644 emit_label (label_rtx (label));
645 if (DECL_NAME (label))
646 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
648 if (stack_block_stack != 0)
650 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
651 p->next = stack_block_stack->data.block.label_chain;
652 stack_block_stack->data.block.label_chain = p;
657 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
658 from nested functions. */
661 declare_nonlocal_label (label)
664 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
665 LABEL_PRESERVE_P (label_rtx (label)) = 1;
666 if (nonlocal_goto_handler_slot == 0)
668 nonlocal_goto_handler_slot
669 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
670 emit_stack_save (SAVE_NONLOCAL,
671 &nonlocal_goto_stack_level,
672 PREV_INSN (tail_recursion_reentry));
676 /* Generate RTL code for a `goto' statement with target label LABEL.
677 LABEL should be a LABEL_DECL tree node that was or will later be
678 defined with `expand_label'. */
688 expand_goto_internal (label, label_rtx (label), NULL_RTX);
692 /* Check for a nonlocal goto to a containing function. */
693 context = decl_function_context (label);
694 if (context != 0 && context != current_function_decl)
696 struct function *p = find_function_data (context);
697 rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label));
700 p->has_nonlocal_label = 1;
701 current_function_has_nonlocal_goto = 1;
702 LABEL_REF_NONLOCAL_P (label_ref) = 1;
704 /* Copy the rtl for the slots so that they won't be shared in
705 case the virtual stack vars register gets instantiated differently
706 in the parent than in the child. */
708 #if HAVE_nonlocal_goto
709 if (HAVE_nonlocal_goto)
710 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
711 copy_rtx (p->nonlocal_goto_handler_slot),
712 copy_rtx (p->nonlocal_goto_stack_level),
719 /* Restore frame pointer for containing function.
720 This sets the actual hard register used for the frame pointer
721 to the location of the function's incoming static chain info.
722 The non-local goto handler will then adjust it to contain the
723 proper value and reload the argument pointer, if needed. */
724 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
726 /* We have now loaded the frame pointer hardware register with
727 the address of that corresponds to the start of the virtual
728 stack vars. So replace virtual_stack_vars_rtx in all
729 addresses we use with stack_pointer_rtx. */
731 /* Get addr of containing function's current nonlocal goto handler,
732 which will do any cleanups and then jump to the label. */
733 addr = copy_rtx (p->nonlocal_goto_handler_slot);
734 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
735 hard_frame_pointer_rtx));
737 /* Restore the stack pointer. Note this uses fp just restored. */
738 addr = p->nonlocal_goto_stack_level;
740 addr = replace_rtx (copy_rtx (addr),
741 virtual_stack_vars_rtx,
742 hard_frame_pointer_rtx);
744 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
746 /* Put in the static chain register the nonlocal label address. */
747 emit_move_insn (static_chain_rtx, label_ref);
748 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
750 emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx));
751 emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx));
752 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
753 emit_indirect_jump (temp);
757 expand_goto_internal (label, label_rtx (label), NULL_RTX);
760 /* Generate RTL code for a `goto' statement with target label BODY.
761 LABEL should be a LABEL_REF.
762 LAST_INSN, if non-0, is the rtx we should consider as the last
763 insn emitted (for the purposes of cleaning up a return). */
766 expand_goto_internal (body, label, last_insn)
771 struct nesting *block;
774 /* NOTICE! If a bytecode instruction other than `jump' is needed,
775 then the caller has to call bc_expand_goto_internal()
776 directly. This is rather an exceptional case, and there aren't
777 that many places where this is necessary. */
780 expand_goto_internal (body, label, last_insn);
784 if (GET_CODE (label) != CODE_LABEL)
787 /* If label has already been defined, we can tell now
788 whether and how we must alter the stack level. */
790 if (PREV_INSN (label) != 0)
792 /* Find the innermost pending block that contains the label.
793 (Check containment by comparing insn-uids.)
794 Then restore the outermost stack level within that block,
795 and do cleanups of all blocks contained in it. */
796 for (block = block_stack; block; block = block->next)
798 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
800 if (block->data.block.stack_level != 0)
801 stack_level = block->data.block.stack_level;
802 /* Execute the cleanups for blocks we are exiting. */
803 if (block->data.block.cleanups != 0)
805 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
806 do_pending_stack_adjust ();
812 /* Ensure stack adjust isn't done by emit_jump, as this would clobber
813 the stack pointer. This one should be deleted as dead by flow. */
814 clear_pending_stack_adjust ();
815 do_pending_stack_adjust ();
816 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
819 if (body != 0 && DECL_TOO_LATE (body))
820 error ("jump to `%s' invalidly jumps into binding contour",
821 IDENTIFIER_POINTER (DECL_NAME (body)));
823 /* Label not yet defined: may need to put this goto
824 on the fixup list. */
825 else if (! expand_fixup (body, label, last_insn))
827 /* No fixup needed. Record that the label is the target
828 of at least one goto that has no fixup. */
830 TREE_ADDRESSABLE (body) = 1;
836 /* Generate a jump with OPCODE to the given bytecode LABEL which is
837 found within BODY. */
840 bc_expand_goto_internal (opcode, label, body)
841 enum bytecode_opcode opcode;
842 struct bc_label *label;
845 struct nesting *block;
846 int stack_level = -1;
848 /* If the label is defined, adjust the stack as necessary.
849 If it's not defined, we have to push the reference on the
855 /* Find the innermost pending block that contains the label.
856 (Check containment by comparing bytecode uids.) Then restore the
857 outermost stack level within that block. */
859 for (block = block_stack; block; block = block->next)
861 if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid)
863 if (block->data.block.bc_stack_level)
864 stack_level = block->data.block.bc_stack_level;
866 /* Execute the cleanups for blocks we are exiting. */
867 if (block->data.block.cleanups != 0)
869 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
870 do_pending_stack_adjust ();
874 /* Restore the stack level. If we need to adjust the stack, we
875 must do so after the jump, since the jump may depend on
876 what's on the stack. Thus, any stack-modifying conditional
877 jumps (these are the only ones that rely on what's on the
878 stack) go into the fixup list. */
881 && stack_depth != stack_level
884 bc_expand_fixup (opcode, label, stack_level);
887 if (stack_level >= 0)
888 bc_adjust_stack (stack_depth - stack_level);
890 if (body && DECL_BIT_FIELD (body))
891 error ("jump to `%s' invalidly jumps into binding contour",
892 IDENTIFIER_POINTER (DECL_NAME (body)));
894 /* Emit immediate jump */
895 bc_emit_bytecode (opcode);
896 bc_emit_bytecode_labelref (label);
898 #ifdef DEBUG_PRINT_CODE
899 fputc ('\n', stderr);
904 /* Put goto in the fixup list */
905 bc_expand_fixup (opcode, label, stack_level);
908 /* Generate if necessary a fixup for a goto
909 whose target label in tree structure (if any) is TREE_LABEL
910 and whose target in rtl is RTL_LABEL.
912 If LAST_INSN is nonzero, we pretend that the jump appears
913 after insn LAST_INSN instead of at the current point in the insn stream.
915 The fixup will be used later to insert insns just before the goto.
916 Those insns will restore the stack level as appropriate for the
917 target label, and will (in the case of C++) also invoke any object
918 destructors which have to be invoked when we exit the scopes which
919 are exited by the goto.
921 Value is nonzero if a fixup is made. */
924 expand_fixup (tree_label, rtl_label, last_insn)
929 struct nesting *block, *end_block;
931 /* See if we can recognize which block the label will be output in.
932 This is possible in some very common cases.
933 If we succeed, set END_BLOCK to that block.
934 Otherwise, set it to 0. */
937 && (rtl_label == cond_stack->data.cond.endif_label
938 || rtl_label == cond_stack->data.cond.next_label))
939 end_block = cond_stack;
940 /* If we are in a loop, recognize certain labels which
941 are likely targets. This reduces the number of fixups
942 we need to create. */
944 && (rtl_label == loop_stack->data.loop.start_label
945 || rtl_label == loop_stack->data.loop.end_label
946 || rtl_label == loop_stack->data.loop.continue_label))
947 end_block = loop_stack;
951 /* Now set END_BLOCK to the binding level to which we will return. */
955 struct nesting *next_block = end_block->all;
958 /* First see if the END_BLOCK is inside the innermost binding level.
959 If so, then no cleanups or stack levels are relevant. */
960 while (next_block && next_block != block)
961 next_block = next_block->all;
966 /* Otherwise, set END_BLOCK to the innermost binding level
967 which is outside the relevant control-structure nesting. */
968 next_block = block_stack->next;
969 for (block = block_stack; block != end_block; block = block->all)
970 if (block == next_block)
971 next_block = next_block->next;
972 end_block = next_block;
975 /* Does any containing block have a stack level or cleanups?
976 If not, no fixup is needed, and that is the normal case
977 (the only case, for standard C). */
978 for (block = block_stack; block != end_block; block = block->next)
979 if (block->data.block.stack_level != 0
980 || block->data.block.cleanups != 0)
983 if (block != end_block)
985 /* Ok, a fixup is needed. Add a fixup to the list of such. */
986 struct goto_fixup *fixup
987 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
988 /* In case an old stack level is restored, make sure that comes
989 after any pending stack adjust. */
990 /* ?? If the fixup isn't to come at the present position,
991 doing the stack adjust here isn't useful. Doing it with our
992 settings at that location isn't useful either. Let's hope
995 do_pending_stack_adjust ();
996 fixup->target = tree_label;
997 fixup->target_rtl = rtl_label;
999 /* Create a BLOCK node and a corresponding matched set of
1000 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
1001 this point. The notes will encapsulate any and all fixup
1002 code which we might later insert at this point in the insn
1003 stream. Also, the BLOCK node will be the parent (i.e. the
1004 `SUPERBLOCK') of any other BLOCK nodes which we might create
1005 later on when we are expanding the fixup code. */
1008 register rtx original_before_jump
1009 = last_insn ? last_insn : get_last_insn ();
1013 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1014 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1015 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
1017 emit_insns_after (fixup->before_jump, original_before_jump);
1020 fixup->block_start_count = block_start_count;
1021 fixup->stack_level = 0;
1022 fixup->cleanup_list_list
1023 = (((block->data.block.outer_cleanups
1025 && block->data.block.outer_cleanups != empty_cleanup_list
1028 || block->data.block.cleanups)
1029 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1030 block->data.block.outer_cleanups)
1032 fixup->next = goto_fixup_chain;
1033 goto_fixup_chain = fixup;
1040 /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL.
1041 Make the fixup restore the stack level to STACK_LEVEL. */
1044 bc_expand_fixup (opcode, label, stack_level)
1045 enum bytecode_opcode opcode;
1046 struct bc_label *label;
1049 struct goto_fixup *fixup
1050 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
1052 fixup->label = bc_get_bytecode_label ();
1053 fixup->bc_target = label;
1054 fixup->bc_stack_level = stack_level;
1055 fixup->bc_handled = FALSE;
1057 fixup->next = goto_fixup_chain;
1058 goto_fixup_chain = fixup;
1060 /* Insert a jump to the fixup code */
1061 bc_emit_bytecode (opcode);
1062 bc_emit_bytecode_labelref (fixup->label);
1064 #ifdef DEBUG_PRINT_CODE
1065 fputc ('\n', stderr);
1069 /* Expand any needed fixups in the outputmost binding level of the
1070 function. FIRST_INSN is the first insn in the function. */
1073 expand_fixups (first_insn)
1076 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1079 /* When exiting a binding contour, process all pending gotos requiring fixups.
1080 THISBLOCK is the structure that describes the block being exited.
1081 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1082 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1083 FIRST_INSN is the insn that began this contour.
1085 Gotos that jump out of this contour must restore the
1086 stack level and do the cleanups before actually jumping.
1088 DONT_JUMP_IN nonzero means report error there is a jump into this
1089 contour from before the beginning of the contour.
1090 This is also done if STACK_LEVEL is nonzero. */
1093 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1094 struct nesting *thisblock;
1100 register struct goto_fixup *f, *prev;
1102 if (output_bytecode)
1104 /* ??? The second arg is the bc stack level, which is not the same
1105 as STACK_LEVEL. I have no idea what should go here, so I'll
1107 bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in);
1111 /* F is the fixup we are considering; PREV is the previous one. */
1112 /* We run this loop in two passes so that cleanups of exited blocks
1113 are run first, and blocks that are exited are marked so
1116 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1118 /* Test for a fixup that is inactive because it is already handled. */
1119 if (f->before_jump == 0)
1121 /* Delete inactive fixup from the chain, if that is easy to do. */
1123 prev->next = f->next;
1125 /* Has this fixup's target label been defined?
1126 If so, we can finalize it. */
1127 else if (PREV_INSN (f->target_rtl) != 0)
1129 register rtx cleanup_insns;
1131 /* Get the first non-label after the label
1132 this goto jumps to. If that's before this scope begins,
1133 we don't have a jump into the scope. */
1134 rtx after_label = f->target_rtl;
1135 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
1136 after_label = NEXT_INSN (after_label);
1138 /* If this fixup jumped into this contour from before the beginning
1139 of this contour, report an error. */
1140 /* ??? Bug: this does not detect jumping in through intermediate
1141 blocks that have stack levels or cleanups.
1142 It detects only a problem with the innermost block
1143 around the label. */
1145 && (dont_jump_in || stack_level || cleanup_list)
1146 /* If AFTER_LABEL is 0, it means the jump goes to the end
1147 of the rtl, which means it jumps into this scope. */
1148 && (after_label == 0
1149 || INSN_UID (first_insn) < INSN_UID (after_label))
1150 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1151 && ! DECL_REGISTER (f->target))
1153 error_with_decl (f->target,
1154 "label `%s' used before containing binding contour");
1155 /* Prevent multiple errors for one label. */
1156 DECL_REGISTER (f->target) = 1;
1159 /* We will expand the cleanups into a sequence of their own and
1160 then later on we will attach this new sequence to the insn
1161 stream just ahead of the actual jump insn. */
1165 /* Temporarily restore the lexical context where we will
1166 logically be inserting the fixup code. We do this for the
1167 sake of getting the debugging information right. */
1170 set_block (f->context);
1172 /* Expand the cleanups for blocks this jump exits. */
1173 if (f->cleanup_list_list)
1176 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1177 /* Marked elements correspond to blocks that have been closed.
1178 Do their cleanups. */
1179 if (TREE_ADDRESSABLE (lists)
1180 && TREE_VALUE (lists) != 0)
1182 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1183 /* Pop any pushes done in the cleanups,
1184 in case function is about to return. */
1185 do_pending_stack_adjust ();
1189 /* Restore stack level for the biggest contour that this
1190 jump jumps out of. */
1192 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1194 /* Finish up the sequence containing the insns which implement the
1195 necessary cleanups, and then attach that whole sequence to the
1196 insn stream just ahead of the actual jump insn. Attaching it
1197 at that point insures that any cleanups which are in fact
1198 implicit C++ object destructions (which must be executed upon
1199 leaving the block) appear (to the debugger) to be taking place
1200 in an area of the generated code where the object(s) being
1201 destructed are still "in scope". */
1203 cleanup_insns = get_insns ();
1207 emit_insns_after (cleanup_insns, f->before_jump);
1214 /* For any still-undefined labels, do the cleanups for this block now.
1215 We must do this now since items in the cleanup list may go out
1216 of scope when the block ends. */
1217 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1218 if (f->before_jump != 0
1219 && PREV_INSN (f->target_rtl) == 0
1220 /* Label has still not appeared. If we are exiting a block with
1221 a stack level to restore, that started before the fixup,
1222 mark this stack level as needing restoration
1223 when the fixup is later finalized. */
1225 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1226 means the label is undefined. That's erroneous, but possible. */
1227 && (thisblock->data.block.block_start_count
1228 <= f->block_start_count))
1230 tree lists = f->cleanup_list_list;
1233 for (; lists; lists = TREE_CHAIN (lists))
1234 /* If the following elt. corresponds to our containing block
1235 then the elt. must be for this block. */
1236 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1240 set_block (f->context);
1241 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1242 do_pending_stack_adjust ();
1243 cleanup_insns = get_insns ();
1247 = emit_insns_after (cleanup_insns, f->before_jump);
1249 f->cleanup_list_list = TREE_CHAIN (lists);
1253 f->stack_level = stack_level;
1258 /* When exiting a binding contour, process all pending gotos requiring fixups.
1259 Note: STACK_DEPTH is not altered.
1261 The arguments are currently not used in the bytecode compiler, but we may
1262 need them one day for languages other than C.
1264 THISBLOCK is the structure that describes the block being exited.
1265 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1266 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1267 FIRST_INSN is the insn that began this contour.
1269 Gotos that jump out of this contour must restore the
1270 stack level and do the cleanups before actually jumping.
1272 DONT_JUMP_IN nonzero means report error there is a jump into this
1273 contour from before the beginning of the contour.
1274 This is also done if STACK_LEVEL is nonzero. */
1277 bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1278 struct nesting *thisblock;
1284 register struct goto_fixup *f, *prev;
1285 int saved_stack_depth;
1287 /* F is the fixup we are considering; PREV is the previous one. */
1289 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1291 /* Test for a fixup that is inactive because it is already handled. */
1292 if (f->before_jump == 0)
1294 /* Delete inactive fixup from the chain, if that is easy to do. */
1296 prev->next = f->next;
1299 /* Emit code to restore the stack and continue */
1300 bc_emit_bytecode_labeldef (f->label);
1302 /* Save stack_depth across call, since bc_adjust_stack () will alter
1303 the perceived stack depth via the instructions generated. */
1305 if (f->bc_stack_level >= 0)
1307 saved_stack_depth = stack_depth;
1308 bc_adjust_stack (stack_depth - f->bc_stack_level);
1309 stack_depth = saved_stack_depth;
1312 bc_emit_bytecode (jump);
1313 bc_emit_bytecode_labelref (f->bc_target);
1315 #ifdef DEBUG_PRINT_CODE
1316 fputc ('\n', stderr);
1320 goto_fixup_chain = NULL;
1323 /* Generate RTL for an asm statement (explicit assembler code).
1324 BODY is a STRING_CST node containing the assembler code text,
1325 or an ADDR_EXPR containing a STRING_CST. */
1331 if (output_bytecode)
1333 error ("`asm' is invalid when generating bytecode");
1337 if (TREE_CODE (body) == ADDR_EXPR)
1338 body = TREE_OPERAND (body, 0);
1340 emit_insn (gen_rtx (ASM_INPUT, VOIDmode,
1341 TREE_STRING_POINTER (body)));
1345 /* Generate RTL for an asm statement with arguments.
1346 STRING is the instruction template.
1347 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1348 Each output or input has an expression in the TREE_VALUE and
1349 a constraint-string in the TREE_PURPOSE.
1350 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1351 that is clobbered by this insn.
1353 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1354 Some elements of OUTPUTS may be replaced with trees representing temporary
1355 values. The caller should copy those temporary values to the originally
1358 VOL nonzero means the insn is volatile; don't optimize it. */
1361 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1362 tree string, outputs, inputs, clobbers;
1367 rtvec argvec, constraints;
1369 int ninputs = list_length (inputs);
1370 int noutputs = list_length (outputs);
1374 /* Vector of RTX's of evaluated output operands. */
1375 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1376 /* The insn we have emitted. */
1379 if (output_bytecode)
1381 error ("`asm' is invalid when generating bytecode");
1385 /* Count the number of meaningful clobbered registers, ignoring what
1386 we would ignore later. */
1388 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1390 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1391 i = decode_reg_name (regname);
1392 if (i >= 0 || i == -4)
1395 error ("unknown register name `%s' in `asm'", regname);
1400 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1402 tree val = TREE_VALUE (tail);
1403 tree type = TREE_TYPE (val);
1406 int found_equal = 0;
1409 /* If there's an erroneous arg, emit no insn. */
1410 if (TREE_TYPE (val) == error_mark_node)
1413 /* Make sure constraint has `=' and does not have `+'. Also, see
1414 if it allows any register. Be liberal on the latter test, since
1415 the worst that happens if we get it wrong is we issue an error
1418 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1419 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1422 error ("output operand constraint contains `+'");
1429 case '?': case '!': case '*': case '%': case '&':
1430 case '0': case '1': case '2': case '3': case '4':
1431 case 'V': case 'm': case 'o': case '<': case '>':
1432 case 'E': case 'F': case 'G': case 'H': case 'X':
1433 case 's': case 'i': case 'n':
1434 case 'I': case 'J': case 'K': case 'L': case 'M':
1435 case 'N': case 'O': case 'P': case ',':
1436 #ifdef EXTRA_CONSTRAINT
1437 case 'Q': case 'R': case 'S': case 'T': case 'U':
1441 case 'p': case 'g': case 'r':
1449 error ("output operand constraint lacks `='");
1453 /* If an output operand is not a decl or indirect ref and our constraint
1454 allows a register, make a temporary to act as an intermediate.
1455 Make the asm insn write into that, then our caller will copy it to
1456 the real output operand. Likewise for promoted variables. */
1458 if (TREE_CODE (val) == INDIRECT_REF
1459 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1460 && ! (GET_CODE (DECL_RTL (val)) == REG
1461 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1465 mark_addressable (TREE_VALUE (tail));
1468 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1470 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1471 error ("output number %d not directly addressable", i);
1475 if (TYPE_MODE (type) == BLKmode)
1477 output_rtx[i] = assign_stack_temp (BLKmode,
1478 int_size_in_bytes (type), 0);
1479 MEM_IN_STRUCT_P (output_rtx[i]) = AGGREGATE_TYPE_P (type);
1482 output_rtx[i] = gen_reg_rtx (TYPE_MODE (type));
1484 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1488 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1490 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1494 /* Make vectors for the expression-rtx and constraint strings. */
1496 argvec = rtvec_alloc (ninputs);
1497 constraints = rtvec_alloc (ninputs);
1499 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1500 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1502 MEM_VOLATILE_P (body) = vol;
1504 /* Eval the inputs and put them into ARGVEC.
1505 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1508 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1513 /* If there's an erroneous arg, emit no insn,
1514 because the ASM_INPUT would get VOIDmode
1515 and that could cause a crash in reload. */
1516 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1518 if (TREE_PURPOSE (tail) == NULL_TREE)
1520 error ("hard register `%s' listed as input operand to `asm'",
1521 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1525 /* Make sure constraint has neither `=' nor `+'. */
1527 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1528 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1531 error ("input operand constraint contains `%c'",
1532 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1535 case '?': case '!': case '*': case '%': case '&':
1536 case 'V': case 'm': case 'o': case '<': case '>':
1537 case 'E': case 'F': case 'G': case 'H': case 'X':
1538 case 's': case 'i': case 'n':
1539 case 'I': case 'J': case 'K': case 'L': case 'M':
1540 case 'N': case 'O': case 'P': case ',':
1541 #ifdef EXTRA_CONSTRAINT
1542 case 'Q': case 'R': case 'S': case 'T': case 'U':
1546 case '0': case '1': case '2': case '3': case '4':
1547 case 'p': case 'g': case 'r':
1554 mark_addressable (TREE_VALUE (tail));
1556 XVECEXP (body, 3, i) /* argvec */
1557 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1558 if (CONSTANT_P (XVECEXP (body, 3, i))
1559 && ! general_operand (XVECEXP (body, 3, i),
1560 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1563 XVECEXP (body, 3, i)
1564 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1565 XVECEXP (body, 3, i));
1567 XVECEXP (body, 3, i)
1568 = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1569 XVECEXP (body, 3, i));
1573 && (GET_CODE (XVECEXP (body, 3, i)) == REG
1574 || GET_CODE (XVECEXP (body, 3, i)) == SUBREG
1575 || GET_CODE (XVECEXP (body, 3, i)) == CONCAT))
1577 tree type = TREE_TYPE (TREE_VALUE (tail));
1578 rtx memloc = assign_stack_temp (TYPE_MODE (type),
1579 int_size_in_bytes (type), 1);
1581 MEM_IN_STRUCT_P (memloc) = AGGREGATE_TYPE_P (type);
1582 emit_move_insn (memloc, XVECEXP (body, 3, i));
1583 XVECEXP (body, 3, i) = memloc;
1586 XVECEXP (body, 4, i) /* constraints */
1587 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1588 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1592 /* Protect all the operands from the queue,
1593 now that they have all been evaluated. */
1595 for (i = 0; i < ninputs; i++)
1596 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1598 for (i = 0; i < noutputs; i++)
1599 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1601 /* Now, for each output, construct an rtx
1602 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1603 ARGVEC CONSTRAINTS))
1604 If there is more than one, put them inside a PARALLEL. */
1606 if (noutputs == 1 && nclobbers == 0)
1608 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1609 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1611 else if (noutputs == 0 && nclobbers == 0)
1613 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1614 insn = emit_insn (body);
1620 if (num == 0) num = 1;
1621 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1623 /* For each output operand, store a SET. */
1625 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1627 XVECEXP (body, 0, i)
1628 = gen_rtx (SET, VOIDmode,
1630 gen_rtx (ASM_OPERANDS, VOIDmode,
1631 TREE_STRING_POINTER (string),
1632 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1633 i, argvec, constraints,
1635 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1638 /* If there are no outputs (but there are some clobbers)
1639 store the bare ASM_OPERANDS into the PARALLEL. */
1642 XVECEXP (body, 0, i++) = obody;
1644 /* Store (clobber REG) for each clobbered register specified. */
1646 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1648 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1649 int j = decode_reg_name (regname);
1653 if (j == -3) /* `cc', which is not a register */
1656 if (j == -4) /* `memory', don't cache memory across asm */
1658 XVECEXP (body, 0, i++)
1659 = gen_rtx (CLOBBER, VOIDmode,
1660 gen_rtx (MEM, BLKmode,
1661 gen_rtx (SCRATCH, VOIDmode, 0)));
1665 /* Ignore unknown register, error already signalled. */
1669 /* Use QImode since that's guaranteed to clobber just one reg. */
1670 XVECEXP (body, 0, i++)
1671 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1674 insn = emit_insn (body);
1680 /* Generate RTL to evaluate the expression EXP
1681 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1684 expand_expr_stmt (exp)
1687 if (output_bytecode)
1689 int org_stack_depth = stack_depth;
1691 bc_expand_expr (exp);
1693 /* Restore stack depth */
1694 if (stack_depth < org_stack_depth)
1697 bc_emit_instruction (drop);
1699 last_expr_type = TREE_TYPE (exp);
1703 /* If -W, warn about statements with no side effects,
1704 except for an explicit cast to void (e.g. for assert()), and
1705 except inside a ({...}) where they may be useful. */
1706 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1708 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1709 && !(TREE_CODE (exp) == CONVERT_EXPR
1710 && TREE_TYPE (exp) == void_type_node))
1711 warning_with_file_and_line (emit_filename, emit_lineno,
1712 "statement with no effect");
1713 else if (warn_unused)
1714 warn_if_unused_value (exp);
1717 /* If EXP is of function type and we are expanding statements for
1718 value, convert it to pointer-to-function. */
1719 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1720 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1722 last_expr_type = TREE_TYPE (exp);
1723 if (! flag_syntax_only)
1724 last_expr_value = expand_expr (exp,
1725 (expr_stmts_for_value
1726 ? NULL_RTX : const0_rtx),
1729 /* If all we do is reference a volatile value in memory,
1730 copy it to a register to be sure it is actually touched. */
1731 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1732 && TREE_THIS_VOLATILE (exp))
1734 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1736 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1737 copy_to_reg (last_expr_value);
1740 rtx lab = gen_label_rtx ();
1742 /* Compare the value with itself to reference it. */
1743 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1744 expand_expr (TYPE_SIZE (last_expr_type),
1745 NULL_RTX, VOIDmode, 0),
1747 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1748 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1753 /* If this expression is part of a ({...}) and is in memory, we may have
1754 to preserve temporaries. */
1755 preserve_temp_slots (last_expr_value);
1757 /* Free any temporaries used to evaluate this expression. Any temporary
1758 used as a result of this expression will already have been preserved
1765 /* Warn if EXP contains any computations whose results are not used.
1766 Return 1 if a warning is printed; 0 otherwise. */
1769 warn_if_unused_value (exp)
1772 if (TREE_USED (exp))
1775 switch (TREE_CODE (exp))
1777 case PREINCREMENT_EXPR:
1778 case POSTINCREMENT_EXPR:
1779 case PREDECREMENT_EXPR:
1780 case POSTDECREMENT_EXPR:
1785 case METHOD_CALL_EXPR:
1787 case WITH_CLEANUP_EXPR:
1789 /* We don't warn about COND_EXPR because it may be a useful
1790 construct if either arm contains a side effect. */
1795 /* For a binding, warn if no side effect within it. */
1796 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1799 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1801 case TRUTH_ORIF_EXPR:
1802 case TRUTH_ANDIF_EXPR:
1803 /* In && or ||, warn if 2nd operand has no side effect. */
1804 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1807 if (TREE_NO_UNUSED_WARNING (exp))
1809 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1811 /* Let people do `(foo (), 0)' without a warning. */
1812 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1814 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1818 case NON_LVALUE_EXPR:
1819 /* Don't warn about values cast to void. */
1820 if (TREE_TYPE (exp) == void_type_node)
1822 /* Don't warn about conversions not explicit in the user's program. */
1823 if (TREE_NO_UNUSED_WARNING (exp))
1825 /* Assignment to a cast usually results in a cast of a modify.
1826 Don't complain about that. There can be an arbitrary number of
1827 casts before the modify, so we must loop until we find the first
1828 non-cast expression and then test to see if that is a modify. */
1830 tree tem = TREE_OPERAND (exp, 0);
1832 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1833 tem = TREE_OPERAND (tem, 0);
1835 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1836 || TREE_CODE (tem) == CALL_EXPR)
1842 /* Don't warn about automatic dereferencing of references, since
1843 the user cannot control it. */
1844 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1845 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1846 /* ... fall through ... */
1849 /* Referencing a volatile value is a side effect, so don't warn. */
1850 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1851 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1852 && TREE_THIS_VOLATILE (exp))
1855 warning_with_file_and_line (emit_filename, emit_lineno,
1856 "value computed is not used");
1861 /* Clear out the memory of the last expression evaluated. */
1869 /* Begin a statement which will return a value.
1870 Return the RTL_EXPR for this statement expr.
1871 The caller must save that value and pass it to expand_end_stmt_expr. */
1874 expand_start_stmt_expr ()
1879 /* When generating bytecode just note down the stack depth */
1880 if (output_bytecode)
1881 return (build_int_2 (stack_depth, 0));
1883 /* Make the RTL_EXPR node temporary, not momentary,
1884 so that rtl_expr_chain doesn't become garbage. */
1885 momentary = suspend_momentary ();
1886 t = make_node (RTL_EXPR);
1887 resume_momentary (momentary);
1888 do_pending_stack_adjust ();
1889 start_sequence_for_rtl_expr (t);
1891 expr_stmts_for_value++;
1895 /* Restore the previous state at the end of a statement that returns a value.
1896 Returns a tree node representing the statement's value and the
1897 insns to compute the value.
1899 The nodes of that expression have been freed by now, so we cannot use them.
1900 But we don't want to do that anyway; the expression has already been
1901 evaluated and now we just want to use the value. So generate a RTL_EXPR
1902 with the proper type and RTL value.
1904 If the last substatement was not an expression,
1905 return something with type `void'. */
1908 expand_end_stmt_expr (t)
1911 if (output_bytecode)
1917 /* At this point, all expressions have been evaluated in order.
1918 However, all expression values have been popped when evaluated,
1919 which means we have to recover the last expression value. This is
1920 the last value removed by means of a `drop' instruction. Instead
1921 of adding code to inhibit dropping the last expression value, it
1922 is here recovered by undoing the `drop'. Since `drop' is
1923 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1926 bc_adjust_stack (-1);
1928 if (!last_expr_type)
1929 last_expr_type = void_type_node;
1931 t = make_node (RTL_EXPR);
1932 TREE_TYPE (t) = last_expr_type;
1933 RTL_EXPR_RTL (t) = NULL;
1934 RTL_EXPR_SEQUENCE (t) = NULL;
1936 /* Don't consider deleting this expr or containing exprs at tree level. */
1937 TREE_THIS_VOLATILE (t) = 1;
1945 if (last_expr_type == 0)
1947 last_expr_type = void_type_node;
1948 last_expr_value = const0_rtx;
1950 else if (last_expr_value == 0)
1951 /* There are some cases where this can happen, such as when the
1952 statement is void type. */
1953 last_expr_value = const0_rtx;
1954 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1955 /* Remove any possible QUEUED. */
1956 last_expr_value = protect_from_queue (last_expr_value, 0);
1960 TREE_TYPE (t) = last_expr_type;
1961 RTL_EXPR_RTL (t) = last_expr_value;
1962 RTL_EXPR_SEQUENCE (t) = get_insns ();
1964 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1968 /* Don't consider deleting this expr or containing exprs at tree level. */
1969 TREE_SIDE_EFFECTS (t) = 1;
1970 /* Propagate volatility of the actual RTL expr. */
1971 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1974 expr_stmts_for_value--;
1979 /* Generate RTL for the start of an if-then. COND is the expression
1980 whose truth should be tested.
1982 If EXITFLAG is nonzero, this conditional is visible to
1983 `exit_something'. */
1986 expand_start_cond (cond, exitflag)
1990 struct nesting *thiscond = ALLOC_NESTING ();
1992 /* Make an entry on cond_stack for the cond we are entering. */
1994 thiscond->next = cond_stack;
1995 thiscond->all = nesting_stack;
1996 thiscond->depth = ++nesting_depth;
1997 thiscond->data.cond.next_label = gen_label_rtx ();
1998 /* Before we encounter an `else', we don't need a separate exit label
1999 unless there are supposed to be exit statements
2000 to exit this conditional. */
2001 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2002 thiscond->data.cond.endif_label = thiscond->exit_label;
2003 cond_stack = thiscond;
2004 nesting_stack = thiscond;
2006 if (output_bytecode)
2007 bc_expand_start_cond (cond, exitflag);
2009 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2012 /* Generate RTL between then-clause and the elseif-clause
2013 of an if-then-elseif-.... */
2016 expand_start_elseif (cond)
2019 if (cond_stack->data.cond.endif_label == 0)
2020 cond_stack->data.cond.endif_label = gen_label_rtx ();
2021 emit_jump (cond_stack->data.cond.endif_label);
2022 emit_label (cond_stack->data.cond.next_label);
2023 cond_stack->data.cond.next_label = gen_label_rtx ();
2024 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2027 /* Generate RTL between the then-clause and the else-clause
2028 of an if-then-else. */
2031 expand_start_else ()
2033 if (cond_stack->data.cond.endif_label == 0)
2034 cond_stack->data.cond.endif_label = gen_label_rtx ();
2036 if (output_bytecode)
2038 bc_expand_start_else ();
2042 emit_jump (cond_stack->data.cond.endif_label);
2043 emit_label (cond_stack->data.cond.next_label);
2044 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2047 /* After calling expand_start_else, turn this "else" into an "else if"
2048 by providing another condition. */
2051 expand_elseif (cond)
2054 cond_stack->data.cond.next_label = gen_label_rtx ();
2055 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2058 /* Generate RTL for the end of an if-then.
2059 Pop the record for it off of cond_stack. */
2064 struct nesting *thiscond = cond_stack;
2066 if (output_bytecode)
2067 bc_expand_end_cond ();
2070 do_pending_stack_adjust ();
2071 if (thiscond->data.cond.next_label)
2072 emit_label (thiscond->data.cond.next_label);
2073 if (thiscond->data.cond.endif_label)
2074 emit_label (thiscond->data.cond.endif_label);
2077 POPSTACK (cond_stack);
2082 /* Generate code for the start of an if-then. COND is the expression
2083 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2084 is to be visible to exit_something. It is assumed that the caller
2085 has pushed the previous context on the cond stack. */
2088 bc_expand_start_cond (cond, exitflag)
2092 struct nesting *thiscond = cond_stack;
2094 thiscond->data.case_stmt.nominal_type = cond;
2096 thiscond->exit_label = gen_label_rtx ();
2097 bc_expand_expr (cond);
2098 bc_emit_bytecode (xjumpifnot);
2099 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2101 #ifdef DEBUG_PRINT_CODE
2102 fputc ('\n', stderr);
2106 /* Generate the label for the end of an if with
2110 bc_expand_end_cond ()
2112 struct nesting *thiscond = cond_stack;
2114 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2117 /* Generate code for the start of the else- clause of
2121 bc_expand_start_else ()
2123 struct nesting *thiscond = cond_stack;
2125 thiscond->data.cond.endif_label = thiscond->exit_label;
2126 thiscond->exit_label = gen_label_rtx ();
2127 bc_emit_bytecode (jump);
2128 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2130 #ifdef DEBUG_PRINT_CODE
2131 fputc ('\n', stderr);
2134 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2137 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2138 loop should be exited by `exit_something'. This is a loop for which
2139 `expand_continue' will jump to the top of the loop.
2141 Make an entry on loop_stack to record the labels associated with
2145 expand_start_loop (exit_flag)
2148 register struct nesting *thisloop = ALLOC_NESTING ();
2150 /* Make an entry on loop_stack for the loop we are entering. */
2152 thisloop->next = loop_stack;
2153 thisloop->all = nesting_stack;
2154 thisloop->depth = ++nesting_depth;
2155 thisloop->data.loop.start_label = gen_label_rtx ();
2156 thisloop->data.loop.end_label = gen_label_rtx ();
2157 thisloop->data.loop.alt_end_label = 0;
2158 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2159 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2160 loop_stack = thisloop;
2161 nesting_stack = thisloop;
2163 if (output_bytecode)
2165 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2169 do_pending_stack_adjust ();
2171 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2172 emit_label (thisloop->data.loop.start_label);
2177 /* Like expand_start_loop but for a loop where the continuation point
2178 (for expand_continue_loop) will be specified explicitly. */
2181 expand_start_loop_continue_elsewhere (exit_flag)
2184 struct nesting *thisloop = expand_start_loop (exit_flag);
2185 loop_stack->data.loop.continue_label = gen_label_rtx ();
2189 /* Specify the continuation point for a loop started with
2190 expand_start_loop_continue_elsewhere.
2191 Use this at the point in the code to which a continue statement
2195 expand_loop_continue_here ()
2197 if (output_bytecode)
2199 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2202 do_pending_stack_adjust ();
2203 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2204 emit_label (loop_stack->data.loop.continue_label);
2210 bc_expand_end_loop ()
2212 struct nesting *thisloop = loop_stack;
2214 bc_emit_bytecode (jump);
2215 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2217 #ifdef DEBUG_PRINT_CODE
2218 fputc ('\n', stderr);
2221 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2222 POPSTACK (loop_stack);
2227 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2228 Pop the block off of loop_stack. */
2234 register rtx start_label;
2235 rtx last_test_insn = 0;
2238 if (output_bytecode)
2240 bc_expand_end_loop ();
2244 insn = get_last_insn ();
2245 start_label = loop_stack->data.loop.start_label;
2247 /* Mark the continue-point at the top of the loop if none elsewhere. */
2248 if (start_label == loop_stack->data.loop.continue_label)
2249 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2251 do_pending_stack_adjust ();
2253 /* If optimizing, perhaps reorder the loop. If the loop
2254 starts with a conditional exit, roll that to the end
2255 where it will optimize together with the jump back.
2257 We look for the last conditional branch to the exit that we encounter
2258 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2259 branch to the exit first, use it.
2261 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2262 because moving them is not valid. */
2266 ! (GET_CODE (insn) == JUMP_INSN
2267 && GET_CODE (PATTERN (insn)) == SET
2268 && SET_DEST (PATTERN (insn)) == pc_rtx
2269 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2271 /* Scan insns from the top of the loop looking for a qualified
2272 conditional exit. */
2273 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2274 insn = NEXT_INSN (insn))
2276 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2279 if (GET_CODE (insn) == NOTE
2280 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2281 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2284 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2287 if (last_test_insn && num_insns > 30)
2290 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2291 && SET_DEST (PATTERN (insn)) == pc_rtx
2292 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2293 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2294 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2295 == loop_stack->data.loop.end_label)
2296 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2297 == loop_stack->data.loop.alt_end_label)))
2298 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2299 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2300 == loop_stack->data.loop.end_label)
2301 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2302 == loop_stack->data.loop.alt_end_label)))))
2303 last_test_insn = insn;
2305 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2306 && GET_CODE (PATTERN (insn)) == SET
2307 && SET_DEST (PATTERN (insn)) == pc_rtx
2308 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2309 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2310 == loop_stack->data.loop.end_label)
2311 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2312 == loop_stack->data.loop.alt_end_label)))
2313 /* Include BARRIER. */
2314 last_test_insn = NEXT_INSN (insn);
2317 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2319 /* We found one. Move everything from there up
2320 to the end of the loop, and add a jump into the loop
2321 to jump to there. */
2322 register rtx newstart_label = gen_label_rtx ();
2323 register rtx start_move = start_label;
2325 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2326 then we want to move this note also. */
2327 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2328 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2329 == NOTE_INSN_LOOP_CONT))
2330 start_move = PREV_INSN (start_move);
2332 emit_label_after (newstart_label, PREV_INSN (start_move));
2333 reorder_insns (start_move, last_test_insn, get_last_insn ());
2334 emit_jump_insn_after (gen_jump (start_label),
2335 PREV_INSN (newstart_label));
2336 emit_barrier_after (PREV_INSN (newstart_label));
2337 start_label = newstart_label;
2341 emit_jump (start_label);
2342 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2343 emit_label (loop_stack->data.loop.end_label);
2345 POPSTACK (loop_stack);
2350 /* Generate a jump to the current loop's continue-point.
2351 This is usually the top of the loop, but may be specified
2352 explicitly elsewhere. If not currently inside a loop,
2353 return 0 and do nothing; caller will print an error message. */
2356 expand_continue_loop (whichloop)
2357 struct nesting *whichloop;
2361 whichloop = loop_stack;
2364 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2369 /* Generate a jump to exit the current loop. If not currently inside a loop,
2370 return 0 and do nothing; caller will print an error message. */
2373 expand_exit_loop (whichloop)
2374 struct nesting *whichloop;
2378 whichloop = loop_stack;
2381 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2385 /* Generate a conditional jump to exit the current loop if COND
2386 evaluates to zero. If not currently inside a loop,
2387 return 0 and do nothing; caller will print an error message. */
2390 expand_exit_loop_if_false (whichloop, cond)
2391 struct nesting *whichloop;
2396 whichloop = loop_stack;
2399 if (output_bytecode)
2401 bc_expand_expr (cond);
2402 bc_expand_goto_internal (xjumpifnot,
2403 BYTECODE_BC_LABEL (whichloop->exit_label),
2408 /* In order to handle fixups, we actually create a conditional jump
2409 around a unconditional branch to exit the loop. If fixups are
2410 necessary, they go before the unconditional branch. */
2412 rtx label = gen_label_rtx ();
2415 do_jump (cond, NULL_RTX, label);
2416 last_insn = get_last_insn ();
2417 if (GET_CODE (last_insn) == CODE_LABEL)
2418 whichloop->data.loop.alt_end_label = last_insn;
2419 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2427 /* Return non-zero if we should preserve sub-expressions as separate
2428 pseudos. We never do so if we aren't optimizing. We always do so
2429 if -fexpensive-optimizations.
2431 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2432 the loop may still be a small one. */
2435 preserve_subexpressions_p ()
2439 if (flag_expensive_optimizations)
2442 if (optimize == 0 || loop_stack == 0)
2445 insn = get_last_insn_anywhere ();
2448 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2449 < n_non_fixed_regs * 3));
2453 /* Generate a jump to exit the current loop, conditional, binding contour
2454 or case statement. Not all such constructs are visible to this function,
2455 only those started with EXIT_FLAG nonzero. Individual languages use
2456 the EXIT_FLAG parameter to control which kinds of constructs you can
2459 If not currently inside anything that can be exited,
2460 return 0 and do nothing; caller will print an error message. */
2463 expand_exit_something ()
2467 for (n = nesting_stack; n; n = n->all)
2468 if (n->exit_label != 0)
2470 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2477 /* Generate RTL to return from the current function, with no value.
2478 (That is, we do not do anything about returning any value.) */
2481 expand_null_return ()
2483 struct nesting *block = block_stack;
2486 if (output_bytecode)
2488 bc_emit_instruction (ret);
2492 /* Does any pending block have cleanups? */
2494 while (block && block->data.block.cleanups == 0)
2495 block = block->next;
2497 /* If yes, use a goto to return, since that runs cleanups. */
2499 expand_null_return_1 (last_insn, block != 0);
2502 /* Generate RTL to return from the current function, with value VAL. */
2505 expand_value_return (val)
2508 struct nesting *block = block_stack;
2509 rtx last_insn = get_last_insn ();
2510 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2512 /* Copy the value to the return location
2513 unless it's already there. */
2515 if (return_reg != val)
2517 #ifdef PROMOTE_FUNCTION_RETURN
2518 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2519 int unsignedp = TREE_UNSIGNED (type);
2520 enum machine_mode mode
2521 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2524 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2525 convert_move (return_reg, val, unsignedp);
2528 emit_move_insn (return_reg, val);
2530 if (GET_CODE (return_reg) == REG
2531 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2532 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2534 /* Does any pending block have cleanups? */
2536 while (block && block->data.block.cleanups == 0)
2537 block = block->next;
2539 /* If yes, use a goto to return, since that runs cleanups.
2540 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2542 expand_null_return_1 (last_insn, block != 0);
2545 /* Output a return with no value. If LAST_INSN is nonzero,
2546 pretend that the return takes place after LAST_INSN.
2547 If USE_GOTO is nonzero then don't use a return instruction;
2548 go to the return label instead. This causes any cleanups
2549 of pending blocks to be executed normally. */
2552 expand_null_return_1 (last_insn, use_goto)
2556 rtx end_label = cleanup_label ? cleanup_label : return_label;
2558 clear_pending_stack_adjust ();
2559 do_pending_stack_adjust ();
2562 /* PCC-struct return always uses an epilogue. */
2563 if (current_function_returns_pcc_struct || use_goto)
2566 end_label = return_label = gen_label_rtx ();
2567 expand_goto_internal (NULL_TREE, end_label, last_insn);
2571 /* Otherwise output a simple return-insn if one is available,
2572 unless it won't do the job. */
2574 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2576 emit_jump_insn (gen_return ());
2582 /* Otherwise jump to the epilogue. */
2583 expand_goto_internal (NULL_TREE, end_label, last_insn);
2586 /* Generate RTL to evaluate the expression RETVAL and return it
2587 from the current function. */
2590 expand_return (retval)
2593 /* If there are any cleanups to be performed, then they will
2594 be inserted following LAST_INSN. It is desirable
2595 that the last_insn, for such purposes, should be the
2596 last insn before computing the return value. Otherwise, cleanups
2597 which call functions can clobber the return value. */
2598 /* ??? rms: I think that is erroneous, because in C++ it would
2599 run destructors on variables that might be used in the subsequent
2600 computation of the return value. */
2602 register rtx val = 0;
2606 struct nesting *block;
2608 /* Bytecode returns are quite simple, just leave the result on the
2609 arithmetic stack. */
2610 if (output_bytecode)
2612 bc_expand_expr (retval);
2613 bc_emit_instruction (ret);
2617 /* If function wants no value, give it none. */
2618 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2620 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2622 expand_null_return ();
2626 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2627 /* This is not sufficient. We also need to watch for cleanups of the
2628 expression we are about to expand. Unfortunately, we cannot know
2629 if it has cleanups until we expand it, and we want to change how we
2630 expand it depending upon if we need cleanups. We can't win. */
2632 cleanups = any_pending_cleanups (1);
2637 if (TREE_CODE (retval) == RESULT_DECL)
2638 retval_rhs = retval;
2639 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2640 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2641 retval_rhs = TREE_OPERAND (retval, 1);
2642 else if (TREE_TYPE (retval) == void_type_node)
2643 /* Recognize tail-recursive call to void function. */
2644 retval_rhs = retval;
2646 retval_rhs = NULL_TREE;
2648 /* Only use `last_insn' if there are cleanups which must be run. */
2649 if (cleanups || cleanup_label != 0)
2650 last_insn = get_last_insn ();
2652 /* Distribute return down conditional expr if either of the sides
2653 may involve tail recursion (see test below). This enhances the number
2654 of tail recursions we see. Don't do this always since it can produce
2655 sub-optimal code in some cases and we distribute assignments into
2656 conditional expressions when it would help. */
2658 if (optimize && retval_rhs != 0
2659 && frame_offset == 0
2660 && TREE_CODE (retval_rhs) == COND_EXPR
2661 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2662 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2664 rtx label = gen_label_rtx ();
2667 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2668 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2669 DECL_RESULT (current_function_decl),
2670 TREE_OPERAND (retval_rhs, 1));
2671 TREE_SIDE_EFFECTS (expr) = 1;
2672 expand_return (expr);
2675 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2676 DECL_RESULT (current_function_decl),
2677 TREE_OPERAND (retval_rhs, 2));
2678 TREE_SIDE_EFFECTS (expr) = 1;
2679 expand_return (expr);
2683 /* For tail-recursive call to current function,
2684 just jump back to the beginning.
2685 It's unsafe if any auto variable in this function
2686 has its address taken; for simplicity,
2687 require stack frame to be empty. */
2688 if (optimize && retval_rhs != 0
2689 && frame_offset == 0
2690 && TREE_CODE (retval_rhs) == CALL_EXPR
2691 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2692 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2693 /* Finish checking validity, and if valid emit code
2694 to set the argument variables for the new call. */
2695 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2696 DECL_ARGUMENTS (current_function_decl)))
2698 if (tail_recursion_label == 0)
2700 tail_recursion_label = gen_label_rtx ();
2701 emit_label_after (tail_recursion_label,
2702 tail_recursion_reentry);
2705 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2710 /* This optimization is safe if there are local cleanups
2711 because expand_null_return takes care of them.
2712 ??? I think it should also be safe when there is a cleanup label,
2713 because expand_null_return takes care of them, too.
2714 Any reason why not? */
2715 if (HAVE_return && cleanup_label == 0
2716 && ! current_function_returns_pcc_struct
2717 && BRANCH_COST <= 1)
2719 /* If this is return x == y; then generate
2720 if (x == y) return 1; else return 0;
2721 if we can do it with explicit return insns and
2722 branches are cheap. */
2724 switch (TREE_CODE (retval_rhs))
2732 case TRUTH_ANDIF_EXPR:
2733 case TRUTH_ORIF_EXPR:
2734 case TRUTH_AND_EXPR:
2736 case TRUTH_NOT_EXPR:
2737 case TRUTH_XOR_EXPR:
2738 op0 = gen_label_rtx ();
2739 jumpifnot (retval_rhs, op0);
2740 expand_value_return (const1_rtx);
2742 expand_value_return (const0_rtx);
2746 #endif /* HAVE_return */
2748 /* If the result is an aggregate that is being returned in one (or more)
2749 registers, load the registers here. The compiler currently can't handle
2750 copying a BLKmode value into registers. We could put this code in a
2751 more general area (for use by everyone instead of just function
2752 call/return), but until this feature is generally usable it is kept here
2753 (and in expand_call). The value must go into a pseudo in case there
2754 are cleanups that will clobber the real return register. */
2757 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2758 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2760 int i, bitpos, xbitpos;
2761 int big_endian_correction = 0;
2762 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2763 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2764 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2765 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2766 rtx result_reg, src, dst;
2767 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2768 enum machine_mode tmpmode, result_reg_mode;
2770 /* Structures whose size is not a multiple of a word are aligned
2771 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2772 machine, this means we must skip the empty high order bytes when
2773 calculating the bit offset. */
2774 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2775 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2778 /* Copy the structure BITSIZE bits at a time. */
2779 for (bitpos = 0, xbitpos = big_endian_correction;
2780 bitpos < bytes * BITS_PER_UNIT;
2781 bitpos += bitsize, xbitpos += bitsize)
2783 /* We need a new destination pseudo each time xbitpos is
2784 on a word boundary and when xbitpos == big_endian_correction
2785 (the first time through). */
2786 if (xbitpos % BITS_PER_WORD == 0
2787 || xbitpos == big_endian_correction)
2789 /* Generate an appropriate register. */
2790 dst = gen_reg_rtx (word_mode);
2791 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2793 /* Clobber the destination before we move anything into it. */
2794 emit_insn (gen_rtx (CLOBBER, VOIDmode, dst));
2797 /* We need a new source operand each time bitpos is on a word
2799 if (bitpos % BITS_PER_WORD == 0)
2800 src = operand_subword_force (result_val,
2801 bitpos / BITS_PER_WORD,
2804 /* Use bitpos for the source extraction (left justified) and
2805 xbitpos for the destination store (right justified). */
2806 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2807 extract_bit_field (src, bitsize,
2808 bitpos % BITS_PER_WORD, 1,
2809 NULL_RTX, word_mode,
2811 bitsize / BITS_PER_UNIT,
2813 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2816 /* Find the smallest integer mode large enough to hold the
2817 entire structure and use that mode instead of BLKmode
2818 on the USE insn for the return register. */
2819 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2820 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2821 tmpmode != MAX_MACHINE_MODE;
2822 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2824 /* Have we found a large enough mode? */
2825 if (GET_MODE_SIZE (tmpmode) >= bytes)
2829 /* No suitable mode found. */
2830 if (tmpmode == MAX_MACHINE_MODE)
2833 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2835 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2836 result_reg_mode = word_mode;
2838 result_reg_mode = tmpmode;
2839 result_reg = gen_reg_rtx (result_reg_mode);
2841 /* Now that the value is in pseudos, copy it to the result reg(s). */
2844 for (i = 0; i < n_regs; i++)
2845 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2848 if (tmpmode != result_reg_mode)
2849 result_reg = gen_lowpart (tmpmode, result_reg);
2851 expand_value_return (result_reg);
2855 && TREE_TYPE (retval_rhs) != void_type_node
2856 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2858 /* Calculate the return value into a pseudo reg. */
2859 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2861 /* All temporaries have now been used. */
2863 /* Return the calculated value, doing cleanups first. */
2864 expand_value_return (val);
2868 /* No cleanups or no hard reg used;
2869 calculate value into hard return reg. */
2870 expand_expr (retval, const0_rtx, VOIDmode, 0);
2873 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2877 /* Return 1 if the end of the generated RTX is not a barrier.
2878 This means code already compiled can drop through. */
2881 drop_through_at_end_p ()
2883 rtx insn = get_last_insn ();
2884 while (insn && GET_CODE (insn) == NOTE)
2885 insn = PREV_INSN (insn);
2886 return insn && GET_CODE (insn) != BARRIER;
2889 /* Emit code to alter this function's formal parms for a tail-recursive call.
2890 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2891 FORMALS is the chain of decls of formals.
2892 Return 1 if this can be done;
2893 otherwise return 0 and do not emit any code. */
2896 tail_recursion_args (actuals, formals)
2897 tree actuals, formals;
2899 register tree a = actuals, f = formals;
2901 register rtx *argvec;
2903 /* Check that number and types of actuals are compatible
2904 with the formals. This is not always true in valid C code.
2905 Also check that no formal needs to be addressable
2906 and that all formals are scalars. */
2908 /* Also count the args. */
2910 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2912 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2914 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2917 if (a != 0 || f != 0)
2920 /* Compute all the actuals. */
2922 argvec = (rtx *) alloca (i * sizeof (rtx));
2924 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2925 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2927 /* Find which actual values refer to current values of previous formals.
2928 Copy each of them now, before any formal is changed. */
2930 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2934 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2935 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2936 { copy = 1; break; }
2938 argvec[i] = copy_to_reg (argvec[i]);
2941 /* Store the values of the actuals into the formals. */
2943 for (f = formals, a = actuals, i = 0; f;
2944 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2946 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2947 emit_move_insn (DECL_RTL (f), argvec[i]);
2949 convert_move (DECL_RTL (f), argvec[i],
2950 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2957 /* Generate the RTL code for entering a binding contour.
2958 The variables are declared one by one, by calls to `expand_decl'.
2960 EXIT_FLAG is nonzero if this construct should be visible to
2961 `exit_something'. */
2964 expand_start_bindings (exit_flag)
2967 struct nesting *thisblock = ALLOC_NESTING ();
2968 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2970 /* Make an entry on block_stack for the block we are entering. */
2972 thisblock->next = block_stack;
2973 thisblock->all = nesting_stack;
2974 thisblock->depth = ++nesting_depth;
2975 thisblock->data.block.stack_level = 0;
2976 thisblock->data.block.cleanups = 0;
2977 thisblock->data.block.function_call_count = 0;
2981 if (block_stack->data.block.cleanups == NULL_TREE
2982 && (block_stack->data.block.outer_cleanups == NULL_TREE
2983 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2984 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2986 thisblock->data.block.outer_cleanups
2987 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2988 block_stack->data.block.outer_cleanups);
2991 thisblock->data.block.outer_cleanups = 0;
2995 && !(block_stack->data.block.cleanups == NULL_TREE
2996 && block_stack->data.block.outer_cleanups == NULL_TREE))
2997 thisblock->data.block.outer_cleanups
2998 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2999 block_stack->data.block.outer_cleanups);
3001 thisblock->data.block.outer_cleanups = 0;
3003 thisblock->data.block.label_chain = 0;
3004 thisblock->data.block.innermost_stack_block = stack_block_stack;
3005 thisblock->data.block.first_insn = note;
3006 thisblock->data.block.block_start_count = ++block_start_count;
3007 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3008 block_stack = thisblock;
3009 nesting_stack = thisblock;
3011 if (!output_bytecode)
3013 /* Make a new level for allocating stack slots. */
3018 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3019 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3023 remember_end_note (block)
3024 register tree block;
3026 BLOCK_END_NOTE (block) = last_block_end_note;
3027 last_block_end_note = NULL_RTX;
3030 /* Generate RTL code to terminate a binding contour.
3031 VARS is the chain of VAR_DECL nodes
3032 for the variables bound in this contour.
3033 MARK_ENDS is nonzero if we should put a note at the beginning
3034 and end of this binding contour.
3036 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3037 (That is true automatically if the contour has a saved stack level.) */
3040 expand_end_bindings (vars, mark_ends, dont_jump_in)
3045 register struct nesting *thisblock = block_stack;
3048 if (output_bytecode)
3050 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
3055 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3056 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
3057 && ! DECL_IN_SYSTEM_HEADER (decl))
3058 warning_with_decl (decl, "unused variable `%s'");
3060 if (thisblock->exit_label)
3062 do_pending_stack_adjust ();
3063 emit_label (thisblock->exit_label);
3066 /* If necessary, make a handler for nonlocal gotos taking
3067 place in the function calls in this block. */
3068 if (function_call_count != thisblock->data.block.function_call_count
3070 /* Make handler for outermost block
3071 if there were any nonlocal gotos to this function. */
3072 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3073 /* Make handler for inner block if it has something
3074 special to do when you jump out of it. */
3075 : (thisblock->data.block.cleanups != 0
3076 || thisblock->data.block.stack_level != 0)))
3079 rtx afterward = gen_label_rtx ();
3080 rtx handler_label = gen_label_rtx ();
3081 rtx save_receiver = gen_reg_rtx (Pmode);
3084 /* Don't let jump_optimize delete the handler. */
3085 LABEL_PRESERVE_P (handler_label) = 1;
3087 /* Record the handler address in the stack slot for that purpose,
3088 during this block, saving and restoring the outer value. */
3089 if (thisblock->next != 0)
3091 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3094 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3095 insns = get_insns ();
3097 emit_insns_before (insns, thisblock->data.block.first_insn);
3101 emit_move_insn (nonlocal_goto_handler_slot,
3102 gen_rtx (LABEL_REF, Pmode, handler_label));
3103 insns = get_insns ();
3105 emit_insns_before (insns, thisblock->data.block.first_insn);
3107 /* Jump around the handler; it runs only when specially invoked. */
3108 emit_jump (afterward);
3109 emit_label (handler_label);
3111 #ifdef HAVE_nonlocal_goto
3112 if (! HAVE_nonlocal_goto)
3114 /* First adjust our frame pointer to its actual value. It was
3115 previously set to the start of the virtual area corresponding to
3116 the stacked variables when we branched here and now needs to be
3117 adjusted to the actual hardware fp value.
3119 Assignments are to virtual registers are converted by
3120 instantiate_virtual_regs into the corresponding assignment
3121 to the underlying register (fp in this case) that makes
3122 the original assignment true.
3123 So the following insn will actually be
3124 decrementing fp by STARTING_FRAME_OFFSET. */
3125 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3127 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3128 if (fixed_regs[ARG_POINTER_REGNUM])
3130 #ifdef ELIMINABLE_REGS
3131 /* If the argument pointer can be eliminated in favor of the
3132 frame pointer, we don't need to restore it. We assume here
3133 that if such an elimination is present, it can always be used.
3134 This is the case on all known machines; if we don't make this
3135 assumption, we do unnecessary saving on many machines. */
3136 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3139 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3140 if (elim_regs[i].from == ARG_POINTER_REGNUM
3141 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3144 if (i == sizeof elim_regs / sizeof elim_regs [0])
3147 /* Now restore our arg pointer from the address at which it
3148 was saved in our stack frame.
3149 If there hasn't be space allocated for it yet, make
3151 if (arg_pointer_save_area == 0)
3152 arg_pointer_save_area
3153 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3154 emit_move_insn (virtual_incoming_args_rtx,
3155 /* We need a pseudo here, or else
3156 instantiate_virtual_regs_1 complains. */
3157 copy_to_reg (arg_pointer_save_area));
3162 /* The handler expects the desired label address in the static chain
3163 register. It tests the address and does an appropriate jump
3164 to whatever label is desired. */
3165 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3166 /* Skip any labels we shouldn't be able to jump to from here. */
3167 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3169 rtx not_this = gen_label_rtx ();
3170 rtx this = gen_label_rtx ();
3171 do_jump_if_equal (static_chain_rtx,
3172 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3174 emit_jump (not_this);
3176 expand_goto (TREE_VALUE (link));
3177 emit_label (not_this);
3179 /* If label is not recognized, abort. */
3180 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3183 emit_label (afterward);
3186 /* Don't allow jumping into a block that has cleanups or a stack level. */
3188 || thisblock->data.block.stack_level != 0
3189 || thisblock->data.block.cleanups != 0)
3191 struct label_chain *chain;
3193 /* Any labels in this block are no longer valid to go to.
3194 Mark them to cause an error message. */
3195 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3197 DECL_TOO_LATE (chain->label) = 1;
3198 /* If any goto without a fixup came to this label,
3199 that must be an error, because gotos without fixups
3200 come from outside all saved stack-levels and all cleanups. */
3201 if (TREE_ADDRESSABLE (chain->label))
3202 error_with_decl (chain->label,
3203 "label `%s' used before containing binding contour");
3207 /* Restore stack level in effect before the block
3208 (only if variable-size objects allocated). */
3209 /* Perform any cleanups associated with the block. */
3211 if (thisblock->data.block.stack_level != 0
3212 || thisblock->data.block.cleanups != 0)
3214 /* Only clean up here if this point can actually be reached. */
3215 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3217 /* Don't let cleanups affect ({...}) constructs. */
3218 int old_expr_stmts_for_value = expr_stmts_for_value;
3219 rtx old_last_expr_value = last_expr_value;
3220 tree old_last_expr_type = last_expr_type;
3221 expr_stmts_for_value = 0;
3223 /* Do the cleanups. */
3224 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3226 do_pending_stack_adjust ();
3228 expr_stmts_for_value = old_expr_stmts_for_value;
3229 last_expr_value = old_last_expr_value;
3230 last_expr_type = old_last_expr_type;
3232 /* Restore the stack level. */
3234 if (reachable && thisblock->data.block.stack_level != 0)
3236 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3237 thisblock->data.block.stack_level, NULL_RTX);
3238 if (nonlocal_goto_handler_slot != 0)
3239 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3243 /* Any gotos out of this block must also do these things.
3244 Also report any gotos with fixups that came to labels in this
3246 fixup_gotos (thisblock,
3247 thisblock->data.block.stack_level,
3248 thisblock->data.block.cleanups,
3249 thisblock->data.block.first_insn,
3253 /* Mark the beginning and end of the scope if requested.
3254 We do this now, after running cleanups on the variables
3255 just going out of scope, so they are in scope for their cleanups. */
3258 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3260 /* Get rid of the beginning-mark if we don't make an end-mark. */
3261 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3263 /* If doing stupid register allocation, make sure lives of all
3264 register variables declared here extend thru end of scope. */
3267 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3269 rtx rtl = DECL_RTL (decl);
3270 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3274 /* Restore block_stack level for containing block. */
3276 stack_block_stack = thisblock->data.block.innermost_stack_block;
3277 POPSTACK (block_stack);
3279 /* Pop the stack slot nesting and free any slots at this level. */
3284 /* End a binding contour.
3285 VARS is the chain of VAR_DECL nodes for the variables bound
3286 in this contour. MARK_ENDS is nonzer if we should put a note
3287 at the beginning and end of this binding contour.
3288 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3292 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3297 struct nesting *thisbind = nesting_stack;
3301 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3302 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3303 warning_with_decl (decl, "unused variable `%s'");
3305 if (thisbind->exit_label)
3306 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3308 /* Pop block/bindings off stack */
3309 POPSTACK (block_stack);
3312 /* Generate RTL for the automatic variable declaration DECL.
3313 (Other kinds of declarations are simply ignored if seen here.) */
3319 struct nesting *thisblock = block_stack;
3322 if (output_bytecode)
3324 bc_expand_decl (decl, 0);
3328 type = TREE_TYPE (decl);
3330 /* Only automatic variables need any expansion done.
3331 Static and external variables, and external functions,
3332 will be handled by `assemble_variable' (called from finish_decl).
3333 TYPE_DECL and CONST_DECL require nothing.
3334 PARM_DECLs are handled in `assign_parms'. */
3336 if (TREE_CODE (decl) != VAR_DECL)
3338 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3341 /* Create the RTL representation for the variable. */
3343 if (type == error_mark_node)
3344 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3345 else if (DECL_SIZE (decl) == 0)
3346 /* Variable with incomplete type. */
3348 if (DECL_INITIAL (decl) == 0)
3349 /* Error message was already done; now avoid a crash. */
3350 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3352 /* An initializer is going to decide the size of this array.
3353 Until we know the size, represent its address with a reg. */
3354 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3355 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3357 else if (DECL_MODE (decl) != BLKmode
3358 /* If -ffloat-store, don't put explicit float vars
3360 && !(flag_float_store
3361 && TREE_CODE (type) == REAL_TYPE)
3362 && ! TREE_THIS_VOLATILE (decl)
3363 && ! TREE_ADDRESSABLE (decl)
3364 && (DECL_REGISTER (decl) || ! obey_regdecls))
3366 /* Automatic variable that can go in a register. */
3367 int unsignedp = TREE_UNSIGNED (type);
3368 enum machine_mode reg_mode
3369 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3371 if (TREE_CODE (type) == COMPLEX_TYPE)
3373 rtx realpart, imagpart;
3374 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3376 /* For a complex type variable, make a CONCAT of two pseudos
3377 so that the real and imaginary parts
3378 can be allocated separately. */
3379 realpart = gen_reg_rtx (partmode);
3380 REG_USERVAR_P (realpart) = 1;
3381 imagpart = gen_reg_rtx (partmode);
3382 REG_USERVAR_P (imagpart) = 1;
3383 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3387 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3388 if (TREE_CODE (type) == POINTER_TYPE)
3389 mark_reg_pointer (DECL_RTL (decl));
3390 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3393 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3395 /* Variable of fixed size that goes on the stack. */
3399 /* If we previously made RTL for this decl, it must be an array
3400 whose size was determined by the initializer.
3401 The old address was a register; set that register now
3402 to the proper address. */
3403 if (DECL_RTL (decl) != 0)
3405 if (GET_CODE (DECL_RTL (decl)) != MEM
3406 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3408 oldaddr = XEXP (DECL_RTL (decl), 0);
3412 = assign_stack_temp (DECL_MODE (decl),
3413 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3414 + BITS_PER_UNIT - 1)
3417 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3419 /* Set alignment we actually gave this decl. */
3420 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3421 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3425 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3426 if (addr != oldaddr)
3427 emit_move_insn (oldaddr, addr);
3430 /* If this is a memory ref that contains aggregate components,
3431 mark it as such for cse and loop optimize. */
3432 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3434 /* If this is in memory because of -ffloat-store,
3435 set the volatile bit, to prevent optimizations from
3436 undoing the effects. */
3437 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3438 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3442 /* Dynamic-size object: must push space on the stack. */
3446 /* Record the stack pointer on entry to block, if have
3447 not already done so. */
3448 if (thisblock->data.block.stack_level == 0)
3450 do_pending_stack_adjust ();
3451 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3452 &thisblock->data.block.stack_level,
3453 thisblock->data.block.first_insn);
3454 stack_block_stack = thisblock;
3457 /* Compute the variable's size, in bytes. */
3458 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3460 size_int (BITS_PER_UNIT)),
3461 NULL_RTX, VOIDmode, 0);
3464 /* Allocate space on the stack for the variable. */
3465 address = allocate_dynamic_stack_space (size, NULL_RTX,
3468 /* Reference the variable indirect through that rtx. */
3469 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3471 /* If this is a memory ref that contains aggregate components,
3472 mark it as such for cse and loop optimize. */
3473 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3475 /* Indicate the alignment we actually gave this variable. */
3476 #ifdef STACK_BOUNDARY
3477 DECL_ALIGN (decl) = STACK_BOUNDARY;
3479 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3483 if (TREE_THIS_VOLATILE (decl))
3484 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3485 #if 0 /* A variable is not necessarily unchanging
3486 just because it is const. RTX_UNCHANGING_P
3487 means no change in the function,
3488 not merely no change in the variable's scope.
3489 It is correct to set RTX_UNCHANGING_P if the variable's scope
3490 is the whole function. There's no convenient way to test that. */
3491 if (TREE_READONLY (decl))
3492 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3495 /* If doing stupid register allocation, make sure life of any
3496 register variable starts here, at the start of its scope. */
3499 use_variable (DECL_RTL (decl));
3503 /* Generate code for the automatic variable declaration DECL. For
3504 most variables this just means we give it a stack offset. The
3505 compiler sometimes emits cleanups without variables and we will
3506 have to deal with those too. */
3509 bc_expand_decl (decl, cleanup)
3517 /* A cleanup with no variable. */
3524 /* Only auto variables need any work. */
3525 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3528 type = TREE_TYPE (decl);
3530 if (type == error_mark_node)
3531 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3533 else if (DECL_SIZE (decl) == 0)
3535 /* Variable with incomplete type. The stack offset herein will be
3536 fixed later in expand_decl_init (). */
3537 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3539 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3541 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3545 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3548 /* Emit code to perform the initialization of a declaration DECL. */
3551 expand_decl_init (decl)
3554 int was_used = TREE_USED (decl);
3556 if (output_bytecode)
3558 bc_expand_decl_init (decl);
3562 /* If this is a CONST_DECL, we don't have to generate any code, but
3563 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3564 to be set while in the obstack containing the constant. If we don't
3565 do this, we can lose if we have functions nested three deep and the middle
3566 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3567 the innermost function is the first to expand that STRING_CST. */
3568 if (TREE_CODE (decl) == CONST_DECL)
3570 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3571 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3572 EXPAND_INITIALIZER);
3576 if (TREE_STATIC (decl))
3579 /* Compute and store the initial value now. */
3581 if (DECL_INITIAL (decl) == error_mark_node)
3583 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3584 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3585 || code == POINTER_TYPE)
3586 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3590 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3592 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3593 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3597 /* Don't let the initialization count as "using" the variable. */
3598 TREE_USED (decl) = was_used;
3600 /* Free any temporaries we made while initializing the decl. */
3601 preserve_temp_slots (NULL_RTX);
3605 /* Expand initialization for variable-sized types. Allocate array
3606 using newlocalSI and set local variable, which is a pointer to the
3610 bc_expand_variable_local_init (decl)
3613 /* Evaluate size expression and coerce to SI */
3614 bc_expand_expr (DECL_SIZE (decl));
3616 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3617 no coercion is necessary (?) */
3619 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3620 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3622 /* Emit code to allocate array */
3623 bc_emit_instruction (newlocalSI);
3625 /* Store array pointer in local variable. This is the only instance
3626 where we actually want the address of the pointer to the
3627 variable-size block, rather than the pointer itself. We avoid
3628 using expand_address() since that would cause the pointer to be
3629 pushed rather than its address. Hence the hard-coded reference;
3630 notice also that the variable is always local (no global
3631 variable-size type variables). */
3633 bc_load_localaddr (DECL_RTL (decl));
3634 bc_emit_instruction (storeP);
3638 /* Emit code to initialize a declaration. */
3641 bc_expand_decl_init (decl)
3644 int org_stack_depth;
3646 /* Statical initializers are handled elsewhere */
3648 if (TREE_STATIC (decl))
3651 /* Memory original stack depth */
3652 org_stack_depth = stack_depth;
3654 /* If the type is variable-size, we first create its space (we ASSUME
3655 it CAN'T be static). We do this regardless of whether there's an
3656 initializer assignment or not. */
3658 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3659 bc_expand_variable_local_init (decl);
3661 /* Expand initializer assignment */
3662 if (DECL_INITIAL (decl) == error_mark_node)
3664 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3666 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3667 || code == POINTER_TYPE)
3669 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3671 else if (DECL_INITIAL (decl))
3672 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3674 /* Restore stack depth */
3675 if (org_stack_depth > stack_depth)
3678 bc_adjust_stack (stack_depth - org_stack_depth);
3682 /* CLEANUP is an expression to be executed at exit from this binding contour;
3683 for example, in C++, it might call the destructor for this variable.
3685 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3686 either before or after calling `expand_decl_cleanup' but before compiling
3687 any subsequent expressions. This is because CLEANUP may be expanded
3688 more than once, on different branches of execution.
3689 For the same reason, CLEANUP may not contain a CALL_EXPR
3690 except as its topmost node--else `preexpand_calls' would get confused.
3692 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3693 that is not associated with any particular variable. */
3696 expand_decl_cleanup (decl, cleanup)
3699 struct nesting *thisblock = block_stack;
3701 /* Error if we are not in any block. */
3705 /* Record the cleanup if there is one. */
3709 thisblock->data.block.cleanups
3710 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3711 /* If this block has a cleanup, it belongs in stack_block_stack. */
3712 stack_block_stack = thisblock;
3713 (*interim_eh_hook) (NULL_TREE);
3718 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3719 DECL_ELTS is the list of elements that belong to DECL's type.
3720 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3723 expand_anon_union_decl (decl, cleanup, decl_elts)
3724 tree decl, cleanup, decl_elts;
3726 struct nesting *thisblock = block_stack;
3730 expand_decl_cleanup (decl, cleanup);
3731 x = DECL_RTL (decl);
3735 tree decl_elt = TREE_VALUE (decl_elts);
3736 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3737 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3739 /* Propagate the union's alignment to the elements. */
3740 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3742 /* If the element has BLKmode and the union doesn't, the union is
3743 aligned such that the element doesn't need to have BLKmode, so
3744 change the element's mode to the appropriate one for its size. */
3745 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3746 DECL_MODE (decl_elt) = mode
3747 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3750 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3751 instead create a new MEM rtx with the proper mode. */
3752 if (GET_CODE (x) == MEM)
3754 if (mode == GET_MODE (x))
3755 DECL_RTL (decl_elt) = x;
3758 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3759 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3760 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3763 else if (GET_CODE (x) == REG)
3765 if (mode == GET_MODE (x))
3766 DECL_RTL (decl_elt) = x;
3768 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3773 /* Record the cleanup if there is one. */
3776 thisblock->data.block.cleanups
3777 = temp_tree_cons (decl_elt, cleanup_elt,
3778 thisblock->data.block.cleanups);
3780 decl_elts = TREE_CHAIN (decl_elts);
3784 /* Expand a list of cleanups LIST.
3785 Elements may be expressions or may be nested lists.
3787 If DONT_DO is nonnull, then any list-element
3788 whose TREE_PURPOSE matches DONT_DO is omitted.
3789 This is sometimes used to avoid a cleanup associated with
3790 a value that is being returned out of the scope.
3792 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3793 goto and handle protection regions specially in that case.
3795 If REACHABLE, we emit code, otherwise just inform the exception handling
3796 code about this finalization. */
3799 expand_cleanups (list, dont_do, in_fixup, reachable)
3806 for (tail = list; tail; tail = TREE_CHAIN (tail))
3807 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3809 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3810 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3814 (*interim_eh_hook) (TREE_VALUE (tail));
3818 /* Cleanups may be run multiple times. For example,
3819 when exiting a binding contour, we expand the
3820 cleanups associated with that contour. When a goto
3821 within that binding contour has a target outside that
3822 contour, it will expand all cleanups from its scope to
3823 the target. Though the cleanups are expanded multiple
3824 times, the control paths are non-overlapping so the
3825 cleanups will not be executed twice. */
3826 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3833 /* Move all cleanups from the current block_stack
3834 to the containing block_stack, where they are assumed to
3835 have been created. If anything can cause a temporary to
3836 be created, but not expanded for more than one level of
3837 block_stacks, then this code will have to change. */
3842 struct nesting *block = block_stack;
3843 struct nesting *outer = block->next;
3845 outer->data.block.cleanups
3846 = chainon (block->data.block.cleanups,
3847 outer->data.block.cleanups);
3848 block->data.block.cleanups = 0;
3852 last_cleanup_this_contour ()
3854 if (block_stack == 0)
3857 return block_stack->data.block.cleanups;
3860 /* Return 1 if there are any pending cleanups at this point.
3861 If THIS_CONTOUR is nonzero, check the current contour as well.
3862 Otherwise, look only at the contours that enclose this one. */
3865 any_pending_cleanups (this_contour)
3868 struct nesting *block;
3870 if (block_stack == 0)
3873 if (this_contour && block_stack->data.block.cleanups != NULL)
3875 if (block_stack->data.block.cleanups == 0
3876 && (block_stack->data.block.outer_cleanups == 0
3878 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3883 for (block = block_stack->next; block; block = block->next)
3884 if (block->data.block.cleanups != 0)
3890 /* Enter a case (Pascal) or switch (C) statement.
3891 Push a block onto case_stack and nesting_stack
3892 to accumulate the case-labels that are seen
3893 and to record the labels generated for the statement.
3895 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3896 Otherwise, this construct is transparent for `exit_something'.
3898 EXPR is the index-expression to be dispatched on.
3899 TYPE is its nominal type. We could simply convert EXPR to this type,
3900 but instead we take short cuts. */
3903 expand_start_case (exit_flag, expr, type, printname)
3909 register struct nesting *thiscase = ALLOC_NESTING ();
3911 /* Make an entry on case_stack for the case we are entering. */
3913 thiscase->next = case_stack;
3914 thiscase->all = nesting_stack;
3915 thiscase->depth = ++nesting_depth;
3916 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3917 thiscase->data.case_stmt.case_list = 0;
3918 thiscase->data.case_stmt.index_expr = expr;
3919 thiscase->data.case_stmt.nominal_type = type;
3920 thiscase->data.case_stmt.default_label = 0;
3921 thiscase->data.case_stmt.num_ranges = 0;
3922 thiscase->data.case_stmt.printname = printname;
3923 thiscase->data.case_stmt.seenlabel = 0;
3924 case_stack = thiscase;
3925 nesting_stack = thiscase;
3927 if (output_bytecode)
3929 bc_expand_start_case (thiscase, expr, type, printname);
3933 do_pending_stack_adjust ();
3935 /* Make sure case_stmt.start points to something that won't
3936 need any transformation before expand_end_case. */
3937 if (GET_CODE (get_last_insn ()) != NOTE)
3938 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3940 thiscase->data.case_stmt.start = get_last_insn ();
3944 /* Enter a case statement. It is assumed that the caller has pushed
3945 the current context onto the case stack. */
3948 bc_expand_start_case (thiscase, expr, type, printname)
3949 struct nesting *thiscase;
3954 bc_expand_expr (expr);
3955 bc_expand_conversion (TREE_TYPE (expr), type);
3957 /* For cases, the skip is a place we jump to that's emitted after
3958 the size of the jump table is known. */
3960 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3961 bc_emit_bytecode (jump);
3962 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3964 #ifdef DEBUG_PRINT_CODE
3965 fputc ('\n', stderr);
3970 /* Start a "dummy case statement" within which case labels are invalid
3971 and are not connected to any larger real case statement.
3972 This can be used if you don't want to let a case statement jump
3973 into the middle of certain kinds of constructs. */
3976 expand_start_case_dummy ()
3978 register struct nesting *thiscase = ALLOC_NESTING ();
3980 /* Make an entry on case_stack for the dummy. */
3982 thiscase->next = case_stack;
3983 thiscase->all = nesting_stack;
3984 thiscase->depth = ++nesting_depth;
3985 thiscase->exit_label = 0;
3986 thiscase->data.case_stmt.case_list = 0;
3987 thiscase->data.case_stmt.start = 0;
3988 thiscase->data.case_stmt.nominal_type = 0;
3989 thiscase->data.case_stmt.default_label = 0;
3990 thiscase->data.case_stmt.num_ranges = 0;
3991 case_stack = thiscase;
3992 nesting_stack = thiscase;
3995 /* End a dummy case statement. */
3998 expand_end_case_dummy ()
4000 POPSTACK (case_stack);
4003 /* Return the data type of the index-expression
4004 of the innermost case statement, or null if none. */
4007 case_index_expr_type ()
4010 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4014 /* Accumulate one case or default label inside a case or switch statement.
4015 VALUE is the value of the case (a null pointer, for a default label).
4016 The function CONVERTER, when applied to arguments T and V,
4017 converts the value V to the type T.
4019 If not currently inside a case or switch statement, return 1 and do
4020 nothing. The caller will print a language-specific error message.
4021 If VALUE is a duplicate or overlaps, return 2 and do nothing
4022 except store the (first) duplicate node in *DUPLICATE.
4023 If VALUE is out of range, return 3 and do nothing.
4024 If we are jumping into the scope of a cleaup or var-sized array, return 5.
4025 Return 0 on success.
4027 Extended to handle range statements. */
4030 pushcase (value, converter, label, duplicate)
4031 register tree value;
4032 tree (*converter) PROTO((tree, tree));
4033 register tree label;
4036 register struct case_node **l;
4037 register struct case_node *n;
4041 if (output_bytecode)
4042 return bc_pushcase (value, label);
4044 /* Fail if not inside a real case statement. */
4045 if (! (case_stack && case_stack->data.case_stmt.start))
4048 if (stack_block_stack
4049 && stack_block_stack->depth > case_stack->depth)
4052 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4053 nominal_type = case_stack->data.case_stmt.nominal_type;
4055 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4056 if (index_type == error_mark_node)
4059 /* Convert VALUE to the type in which the comparisons are nominally done. */
4061 value = (*converter) (nominal_type, value);
4063 /* If this is the first label, warn if any insns have been emitted. */
4064 if (case_stack->data.case_stmt.seenlabel == 0)
4067 for (insn = case_stack->data.case_stmt.start;
4069 insn = NEXT_INSN (insn))
4071 if (GET_CODE (insn) == CODE_LABEL)
4073 if (GET_CODE (insn) != NOTE
4074 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4076 warning ("unreachable code at beginning of %s",
4077 case_stack->data.case_stmt.printname);
4082 case_stack->data.case_stmt.seenlabel = 1;
4084 /* Fail if this value is out of range for the actual type of the index
4085 (which may be narrower than NOMINAL_TYPE). */
4086 if (value != 0 && ! int_fits_type_p (value, index_type))
4089 /* Fail if this is a duplicate or overlaps another entry. */
4092 if (case_stack->data.case_stmt.default_label != 0)
4094 *duplicate = case_stack->data.case_stmt.default_label;
4097 case_stack->data.case_stmt.default_label = label;
4101 /* Find the elt in the chain before which to insert the new value,
4102 to keep the chain sorted in increasing order.
4103 But report an error if this element is a duplicate. */
4104 for (l = &case_stack->data.case_stmt.case_list;
4105 /* Keep going past elements distinctly less than VALUE. */
4106 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4111 /* Element we will insert before must be distinctly greater;
4112 overlap means error. */
4113 if (! tree_int_cst_lt (value, (*l)->low))
4115 *duplicate = (*l)->code_label;
4120 /* Add this label to the chain, and succeed.
4121 Copy VALUE so it is on temporary rather than momentary
4122 obstack and will thus survive till the end of the case statement. */
4123 n = (struct case_node *) oballoc (sizeof (struct case_node));
4126 n->high = n->low = copy_node (value);
4127 n->code_label = label;
4131 expand_label (label);
4135 /* Like pushcase but this case applies to all values
4136 between VALUE1 and VALUE2 (inclusive).
4137 The return value is the same as that of pushcase
4138 but there is one additional error code:
4139 4 means the specified range was empty. */
4142 pushcase_range (value1, value2, converter, label, duplicate)
4143 register tree value1, value2;
4144 tree (*converter) PROTO((tree, tree));
4145 register tree label;
4148 register struct case_node **l;
4149 register struct case_node *n;
4153 /* Fail if not inside a real case statement. */
4154 if (! (case_stack && case_stack->data.case_stmt.start))
4157 if (stack_block_stack
4158 && stack_block_stack->depth > case_stack->depth)
4161 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4162 nominal_type = case_stack->data.case_stmt.nominal_type;
4164 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4165 if (index_type == error_mark_node)
4168 /* If this is the first label, warn if any insns have been emitted. */
4169 if (case_stack->data.case_stmt.seenlabel == 0)
4172 for (insn = case_stack->data.case_stmt.start;
4174 insn = NEXT_INSN (insn))
4176 if (GET_CODE (insn) == CODE_LABEL)
4178 if (GET_CODE (insn) != NOTE
4179 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4181 warning ("unreachable code at beginning of %s",
4182 case_stack->data.case_stmt.printname);
4187 case_stack->data.case_stmt.seenlabel = 1;
4189 /* Convert VALUEs to type in which the comparisons are nominally done. */
4190 if (value1 == 0) /* Negative infinity. */
4191 value1 = TYPE_MIN_VALUE(index_type);
4192 value1 = (*converter) (nominal_type, value1);
4194 if (value2 == 0) /* Positive infinity. */
4195 value2 = TYPE_MAX_VALUE(index_type);
4196 value2 = (*converter) (nominal_type, value2);
4198 /* Fail if these values are out of range. */
4199 if (! int_fits_type_p (value1, index_type))
4202 if (! int_fits_type_p (value2, index_type))
4205 /* Fail if the range is empty. */
4206 if (tree_int_cst_lt (value2, value1))
4209 /* If the bounds are equal, turn this into the one-value case. */
4210 if (tree_int_cst_equal (value1, value2))
4211 return pushcase (value1, converter, label, duplicate);
4213 /* Find the elt in the chain before which to insert the new value,
4214 to keep the chain sorted in increasing order.
4215 But report an error if this element is a duplicate. */
4216 for (l = &case_stack->data.case_stmt.case_list;
4217 /* Keep going past elements distinctly less than this range. */
4218 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4223 /* Element we will insert before must be distinctly greater;
4224 overlap means error. */
4225 if (! tree_int_cst_lt (value2, (*l)->low))
4227 *duplicate = (*l)->code_label;
4232 /* Add this label to the chain, and succeed.
4233 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4234 obstack and will thus survive till the end of the case statement. */
4236 n = (struct case_node *) oballoc (sizeof (struct case_node));
4239 n->low = copy_node (value1);
4240 n->high = copy_node (value2);
4241 n->code_label = label;
4244 expand_label (label);
4246 case_stack->data.case_stmt.num_ranges++;
4252 /* Accumulate one case or default label; VALUE is the value of the
4253 case, or nil for a default label. If not currently inside a case,
4254 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4255 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4256 Return 0 on success. This function is a leftover from the earlier
4257 bytecode compiler, which was based on gcc 1.37. It should be
4258 merged into pushcase. */
4261 bc_pushcase (value, label)
4265 struct nesting *thiscase = case_stack;
4266 struct case_node *case_label, *new_label;
4271 /* Fail if duplicate, overlap, or out of type range. */
4274 value = convert (thiscase->data.case_stmt.nominal_type, value);
4275 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4278 for (case_label = thiscase->data.case_stmt.case_list;
4279 case_label->left; case_label = case_label->left)
4280 if (! tree_int_cst_lt (case_label->left->high, value))
4283 if (case_label != thiscase->data.case_stmt.case_list
4284 && ! tree_int_cst_lt (case_label->high, value)
4285 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4288 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4289 new_label->low = new_label->high = copy_node (value);
4290 new_label->code_label = label;
4291 new_label->left = case_label->left;
4293 case_label->left = new_label;
4294 thiscase->data.case_stmt.num_ranges++;
4298 if (thiscase->data.case_stmt.default_label)
4300 thiscase->data.case_stmt.default_label = label;
4303 expand_label (label);
4307 /* Returns the number of possible values of TYPE.
4308 Returns -1 if the number is unknown or variable.
4309 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4310 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4311 do not increase monotonically (there may be duplicates);
4312 to 1 if the values increase monotonically, but not always by 1;
4313 otherwise sets it to 0. */
4316 all_cases_count (type, spareness)
4320 HOST_WIDE_INT count, count_high = 0;
4323 switch (TREE_CODE (type))
4330 count = 1 << BITS_PER_UNIT;
4334 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4335 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4340 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4341 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4342 but with overflow checking. */
4343 tree mint = TYPE_MIN_VALUE (type);
4344 tree maxt = TYPE_MAX_VALUE (type);
4345 HOST_WIDE_INT lo, hi;
4346 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4348 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4350 add_double (lo, hi, 1, 0, &lo, &hi);
4351 if (hi != 0 || lo < 0)
4358 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4360 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4361 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4362 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4363 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4367 if (*spareness == 1)
4369 tree prev = TREE_VALUE (TYPE_VALUES (type));
4370 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4372 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4377 prev = TREE_VALUE (t);
4386 #define BITARRAY_TEST(ARRAY, INDEX) \
4387 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4388 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4389 #define BITARRAY_SET(ARRAY, INDEX) \
4390 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4391 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4393 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4394 with the case values we have seen, assuming the case expression
4396 SPARSENESS is as determined by all_cases_count.
4398 The time needed is proportional to COUNT, unless
4399 SPARSENESS is 2, in which case quadratic time is needed. */
4402 mark_seen_cases (type, cases_seen, count, sparseness)
4404 unsigned char *cases_seen;
4410 tree next_node_to_try = NULL_TREE;
4411 long next_node_offset = 0;
4413 register struct case_node *n;
4414 tree val = make_node (INTEGER_CST);
4415 TREE_TYPE (val) = type;
4416 for (n = case_stack->data.case_stmt.case_list; n;
4419 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4420 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4421 while ( ! tree_int_cst_lt (n->high, val))
4423 /* Calculate (into xlo) the "offset" of the integer (val).
4424 The element with lowest value has offset 0, the next smallest
4425 element has offset 1, etc. */
4427 HOST_WIDE_INT xlo, xhi;
4429 if (sparseness == 2)
4431 /* This less efficient loop is only needed to handle
4432 duplicate case values (multiple enum constants
4433 with the same value). */
4434 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4435 t = TREE_CHAIN (t), xlo++)
4437 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4438 BITARRAY_SET (cases_seen, xlo);
4443 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4445 /* The TYPE_VALUES will be in increasing order, so
4446 starting searching where we last ended. */
4447 t = next_node_to_try;
4448 xlo = next_node_offset;
4454 t = TYPE_VALUES (type);
4457 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4459 next_node_to_try = TREE_CHAIN (t);
4460 next_node_offset = xlo + 1;
4465 if (t == next_node_to_try)
4471 t = TYPE_MIN_VALUE (type);
4473 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4477 add_double (xlo, xhi,
4478 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4482 if (xhi == 0 && xlo >= 0 && xlo < count)
4483 BITARRAY_SET (cases_seen, xlo);
4485 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4487 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4492 /* Called when the index of a switch statement is an enumerated type
4493 and there is no default label.
4495 Checks that all enumeration literals are covered by the case
4496 expressions of a switch. Also, warn if there are any extra
4497 switch cases that are *not* elements of the enumerated type.
4499 If all enumeration literals were covered by the case expressions,
4500 turn one of the expressions into the default expression since it should
4501 not be possible to fall through such a switch. */
4504 check_for_full_enumeration_handling (type)
4507 register struct case_node *n;
4508 register struct case_node **l;
4509 register tree chain;
4512 /* True iff the selector type is a numbered set mode. */
4515 /* The number of possible selector values. */
4518 /* For each possible selector value. a one iff it has been matched
4519 by a case value alternative. */
4520 unsigned char *cases_seen;
4522 /* The allocated size of cases_seen, in chars. */
4526 if (output_bytecode)
4528 bc_check_for_full_enumeration_handling (type);
4535 size = all_cases_count (type, &sparseness);
4536 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4538 if (size > 0 && size < 600000
4539 /* We deliberately use malloc here - not xmalloc. */
4540 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4543 tree v = TYPE_VALUES (type);
4544 bzero (cases_seen, bytes_needed);
4546 /* The time complexity of this code is normally O(N), where
4547 N being the number of members in the enumerated type.
4548 However, if type is a ENUMERAL_TYPE whose values do not
4549 increase monotonically, quadratic time may be needed. */
4551 mark_seen_cases (type, cases_seen, size, sparseness);
4553 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4555 if (BITARRAY_TEST(cases_seen, i) == 0)
4556 warning ("enumeration value `%s' not handled in switch",
4557 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4563 /* Now we go the other way around; we warn if there are case
4564 expressions that don't correspond to enumerators. This can
4565 occur since C and C++ don't enforce type-checking of
4566 assignments to enumeration variables. */
4569 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4571 for (chain = TYPE_VALUES (type);
4572 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4573 chain = TREE_CHAIN (chain))
4578 if (TYPE_NAME (type) == 0)
4579 warning ("case value `%d' not in enumerated type",
4580 TREE_INT_CST_LOW (n->low));
4582 warning ("case value `%d' not in enumerated type `%s'",
4583 TREE_INT_CST_LOW (n->low),
4584 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4587 : DECL_NAME (TYPE_NAME (type))));
4589 if (!tree_int_cst_equal (n->low, n->high))
4591 for (chain = TYPE_VALUES (type);
4592 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4593 chain = TREE_CHAIN (chain))
4598 if (TYPE_NAME (type) == 0)
4599 warning ("case value `%d' not in enumerated type",
4600 TREE_INT_CST_LOW (n->high));
4602 warning ("case value `%d' not in enumerated type `%s'",
4603 TREE_INT_CST_LOW (n->high),
4604 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4607 : DECL_NAME (TYPE_NAME (type))));
4613 /* ??? This optimization is disabled because it causes valid programs to
4614 fail. ANSI C does not guarantee that an expression with enum type
4615 will have a value that is the same as one of the enumeration literals. */
4617 /* If all values were found as case labels, make one of them the default
4618 label. Thus, this switch will never fall through. We arbitrarily pick
4619 the last one to make the default since this is likely the most
4620 efficient choice. */
4624 for (l = &case_stack->data.case_stmt.case_list;
4629 case_stack->data.case_stmt.default_label = (*l)->code_label;
4636 /* Check that all enumeration literals are covered by the case
4637 expressions of a switch. Also warn if there are any cases
4638 that are not elements of the enumerated type. */
4641 bc_check_for_full_enumeration_handling (type)
4644 struct nesting *thiscase = case_stack;
4645 struct case_node *c;
4648 /* Check for enums not handled. */
4649 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4651 for (c = thiscase->data.case_stmt.case_list->left;
4652 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4655 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4656 warning ("enumerated value `%s' not handled in switch",
4657 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4660 /* Check for cases not in the enumeration. */
4661 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4663 for (e = TYPE_VALUES (type);
4664 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4668 warning ("case value `%d' not in enumerated type `%s'",
4669 TREE_INT_CST_LOW (c->low),
4670 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4672 : DECL_NAME (TYPE_NAME (type))));
4676 /* Terminate a case (Pascal) or switch (C) statement
4677 in which ORIG_INDEX is the expression to be tested.
4678 Generate the code to test it and jump to the right place. */
4681 expand_end_case (orig_index)
4684 tree minval, maxval, range, orig_minval;
4685 rtx default_label = 0;
4686 register struct case_node *n;
4694 register struct nesting *thiscase = case_stack;
4695 tree index_expr, index_type;
4698 if (output_bytecode)
4700 bc_expand_end_case (orig_index);
4704 table_label = gen_label_rtx ();
4705 index_expr = thiscase->data.case_stmt.index_expr;
4706 index_type = TREE_TYPE (index_expr);
4707 unsignedp = TREE_UNSIGNED (index_type);
4709 do_pending_stack_adjust ();
4711 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4712 if (index_type != error_mark_node)
4714 /* If switch expression was an enumerated type, check that all
4715 enumeration literals are covered by the cases.
4716 No sense trying this if there's a default case, however. */
4718 if (!thiscase->data.case_stmt.default_label
4719 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4720 && TREE_CODE (index_expr) != INTEGER_CST)
4721 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4723 /* If this is the first label, warn if any insns have been emitted. */
4724 if (thiscase->data.case_stmt.seenlabel == 0)
4727 for (insn = get_last_insn ();
4728 insn != case_stack->data.case_stmt.start;
4729 insn = PREV_INSN (insn))
4730 if (GET_CODE (insn) != NOTE
4731 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4733 warning ("unreachable code at beginning of %s",
4734 case_stack->data.case_stmt.printname);
4739 /* If we don't have a default-label, create one here,
4740 after the body of the switch. */
4741 if (thiscase->data.case_stmt.default_label == 0)
4743 thiscase->data.case_stmt.default_label
4744 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4745 expand_label (thiscase->data.case_stmt.default_label);
4747 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4749 before_case = get_last_insn ();
4751 /* Simplify the case-list before we count it. */
4752 group_case_nodes (thiscase->data.case_stmt.case_list);
4754 /* Get upper and lower bounds of case values.
4755 Also convert all the case values to the index expr's data type. */
4758 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4760 /* Check low and high label values are integers. */
4761 if (TREE_CODE (n->low) != INTEGER_CST)
4763 if (TREE_CODE (n->high) != INTEGER_CST)
4766 n->low = convert (index_type, n->low);
4767 n->high = convert (index_type, n->high);
4769 /* Count the elements and track the largest and smallest
4770 of them (treating them as signed even if they are not). */
4778 if (INT_CST_LT (n->low, minval))
4780 if (INT_CST_LT (maxval, n->high))
4783 /* A range counts double, since it requires two compares. */
4784 if (! tree_int_cst_equal (n->low, n->high))
4788 orig_minval = minval;
4790 /* Compute span of values. */
4792 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4796 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4798 emit_jump (default_label);
4801 /* If range of values is much bigger than number of values,
4802 make a sequence of conditional branches instead of a dispatch.
4803 If the switch-index is a constant, do it this way
4804 because we can optimize it. */
4806 #ifndef CASE_VALUES_THRESHOLD
4808 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4810 /* If machine does not have a case insn that compares the
4811 bounds, this means extra overhead for dispatch tables
4812 which raises the threshold for using them. */
4813 #define CASE_VALUES_THRESHOLD 5
4814 #endif /* HAVE_casesi */
4815 #endif /* CASE_VALUES_THRESHOLD */
4817 else if (TREE_INT_CST_HIGH (range) != 0
4818 || count < CASE_VALUES_THRESHOLD
4819 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4821 || TREE_CODE (index_expr) == INTEGER_CST
4822 /* These will reduce to a constant. */
4823 || (TREE_CODE (index_expr) == CALL_EXPR
4824 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4825 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4826 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4827 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4828 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4830 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4832 /* If the index is a short or char that we do not have
4833 an insn to handle comparisons directly, convert it to
4834 a full integer now, rather than letting each comparison
4835 generate the conversion. */
4837 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4838 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4839 == CODE_FOR_nothing))
4841 enum machine_mode wider_mode;
4842 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4843 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4844 if (cmp_optab->handlers[(int) wider_mode].insn_code
4845 != CODE_FOR_nothing)
4847 index = convert_to_mode (wider_mode, index, unsignedp);
4853 do_pending_stack_adjust ();
4855 index = protect_from_queue (index, 0);
4856 if (GET_CODE (index) == MEM)
4857 index = copy_to_reg (index);
4858 if (GET_CODE (index) == CONST_INT
4859 || TREE_CODE (index_expr) == INTEGER_CST)
4861 /* Make a tree node with the proper constant value
4862 if we don't already have one. */
4863 if (TREE_CODE (index_expr) != INTEGER_CST)
4866 = build_int_2 (INTVAL (index),
4867 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4868 index_expr = convert (index_type, index_expr);
4871 /* For constant index expressions we need only
4872 issue a unconditional branch to the appropriate
4873 target code. The job of removing any unreachable
4874 code is left to the optimisation phase if the
4875 "-O" option is specified. */
4876 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4877 if (! tree_int_cst_lt (index_expr, n->low)
4878 && ! tree_int_cst_lt (n->high, index_expr))
4882 emit_jump (label_rtx (n->code_label));
4884 emit_jump (default_label);
4888 /* If the index expression is not constant we generate
4889 a binary decision tree to select the appropriate
4890 target code. This is done as follows:
4892 The list of cases is rearranged into a binary tree,
4893 nearly optimal assuming equal probability for each case.
4895 The tree is transformed into RTL, eliminating
4896 redundant test conditions at the same time.
4898 If program flow could reach the end of the
4899 decision tree an unconditional jump to the
4900 default code is emitted. */
4903 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4904 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4905 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4907 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4908 default_label, index_type);
4909 emit_jump_if_reachable (default_label);
4918 enum machine_mode index_mode = SImode;
4919 int index_bits = GET_MODE_BITSIZE (index_mode);
4921 enum machine_mode op_mode;
4923 /* Convert the index to SImode. */
4924 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4925 > GET_MODE_BITSIZE (index_mode))
4927 enum machine_mode omode = TYPE_MODE (index_type);
4928 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4930 /* We must handle the endpoints in the original mode. */
4931 index_expr = build (MINUS_EXPR, index_type,
4932 index_expr, minval);
4933 minval = integer_zero_node;
4934 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4935 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4936 emit_jump_insn (gen_bltu (default_label));
4937 /* Now we can safely truncate. */
4938 index = convert_to_mode (index_mode, index, 0);
4942 if (TYPE_MODE (index_type) != index_mode)
4944 index_expr = convert (type_for_size (index_bits, 0),
4946 index_type = TREE_TYPE (index_expr);
4949 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4952 index = protect_from_queue (index, 0);
4953 do_pending_stack_adjust ();
4955 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4956 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4958 index = copy_to_mode_reg (op_mode, index);
4960 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4962 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4963 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4965 op1 = copy_to_mode_reg (op_mode, op1);
4967 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4969 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4970 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4972 op2 = copy_to_mode_reg (op_mode, op2);
4974 emit_jump_insn (gen_casesi (index, op1, op2,
4975 table_label, default_label));
4979 #ifdef HAVE_tablejump
4980 if (! win && HAVE_tablejump)
4982 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4983 fold (build (MINUS_EXPR, index_type,
4984 index_expr, minval)));
4985 index_type = TREE_TYPE (index_expr);
4986 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4988 index = protect_from_queue (index, 0);
4989 do_pending_stack_adjust ();
4991 do_tablejump (index, TYPE_MODE (index_type),
4992 expand_expr (range, NULL_RTX, VOIDmode, 0),
4993 table_label, default_label);
5000 /* Get table of labels to jump to, in order of case index. */
5002 ncases = TREE_INT_CST_LOW (range) + 1;
5003 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5004 bzero ((char *) labelvec, ncases * sizeof (rtx));
5006 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5008 register HOST_WIDE_INT i
5009 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5014 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
5015 if (i + TREE_INT_CST_LOW (orig_minval)
5016 == TREE_INT_CST_LOW (n->high))
5022 /* Fill in the gaps with the default. */
5023 for (i = 0; i < ncases; i++)
5024 if (labelvec[i] == 0)
5025 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
5027 /* Output the table */
5028 emit_label (table_label);
5030 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
5031 were an expression, instead of an #ifdef/#ifndef. */
5033 #ifdef CASE_VECTOR_PC_RELATIVE
5037 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
5038 gen_rtx (LABEL_REF, Pmode, table_label),
5039 gen_rtvec_v (ncases, labelvec)));
5041 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
5042 gen_rtvec_v (ncases, labelvec)));
5044 /* If the case insn drops through the table,
5045 after the table we must jump to the default-label.
5046 Otherwise record no drop-through after the table. */
5047 #ifdef CASE_DROPS_THROUGH
5048 emit_jump (default_label);
5054 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5055 reorder_insns (before_case, get_last_insn (),
5056 thiscase->data.case_stmt.start);
5059 if (thiscase->exit_label)
5060 emit_label (thiscase->exit_label);
5062 POPSTACK (case_stack);
5068 /* Terminate a case statement. EXPR is the original index
5072 bc_expand_end_case (expr)
5075 struct nesting *thiscase = case_stack;
5076 enum bytecode_opcode opcode;
5077 struct bc_label *jump_label;
5078 struct case_node *c;
5080 bc_emit_bytecode (jump);
5081 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5083 #ifdef DEBUG_PRINT_CODE
5084 fputc ('\n', stderr);
5087 /* Now that the size of the jump table is known, emit the actual
5088 indexed jump instruction. */
5089 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5091 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5092 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5093 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5095 bc_emit_bytecode (opcode);
5097 /* Now emit the case instructions literal arguments, in order.
5098 In addition to the value on the stack, it uses:
5099 1. The address of the jump table.
5100 2. The size of the jump table.
5101 3. The default label. */
5103 jump_label = bc_get_bytecode_label ();
5104 bc_emit_bytecode_labelref (jump_label);
5105 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5106 sizeof thiscase->data.case_stmt.num_ranges);
5108 if (thiscase->data.case_stmt.default_label)
5109 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5111 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5113 /* Output the jump table. */
5115 bc_align_bytecode (3 /* PTR_ALIGN */);
5116 bc_emit_bytecode_labeldef (jump_label);
5118 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5119 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5121 opcode = TREE_INT_CST_LOW (c->low);
5122 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5124 opcode = TREE_INT_CST_LOW (c->high);
5125 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5127 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5130 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5131 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5133 bc_emit_bytecode_DI_const (c->low);
5134 bc_emit_bytecode_DI_const (c->high);
5136 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5143 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5145 /* Possibly issue enumeration warnings. */
5147 if (!thiscase->data.case_stmt.default_label
5148 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5149 && TREE_CODE (expr) != INTEGER_CST
5151 check_for_full_enumeration_handling (TREE_TYPE (expr));
5154 #ifdef DEBUG_PRINT_CODE
5155 fputc ('\n', stderr);
5158 POPSTACK (case_stack);
5162 /* Return unique bytecode ID. */
5167 static int bc_uid = 0;
5172 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5175 do_jump_if_equal (op1, op2, label, unsignedp)
5176 rtx op1, op2, label;
5179 if (GET_CODE (op1) == CONST_INT
5180 && GET_CODE (op2) == CONST_INT)
5182 if (INTVAL (op1) == INTVAL (op2))
5187 enum machine_mode mode = GET_MODE (op1);
5188 if (mode == VOIDmode)
5189 mode = GET_MODE (op2);
5190 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5191 emit_jump_insn (gen_beq (label));
5195 /* Not all case values are encountered equally. This function
5196 uses a heuristic to weight case labels, in cases where that
5197 looks like a reasonable thing to do.
5199 Right now, all we try to guess is text, and we establish the
5202 chars above space: 16
5211 If we find any cases in the switch that are not either -1 or in the range
5212 of valid ASCII characters, or are control characters other than those
5213 commonly used with "\", don't treat this switch scanning text.
5215 Return 1 if these nodes are suitable for cost estimation, otherwise
5219 estimate_case_costs (node)
5222 tree min_ascii = build_int_2 (-1, -1);
5223 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5227 /* If we haven't already made the cost table, make it now. Note that the
5228 lower bound of the table is -1, not zero. */
5230 if (cost_table == NULL)
5232 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5233 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5235 for (i = 0; i < 128; i++)
5239 else if (ispunct (i))
5241 else if (iscntrl (i))
5245 cost_table[' '] = 8;
5246 cost_table['\t'] = 4;
5247 cost_table['\0'] = 4;
5248 cost_table['\n'] = 2;
5249 cost_table['\f'] = 1;
5250 cost_table['\v'] = 1;
5251 cost_table['\b'] = 1;
5254 /* See if all the case expressions look like text. It is text if the
5255 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5256 as signed arithmetic since we don't want to ever access cost_table with a
5257 value less than -1. Also check that none of the constants in a range
5258 are strange control characters. */
5260 for (n = node; n; n = n->right)
5262 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5265 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5266 if (cost_table[i] < 0)
5270 /* All interesting values are within the range of interesting
5271 ASCII characters. */
5275 /* Scan an ordered list of case nodes
5276 combining those with consecutive values or ranges.
5278 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5281 group_case_nodes (head)
5284 case_node_ptr node = head;
5288 rtx lb = next_real_insn (label_rtx (node->code_label));
5289 case_node_ptr np = node;
5291 /* Try to group the successors of NODE with NODE. */
5292 while (((np = np->right) != 0)
5293 /* Do they jump to the same place? */
5294 && next_real_insn (label_rtx (np->code_label)) == lb
5295 /* Are their ranges consecutive? */
5296 && tree_int_cst_equal (np->low,
5297 fold (build (PLUS_EXPR,
5298 TREE_TYPE (node->high),
5301 /* An overflow is not consecutive. */
5302 && tree_int_cst_lt (node->high,
5303 fold (build (PLUS_EXPR,
5304 TREE_TYPE (node->high),
5306 integer_one_node))))
5308 node->high = np->high;
5310 /* NP is the first node after NODE which can't be grouped with it.
5311 Delete the nodes in between, and move on to that node. */
5317 /* Take an ordered list of case nodes
5318 and transform them into a near optimal binary tree,
5319 on the assumption that any target code selection value is as
5320 likely as any other.
5322 The transformation is performed by splitting the ordered
5323 list into two equal sections plus a pivot. The parts are
5324 then attached to the pivot as left and right branches. Each
5325 branch is is then transformed recursively. */
5328 balance_case_nodes (head, parent)
5329 case_node_ptr *head;
5330 case_node_ptr parent;
5332 register case_node_ptr np;
5340 register case_node_ptr *npp;
5343 /* Count the number of entries on branch. Also count the ranges. */
5347 if (!tree_int_cst_equal (np->low, np->high))
5351 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5355 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5363 /* Split this list if it is long enough for that to help. */
5368 /* Find the place in the list that bisects the list's total cost,
5369 Here I gets half the total cost. */
5374 /* Skip nodes while their cost does not reach that amount. */
5375 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5376 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5377 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5380 npp = &(*npp)->right;
5385 /* Leave this branch lopsided, but optimize left-hand
5386 side and fill in `parent' fields for right-hand side. */
5388 np->parent = parent;
5389 balance_case_nodes (&np->left, np);
5390 for (; np->right; np = np->right)
5391 np->right->parent = np;
5395 /* If there are just three nodes, split at the middle one. */
5397 npp = &(*npp)->right;
5400 /* Find the place in the list that bisects the list's total cost,
5401 where ranges count as 2.
5402 Here I gets half the total cost. */
5403 i = (i + ranges + 1) / 2;
5406 /* Skip nodes while their cost does not reach that amount. */
5407 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5412 npp = &(*npp)->right;
5417 np->parent = parent;
5420 /* Optimize each of the two split parts. */
5421 balance_case_nodes (&np->left, np);
5422 balance_case_nodes (&np->right, np);
5426 /* Else leave this branch as one level,
5427 but fill in `parent' fields. */
5429 np->parent = parent;
5430 for (; np->right; np = np->right)
5431 np->right->parent = np;
5436 /* Search the parent sections of the case node tree
5437 to see if a test for the lower bound of NODE would be redundant.
5438 INDEX_TYPE is the type of the index expression.
5440 The instructions to generate the case decision tree are
5441 output in the same order as nodes are processed so it is
5442 known that if a parent node checks the range of the current
5443 node minus one that the current node is bounded at its lower
5444 span. Thus the test would be redundant. */
5447 node_has_low_bound (node, index_type)
5452 case_node_ptr pnode;
5454 /* If the lower bound of this node is the lowest value in the index type,
5455 we need not test it. */
5457 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5460 /* If this node has a left branch, the value at the left must be less
5461 than that at this node, so it cannot be bounded at the bottom and
5462 we need not bother testing any further. */
5467 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5468 node->low, integer_one_node));
5470 /* If the subtraction above overflowed, we can't verify anything.
5471 Otherwise, look for a parent that tests our value - 1. */
5473 if (! tree_int_cst_lt (low_minus_one, node->low))
5476 for (pnode = node->parent; pnode; pnode = pnode->parent)
5477 if (tree_int_cst_equal (low_minus_one, pnode->high))
5483 /* Search the parent sections of the case node tree
5484 to see if a test for the upper bound of NODE would be redundant.
5485 INDEX_TYPE is the type of the index expression.
5487 The instructions to generate the case decision tree are
5488 output in the same order as nodes are processed so it is
5489 known that if a parent node checks the range of the current
5490 node plus one that the current node is bounded at its upper
5491 span. Thus the test would be redundant. */
5494 node_has_high_bound (node, index_type)
5499 case_node_ptr pnode;
5501 /* If the upper bound of this node is the highest value in the type
5502 of the index expression, we need not test against it. */
5504 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5507 /* If this node has a right branch, the value at the right must be greater
5508 than that at this node, so it cannot be bounded at the top and
5509 we need not bother testing any further. */
5514 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5515 node->high, integer_one_node));
5517 /* If the addition above overflowed, we can't verify anything.
5518 Otherwise, look for a parent that tests our value + 1. */
5520 if (! tree_int_cst_lt (node->high, high_plus_one))
5523 for (pnode = node->parent; pnode; pnode = pnode->parent)
5524 if (tree_int_cst_equal (high_plus_one, pnode->low))
5530 /* Search the parent sections of the
5531 case node tree to see if both tests for the upper and lower
5532 bounds of NODE would be redundant. */
5535 node_is_bounded (node, index_type)
5539 return (node_has_low_bound (node, index_type)
5540 && node_has_high_bound (node, index_type));
5543 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5546 emit_jump_if_reachable (label)
5549 if (GET_CODE (get_last_insn ()) != BARRIER)
5553 /* Emit step-by-step code to select a case for the value of INDEX.
5554 The thus generated decision tree follows the form of the
5555 case-node binary tree NODE, whose nodes represent test conditions.
5556 INDEX_TYPE is the type of the index of the switch.
5558 Care is taken to prune redundant tests from the decision tree
5559 by detecting any boundary conditions already checked by
5560 emitted rtx. (See node_has_high_bound, node_has_low_bound
5561 and node_is_bounded, above.)
5563 Where the test conditions can be shown to be redundant we emit
5564 an unconditional jump to the target code. As a further
5565 optimization, the subordinates of a tree node are examined to
5566 check for bounded nodes. In this case conditional and/or
5567 unconditional jumps as a result of the boundary check for the
5568 current node are arranged to target the subordinates associated
5569 code for out of bound conditions on the current node node.
5571 We can assume that when control reaches the code generated here,
5572 the index value has already been compared with the parents
5573 of this node, and determined to be on the same side of each parent
5574 as this node is. Thus, if this node tests for the value 51,
5575 and a parent tested for 52, we don't need to consider
5576 the possibility of a value greater than 51. If another parent
5577 tests for the value 50, then this node need not test anything. */
5580 emit_case_nodes (index, node, default_label, index_type)
5586 /* If INDEX has an unsigned type, we must make unsigned branches. */
5587 int unsignedp = TREE_UNSIGNED (index_type);
5588 typedef rtx rtx_function ();
5589 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5590 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5591 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5592 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5593 enum machine_mode mode = GET_MODE (index);
5595 /* See if our parents have already tested everything for us.
5596 If they have, emit an unconditional jump for this node. */
5597 if (node_is_bounded (node, index_type))
5598 emit_jump (label_rtx (node->code_label));
5600 else if (tree_int_cst_equal (node->low, node->high))
5602 /* Node is single valued. First see if the index expression matches
5603 this node and then check our children, if any. */
5605 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5606 label_rtx (node->code_label), unsignedp);
5608 if (node->right != 0 && node->left != 0)
5610 /* This node has children on both sides.
5611 Dispatch to one side or the other
5612 by comparing the index value with this node's value.
5613 If one subtree is bounded, check that one first,
5614 so we can avoid real branches in the tree. */
5616 if (node_is_bounded (node->right, index_type))
5618 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5620 GT, NULL_RTX, mode, unsignedp, 0);
5622 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5623 emit_case_nodes (index, node->left, default_label, index_type);
5626 else if (node_is_bounded (node->left, index_type))
5628 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5630 LT, NULL_RTX, mode, unsignedp, 0);
5631 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5632 emit_case_nodes (index, node->right, default_label, index_type);
5637 /* Neither node is bounded. First distinguish the two sides;
5638 then emit the code for one side at a time. */
5641 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5643 /* See if the value is on the right. */
5644 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5646 GT, NULL_RTX, mode, unsignedp, 0);
5647 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5649 /* Value must be on the left.
5650 Handle the left-hand subtree. */
5651 emit_case_nodes (index, node->left, default_label, index_type);
5652 /* If left-hand subtree does nothing,
5654 emit_jump_if_reachable (default_label);
5656 /* Code branches here for the right-hand subtree. */
5657 expand_label (test_label);
5658 emit_case_nodes (index, node->right, default_label, index_type);
5662 else if (node->right != 0 && node->left == 0)
5664 /* Here we have a right child but no left so we issue conditional
5665 branch to default and process the right child.
5667 Omit the conditional branch to default if we it avoid only one
5668 right child; it costs too much space to save so little time. */
5670 if (node->right->right || node->right->left
5671 || !tree_int_cst_equal (node->right->low, node->right->high))
5673 if (!node_has_low_bound (node, index_type))
5675 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5677 LT, NULL_RTX, mode, unsignedp, 0);
5678 emit_jump_insn ((*gen_blt_pat) (default_label));
5681 emit_case_nodes (index, node->right, default_label, index_type);
5684 /* We cannot process node->right normally
5685 since we haven't ruled out the numbers less than
5686 this node's value. So handle node->right explicitly. */
5687 do_jump_if_equal (index,
5688 expand_expr (node->right->low, NULL_RTX,
5690 label_rtx (node->right->code_label), unsignedp);
5693 else if (node->right == 0 && node->left != 0)
5695 /* Just one subtree, on the left. */
5697 #if 0 /* The following code and comment were formerly part
5698 of the condition here, but they didn't work
5699 and I don't understand what the idea was. -- rms. */
5700 /* If our "most probable entry" is less probable
5701 than the default label, emit a jump to
5702 the default label using condition codes
5703 already lying around. With no right branch,
5704 a branch-greater-than will get us to the default
5707 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5710 if (node->left->left || node->left->right
5711 || !tree_int_cst_equal (node->left->low, node->left->high))
5713 if (!node_has_high_bound (node, index_type))
5715 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5717 GT, NULL_RTX, mode, unsignedp, 0);
5718 emit_jump_insn ((*gen_bgt_pat) (default_label));
5721 emit_case_nodes (index, node->left, default_label, index_type);
5724 /* We cannot process node->left normally
5725 since we haven't ruled out the numbers less than
5726 this node's value. So handle node->left explicitly. */
5727 do_jump_if_equal (index,
5728 expand_expr (node->left->low, NULL_RTX,
5730 label_rtx (node->left->code_label), unsignedp);
5735 /* Node is a range. These cases are very similar to those for a single
5736 value, except that we do not start by testing whether this node
5737 is the one to branch to. */
5739 if (node->right != 0 && node->left != 0)
5741 /* Node has subtrees on both sides.
5742 If the right-hand subtree is bounded,
5743 test for it first, since we can go straight there.
5744 Otherwise, we need to make a branch in the control structure,
5745 then handle the two subtrees. */
5746 tree test_label = 0;
5748 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5750 GT, NULL_RTX, mode, unsignedp, 0);
5752 if (node_is_bounded (node->right, index_type))
5753 /* Right hand node is fully bounded so we can eliminate any
5754 testing and branch directly to the target code. */
5755 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5758 /* Right hand node requires testing.
5759 Branch to a label where we will handle it later. */
5761 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5762 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5765 /* Value belongs to this node or to the left-hand subtree. */
5767 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5768 GE, NULL_RTX, mode, unsignedp, 0);
5769 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5771 /* Handle the left-hand subtree. */
5772 emit_case_nodes (index, node->left, default_label, index_type);
5774 /* If right node had to be handled later, do that now. */
5778 /* If the left-hand subtree fell through,
5779 don't let it fall into the right-hand subtree. */
5780 emit_jump_if_reachable (default_label);
5782 expand_label (test_label);
5783 emit_case_nodes (index, node->right, default_label, index_type);
5787 else if (node->right != 0 && node->left == 0)
5789 /* Deal with values to the left of this node,
5790 if they are possible. */
5791 if (!node_has_low_bound (node, index_type))
5793 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5795 LT, NULL_RTX, mode, unsignedp, 0);
5796 emit_jump_insn ((*gen_blt_pat) (default_label));
5799 /* Value belongs to this node or to the right-hand subtree. */
5801 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5803 LE, NULL_RTX, mode, unsignedp, 0);
5804 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5806 emit_case_nodes (index, node->right, default_label, index_type);
5809 else if (node->right == 0 && node->left != 0)
5811 /* Deal with values to the right of this node,
5812 if they are possible. */
5813 if (!node_has_high_bound (node, index_type))
5815 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5817 GT, NULL_RTX, mode, unsignedp, 0);
5818 emit_jump_insn ((*gen_bgt_pat) (default_label));
5821 /* Value belongs to this node or to the left-hand subtree. */
5823 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5824 GE, NULL_RTX, mode, unsignedp, 0);
5825 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5827 emit_case_nodes (index, node->left, default_label, index_type);
5832 /* Node has no children so we check low and high bounds to remove
5833 redundant tests. Only one of the bounds can exist,
5834 since otherwise this node is bounded--a case tested already. */
5836 if (!node_has_high_bound (node, index_type))
5838 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5840 GT, NULL_RTX, mode, unsignedp, 0);
5841 emit_jump_insn ((*gen_bgt_pat) (default_label));
5844 if (!node_has_low_bound (node, index_type))
5846 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5848 LT, NULL_RTX, mode, unsignedp, 0);
5849 emit_jump_insn ((*gen_blt_pat) (default_label));
5852 emit_jump (label_rtx (node->code_label));
5857 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5858 so that the debugging info will be correct for the unrolled loop. */
5860 /* Indexed by block number, contains a pointer to the N'th block node. */
5862 static tree *block_vector;
5865 find_loop_tree_blocks ()
5867 tree block = DECL_INITIAL (current_function_decl);
5869 block_vector = identify_blocks (block, get_insns ());
5873 unroll_block_trees ()
5875 tree block = DECL_INITIAL (current_function_decl);
5877 reorder_blocks (block_vector, block, get_insns ());