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 'V': case 'm': case 'o': case '<': case '>':
1431 case 'E': case 'F': case 'G': case 'H': case 'X':
1432 case 's': case 'i': case 'n':
1433 case 'I': case 'J': case 'K': case 'L': case 'M':
1434 case 'N': case 'O': case 'P': case ',':
1435 #ifdef EXTRA_CONSTRAINT
1436 case 'Q': case 'R': case 'S': case 'T': case 'U':
1440 case 'p': case 'g': case 'r':
1441 /* Whether or not a numeric constraint allows a register is
1442 decided by the matching constraint, and so there is no need
1443 to do anything special with them. We must handle them in
1444 the default case, so that we don't unnecessarily force
1445 operands to memory. */
1446 case '0': case '1': case '2': case '3': case '4':
1454 error ("output operand constraint lacks `='");
1458 /* If an output operand is not a decl or indirect ref and our constraint
1459 allows a register, make a temporary to act as an intermediate.
1460 Make the asm insn write into that, then our caller will copy it to
1461 the real output operand. Likewise for promoted variables. */
1463 if (TREE_CODE (val) == INDIRECT_REF
1464 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1465 && ! (GET_CODE (DECL_RTL (val)) == REG
1466 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1470 mark_addressable (TREE_VALUE (tail));
1473 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1475 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1476 error ("output number %d not directly addressable", i);
1480 if (TYPE_MODE (type) == BLKmode)
1482 output_rtx[i] = assign_stack_temp (BLKmode,
1483 int_size_in_bytes (type), 0);
1484 MEM_IN_STRUCT_P (output_rtx[i]) = AGGREGATE_TYPE_P (type);
1487 output_rtx[i] = gen_reg_rtx (TYPE_MODE (type));
1489 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1493 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1495 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1499 /* Make vectors for the expression-rtx and constraint strings. */
1501 argvec = rtvec_alloc (ninputs);
1502 constraints = rtvec_alloc (ninputs);
1504 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1505 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1507 MEM_VOLATILE_P (body) = vol;
1509 /* Eval the inputs and put them into ARGVEC.
1510 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1513 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1518 /* If there's an erroneous arg, emit no insn,
1519 because the ASM_INPUT would get VOIDmode
1520 and that could cause a crash in reload. */
1521 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1523 if (TREE_PURPOSE (tail) == NULL_TREE)
1525 error ("hard register `%s' listed as input operand to `asm'",
1526 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1530 /* Make sure constraint has neither `=' nor `+'. */
1532 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1533 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1536 error ("input operand constraint contains `%c'",
1537 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1540 case '?': case '!': case '*': case '%': case '&':
1541 case 'V': case 'm': case 'o': case '<': case '>':
1542 case 'E': case 'F': case 'G': case 'H': case 'X':
1543 case 's': case 'i': case 'n':
1544 case 'I': case 'J': case 'K': case 'L': case 'M':
1545 case 'N': case 'O': case 'P': case ',':
1546 #ifdef EXTRA_CONSTRAINT
1547 case 'Q': case 'R': case 'S': case 'T': case 'U':
1551 case 'p': case 'g': case 'r':
1552 /* Whether or not a numeric constraint allows a register is
1553 decided by the matching constraint, and so there is no need
1554 to do anything special with them. We must handle them in
1555 the default case, so that we don't unnecessarily force
1556 operands to memory. */
1557 case '0': case '1': case '2': case '3': case '4':
1564 mark_addressable (TREE_VALUE (tail));
1566 XVECEXP (body, 3, i) /* argvec */
1567 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1568 if (CONSTANT_P (XVECEXP (body, 3, i))
1569 && ! general_operand (XVECEXP (body, 3, i),
1570 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1573 XVECEXP (body, 3, i)
1574 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1575 XVECEXP (body, 3, i));
1577 XVECEXP (body, 3, i)
1578 = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1579 XVECEXP (body, 3, i));
1583 && (GET_CODE (XVECEXP (body, 3, i)) == REG
1584 || GET_CODE (XVECEXP (body, 3, i)) == SUBREG
1585 || GET_CODE (XVECEXP (body, 3, i)) == CONCAT))
1587 tree type = TREE_TYPE (TREE_VALUE (tail));
1588 rtx memloc = assign_stack_temp (TYPE_MODE (type),
1589 int_size_in_bytes (type), 1);
1591 MEM_IN_STRUCT_P (memloc) = AGGREGATE_TYPE_P (type);
1592 emit_move_insn (memloc, XVECEXP (body, 3, i));
1593 XVECEXP (body, 3, i) = memloc;
1596 XVECEXP (body, 4, i) /* constraints */
1597 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1598 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1602 /* Protect all the operands from the queue,
1603 now that they have all been evaluated. */
1605 for (i = 0; i < ninputs; i++)
1606 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1608 for (i = 0; i < noutputs; i++)
1609 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1611 /* Now, for each output, construct an rtx
1612 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1613 ARGVEC CONSTRAINTS))
1614 If there is more than one, put them inside a PARALLEL. */
1616 if (noutputs == 1 && nclobbers == 0)
1618 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1619 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1621 else if (noutputs == 0 && nclobbers == 0)
1623 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1624 insn = emit_insn (body);
1630 if (num == 0) num = 1;
1631 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1633 /* For each output operand, store a SET. */
1635 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1637 XVECEXP (body, 0, i)
1638 = gen_rtx (SET, VOIDmode,
1640 gen_rtx (ASM_OPERANDS, VOIDmode,
1641 TREE_STRING_POINTER (string),
1642 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1643 i, argvec, constraints,
1645 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1648 /* If there are no outputs (but there are some clobbers)
1649 store the bare ASM_OPERANDS into the PARALLEL. */
1652 XVECEXP (body, 0, i++) = obody;
1654 /* Store (clobber REG) for each clobbered register specified. */
1656 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1658 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1659 int j = decode_reg_name (regname);
1663 if (j == -3) /* `cc', which is not a register */
1666 if (j == -4) /* `memory', don't cache memory across asm */
1668 XVECEXP (body, 0, i++)
1669 = gen_rtx (CLOBBER, VOIDmode,
1670 gen_rtx (MEM, BLKmode,
1671 gen_rtx (SCRATCH, VOIDmode, 0)));
1675 /* Ignore unknown register, error already signalled. */
1679 /* Use QImode since that's guaranteed to clobber just one reg. */
1680 XVECEXP (body, 0, i++)
1681 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1684 insn = emit_insn (body);
1690 /* Generate RTL to evaluate the expression EXP
1691 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1694 expand_expr_stmt (exp)
1697 if (output_bytecode)
1699 int org_stack_depth = stack_depth;
1701 bc_expand_expr (exp);
1703 /* Restore stack depth */
1704 if (stack_depth < org_stack_depth)
1707 bc_emit_instruction (drop);
1709 last_expr_type = TREE_TYPE (exp);
1713 /* If -W, warn about statements with no side effects,
1714 except for an explicit cast to void (e.g. for assert()), and
1715 except inside a ({...}) where they may be useful. */
1716 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1718 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1719 && !(TREE_CODE (exp) == CONVERT_EXPR
1720 && TREE_TYPE (exp) == void_type_node))
1721 warning_with_file_and_line (emit_filename, emit_lineno,
1722 "statement with no effect");
1723 else if (warn_unused)
1724 warn_if_unused_value (exp);
1727 /* If EXP is of function type and we are expanding statements for
1728 value, convert it to pointer-to-function. */
1729 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1730 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1732 last_expr_type = TREE_TYPE (exp);
1733 if (! flag_syntax_only)
1734 last_expr_value = expand_expr (exp,
1735 (expr_stmts_for_value
1736 ? NULL_RTX : const0_rtx),
1739 /* If all we do is reference a volatile value in memory,
1740 copy it to a register to be sure it is actually touched. */
1741 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1742 && TREE_THIS_VOLATILE (exp))
1744 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1746 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1747 copy_to_reg (last_expr_value);
1750 rtx lab = gen_label_rtx ();
1752 /* Compare the value with itself to reference it. */
1753 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1754 expand_expr (TYPE_SIZE (last_expr_type),
1755 NULL_RTX, VOIDmode, 0),
1757 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1758 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1763 /* If this expression is part of a ({...}) and is in memory, we may have
1764 to preserve temporaries. */
1765 preserve_temp_slots (last_expr_value);
1767 /* Free any temporaries used to evaluate this expression. Any temporary
1768 used as a result of this expression will already have been preserved
1775 /* Warn if EXP contains any computations whose results are not used.
1776 Return 1 if a warning is printed; 0 otherwise. */
1779 warn_if_unused_value (exp)
1782 if (TREE_USED (exp))
1785 switch (TREE_CODE (exp))
1787 case PREINCREMENT_EXPR:
1788 case POSTINCREMENT_EXPR:
1789 case PREDECREMENT_EXPR:
1790 case POSTDECREMENT_EXPR:
1795 case METHOD_CALL_EXPR:
1797 case WITH_CLEANUP_EXPR:
1799 /* We don't warn about COND_EXPR because it may be a useful
1800 construct if either arm contains a side effect. */
1805 /* For a binding, warn if no side effect within it. */
1806 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1809 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1811 case TRUTH_ORIF_EXPR:
1812 case TRUTH_ANDIF_EXPR:
1813 /* In && or ||, warn if 2nd operand has no side effect. */
1814 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1817 if (TREE_NO_UNUSED_WARNING (exp))
1819 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1821 /* Let people do `(foo (), 0)' without a warning. */
1822 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1824 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1828 case NON_LVALUE_EXPR:
1829 /* Don't warn about values cast to void. */
1830 if (TREE_TYPE (exp) == void_type_node)
1832 /* Don't warn about conversions not explicit in the user's program. */
1833 if (TREE_NO_UNUSED_WARNING (exp))
1835 /* Assignment to a cast usually results in a cast of a modify.
1836 Don't complain about that. There can be an arbitrary number of
1837 casts before the modify, so we must loop until we find the first
1838 non-cast expression and then test to see if that is a modify. */
1840 tree tem = TREE_OPERAND (exp, 0);
1842 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1843 tem = TREE_OPERAND (tem, 0);
1845 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1846 || TREE_CODE (tem) == CALL_EXPR)
1852 /* Don't warn about automatic dereferencing of references, since
1853 the user cannot control it. */
1854 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1855 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1856 /* ... fall through ... */
1859 /* Referencing a volatile value is a side effect, so don't warn. */
1860 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1861 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1862 && TREE_THIS_VOLATILE (exp))
1865 warning_with_file_and_line (emit_filename, emit_lineno,
1866 "value computed is not used");
1871 /* Clear out the memory of the last expression evaluated. */
1879 /* Begin a statement which will return a value.
1880 Return the RTL_EXPR for this statement expr.
1881 The caller must save that value and pass it to expand_end_stmt_expr. */
1884 expand_start_stmt_expr ()
1889 /* When generating bytecode just note down the stack depth */
1890 if (output_bytecode)
1891 return (build_int_2 (stack_depth, 0));
1893 /* Make the RTL_EXPR node temporary, not momentary,
1894 so that rtl_expr_chain doesn't become garbage. */
1895 momentary = suspend_momentary ();
1896 t = make_node (RTL_EXPR);
1897 resume_momentary (momentary);
1898 do_pending_stack_adjust ();
1899 start_sequence_for_rtl_expr (t);
1901 expr_stmts_for_value++;
1905 /* Restore the previous state at the end of a statement that returns a value.
1906 Returns a tree node representing the statement's value and the
1907 insns to compute the value.
1909 The nodes of that expression have been freed by now, so we cannot use them.
1910 But we don't want to do that anyway; the expression has already been
1911 evaluated and now we just want to use the value. So generate a RTL_EXPR
1912 with the proper type and RTL value.
1914 If the last substatement was not an expression,
1915 return something with type `void'. */
1918 expand_end_stmt_expr (t)
1921 if (output_bytecode)
1927 /* At this point, all expressions have been evaluated in order.
1928 However, all expression values have been popped when evaluated,
1929 which means we have to recover the last expression value. This is
1930 the last value removed by means of a `drop' instruction. Instead
1931 of adding code to inhibit dropping the last expression value, it
1932 is here recovered by undoing the `drop'. Since `drop' is
1933 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1936 bc_adjust_stack (-1);
1938 if (!last_expr_type)
1939 last_expr_type = void_type_node;
1941 t = make_node (RTL_EXPR);
1942 TREE_TYPE (t) = last_expr_type;
1943 RTL_EXPR_RTL (t) = NULL;
1944 RTL_EXPR_SEQUENCE (t) = NULL;
1946 /* Don't consider deleting this expr or containing exprs at tree level. */
1947 TREE_THIS_VOLATILE (t) = 1;
1955 if (last_expr_type == 0)
1957 last_expr_type = void_type_node;
1958 last_expr_value = const0_rtx;
1960 else if (last_expr_value == 0)
1961 /* There are some cases where this can happen, such as when the
1962 statement is void type. */
1963 last_expr_value = const0_rtx;
1964 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1965 /* Remove any possible QUEUED. */
1966 last_expr_value = protect_from_queue (last_expr_value, 0);
1970 TREE_TYPE (t) = last_expr_type;
1971 RTL_EXPR_RTL (t) = last_expr_value;
1972 RTL_EXPR_SEQUENCE (t) = get_insns ();
1974 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1978 /* Don't consider deleting this expr or containing exprs at tree level. */
1979 TREE_SIDE_EFFECTS (t) = 1;
1980 /* Propagate volatility of the actual RTL expr. */
1981 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1984 expr_stmts_for_value--;
1989 /* Generate RTL for the start of an if-then. COND is the expression
1990 whose truth should be tested.
1992 If EXITFLAG is nonzero, this conditional is visible to
1993 `exit_something'. */
1996 expand_start_cond (cond, exitflag)
2000 struct nesting *thiscond = ALLOC_NESTING ();
2002 /* Make an entry on cond_stack for the cond we are entering. */
2004 thiscond->next = cond_stack;
2005 thiscond->all = nesting_stack;
2006 thiscond->depth = ++nesting_depth;
2007 thiscond->data.cond.next_label = gen_label_rtx ();
2008 /* Before we encounter an `else', we don't need a separate exit label
2009 unless there are supposed to be exit statements
2010 to exit this conditional. */
2011 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2012 thiscond->data.cond.endif_label = thiscond->exit_label;
2013 cond_stack = thiscond;
2014 nesting_stack = thiscond;
2016 if (output_bytecode)
2017 bc_expand_start_cond (cond, exitflag);
2019 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2022 /* Generate RTL between then-clause and the elseif-clause
2023 of an if-then-elseif-.... */
2026 expand_start_elseif (cond)
2029 if (cond_stack->data.cond.endif_label == 0)
2030 cond_stack->data.cond.endif_label = gen_label_rtx ();
2031 emit_jump (cond_stack->data.cond.endif_label);
2032 emit_label (cond_stack->data.cond.next_label);
2033 cond_stack->data.cond.next_label = gen_label_rtx ();
2034 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2037 /* Generate RTL between the then-clause and the else-clause
2038 of an if-then-else. */
2041 expand_start_else ()
2043 if (cond_stack->data.cond.endif_label == 0)
2044 cond_stack->data.cond.endif_label = gen_label_rtx ();
2046 if (output_bytecode)
2048 bc_expand_start_else ();
2052 emit_jump (cond_stack->data.cond.endif_label);
2053 emit_label (cond_stack->data.cond.next_label);
2054 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2057 /* After calling expand_start_else, turn this "else" into an "else if"
2058 by providing another condition. */
2061 expand_elseif (cond)
2064 cond_stack->data.cond.next_label = gen_label_rtx ();
2065 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2068 /* Generate RTL for the end of an if-then.
2069 Pop the record for it off of cond_stack. */
2074 struct nesting *thiscond = cond_stack;
2076 if (output_bytecode)
2077 bc_expand_end_cond ();
2080 do_pending_stack_adjust ();
2081 if (thiscond->data.cond.next_label)
2082 emit_label (thiscond->data.cond.next_label);
2083 if (thiscond->data.cond.endif_label)
2084 emit_label (thiscond->data.cond.endif_label);
2087 POPSTACK (cond_stack);
2092 /* Generate code for the start of an if-then. COND is the expression
2093 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2094 is to be visible to exit_something. It is assumed that the caller
2095 has pushed the previous context on the cond stack. */
2098 bc_expand_start_cond (cond, exitflag)
2102 struct nesting *thiscond = cond_stack;
2104 thiscond->data.case_stmt.nominal_type = cond;
2106 thiscond->exit_label = gen_label_rtx ();
2107 bc_expand_expr (cond);
2108 bc_emit_bytecode (xjumpifnot);
2109 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2111 #ifdef DEBUG_PRINT_CODE
2112 fputc ('\n', stderr);
2116 /* Generate the label for the end of an if with
2120 bc_expand_end_cond ()
2122 struct nesting *thiscond = cond_stack;
2124 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2127 /* Generate code for the start of the else- clause of
2131 bc_expand_start_else ()
2133 struct nesting *thiscond = cond_stack;
2135 thiscond->data.cond.endif_label = thiscond->exit_label;
2136 thiscond->exit_label = gen_label_rtx ();
2137 bc_emit_bytecode (jump);
2138 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2140 #ifdef DEBUG_PRINT_CODE
2141 fputc ('\n', stderr);
2144 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2147 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2148 loop should be exited by `exit_something'. This is a loop for which
2149 `expand_continue' will jump to the top of the loop.
2151 Make an entry on loop_stack to record the labels associated with
2155 expand_start_loop (exit_flag)
2158 register struct nesting *thisloop = ALLOC_NESTING ();
2160 /* Make an entry on loop_stack for the loop we are entering. */
2162 thisloop->next = loop_stack;
2163 thisloop->all = nesting_stack;
2164 thisloop->depth = ++nesting_depth;
2165 thisloop->data.loop.start_label = gen_label_rtx ();
2166 thisloop->data.loop.end_label = gen_label_rtx ();
2167 thisloop->data.loop.alt_end_label = 0;
2168 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2169 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2170 loop_stack = thisloop;
2171 nesting_stack = thisloop;
2173 if (output_bytecode)
2175 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2179 do_pending_stack_adjust ();
2181 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2182 emit_label (thisloop->data.loop.start_label);
2187 /* Like expand_start_loop but for a loop where the continuation point
2188 (for expand_continue_loop) will be specified explicitly. */
2191 expand_start_loop_continue_elsewhere (exit_flag)
2194 struct nesting *thisloop = expand_start_loop (exit_flag);
2195 loop_stack->data.loop.continue_label = gen_label_rtx ();
2199 /* Specify the continuation point for a loop started with
2200 expand_start_loop_continue_elsewhere.
2201 Use this at the point in the code to which a continue statement
2205 expand_loop_continue_here ()
2207 if (output_bytecode)
2209 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2212 do_pending_stack_adjust ();
2213 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2214 emit_label (loop_stack->data.loop.continue_label);
2220 bc_expand_end_loop ()
2222 struct nesting *thisloop = loop_stack;
2224 bc_emit_bytecode (jump);
2225 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2227 #ifdef DEBUG_PRINT_CODE
2228 fputc ('\n', stderr);
2231 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2232 POPSTACK (loop_stack);
2237 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2238 Pop the block off of loop_stack. */
2244 register rtx start_label;
2245 rtx last_test_insn = 0;
2248 if (output_bytecode)
2250 bc_expand_end_loop ();
2254 insn = get_last_insn ();
2255 start_label = loop_stack->data.loop.start_label;
2257 /* Mark the continue-point at the top of the loop if none elsewhere. */
2258 if (start_label == loop_stack->data.loop.continue_label)
2259 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2261 do_pending_stack_adjust ();
2263 /* If optimizing, perhaps reorder the loop. If the loop
2264 starts with a conditional exit, roll that to the end
2265 where it will optimize together with the jump back.
2267 We look for the last conditional branch to the exit that we encounter
2268 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2269 branch to the exit first, use it.
2271 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2272 because moving them is not valid. */
2276 ! (GET_CODE (insn) == JUMP_INSN
2277 && GET_CODE (PATTERN (insn)) == SET
2278 && SET_DEST (PATTERN (insn)) == pc_rtx
2279 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2281 /* Scan insns from the top of the loop looking for a qualified
2282 conditional exit. */
2283 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2284 insn = NEXT_INSN (insn))
2286 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2289 if (GET_CODE (insn) == NOTE
2290 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2291 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2294 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2297 if (last_test_insn && num_insns > 30)
2300 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2301 && SET_DEST (PATTERN (insn)) == pc_rtx
2302 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2303 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2304 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2305 == loop_stack->data.loop.end_label)
2306 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2307 == loop_stack->data.loop.alt_end_label)))
2308 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2309 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2310 == loop_stack->data.loop.end_label)
2311 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2312 == loop_stack->data.loop.alt_end_label)))))
2313 last_test_insn = insn;
2315 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2316 && GET_CODE (PATTERN (insn)) == SET
2317 && SET_DEST (PATTERN (insn)) == pc_rtx
2318 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2319 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2320 == loop_stack->data.loop.end_label)
2321 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2322 == loop_stack->data.loop.alt_end_label)))
2323 /* Include BARRIER. */
2324 last_test_insn = NEXT_INSN (insn);
2327 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2329 /* We found one. Move everything from there up
2330 to the end of the loop, and add a jump into the loop
2331 to jump to there. */
2332 register rtx newstart_label = gen_label_rtx ();
2333 register rtx start_move = start_label;
2335 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2336 then we want to move this note also. */
2337 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2338 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2339 == NOTE_INSN_LOOP_CONT))
2340 start_move = PREV_INSN (start_move);
2342 emit_label_after (newstart_label, PREV_INSN (start_move));
2343 reorder_insns (start_move, last_test_insn, get_last_insn ());
2344 emit_jump_insn_after (gen_jump (start_label),
2345 PREV_INSN (newstart_label));
2346 emit_barrier_after (PREV_INSN (newstart_label));
2347 start_label = newstart_label;
2351 emit_jump (start_label);
2352 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2353 emit_label (loop_stack->data.loop.end_label);
2355 POPSTACK (loop_stack);
2360 /* Generate a jump to the current loop's continue-point.
2361 This is usually the top of the loop, but may be specified
2362 explicitly elsewhere. If not currently inside a loop,
2363 return 0 and do nothing; caller will print an error message. */
2366 expand_continue_loop (whichloop)
2367 struct nesting *whichloop;
2371 whichloop = loop_stack;
2374 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2379 /* Generate a jump to exit the current loop. If not currently inside a loop,
2380 return 0 and do nothing; caller will print an error message. */
2383 expand_exit_loop (whichloop)
2384 struct nesting *whichloop;
2388 whichloop = loop_stack;
2391 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2395 /* Generate a conditional jump to exit the current loop if COND
2396 evaluates to zero. If not currently inside a loop,
2397 return 0 and do nothing; caller will print an error message. */
2400 expand_exit_loop_if_false (whichloop, cond)
2401 struct nesting *whichloop;
2406 whichloop = loop_stack;
2409 if (output_bytecode)
2411 bc_expand_expr (cond);
2412 bc_expand_goto_internal (xjumpifnot,
2413 BYTECODE_BC_LABEL (whichloop->exit_label),
2418 /* In order to handle fixups, we actually create a conditional jump
2419 around a unconditional branch to exit the loop. If fixups are
2420 necessary, they go before the unconditional branch. */
2422 rtx label = gen_label_rtx ();
2425 do_jump (cond, NULL_RTX, label);
2426 last_insn = get_last_insn ();
2427 if (GET_CODE (last_insn) == CODE_LABEL)
2428 whichloop->data.loop.alt_end_label = last_insn;
2429 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2437 /* Return non-zero if we should preserve sub-expressions as separate
2438 pseudos. We never do so if we aren't optimizing. We always do so
2439 if -fexpensive-optimizations.
2441 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2442 the loop may still be a small one. */
2445 preserve_subexpressions_p ()
2449 if (flag_expensive_optimizations)
2452 if (optimize == 0 || loop_stack == 0)
2455 insn = get_last_insn_anywhere ();
2458 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2459 < n_non_fixed_regs * 3));
2463 /* Generate a jump to exit the current loop, conditional, binding contour
2464 or case statement. Not all such constructs are visible to this function,
2465 only those started with EXIT_FLAG nonzero. Individual languages use
2466 the EXIT_FLAG parameter to control which kinds of constructs you can
2469 If not currently inside anything that can be exited,
2470 return 0 and do nothing; caller will print an error message. */
2473 expand_exit_something ()
2477 for (n = nesting_stack; n; n = n->all)
2478 if (n->exit_label != 0)
2480 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2487 /* Generate RTL to return from the current function, with no value.
2488 (That is, we do not do anything about returning any value.) */
2491 expand_null_return ()
2493 struct nesting *block = block_stack;
2496 if (output_bytecode)
2498 bc_emit_instruction (ret);
2502 /* Does any pending block have cleanups? */
2504 while (block && block->data.block.cleanups == 0)
2505 block = block->next;
2507 /* If yes, use a goto to return, since that runs cleanups. */
2509 expand_null_return_1 (last_insn, block != 0);
2512 /* Generate RTL to return from the current function, with value VAL. */
2515 expand_value_return (val)
2518 struct nesting *block = block_stack;
2519 rtx last_insn = get_last_insn ();
2520 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2522 /* Copy the value to the return location
2523 unless it's already there. */
2525 if (return_reg != val)
2527 #ifdef PROMOTE_FUNCTION_RETURN
2528 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2529 int unsignedp = TREE_UNSIGNED (type);
2530 enum machine_mode mode
2531 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2534 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2535 convert_move (return_reg, val, unsignedp);
2538 emit_move_insn (return_reg, val);
2540 if (GET_CODE (return_reg) == REG
2541 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2542 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2544 /* Does any pending block have cleanups? */
2546 while (block && block->data.block.cleanups == 0)
2547 block = block->next;
2549 /* If yes, use a goto to return, since that runs cleanups.
2550 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2552 expand_null_return_1 (last_insn, block != 0);
2555 /* Output a return with no value. If LAST_INSN is nonzero,
2556 pretend that the return takes place after LAST_INSN.
2557 If USE_GOTO is nonzero then don't use a return instruction;
2558 go to the return label instead. This causes any cleanups
2559 of pending blocks to be executed normally. */
2562 expand_null_return_1 (last_insn, use_goto)
2566 rtx end_label = cleanup_label ? cleanup_label : return_label;
2568 clear_pending_stack_adjust ();
2569 do_pending_stack_adjust ();
2572 /* PCC-struct return always uses an epilogue. */
2573 if (current_function_returns_pcc_struct || use_goto)
2576 end_label = return_label = gen_label_rtx ();
2577 expand_goto_internal (NULL_TREE, end_label, last_insn);
2581 /* Otherwise output a simple return-insn if one is available,
2582 unless it won't do the job. */
2584 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2586 emit_jump_insn (gen_return ());
2592 /* Otherwise jump to the epilogue. */
2593 expand_goto_internal (NULL_TREE, end_label, last_insn);
2596 /* Generate RTL to evaluate the expression RETVAL and return it
2597 from the current function. */
2600 expand_return (retval)
2603 /* If there are any cleanups to be performed, then they will
2604 be inserted following LAST_INSN. It is desirable
2605 that the last_insn, for such purposes, should be the
2606 last insn before computing the return value. Otherwise, cleanups
2607 which call functions can clobber the return value. */
2608 /* ??? rms: I think that is erroneous, because in C++ it would
2609 run destructors on variables that might be used in the subsequent
2610 computation of the return value. */
2612 register rtx val = 0;
2616 struct nesting *block;
2618 /* Bytecode returns are quite simple, just leave the result on the
2619 arithmetic stack. */
2620 if (output_bytecode)
2622 bc_expand_expr (retval);
2623 bc_emit_instruction (ret);
2627 /* If function wants no value, give it none. */
2628 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2630 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2632 expand_null_return ();
2636 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2637 /* This is not sufficient. We also need to watch for cleanups of the
2638 expression we are about to expand. Unfortunately, we cannot know
2639 if it has cleanups until we expand it, and we want to change how we
2640 expand it depending upon if we need cleanups. We can't win. */
2642 cleanups = any_pending_cleanups (1);
2647 if (TREE_CODE (retval) == RESULT_DECL)
2648 retval_rhs = retval;
2649 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2650 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2651 retval_rhs = TREE_OPERAND (retval, 1);
2652 else if (TREE_TYPE (retval) == void_type_node)
2653 /* Recognize tail-recursive call to void function. */
2654 retval_rhs = retval;
2656 retval_rhs = NULL_TREE;
2658 /* Only use `last_insn' if there are cleanups which must be run. */
2659 if (cleanups || cleanup_label != 0)
2660 last_insn = get_last_insn ();
2662 /* Distribute return down conditional expr if either of the sides
2663 may involve tail recursion (see test below). This enhances the number
2664 of tail recursions we see. Don't do this always since it can produce
2665 sub-optimal code in some cases and we distribute assignments into
2666 conditional expressions when it would help. */
2668 if (optimize && retval_rhs != 0
2669 && frame_offset == 0
2670 && TREE_CODE (retval_rhs) == COND_EXPR
2671 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2672 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2674 rtx label = gen_label_rtx ();
2677 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2678 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2679 DECL_RESULT (current_function_decl),
2680 TREE_OPERAND (retval_rhs, 1));
2681 TREE_SIDE_EFFECTS (expr) = 1;
2682 expand_return (expr);
2685 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2686 DECL_RESULT (current_function_decl),
2687 TREE_OPERAND (retval_rhs, 2));
2688 TREE_SIDE_EFFECTS (expr) = 1;
2689 expand_return (expr);
2693 /* For tail-recursive call to current function,
2694 just jump back to the beginning.
2695 It's unsafe if any auto variable in this function
2696 has its address taken; for simplicity,
2697 require stack frame to be empty. */
2698 if (optimize && retval_rhs != 0
2699 && frame_offset == 0
2700 && TREE_CODE (retval_rhs) == CALL_EXPR
2701 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2702 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2703 /* Finish checking validity, and if valid emit code
2704 to set the argument variables for the new call. */
2705 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2706 DECL_ARGUMENTS (current_function_decl)))
2708 if (tail_recursion_label == 0)
2710 tail_recursion_label = gen_label_rtx ();
2711 emit_label_after (tail_recursion_label,
2712 tail_recursion_reentry);
2715 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2720 /* This optimization is safe if there are local cleanups
2721 because expand_null_return takes care of them.
2722 ??? I think it should also be safe when there is a cleanup label,
2723 because expand_null_return takes care of them, too.
2724 Any reason why not? */
2725 if (HAVE_return && cleanup_label == 0
2726 && ! current_function_returns_pcc_struct
2727 && BRANCH_COST <= 1)
2729 /* If this is return x == y; then generate
2730 if (x == y) return 1; else return 0;
2731 if we can do it with explicit return insns and
2732 branches are cheap. */
2734 switch (TREE_CODE (retval_rhs))
2742 case TRUTH_ANDIF_EXPR:
2743 case TRUTH_ORIF_EXPR:
2744 case TRUTH_AND_EXPR:
2746 case TRUTH_NOT_EXPR:
2747 case TRUTH_XOR_EXPR:
2748 op0 = gen_label_rtx ();
2749 jumpifnot (retval_rhs, op0);
2750 expand_value_return (const1_rtx);
2752 expand_value_return (const0_rtx);
2756 #endif /* HAVE_return */
2758 /* If the result is an aggregate that is being returned in one (or more)
2759 registers, load the registers here. The compiler currently can't handle
2760 copying a BLKmode value into registers. We could put this code in a
2761 more general area (for use by everyone instead of just function
2762 call/return), but until this feature is generally usable it is kept here
2763 (and in expand_call). The value must go into a pseudo in case there
2764 are cleanups that will clobber the real return register. */
2767 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2768 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2770 int i, bitpos, xbitpos;
2771 int big_endian_correction = 0;
2772 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2773 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2774 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2775 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2776 rtx result_reg, src, dst;
2777 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2778 enum machine_mode tmpmode, result_reg_mode;
2780 /* Structures whose size is not a multiple of a word are aligned
2781 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2782 machine, this means we must skip the empty high order bytes when
2783 calculating the bit offset. */
2784 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2785 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2788 /* Copy the structure BITSIZE bits at a time. */
2789 for (bitpos = 0, xbitpos = big_endian_correction;
2790 bitpos < bytes * BITS_PER_UNIT;
2791 bitpos += bitsize, xbitpos += bitsize)
2793 /* We need a new destination pseudo each time xbitpos is
2794 on a word boundary and when xbitpos == big_endian_correction
2795 (the first time through). */
2796 if (xbitpos % BITS_PER_WORD == 0
2797 || xbitpos == big_endian_correction)
2799 /* Generate an appropriate register. */
2800 dst = gen_reg_rtx (word_mode);
2801 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2803 /* Clobber the destination before we move anything into it. */
2804 emit_insn (gen_rtx (CLOBBER, VOIDmode, dst));
2807 /* We need a new source operand each time bitpos is on a word
2809 if (bitpos % BITS_PER_WORD == 0)
2810 src = operand_subword_force (result_val,
2811 bitpos / BITS_PER_WORD,
2814 /* Use bitpos for the source extraction (left justified) and
2815 xbitpos for the destination store (right justified). */
2816 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2817 extract_bit_field (src, bitsize,
2818 bitpos % BITS_PER_WORD, 1,
2819 NULL_RTX, word_mode,
2821 bitsize / BITS_PER_UNIT,
2823 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2826 /* Find the smallest integer mode large enough to hold the
2827 entire structure and use that mode instead of BLKmode
2828 on the USE insn for the return register. */
2829 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2830 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2831 tmpmode != MAX_MACHINE_MODE;
2832 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2834 /* Have we found a large enough mode? */
2835 if (GET_MODE_SIZE (tmpmode) >= bytes)
2839 /* No suitable mode found. */
2840 if (tmpmode == MAX_MACHINE_MODE)
2843 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2845 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2846 result_reg_mode = word_mode;
2848 result_reg_mode = tmpmode;
2849 result_reg = gen_reg_rtx (result_reg_mode);
2851 /* Now that the value is in pseudos, copy it to the result reg(s). */
2854 for (i = 0; i < n_regs; i++)
2855 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2858 if (tmpmode != result_reg_mode)
2859 result_reg = gen_lowpart (tmpmode, result_reg);
2861 expand_value_return (result_reg);
2865 && TREE_TYPE (retval_rhs) != void_type_node
2866 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2868 /* Calculate the return value into a pseudo reg. */
2869 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2871 /* All temporaries have now been used. */
2873 /* Return the calculated value, doing cleanups first. */
2874 expand_value_return (val);
2878 /* No cleanups or no hard reg used;
2879 calculate value into hard return reg. */
2880 expand_expr (retval, const0_rtx, VOIDmode, 0);
2883 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2887 /* Return 1 if the end of the generated RTX is not a barrier.
2888 This means code already compiled can drop through. */
2891 drop_through_at_end_p ()
2893 rtx insn = get_last_insn ();
2894 while (insn && GET_CODE (insn) == NOTE)
2895 insn = PREV_INSN (insn);
2896 return insn && GET_CODE (insn) != BARRIER;
2899 /* Emit code to alter this function's formal parms for a tail-recursive call.
2900 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2901 FORMALS is the chain of decls of formals.
2902 Return 1 if this can be done;
2903 otherwise return 0 and do not emit any code. */
2906 tail_recursion_args (actuals, formals)
2907 tree actuals, formals;
2909 register tree a = actuals, f = formals;
2911 register rtx *argvec;
2913 /* Check that number and types of actuals are compatible
2914 with the formals. This is not always true in valid C code.
2915 Also check that no formal needs to be addressable
2916 and that all formals are scalars. */
2918 /* Also count the args. */
2920 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2922 if (TREE_TYPE (TREE_VALUE (a)) != TREE_TYPE (f))
2924 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2927 if (a != 0 || f != 0)
2930 /* Compute all the actuals. */
2932 argvec = (rtx *) alloca (i * sizeof (rtx));
2934 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2935 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2937 /* Find which actual values refer to current values of previous formals.
2938 Copy each of them now, before any formal is changed. */
2940 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2944 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2945 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2946 { copy = 1; break; }
2948 argvec[i] = copy_to_reg (argvec[i]);
2951 /* Store the values of the actuals into the formals. */
2953 for (f = formals, a = actuals, i = 0; f;
2954 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2956 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2957 emit_move_insn (DECL_RTL (f), argvec[i]);
2959 convert_move (DECL_RTL (f), argvec[i],
2960 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2967 /* Generate the RTL code for entering a binding contour.
2968 The variables are declared one by one, by calls to `expand_decl'.
2970 EXIT_FLAG is nonzero if this construct should be visible to
2971 `exit_something'. */
2974 expand_start_bindings (exit_flag)
2977 struct nesting *thisblock = ALLOC_NESTING ();
2978 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2980 /* Make an entry on block_stack for the block we are entering. */
2982 thisblock->next = block_stack;
2983 thisblock->all = nesting_stack;
2984 thisblock->depth = ++nesting_depth;
2985 thisblock->data.block.stack_level = 0;
2986 thisblock->data.block.cleanups = 0;
2987 thisblock->data.block.function_call_count = 0;
2991 if (block_stack->data.block.cleanups == NULL_TREE
2992 && (block_stack->data.block.outer_cleanups == NULL_TREE
2993 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2994 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2996 thisblock->data.block.outer_cleanups
2997 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2998 block_stack->data.block.outer_cleanups);
3001 thisblock->data.block.outer_cleanups = 0;
3005 && !(block_stack->data.block.cleanups == NULL_TREE
3006 && block_stack->data.block.outer_cleanups == NULL_TREE))
3007 thisblock->data.block.outer_cleanups
3008 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3009 block_stack->data.block.outer_cleanups);
3011 thisblock->data.block.outer_cleanups = 0;
3013 thisblock->data.block.label_chain = 0;
3014 thisblock->data.block.innermost_stack_block = stack_block_stack;
3015 thisblock->data.block.first_insn = note;
3016 thisblock->data.block.block_start_count = ++block_start_count;
3017 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3018 block_stack = thisblock;
3019 nesting_stack = thisblock;
3021 if (!output_bytecode)
3023 /* Make a new level for allocating stack slots. */
3028 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3029 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3033 remember_end_note (block)
3034 register tree block;
3036 BLOCK_END_NOTE (block) = last_block_end_note;
3037 last_block_end_note = NULL_RTX;
3040 /* Generate RTL code to terminate a binding contour.
3041 VARS is the chain of VAR_DECL nodes
3042 for the variables bound in this contour.
3043 MARK_ENDS is nonzero if we should put a note at the beginning
3044 and end of this binding contour.
3046 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3047 (That is true automatically if the contour has a saved stack level.) */
3050 expand_end_bindings (vars, mark_ends, dont_jump_in)
3055 register struct nesting *thisblock = block_stack;
3058 if (output_bytecode)
3060 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
3065 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3066 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
3067 && ! DECL_IN_SYSTEM_HEADER (decl))
3068 warning_with_decl (decl, "unused variable `%s'");
3070 if (thisblock->exit_label)
3072 do_pending_stack_adjust ();
3073 emit_label (thisblock->exit_label);
3076 /* If necessary, make a handler for nonlocal gotos taking
3077 place in the function calls in this block. */
3078 if (function_call_count != thisblock->data.block.function_call_count
3080 /* Make handler for outermost block
3081 if there were any nonlocal gotos to this function. */
3082 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3083 /* Make handler for inner block if it has something
3084 special to do when you jump out of it. */
3085 : (thisblock->data.block.cleanups != 0
3086 || thisblock->data.block.stack_level != 0)))
3089 rtx afterward = gen_label_rtx ();
3090 rtx handler_label = gen_label_rtx ();
3091 rtx save_receiver = gen_reg_rtx (Pmode);
3094 /* Don't let jump_optimize delete the handler. */
3095 LABEL_PRESERVE_P (handler_label) = 1;
3097 /* Record the handler address in the stack slot for that purpose,
3098 during this block, saving and restoring the outer value. */
3099 if (thisblock->next != 0)
3101 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3104 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3105 insns = get_insns ();
3107 emit_insns_before (insns, thisblock->data.block.first_insn);
3111 emit_move_insn (nonlocal_goto_handler_slot,
3112 gen_rtx (LABEL_REF, Pmode, handler_label));
3113 insns = get_insns ();
3115 emit_insns_before (insns, thisblock->data.block.first_insn);
3117 /* Jump around the handler; it runs only when specially invoked. */
3118 emit_jump (afterward);
3119 emit_label (handler_label);
3121 #ifdef HAVE_nonlocal_goto
3122 if (! HAVE_nonlocal_goto)
3124 /* First adjust our frame pointer to its actual value. It was
3125 previously set to the start of the virtual area corresponding to
3126 the stacked variables when we branched here and now needs to be
3127 adjusted to the actual hardware fp value.
3129 Assignments are to virtual registers are converted by
3130 instantiate_virtual_regs into the corresponding assignment
3131 to the underlying register (fp in this case) that makes
3132 the original assignment true.
3133 So the following insn will actually be
3134 decrementing fp by STARTING_FRAME_OFFSET. */
3135 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3137 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3138 if (fixed_regs[ARG_POINTER_REGNUM])
3140 #ifdef ELIMINABLE_REGS
3141 /* If the argument pointer can be eliminated in favor of the
3142 frame pointer, we don't need to restore it. We assume here
3143 that if such an elimination is present, it can always be used.
3144 This is the case on all known machines; if we don't make this
3145 assumption, we do unnecessary saving on many machines. */
3146 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3149 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3150 if (elim_regs[i].from == ARG_POINTER_REGNUM
3151 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3154 if (i == sizeof elim_regs / sizeof elim_regs [0])
3157 /* Now restore our arg pointer from the address at which it
3158 was saved in our stack frame.
3159 If there hasn't be space allocated for it yet, make
3161 if (arg_pointer_save_area == 0)
3162 arg_pointer_save_area
3163 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3164 emit_move_insn (virtual_incoming_args_rtx,
3165 /* We need a pseudo here, or else
3166 instantiate_virtual_regs_1 complains. */
3167 copy_to_reg (arg_pointer_save_area));
3172 /* The handler expects the desired label address in the static chain
3173 register. It tests the address and does an appropriate jump
3174 to whatever label is desired. */
3175 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3176 /* Skip any labels we shouldn't be able to jump to from here. */
3177 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3179 rtx not_this = gen_label_rtx ();
3180 rtx this = gen_label_rtx ();
3181 do_jump_if_equal (static_chain_rtx,
3182 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3184 emit_jump (not_this);
3186 expand_goto (TREE_VALUE (link));
3187 emit_label (not_this);
3189 /* If label is not recognized, abort. */
3190 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3193 emit_label (afterward);
3196 /* Don't allow jumping into a block that has cleanups or a stack level. */
3198 || thisblock->data.block.stack_level != 0
3199 || thisblock->data.block.cleanups != 0)
3201 struct label_chain *chain;
3203 /* Any labels in this block are no longer valid to go to.
3204 Mark them to cause an error message. */
3205 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3207 DECL_TOO_LATE (chain->label) = 1;
3208 /* If any goto without a fixup came to this label,
3209 that must be an error, because gotos without fixups
3210 come from outside all saved stack-levels and all cleanups. */
3211 if (TREE_ADDRESSABLE (chain->label))
3212 error_with_decl (chain->label,
3213 "label `%s' used before containing binding contour");
3217 /* Restore stack level in effect before the block
3218 (only if variable-size objects allocated). */
3219 /* Perform any cleanups associated with the block. */
3221 if (thisblock->data.block.stack_level != 0
3222 || thisblock->data.block.cleanups != 0)
3224 /* Only clean up here if this point can actually be reached. */
3225 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3227 /* Don't let cleanups affect ({...}) constructs. */
3228 int old_expr_stmts_for_value = expr_stmts_for_value;
3229 rtx old_last_expr_value = last_expr_value;
3230 tree old_last_expr_type = last_expr_type;
3231 expr_stmts_for_value = 0;
3233 /* Do the cleanups. */
3234 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3236 do_pending_stack_adjust ();
3238 expr_stmts_for_value = old_expr_stmts_for_value;
3239 last_expr_value = old_last_expr_value;
3240 last_expr_type = old_last_expr_type;
3242 /* Restore the stack level. */
3244 if (reachable && thisblock->data.block.stack_level != 0)
3246 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3247 thisblock->data.block.stack_level, NULL_RTX);
3248 if (nonlocal_goto_handler_slot != 0)
3249 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3253 /* Any gotos out of this block must also do these things.
3254 Also report any gotos with fixups that came to labels in this
3256 fixup_gotos (thisblock,
3257 thisblock->data.block.stack_level,
3258 thisblock->data.block.cleanups,
3259 thisblock->data.block.first_insn,
3263 /* Mark the beginning and end of the scope if requested.
3264 We do this now, after running cleanups on the variables
3265 just going out of scope, so they are in scope for their cleanups. */
3268 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3270 /* Get rid of the beginning-mark if we don't make an end-mark. */
3271 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3273 /* If doing stupid register allocation, make sure lives of all
3274 register variables declared here extend thru end of scope. */
3277 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3279 rtx rtl = DECL_RTL (decl);
3280 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3284 /* Restore block_stack level for containing block. */
3286 stack_block_stack = thisblock->data.block.innermost_stack_block;
3287 POPSTACK (block_stack);
3289 /* Pop the stack slot nesting and free any slots at this level. */
3294 /* End a binding contour.
3295 VARS is the chain of VAR_DECL nodes for the variables bound
3296 in this contour. MARK_ENDS is nonzer if we should put a note
3297 at the beginning and end of this binding contour.
3298 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3302 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3307 struct nesting *thisbind = nesting_stack;
3311 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3312 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3313 warning_with_decl (decl, "unused variable `%s'");
3315 if (thisbind->exit_label)
3316 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3318 /* Pop block/bindings off stack */
3319 POPSTACK (block_stack);
3322 /* Generate RTL for the automatic variable declaration DECL.
3323 (Other kinds of declarations are simply ignored if seen here.) */
3329 struct nesting *thisblock = block_stack;
3332 if (output_bytecode)
3334 bc_expand_decl (decl, 0);
3338 type = TREE_TYPE (decl);
3340 /* Only automatic variables need any expansion done.
3341 Static and external variables, and external functions,
3342 will be handled by `assemble_variable' (called from finish_decl).
3343 TYPE_DECL and CONST_DECL require nothing.
3344 PARM_DECLs are handled in `assign_parms'. */
3346 if (TREE_CODE (decl) != VAR_DECL)
3348 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3351 /* Create the RTL representation for the variable. */
3353 if (type == error_mark_node)
3354 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3355 else if (DECL_SIZE (decl) == 0)
3356 /* Variable with incomplete type. */
3358 if (DECL_INITIAL (decl) == 0)
3359 /* Error message was already done; now avoid a crash. */
3360 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3362 /* An initializer is going to decide the size of this array.
3363 Until we know the size, represent its address with a reg. */
3364 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3365 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3367 else if (DECL_MODE (decl) != BLKmode
3368 /* If -ffloat-store, don't put explicit float vars
3370 && !(flag_float_store
3371 && TREE_CODE (type) == REAL_TYPE)
3372 && ! TREE_THIS_VOLATILE (decl)
3373 && ! TREE_ADDRESSABLE (decl)
3374 && (DECL_REGISTER (decl) || ! obey_regdecls))
3376 /* Automatic variable that can go in a register. */
3377 int unsignedp = TREE_UNSIGNED (type);
3378 enum machine_mode reg_mode
3379 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3381 if (TREE_CODE (type) == COMPLEX_TYPE)
3383 rtx realpart, imagpart;
3384 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3386 /* For a complex type variable, make a CONCAT of two pseudos
3387 so that the real and imaginary parts
3388 can be allocated separately. */
3389 realpart = gen_reg_rtx (partmode);
3390 REG_USERVAR_P (realpart) = 1;
3391 imagpart = gen_reg_rtx (partmode);
3392 REG_USERVAR_P (imagpart) = 1;
3393 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3397 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3398 if (TREE_CODE (type) == POINTER_TYPE)
3399 mark_reg_pointer (DECL_RTL (decl));
3400 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3403 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3405 /* Variable of fixed size that goes on the stack. */
3409 /* If we previously made RTL for this decl, it must be an array
3410 whose size was determined by the initializer.
3411 The old address was a register; set that register now
3412 to the proper address. */
3413 if (DECL_RTL (decl) != 0)
3415 if (GET_CODE (DECL_RTL (decl)) != MEM
3416 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3418 oldaddr = XEXP (DECL_RTL (decl), 0);
3422 = assign_stack_temp (DECL_MODE (decl),
3423 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3424 + BITS_PER_UNIT - 1)
3427 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3429 /* Set alignment we actually gave this decl. */
3430 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3431 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3435 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3436 if (addr != oldaddr)
3437 emit_move_insn (oldaddr, addr);
3440 /* If this is a memory ref that contains aggregate components,
3441 mark it as such for cse and loop optimize. */
3442 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3444 /* If this is in memory because of -ffloat-store,
3445 set the volatile bit, to prevent optimizations from
3446 undoing the effects. */
3447 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3448 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3452 /* Dynamic-size object: must push space on the stack. */
3456 /* Record the stack pointer on entry to block, if have
3457 not already done so. */
3458 if (thisblock->data.block.stack_level == 0)
3460 do_pending_stack_adjust ();
3461 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3462 &thisblock->data.block.stack_level,
3463 thisblock->data.block.first_insn);
3464 stack_block_stack = thisblock;
3467 /* Compute the variable's size, in bytes. */
3468 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3470 size_int (BITS_PER_UNIT)),
3471 NULL_RTX, VOIDmode, 0);
3474 /* Allocate space on the stack for the variable. */
3475 address = allocate_dynamic_stack_space (size, NULL_RTX,
3478 /* Reference the variable indirect through that rtx. */
3479 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3481 /* If this is a memory ref that contains aggregate components,
3482 mark it as such for cse and loop optimize. */
3483 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3485 /* Indicate the alignment we actually gave this variable. */
3486 #ifdef STACK_BOUNDARY
3487 DECL_ALIGN (decl) = STACK_BOUNDARY;
3489 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3493 if (TREE_THIS_VOLATILE (decl))
3494 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3495 #if 0 /* A variable is not necessarily unchanging
3496 just because it is const. RTX_UNCHANGING_P
3497 means no change in the function,
3498 not merely no change in the variable's scope.
3499 It is correct to set RTX_UNCHANGING_P if the variable's scope
3500 is the whole function. There's no convenient way to test that. */
3501 if (TREE_READONLY (decl))
3502 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3505 /* If doing stupid register allocation, make sure life of any
3506 register variable starts here, at the start of its scope. */
3509 use_variable (DECL_RTL (decl));
3513 /* Generate code for the automatic variable declaration DECL. For
3514 most variables this just means we give it a stack offset. The
3515 compiler sometimes emits cleanups without variables and we will
3516 have to deal with those too. */
3519 bc_expand_decl (decl, cleanup)
3527 /* A cleanup with no variable. */
3534 /* Only auto variables need any work. */
3535 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3538 type = TREE_TYPE (decl);
3540 if (type == error_mark_node)
3541 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3543 else if (DECL_SIZE (decl) == 0)
3545 /* Variable with incomplete type. The stack offset herein will be
3546 fixed later in expand_decl_init (). */
3547 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3549 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3551 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3555 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3558 /* Emit code to perform the initialization of a declaration DECL. */
3561 expand_decl_init (decl)
3564 int was_used = TREE_USED (decl);
3566 if (output_bytecode)
3568 bc_expand_decl_init (decl);
3572 /* If this is a CONST_DECL, we don't have to generate any code, but
3573 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3574 to be set while in the obstack containing the constant. If we don't
3575 do this, we can lose if we have functions nested three deep and the middle
3576 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3577 the innermost function is the first to expand that STRING_CST. */
3578 if (TREE_CODE (decl) == CONST_DECL)
3580 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3581 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3582 EXPAND_INITIALIZER);
3586 if (TREE_STATIC (decl))
3589 /* Compute and store the initial value now. */
3591 if (DECL_INITIAL (decl) == error_mark_node)
3593 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3594 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3595 || code == POINTER_TYPE)
3596 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3600 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3602 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3603 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3607 /* Don't let the initialization count as "using" the variable. */
3608 TREE_USED (decl) = was_used;
3610 /* Free any temporaries we made while initializing the decl. */
3611 preserve_temp_slots (NULL_RTX);
3615 /* Expand initialization for variable-sized types. Allocate array
3616 using newlocalSI and set local variable, which is a pointer to the
3620 bc_expand_variable_local_init (decl)
3623 /* Evaluate size expression and coerce to SI */
3624 bc_expand_expr (DECL_SIZE (decl));
3626 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3627 no coercion is necessary (?) */
3629 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3630 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3632 /* Emit code to allocate array */
3633 bc_emit_instruction (newlocalSI);
3635 /* Store array pointer in local variable. This is the only instance
3636 where we actually want the address of the pointer to the
3637 variable-size block, rather than the pointer itself. We avoid
3638 using expand_address() since that would cause the pointer to be
3639 pushed rather than its address. Hence the hard-coded reference;
3640 notice also that the variable is always local (no global
3641 variable-size type variables). */
3643 bc_load_localaddr (DECL_RTL (decl));
3644 bc_emit_instruction (storeP);
3648 /* Emit code to initialize a declaration. */
3651 bc_expand_decl_init (decl)
3654 int org_stack_depth;
3656 /* Statical initializers are handled elsewhere */
3658 if (TREE_STATIC (decl))
3661 /* Memory original stack depth */
3662 org_stack_depth = stack_depth;
3664 /* If the type is variable-size, we first create its space (we ASSUME
3665 it CAN'T be static). We do this regardless of whether there's an
3666 initializer assignment or not. */
3668 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3669 bc_expand_variable_local_init (decl);
3671 /* Expand initializer assignment */
3672 if (DECL_INITIAL (decl) == error_mark_node)
3674 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3676 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3677 || code == POINTER_TYPE)
3679 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3681 else if (DECL_INITIAL (decl))
3682 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3684 /* Restore stack depth */
3685 if (org_stack_depth > stack_depth)
3688 bc_adjust_stack (stack_depth - org_stack_depth);
3692 /* CLEANUP is an expression to be executed at exit from this binding contour;
3693 for example, in C++, it might call the destructor for this variable.
3695 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3696 either before or after calling `expand_decl_cleanup' but before compiling
3697 any subsequent expressions. This is because CLEANUP may be expanded
3698 more than once, on different branches of execution.
3699 For the same reason, CLEANUP may not contain a CALL_EXPR
3700 except as its topmost node--else `preexpand_calls' would get confused.
3702 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3703 that is not associated with any particular variable. */
3706 expand_decl_cleanup (decl, cleanup)
3709 struct nesting *thisblock = block_stack;
3711 /* Error if we are not in any block. */
3715 /* Record the cleanup if there is one. */
3719 thisblock->data.block.cleanups
3720 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3721 /* If this block has a cleanup, it belongs in stack_block_stack. */
3722 stack_block_stack = thisblock;
3723 (*interim_eh_hook) (NULL_TREE);
3728 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3729 DECL_ELTS is the list of elements that belong to DECL's type.
3730 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3733 expand_anon_union_decl (decl, cleanup, decl_elts)
3734 tree decl, cleanup, decl_elts;
3736 struct nesting *thisblock = block_stack;
3740 expand_decl_cleanup (decl, cleanup);
3741 x = DECL_RTL (decl);
3745 tree decl_elt = TREE_VALUE (decl_elts);
3746 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3747 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3749 /* Propagate the union's alignment to the elements. */
3750 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3752 /* If the element has BLKmode and the union doesn't, the union is
3753 aligned such that the element doesn't need to have BLKmode, so
3754 change the element's mode to the appropriate one for its size. */
3755 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3756 DECL_MODE (decl_elt) = mode
3757 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3760 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3761 instead create a new MEM rtx with the proper mode. */
3762 if (GET_CODE (x) == MEM)
3764 if (mode == GET_MODE (x))
3765 DECL_RTL (decl_elt) = x;
3768 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3769 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3770 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3773 else if (GET_CODE (x) == REG)
3775 if (mode == GET_MODE (x))
3776 DECL_RTL (decl_elt) = x;
3778 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3783 /* Record the cleanup if there is one. */
3786 thisblock->data.block.cleanups
3787 = temp_tree_cons (decl_elt, cleanup_elt,
3788 thisblock->data.block.cleanups);
3790 decl_elts = TREE_CHAIN (decl_elts);
3794 /* Expand a list of cleanups LIST.
3795 Elements may be expressions or may be nested lists.
3797 If DONT_DO is nonnull, then any list-element
3798 whose TREE_PURPOSE matches DONT_DO is omitted.
3799 This is sometimes used to avoid a cleanup associated with
3800 a value that is being returned out of the scope.
3802 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3803 goto and handle protection regions specially in that case.
3805 If REACHABLE, we emit code, otherwise just inform the exception handling
3806 code about this finalization. */
3809 expand_cleanups (list, dont_do, in_fixup, reachable)
3816 for (tail = list; tail; tail = TREE_CHAIN (tail))
3817 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3819 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3820 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3824 (*interim_eh_hook) (TREE_VALUE (tail));
3828 /* Cleanups may be run multiple times. For example,
3829 when exiting a binding contour, we expand the
3830 cleanups associated with that contour. When a goto
3831 within that binding contour has a target outside that
3832 contour, it will expand all cleanups from its scope to
3833 the target. Though the cleanups are expanded multiple
3834 times, the control paths are non-overlapping so the
3835 cleanups will not be executed twice. */
3836 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3843 /* Move all cleanups from the current block_stack
3844 to the containing block_stack, where they are assumed to
3845 have been created. If anything can cause a temporary to
3846 be created, but not expanded for more than one level of
3847 block_stacks, then this code will have to change. */
3852 struct nesting *block = block_stack;
3853 struct nesting *outer = block->next;
3855 outer->data.block.cleanups
3856 = chainon (block->data.block.cleanups,
3857 outer->data.block.cleanups);
3858 block->data.block.cleanups = 0;
3862 last_cleanup_this_contour ()
3864 if (block_stack == 0)
3867 return block_stack->data.block.cleanups;
3870 /* Return 1 if there are any pending cleanups at this point.
3871 If THIS_CONTOUR is nonzero, check the current contour as well.
3872 Otherwise, look only at the contours that enclose this one. */
3875 any_pending_cleanups (this_contour)
3878 struct nesting *block;
3880 if (block_stack == 0)
3883 if (this_contour && block_stack->data.block.cleanups != NULL)
3885 if (block_stack->data.block.cleanups == 0
3886 && (block_stack->data.block.outer_cleanups == 0
3888 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3893 for (block = block_stack->next; block; block = block->next)
3894 if (block->data.block.cleanups != 0)
3900 /* Enter a case (Pascal) or switch (C) statement.
3901 Push a block onto case_stack and nesting_stack
3902 to accumulate the case-labels that are seen
3903 and to record the labels generated for the statement.
3905 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3906 Otherwise, this construct is transparent for `exit_something'.
3908 EXPR is the index-expression to be dispatched on.
3909 TYPE is its nominal type. We could simply convert EXPR to this type,
3910 but instead we take short cuts. */
3913 expand_start_case (exit_flag, expr, type, printname)
3919 register struct nesting *thiscase = ALLOC_NESTING ();
3921 /* Make an entry on case_stack for the case we are entering. */
3923 thiscase->next = case_stack;
3924 thiscase->all = nesting_stack;
3925 thiscase->depth = ++nesting_depth;
3926 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3927 thiscase->data.case_stmt.case_list = 0;
3928 thiscase->data.case_stmt.index_expr = expr;
3929 thiscase->data.case_stmt.nominal_type = type;
3930 thiscase->data.case_stmt.default_label = 0;
3931 thiscase->data.case_stmt.num_ranges = 0;
3932 thiscase->data.case_stmt.printname = printname;
3933 thiscase->data.case_stmt.seenlabel = 0;
3934 case_stack = thiscase;
3935 nesting_stack = thiscase;
3937 if (output_bytecode)
3939 bc_expand_start_case (thiscase, expr, type, printname);
3943 do_pending_stack_adjust ();
3945 /* Make sure case_stmt.start points to something that won't
3946 need any transformation before expand_end_case. */
3947 if (GET_CODE (get_last_insn ()) != NOTE)
3948 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3950 thiscase->data.case_stmt.start = get_last_insn ();
3954 /* Enter a case statement. It is assumed that the caller has pushed
3955 the current context onto the case stack. */
3958 bc_expand_start_case (thiscase, expr, type, printname)
3959 struct nesting *thiscase;
3964 bc_expand_expr (expr);
3965 bc_expand_conversion (TREE_TYPE (expr), type);
3967 /* For cases, the skip is a place we jump to that's emitted after
3968 the size of the jump table is known. */
3970 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3971 bc_emit_bytecode (jump);
3972 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3974 #ifdef DEBUG_PRINT_CODE
3975 fputc ('\n', stderr);
3980 /* Start a "dummy case statement" within which case labels are invalid
3981 and are not connected to any larger real case statement.
3982 This can be used if you don't want to let a case statement jump
3983 into the middle of certain kinds of constructs. */
3986 expand_start_case_dummy ()
3988 register struct nesting *thiscase = ALLOC_NESTING ();
3990 /* Make an entry on case_stack for the dummy. */
3992 thiscase->next = case_stack;
3993 thiscase->all = nesting_stack;
3994 thiscase->depth = ++nesting_depth;
3995 thiscase->exit_label = 0;
3996 thiscase->data.case_stmt.case_list = 0;
3997 thiscase->data.case_stmt.start = 0;
3998 thiscase->data.case_stmt.nominal_type = 0;
3999 thiscase->data.case_stmt.default_label = 0;
4000 thiscase->data.case_stmt.num_ranges = 0;
4001 case_stack = thiscase;
4002 nesting_stack = thiscase;
4005 /* End a dummy case statement. */
4008 expand_end_case_dummy ()
4010 POPSTACK (case_stack);
4013 /* Return the data type of the index-expression
4014 of the innermost case statement, or null if none. */
4017 case_index_expr_type ()
4020 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4024 /* Accumulate one case or default label inside a case or switch statement.
4025 VALUE is the value of the case (a null pointer, for a default label).
4026 The function CONVERTER, when applied to arguments T and V,
4027 converts the value V to the type T.
4029 If not currently inside a case or switch statement, return 1 and do
4030 nothing. The caller will print a language-specific error message.
4031 If VALUE is a duplicate or overlaps, return 2 and do nothing
4032 except store the (first) duplicate node in *DUPLICATE.
4033 If VALUE is out of range, return 3 and do nothing.
4034 If we are jumping into the scope of a cleaup or var-sized array, return 5.
4035 Return 0 on success.
4037 Extended to handle range statements. */
4040 pushcase (value, converter, label, duplicate)
4041 register tree value;
4042 tree (*converter) PROTO((tree, tree));
4043 register tree label;
4046 register struct case_node **l;
4047 register struct case_node *n;
4051 if (output_bytecode)
4052 return bc_pushcase (value, label);
4054 /* Fail if not inside a real case statement. */
4055 if (! (case_stack && case_stack->data.case_stmt.start))
4058 if (stack_block_stack
4059 && stack_block_stack->depth > case_stack->depth)
4062 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4063 nominal_type = case_stack->data.case_stmt.nominal_type;
4065 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4066 if (index_type == error_mark_node)
4069 /* Convert VALUE to the type in which the comparisons are nominally done. */
4071 value = (*converter) (nominal_type, value);
4073 /* If this is the first label, warn if any insns have been emitted. */
4074 if (case_stack->data.case_stmt.seenlabel == 0)
4077 for (insn = case_stack->data.case_stmt.start;
4079 insn = NEXT_INSN (insn))
4081 if (GET_CODE (insn) == CODE_LABEL)
4083 if (GET_CODE (insn) != NOTE
4084 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4086 warning ("unreachable code at beginning of %s",
4087 case_stack->data.case_stmt.printname);
4092 case_stack->data.case_stmt.seenlabel = 1;
4094 /* Fail if this value is out of range for the actual type of the index
4095 (which may be narrower than NOMINAL_TYPE). */
4096 if (value != 0 && ! int_fits_type_p (value, index_type))
4099 /* Fail if this is a duplicate or overlaps another entry. */
4102 if (case_stack->data.case_stmt.default_label != 0)
4104 *duplicate = case_stack->data.case_stmt.default_label;
4107 case_stack->data.case_stmt.default_label = label;
4111 /* Find the elt in the chain before which to insert the new value,
4112 to keep the chain sorted in increasing order.
4113 But report an error if this element is a duplicate. */
4114 for (l = &case_stack->data.case_stmt.case_list;
4115 /* Keep going past elements distinctly less than VALUE. */
4116 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4121 /* Element we will insert before must be distinctly greater;
4122 overlap means error. */
4123 if (! tree_int_cst_lt (value, (*l)->low))
4125 *duplicate = (*l)->code_label;
4130 /* Add this label to the chain, and succeed.
4131 Copy VALUE so it is on temporary rather than momentary
4132 obstack and will thus survive till the end of the case statement. */
4133 n = (struct case_node *) oballoc (sizeof (struct case_node));
4136 n->high = n->low = copy_node (value);
4137 n->code_label = label;
4141 expand_label (label);
4145 /* Like pushcase but this case applies to all values
4146 between VALUE1 and VALUE2 (inclusive).
4147 The return value is the same as that of pushcase
4148 but there is one additional error code:
4149 4 means the specified range was empty. */
4152 pushcase_range (value1, value2, converter, label, duplicate)
4153 register tree value1, value2;
4154 tree (*converter) PROTO((tree, tree));
4155 register tree label;
4158 register struct case_node **l;
4159 register struct case_node *n;
4163 /* Fail if not inside a real case statement. */
4164 if (! (case_stack && case_stack->data.case_stmt.start))
4167 if (stack_block_stack
4168 && stack_block_stack->depth > case_stack->depth)
4171 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4172 nominal_type = case_stack->data.case_stmt.nominal_type;
4174 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4175 if (index_type == error_mark_node)
4178 /* If this is the first label, warn if any insns have been emitted. */
4179 if (case_stack->data.case_stmt.seenlabel == 0)
4182 for (insn = case_stack->data.case_stmt.start;
4184 insn = NEXT_INSN (insn))
4186 if (GET_CODE (insn) == CODE_LABEL)
4188 if (GET_CODE (insn) != NOTE
4189 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4191 warning ("unreachable code at beginning of %s",
4192 case_stack->data.case_stmt.printname);
4197 case_stack->data.case_stmt.seenlabel = 1;
4199 /* Convert VALUEs to type in which the comparisons are nominally done. */
4200 if (value1 == 0) /* Negative infinity. */
4201 value1 = TYPE_MIN_VALUE(index_type);
4202 value1 = (*converter) (nominal_type, value1);
4204 if (value2 == 0) /* Positive infinity. */
4205 value2 = TYPE_MAX_VALUE(index_type);
4206 value2 = (*converter) (nominal_type, value2);
4208 /* Fail if these values are out of range. */
4209 if (! int_fits_type_p (value1, index_type))
4212 if (! int_fits_type_p (value2, index_type))
4215 /* Fail if the range is empty. */
4216 if (tree_int_cst_lt (value2, value1))
4219 /* If the bounds are equal, turn this into the one-value case. */
4220 if (tree_int_cst_equal (value1, value2))
4221 return pushcase (value1, converter, label, duplicate);
4223 /* Find the elt in the chain before which to insert the new value,
4224 to keep the chain sorted in increasing order.
4225 But report an error if this element is a duplicate. */
4226 for (l = &case_stack->data.case_stmt.case_list;
4227 /* Keep going past elements distinctly less than this range. */
4228 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4233 /* Element we will insert before must be distinctly greater;
4234 overlap means error. */
4235 if (! tree_int_cst_lt (value2, (*l)->low))
4237 *duplicate = (*l)->code_label;
4242 /* Add this label to the chain, and succeed.
4243 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4244 obstack and will thus survive till the end of the case statement. */
4246 n = (struct case_node *) oballoc (sizeof (struct case_node));
4249 n->low = copy_node (value1);
4250 n->high = copy_node (value2);
4251 n->code_label = label;
4254 expand_label (label);
4256 case_stack->data.case_stmt.num_ranges++;
4262 /* Accumulate one case or default label; VALUE is the value of the
4263 case, or nil for a default label. If not currently inside a case,
4264 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4265 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4266 Return 0 on success. This function is a leftover from the earlier
4267 bytecode compiler, which was based on gcc 1.37. It should be
4268 merged into pushcase. */
4271 bc_pushcase (value, label)
4275 struct nesting *thiscase = case_stack;
4276 struct case_node *case_label, *new_label;
4281 /* Fail if duplicate, overlap, or out of type range. */
4284 value = convert (thiscase->data.case_stmt.nominal_type, value);
4285 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4288 for (case_label = thiscase->data.case_stmt.case_list;
4289 case_label->left; case_label = case_label->left)
4290 if (! tree_int_cst_lt (case_label->left->high, value))
4293 if (case_label != thiscase->data.case_stmt.case_list
4294 && ! tree_int_cst_lt (case_label->high, value)
4295 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4298 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4299 new_label->low = new_label->high = copy_node (value);
4300 new_label->code_label = label;
4301 new_label->left = case_label->left;
4303 case_label->left = new_label;
4304 thiscase->data.case_stmt.num_ranges++;
4308 if (thiscase->data.case_stmt.default_label)
4310 thiscase->data.case_stmt.default_label = label;
4313 expand_label (label);
4317 /* Returns the number of possible values of TYPE.
4318 Returns -1 if the number is unknown or variable.
4319 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4320 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4321 do not increase monotonically (there may be duplicates);
4322 to 1 if the values increase monotonically, but not always by 1;
4323 otherwise sets it to 0. */
4326 all_cases_count (type, spareness)
4330 HOST_WIDE_INT count, count_high = 0;
4333 switch (TREE_CODE (type))
4340 count = 1 << BITS_PER_UNIT;
4344 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4345 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4350 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4351 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4352 but with overflow checking. */
4353 tree mint = TYPE_MIN_VALUE (type);
4354 tree maxt = TYPE_MAX_VALUE (type);
4355 HOST_WIDE_INT lo, hi;
4356 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4358 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4360 add_double (lo, hi, 1, 0, &lo, &hi);
4361 if (hi != 0 || lo < 0)
4368 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4370 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4371 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4372 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4373 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4377 if (*spareness == 1)
4379 tree prev = TREE_VALUE (TYPE_VALUES (type));
4380 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4382 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4387 prev = TREE_VALUE (t);
4396 #define BITARRAY_TEST(ARRAY, INDEX) \
4397 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4398 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4399 #define BITARRAY_SET(ARRAY, INDEX) \
4400 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4401 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4403 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4404 with the case values we have seen, assuming the case expression
4406 SPARSENESS is as determined by all_cases_count.
4408 The time needed is proportional to COUNT, unless
4409 SPARSENESS is 2, in which case quadratic time is needed. */
4412 mark_seen_cases (type, cases_seen, count, sparseness)
4414 unsigned char *cases_seen;
4420 tree next_node_to_try = NULL_TREE;
4421 long next_node_offset = 0;
4423 register struct case_node *n;
4424 tree val = make_node (INTEGER_CST);
4425 TREE_TYPE (val) = type;
4426 for (n = case_stack->data.case_stmt.case_list; n;
4429 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4430 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4431 while ( ! tree_int_cst_lt (n->high, val))
4433 /* Calculate (into xlo) the "offset" of the integer (val).
4434 The element with lowest value has offset 0, the next smallest
4435 element has offset 1, etc. */
4437 HOST_WIDE_INT xlo, xhi;
4439 if (sparseness == 2)
4441 /* This less efficient loop is only needed to handle
4442 duplicate case values (multiple enum constants
4443 with the same value). */
4444 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4445 t = TREE_CHAIN (t), xlo++)
4447 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4448 BITARRAY_SET (cases_seen, xlo);
4453 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4455 /* The TYPE_VALUES will be in increasing order, so
4456 starting searching where we last ended. */
4457 t = next_node_to_try;
4458 xlo = next_node_offset;
4464 t = TYPE_VALUES (type);
4467 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4469 next_node_to_try = TREE_CHAIN (t);
4470 next_node_offset = xlo + 1;
4475 if (t == next_node_to_try)
4481 t = TYPE_MIN_VALUE (type);
4483 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4487 add_double (xlo, xhi,
4488 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4492 if (xhi == 0 && xlo >= 0 && xlo < count)
4493 BITARRAY_SET (cases_seen, xlo);
4495 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4497 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4502 /* Called when the index of a switch statement is an enumerated type
4503 and there is no default label.
4505 Checks that all enumeration literals are covered by the case
4506 expressions of a switch. Also, warn if there are any extra
4507 switch cases that are *not* elements of the enumerated type.
4509 If all enumeration literals were covered by the case expressions,
4510 turn one of the expressions into the default expression since it should
4511 not be possible to fall through such a switch. */
4514 check_for_full_enumeration_handling (type)
4517 register struct case_node *n;
4518 register struct case_node **l;
4519 register tree chain;
4522 /* True iff the selector type is a numbered set mode. */
4525 /* The number of possible selector values. */
4528 /* For each possible selector value. a one iff it has been matched
4529 by a case value alternative. */
4530 unsigned char *cases_seen;
4532 /* The allocated size of cases_seen, in chars. */
4536 if (output_bytecode)
4538 bc_check_for_full_enumeration_handling (type);
4545 size = all_cases_count (type, &sparseness);
4546 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4548 if (size > 0 && size < 600000
4549 /* We deliberately use malloc here - not xmalloc. */
4550 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4553 tree v = TYPE_VALUES (type);
4554 bzero (cases_seen, bytes_needed);
4556 /* The time complexity of this code is normally O(N), where
4557 N being the number of members in the enumerated type.
4558 However, if type is a ENUMERAL_TYPE whose values do not
4559 increase monotonically, quadratic time may be needed. */
4561 mark_seen_cases (type, cases_seen, size, sparseness);
4563 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4565 if (BITARRAY_TEST(cases_seen, i) == 0)
4566 warning ("enumeration value `%s' not handled in switch",
4567 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4573 /* Now we go the other way around; we warn if there are case
4574 expressions that don't correspond to enumerators. This can
4575 occur since C and C++ don't enforce type-checking of
4576 assignments to enumeration variables. */
4579 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4581 for (chain = TYPE_VALUES (type);
4582 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4583 chain = TREE_CHAIN (chain))
4588 if (TYPE_NAME (type) == 0)
4589 warning ("case value `%d' not in enumerated type",
4590 TREE_INT_CST_LOW (n->low));
4592 warning ("case value `%d' not in enumerated type `%s'",
4593 TREE_INT_CST_LOW (n->low),
4594 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4597 : DECL_NAME (TYPE_NAME (type))));
4599 if (!tree_int_cst_equal (n->low, n->high))
4601 for (chain = TYPE_VALUES (type);
4602 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4603 chain = TREE_CHAIN (chain))
4608 if (TYPE_NAME (type) == 0)
4609 warning ("case value `%d' not in enumerated type",
4610 TREE_INT_CST_LOW (n->high));
4612 warning ("case value `%d' not in enumerated type `%s'",
4613 TREE_INT_CST_LOW (n->high),
4614 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4617 : DECL_NAME (TYPE_NAME (type))));
4623 /* ??? This optimization is disabled because it causes valid programs to
4624 fail. ANSI C does not guarantee that an expression with enum type
4625 will have a value that is the same as one of the enumeration literals. */
4627 /* If all values were found as case labels, make one of them the default
4628 label. Thus, this switch will never fall through. We arbitrarily pick
4629 the last one to make the default since this is likely the most
4630 efficient choice. */
4634 for (l = &case_stack->data.case_stmt.case_list;
4639 case_stack->data.case_stmt.default_label = (*l)->code_label;
4646 /* Check that all enumeration literals are covered by the case
4647 expressions of a switch. Also warn if there are any cases
4648 that are not elements of the enumerated type. */
4651 bc_check_for_full_enumeration_handling (type)
4654 struct nesting *thiscase = case_stack;
4655 struct case_node *c;
4658 /* Check for enums not handled. */
4659 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4661 for (c = thiscase->data.case_stmt.case_list->left;
4662 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4665 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4666 warning ("enumerated value `%s' not handled in switch",
4667 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4670 /* Check for cases not in the enumeration. */
4671 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4673 for (e = TYPE_VALUES (type);
4674 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4678 warning ("case value `%d' not in enumerated type `%s'",
4679 TREE_INT_CST_LOW (c->low),
4680 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4682 : DECL_NAME (TYPE_NAME (type))));
4686 /* Terminate a case (Pascal) or switch (C) statement
4687 in which ORIG_INDEX is the expression to be tested.
4688 Generate the code to test it and jump to the right place. */
4691 expand_end_case (orig_index)
4694 tree minval, maxval, range, orig_minval;
4695 rtx default_label = 0;
4696 register struct case_node *n;
4704 register struct nesting *thiscase = case_stack;
4705 tree index_expr, index_type;
4708 if (output_bytecode)
4710 bc_expand_end_case (orig_index);
4714 table_label = gen_label_rtx ();
4715 index_expr = thiscase->data.case_stmt.index_expr;
4716 index_type = TREE_TYPE (index_expr);
4717 unsignedp = TREE_UNSIGNED (index_type);
4719 do_pending_stack_adjust ();
4721 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4722 if (index_type != error_mark_node)
4724 /* If switch expression was an enumerated type, check that all
4725 enumeration literals are covered by the cases.
4726 No sense trying this if there's a default case, however. */
4728 if (!thiscase->data.case_stmt.default_label
4729 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4730 && TREE_CODE (index_expr) != INTEGER_CST)
4731 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4733 /* If this is the first label, warn if any insns have been emitted. */
4734 if (thiscase->data.case_stmt.seenlabel == 0)
4737 for (insn = get_last_insn ();
4738 insn != case_stack->data.case_stmt.start;
4739 insn = PREV_INSN (insn))
4740 if (GET_CODE (insn) != NOTE
4741 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4743 warning ("unreachable code at beginning of %s",
4744 case_stack->data.case_stmt.printname);
4749 /* If we don't have a default-label, create one here,
4750 after the body of the switch. */
4751 if (thiscase->data.case_stmt.default_label == 0)
4753 thiscase->data.case_stmt.default_label
4754 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4755 expand_label (thiscase->data.case_stmt.default_label);
4757 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4759 before_case = get_last_insn ();
4761 /* Simplify the case-list before we count it. */
4762 group_case_nodes (thiscase->data.case_stmt.case_list);
4764 /* Get upper and lower bounds of case values.
4765 Also convert all the case values to the index expr's data type. */
4768 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4770 /* Check low and high label values are integers. */
4771 if (TREE_CODE (n->low) != INTEGER_CST)
4773 if (TREE_CODE (n->high) != INTEGER_CST)
4776 n->low = convert (index_type, n->low);
4777 n->high = convert (index_type, n->high);
4779 /* Count the elements and track the largest and smallest
4780 of them (treating them as signed even if they are not). */
4788 if (INT_CST_LT (n->low, minval))
4790 if (INT_CST_LT (maxval, n->high))
4793 /* A range counts double, since it requires two compares. */
4794 if (! tree_int_cst_equal (n->low, n->high))
4798 orig_minval = minval;
4800 /* Compute span of values. */
4802 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4806 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4808 emit_jump (default_label);
4811 /* If range of values is much bigger than number of values,
4812 make a sequence of conditional branches instead of a dispatch.
4813 If the switch-index is a constant, do it this way
4814 because we can optimize it. */
4816 #ifndef CASE_VALUES_THRESHOLD
4818 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4820 /* If machine does not have a case insn that compares the
4821 bounds, this means extra overhead for dispatch tables
4822 which raises the threshold for using them. */
4823 #define CASE_VALUES_THRESHOLD 5
4824 #endif /* HAVE_casesi */
4825 #endif /* CASE_VALUES_THRESHOLD */
4827 else if (TREE_INT_CST_HIGH (range) != 0
4828 || count < CASE_VALUES_THRESHOLD
4829 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4831 || TREE_CODE (index_expr) == INTEGER_CST
4832 /* These will reduce to a constant. */
4833 || (TREE_CODE (index_expr) == CALL_EXPR
4834 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4835 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4836 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4837 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4838 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4840 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4842 /* If the index is a short or char that we do not have
4843 an insn to handle comparisons directly, convert it to
4844 a full integer now, rather than letting each comparison
4845 generate the conversion. */
4847 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4848 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4849 == CODE_FOR_nothing))
4851 enum machine_mode wider_mode;
4852 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4853 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4854 if (cmp_optab->handlers[(int) wider_mode].insn_code
4855 != CODE_FOR_nothing)
4857 index = convert_to_mode (wider_mode, index, unsignedp);
4863 do_pending_stack_adjust ();
4865 index = protect_from_queue (index, 0);
4866 if (GET_CODE (index) == MEM)
4867 index = copy_to_reg (index);
4868 if (GET_CODE (index) == CONST_INT
4869 || TREE_CODE (index_expr) == INTEGER_CST)
4871 /* Make a tree node with the proper constant value
4872 if we don't already have one. */
4873 if (TREE_CODE (index_expr) != INTEGER_CST)
4876 = build_int_2 (INTVAL (index),
4877 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4878 index_expr = convert (index_type, index_expr);
4881 /* For constant index expressions we need only
4882 issue a unconditional branch to the appropriate
4883 target code. The job of removing any unreachable
4884 code is left to the optimisation phase if the
4885 "-O" option is specified. */
4886 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4887 if (! tree_int_cst_lt (index_expr, n->low)
4888 && ! tree_int_cst_lt (n->high, index_expr))
4892 emit_jump (label_rtx (n->code_label));
4894 emit_jump (default_label);
4898 /* If the index expression is not constant we generate
4899 a binary decision tree to select the appropriate
4900 target code. This is done as follows:
4902 The list of cases is rearranged into a binary tree,
4903 nearly optimal assuming equal probability for each case.
4905 The tree is transformed into RTL, eliminating
4906 redundant test conditions at the same time.
4908 If program flow could reach the end of the
4909 decision tree an unconditional jump to the
4910 default code is emitted. */
4913 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4914 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4915 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4917 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4918 default_label, index_type);
4919 emit_jump_if_reachable (default_label);
4928 enum machine_mode index_mode = SImode;
4929 int index_bits = GET_MODE_BITSIZE (index_mode);
4931 enum machine_mode op_mode;
4933 /* Convert the index to SImode. */
4934 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4935 > GET_MODE_BITSIZE (index_mode))
4937 enum machine_mode omode = TYPE_MODE (index_type);
4938 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4940 /* We must handle the endpoints in the original mode. */
4941 index_expr = build (MINUS_EXPR, index_type,
4942 index_expr, minval);
4943 minval = integer_zero_node;
4944 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4945 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4946 emit_jump_insn (gen_bltu (default_label));
4947 /* Now we can safely truncate. */
4948 index = convert_to_mode (index_mode, index, 0);
4952 if (TYPE_MODE (index_type) != index_mode)
4954 index_expr = convert (type_for_size (index_bits, 0),
4956 index_type = TREE_TYPE (index_expr);
4959 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4962 index = protect_from_queue (index, 0);
4963 do_pending_stack_adjust ();
4965 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4966 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4968 index = copy_to_mode_reg (op_mode, index);
4970 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4972 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4973 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4975 op1 = copy_to_mode_reg (op_mode, op1);
4977 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4979 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4980 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4982 op2 = copy_to_mode_reg (op_mode, op2);
4984 emit_jump_insn (gen_casesi (index, op1, op2,
4985 table_label, default_label));
4989 #ifdef HAVE_tablejump
4990 if (! win && HAVE_tablejump)
4992 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4993 fold (build (MINUS_EXPR, index_type,
4994 index_expr, minval)));
4995 index_type = TREE_TYPE (index_expr);
4996 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4998 index = protect_from_queue (index, 0);
4999 do_pending_stack_adjust ();
5001 do_tablejump (index, TYPE_MODE (index_type),
5002 expand_expr (range, NULL_RTX, VOIDmode, 0),
5003 table_label, default_label);
5010 /* Get table of labels to jump to, in order of case index. */
5012 ncases = TREE_INT_CST_LOW (range) + 1;
5013 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5014 bzero ((char *) labelvec, ncases * sizeof (rtx));
5016 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5018 register HOST_WIDE_INT i
5019 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5024 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
5025 if (i + TREE_INT_CST_LOW (orig_minval)
5026 == TREE_INT_CST_LOW (n->high))
5032 /* Fill in the gaps with the default. */
5033 for (i = 0; i < ncases; i++)
5034 if (labelvec[i] == 0)
5035 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
5037 /* Output the table */
5038 emit_label (table_label);
5040 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
5041 were an expression, instead of an #ifdef/#ifndef. */
5043 #ifdef CASE_VECTOR_PC_RELATIVE
5047 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
5048 gen_rtx (LABEL_REF, Pmode, table_label),
5049 gen_rtvec_v (ncases, labelvec)));
5051 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
5052 gen_rtvec_v (ncases, labelvec)));
5054 /* If the case insn drops through the table,
5055 after the table we must jump to the default-label.
5056 Otherwise record no drop-through after the table. */
5057 #ifdef CASE_DROPS_THROUGH
5058 emit_jump (default_label);
5064 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5065 reorder_insns (before_case, get_last_insn (),
5066 thiscase->data.case_stmt.start);
5069 if (thiscase->exit_label)
5070 emit_label (thiscase->exit_label);
5072 POPSTACK (case_stack);
5078 /* Terminate a case statement. EXPR is the original index
5082 bc_expand_end_case (expr)
5085 struct nesting *thiscase = case_stack;
5086 enum bytecode_opcode opcode;
5087 struct bc_label *jump_label;
5088 struct case_node *c;
5090 bc_emit_bytecode (jump);
5091 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5093 #ifdef DEBUG_PRINT_CODE
5094 fputc ('\n', stderr);
5097 /* Now that the size of the jump table is known, emit the actual
5098 indexed jump instruction. */
5099 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5101 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5102 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5103 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5105 bc_emit_bytecode (opcode);
5107 /* Now emit the case instructions literal arguments, in order.
5108 In addition to the value on the stack, it uses:
5109 1. The address of the jump table.
5110 2. The size of the jump table.
5111 3. The default label. */
5113 jump_label = bc_get_bytecode_label ();
5114 bc_emit_bytecode_labelref (jump_label);
5115 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5116 sizeof thiscase->data.case_stmt.num_ranges);
5118 if (thiscase->data.case_stmt.default_label)
5119 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5121 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5123 /* Output the jump table. */
5125 bc_align_bytecode (3 /* PTR_ALIGN */);
5126 bc_emit_bytecode_labeldef (jump_label);
5128 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5129 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5131 opcode = TREE_INT_CST_LOW (c->low);
5132 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5134 opcode = TREE_INT_CST_LOW (c->high);
5135 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5137 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5140 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5141 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5143 bc_emit_bytecode_DI_const (c->low);
5144 bc_emit_bytecode_DI_const (c->high);
5146 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5153 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5155 /* Possibly issue enumeration warnings. */
5157 if (!thiscase->data.case_stmt.default_label
5158 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5159 && TREE_CODE (expr) != INTEGER_CST
5161 check_for_full_enumeration_handling (TREE_TYPE (expr));
5164 #ifdef DEBUG_PRINT_CODE
5165 fputc ('\n', stderr);
5168 POPSTACK (case_stack);
5172 /* Return unique bytecode ID. */
5177 static int bc_uid = 0;
5182 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5185 do_jump_if_equal (op1, op2, label, unsignedp)
5186 rtx op1, op2, label;
5189 if (GET_CODE (op1) == CONST_INT
5190 && GET_CODE (op2) == CONST_INT)
5192 if (INTVAL (op1) == INTVAL (op2))
5197 enum machine_mode mode = GET_MODE (op1);
5198 if (mode == VOIDmode)
5199 mode = GET_MODE (op2);
5200 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5201 emit_jump_insn (gen_beq (label));
5205 /* Not all case values are encountered equally. This function
5206 uses a heuristic to weight case labels, in cases where that
5207 looks like a reasonable thing to do.
5209 Right now, all we try to guess is text, and we establish the
5212 chars above space: 16
5221 If we find any cases in the switch that are not either -1 or in the range
5222 of valid ASCII characters, or are control characters other than those
5223 commonly used with "\", don't treat this switch scanning text.
5225 Return 1 if these nodes are suitable for cost estimation, otherwise
5229 estimate_case_costs (node)
5232 tree min_ascii = build_int_2 (-1, -1);
5233 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5237 /* If we haven't already made the cost table, make it now. Note that the
5238 lower bound of the table is -1, not zero. */
5240 if (cost_table == NULL)
5242 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5243 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5245 for (i = 0; i < 128; i++)
5249 else if (ispunct (i))
5251 else if (iscntrl (i))
5255 cost_table[' '] = 8;
5256 cost_table['\t'] = 4;
5257 cost_table['\0'] = 4;
5258 cost_table['\n'] = 2;
5259 cost_table['\f'] = 1;
5260 cost_table['\v'] = 1;
5261 cost_table['\b'] = 1;
5264 /* See if all the case expressions look like text. It is text if the
5265 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5266 as signed arithmetic since we don't want to ever access cost_table with a
5267 value less than -1. Also check that none of the constants in a range
5268 are strange control characters. */
5270 for (n = node; n; n = n->right)
5272 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5275 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5276 if (cost_table[i] < 0)
5280 /* All interesting values are within the range of interesting
5281 ASCII characters. */
5285 /* Scan an ordered list of case nodes
5286 combining those with consecutive values or ranges.
5288 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5291 group_case_nodes (head)
5294 case_node_ptr node = head;
5298 rtx lb = next_real_insn (label_rtx (node->code_label));
5299 case_node_ptr np = node;
5301 /* Try to group the successors of NODE with NODE. */
5302 while (((np = np->right) != 0)
5303 /* Do they jump to the same place? */
5304 && next_real_insn (label_rtx (np->code_label)) == lb
5305 /* Are their ranges consecutive? */
5306 && tree_int_cst_equal (np->low,
5307 fold (build (PLUS_EXPR,
5308 TREE_TYPE (node->high),
5311 /* An overflow is not consecutive. */
5312 && tree_int_cst_lt (node->high,
5313 fold (build (PLUS_EXPR,
5314 TREE_TYPE (node->high),
5316 integer_one_node))))
5318 node->high = np->high;
5320 /* NP is the first node after NODE which can't be grouped with it.
5321 Delete the nodes in between, and move on to that node. */
5327 /* Take an ordered list of case nodes
5328 and transform them into a near optimal binary tree,
5329 on the assumption that any target code selection value is as
5330 likely as any other.
5332 The transformation is performed by splitting the ordered
5333 list into two equal sections plus a pivot. The parts are
5334 then attached to the pivot as left and right branches. Each
5335 branch is is then transformed recursively. */
5338 balance_case_nodes (head, parent)
5339 case_node_ptr *head;
5340 case_node_ptr parent;
5342 register case_node_ptr np;
5350 register case_node_ptr *npp;
5353 /* Count the number of entries on branch. Also count the ranges. */
5357 if (!tree_int_cst_equal (np->low, np->high))
5361 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5365 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5373 /* Split this list if it is long enough for that to help. */
5378 /* Find the place in the list that bisects the list's total cost,
5379 Here I gets half the total cost. */
5384 /* Skip nodes while their cost does not reach that amount. */
5385 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5386 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5387 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5390 npp = &(*npp)->right;
5395 /* Leave this branch lopsided, but optimize left-hand
5396 side and fill in `parent' fields for right-hand side. */
5398 np->parent = parent;
5399 balance_case_nodes (&np->left, np);
5400 for (; np->right; np = np->right)
5401 np->right->parent = np;
5405 /* If there are just three nodes, split at the middle one. */
5407 npp = &(*npp)->right;
5410 /* Find the place in the list that bisects the list's total cost,
5411 where ranges count as 2.
5412 Here I gets half the total cost. */
5413 i = (i + ranges + 1) / 2;
5416 /* Skip nodes while their cost does not reach that amount. */
5417 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5422 npp = &(*npp)->right;
5427 np->parent = parent;
5430 /* Optimize each of the two split parts. */
5431 balance_case_nodes (&np->left, np);
5432 balance_case_nodes (&np->right, np);
5436 /* Else leave this branch as one level,
5437 but fill in `parent' fields. */
5439 np->parent = parent;
5440 for (; np->right; np = np->right)
5441 np->right->parent = np;
5446 /* Search the parent sections of the case node tree
5447 to see if a test for the lower bound of NODE would be redundant.
5448 INDEX_TYPE is the type of the index expression.
5450 The instructions to generate the case decision tree are
5451 output in the same order as nodes are processed so it is
5452 known that if a parent node checks the range of the current
5453 node minus one that the current node is bounded at its lower
5454 span. Thus the test would be redundant. */
5457 node_has_low_bound (node, index_type)
5462 case_node_ptr pnode;
5464 /* If the lower bound of this node is the lowest value in the index type,
5465 we need not test it. */
5467 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5470 /* If this node has a left branch, the value at the left must be less
5471 than that at this node, so it cannot be bounded at the bottom and
5472 we need not bother testing any further. */
5477 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5478 node->low, integer_one_node));
5480 /* If the subtraction above overflowed, we can't verify anything.
5481 Otherwise, look for a parent that tests our value - 1. */
5483 if (! tree_int_cst_lt (low_minus_one, node->low))
5486 for (pnode = node->parent; pnode; pnode = pnode->parent)
5487 if (tree_int_cst_equal (low_minus_one, pnode->high))
5493 /* Search the parent sections of the case node tree
5494 to see if a test for the upper bound of NODE would be redundant.
5495 INDEX_TYPE is the type of the index expression.
5497 The instructions to generate the case decision tree are
5498 output in the same order as nodes are processed so it is
5499 known that if a parent node checks the range of the current
5500 node plus one that the current node is bounded at its upper
5501 span. Thus the test would be redundant. */
5504 node_has_high_bound (node, index_type)
5509 case_node_ptr pnode;
5511 /* If the upper bound of this node is the highest value in the type
5512 of the index expression, we need not test against it. */
5514 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5517 /* If this node has a right branch, the value at the right must be greater
5518 than that at this node, so it cannot be bounded at the top and
5519 we need not bother testing any further. */
5524 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5525 node->high, integer_one_node));
5527 /* If the addition above overflowed, we can't verify anything.
5528 Otherwise, look for a parent that tests our value + 1. */
5530 if (! tree_int_cst_lt (node->high, high_plus_one))
5533 for (pnode = node->parent; pnode; pnode = pnode->parent)
5534 if (tree_int_cst_equal (high_plus_one, pnode->low))
5540 /* Search the parent sections of the
5541 case node tree to see if both tests for the upper and lower
5542 bounds of NODE would be redundant. */
5545 node_is_bounded (node, index_type)
5549 return (node_has_low_bound (node, index_type)
5550 && node_has_high_bound (node, index_type));
5553 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5556 emit_jump_if_reachable (label)
5559 if (GET_CODE (get_last_insn ()) != BARRIER)
5563 /* Emit step-by-step code to select a case for the value of INDEX.
5564 The thus generated decision tree follows the form of the
5565 case-node binary tree NODE, whose nodes represent test conditions.
5566 INDEX_TYPE is the type of the index of the switch.
5568 Care is taken to prune redundant tests from the decision tree
5569 by detecting any boundary conditions already checked by
5570 emitted rtx. (See node_has_high_bound, node_has_low_bound
5571 and node_is_bounded, above.)
5573 Where the test conditions can be shown to be redundant we emit
5574 an unconditional jump to the target code. As a further
5575 optimization, the subordinates of a tree node are examined to
5576 check for bounded nodes. In this case conditional and/or
5577 unconditional jumps as a result of the boundary check for the
5578 current node are arranged to target the subordinates associated
5579 code for out of bound conditions on the current node node.
5581 We can assume that when control reaches the code generated here,
5582 the index value has already been compared with the parents
5583 of this node, and determined to be on the same side of each parent
5584 as this node is. Thus, if this node tests for the value 51,
5585 and a parent tested for 52, we don't need to consider
5586 the possibility of a value greater than 51. If another parent
5587 tests for the value 50, then this node need not test anything. */
5590 emit_case_nodes (index, node, default_label, index_type)
5596 /* If INDEX has an unsigned type, we must make unsigned branches. */
5597 int unsignedp = TREE_UNSIGNED (index_type);
5598 typedef rtx rtx_function ();
5599 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5600 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5601 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5602 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5603 enum machine_mode mode = GET_MODE (index);
5605 /* See if our parents have already tested everything for us.
5606 If they have, emit an unconditional jump for this node. */
5607 if (node_is_bounded (node, index_type))
5608 emit_jump (label_rtx (node->code_label));
5610 else if (tree_int_cst_equal (node->low, node->high))
5612 /* Node is single valued. First see if the index expression matches
5613 this node and then check our children, if any. */
5615 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5616 label_rtx (node->code_label), unsignedp);
5618 if (node->right != 0 && node->left != 0)
5620 /* This node has children on both sides.
5621 Dispatch to one side or the other
5622 by comparing the index value with this node's value.
5623 If one subtree is bounded, check that one first,
5624 so we can avoid real branches in the tree. */
5626 if (node_is_bounded (node->right, index_type))
5628 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5630 GT, NULL_RTX, mode, unsignedp, 0);
5632 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5633 emit_case_nodes (index, node->left, default_label, index_type);
5636 else if (node_is_bounded (node->left, index_type))
5638 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5640 LT, NULL_RTX, mode, unsignedp, 0);
5641 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5642 emit_case_nodes (index, node->right, default_label, index_type);
5647 /* Neither node is bounded. First distinguish the two sides;
5648 then emit the code for one side at a time. */
5651 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5653 /* See if the value is on the right. */
5654 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5656 GT, NULL_RTX, mode, unsignedp, 0);
5657 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5659 /* Value must be on the left.
5660 Handle the left-hand subtree. */
5661 emit_case_nodes (index, node->left, default_label, index_type);
5662 /* If left-hand subtree does nothing,
5664 emit_jump_if_reachable (default_label);
5666 /* Code branches here for the right-hand subtree. */
5667 expand_label (test_label);
5668 emit_case_nodes (index, node->right, default_label, index_type);
5672 else if (node->right != 0 && node->left == 0)
5674 /* Here we have a right child but no left so we issue conditional
5675 branch to default and process the right child.
5677 Omit the conditional branch to default if we it avoid only one
5678 right child; it costs too much space to save so little time. */
5680 if (node->right->right || node->right->left
5681 || !tree_int_cst_equal (node->right->low, node->right->high))
5683 if (!node_has_low_bound (node, index_type))
5685 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5687 LT, NULL_RTX, mode, unsignedp, 0);
5688 emit_jump_insn ((*gen_blt_pat) (default_label));
5691 emit_case_nodes (index, node->right, default_label, index_type);
5694 /* We cannot process node->right normally
5695 since we haven't ruled out the numbers less than
5696 this node's value. So handle node->right explicitly. */
5697 do_jump_if_equal (index,
5698 expand_expr (node->right->low, NULL_RTX,
5700 label_rtx (node->right->code_label), unsignedp);
5703 else if (node->right == 0 && node->left != 0)
5705 /* Just one subtree, on the left. */
5707 #if 0 /* The following code and comment were formerly part
5708 of the condition here, but they didn't work
5709 and I don't understand what the idea was. -- rms. */
5710 /* If our "most probable entry" is less probable
5711 than the default label, emit a jump to
5712 the default label using condition codes
5713 already lying around. With no right branch,
5714 a branch-greater-than will get us to the default
5717 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5720 if (node->left->left || node->left->right
5721 || !tree_int_cst_equal (node->left->low, node->left->high))
5723 if (!node_has_high_bound (node, index_type))
5725 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5727 GT, NULL_RTX, mode, unsignedp, 0);
5728 emit_jump_insn ((*gen_bgt_pat) (default_label));
5731 emit_case_nodes (index, node->left, default_label, index_type);
5734 /* We cannot process node->left normally
5735 since we haven't ruled out the numbers less than
5736 this node's value. So handle node->left explicitly. */
5737 do_jump_if_equal (index,
5738 expand_expr (node->left->low, NULL_RTX,
5740 label_rtx (node->left->code_label), unsignedp);
5745 /* Node is a range. These cases are very similar to those for a single
5746 value, except that we do not start by testing whether this node
5747 is the one to branch to. */
5749 if (node->right != 0 && node->left != 0)
5751 /* Node has subtrees on both sides.
5752 If the right-hand subtree is bounded,
5753 test for it first, since we can go straight there.
5754 Otherwise, we need to make a branch in the control structure,
5755 then handle the two subtrees. */
5756 tree test_label = 0;
5758 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5760 GT, NULL_RTX, mode, unsignedp, 0);
5762 if (node_is_bounded (node->right, index_type))
5763 /* Right hand node is fully bounded so we can eliminate any
5764 testing and branch directly to the target code. */
5765 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5768 /* Right hand node requires testing.
5769 Branch to a label where we will handle it later. */
5771 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5772 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5775 /* Value belongs to this node or to the left-hand subtree. */
5777 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5778 GE, NULL_RTX, mode, unsignedp, 0);
5779 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5781 /* Handle the left-hand subtree. */
5782 emit_case_nodes (index, node->left, default_label, index_type);
5784 /* If right node had to be handled later, do that now. */
5788 /* If the left-hand subtree fell through,
5789 don't let it fall into the right-hand subtree. */
5790 emit_jump_if_reachable (default_label);
5792 expand_label (test_label);
5793 emit_case_nodes (index, node->right, default_label, index_type);
5797 else if (node->right != 0 && node->left == 0)
5799 /* Deal with values to the left of this node,
5800 if they are possible. */
5801 if (!node_has_low_bound (node, index_type))
5803 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5805 LT, NULL_RTX, mode, unsignedp, 0);
5806 emit_jump_insn ((*gen_blt_pat) (default_label));
5809 /* Value belongs to this node or to the right-hand subtree. */
5811 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5813 LE, NULL_RTX, mode, unsignedp, 0);
5814 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5816 emit_case_nodes (index, node->right, default_label, index_type);
5819 else if (node->right == 0 && node->left != 0)
5821 /* Deal with values to the right of this node,
5822 if they are possible. */
5823 if (!node_has_high_bound (node, index_type))
5825 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5827 GT, NULL_RTX, mode, unsignedp, 0);
5828 emit_jump_insn ((*gen_bgt_pat) (default_label));
5831 /* Value belongs to this node or to the left-hand subtree. */
5833 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5834 GE, NULL_RTX, mode, unsignedp, 0);
5835 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5837 emit_case_nodes (index, node->left, default_label, index_type);
5842 /* Node has no children so we check low and high bounds to remove
5843 redundant tests. Only one of the bounds can exist,
5844 since otherwise this node is bounded--a case tested already. */
5846 if (!node_has_high_bound (node, index_type))
5848 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5850 GT, NULL_RTX, mode, unsignedp, 0);
5851 emit_jump_insn ((*gen_bgt_pat) (default_label));
5854 if (!node_has_low_bound (node, index_type))
5856 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5858 LT, NULL_RTX, mode, unsignedp, 0);
5859 emit_jump_insn ((*gen_blt_pat) (default_label));
5862 emit_jump (label_rtx (node->code_label));
5867 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5868 so that the debugging info will be correct for the unrolled loop. */
5870 /* Indexed by block number, contains a pointer to the N'th block node. */
5872 static tree *block_vector;
5875 find_loop_tree_blocks ()
5877 tree block = DECL_INITIAL (current_function_decl);
5879 block_vector = identify_blocks (block, get_insns ());
5883 unroll_block_trees ()
5885 tree block = DECL_INITIAL (current_function_decl);
5887 reorder_blocks (block_vector, block, get_insns ());