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_ERROR_ISSUED (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_ERROR_ISSUED (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 output_rtx[i] = assign_temp (type, 0, 0, 0);
1481 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1485 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1487 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1491 /* Make vectors for the expression-rtx and constraint strings. */
1493 argvec = rtvec_alloc (ninputs);
1494 constraints = rtvec_alloc (ninputs);
1496 body = gen_rtx (ASM_OPERANDS, VOIDmode,
1497 TREE_STRING_POINTER (string), "", 0, argvec, constraints,
1499 MEM_VOLATILE_P (body) = vol;
1501 /* Eval the inputs and put them into ARGVEC.
1502 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1505 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1510 /* If there's an erroneous arg, emit no insn,
1511 because the ASM_INPUT would get VOIDmode
1512 and that could cause a crash in reload. */
1513 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1515 if (TREE_PURPOSE (tail) == NULL_TREE)
1517 error ("hard register `%s' listed as input operand to `asm'",
1518 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1522 /* Make sure constraint has neither `=' nor `+'. */
1524 for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++)
1525 switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j])
1528 error ("input operand constraint contains `%c'",
1529 TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]);
1532 case '?': case '!': case '*': case '%': case '&':
1533 case 'V': case 'm': case 'o': case '<': case '>':
1534 case 'E': case 'F': case 'G': case 'H': case 'X':
1535 case 's': case 'i': case 'n':
1536 case 'I': case 'J': case 'K': case 'L': case 'M':
1537 case 'N': case 'O': case 'P': case ',':
1538 #ifdef EXTRA_CONSTRAINT
1539 case 'Q': case 'R': case 'S': case 'T': case 'U':
1543 case 'p': case 'g': case 'r':
1544 /* Whether or not a numeric constraint allows a register is
1545 decided by the matching constraint, and so there is no need
1546 to do anything special with them. We must handle them in
1547 the default case, so that we don't unnecessarily force
1548 operands to memory. */
1549 case '0': case '1': case '2': case '3': case '4':
1556 mark_addressable (TREE_VALUE (tail));
1558 XVECEXP (body, 3, i) /* argvec */
1559 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1560 if (CONSTANT_P (XVECEXP (body, 3, i))
1561 && ! general_operand (XVECEXP (body, 3, i),
1562 TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)))))
1565 XVECEXP (body, 3, i)
1566 = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1567 XVECEXP (body, 3, i));
1569 XVECEXP (body, 3, i)
1570 = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1571 XVECEXP (body, 3, i));
1575 && (GET_CODE (XVECEXP (body, 3, i)) == REG
1576 || GET_CODE (XVECEXP (body, 3, i)) == SUBREG
1577 || GET_CODE (XVECEXP (body, 3, i)) == CONCAT))
1579 tree type = TREE_TYPE (TREE_VALUE (tail));
1580 rtx memloc = assign_temp (type, 1, 1, 1);
1582 emit_move_insn (memloc, XVECEXP (body, 3, i));
1583 XVECEXP (body, 3, i) = memloc;
1586 XVECEXP (body, 4, i) /* constraints */
1587 = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1588 TREE_STRING_POINTER (TREE_PURPOSE (tail)));
1592 /* Protect all the operands from the queue,
1593 now that they have all been evaluated. */
1595 for (i = 0; i < ninputs; i++)
1596 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1598 for (i = 0; i < noutputs; i++)
1599 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1601 /* Now, for each output, construct an rtx
1602 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1603 ARGVEC CONSTRAINTS))
1604 If there is more than one, put them inside a PARALLEL. */
1606 if (noutputs == 1 && nclobbers == 0)
1608 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1609 insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body));
1611 else if (noutputs == 0 && nclobbers == 0)
1613 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1614 insn = emit_insn (body);
1620 if (num == 0) num = 1;
1621 body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers));
1623 /* For each output operand, store a SET. */
1625 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1627 XVECEXP (body, 0, i)
1628 = gen_rtx (SET, VOIDmode,
1630 gen_rtx (ASM_OPERANDS, VOIDmode,
1631 TREE_STRING_POINTER (string),
1632 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1633 i, argvec, constraints,
1635 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1638 /* If there are no outputs (but there are some clobbers)
1639 store the bare ASM_OPERANDS into the PARALLEL. */
1642 XVECEXP (body, 0, i++) = obody;
1644 /* Store (clobber REG) for each clobbered register specified. */
1646 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1648 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1649 int j = decode_reg_name (regname);
1653 if (j == -3) /* `cc', which is not a register */
1656 if (j == -4) /* `memory', don't cache memory across asm */
1658 XVECEXP (body, 0, i++)
1659 = gen_rtx (CLOBBER, VOIDmode,
1660 gen_rtx (MEM, BLKmode,
1661 gen_rtx (SCRATCH, VOIDmode, 0)));
1665 /* Ignore unknown register, error already signalled. */
1669 /* Use QImode since that's guaranteed to clobber just one reg. */
1670 XVECEXP (body, 0, i++)
1671 = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j));
1674 insn = emit_insn (body);
1680 /* Generate RTL to evaluate the expression EXP
1681 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1684 expand_expr_stmt (exp)
1687 if (output_bytecode)
1689 int org_stack_depth = stack_depth;
1691 bc_expand_expr (exp);
1693 /* Restore stack depth */
1694 if (stack_depth < org_stack_depth)
1697 bc_emit_instruction (drop);
1699 last_expr_type = TREE_TYPE (exp);
1703 /* If -W, warn about statements with no side effects,
1704 except for an explicit cast to void (e.g. for assert()), and
1705 except inside a ({...}) where they may be useful. */
1706 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1708 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1709 && !(TREE_CODE (exp) == CONVERT_EXPR
1710 && TREE_TYPE (exp) == void_type_node))
1711 warning_with_file_and_line (emit_filename, emit_lineno,
1712 "statement with no effect");
1713 else if (warn_unused)
1714 warn_if_unused_value (exp);
1717 /* If EXP is of function type and we are expanding statements for
1718 value, convert it to pointer-to-function. */
1719 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1720 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1722 last_expr_type = TREE_TYPE (exp);
1723 if (! flag_syntax_only)
1724 last_expr_value = expand_expr (exp,
1725 (expr_stmts_for_value
1726 ? NULL_RTX : const0_rtx),
1729 /* If all we do is reference a volatile value in memory,
1730 copy it to a register to be sure it is actually touched. */
1731 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1732 && TREE_THIS_VOLATILE (exp))
1734 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1736 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1737 copy_to_reg (last_expr_value);
1740 rtx lab = gen_label_rtx ();
1742 /* Compare the value with itself to reference it. */
1743 emit_cmp_insn (last_expr_value, last_expr_value, EQ,
1744 expand_expr (TYPE_SIZE (last_expr_type),
1745 NULL_RTX, VOIDmode, 0),
1747 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT);
1748 emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab));
1753 /* If this expression is part of a ({...}) and is in memory, we may have
1754 to preserve temporaries. */
1755 preserve_temp_slots (last_expr_value);
1757 /* Free any temporaries used to evaluate this expression. Any temporary
1758 used as a result of this expression will already have been preserved
1765 /* Warn if EXP contains any computations whose results are not used.
1766 Return 1 if a warning is printed; 0 otherwise. */
1769 warn_if_unused_value (exp)
1772 if (TREE_USED (exp))
1775 switch (TREE_CODE (exp))
1777 case PREINCREMENT_EXPR:
1778 case POSTINCREMENT_EXPR:
1779 case PREDECREMENT_EXPR:
1780 case POSTDECREMENT_EXPR:
1785 case METHOD_CALL_EXPR:
1787 case WITH_CLEANUP_EXPR:
1789 /* We don't warn about COND_EXPR because it may be a useful
1790 construct if either arm contains a side effect. */
1795 /* For a binding, warn if no side effect within it. */
1796 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1799 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1801 case TRUTH_ORIF_EXPR:
1802 case TRUTH_ANDIF_EXPR:
1803 /* In && or ||, warn if 2nd operand has no side effect. */
1804 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1807 if (TREE_NO_UNUSED_WARNING (exp))
1809 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1811 /* Let people do `(foo (), 0)' without a warning. */
1812 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1814 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1818 case NON_LVALUE_EXPR:
1819 /* Don't warn about values cast to void. */
1820 if (TREE_TYPE (exp) == void_type_node)
1822 /* Don't warn about conversions not explicit in the user's program. */
1823 if (TREE_NO_UNUSED_WARNING (exp))
1825 /* Assignment to a cast usually results in a cast of a modify.
1826 Don't complain about that. There can be an arbitrary number of
1827 casts before the modify, so we must loop until we find the first
1828 non-cast expression and then test to see if that is a modify. */
1830 tree tem = TREE_OPERAND (exp, 0);
1832 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1833 tem = TREE_OPERAND (tem, 0);
1835 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1836 || TREE_CODE (tem) == CALL_EXPR)
1842 /* Don't warn about automatic dereferencing of references, since
1843 the user cannot control it. */
1844 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1845 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1846 /* ... fall through ... */
1849 /* Referencing a volatile value is a side effect, so don't warn. */
1850 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1851 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1852 && TREE_THIS_VOLATILE (exp))
1855 warning_with_file_and_line (emit_filename, emit_lineno,
1856 "value computed is not used");
1861 /* Clear out the memory of the last expression evaluated. */
1869 /* Begin a statement which will return a value.
1870 Return the RTL_EXPR for this statement expr.
1871 The caller must save that value and pass it to expand_end_stmt_expr. */
1874 expand_start_stmt_expr ()
1879 /* When generating bytecode just note down the stack depth */
1880 if (output_bytecode)
1881 return (build_int_2 (stack_depth, 0));
1883 /* Make the RTL_EXPR node temporary, not momentary,
1884 so that rtl_expr_chain doesn't become garbage. */
1885 momentary = suspend_momentary ();
1886 t = make_node (RTL_EXPR);
1887 resume_momentary (momentary);
1888 do_pending_stack_adjust ();
1889 start_sequence_for_rtl_expr (t);
1891 expr_stmts_for_value++;
1895 /* Restore the previous state at the end of a statement that returns a value.
1896 Returns a tree node representing the statement's value and the
1897 insns to compute the value.
1899 The nodes of that expression have been freed by now, so we cannot use them.
1900 But we don't want to do that anyway; the expression has already been
1901 evaluated and now we just want to use the value. So generate a RTL_EXPR
1902 with the proper type and RTL value.
1904 If the last substatement was not an expression,
1905 return something with type `void'. */
1908 expand_end_stmt_expr (t)
1911 if (output_bytecode)
1917 /* At this point, all expressions have been evaluated in order.
1918 However, all expression values have been popped when evaluated,
1919 which means we have to recover the last expression value. This is
1920 the last value removed by means of a `drop' instruction. Instead
1921 of adding code to inhibit dropping the last expression value, it
1922 is here recovered by undoing the `drop'. Since `drop' is
1923 equivalent to `adjustackSI [1]', it can be undone with `adjstackSI
1926 bc_adjust_stack (-1);
1928 if (!last_expr_type)
1929 last_expr_type = void_type_node;
1931 t = make_node (RTL_EXPR);
1932 TREE_TYPE (t) = last_expr_type;
1933 RTL_EXPR_RTL (t) = NULL;
1934 RTL_EXPR_SEQUENCE (t) = NULL;
1936 /* Don't consider deleting this expr or containing exprs at tree level. */
1937 TREE_THIS_VOLATILE (t) = 1;
1945 if (last_expr_type == 0)
1947 last_expr_type = void_type_node;
1948 last_expr_value = const0_rtx;
1950 else if (last_expr_value == 0)
1951 /* There are some cases where this can happen, such as when the
1952 statement is void type. */
1953 last_expr_value = const0_rtx;
1954 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1955 /* Remove any possible QUEUED. */
1956 last_expr_value = protect_from_queue (last_expr_value, 0);
1960 TREE_TYPE (t) = last_expr_type;
1961 RTL_EXPR_RTL (t) = last_expr_value;
1962 RTL_EXPR_SEQUENCE (t) = get_insns ();
1964 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1968 /* Don't consider deleting this expr or containing exprs at tree level. */
1969 TREE_SIDE_EFFECTS (t) = 1;
1970 /* Propagate volatility of the actual RTL expr. */
1971 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1974 expr_stmts_for_value--;
1979 /* Generate RTL for the start of an if-then. COND is the expression
1980 whose truth should be tested.
1982 If EXITFLAG is nonzero, this conditional is visible to
1983 `exit_something'. */
1986 expand_start_cond (cond, exitflag)
1990 struct nesting *thiscond = ALLOC_NESTING ();
1992 /* Make an entry on cond_stack for the cond we are entering. */
1994 thiscond->next = cond_stack;
1995 thiscond->all = nesting_stack;
1996 thiscond->depth = ++nesting_depth;
1997 thiscond->data.cond.next_label = gen_label_rtx ();
1998 /* Before we encounter an `else', we don't need a separate exit label
1999 unless there are supposed to be exit statements
2000 to exit this conditional. */
2001 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2002 thiscond->data.cond.endif_label = thiscond->exit_label;
2003 cond_stack = thiscond;
2004 nesting_stack = thiscond;
2006 if (output_bytecode)
2007 bc_expand_start_cond (cond, exitflag);
2009 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2012 /* Generate RTL between then-clause and the elseif-clause
2013 of an if-then-elseif-.... */
2016 expand_start_elseif (cond)
2019 if (cond_stack->data.cond.endif_label == 0)
2020 cond_stack->data.cond.endif_label = gen_label_rtx ();
2021 emit_jump (cond_stack->data.cond.endif_label);
2022 emit_label (cond_stack->data.cond.next_label);
2023 cond_stack->data.cond.next_label = gen_label_rtx ();
2024 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2027 /* Generate RTL between the then-clause and the else-clause
2028 of an if-then-else. */
2031 expand_start_else ()
2033 if (cond_stack->data.cond.endif_label == 0)
2034 cond_stack->data.cond.endif_label = gen_label_rtx ();
2036 if (output_bytecode)
2038 bc_expand_start_else ();
2042 emit_jump (cond_stack->data.cond.endif_label);
2043 emit_label (cond_stack->data.cond.next_label);
2044 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2047 /* After calling expand_start_else, turn this "else" into an "else if"
2048 by providing another condition. */
2051 expand_elseif (cond)
2054 cond_stack->data.cond.next_label = gen_label_rtx ();
2055 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2058 /* Generate RTL for the end of an if-then.
2059 Pop the record for it off of cond_stack. */
2064 struct nesting *thiscond = cond_stack;
2066 if (output_bytecode)
2067 bc_expand_end_cond ();
2070 do_pending_stack_adjust ();
2071 if (thiscond->data.cond.next_label)
2072 emit_label (thiscond->data.cond.next_label);
2073 if (thiscond->data.cond.endif_label)
2074 emit_label (thiscond->data.cond.endif_label);
2077 POPSTACK (cond_stack);
2082 /* Generate code for the start of an if-then. COND is the expression
2083 whose truth is to be tested; if EXITFLAG is nonzero this conditional
2084 is to be visible to exit_something. It is assumed that the caller
2085 has pushed the previous context on the cond stack. */
2088 bc_expand_start_cond (cond, exitflag)
2092 struct nesting *thiscond = cond_stack;
2094 thiscond->data.case_stmt.nominal_type = cond;
2096 thiscond->exit_label = gen_label_rtx ();
2097 bc_expand_expr (cond);
2098 bc_emit_bytecode (xjumpifnot);
2099 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2101 #ifdef DEBUG_PRINT_CODE
2102 fputc ('\n', stderr);
2106 /* Generate the label for the end of an if with
2110 bc_expand_end_cond ()
2112 struct nesting *thiscond = cond_stack;
2114 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label));
2117 /* Generate code for the start of the else- clause of
2121 bc_expand_start_else ()
2123 struct nesting *thiscond = cond_stack;
2125 thiscond->data.cond.endif_label = thiscond->exit_label;
2126 thiscond->exit_label = gen_label_rtx ();
2127 bc_emit_bytecode (jump);
2128 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label));
2130 #ifdef DEBUG_PRINT_CODE
2131 fputc ('\n', stderr);
2134 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label));
2137 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2138 loop should be exited by `exit_something'. This is a loop for which
2139 `expand_continue' will jump to the top of the loop.
2141 Make an entry on loop_stack to record the labels associated with
2145 expand_start_loop (exit_flag)
2148 register struct nesting *thisloop = ALLOC_NESTING ();
2150 /* Make an entry on loop_stack for the loop we are entering. */
2152 thisloop->next = loop_stack;
2153 thisloop->all = nesting_stack;
2154 thisloop->depth = ++nesting_depth;
2155 thisloop->data.loop.start_label = gen_label_rtx ();
2156 thisloop->data.loop.end_label = gen_label_rtx ();
2157 thisloop->data.loop.alt_end_label = 0;
2158 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2159 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2160 loop_stack = thisloop;
2161 nesting_stack = thisloop;
2163 if (output_bytecode)
2165 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2169 do_pending_stack_adjust ();
2171 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2172 emit_label (thisloop->data.loop.start_label);
2177 /* Like expand_start_loop but for a loop where the continuation point
2178 (for expand_continue_loop) will be specified explicitly. */
2181 expand_start_loop_continue_elsewhere (exit_flag)
2184 struct nesting *thisloop = expand_start_loop (exit_flag);
2185 loop_stack->data.loop.continue_label = gen_label_rtx ();
2189 /* Specify the continuation point for a loop started with
2190 expand_start_loop_continue_elsewhere.
2191 Use this at the point in the code to which a continue statement
2195 expand_loop_continue_here ()
2197 if (output_bytecode)
2199 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label));
2202 do_pending_stack_adjust ();
2203 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2204 emit_label (loop_stack->data.loop.continue_label);
2210 bc_expand_end_loop ()
2212 struct nesting *thisloop = loop_stack;
2214 bc_emit_bytecode (jump);
2215 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label));
2217 #ifdef DEBUG_PRINT_CODE
2218 fputc ('\n', stderr);
2221 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label));
2222 POPSTACK (loop_stack);
2227 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2228 Pop the block off of loop_stack. */
2234 register rtx start_label;
2235 rtx last_test_insn = 0;
2238 if (output_bytecode)
2240 bc_expand_end_loop ();
2244 insn = get_last_insn ();
2245 start_label = loop_stack->data.loop.start_label;
2247 /* Mark the continue-point at the top of the loop if none elsewhere. */
2248 if (start_label == loop_stack->data.loop.continue_label)
2249 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2251 do_pending_stack_adjust ();
2253 /* If optimizing, perhaps reorder the loop. If the loop
2254 starts with a conditional exit, roll that to the end
2255 where it will optimize together with the jump back.
2257 We look for the last conditional branch to the exit that we encounter
2258 before hitting 30 insns or a CALL_INSN. If we see an unconditional
2259 branch to the exit first, use it.
2261 We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes
2262 because moving them is not valid. */
2266 ! (GET_CODE (insn) == JUMP_INSN
2267 && GET_CODE (PATTERN (insn)) == SET
2268 && SET_DEST (PATTERN (insn)) == pc_rtx
2269 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2271 /* Scan insns from the top of the loop looking for a qualified
2272 conditional exit. */
2273 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2274 insn = NEXT_INSN (insn))
2276 if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL)
2279 if (GET_CODE (insn) == NOTE
2280 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2281 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2284 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2287 if (last_test_insn && num_insns > 30)
2290 if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET
2291 && SET_DEST (PATTERN (insn)) == pc_rtx
2292 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE
2293 && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF
2294 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2295 == loop_stack->data.loop.end_label)
2296 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0)
2297 == loop_stack->data.loop.alt_end_label)))
2298 || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF
2299 && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2300 == loop_stack->data.loop.end_label)
2301 || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0)
2302 == loop_stack->data.loop.alt_end_label)))))
2303 last_test_insn = insn;
2305 if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN
2306 && GET_CODE (PATTERN (insn)) == SET
2307 && SET_DEST (PATTERN (insn)) == pc_rtx
2308 && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF
2309 && ((XEXP (SET_SRC (PATTERN (insn)), 0)
2310 == loop_stack->data.loop.end_label)
2311 || (XEXP (SET_SRC (PATTERN (insn)), 0)
2312 == loop_stack->data.loop.alt_end_label)))
2313 /* Include BARRIER. */
2314 last_test_insn = NEXT_INSN (insn);
2317 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2319 /* We found one. Move everything from there up
2320 to the end of the loop, and add a jump into the loop
2321 to jump to there. */
2322 register rtx newstart_label = gen_label_rtx ();
2323 register rtx start_move = start_label;
2325 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2326 then we want to move this note also. */
2327 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2328 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2329 == NOTE_INSN_LOOP_CONT))
2330 start_move = PREV_INSN (start_move);
2332 emit_label_after (newstart_label, PREV_INSN (start_move));
2333 reorder_insns (start_move, last_test_insn, get_last_insn ());
2334 emit_jump_insn_after (gen_jump (start_label),
2335 PREV_INSN (newstart_label));
2336 emit_barrier_after (PREV_INSN (newstart_label));
2337 start_label = newstart_label;
2341 emit_jump (start_label);
2342 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2343 emit_label (loop_stack->data.loop.end_label);
2345 POPSTACK (loop_stack);
2350 /* Generate a jump to the current loop's continue-point.
2351 This is usually the top of the loop, but may be specified
2352 explicitly elsewhere. If not currently inside a loop,
2353 return 0 and do nothing; caller will print an error message. */
2356 expand_continue_loop (whichloop)
2357 struct nesting *whichloop;
2361 whichloop = loop_stack;
2364 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2369 /* Generate a jump to exit the current loop. If not currently inside a loop,
2370 return 0 and do nothing; caller will print an error message. */
2373 expand_exit_loop (whichloop)
2374 struct nesting *whichloop;
2378 whichloop = loop_stack;
2381 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2385 /* Generate a conditional jump to exit the current loop if COND
2386 evaluates to zero. If not currently inside a loop,
2387 return 0 and do nothing; caller will print an error message. */
2390 expand_exit_loop_if_false (whichloop, cond)
2391 struct nesting *whichloop;
2396 whichloop = loop_stack;
2399 if (output_bytecode)
2401 bc_expand_expr (cond);
2402 bc_expand_goto_internal (xjumpifnot,
2403 BYTECODE_BC_LABEL (whichloop->exit_label),
2408 /* In order to handle fixups, we actually create a conditional jump
2409 around a unconditional branch to exit the loop. If fixups are
2410 necessary, they go before the unconditional branch. */
2412 rtx label = gen_label_rtx ();
2415 do_jump (cond, NULL_RTX, label);
2416 last_insn = get_last_insn ();
2417 if (GET_CODE (last_insn) == CODE_LABEL)
2418 whichloop->data.loop.alt_end_label = last_insn;
2419 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2427 /* Return non-zero if we should preserve sub-expressions as separate
2428 pseudos. We never do so if we aren't optimizing. We always do so
2429 if -fexpensive-optimizations.
2431 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2432 the loop may still be a small one. */
2435 preserve_subexpressions_p ()
2439 if (flag_expensive_optimizations)
2442 if (optimize == 0 || loop_stack == 0)
2445 insn = get_last_insn_anywhere ();
2448 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2449 < n_non_fixed_regs * 3));
2453 /* Generate a jump to exit the current loop, conditional, binding contour
2454 or case statement. Not all such constructs are visible to this function,
2455 only those started with EXIT_FLAG nonzero. Individual languages use
2456 the EXIT_FLAG parameter to control which kinds of constructs you can
2459 If not currently inside anything that can be exited,
2460 return 0 and do nothing; caller will print an error message. */
2463 expand_exit_something ()
2467 for (n = nesting_stack; n; n = n->all)
2468 if (n->exit_label != 0)
2470 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2477 /* Generate RTL to return from the current function, with no value.
2478 (That is, we do not do anything about returning any value.) */
2481 expand_null_return ()
2483 struct nesting *block = block_stack;
2486 if (output_bytecode)
2488 bc_emit_instruction (ret);
2492 /* Does any pending block have cleanups? */
2494 while (block && block->data.block.cleanups == 0)
2495 block = block->next;
2497 /* If yes, use a goto to return, since that runs cleanups. */
2499 expand_null_return_1 (last_insn, block != 0);
2502 /* Generate RTL to return from the current function, with value VAL. */
2505 expand_value_return (val)
2508 struct nesting *block = block_stack;
2509 rtx last_insn = get_last_insn ();
2510 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2512 /* Copy the value to the return location
2513 unless it's already there. */
2515 if (return_reg != val)
2517 #ifdef PROMOTE_FUNCTION_RETURN
2518 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2519 int unsignedp = TREE_UNSIGNED (type);
2520 enum machine_mode mode
2521 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2524 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2525 convert_move (return_reg, val, unsignedp);
2528 emit_move_insn (return_reg, val);
2530 if (GET_CODE (return_reg) == REG
2531 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2532 emit_insn (gen_rtx (USE, VOIDmode, return_reg));
2534 /* Does any pending block have cleanups? */
2536 while (block && block->data.block.cleanups == 0)
2537 block = block->next;
2539 /* If yes, use a goto to return, since that runs cleanups.
2540 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2542 expand_null_return_1 (last_insn, block != 0);
2545 /* Output a return with no value. If LAST_INSN is nonzero,
2546 pretend that the return takes place after LAST_INSN.
2547 If USE_GOTO is nonzero then don't use a return instruction;
2548 go to the return label instead. This causes any cleanups
2549 of pending blocks to be executed normally. */
2552 expand_null_return_1 (last_insn, use_goto)
2556 rtx end_label = cleanup_label ? cleanup_label : return_label;
2558 clear_pending_stack_adjust ();
2559 do_pending_stack_adjust ();
2562 /* PCC-struct return always uses an epilogue. */
2563 if (current_function_returns_pcc_struct || use_goto)
2566 end_label = return_label = gen_label_rtx ();
2567 expand_goto_internal (NULL_TREE, end_label, last_insn);
2571 /* Otherwise output a simple return-insn if one is available,
2572 unless it won't do the job. */
2574 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2576 emit_jump_insn (gen_return ());
2582 /* Otherwise jump to the epilogue. */
2583 expand_goto_internal (NULL_TREE, end_label, last_insn);
2586 /* Generate RTL to evaluate the expression RETVAL and return it
2587 from the current function. */
2590 expand_return (retval)
2593 /* If there are any cleanups to be performed, then they will
2594 be inserted following LAST_INSN. It is desirable
2595 that the last_insn, for such purposes, should be the
2596 last insn before computing the return value. Otherwise, cleanups
2597 which call functions can clobber the return value. */
2598 /* ??? rms: I think that is erroneous, because in C++ it would
2599 run destructors on variables that might be used in the subsequent
2600 computation of the return value. */
2602 register rtx val = 0;
2606 struct nesting *block;
2608 /* Bytecode returns are quite simple, just leave the result on the
2609 arithmetic stack. */
2610 if (output_bytecode)
2612 bc_expand_expr (retval);
2613 bc_emit_instruction (ret);
2617 /* If function wants no value, give it none. */
2618 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2620 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2622 expand_null_return ();
2626 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2627 /* This is not sufficient. We also need to watch for cleanups of the
2628 expression we are about to expand. Unfortunately, we cannot know
2629 if it has cleanups until we expand it, and we want to change how we
2630 expand it depending upon if we need cleanups. We can't win. */
2632 cleanups = any_pending_cleanups (1);
2637 if (TREE_CODE (retval) == RESULT_DECL)
2638 retval_rhs = retval;
2639 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2640 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2641 retval_rhs = TREE_OPERAND (retval, 1);
2642 else if (TREE_TYPE (retval) == void_type_node)
2643 /* Recognize tail-recursive call to void function. */
2644 retval_rhs = retval;
2646 retval_rhs = NULL_TREE;
2648 /* Only use `last_insn' if there are cleanups which must be run. */
2649 if (cleanups || cleanup_label != 0)
2650 last_insn = get_last_insn ();
2652 /* Distribute return down conditional expr if either of the sides
2653 may involve tail recursion (see test below). This enhances the number
2654 of tail recursions we see. Don't do this always since it can produce
2655 sub-optimal code in some cases and we distribute assignments into
2656 conditional expressions when it would help. */
2658 if (optimize && retval_rhs != 0
2659 && frame_offset == 0
2660 && TREE_CODE (retval_rhs) == COND_EXPR
2661 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2662 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2664 rtx label = gen_label_rtx ();
2667 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2668 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2669 DECL_RESULT (current_function_decl),
2670 TREE_OPERAND (retval_rhs, 1));
2671 TREE_SIDE_EFFECTS (expr) = 1;
2672 expand_return (expr);
2675 expr = build (MODIFY_EXPR, TREE_TYPE (current_function_decl),
2676 DECL_RESULT (current_function_decl),
2677 TREE_OPERAND (retval_rhs, 2));
2678 TREE_SIDE_EFFECTS (expr) = 1;
2679 expand_return (expr);
2683 /* For tail-recursive call to current function,
2684 just jump back to the beginning.
2685 It's unsafe if any auto variable in this function
2686 has its address taken; for simplicity,
2687 require stack frame to be empty. */
2688 if (optimize && retval_rhs != 0
2689 && frame_offset == 0
2690 && TREE_CODE (retval_rhs) == CALL_EXPR
2691 && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR
2692 && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl
2693 /* Finish checking validity, and if valid emit code
2694 to set the argument variables for the new call. */
2695 && tail_recursion_args (TREE_OPERAND (retval_rhs, 1),
2696 DECL_ARGUMENTS (current_function_decl)))
2698 if (tail_recursion_label == 0)
2700 tail_recursion_label = gen_label_rtx ();
2701 emit_label_after (tail_recursion_label,
2702 tail_recursion_reentry);
2705 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2710 /* This optimization is safe if there are local cleanups
2711 because expand_null_return takes care of them.
2712 ??? I think it should also be safe when there is a cleanup label,
2713 because expand_null_return takes care of them, too.
2714 Any reason why not? */
2715 if (HAVE_return && cleanup_label == 0
2716 && ! current_function_returns_pcc_struct
2717 && BRANCH_COST <= 1)
2719 /* If this is return x == y; then generate
2720 if (x == y) return 1; else return 0;
2721 if we can do it with explicit return insns and
2722 branches are cheap. */
2724 switch (TREE_CODE (retval_rhs))
2732 case TRUTH_ANDIF_EXPR:
2733 case TRUTH_ORIF_EXPR:
2734 case TRUTH_AND_EXPR:
2736 case TRUTH_NOT_EXPR:
2737 case TRUTH_XOR_EXPR:
2738 op0 = gen_label_rtx ();
2739 jumpifnot (retval_rhs, op0);
2740 expand_value_return (const1_rtx);
2742 expand_value_return (const0_rtx);
2746 #endif /* HAVE_return */
2748 /* If the result is an aggregate that is being returned in one (or more)
2749 registers, load the registers here. The compiler currently can't handle
2750 copying a BLKmode value into registers. We could put this code in a
2751 more general area (for use by everyone instead of just function
2752 call/return), but until this feature is generally usable it is kept here
2753 (and in expand_call). The value must go into a pseudo in case there
2754 are cleanups that will clobber the real return register. */
2757 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2758 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2760 int i, bitpos, xbitpos;
2761 int big_endian_correction = 0;
2762 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2763 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2764 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD);
2765 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2766 rtx result_reg, src, dst;
2767 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2768 enum machine_mode tmpmode, result_reg_mode;
2770 /* Structures whose size is not a multiple of a word are aligned
2771 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2772 machine, this means we must skip the empty high order bytes when
2773 calculating the bit offset. */
2774 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2775 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2778 /* Copy the structure BITSIZE bits at a time. */
2779 for (bitpos = 0, xbitpos = big_endian_correction;
2780 bitpos < bytes * BITS_PER_UNIT;
2781 bitpos += bitsize, xbitpos += bitsize)
2783 /* We need a new destination pseudo each time xbitpos is
2784 on a word boundary and when xbitpos == big_endian_correction
2785 (the first time through). */
2786 if (xbitpos % BITS_PER_WORD == 0
2787 || xbitpos == big_endian_correction)
2789 /* Generate an appropriate register. */
2790 dst = gen_reg_rtx (word_mode);
2791 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2793 /* Clobber the destination before we move anything into it. */
2794 emit_insn (gen_rtx (CLOBBER, VOIDmode, dst));
2797 /* We need a new source operand each time bitpos is on a word
2799 if (bitpos % BITS_PER_WORD == 0)
2800 src = operand_subword_force (result_val,
2801 bitpos / BITS_PER_WORD,
2804 /* Use bitpos for the source extraction (left justified) and
2805 xbitpos for the destination store (right justified). */
2806 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2807 extract_bit_field (src, bitsize,
2808 bitpos % BITS_PER_WORD, 1,
2809 NULL_RTX, word_mode,
2811 bitsize / BITS_PER_UNIT,
2813 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2816 /* Find the smallest integer mode large enough to hold the
2817 entire structure and use that mode instead of BLKmode
2818 on the USE insn for the return register. */
2819 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2820 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2821 tmpmode != MAX_MACHINE_MODE;
2822 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2824 /* Have we found a large enough mode? */
2825 if (GET_MODE_SIZE (tmpmode) >= bytes)
2829 /* No suitable mode found. */
2830 if (tmpmode == MAX_MACHINE_MODE)
2833 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2835 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2836 result_reg_mode = word_mode;
2838 result_reg_mode = tmpmode;
2839 result_reg = gen_reg_rtx (result_reg_mode);
2841 /* Now that the value is in pseudos, copy it to the result reg(s). */
2844 for (i = 0; i < n_regs; i++)
2845 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2848 if (tmpmode != result_reg_mode)
2849 result_reg = gen_lowpart (tmpmode, result_reg);
2851 expand_value_return (result_reg);
2855 && TREE_TYPE (retval_rhs) != void_type_node
2856 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2858 /* Calculate the return value into a pseudo reg. */
2859 val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2861 /* All temporaries have now been used. */
2863 /* Return the calculated value, doing cleanups first. */
2864 expand_value_return (val);
2868 /* No cleanups or no hard reg used;
2869 calculate value into hard return reg. */
2870 expand_expr (retval, const0_rtx, VOIDmode, 0);
2873 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2877 /* Return 1 if the end of the generated RTX is not a barrier.
2878 This means code already compiled can drop through. */
2881 drop_through_at_end_p ()
2883 rtx insn = get_last_insn ();
2884 while (insn && GET_CODE (insn) == NOTE)
2885 insn = PREV_INSN (insn);
2886 return insn && GET_CODE (insn) != BARRIER;
2889 /* Emit code to alter this function's formal parms for a tail-recursive call.
2890 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2891 FORMALS is the chain of decls of formals.
2892 Return 1 if this can be done;
2893 otherwise return 0 and do not emit any code. */
2896 tail_recursion_args (actuals, formals)
2897 tree actuals, formals;
2899 register tree a = actuals, f = formals;
2901 register rtx *argvec;
2903 /* Check that number and types of actuals are compatible
2904 with the formals. This is not always true in valid C code.
2905 Also check that no formal needs to be addressable
2906 and that all formals are scalars. */
2908 /* Also count the args. */
2910 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2912 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
2913 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
2915 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2918 if (a != 0 || f != 0)
2921 /* Compute all the actuals. */
2923 argvec = (rtx *) alloca (i * sizeof (rtx));
2925 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2926 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2928 /* Find which actual values refer to current values of previous formals.
2929 Copy each of them now, before any formal is changed. */
2931 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2935 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2936 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2937 { copy = 1; break; }
2939 argvec[i] = copy_to_reg (argvec[i]);
2942 /* Store the values of the actuals into the formals. */
2944 for (f = formals, a = actuals, i = 0; f;
2945 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2947 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2948 emit_move_insn (DECL_RTL (f), argvec[i]);
2950 convert_move (DECL_RTL (f), argvec[i],
2951 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2958 /* Generate the RTL code for entering a binding contour.
2959 The variables are declared one by one, by calls to `expand_decl'.
2961 EXIT_FLAG is nonzero if this construct should be visible to
2962 `exit_something'. */
2965 expand_start_bindings (exit_flag)
2968 struct nesting *thisblock = ALLOC_NESTING ();
2969 rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2971 /* Make an entry on block_stack for the block we are entering. */
2973 thisblock->next = block_stack;
2974 thisblock->all = nesting_stack;
2975 thisblock->depth = ++nesting_depth;
2976 thisblock->data.block.stack_level = 0;
2977 thisblock->data.block.cleanups = 0;
2978 thisblock->data.block.function_call_count = 0;
2982 if (block_stack->data.block.cleanups == NULL_TREE
2983 && (block_stack->data.block.outer_cleanups == NULL_TREE
2984 || block_stack->data.block.outer_cleanups == empty_cleanup_list))
2985 thisblock->data.block.outer_cleanups = empty_cleanup_list;
2987 thisblock->data.block.outer_cleanups
2988 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2989 block_stack->data.block.outer_cleanups);
2992 thisblock->data.block.outer_cleanups = 0;
2996 && !(block_stack->data.block.cleanups == NULL_TREE
2997 && block_stack->data.block.outer_cleanups == NULL_TREE))
2998 thisblock->data.block.outer_cleanups
2999 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3000 block_stack->data.block.outer_cleanups);
3002 thisblock->data.block.outer_cleanups = 0;
3004 thisblock->data.block.label_chain = 0;
3005 thisblock->data.block.innermost_stack_block = stack_block_stack;
3006 thisblock->data.block.first_insn = note;
3007 thisblock->data.block.block_start_count = ++block_start_count;
3008 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3009 block_stack = thisblock;
3010 nesting_stack = thisblock;
3012 if (!output_bytecode)
3014 /* Make a new level for allocating stack slots. */
3019 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3020 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3024 remember_end_note (block)
3025 register tree block;
3027 BLOCK_END_NOTE (block) = last_block_end_note;
3028 last_block_end_note = NULL_RTX;
3031 /* Generate RTL code to terminate a binding contour.
3032 VARS is the chain of VAR_DECL nodes
3033 for the variables bound in this contour.
3034 MARK_ENDS is nonzero if we should put a note at the beginning
3035 and end of this binding contour.
3037 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3038 (That is true automatically if the contour has a saved stack level.) */
3041 expand_end_bindings (vars, mark_ends, dont_jump_in)
3046 register struct nesting *thisblock = block_stack;
3049 if (output_bytecode)
3051 bc_expand_end_bindings (vars, mark_ends, dont_jump_in);
3056 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3057 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
3058 && ! DECL_IN_SYSTEM_HEADER (decl))
3059 warning_with_decl (decl, "unused variable `%s'");
3061 if (thisblock->exit_label)
3063 do_pending_stack_adjust ();
3064 emit_label (thisblock->exit_label);
3067 /* If necessary, make a handler for nonlocal gotos taking
3068 place in the function calls in this block. */
3069 if (function_call_count != thisblock->data.block.function_call_count
3071 /* Make handler for outermost block
3072 if there were any nonlocal gotos to this function. */
3073 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3074 /* Make handler for inner block if it has something
3075 special to do when you jump out of it. */
3076 : (thisblock->data.block.cleanups != 0
3077 || thisblock->data.block.stack_level != 0)))
3080 rtx afterward = gen_label_rtx ();
3081 rtx handler_label = gen_label_rtx ();
3082 rtx save_receiver = gen_reg_rtx (Pmode);
3085 /* Don't let jump_optimize delete the handler. */
3086 LABEL_PRESERVE_P (handler_label) = 1;
3088 /* Record the handler address in the stack slot for that purpose,
3089 during this block, saving and restoring the outer value. */
3090 if (thisblock->next != 0)
3092 emit_move_insn (nonlocal_goto_handler_slot, save_receiver);
3095 emit_move_insn (save_receiver, nonlocal_goto_handler_slot);
3096 insns = get_insns ();
3098 emit_insns_before (insns, thisblock->data.block.first_insn);
3102 emit_move_insn (nonlocal_goto_handler_slot,
3103 gen_rtx (LABEL_REF, Pmode, handler_label));
3104 insns = get_insns ();
3106 emit_insns_before (insns, thisblock->data.block.first_insn);
3108 /* Jump around the handler; it runs only when specially invoked. */
3109 emit_jump (afterward);
3110 emit_label (handler_label);
3112 #ifdef HAVE_nonlocal_goto
3113 if (! HAVE_nonlocal_goto)
3115 /* First adjust our frame pointer to its actual value. It was
3116 previously set to the start of the virtual area corresponding to
3117 the stacked variables when we branched here and now needs to be
3118 adjusted to the actual hardware fp value.
3120 Assignments are to virtual registers are converted by
3121 instantiate_virtual_regs into the corresponding assignment
3122 to the underlying register (fp in this case) that makes
3123 the original assignment true.
3124 So the following insn will actually be
3125 decrementing fp by STARTING_FRAME_OFFSET. */
3126 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3128 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3129 if (fixed_regs[ARG_POINTER_REGNUM])
3131 #ifdef ELIMINABLE_REGS
3132 /* If the argument pointer can be eliminated in favor of the
3133 frame pointer, we don't need to restore it. We assume here
3134 that if such an elimination is present, it can always be used.
3135 This is the case on all known machines; if we don't make this
3136 assumption, we do unnecessary saving on many machines. */
3137 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3140 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3141 if (elim_regs[i].from == ARG_POINTER_REGNUM
3142 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3145 if (i == sizeof elim_regs / sizeof elim_regs [0])
3148 /* Now restore our arg pointer from the address at which it
3149 was saved in our stack frame.
3150 If there hasn't be space allocated for it yet, make
3152 if (arg_pointer_save_area == 0)
3153 arg_pointer_save_area
3154 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3155 emit_move_insn (virtual_incoming_args_rtx,
3156 /* We need a pseudo here, or else
3157 instantiate_virtual_regs_1 complains. */
3158 copy_to_reg (arg_pointer_save_area));
3163 /* The handler expects the desired label address in the static chain
3164 register. It tests the address and does an appropriate jump
3165 to whatever label is desired. */
3166 for (link = nonlocal_labels; link; link = TREE_CHAIN (link))
3167 /* Skip any labels we shouldn't be able to jump to from here. */
3168 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3170 rtx not_this = gen_label_rtx ();
3171 rtx this = gen_label_rtx ();
3172 do_jump_if_equal (static_chain_rtx,
3173 gen_rtx (LABEL_REF, Pmode, DECL_RTL (TREE_VALUE (link))),
3175 emit_jump (not_this);
3177 expand_goto (TREE_VALUE (link));
3178 emit_label (not_this);
3180 /* If label is not recognized, abort. */
3181 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "abort"), 0,
3184 emit_label (afterward);
3187 /* Don't allow jumping into a block that has cleanups or a stack level. */
3189 || thisblock->data.block.stack_level != 0
3190 || thisblock->data.block.cleanups != 0)
3192 struct label_chain *chain;
3194 /* Any labels in this block are no longer valid to go to.
3195 Mark them to cause an error message. */
3196 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3198 DECL_TOO_LATE (chain->label) = 1;
3199 /* If any goto without a fixup came to this label,
3200 that must be an error, because gotos without fixups
3201 come from outside all saved stack-levels and all cleanups. */
3202 if (TREE_ADDRESSABLE (chain->label))
3203 error_with_decl (chain->label,
3204 "label `%s' used before containing binding contour");
3208 /* Restore stack level in effect before the block
3209 (only if variable-size objects allocated). */
3210 /* Perform any cleanups associated with the block. */
3212 if (thisblock->data.block.stack_level != 0
3213 || thisblock->data.block.cleanups != 0)
3215 /* Only clean up here if this point can actually be reached. */
3216 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3218 /* Don't let cleanups affect ({...}) constructs. */
3219 int old_expr_stmts_for_value = expr_stmts_for_value;
3220 rtx old_last_expr_value = last_expr_value;
3221 tree old_last_expr_type = last_expr_type;
3222 expr_stmts_for_value = 0;
3224 /* Do the cleanups. */
3225 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3227 do_pending_stack_adjust ();
3229 expr_stmts_for_value = old_expr_stmts_for_value;
3230 last_expr_value = old_last_expr_value;
3231 last_expr_type = old_last_expr_type;
3233 /* Restore the stack level. */
3235 if (reachable && thisblock->data.block.stack_level != 0)
3237 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3238 thisblock->data.block.stack_level, NULL_RTX);
3239 if (nonlocal_goto_handler_slot != 0)
3240 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3244 /* Any gotos out of this block must also do these things.
3245 Also report any gotos with fixups that came to labels in this
3247 fixup_gotos (thisblock,
3248 thisblock->data.block.stack_level,
3249 thisblock->data.block.cleanups,
3250 thisblock->data.block.first_insn,
3254 /* Mark the beginning and end of the scope if requested.
3255 We do this now, after running cleanups on the variables
3256 just going out of scope, so they are in scope for their cleanups. */
3259 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3261 /* Get rid of the beginning-mark if we don't make an end-mark. */
3262 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3264 /* If doing stupid register allocation, make sure lives of all
3265 register variables declared here extend thru end of scope. */
3268 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3270 rtx rtl = DECL_RTL (decl);
3271 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3275 /* Restore block_stack level for containing block. */
3277 stack_block_stack = thisblock->data.block.innermost_stack_block;
3278 POPSTACK (block_stack);
3280 /* Pop the stack slot nesting and free any slots at this level. */
3285 /* End a binding contour.
3286 VARS is the chain of VAR_DECL nodes for the variables bound
3287 in this contour. MARK_ENDS is nonzer if we should put a note
3288 at the beginning and end of this binding contour.
3289 DONT_JUMP_IN is nonzero if it is not valid to jump into this
3293 bc_expand_end_bindings (vars, mark_ends, dont_jump_in)
3298 struct nesting *thisbind = nesting_stack;
3302 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3303 if (! TREE_USED (TREE_VALUE (decl)) && TREE_CODE (TREE_VALUE (decl)) == VAR_DECL)
3304 warning_with_decl (decl, "unused variable `%s'");
3306 if (thisbind->exit_label)
3307 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisbind->exit_label));
3309 /* Pop block/bindings off stack */
3310 POPSTACK (block_stack);
3313 /* Generate RTL for the automatic variable declaration DECL.
3314 (Other kinds of declarations are simply ignored if seen here.) */
3320 struct nesting *thisblock = block_stack;
3323 if (output_bytecode)
3325 bc_expand_decl (decl, 0);
3329 type = TREE_TYPE (decl);
3331 /* Only automatic variables need any expansion done.
3332 Static and external variables, and external functions,
3333 will be handled by `assemble_variable' (called from finish_decl).
3334 TYPE_DECL and CONST_DECL require nothing.
3335 PARM_DECLs are handled in `assign_parms'. */
3337 if (TREE_CODE (decl) != VAR_DECL)
3339 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3342 /* Create the RTL representation for the variable. */
3344 if (type == error_mark_node)
3345 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, const0_rtx);
3346 else if (DECL_SIZE (decl) == 0)
3347 /* Variable with incomplete type. */
3349 if (DECL_INITIAL (decl) == 0)
3350 /* Error message was already done; now avoid a crash. */
3351 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3353 /* An initializer is going to decide the size of this array.
3354 Until we know the size, represent its address with a reg. */
3355 DECL_RTL (decl) = gen_rtx (MEM, BLKmode, gen_reg_rtx (Pmode));
3356 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (type);
3358 else if (DECL_MODE (decl) != BLKmode
3359 /* If -ffloat-store, don't put explicit float vars
3361 && !(flag_float_store
3362 && TREE_CODE (type) == REAL_TYPE)
3363 && ! TREE_THIS_VOLATILE (decl)
3364 && ! TREE_ADDRESSABLE (decl)
3365 && (DECL_REGISTER (decl) || ! obey_regdecls))
3367 /* Automatic variable that can go in a register. */
3368 int unsignedp = TREE_UNSIGNED (type);
3369 enum machine_mode reg_mode
3370 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3372 if (TREE_CODE (type) == COMPLEX_TYPE)
3374 rtx realpart, imagpart;
3375 enum machine_mode partmode = TYPE_MODE (TREE_TYPE (type));
3377 /* For a complex type variable, make a CONCAT of two pseudos
3378 so that the real and imaginary parts
3379 can be allocated separately. */
3380 realpart = gen_reg_rtx (partmode);
3381 REG_USERVAR_P (realpart) = 1;
3382 imagpart = gen_reg_rtx (partmode);
3383 REG_USERVAR_P (imagpart) = 1;
3384 DECL_RTL (decl) = gen_rtx (CONCAT, reg_mode, realpart, imagpart);
3388 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3389 if (TREE_CODE (type) == POINTER_TYPE)
3390 mark_reg_pointer (DECL_RTL (decl),
3391 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3393 REG_USERVAR_P (DECL_RTL (decl)) = 1;
3396 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST)
3398 /* Variable of fixed size that goes on the stack. */
3402 /* If we previously made RTL for this decl, it must be an array
3403 whose size was determined by the initializer.
3404 The old address was a register; set that register now
3405 to the proper address. */
3406 if (DECL_RTL (decl) != 0)
3408 if (GET_CODE (DECL_RTL (decl)) != MEM
3409 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3411 oldaddr = XEXP (DECL_RTL (decl), 0);
3415 = assign_stack_temp (DECL_MODE (decl),
3416 ((TREE_INT_CST_LOW (DECL_SIZE (decl))
3417 + BITS_PER_UNIT - 1)
3420 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3422 /* Set alignment we actually gave this decl. */
3423 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3424 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3428 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3429 if (addr != oldaddr)
3430 emit_move_insn (oldaddr, addr);
3433 /* If this is a memory ref that contains aggregate components,
3434 mark it as such for cse and loop optimize. */
3435 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3437 /* If this is in memory because of -ffloat-store,
3438 set the volatile bit, to prevent optimizations from
3439 undoing the effects. */
3440 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3441 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3445 /* Dynamic-size object: must push space on the stack. */
3449 /* Record the stack pointer on entry to block, if have
3450 not already done so. */
3451 if (thisblock->data.block.stack_level == 0)
3453 do_pending_stack_adjust ();
3454 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3455 &thisblock->data.block.stack_level,
3456 thisblock->data.block.first_insn);
3457 stack_block_stack = thisblock;
3460 /* Compute the variable's size, in bytes. */
3461 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3463 size_int (BITS_PER_UNIT)),
3464 NULL_RTX, VOIDmode, 0);
3467 /* Allocate space on the stack for the variable. */
3468 address = allocate_dynamic_stack_space (size, NULL_RTX,
3471 /* Reference the variable indirect through that rtx. */
3472 DECL_RTL (decl) = gen_rtx (MEM, DECL_MODE (decl), address);
3474 /* If this is a memory ref that contains aggregate components,
3475 mark it as such for cse and loop optimize. */
3476 MEM_IN_STRUCT_P (DECL_RTL (decl)) = AGGREGATE_TYPE_P (TREE_TYPE (decl));
3478 /* Indicate the alignment we actually gave this variable. */
3479 #ifdef STACK_BOUNDARY
3480 DECL_ALIGN (decl) = STACK_BOUNDARY;
3482 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3486 if (TREE_THIS_VOLATILE (decl))
3487 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3488 #if 0 /* A variable is not necessarily unchanging
3489 just because it is const. RTX_UNCHANGING_P
3490 means no change in the function,
3491 not merely no change in the variable's scope.
3492 It is correct to set RTX_UNCHANGING_P if the variable's scope
3493 is the whole function. There's no convenient way to test that. */
3494 if (TREE_READONLY (decl))
3495 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3498 /* If doing stupid register allocation, make sure life of any
3499 register variable starts here, at the start of its scope. */
3502 use_variable (DECL_RTL (decl));
3506 /* Generate code for the automatic variable declaration DECL. For
3507 most variables this just means we give it a stack offset. The
3508 compiler sometimes emits cleanups without variables and we will
3509 have to deal with those too. */
3512 bc_expand_decl (decl, cleanup)
3520 /* A cleanup with no variable. */
3527 /* Only auto variables need any work. */
3528 if (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3531 type = TREE_TYPE (decl);
3533 if (type == error_mark_node)
3534 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3536 else if (DECL_SIZE (decl) == 0)
3538 /* Variable with incomplete type. The stack offset herein will be
3539 fixed later in expand_decl_init (). */
3540 DECL_RTL (decl) = bc_gen_rtx ((char *) 0, 0, (struct bc_label *) 0);
3542 else if (TREE_CONSTANT (DECL_SIZE (decl)))
3544 DECL_RTL (decl) = bc_allocate_local (TREE_INT_CST_LOW (DECL_SIZE (decl)) / BITS_PER_UNIT,
3548 DECL_RTL (decl) = bc_allocate_variable_array (DECL_SIZE (decl));
3551 /* Emit code to perform the initialization of a declaration DECL. */
3554 expand_decl_init (decl)
3557 int was_used = TREE_USED (decl);
3559 if (output_bytecode)
3561 bc_expand_decl_init (decl);
3565 /* If this is a CONST_DECL, we don't have to generate any code, but
3566 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3567 to be set while in the obstack containing the constant. If we don't
3568 do this, we can lose if we have functions nested three deep and the middle
3569 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3570 the innermost function is the first to expand that STRING_CST. */
3571 if (TREE_CODE (decl) == CONST_DECL)
3573 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3574 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3575 EXPAND_INITIALIZER);
3579 if (TREE_STATIC (decl))
3582 /* Compute and store the initial value now. */
3584 if (DECL_INITIAL (decl) == error_mark_node)
3586 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3587 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3588 || code == POINTER_TYPE)
3589 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3593 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3595 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3596 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3600 /* Don't let the initialization count as "using" the variable. */
3601 TREE_USED (decl) = was_used;
3603 /* Free any temporaries we made while initializing the decl. */
3604 preserve_temp_slots (NULL_RTX);
3608 /* Expand initialization for variable-sized types. Allocate array
3609 using newlocalSI and set local variable, which is a pointer to the
3613 bc_expand_variable_local_init (decl)
3616 /* Evaluate size expression and coerce to SI */
3617 bc_expand_expr (DECL_SIZE (decl));
3619 /* Type sizes are always (?) of TREE_CODE INTEGER_CST, so
3620 no coercion is necessary (?) */
3622 /* emit_typecode_conversion (preferred_typecode (TYPE_MODE (DECL_SIZE (decl)),
3623 TREE_UNSIGNED (DECL_SIZE (decl))), SIcode); */
3625 /* Emit code to allocate array */
3626 bc_emit_instruction (newlocalSI);
3628 /* Store array pointer in local variable. This is the only instance
3629 where we actually want the address of the pointer to the
3630 variable-size block, rather than the pointer itself. We avoid
3631 using expand_address() since that would cause the pointer to be
3632 pushed rather than its address. Hence the hard-coded reference;
3633 notice also that the variable is always local (no global
3634 variable-size type variables). */
3636 bc_load_localaddr (DECL_RTL (decl));
3637 bc_emit_instruction (storeP);
3641 /* Emit code to initialize a declaration. */
3644 bc_expand_decl_init (decl)
3647 int org_stack_depth;
3649 /* Statical initializers are handled elsewhere */
3651 if (TREE_STATIC (decl))
3654 /* Memory original stack depth */
3655 org_stack_depth = stack_depth;
3657 /* If the type is variable-size, we first create its space (we ASSUME
3658 it CAN'T be static). We do this regardless of whether there's an
3659 initializer assignment or not. */
3661 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
3662 bc_expand_variable_local_init (decl);
3664 /* Expand initializer assignment */
3665 if (DECL_INITIAL (decl) == error_mark_node)
3667 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3669 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3670 || code == POINTER_TYPE)
3672 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3674 else if (DECL_INITIAL (decl))
3675 expand_assignment (TREE_TYPE (decl), decl, 0, 0);
3677 /* Restore stack depth */
3678 if (org_stack_depth > stack_depth)
3681 bc_adjust_stack (stack_depth - org_stack_depth);
3685 /* CLEANUP is an expression to be executed at exit from this binding contour;
3686 for example, in C++, it might call the destructor for this variable.
3688 If CLEANUP contains any SAVE_EXPRs, then you must preevaluate them
3689 either before or after calling `expand_decl_cleanup' but before compiling
3690 any subsequent expressions. This is because CLEANUP may be expanded
3691 more than once, on different branches of execution.
3692 For the same reason, CLEANUP may not contain a CALL_EXPR
3693 except as its topmost node--else `preexpand_calls' would get confused.
3695 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3696 that is not associated with any particular variable. */
3699 expand_decl_cleanup (decl, cleanup)
3702 struct nesting *thisblock = block_stack;
3704 /* Error if we are not in any block. */
3708 /* Record the cleanup if there is one. */
3712 thisblock->data.block.cleanups
3713 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3714 /* If this block has a cleanup, it belongs in stack_block_stack. */
3715 stack_block_stack = thisblock;
3716 (*interim_eh_hook) (NULL_TREE);
3721 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3722 DECL_ELTS is the list of elements that belong to DECL's type.
3723 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3726 expand_anon_union_decl (decl, cleanup, decl_elts)
3727 tree decl, cleanup, decl_elts;
3729 struct nesting *thisblock = block_stack;
3733 expand_decl_cleanup (decl, cleanup);
3734 x = DECL_RTL (decl);
3738 tree decl_elt = TREE_VALUE (decl_elts);
3739 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3740 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3742 /* Propagate the union's alignment to the elements. */
3743 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3745 /* If the element has BLKmode and the union doesn't, the union is
3746 aligned such that the element doesn't need to have BLKmode, so
3747 change the element's mode to the appropriate one for its size. */
3748 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3749 DECL_MODE (decl_elt) = mode
3750 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3753 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3754 instead create a new MEM rtx with the proper mode. */
3755 if (GET_CODE (x) == MEM)
3757 if (mode == GET_MODE (x))
3758 DECL_RTL (decl_elt) = x;
3761 DECL_RTL (decl_elt) = gen_rtx (MEM, mode, copy_rtx (XEXP (x, 0)));
3762 MEM_IN_STRUCT_P (DECL_RTL (decl_elt)) = MEM_IN_STRUCT_P (x);
3763 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3766 else if (GET_CODE (x) == REG)
3768 if (mode == GET_MODE (x))
3769 DECL_RTL (decl_elt) = x;
3771 DECL_RTL (decl_elt) = gen_rtx (SUBREG, mode, x, 0);
3776 /* Record the cleanup if there is one. */
3779 thisblock->data.block.cleanups
3780 = temp_tree_cons (decl_elt, cleanup_elt,
3781 thisblock->data.block.cleanups);
3783 decl_elts = TREE_CHAIN (decl_elts);
3787 /* Expand a list of cleanups LIST.
3788 Elements may be expressions or may be nested lists.
3790 If DONT_DO is nonnull, then any list-element
3791 whose TREE_PURPOSE matches DONT_DO is omitted.
3792 This is sometimes used to avoid a cleanup associated with
3793 a value that is being returned out of the scope.
3795 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3796 goto and handle protection regions specially in that case.
3798 If REACHABLE, we emit code, otherwise just inform the exception handling
3799 code about this finalization. */
3802 expand_cleanups (list, dont_do, in_fixup, reachable)
3809 for (tail = list; tail; tail = TREE_CHAIN (tail))
3810 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3812 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3813 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3817 (*interim_eh_hook) (TREE_VALUE (tail));
3821 /* Cleanups may be run multiple times. For example,
3822 when exiting a binding contour, we expand the
3823 cleanups associated with that contour. When a goto
3824 within that binding contour has a target outside that
3825 contour, it will expand all cleanups from its scope to
3826 the target. Though the cleanups are expanded multiple
3827 times, the control paths are non-overlapping so the
3828 cleanups will not be executed twice. */
3829 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3836 /* Move all cleanups from the current block_stack
3837 to the containing block_stack, where they are assumed to
3838 have been created. If anything can cause a temporary to
3839 be created, but not expanded for more than one level of
3840 block_stacks, then this code will have to change. */
3845 struct nesting *block = block_stack;
3846 struct nesting *outer = block->next;
3848 outer->data.block.cleanups
3849 = chainon (block->data.block.cleanups,
3850 outer->data.block.cleanups);
3851 block->data.block.cleanups = 0;
3855 last_cleanup_this_contour ()
3857 if (block_stack == 0)
3860 return block_stack->data.block.cleanups;
3863 /* Return 1 if there are any pending cleanups at this point.
3864 If THIS_CONTOUR is nonzero, check the current contour as well.
3865 Otherwise, look only at the contours that enclose this one. */
3868 any_pending_cleanups (this_contour)
3871 struct nesting *block;
3873 if (block_stack == 0)
3876 if (this_contour && block_stack->data.block.cleanups != NULL)
3878 if (block_stack->data.block.cleanups == 0
3879 && (block_stack->data.block.outer_cleanups == 0
3881 || block_stack->data.block.outer_cleanups == empty_cleanup_list
3886 for (block = block_stack->next; block; block = block->next)
3887 if (block->data.block.cleanups != 0)
3893 /* Enter a case (Pascal) or switch (C) statement.
3894 Push a block onto case_stack and nesting_stack
3895 to accumulate the case-labels that are seen
3896 and to record the labels generated for the statement.
3898 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
3899 Otherwise, this construct is transparent for `exit_something'.
3901 EXPR is the index-expression to be dispatched on.
3902 TYPE is its nominal type. We could simply convert EXPR to this type,
3903 but instead we take short cuts. */
3906 expand_start_case (exit_flag, expr, type, printname)
3912 register struct nesting *thiscase = ALLOC_NESTING ();
3914 /* Make an entry on case_stack for the case we are entering. */
3916 thiscase->next = case_stack;
3917 thiscase->all = nesting_stack;
3918 thiscase->depth = ++nesting_depth;
3919 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
3920 thiscase->data.case_stmt.case_list = 0;
3921 thiscase->data.case_stmt.index_expr = expr;
3922 thiscase->data.case_stmt.nominal_type = type;
3923 thiscase->data.case_stmt.default_label = 0;
3924 thiscase->data.case_stmt.num_ranges = 0;
3925 thiscase->data.case_stmt.printname = printname;
3926 thiscase->data.case_stmt.seenlabel = 0;
3927 case_stack = thiscase;
3928 nesting_stack = thiscase;
3930 if (output_bytecode)
3932 bc_expand_start_case (thiscase, expr, type, printname);
3936 do_pending_stack_adjust ();
3938 /* Make sure case_stmt.start points to something that won't
3939 need any transformation before expand_end_case. */
3940 if (GET_CODE (get_last_insn ()) != NOTE)
3941 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3943 thiscase->data.case_stmt.start = get_last_insn ();
3947 /* Enter a case statement. It is assumed that the caller has pushed
3948 the current context onto the case stack. */
3951 bc_expand_start_case (thiscase, expr, type, printname)
3952 struct nesting *thiscase;
3957 bc_expand_expr (expr);
3958 bc_expand_conversion (TREE_TYPE (expr), type);
3960 /* For cases, the skip is a place we jump to that's emitted after
3961 the size of the jump table is known. */
3963 thiscase->data.case_stmt.skip_label = gen_label_rtx ();
3964 bc_emit_bytecode (jump);
3965 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
3967 #ifdef DEBUG_PRINT_CODE
3968 fputc ('\n', stderr);
3973 /* Start a "dummy case statement" within which case labels are invalid
3974 and are not connected to any larger real case statement.
3975 This can be used if you don't want to let a case statement jump
3976 into the middle of certain kinds of constructs. */
3979 expand_start_case_dummy ()
3981 register struct nesting *thiscase = ALLOC_NESTING ();
3983 /* Make an entry on case_stack for the dummy. */
3985 thiscase->next = case_stack;
3986 thiscase->all = nesting_stack;
3987 thiscase->depth = ++nesting_depth;
3988 thiscase->exit_label = 0;
3989 thiscase->data.case_stmt.case_list = 0;
3990 thiscase->data.case_stmt.start = 0;
3991 thiscase->data.case_stmt.nominal_type = 0;
3992 thiscase->data.case_stmt.default_label = 0;
3993 thiscase->data.case_stmt.num_ranges = 0;
3994 case_stack = thiscase;
3995 nesting_stack = thiscase;
3998 /* End a dummy case statement. */
4001 expand_end_case_dummy ()
4003 POPSTACK (case_stack);
4006 /* Return the data type of the index-expression
4007 of the innermost case statement, or null if none. */
4010 case_index_expr_type ()
4013 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4017 /* Accumulate one case or default label inside a case or switch statement.
4018 VALUE is the value of the case (a null pointer, for a default label).
4019 The function CONVERTER, when applied to arguments T and V,
4020 converts the value V to the type T.
4022 If not currently inside a case or switch statement, return 1 and do
4023 nothing. The caller will print a language-specific error message.
4024 If VALUE is a duplicate or overlaps, return 2 and do nothing
4025 except store the (first) duplicate node in *DUPLICATE.
4026 If VALUE is out of range, return 3 and do nothing.
4027 If we are jumping into the scope of a cleaup or var-sized array, return 5.
4028 Return 0 on success.
4030 Extended to handle range statements. */
4033 pushcase (value, converter, label, duplicate)
4034 register tree value;
4035 tree (*converter) PROTO((tree, tree));
4036 register tree label;
4039 register struct case_node **l;
4040 register struct case_node *n;
4044 if (output_bytecode)
4045 return bc_pushcase (value, label);
4047 /* Fail if not inside a real case statement. */
4048 if (! (case_stack && case_stack->data.case_stmt.start))
4051 if (stack_block_stack
4052 && stack_block_stack->depth > case_stack->depth)
4055 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4056 nominal_type = case_stack->data.case_stmt.nominal_type;
4058 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4059 if (index_type == error_mark_node)
4062 /* Convert VALUE to the type in which the comparisons are nominally done. */
4064 value = (*converter) (nominal_type, value);
4066 /* If this is the first label, warn if any insns have been emitted. */
4067 if (case_stack->data.case_stmt.seenlabel == 0)
4070 for (insn = case_stack->data.case_stmt.start;
4072 insn = NEXT_INSN (insn))
4074 if (GET_CODE (insn) == CODE_LABEL)
4076 if (GET_CODE (insn) != NOTE
4077 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4079 warning ("unreachable code at beginning of %s",
4080 case_stack->data.case_stmt.printname);
4085 case_stack->data.case_stmt.seenlabel = 1;
4087 /* Fail if this value is out of range for the actual type of the index
4088 (which may be narrower than NOMINAL_TYPE). */
4089 if (value != 0 && ! int_fits_type_p (value, index_type))
4092 /* Fail if this is a duplicate or overlaps another entry. */
4095 if (case_stack->data.case_stmt.default_label != 0)
4097 *duplicate = case_stack->data.case_stmt.default_label;
4100 case_stack->data.case_stmt.default_label = label;
4104 /* Find the elt in the chain before which to insert the new value,
4105 to keep the chain sorted in increasing order.
4106 But report an error if this element is a duplicate. */
4107 for (l = &case_stack->data.case_stmt.case_list;
4108 /* Keep going past elements distinctly less than VALUE. */
4109 *l != 0 && tree_int_cst_lt ((*l)->high, value);
4114 /* Element we will insert before must be distinctly greater;
4115 overlap means error. */
4116 if (! tree_int_cst_lt (value, (*l)->low))
4118 *duplicate = (*l)->code_label;
4123 /* Add this label to the chain, and succeed.
4124 Copy VALUE so it is on temporary rather than momentary
4125 obstack and will thus survive till the end of the case statement. */
4126 n = (struct case_node *) oballoc (sizeof (struct case_node));
4129 n->high = n->low = copy_node (value);
4130 n->code_label = label;
4134 expand_label (label);
4138 /* Like pushcase but this case applies to all values
4139 between VALUE1 and VALUE2 (inclusive).
4140 The return value is the same as that of pushcase
4141 but there is one additional error code:
4142 4 means the specified range was empty. */
4145 pushcase_range (value1, value2, converter, label, duplicate)
4146 register tree value1, value2;
4147 tree (*converter) PROTO((tree, tree));
4148 register tree label;
4151 register struct case_node **l;
4152 register struct case_node *n;
4156 /* Fail if not inside a real case statement. */
4157 if (! (case_stack && case_stack->data.case_stmt.start))
4160 if (stack_block_stack
4161 && stack_block_stack->depth > case_stack->depth)
4164 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4165 nominal_type = case_stack->data.case_stmt.nominal_type;
4167 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4168 if (index_type == error_mark_node)
4171 /* If this is the first label, warn if any insns have been emitted. */
4172 if (case_stack->data.case_stmt.seenlabel == 0)
4175 for (insn = case_stack->data.case_stmt.start;
4177 insn = NEXT_INSN (insn))
4179 if (GET_CODE (insn) == CODE_LABEL)
4181 if (GET_CODE (insn) != NOTE
4182 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4184 warning ("unreachable code at beginning of %s",
4185 case_stack->data.case_stmt.printname);
4190 case_stack->data.case_stmt.seenlabel = 1;
4192 /* Convert VALUEs to type in which the comparisons are nominally done. */
4193 if (value1 == 0) /* Negative infinity. */
4194 value1 = TYPE_MIN_VALUE(index_type);
4195 value1 = (*converter) (nominal_type, value1);
4197 if (value2 == 0) /* Positive infinity. */
4198 value2 = TYPE_MAX_VALUE(index_type);
4199 value2 = (*converter) (nominal_type, value2);
4201 /* Fail if these values are out of range. */
4202 if (! int_fits_type_p (value1, index_type))
4205 if (! int_fits_type_p (value2, index_type))
4208 /* Fail if the range is empty. */
4209 if (tree_int_cst_lt (value2, value1))
4212 /* If the bounds are equal, turn this into the one-value case. */
4213 if (tree_int_cst_equal (value1, value2))
4214 return pushcase (value1, converter, label, duplicate);
4216 /* Find the elt in the chain before which to insert the new value,
4217 to keep the chain sorted in increasing order.
4218 But report an error if this element is a duplicate. */
4219 for (l = &case_stack->data.case_stmt.case_list;
4220 /* Keep going past elements distinctly less than this range. */
4221 *l != 0 && tree_int_cst_lt ((*l)->high, value1);
4226 /* Element we will insert before must be distinctly greater;
4227 overlap means error. */
4228 if (! tree_int_cst_lt (value2, (*l)->low))
4230 *duplicate = (*l)->code_label;
4235 /* Add this label to the chain, and succeed.
4236 Copy VALUE1, VALUE2 so they are on temporary rather than momentary
4237 obstack and will thus survive till the end of the case statement. */
4239 n = (struct case_node *) oballoc (sizeof (struct case_node));
4242 n->low = copy_node (value1);
4243 n->high = copy_node (value2);
4244 n->code_label = label;
4247 expand_label (label);
4249 case_stack->data.case_stmt.num_ranges++;
4255 /* Accumulate one case or default label; VALUE is the value of the
4256 case, or nil for a default label. If not currently inside a case,
4257 return 1 and do nothing. If VALUE is a duplicate or overlaps, return
4258 2 and do nothing. If VALUE is out of range, return 3 and do nothing.
4259 Return 0 on success. This function is a leftover from the earlier
4260 bytecode compiler, which was based on gcc 1.37. It should be
4261 merged into pushcase. */
4264 bc_pushcase (value, label)
4268 struct nesting *thiscase = case_stack;
4269 struct case_node *case_label, *new_label;
4274 /* Fail if duplicate, overlap, or out of type range. */
4277 value = convert (thiscase->data.case_stmt.nominal_type, value);
4278 if (! int_fits_type_p (value, thiscase->data.case_stmt.nominal_type))
4281 for (case_label = thiscase->data.case_stmt.case_list;
4282 case_label->left; case_label = case_label->left)
4283 if (! tree_int_cst_lt (case_label->left->high, value))
4286 if (case_label != thiscase->data.case_stmt.case_list
4287 && ! tree_int_cst_lt (case_label->high, value)
4288 || case_label->left && ! tree_int_cst_lt (value, case_label->left->low))
4291 new_label = (struct case_node *) oballoc (sizeof (struct case_node));
4292 new_label->low = new_label->high = copy_node (value);
4293 new_label->code_label = label;
4294 new_label->left = case_label->left;
4296 case_label->left = new_label;
4297 thiscase->data.case_stmt.num_ranges++;
4301 if (thiscase->data.case_stmt.default_label)
4303 thiscase->data.case_stmt.default_label = label;
4306 expand_label (label);
4310 /* Returns the number of possible values of TYPE.
4311 Returns -1 if the number is unknown or variable.
4312 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4313 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4314 do not increase monotonically (there may be duplicates);
4315 to 1 if the values increase monotonically, but not always by 1;
4316 otherwise sets it to 0. */
4319 all_cases_count (type, spareness)
4323 HOST_WIDE_INT count, count_high = 0;
4326 switch (TREE_CODE (type))
4333 count = 1 << BITS_PER_UNIT;
4337 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4338 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4343 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4344 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4345 but with overflow checking. */
4346 tree mint = TYPE_MIN_VALUE (type);
4347 tree maxt = TYPE_MAX_VALUE (type);
4348 HOST_WIDE_INT lo, hi;
4349 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4351 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4353 add_double (lo, hi, 1, 0, &lo, &hi);
4354 if (hi != 0 || lo < 0)
4361 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4363 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4364 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4365 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4366 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4370 if (*spareness == 1)
4372 tree prev = TREE_VALUE (TYPE_VALUES (type));
4373 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4375 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4380 prev = TREE_VALUE (t);
4389 #define BITARRAY_TEST(ARRAY, INDEX) \
4390 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4391 & (1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR)))
4392 #define BITARRAY_SET(ARRAY, INDEX) \
4393 ((ARRAY)[(unsigned)(INDEX) / HOST_BITS_PER_CHAR]\
4394 |= 1 << ((unsigned)(INDEX) % HOST_BITS_PER_CHAR))
4396 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4397 with the case values we have seen, assuming the case expression
4399 SPARSENESS is as determined by all_cases_count.
4401 The time needed is proportional to COUNT, unless
4402 SPARSENESS is 2, in which case quadratic time is needed. */
4405 mark_seen_cases (type, cases_seen, count, sparseness)
4407 unsigned char *cases_seen;
4413 tree next_node_to_try = NULL_TREE;
4414 long next_node_offset = 0;
4416 register struct case_node *n;
4417 tree val = make_node (INTEGER_CST);
4418 TREE_TYPE (val) = type;
4419 for (n = case_stack->data.case_stmt.case_list; n;
4422 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4423 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4424 while ( ! tree_int_cst_lt (n->high, val))
4426 /* Calculate (into xlo) the "offset" of the integer (val).
4427 The element with lowest value has offset 0, the next smallest
4428 element has offset 1, etc. */
4430 HOST_WIDE_INT xlo, xhi;
4432 if (sparseness == 2)
4434 /* This less efficient loop is only needed to handle
4435 duplicate case values (multiple enum constants
4436 with the same value). */
4437 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4438 t = TREE_CHAIN (t), xlo++)
4440 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4441 BITARRAY_SET (cases_seen, xlo);
4446 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4448 /* The TYPE_VALUES will be in increasing order, so
4449 starting searching where we last ended. */
4450 t = next_node_to_try;
4451 xlo = next_node_offset;
4457 t = TYPE_VALUES (type);
4460 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4462 next_node_to_try = TREE_CHAIN (t);
4463 next_node_offset = xlo + 1;
4468 if (t == next_node_to_try)
4474 t = TYPE_MIN_VALUE (type);
4476 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4480 add_double (xlo, xhi,
4481 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4485 if (xhi == 0 && xlo >= 0 && xlo < count)
4486 BITARRAY_SET (cases_seen, xlo);
4488 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4490 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4495 /* Called when the index of a switch statement is an enumerated type
4496 and there is no default label.
4498 Checks that all enumeration literals are covered by the case
4499 expressions of a switch. Also, warn if there are any extra
4500 switch cases that are *not* elements of the enumerated type.
4502 If all enumeration literals were covered by the case expressions,
4503 turn one of the expressions into the default expression since it should
4504 not be possible to fall through such a switch. */
4507 check_for_full_enumeration_handling (type)
4510 register struct case_node *n;
4511 register struct case_node **l;
4512 register tree chain;
4515 /* True iff the selector type is a numbered set mode. */
4518 /* The number of possible selector values. */
4521 /* For each possible selector value. a one iff it has been matched
4522 by a case value alternative. */
4523 unsigned char *cases_seen;
4525 /* The allocated size of cases_seen, in chars. */
4529 if (output_bytecode)
4531 bc_check_for_full_enumeration_handling (type);
4538 size = all_cases_count (type, &sparseness);
4539 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4541 if (size > 0 && size < 600000
4542 /* We deliberately use malloc here - not xmalloc. */
4543 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4546 tree v = TYPE_VALUES (type);
4547 bzero (cases_seen, bytes_needed);
4549 /* The time complexity of this code is normally O(N), where
4550 N being the number of members in the enumerated type.
4551 However, if type is a ENUMERAL_TYPE whose values do not
4552 increase monotonically, quadratic time may be needed. */
4554 mark_seen_cases (type, cases_seen, size, sparseness);
4556 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4558 if (BITARRAY_TEST(cases_seen, i) == 0)
4559 warning ("enumeration value `%s' not handled in switch",
4560 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4566 /* Now we go the other way around; we warn if there are case
4567 expressions that don't correspond to enumerators. This can
4568 occur since C and C++ don't enforce type-checking of
4569 assignments to enumeration variables. */
4572 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4574 for (chain = TYPE_VALUES (type);
4575 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4576 chain = TREE_CHAIN (chain))
4581 if (TYPE_NAME (type) == 0)
4582 warning ("case value `%d' not in enumerated type",
4583 TREE_INT_CST_LOW (n->low));
4585 warning ("case value `%d' not in enumerated type `%s'",
4586 TREE_INT_CST_LOW (n->low),
4587 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4590 : DECL_NAME (TYPE_NAME (type))));
4592 if (!tree_int_cst_equal (n->low, n->high))
4594 for (chain = TYPE_VALUES (type);
4595 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4596 chain = TREE_CHAIN (chain))
4601 if (TYPE_NAME (type) == 0)
4602 warning ("case value `%d' not in enumerated type",
4603 TREE_INT_CST_LOW (n->high));
4605 warning ("case value `%d' not in enumerated type `%s'",
4606 TREE_INT_CST_LOW (n->high),
4607 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4610 : DECL_NAME (TYPE_NAME (type))));
4616 /* ??? This optimization is disabled because it causes valid programs to
4617 fail. ANSI C does not guarantee that an expression with enum type
4618 will have a value that is the same as one of the enumeration literals. */
4620 /* If all values were found as case labels, make one of them the default
4621 label. Thus, this switch will never fall through. We arbitrarily pick
4622 the last one to make the default since this is likely the most
4623 efficient choice. */
4627 for (l = &case_stack->data.case_stmt.case_list;
4632 case_stack->data.case_stmt.default_label = (*l)->code_label;
4639 /* Check that all enumeration literals are covered by the case
4640 expressions of a switch. Also warn if there are any cases
4641 that are not elements of the enumerated type. */
4644 bc_check_for_full_enumeration_handling (type)
4647 struct nesting *thiscase = case_stack;
4648 struct case_node *c;
4651 /* Check for enums not handled. */
4652 for (e = TYPE_VALUES (type); e; e = TREE_CHAIN (e))
4654 for (c = thiscase->data.case_stmt.case_list->left;
4655 c && tree_int_cst_lt (c->high, TREE_VALUE (e));
4658 if (! (c && tree_int_cst_equal (c->low, TREE_VALUE (e))))
4659 warning ("enumerated value `%s' not handled in switch",
4660 IDENTIFIER_POINTER (TREE_PURPOSE (e)));
4663 /* Check for cases not in the enumeration. */
4664 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
4666 for (e = TYPE_VALUES (type);
4667 e && !tree_int_cst_equal (c->low, TREE_VALUE (e));
4671 warning ("case value `%d' not in enumerated type `%s'",
4672 TREE_INT_CST_LOW (c->low),
4673 IDENTIFIER_POINTER (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE
4675 : DECL_NAME (TYPE_NAME (type))));
4679 /* Terminate a case (Pascal) or switch (C) statement
4680 in which ORIG_INDEX is the expression to be tested.
4681 Generate the code to test it and jump to the right place. */
4684 expand_end_case (orig_index)
4687 tree minval, maxval, range, orig_minval;
4688 rtx default_label = 0;
4689 register struct case_node *n;
4697 register struct nesting *thiscase = case_stack;
4698 tree index_expr, index_type;
4701 if (output_bytecode)
4703 bc_expand_end_case (orig_index);
4707 table_label = gen_label_rtx ();
4708 index_expr = thiscase->data.case_stmt.index_expr;
4709 index_type = TREE_TYPE (index_expr);
4710 unsignedp = TREE_UNSIGNED (index_type);
4712 do_pending_stack_adjust ();
4714 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4715 if (index_type != error_mark_node)
4717 /* If switch expression was an enumerated type, check that all
4718 enumeration literals are covered by the cases.
4719 No sense trying this if there's a default case, however. */
4721 if (!thiscase->data.case_stmt.default_label
4722 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4723 && TREE_CODE (index_expr) != INTEGER_CST)
4724 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4726 /* If this is the first label, warn if any insns have been emitted. */
4727 if (thiscase->data.case_stmt.seenlabel == 0)
4730 for (insn = get_last_insn ();
4731 insn != case_stack->data.case_stmt.start;
4732 insn = PREV_INSN (insn))
4733 if (GET_CODE (insn) != NOTE
4734 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn))!= USE))
4736 warning ("unreachable code at beginning of %s",
4737 case_stack->data.case_stmt.printname);
4742 /* If we don't have a default-label, create one here,
4743 after the body of the switch. */
4744 if (thiscase->data.case_stmt.default_label == 0)
4746 thiscase->data.case_stmt.default_label
4747 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4748 expand_label (thiscase->data.case_stmt.default_label);
4750 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4752 before_case = get_last_insn ();
4754 /* Simplify the case-list before we count it. */
4755 group_case_nodes (thiscase->data.case_stmt.case_list);
4757 /* Get upper and lower bounds of case values.
4758 Also convert all the case values to the index expr's data type. */
4761 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4763 /* Check low and high label values are integers. */
4764 if (TREE_CODE (n->low) != INTEGER_CST)
4766 if (TREE_CODE (n->high) != INTEGER_CST)
4769 n->low = convert (index_type, n->low);
4770 n->high = convert (index_type, n->high);
4772 /* Count the elements and track the largest and smallest
4773 of them (treating them as signed even if they are not). */
4781 if (INT_CST_LT (n->low, minval))
4783 if (INT_CST_LT (maxval, n->high))
4786 /* A range counts double, since it requires two compares. */
4787 if (! tree_int_cst_equal (n->low, n->high))
4791 orig_minval = minval;
4793 /* Compute span of values. */
4795 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
4799 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
4801 emit_jump (default_label);
4804 /* If range of values is much bigger than number of values,
4805 make a sequence of conditional branches instead of a dispatch.
4806 If the switch-index is a constant, do it this way
4807 because we can optimize it. */
4809 #ifndef CASE_VALUES_THRESHOLD
4811 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
4813 /* If machine does not have a case insn that compares the
4814 bounds, this means extra overhead for dispatch tables
4815 which raises the threshold for using them. */
4816 #define CASE_VALUES_THRESHOLD 5
4817 #endif /* HAVE_casesi */
4818 #endif /* CASE_VALUES_THRESHOLD */
4820 else if (TREE_INT_CST_HIGH (range) != 0
4821 || count < CASE_VALUES_THRESHOLD
4822 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
4824 || TREE_CODE (index_expr) == INTEGER_CST
4825 /* These will reduce to a constant. */
4826 || (TREE_CODE (index_expr) == CALL_EXPR
4827 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
4828 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
4829 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
4830 || (TREE_CODE (index_expr) == COMPOUND_EXPR
4831 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
4833 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4835 /* If the index is a short or char that we do not have
4836 an insn to handle comparisons directly, convert it to
4837 a full integer now, rather than letting each comparison
4838 generate the conversion. */
4840 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
4841 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
4842 == CODE_FOR_nothing))
4844 enum machine_mode wider_mode;
4845 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
4846 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
4847 if (cmp_optab->handlers[(int) wider_mode].insn_code
4848 != CODE_FOR_nothing)
4850 index = convert_to_mode (wider_mode, index, unsignedp);
4856 do_pending_stack_adjust ();
4858 index = protect_from_queue (index, 0);
4859 if (GET_CODE (index) == MEM)
4860 index = copy_to_reg (index);
4861 if (GET_CODE (index) == CONST_INT
4862 || TREE_CODE (index_expr) == INTEGER_CST)
4864 /* Make a tree node with the proper constant value
4865 if we don't already have one. */
4866 if (TREE_CODE (index_expr) != INTEGER_CST)
4869 = build_int_2 (INTVAL (index),
4870 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
4871 index_expr = convert (index_type, index_expr);
4874 /* For constant index expressions we need only
4875 issue a unconditional branch to the appropriate
4876 target code. The job of removing any unreachable
4877 code is left to the optimisation phase if the
4878 "-O" option is specified. */
4879 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
4880 if (! tree_int_cst_lt (index_expr, n->low)
4881 && ! tree_int_cst_lt (n->high, index_expr))
4885 emit_jump (label_rtx (n->code_label));
4887 emit_jump (default_label);
4891 /* If the index expression is not constant we generate
4892 a binary decision tree to select the appropriate
4893 target code. This is done as follows:
4895 The list of cases is rearranged into a binary tree,
4896 nearly optimal assuming equal probability for each case.
4898 The tree is transformed into RTL, eliminating
4899 redundant test conditions at the same time.
4901 If program flow could reach the end of the
4902 decision tree an unconditional jump to the
4903 default code is emitted. */
4906 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
4907 && estimate_case_costs (thiscase->data.case_stmt.case_list));
4908 balance_case_nodes (&thiscase->data.case_stmt.case_list,
4910 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
4911 default_label, index_type);
4912 emit_jump_if_reachable (default_label);
4921 enum machine_mode index_mode = SImode;
4922 int index_bits = GET_MODE_BITSIZE (index_mode);
4924 enum machine_mode op_mode;
4926 /* Convert the index to SImode. */
4927 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
4928 > GET_MODE_BITSIZE (index_mode))
4930 enum machine_mode omode = TYPE_MODE (index_type);
4931 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
4933 /* We must handle the endpoints in the original mode. */
4934 index_expr = build (MINUS_EXPR, index_type,
4935 index_expr, minval);
4936 minval = integer_zero_node;
4937 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4938 emit_cmp_insn (rangertx, index, LTU, NULL_RTX, omode, 1, 0);
4939 emit_jump_insn (gen_bltu (default_label));
4940 /* Now we can safely truncate. */
4941 index = convert_to_mode (index_mode, index, 0);
4945 if (TYPE_MODE (index_type) != index_mode)
4947 index_expr = convert (type_for_size (index_bits, 0),
4949 index_type = TREE_TYPE (index_expr);
4952 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4955 index = protect_from_queue (index, 0);
4956 do_pending_stack_adjust ();
4958 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
4959 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
4961 index = copy_to_mode_reg (op_mode, index);
4963 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
4965 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
4966 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
4968 op1 = copy_to_mode_reg (op_mode, op1);
4970 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
4972 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
4973 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
4975 op2 = copy_to_mode_reg (op_mode, op2);
4977 emit_jump_insn (gen_casesi (index, op1, op2,
4978 table_label, default_label));
4982 #ifdef HAVE_tablejump
4983 if (! win && HAVE_tablejump)
4985 index_expr = convert (thiscase->data.case_stmt.nominal_type,
4986 fold (build (MINUS_EXPR, index_type,
4987 index_expr, minval)));
4988 index_type = TREE_TYPE (index_expr);
4989 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
4991 index = protect_from_queue (index, 0);
4992 do_pending_stack_adjust ();
4994 do_tablejump (index, TYPE_MODE (index_type),
4995 expand_expr (range, NULL_RTX, VOIDmode, 0),
4996 table_label, default_label);
5003 /* Get table of labels to jump to, in order of case index. */
5005 ncases = TREE_INT_CST_LOW (range) + 1;
5006 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5007 bzero ((char *) labelvec, ncases * sizeof (rtx));
5009 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5011 register HOST_WIDE_INT i
5012 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5017 = gen_rtx (LABEL_REF, Pmode, label_rtx (n->code_label));
5018 if (i + TREE_INT_CST_LOW (orig_minval)
5019 == TREE_INT_CST_LOW (n->high))
5025 /* Fill in the gaps with the default. */
5026 for (i = 0; i < ncases; i++)
5027 if (labelvec[i] == 0)
5028 labelvec[i] = gen_rtx (LABEL_REF, Pmode, default_label);
5030 /* Output the table */
5031 emit_label (table_label);
5033 /* This would be a lot nicer if CASE_VECTOR_PC_RELATIVE
5034 were an expression, instead of an #ifdef/#ifndef. */
5036 #ifdef CASE_VECTOR_PC_RELATIVE
5040 emit_jump_insn (gen_rtx (ADDR_DIFF_VEC, CASE_VECTOR_MODE,
5041 gen_rtx (LABEL_REF, Pmode, table_label),
5042 gen_rtvec_v (ncases, labelvec)));
5044 emit_jump_insn (gen_rtx (ADDR_VEC, CASE_VECTOR_MODE,
5045 gen_rtvec_v (ncases, labelvec)));
5047 /* If the case insn drops through the table,
5048 after the table we must jump to the default-label.
5049 Otherwise record no drop-through after the table. */
5050 #ifdef CASE_DROPS_THROUGH
5051 emit_jump (default_label);
5057 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5058 reorder_insns (before_case, get_last_insn (),
5059 thiscase->data.case_stmt.start);
5062 if (thiscase->exit_label)
5063 emit_label (thiscase->exit_label);
5065 POPSTACK (case_stack);
5071 /* Terminate a case statement. EXPR is the original index
5075 bc_expand_end_case (expr)
5078 struct nesting *thiscase = case_stack;
5079 enum bytecode_opcode opcode;
5080 struct bc_label *jump_label;
5081 struct case_node *c;
5083 bc_emit_bytecode (jump);
5084 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5086 #ifdef DEBUG_PRINT_CODE
5087 fputc ('\n', stderr);
5090 /* Now that the size of the jump table is known, emit the actual
5091 indexed jump instruction. */
5092 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->data.case_stmt.skip_label));
5094 opcode = TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode
5095 ? TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseSU : caseSI
5096 : TREE_UNSIGNED (thiscase->data.case_stmt.nominal_type) ? caseDU : caseDI;
5098 bc_emit_bytecode (opcode);
5100 /* Now emit the case instructions literal arguments, in order.
5101 In addition to the value on the stack, it uses:
5102 1. The address of the jump table.
5103 2. The size of the jump table.
5104 3. The default label. */
5106 jump_label = bc_get_bytecode_label ();
5107 bc_emit_bytecode_labelref (jump_label);
5108 bc_emit_bytecode_const ((char *) &thiscase->data.case_stmt.num_ranges,
5109 sizeof thiscase->data.case_stmt.num_ranges);
5111 if (thiscase->data.case_stmt.default_label)
5112 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (thiscase->data.case_stmt.default_label)));
5114 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscase->exit_label));
5116 /* Output the jump table. */
5118 bc_align_bytecode (3 /* PTR_ALIGN */);
5119 bc_emit_bytecode_labeldef (jump_label);
5121 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == SImode)
5122 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5124 opcode = TREE_INT_CST_LOW (c->low);
5125 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5127 opcode = TREE_INT_CST_LOW (c->high);
5128 bc_emit_bytecode_const ((char *) &opcode, sizeof opcode);
5130 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5133 if (TYPE_MODE (thiscase->data.case_stmt.nominal_type) == DImode)
5134 for (c = thiscase->data.case_stmt.case_list->left; c; c = c->left)
5136 bc_emit_bytecode_DI_const (c->low);
5137 bc_emit_bytecode_DI_const (c->high);
5139 bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (DECL_RTL (c->code_label)));
5146 bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscase->exit_label));
5148 /* Possibly issue enumeration warnings. */
5150 if (!thiscase->data.case_stmt.default_label
5151 && TREE_CODE (TREE_TYPE (expr)) == ENUMERAL_TYPE
5152 && TREE_CODE (expr) != INTEGER_CST
5154 check_for_full_enumeration_handling (TREE_TYPE (expr));
5157 #ifdef DEBUG_PRINT_CODE
5158 fputc ('\n', stderr);
5161 POPSTACK (case_stack);
5165 /* Return unique bytecode ID. */
5170 static int bc_uid = 0;
5175 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5178 do_jump_if_equal (op1, op2, label, unsignedp)
5179 rtx op1, op2, label;
5182 if (GET_CODE (op1) == CONST_INT
5183 && GET_CODE (op2) == CONST_INT)
5185 if (INTVAL (op1) == INTVAL (op2))
5190 enum machine_mode mode = GET_MODE (op1);
5191 if (mode == VOIDmode)
5192 mode = GET_MODE (op2);
5193 emit_cmp_insn (op1, op2, EQ, NULL_RTX, mode, unsignedp, 0);
5194 emit_jump_insn (gen_beq (label));
5198 /* Not all case values are encountered equally. This function
5199 uses a heuristic to weight case labels, in cases where that
5200 looks like a reasonable thing to do.
5202 Right now, all we try to guess is text, and we establish the
5205 chars above space: 16
5214 If we find any cases in the switch that are not either -1 or in the range
5215 of valid ASCII characters, or are control characters other than those
5216 commonly used with "\", don't treat this switch scanning text.
5218 Return 1 if these nodes are suitable for cost estimation, otherwise
5222 estimate_case_costs (node)
5225 tree min_ascii = build_int_2 (-1, -1);
5226 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5230 /* If we haven't already made the cost table, make it now. Note that the
5231 lower bound of the table is -1, not zero. */
5233 if (cost_table == NULL)
5235 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5236 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5238 for (i = 0; i < 128; i++)
5242 else if (ispunct (i))
5244 else if (iscntrl (i))
5248 cost_table[' '] = 8;
5249 cost_table['\t'] = 4;
5250 cost_table['\0'] = 4;
5251 cost_table['\n'] = 2;
5252 cost_table['\f'] = 1;
5253 cost_table['\v'] = 1;
5254 cost_table['\b'] = 1;
5257 /* See if all the case expressions look like text. It is text if the
5258 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5259 as signed arithmetic since we don't want to ever access cost_table with a
5260 value less than -1. Also check that none of the constants in a range
5261 are strange control characters. */
5263 for (n = node; n; n = n->right)
5265 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5268 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5269 if (cost_table[i] < 0)
5273 /* All interesting values are within the range of interesting
5274 ASCII characters. */
5278 /* Scan an ordered list of case nodes
5279 combining those with consecutive values or ranges.
5281 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5284 group_case_nodes (head)
5287 case_node_ptr node = head;
5291 rtx lb = next_real_insn (label_rtx (node->code_label));
5292 case_node_ptr np = node;
5294 /* Try to group the successors of NODE with NODE. */
5295 while (((np = np->right) != 0)
5296 /* Do they jump to the same place? */
5297 && next_real_insn (label_rtx (np->code_label)) == lb
5298 /* Are their ranges consecutive? */
5299 && tree_int_cst_equal (np->low,
5300 fold (build (PLUS_EXPR,
5301 TREE_TYPE (node->high),
5304 /* An overflow is not consecutive. */
5305 && tree_int_cst_lt (node->high,
5306 fold (build (PLUS_EXPR,
5307 TREE_TYPE (node->high),
5309 integer_one_node))))
5311 node->high = np->high;
5313 /* NP is the first node after NODE which can't be grouped with it.
5314 Delete the nodes in between, and move on to that node. */
5320 /* Take an ordered list of case nodes
5321 and transform them into a near optimal binary tree,
5322 on the assumption that any target code selection value is as
5323 likely as any other.
5325 The transformation is performed by splitting the ordered
5326 list into two equal sections plus a pivot. The parts are
5327 then attached to the pivot as left and right branches. Each
5328 branch is is then transformed recursively. */
5331 balance_case_nodes (head, parent)
5332 case_node_ptr *head;
5333 case_node_ptr parent;
5335 register case_node_ptr np;
5343 register case_node_ptr *npp;
5346 /* Count the number of entries on branch. Also count the ranges. */
5350 if (!tree_int_cst_equal (np->low, np->high))
5354 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5358 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5366 /* Split this list if it is long enough for that to help. */
5371 /* Find the place in the list that bisects the list's total cost,
5372 Here I gets half the total cost. */
5377 /* Skip nodes while their cost does not reach that amount. */
5378 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5379 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5380 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5383 npp = &(*npp)->right;
5388 /* Leave this branch lopsided, but optimize left-hand
5389 side and fill in `parent' fields for right-hand side. */
5391 np->parent = parent;
5392 balance_case_nodes (&np->left, np);
5393 for (; np->right; np = np->right)
5394 np->right->parent = np;
5398 /* If there are just three nodes, split at the middle one. */
5400 npp = &(*npp)->right;
5403 /* Find the place in the list that bisects the list's total cost,
5404 where ranges count as 2.
5405 Here I gets half the total cost. */
5406 i = (i + ranges + 1) / 2;
5409 /* Skip nodes while their cost does not reach that amount. */
5410 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5415 npp = &(*npp)->right;
5420 np->parent = parent;
5423 /* Optimize each of the two split parts. */
5424 balance_case_nodes (&np->left, np);
5425 balance_case_nodes (&np->right, np);
5429 /* Else leave this branch as one level,
5430 but fill in `parent' fields. */
5432 np->parent = parent;
5433 for (; np->right; np = np->right)
5434 np->right->parent = np;
5439 /* Search the parent sections of the case node tree
5440 to see if a test for the lower bound of NODE would be redundant.
5441 INDEX_TYPE is the type of the index expression.
5443 The instructions to generate the case decision tree are
5444 output in the same order as nodes are processed so it is
5445 known that if a parent node checks the range of the current
5446 node minus one that the current node is bounded at its lower
5447 span. Thus the test would be redundant. */
5450 node_has_low_bound (node, index_type)
5455 case_node_ptr pnode;
5457 /* If the lower bound of this node is the lowest value in the index type,
5458 we need not test it. */
5460 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5463 /* If this node has a left branch, the value at the left must be less
5464 than that at this node, so it cannot be bounded at the bottom and
5465 we need not bother testing any further. */
5470 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5471 node->low, integer_one_node));
5473 /* If the subtraction above overflowed, we can't verify anything.
5474 Otherwise, look for a parent that tests our value - 1. */
5476 if (! tree_int_cst_lt (low_minus_one, node->low))
5479 for (pnode = node->parent; pnode; pnode = pnode->parent)
5480 if (tree_int_cst_equal (low_minus_one, pnode->high))
5486 /* Search the parent sections of the case node tree
5487 to see if a test for the upper bound of NODE would be redundant.
5488 INDEX_TYPE is the type of the index expression.
5490 The instructions to generate the case decision tree are
5491 output in the same order as nodes are processed so it is
5492 known that if a parent node checks the range of the current
5493 node plus one that the current node is bounded at its upper
5494 span. Thus the test would be redundant. */
5497 node_has_high_bound (node, index_type)
5502 case_node_ptr pnode;
5504 /* If the upper bound of this node is the highest value in the type
5505 of the index expression, we need not test against it. */
5507 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5510 /* If this node has a right branch, the value at the right must be greater
5511 than that at this node, so it cannot be bounded at the top and
5512 we need not bother testing any further. */
5517 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5518 node->high, integer_one_node));
5520 /* If the addition above overflowed, we can't verify anything.
5521 Otherwise, look for a parent that tests our value + 1. */
5523 if (! tree_int_cst_lt (node->high, high_plus_one))
5526 for (pnode = node->parent; pnode; pnode = pnode->parent)
5527 if (tree_int_cst_equal (high_plus_one, pnode->low))
5533 /* Search the parent sections of the
5534 case node tree to see if both tests for the upper and lower
5535 bounds of NODE would be redundant. */
5538 node_is_bounded (node, index_type)
5542 return (node_has_low_bound (node, index_type)
5543 && node_has_high_bound (node, index_type));
5546 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5549 emit_jump_if_reachable (label)
5552 if (GET_CODE (get_last_insn ()) != BARRIER)
5556 /* Emit step-by-step code to select a case for the value of INDEX.
5557 The thus generated decision tree follows the form of the
5558 case-node binary tree NODE, whose nodes represent test conditions.
5559 INDEX_TYPE is the type of the index of the switch.
5561 Care is taken to prune redundant tests from the decision tree
5562 by detecting any boundary conditions already checked by
5563 emitted rtx. (See node_has_high_bound, node_has_low_bound
5564 and node_is_bounded, above.)
5566 Where the test conditions can be shown to be redundant we emit
5567 an unconditional jump to the target code. As a further
5568 optimization, the subordinates of a tree node are examined to
5569 check for bounded nodes. In this case conditional and/or
5570 unconditional jumps as a result of the boundary check for the
5571 current node are arranged to target the subordinates associated
5572 code for out of bound conditions on the current node node.
5574 We can assume that when control reaches the code generated here,
5575 the index value has already been compared with the parents
5576 of this node, and determined to be on the same side of each parent
5577 as this node is. Thus, if this node tests for the value 51,
5578 and a parent tested for 52, we don't need to consider
5579 the possibility of a value greater than 51. If another parent
5580 tests for the value 50, then this node need not test anything. */
5583 emit_case_nodes (index, node, default_label, index_type)
5589 /* If INDEX has an unsigned type, we must make unsigned branches. */
5590 int unsignedp = TREE_UNSIGNED (index_type);
5591 typedef rtx rtx_function ();
5592 rtx_function *gen_bgt_pat = unsignedp ? gen_bgtu : gen_bgt;
5593 rtx_function *gen_bge_pat = unsignedp ? gen_bgeu : gen_bge;
5594 rtx_function *gen_blt_pat = unsignedp ? gen_bltu : gen_blt;
5595 rtx_function *gen_ble_pat = unsignedp ? gen_bleu : gen_ble;
5596 enum machine_mode mode = GET_MODE (index);
5598 /* See if our parents have already tested everything for us.
5599 If they have, emit an unconditional jump for this node. */
5600 if (node_is_bounded (node, index_type))
5601 emit_jump (label_rtx (node->code_label));
5603 else if (tree_int_cst_equal (node->low, node->high))
5605 /* Node is single valued. First see if the index expression matches
5606 this node and then check our children, if any. */
5608 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5609 label_rtx (node->code_label), unsignedp);
5611 if (node->right != 0 && node->left != 0)
5613 /* This node has children on both sides.
5614 Dispatch to one side or the other
5615 by comparing the index value with this node's value.
5616 If one subtree is bounded, check that one first,
5617 so we can avoid real branches in the tree. */
5619 if (node_is_bounded (node->right, index_type))
5621 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5623 GT, NULL_RTX, mode, unsignedp, 0);
5625 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5626 emit_case_nodes (index, node->left, default_label, index_type);
5629 else if (node_is_bounded (node->left, index_type))
5631 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5633 LT, NULL_RTX, mode, unsignedp, 0);
5634 emit_jump_insn ((*gen_blt_pat) (label_rtx (node->left->code_label)));
5635 emit_case_nodes (index, node->right, default_label, index_type);
5640 /* Neither node is bounded. First distinguish the two sides;
5641 then emit the code for one side at a time. */
5644 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5646 /* See if the value is on the right. */
5647 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5649 GT, NULL_RTX, mode, unsignedp, 0);
5650 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5652 /* Value must be on the left.
5653 Handle the left-hand subtree. */
5654 emit_case_nodes (index, node->left, default_label, index_type);
5655 /* If left-hand subtree does nothing,
5657 emit_jump_if_reachable (default_label);
5659 /* Code branches here for the right-hand subtree. */
5660 expand_label (test_label);
5661 emit_case_nodes (index, node->right, default_label, index_type);
5665 else if (node->right != 0 && node->left == 0)
5667 /* Here we have a right child but no left so we issue conditional
5668 branch to default and process the right child.
5670 Omit the conditional branch to default if we it avoid only one
5671 right child; it costs too much space to save so little time. */
5673 if (node->right->right || node->right->left
5674 || !tree_int_cst_equal (node->right->low, node->right->high))
5676 if (!node_has_low_bound (node, index_type))
5678 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5680 LT, NULL_RTX, mode, unsignedp, 0);
5681 emit_jump_insn ((*gen_blt_pat) (default_label));
5684 emit_case_nodes (index, node->right, default_label, index_type);
5687 /* We cannot process node->right normally
5688 since we haven't ruled out the numbers less than
5689 this node's value. So handle node->right explicitly. */
5690 do_jump_if_equal (index,
5691 expand_expr (node->right->low, NULL_RTX,
5693 label_rtx (node->right->code_label), unsignedp);
5696 else if (node->right == 0 && node->left != 0)
5698 /* Just one subtree, on the left. */
5700 #if 0 /* The following code and comment were formerly part
5701 of the condition here, but they didn't work
5702 and I don't understand what the idea was. -- rms. */
5703 /* If our "most probable entry" is less probable
5704 than the default label, emit a jump to
5705 the default label using condition codes
5706 already lying around. With no right branch,
5707 a branch-greater-than will get us to the default
5710 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5713 if (node->left->left || node->left->right
5714 || !tree_int_cst_equal (node->left->low, node->left->high))
5716 if (!node_has_high_bound (node, index_type))
5718 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5720 GT, NULL_RTX, mode, unsignedp, 0);
5721 emit_jump_insn ((*gen_bgt_pat) (default_label));
5724 emit_case_nodes (index, node->left, default_label, index_type);
5727 /* We cannot process node->left normally
5728 since we haven't ruled out the numbers less than
5729 this node's value. So handle node->left explicitly. */
5730 do_jump_if_equal (index,
5731 expand_expr (node->left->low, NULL_RTX,
5733 label_rtx (node->left->code_label), unsignedp);
5738 /* Node is a range. These cases are very similar to those for a single
5739 value, except that we do not start by testing whether this node
5740 is the one to branch to. */
5742 if (node->right != 0 && node->left != 0)
5744 /* Node has subtrees on both sides.
5745 If the right-hand subtree is bounded,
5746 test for it first, since we can go straight there.
5747 Otherwise, we need to make a branch in the control structure,
5748 then handle the two subtrees. */
5749 tree test_label = 0;
5751 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5753 GT, NULL_RTX, mode, unsignedp, 0);
5755 if (node_is_bounded (node->right, index_type))
5756 /* Right hand node is fully bounded so we can eliminate any
5757 testing and branch directly to the target code. */
5758 emit_jump_insn ((*gen_bgt_pat) (label_rtx (node->right->code_label)));
5761 /* Right hand node requires testing.
5762 Branch to a label where we will handle it later. */
5764 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5765 emit_jump_insn ((*gen_bgt_pat) (label_rtx (test_label)));
5768 /* Value belongs to this node or to the left-hand subtree. */
5770 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5771 GE, NULL_RTX, mode, unsignedp, 0);
5772 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5774 /* Handle the left-hand subtree. */
5775 emit_case_nodes (index, node->left, default_label, index_type);
5777 /* If right node had to be handled later, do that now. */
5781 /* If the left-hand subtree fell through,
5782 don't let it fall into the right-hand subtree. */
5783 emit_jump_if_reachable (default_label);
5785 expand_label (test_label);
5786 emit_case_nodes (index, node->right, default_label, index_type);
5790 else if (node->right != 0 && node->left == 0)
5792 /* Deal with values to the left of this node,
5793 if they are possible. */
5794 if (!node_has_low_bound (node, index_type))
5796 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5798 LT, NULL_RTX, mode, unsignedp, 0);
5799 emit_jump_insn ((*gen_blt_pat) (default_label));
5802 /* Value belongs to this node or to the right-hand subtree. */
5804 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5806 LE, NULL_RTX, mode, unsignedp, 0);
5807 emit_jump_insn ((*gen_ble_pat) (label_rtx (node->code_label)));
5809 emit_case_nodes (index, node->right, default_label, index_type);
5812 else if (node->right == 0 && node->left != 0)
5814 /* Deal with values to the right of this node,
5815 if they are possible. */
5816 if (!node_has_high_bound (node, index_type))
5818 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5820 GT, NULL_RTX, mode, unsignedp, 0);
5821 emit_jump_insn ((*gen_bgt_pat) (default_label));
5824 /* Value belongs to this node or to the left-hand subtree. */
5826 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5827 GE, NULL_RTX, mode, unsignedp, 0);
5828 emit_jump_insn ((*gen_bge_pat) (label_rtx (node->code_label)));
5830 emit_case_nodes (index, node->left, default_label, index_type);
5835 /* Node has no children so we check low and high bounds to remove
5836 redundant tests. Only one of the bounds can exist,
5837 since otherwise this node is bounded--a case tested already. */
5839 if (!node_has_high_bound (node, index_type))
5841 emit_cmp_insn (index, expand_expr (node->high, NULL_RTX,
5843 GT, NULL_RTX, mode, unsignedp, 0);
5844 emit_jump_insn ((*gen_bgt_pat) (default_label));
5847 if (!node_has_low_bound (node, index_type))
5849 emit_cmp_insn (index, expand_expr (node->low, NULL_RTX,
5851 LT, NULL_RTX, mode, unsignedp, 0);
5852 emit_jump_insn ((*gen_blt_pat) (default_label));
5855 emit_jump (label_rtx (node->code_label));
5860 /* These routines are used by the loop unrolling code. They copy BLOCK trees
5861 so that the debugging info will be correct for the unrolled loop. */
5863 /* Indexed by block number, contains a pointer to the N'th block node. */
5865 static tree *block_vector;
5868 find_loop_tree_blocks ()
5870 tree block = DECL_INITIAL (current_function_decl);
5872 block_vector = identify_blocks (block, get_insns ());
5876 unroll_block_trees ()
5878 tree block = DECL_INITIAL (current_function_decl);
5880 reorder_blocks (block_vector, block, get_insns ());