1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-98, 1999 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. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
56 #define obstack_chunk_alloc xmalloc
57 #define obstack_chunk_free free
58 struct obstack stmt_obstack;
60 /* Assume that case vectors are not pc-relative. */
61 #ifndef CASE_VECTOR_PC_RELATIVE
62 #define CASE_VECTOR_PC_RELATIVE 0
65 /* Filename and line number of last line-number note,
66 whether we actually emitted it or not. */
70 /* Nonzero if within a ({...}) grouping, in which case we must
71 always compute a value for each expr-stmt in case it is the last one. */
73 int expr_stmts_for_value;
75 /* Each time we expand an expression-statement,
76 record the expr's type and its RTL value here. */
78 static tree last_expr_type;
79 static rtx last_expr_value;
81 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
82 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
83 This is used by the `remember_end_note' function to record the endpoint
84 of each generated block in its associated BLOCK node. */
86 static rtx last_block_end_note;
88 /* Number of binding contours started so far in this function. */
90 int block_start_count;
92 /* Nonzero if function being compiled needs to
93 return the address of where it has put a structure value. */
95 extern int current_function_returns_pcc_struct;
97 /* Label that will go on parm cleanup code, if any.
98 Jumping to this label runs cleanup code for parameters, if
99 such code must be run. Following this code is the logical return label. */
101 extern rtx cleanup_label;
103 /* Label that will go on function epilogue.
104 Jumping to this label serves as a "return" instruction
105 on machines which require execution of the epilogue on all returns. */
107 extern rtx return_label;
109 /* Offset to end of allocated area of stack frame.
110 If stack grows down, this is the address of the last stack slot allocated.
111 If stack grows up, this is the address for the next slot. */
112 extern int frame_offset;
114 /* Label to jump back to for tail recursion, or 0 if we have
115 not yet needed one for this function. */
116 extern rtx tail_recursion_label;
118 /* Place after which to insert the tail_recursion_label if we need one. */
119 extern rtx tail_recursion_reentry;
121 /* Location at which to save the argument pointer if it will need to be
122 referenced. There are two cases where this is done: if nonlocal gotos
123 exist, or if vars whose is an offset from the argument pointer will be
124 needed by inner routines. */
126 extern rtx arg_pointer_save_area;
128 /* Chain of all RTL_EXPRs that have insns in them. */
129 extern tree rtl_expr_chain;
131 /* Functions and data structures for expanding case statements. */
133 /* Case label structure, used to hold info on labels within case
134 statements. We handle "range" labels; for a single-value label
135 as in C, the high and low limits are the same.
137 An AVL tree of case nodes is initially created, and later transformed
138 to a list linked via the RIGHT fields in the nodes. Nodes with
139 higher case values are later in the list.
141 Switch statements can be output in one of two forms. A branch table
142 is used if there are more than a few labels and the labels are dense
143 within the range between the smallest and largest case value. If a
144 branch table is used, no further manipulations are done with the case
147 The alternative to the use of a branch table is to generate a series
148 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
149 and PARENT fields to hold a binary tree. Initially the tree is
150 totally unbalanced, with everything on the right. We balance the tree
151 with nodes on the left having lower case values than the parent
152 and nodes on the right having higher values. We then output the tree
157 struct case_node *left; /* Left son in binary tree */
158 struct case_node *right; /* Right son in binary tree; also node chain */
159 struct case_node *parent; /* Parent of node in binary tree */
160 tree low; /* Lowest index value for this label */
161 tree high; /* Highest index value for this label */
162 tree code_label; /* Label to jump to when node matches */
166 typedef struct case_node case_node;
167 typedef struct case_node *case_node_ptr;
169 /* These are used by estimate_case_costs and balance_case_nodes. */
171 /* This must be a signed type, and non-ANSI compilers lack signed char. */
172 static short *cost_table;
173 static int use_cost_table;
175 /* Stack of control and binding constructs we are currently inside.
177 These constructs begin when you call `expand_start_WHATEVER'
178 and end when you call `expand_end_WHATEVER'. This stack records
179 info about how the construct began that tells the end-function
180 what to do. It also may provide information about the construct
181 to alter the behavior of other constructs within the body.
182 For example, they may affect the behavior of C `break' and `continue'.
184 Each construct gets one `struct nesting' object.
185 All of these objects are chained through the `all' field.
186 `nesting_stack' points to the first object (innermost construct).
187 The position of an entry on `nesting_stack' is in its `depth' field.
189 Each type of construct has its own individual stack.
190 For example, loops have `loop_stack'. Each object points to the
191 next object of the same type through the `next' field.
193 Some constructs are visible to `break' exit-statements and others
194 are not. Which constructs are visible depends on the language.
195 Therefore, the data structure allows each construct to be visible
196 or not, according to the args given when the construct is started.
197 The construct is visible if the `exit_label' field is non-null.
198 In that case, the value should be a CODE_LABEL rtx. */
203 struct nesting *next;
208 /* For conds (if-then and if-then-else statements). */
211 /* Label for the end of the if construct.
212 There is none if EXITFLAG was not set
213 and no `else' has been seen yet. */
215 /* Label for the end of this alternative.
216 This may be the end of the if or the next else/elseif. */
222 /* Label at the top of the loop; place to loop back to. */
224 /* Label at the end of the whole construct. */
226 /* Label before a jump that branches to the end of the whole
227 construct. This is where destructors go if any. */
229 /* Label for `continue' statement to jump to;
230 this is in front of the stepper of the loop. */
233 /* For variable binding contours. */
236 /* Sequence number of this binding contour within the function,
237 in order of entry. */
238 int block_start_count;
239 /* Nonzero => value to restore stack to on exit. */
241 /* The NOTE that starts this contour.
242 Used by expand_goto to check whether the destination
243 is within each contour or not. */
245 /* Innermost containing binding contour that has a stack level. */
246 struct nesting *innermost_stack_block;
247 /* List of cleanups to be run on exit from this contour.
248 This is a list of expressions to be evaluated.
249 The TREE_PURPOSE of each link is the ..._DECL node
250 which the cleanup pertains to. */
252 /* List of cleanup-lists of blocks containing this block,
253 as they were at the locus where this block appears.
254 There is an element for each containing block,
255 ordered innermost containing block first.
256 The tail of this list can be 0,
257 if all remaining elements would be empty lists.
258 The element's TREE_VALUE is the cleanup-list of that block,
259 which may be null. */
261 /* Chain of labels defined inside this binding contour.
262 For contours that have stack levels or cleanups. */
263 struct label_chain *label_chain;
264 /* Number of function calls seen, as of start of this block. */
265 int function_call_count;
266 /* Nonzero if this is associated with a EH region. */
267 int exception_region;
268 /* The saved target_temp_slot_level from our outer block.
269 We may reset target_temp_slot_level to be the level of
270 this block, if that is done, target_temp_slot_level
271 reverts to the saved target_temp_slot_level at the very
273 int target_temp_slot_level;
274 /* True if we are currently emitting insns in an area of
275 output code that is controlled by a conditional
276 expression. This is used by the cleanup handling code to
277 generate conditional cleanup actions. */
278 int conditional_code;
279 /* A place to move the start of the exception region for any
280 of the conditional cleanups, must be at the end or after
281 the start of the last unconditional cleanup, and before any
282 conditional branch points. */
283 rtx last_unconditional_cleanup;
284 /* When in a conditional context, this is the specific
285 cleanup list associated with last_unconditional_cleanup,
286 where we place the conditionalized cleanups. */
289 /* For switch (C) or case (Pascal) statements,
290 and also for dummies (see `expand_start_case_dummy'). */
293 /* The insn after which the case dispatch should finally
294 be emitted. Zero for a dummy. */
296 /* A list of case labels; it is first built as an AVL tree.
297 During expand_end_case, this is converted to a list, and may be
298 rearranged into a nearly balanced binary tree. */
299 struct case_node *case_list;
300 /* Label to jump to if no case matches. */
302 /* The expression to be dispatched on. */
304 /* Type that INDEX_EXPR should be converted to. */
306 /* Number of range exprs in case statement. */
308 /* Name of this kind of statement, for warnings. */
310 /* Used to save no_line_numbers till we see the first case label.
311 We set this to -1 when we see the first case label in this
313 int line_number_status;
318 /* Chain of all pending binding contours. */
319 struct nesting *block_stack;
321 /* If any new stacks are added here, add them to POPSTACKS too. */
323 /* Chain of all pending binding contours that restore stack levels
325 struct nesting *stack_block_stack;
327 /* Chain of all pending conditional statements. */
328 struct nesting *cond_stack;
330 /* Chain of all pending loops. */
331 struct nesting *loop_stack;
333 /* Chain of all pending case or switch statements. */
334 struct nesting *case_stack;
336 /* Separate chain including all of the above,
337 chained through the `all' field. */
338 struct nesting *nesting_stack;
340 /* Number of entries on nesting_stack now. */
343 /* Allocate and return a new `struct nesting'. */
345 #define ALLOC_NESTING() \
346 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
348 /* Pop the nesting stack element by element until we pop off
349 the element which is at the top of STACK.
350 Update all the other stacks, popping off elements from them
351 as we pop them from nesting_stack. */
353 #define POPSTACK(STACK) \
354 do { struct nesting *target = STACK; \
355 struct nesting *this; \
356 do { this = nesting_stack; \
357 if (loop_stack == this) \
358 loop_stack = loop_stack->next; \
359 if (cond_stack == this) \
360 cond_stack = cond_stack->next; \
361 if (block_stack == this) \
362 block_stack = block_stack->next; \
363 if (stack_block_stack == this) \
364 stack_block_stack = stack_block_stack->next; \
365 if (case_stack == this) \
366 case_stack = case_stack->next; \
367 nesting_depth = nesting_stack->depth - 1; \
368 nesting_stack = this->all; \
369 obstack_free (&stmt_obstack, this); } \
370 while (this != target); } while (0)
372 /* In some cases it is impossible to generate code for a forward goto
373 until the label definition is seen. This happens when it may be necessary
374 for the goto to reset the stack pointer: we don't yet know how to do that.
375 So expand_goto puts an entry on this fixup list.
376 Each time a binding contour that resets the stack is exited,
378 If the target label has now been defined, we can insert the proper code. */
382 /* Points to following fixup. */
383 struct goto_fixup *next;
384 /* Points to the insn before the jump insn.
385 If more code must be inserted, it goes after this insn. */
387 /* The LABEL_DECL that this jump is jumping to, or 0
388 for break, continue or return. */
390 /* The BLOCK for the place where this goto was found. */
392 /* The CODE_LABEL rtx that this is jumping to. */
394 /* Number of binding contours started in current function
395 before the label reference. */
396 int block_start_count;
397 /* The outermost stack level that should be restored for this jump.
398 Each time a binding contour that resets the stack is exited,
399 if the target label is *not* yet defined, this slot is updated. */
401 /* List of lists of cleanup expressions to be run by this goto.
402 There is one element for each block that this goto is within.
403 The tail of this list can be 0,
404 if all remaining elements would be empty.
405 The TREE_VALUE contains the cleanup list of that block as of the
406 time this goto was seen.
407 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
408 tree cleanup_list_list;
411 static struct goto_fixup *goto_fixup_chain;
413 /* Within any binding contour that must restore a stack level,
414 all labels are recorded with a chain of these structures. */
418 /* Points to following fixup. */
419 struct label_chain *next;
424 /* Non-zero if we are using EH to handle cleanus. */
425 static int using_eh_for_cleanups_p = 0;
428 static int n_occurrences PROTO((int, char *));
429 static void expand_goto_internal PROTO((tree, rtx, rtx));
430 static int expand_fixup PROTO((tree, rtx, rtx));
431 static void expand_nl_handler_label PROTO((rtx, rtx));
432 static void expand_nl_goto_receiver PROTO((void));
433 static void expand_nl_goto_receivers PROTO((struct nesting *));
434 static void fixup_gotos PROTO((struct nesting *, rtx, tree,
436 static void expand_null_return_1 PROTO((rtx, int));
437 static void expand_value_return PROTO((rtx));
438 static int tail_recursion_args PROTO((tree, tree));
439 static void expand_cleanups PROTO((tree, tree, int, int));
440 static void check_seenlabel PROTO((void));
441 static void do_jump_if_equal PROTO((rtx, rtx, rtx, int));
442 static int estimate_case_costs PROTO((case_node_ptr));
443 static void group_case_nodes PROTO((case_node_ptr));
444 static void balance_case_nodes PROTO((case_node_ptr *,
446 static int node_has_low_bound PROTO((case_node_ptr, tree));
447 static int node_has_high_bound PROTO((case_node_ptr, tree));
448 static int node_is_bounded PROTO((case_node_ptr, tree));
449 static void emit_jump_if_reachable PROTO((rtx));
450 static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree));
451 static int add_case_node PROTO((tree, tree, tree, tree *));
452 static struct case_node *case_tree2list PROTO((case_node *, case_node *));
455 using_eh_for_cleanups ()
457 using_eh_for_cleanups_p = 1;
463 gcc_obstack_init (&stmt_obstack);
468 init_stmt_for_function ()
470 /* We are not currently within any block, conditional, loop or case. */
472 stack_block_stack = 0;
479 block_start_count = 0;
481 /* No gotos have been expanded yet. */
482 goto_fixup_chain = 0;
484 /* We are not processing a ({...}) grouping. */
485 expr_stmts_for_value = 0;
488 init_eh_for_function ();
495 p->block_stack = block_stack;
496 p->stack_block_stack = stack_block_stack;
497 p->cond_stack = cond_stack;
498 p->loop_stack = loop_stack;
499 p->case_stack = case_stack;
500 p->nesting_stack = nesting_stack;
501 p->nesting_depth = nesting_depth;
502 p->block_start_count = block_start_count;
503 p->last_expr_type = last_expr_type;
504 p->last_expr_value = last_expr_value;
505 p->expr_stmts_for_value = expr_stmts_for_value;
506 p->emit_filename = emit_filename;
507 p->emit_lineno = emit_lineno;
508 p->goto_fixup_chain = goto_fixup_chain;
513 restore_stmt_status (p)
516 block_stack = p->block_stack;
517 stack_block_stack = p->stack_block_stack;
518 cond_stack = p->cond_stack;
519 loop_stack = p->loop_stack;
520 case_stack = p->case_stack;
521 nesting_stack = p->nesting_stack;
522 nesting_depth = p->nesting_depth;
523 block_start_count = p->block_start_count;
524 last_expr_type = p->last_expr_type;
525 last_expr_value = p->last_expr_value;
526 expr_stmts_for_value = p->expr_stmts_for_value;
527 emit_filename = p->emit_filename;
528 emit_lineno = p->emit_lineno;
529 goto_fixup_chain = p->goto_fixup_chain;
530 restore_eh_status (p);
533 /* Emit a no-op instruction. */
540 last_insn = get_last_insn ();
542 && (GET_CODE (last_insn) == CODE_LABEL
543 || (GET_CODE (last_insn) == NOTE
544 && prev_real_insn (last_insn) == 0)))
545 emit_insn (gen_nop ());
548 /* Return the rtx-label that corresponds to a LABEL_DECL,
549 creating it if necessary. */
555 if (TREE_CODE (label) != LABEL_DECL)
558 if (DECL_RTL (label))
559 return DECL_RTL (label);
561 return DECL_RTL (label) = gen_label_rtx ();
564 /* Add an unconditional jump to LABEL as the next sequential instruction. */
570 do_pending_stack_adjust ();
571 emit_jump_insn (gen_jump (label));
575 /* Emit code to jump to the address
576 specified by the pointer expression EXP. */
579 expand_computed_goto (exp)
582 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
584 #ifdef POINTERS_EXTEND_UNSIGNED
585 x = convert_memory_address (Pmode, x);
589 /* Be sure the function is executable. */
590 if (current_function_check_memory_usage)
591 emit_library_call (chkr_check_exec_libfunc, 1,
592 VOIDmode, 1, x, ptr_mode);
594 do_pending_stack_adjust ();
595 emit_indirect_jump (x);
597 current_function_has_computed_jump = 1;
600 /* Handle goto statements and the labels that they can go to. */
602 /* Specify the location in the RTL code of a label LABEL,
603 which is a LABEL_DECL tree node.
605 This is used for the kind of label that the user can jump to with a
606 goto statement, and for alternatives of a switch or case statement.
607 RTL labels generated for loops and conditionals don't go through here;
608 they are generated directly at the RTL level, by other functions below.
610 Note that this has nothing to do with defining label *names*.
611 Languages vary in how they do that and what that even means. */
617 struct label_chain *p;
619 do_pending_stack_adjust ();
620 emit_label (label_rtx (label));
621 if (DECL_NAME (label))
622 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
624 if (stack_block_stack != 0)
626 p = (struct label_chain *) oballoc (sizeof (struct label_chain));
627 p->next = stack_block_stack->data.block.label_chain;
628 stack_block_stack->data.block.label_chain = p;
633 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
634 from nested functions. */
637 declare_nonlocal_label (label)
640 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
642 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
643 LABEL_PRESERVE_P (label_rtx (label)) = 1;
644 if (nonlocal_goto_handler_slots == 0)
646 emit_stack_save (SAVE_NONLOCAL,
647 &nonlocal_goto_stack_level,
648 PREV_INSN (tail_recursion_reentry));
650 nonlocal_goto_handler_slots
651 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
654 /* Generate RTL code for a `goto' statement with target label LABEL.
655 LABEL should be a LABEL_DECL tree node that was or will later be
656 defined with `expand_label'. */
664 /* Check for a nonlocal goto to a containing function. */
665 context = decl_function_context (label);
666 if (context != 0 && context != current_function_decl)
668 struct function *p = find_function_data (context);
669 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
670 rtx temp, handler_slot;
673 /* Find the corresponding handler slot for this label. */
674 handler_slot = p->nonlocal_goto_handler_slots;
675 for (link = p->nonlocal_labels; TREE_VALUE (link) != label;
676 link = TREE_CHAIN (link))
677 handler_slot = XEXP (handler_slot, 1);
678 handler_slot = XEXP (handler_slot, 0);
680 p->has_nonlocal_label = 1;
681 current_function_has_nonlocal_goto = 1;
682 LABEL_REF_NONLOCAL_P (label_ref) = 1;
684 /* Copy the rtl for the slots so that they won't be shared in
685 case the virtual stack vars register gets instantiated differently
686 in the parent than in the child. */
688 #if HAVE_nonlocal_goto
689 if (HAVE_nonlocal_goto)
690 emit_insn (gen_nonlocal_goto (lookup_static_chain (label),
691 copy_rtx (handler_slot),
692 copy_rtx (p->nonlocal_goto_stack_level),
699 /* Restore frame pointer for containing function.
700 This sets the actual hard register used for the frame pointer
701 to the location of the function's incoming static chain info.
702 The non-local goto handler will then adjust it to contain the
703 proper value and reload the argument pointer, if needed. */
704 emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label));
706 /* We have now loaded the frame pointer hardware register with
707 the address of that corresponds to the start of the virtual
708 stack vars. So replace virtual_stack_vars_rtx in all
709 addresses we use with stack_pointer_rtx. */
711 /* Get addr of containing function's current nonlocal goto handler,
712 which will do any cleanups and then jump to the label. */
713 addr = copy_rtx (handler_slot);
714 temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx,
715 hard_frame_pointer_rtx));
717 /* Restore the stack pointer. Note this uses fp just restored. */
718 addr = p->nonlocal_goto_stack_level;
720 addr = replace_rtx (copy_rtx (addr),
721 virtual_stack_vars_rtx,
722 hard_frame_pointer_rtx);
724 emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX);
726 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
728 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
729 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
730 emit_indirect_jump (temp);
734 expand_goto_internal (label, label_rtx (label), NULL_RTX);
737 /* Generate RTL code for a `goto' statement with target label BODY.
738 LABEL should be a LABEL_REF.
739 LAST_INSN, if non-0, is the rtx we should consider as the last
740 insn emitted (for the purposes of cleaning up a return). */
743 expand_goto_internal (body, label, last_insn)
748 struct nesting *block;
751 if (GET_CODE (label) != CODE_LABEL)
754 /* If label has already been defined, we can tell now
755 whether and how we must alter the stack level. */
757 if (PREV_INSN (label) != 0)
759 /* Find the innermost pending block that contains the label.
760 (Check containment by comparing insn-uids.)
761 Then restore the outermost stack level within that block,
762 and do cleanups of all blocks contained in it. */
763 for (block = block_stack; block; block = block->next)
765 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
767 if (block->data.block.stack_level != 0)
768 stack_level = block->data.block.stack_level;
769 /* Execute the cleanups for blocks we are exiting. */
770 if (block->data.block.cleanups != 0)
772 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
773 do_pending_stack_adjust ();
779 /* Ensure stack adjust isn't done by emit_jump, as this
780 would clobber the stack pointer. This one should be
781 deleted as dead by flow. */
782 clear_pending_stack_adjust ();
783 do_pending_stack_adjust ();
784 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
787 if (body != 0 && DECL_TOO_LATE (body))
788 error ("jump to `%s' invalidly jumps into binding contour",
789 IDENTIFIER_POINTER (DECL_NAME (body)));
791 /* Label not yet defined: may need to put this goto
792 on the fixup list. */
793 else if (! expand_fixup (body, label, last_insn))
795 /* No fixup needed. Record that the label is the target
796 of at least one goto that has no fixup. */
798 TREE_ADDRESSABLE (body) = 1;
804 /* Generate if necessary a fixup for a goto
805 whose target label in tree structure (if any) is TREE_LABEL
806 and whose target in rtl is RTL_LABEL.
808 If LAST_INSN is nonzero, we pretend that the jump appears
809 after insn LAST_INSN instead of at the current point in the insn stream.
811 The fixup will be used later to insert insns just before the goto.
812 Those insns will restore the stack level as appropriate for the
813 target label, and will (in the case of C++) also invoke any object
814 destructors which have to be invoked when we exit the scopes which
815 are exited by the goto.
817 Value is nonzero if a fixup is made. */
820 expand_fixup (tree_label, rtl_label, last_insn)
825 struct nesting *block, *end_block;
827 /* See if we can recognize which block the label will be output in.
828 This is possible in some very common cases.
829 If we succeed, set END_BLOCK to that block.
830 Otherwise, set it to 0. */
833 && (rtl_label == cond_stack->data.cond.endif_label
834 || rtl_label == cond_stack->data.cond.next_label))
835 end_block = cond_stack;
836 /* If we are in a loop, recognize certain labels which
837 are likely targets. This reduces the number of fixups
838 we need to create. */
840 && (rtl_label == loop_stack->data.loop.start_label
841 || rtl_label == loop_stack->data.loop.end_label
842 || rtl_label == loop_stack->data.loop.continue_label))
843 end_block = loop_stack;
847 /* Now set END_BLOCK to the binding level to which we will return. */
851 struct nesting *next_block = end_block->all;
854 /* First see if the END_BLOCK is inside the innermost binding level.
855 If so, then no cleanups or stack levels are relevant. */
856 while (next_block && next_block != block)
857 next_block = next_block->all;
862 /* Otherwise, set END_BLOCK to the innermost binding level
863 which is outside the relevant control-structure nesting. */
864 next_block = block_stack->next;
865 for (block = block_stack; block != end_block; block = block->all)
866 if (block == next_block)
867 next_block = next_block->next;
868 end_block = next_block;
871 /* Does any containing block have a stack level or cleanups?
872 If not, no fixup is needed, and that is the normal case
873 (the only case, for standard C). */
874 for (block = block_stack; block != end_block; block = block->next)
875 if (block->data.block.stack_level != 0
876 || block->data.block.cleanups != 0)
879 if (block != end_block)
881 /* Ok, a fixup is needed. Add a fixup to the list of such. */
882 struct goto_fixup *fixup
883 = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup));
884 /* In case an old stack level is restored, make sure that comes
885 after any pending stack adjust. */
886 /* ?? If the fixup isn't to come at the present position,
887 doing the stack adjust here isn't useful. Doing it with our
888 settings at that location isn't useful either. Let's hope
891 do_pending_stack_adjust ();
892 fixup->target = tree_label;
893 fixup->target_rtl = rtl_label;
895 /* Create a BLOCK node and a corresponding matched set of
896 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
897 this point. The notes will encapsulate any and all fixup
898 code which we might later insert at this point in the insn
899 stream. Also, the BLOCK node will be the parent (i.e. the
900 `SUPERBLOCK') of any other BLOCK nodes which we might create
901 later on when we are expanding the fixup code.
903 Note that optimization passes (including expand_end_loop)
904 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
908 register rtx original_before_jump
909 = last_insn ? last_insn : get_last_insn ();
914 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
915 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
916 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
917 fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */
919 emit_insns_after (start, original_before_jump);
922 fixup->block_start_count = block_start_count;
923 fixup->stack_level = 0;
924 fixup->cleanup_list_list
925 = ((block->data.block.outer_cleanups
926 || block->data.block.cleanups)
927 ? tree_cons (NULL_TREE, block->data.block.cleanups,
928 block->data.block.outer_cleanups)
930 fixup->next = goto_fixup_chain;
931 goto_fixup_chain = fixup;
939 /* Expand any needed fixups in the outputmost binding level of the
940 function. FIRST_INSN is the first insn in the function. */
943 expand_fixups (first_insn)
946 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
949 /* When exiting a binding contour, process all pending gotos requiring fixups.
950 THISBLOCK is the structure that describes the block being exited.
951 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
952 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
953 FIRST_INSN is the insn that began this contour.
955 Gotos that jump out of this contour must restore the
956 stack level and do the cleanups before actually jumping.
958 DONT_JUMP_IN nonzero means report error there is a jump into this
959 contour from before the beginning of the contour.
960 This is also done if STACK_LEVEL is nonzero. */
963 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
964 struct nesting *thisblock;
970 register struct goto_fixup *f, *prev;
972 /* F is the fixup we are considering; PREV is the previous one. */
973 /* We run this loop in two passes so that cleanups of exited blocks
974 are run first, and blocks that are exited are marked so
977 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
979 /* Test for a fixup that is inactive because it is already handled. */
980 if (f->before_jump == 0)
982 /* Delete inactive fixup from the chain, if that is easy to do. */
984 prev->next = f->next;
986 /* Has this fixup's target label been defined?
987 If so, we can finalize it. */
988 else if (PREV_INSN (f->target_rtl) != 0)
990 register rtx cleanup_insns;
992 /* Get the first non-label after the label
993 this goto jumps to. If that's before this scope begins,
994 we don't have a jump into the scope. */
995 rtx after_label = f->target_rtl;
996 while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL)
997 after_label = NEXT_INSN (after_label);
999 /* If this fixup jumped into this contour from before the beginning
1000 of this contour, report an error. */
1001 /* ??? Bug: this does not detect jumping in through intermediate
1002 blocks that have stack levels or cleanups.
1003 It detects only a problem with the innermost block
1004 around the label. */
1006 && (dont_jump_in || stack_level || cleanup_list)
1007 /* If AFTER_LABEL is 0, it means the jump goes to the end
1008 of the rtl, which means it jumps into this scope. */
1009 && (after_label == 0
1010 || INSN_UID (first_insn) < INSN_UID (after_label))
1011 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1012 && ! DECL_ERROR_ISSUED (f->target))
1014 error_with_decl (f->target,
1015 "label `%s' used before containing binding contour");
1016 /* Prevent multiple errors for one label. */
1017 DECL_ERROR_ISSUED (f->target) = 1;
1020 /* We will expand the cleanups into a sequence of their own and
1021 then later on we will attach this new sequence to the insn
1022 stream just ahead of the actual jump insn. */
1026 /* Temporarily restore the lexical context where we will
1027 logically be inserting the fixup code. We do this for the
1028 sake of getting the debugging information right. */
1031 set_block (f->context);
1033 /* Expand the cleanups for blocks this jump exits. */
1034 if (f->cleanup_list_list)
1037 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1038 /* Marked elements correspond to blocks that have been closed.
1039 Do their cleanups. */
1040 if (TREE_ADDRESSABLE (lists)
1041 && TREE_VALUE (lists) != 0)
1043 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1044 /* Pop any pushes done in the cleanups,
1045 in case function is about to return. */
1046 do_pending_stack_adjust ();
1050 /* Restore stack level for the biggest contour that this
1051 jump jumps out of. */
1053 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1055 /* Finish up the sequence containing the insns which implement the
1056 necessary cleanups, and then attach that whole sequence to the
1057 insn stream just ahead of the actual jump insn. Attaching it
1058 at that point insures that any cleanups which are in fact
1059 implicit C++ object destructions (which must be executed upon
1060 leaving the block) appear (to the debugger) to be taking place
1061 in an area of the generated code where the object(s) being
1062 destructed are still "in scope". */
1064 cleanup_insns = get_insns ();
1068 emit_insns_after (cleanup_insns, f->before_jump);
1075 /* For any still-undefined labels, do the cleanups for this block now.
1076 We must do this now since items in the cleanup list may go out
1077 of scope when the block ends. */
1078 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1079 if (f->before_jump != 0
1080 && PREV_INSN (f->target_rtl) == 0
1081 /* Label has still not appeared. If we are exiting a block with
1082 a stack level to restore, that started before the fixup,
1083 mark this stack level as needing restoration
1084 when the fixup is later finalized. */
1086 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1087 means the label is undefined. That's erroneous, but possible. */
1088 && (thisblock->data.block.block_start_count
1089 <= f->block_start_count))
1091 tree lists = f->cleanup_list_list;
1094 for (; lists; lists = TREE_CHAIN (lists))
1095 /* If the following elt. corresponds to our containing block
1096 then the elt. must be for this block. */
1097 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1101 set_block (f->context);
1102 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1103 do_pending_stack_adjust ();
1104 cleanup_insns = get_insns ();
1107 if (cleanup_insns != 0)
1109 = emit_insns_after (cleanup_insns, f->before_jump);
1111 f->cleanup_list_list = TREE_CHAIN (lists);
1115 f->stack_level = stack_level;
1119 /* Return the number of times character C occurs in string S. */
1121 n_occurrences (c, s)
1131 /* Generate RTL for an asm statement (explicit assembler code).
1132 BODY is a STRING_CST node containing the assembler code text,
1133 or an ADDR_EXPR containing a STRING_CST. */
1139 if (current_function_check_memory_usage)
1141 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1145 if (TREE_CODE (body) == ADDR_EXPR)
1146 body = TREE_OPERAND (body, 0);
1148 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1149 TREE_STRING_POINTER (body)));
1153 /* Generate RTL for an asm statement with arguments.
1154 STRING is the instruction template.
1155 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1156 Each output or input has an expression in the TREE_VALUE and
1157 a constraint-string in the TREE_PURPOSE.
1158 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1159 that is clobbered by this insn.
1161 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1162 Some elements of OUTPUTS may be replaced with trees representing temporary
1163 values. The caller should copy those temporary values to the originally
1166 VOL nonzero means the insn is volatile; don't optimize it. */
1169 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1170 tree string, outputs, inputs, clobbers;
1175 rtvec argvec, constraints;
1177 int ninputs = list_length (inputs);
1178 int noutputs = list_length (outputs);
1183 /* Vector of RTX's of evaluated output operands. */
1184 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1185 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1186 enum machine_mode *inout_mode
1187 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1188 /* The insn we have emitted. */
1191 /* An ASM with no outputs needs to be treated as volatile, for now. */
1195 if (current_function_check_memory_usage)
1197 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1201 /* Count the number of meaningful clobbered registers, ignoring what
1202 we would ignore later. */
1204 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1206 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1207 i = decode_reg_name (regname);
1208 if (i >= 0 || i == -4)
1211 error ("unknown register name `%s' in `asm'", regname);
1216 /* Check that the number of alternatives is constant across all
1218 if (outputs || inputs)
1220 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1221 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1224 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1226 error ("too many alternatives in `asm'");
1233 char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1234 if (n_occurrences (',', constraint) != nalternatives)
1236 error ("operand constraints for `asm' differ in number of alternatives");
1239 if (TREE_CHAIN (tmp))
1240 tmp = TREE_CHAIN (tmp);
1242 tmp = next, next = 0;
1246 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1248 tree val = TREE_VALUE (tail);
1249 tree type = TREE_TYPE (val);
1258 /* If there's an erroneous arg, emit no insn. */
1259 if (TREE_TYPE (val) == error_mark_node)
1262 /* Make sure constraint has `=' and does not have `+'. Also, see
1263 if it allows any register. Be liberal on the latter test, since
1264 the worst that happens if we get it wrong is we issue an error
1267 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1268 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1270 /* Allow the `=' or `+' to not be at the beginning of the string,
1271 since it wasn't explicitly documented that way, and there is a
1272 large body of code that puts it last. Swap the character to
1273 the front, so as not to uglify any place else. */
1277 if ((p = strchr (constraint, '=')) != NULL)
1279 if ((p = strchr (constraint, '+')) != NULL)
1282 error ("output operand constraint lacks `='");
1286 if (p != constraint)
1289 bcopy (constraint, constraint+1, p-constraint);
1292 warning ("output constraint `%c' for operand %d is not at the beginning", j, i);
1295 is_inout = constraint[0] == '+';
1296 /* Replace '+' with '='. */
1297 constraint[0] = '=';
1298 /* Make sure we can specify the matching operand. */
1299 if (is_inout && i > 9)
1301 error ("output operand constraint %d contains `+'", i);
1305 for (j = 1; j < c_len; j++)
1306 switch (constraint[j])
1310 error ("operand constraint contains '+' or '=' at illegal position.");
1314 if (i + 1 == ninputs + noutputs)
1316 error ("`%%' constraint used with last operand");
1321 case '?': case '!': case '*': case '&':
1322 case 'E': case 'F': case 'G': case 'H':
1323 case 's': case 'i': case 'n':
1324 case 'I': case 'J': case 'K': case 'L': case 'M':
1325 case 'N': case 'O': case 'P': case ',':
1326 #ifdef EXTRA_CONSTRAINT
1327 case 'Q': case 'R': case 'S': case 'T': case 'U':
1331 case '0': case '1': case '2': case '3': case '4':
1332 case '5': case '6': case '7': case '8': case '9':
1333 error ("matching constraint not valid in output operand");
1336 case 'V': case 'm': case 'o':
1341 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1342 excepting those that expand_call created. So match memory
1358 /* If an output operand is not a decl or indirect ref and our constraint
1359 allows a register, make a temporary to act as an intermediate.
1360 Make the asm insn write into that, then our caller will copy it to
1361 the real output operand. Likewise for promoted variables. */
1363 if ((TREE_CODE (val) == INDIRECT_REF
1365 || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd'
1366 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1367 && ! (GET_CODE (DECL_RTL (val)) == REG
1368 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1373 mark_addressable (TREE_VALUE (tail));
1376 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1377 EXPAND_MEMORY_USE_WO);
1379 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1380 error ("output number %d not directly addressable", i);
1381 if (! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1382 error ("output number %d not restored to memory", i);
1386 output_rtx[i] = assign_temp (type, 0, 0, 0);
1387 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1392 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1393 inout_opnum[ninout++] = i;
1398 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1400 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1404 /* Make vectors for the expression-rtx and constraint strings. */
1406 argvec = rtvec_alloc (ninputs);
1407 constraints = rtvec_alloc (ninputs);
1409 body = gen_rtx_ASM_OPERANDS (VOIDmode,
1410 TREE_STRING_POINTER (string), "", 0, argvec,
1411 constraints, filename, line);
1413 MEM_VOLATILE_P (body) = vol;
1415 /* Eval the inputs and put them into ARGVEC.
1416 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1419 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1422 int allows_reg = 0, allows_mem = 0;
1423 char *constraint, *orig_constraint;
1427 /* If there's an erroneous arg, emit no insn,
1428 because the ASM_INPUT would get VOIDmode
1429 and that could cause a crash in reload. */
1430 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1433 /* ??? Can this happen, and does the error message make any sense? */
1434 if (TREE_PURPOSE (tail) == NULL_TREE)
1436 error ("hard register `%s' listed as input operand to `asm'",
1437 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1441 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1;
1442 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1443 orig_constraint = constraint;
1445 /* Make sure constraint has neither `=', `+', nor '&'. */
1447 for (j = 0; j < c_len; j++)
1448 switch (constraint[j])
1450 case '+': case '=': case '&':
1451 if (constraint == orig_constraint)
1453 error ("input operand constraint contains `%c'", constraint[j]);
1459 if (constraint == orig_constraint
1460 && i + 1 == ninputs - ninout)
1462 error ("`%%' constraint used with last operand");
1467 case 'V': case 'm': case 'o':
1472 case '?': case '!': case '*':
1473 case 'E': case 'F': case 'G': case 'H': case 'X':
1474 case 's': case 'i': case 'n':
1475 case 'I': case 'J': case 'K': case 'L': case 'M':
1476 case 'N': case 'O': case 'P': case ',':
1477 #ifdef EXTRA_CONSTRAINT
1478 case 'Q': case 'R': case 'S': case 'T': case 'U':
1482 /* Whether or not a numeric constraint allows a register is
1483 decided by the matching constraint, and so there is no need
1484 to do anything special with them. We must handle them in
1485 the default case, so that we don't unnecessarily force
1486 operands to memory. */
1487 case '0': case '1': case '2': case '3': case '4':
1488 case '5': case '6': case '7': case '8': case '9':
1489 if (constraint[j] >= '0' + noutputs)
1492 ("matching constraint references invalid operand number");
1496 /* Try and find the real constraint for this dup. */
1497 if ((j == 0 && c_len == 1)
1498 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1501 for (j = constraint[j] - '0'; j > 0; --j)
1504 c_len = TREE_STRING_LENGTH (TREE_PURPOSE (o)) - 1;
1505 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1510 /* ... fall through ... */
1523 if (! allows_reg && allows_mem)
1524 mark_addressable (TREE_VALUE (tail));
1526 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1528 if (asm_operand_ok (op, constraint) <= 0)
1531 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1532 else if (!allows_mem)
1533 warning ("asm operand %d probably doesn't match constraints", i);
1534 else if (CONSTANT_P (op))
1535 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1537 else if (GET_CODE (op) == REG
1538 || GET_CODE (op) == SUBREG
1539 || GET_CODE (op) == CONCAT)
1541 tree type = TREE_TYPE (TREE_VALUE (tail));
1542 rtx memloc = assign_temp (type, 1, 1, 1);
1544 emit_move_insn (memloc, op);
1547 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1548 /* We won't recognize volatile memory as available a
1549 memory_operand at this point. Ignore it. */
1551 else if (queued_subexp_p (op))
1554 /* ??? Leave this only until we have experience with what
1555 happens in combine and elsewhere when constraints are
1557 warning ("asm operand %d probably doesn't match constraints", i);
1559 XVECEXP (body, 3, i) = op;
1561 XVECEXP (body, 4, i) /* constraints */
1562 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1567 /* Protect all the operands from the queue,
1568 now that they have all been evaluated. */
1570 for (i = 0; i < ninputs - ninout; i++)
1571 XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0);
1573 for (i = 0; i < noutputs; i++)
1574 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1576 /* For in-out operands, copy output rtx to input rtx. */
1577 for (i = 0; i < ninout; i++)
1579 static char match[9+1][2]
1580 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1581 int j = inout_opnum[i];
1583 XVECEXP (body, 3, ninputs - ninout + i) /* argvec */
1585 XVECEXP (body, 4, ninputs - ninout + i) /* constraints */
1586 = gen_rtx_ASM_INPUT (inout_mode[j], match[j]);
1589 /* Now, for each output, construct an rtx
1590 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1591 ARGVEC CONSTRAINTS))
1592 If there is more than one, put them inside a PARALLEL. */
1594 if (noutputs == 1 && nclobbers == 0)
1596 XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1597 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1599 else if (noutputs == 0 && nclobbers == 0)
1601 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1602 insn = emit_insn (body);
1608 if (num == 0) num = 1;
1609 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1611 /* For each output operand, store a SET. */
1613 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1615 XVECEXP (body, 0, i)
1616 = gen_rtx_SET (VOIDmode,
1618 gen_rtx_ASM_OPERANDS (VOIDmode,
1619 TREE_STRING_POINTER (string),
1620 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1621 i, argvec, constraints,
1623 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1626 /* If there are no outputs (but there are some clobbers)
1627 store the bare ASM_OPERANDS into the PARALLEL. */
1630 XVECEXP (body, 0, i++) = obody;
1632 /* Store (clobber REG) for each clobbered register specified. */
1634 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1636 char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1637 int j = decode_reg_name (regname);
1641 if (j == -3) /* `cc', which is not a register */
1644 if (j == -4) /* `memory', don't cache memory across asm */
1646 XVECEXP (body, 0, i++)
1647 = gen_rtx_CLOBBER (VOIDmode,
1648 gen_rtx_MEM (BLKmode,
1649 gen_rtx_SCRATCH (VOIDmode)));
1653 /* Ignore unknown register, error already signaled. */
1657 /* Use QImode since that's guaranteed to clobber just one reg. */
1658 XVECEXP (body, 0, i++)
1659 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1662 insn = emit_insn (body);
1668 /* Generate RTL to evaluate the expression EXP
1669 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1672 expand_expr_stmt (exp)
1675 /* If -W, warn about statements with no side effects,
1676 except for an explicit cast to void (e.g. for assert()), and
1677 except inside a ({...}) where they may be useful. */
1678 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1680 if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused)
1681 && !(TREE_CODE (exp) == CONVERT_EXPR
1682 && TREE_TYPE (exp) == void_type_node))
1683 warning_with_file_and_line (emit_filename, emit_lineno,
1684 "statement with no effect");
1685 else if (warn_unused)
1686 warn_if_unused_value (exp);
1689 /* If EXP is of function type and we are expanding statements for
1690 value, convert it to pointer-to-function. */
1691 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1692 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1694 last_expr_type = TREE_TYPE (exp);
1695 last_expr_value = expand_expr (exp,
1696 (expr_stmts_for_value
1697 ? NULL_RTX : const0_rtx),
1700 /* If all we do is reference a volatile value in memory,
1701 copy it to a register to be sure it is actually touched. */
1702 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1703 && TREE_THIS_VOLATILE (exp))
1705 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1707 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1708 copy_to_reg (last_expr_value);
1711 rtx lab = gen_label_rtx ();
1713 /* Compare the value with itself to reference it. */
1714 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1715 expand_expr (TYPE_SIZE (last_expr_type),
1716 NULL_RTX, VOIDmode, 0),
1718 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1724 /* If this expression is part of a ({...}) and is in memory, we may have
1725 to preserve temporaries. */
1726 preserve_temp_slots (last_expr_value);
1728 /* Free any temporaries used to evaluate this expression. Any temporary
1729 used as a result of this expression will already have been preserved
1736 /* Warn if EXP contains any computations whose results are not used.
1737 Return 1 if a warning is printed; 0 otherwise. */
1740 warn_if_unused_value (exp)
1743 if (TREE_USED (exp))
1746 switch (TREE_CODE (exp))
1748 case PREINCREMENT_EXPR:
1749 case POSTINCREMENT_EXPR:
1750 case PREDECREMENT_EXPR:
1751 case POSTDECREMENT_EXPR:
1756 case METHOD_CALL_EXPR:
1758 case TRY_CATCH_EXPR:
1759 case WITH_CLEANUP_EXPR:
1761 /* We don't warn about COND_EXPR because it may be a useful
1762 construct if either arm contains a side effect. */
1767 /* For a binding, warn if no side effect within it. */
1768 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1771 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1773 case TRUTH_ORIF_EXPR:
1774 case TRUTH_ANDIF_EXPR:
1775 /* In && or ||, warn if 2nd operand has no side effect. */
1776 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1779 if (TREE_NO_UNUSED_WARNING (exp))
1781 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
1783 /* Let people do `(foo (), 0)' without a warning. */
1784 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
1786 return warn_if_unused_value (TREE_OPERAND (exp, 1));
1790 case NON_LVALUE_EXPR:
1791 /* Don't warn about values cast to void. */
1792 if (TREE_TYPE (exp) == void_type_node)
1794 /* Don't warn about conversions not explicit in the user's program. */
1795 if (TREE_NO_UNUSED_WARNING (exp))
1797 /* Assignment to a cast usually results in a cast of a modify.
1798 Don't complain about that. There can be an arbitrary number of
1799 casts before the modify, so we must loop until we find the first
1800 non-cast expression and then test to see if that is a modify. */
1802 tree tem = TREE_OPERAND (exp, 0);
1804 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
1805 tem = TREE_OPERAND (tem, 0);
1807 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
1808 || TREE_CODE (tem) == CALL_EXPR)
1814 /* Don't warn about automatic dereferencing of references, since
1815 the user cannot control it. */
1816 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
1817 return warn_if_unused_value (TREE_OPERAND (exp, 0));
1818 /* ... fall through ... */
1821 /* Referencing a volatile value is a side effect, so don't warn. */
1822 if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
1823 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
1824 && TREE_THIS_VOLATILE (exp))
1827 warning_with_file_and_line (emit_filename, emit_lineno,
1828 "value computed is not used");
1833 /* Clear out the memory of the last expression evaluated. */
1841 /* Begin a statement which will return a value.
1842 Return the RTL_EXPR for this statement expr.
1843 The caller must save that value and pass it to expand_end_stmt_expr. */
1846 expand_start_stmt_expr ()
1851 /* Make the RTL_EXPR node temporary, not momentary,
1852 so that rtl_expr_chain doesn't become garbage. */
1853 momentary = suspend_momentary ();
1854 t = make_node (RTL_EXPR);
1855 resume_momentary (momentary);
1856 do_pending_stack_adjust ();
1857 start_sequence_for_rtl_expr (t);
1859 expr_stmts_for_value++;
1863 /* Restore the previous state at the end of a statement that returns a value.
1864 Returns a tree node representing the statement's value and the
1865 insns to compute the value.
1867 The nodes of that expression have been freed by now, so we cannot use them.
1868 But we don't want to do that anyway; the expression has already been
1869 evaluated and now we just want to use the value. So generate a RTL_EXPR
1870 with the proper type and RTL value.
1872 If the last substatement was not an expression,
1873 return something with type `void'. */
1876 expand_end_stmt_expr (t)
1881 if (last_expr_type == 0)
1883 last_expr_type = void_type_node;
1884 last_expr_value = const0_rtx;
1886 else if (last_expr_value == 0)
1887 /* There are some cases where this can happen, such as when the
1888 statement is void type. */
1889 last_expr_value = const0_rtx;
1890 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
1891 /* Remove any possible QUEUED. */
1892 last_expr_value = protect_from_queue (last_expr_value, 0);
1896 TREE_TYPE (t) = last_expr_type;
1897 RTL_EXPR_RTL (t) = last_expr_value;
1898 RTL_EXPR_SEQUENCE (t) = get_insns ();
1900 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
1904 /* Don't consider deleting this expr or containing exprs at tree level. */
1905 TREE_SIDE_EFFECTS (t) = 1;
1906 /* Propagate volatility of the actual RTL expr. */
1907 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
1910 expr_stmts_for_value--;
1915 /* Generate RTL for the start of an if-then. COND is the expression
1916 whose truth should be tested.
1918 If EXITFLAG is nonzero, this conditional is visible to
1919 `exit_something'. */
1922 expand_start_cond (cond, exitflag)
1926 struct nesting *thiscond = ALLOC_NESTING ();
1928 /* Make an entry on cond_stack for the cond we are entering. */
1930 thiscond->next = cond_stack;
1931 thiscond->all = nesting_stack;
1932 thiscond->depth = ++nesting_depth;
1933 thiscond->data.cond.next_label = gen_label_rtx ();
1934 /* Before we encounter an `else', we don't need a separate exit label
1935 unless there are supposed to be exit statements
1936 to exit this conditional. */
1937 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
1938 thiscond->data.cond.endif_label = thiscond->exit_label;
1939 cond_stack = thiscond;
1940 nesting_stack = thiscond;
1942 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
1945 /* Generate RTL between then-clause and the elseif-clause
1946 of an if-then-elseif-.... */
1949 expand_start_elseif (cond)
1952 if (cond_stack->data.cond.endif_label == 0)
1953 cond_stack->data.cond.endif_label = gen_label_rtx ();
1954 emit_jump (cond_stack->data.cond.endif_label);
1955 emit_label (cond_stack->data.cond.next_label);
1956 cond_stack->data.cond.next_label = gen_label_rtx ();
1957 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1960 /* Generate RTL between the then-clause and the else-clause
1961 of an if-then-else. */
1964 expand_start_else ()
1966 if (cond_stack->data.cond.endif_label == 0)
1967 cond_stack->data.cond.endif_label = gen_label_rtx ();
1969 emit_jump (cond_stack->data.cond.endif_label);
1970 emit_label (cond_stack->data.cond.next_label);
1971 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
1974 /* After calling expand_start_else, turn this "else" into an "else if"
1975 by providing another condition. */
1978 expand_elseif (cond)
1981 cond_stack->data.cond.next_label = gen_label_rtx ();
1982 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
1985 /* Generate RTL for the end of an if-then.
1986 Pop the record for it off of cond_stack. */
1991 struct nesting *thiscond = cond_stack;
1993 do_pending_stack_adjust ();
1994 if (thiscond->data.cond.next_label)
1995 emit_label (thiscond->data.cond.next_label);
1996 if (thiscond->data.cond.endif_label)
1997 emit_label (thiscond->data.cond.endif_label);
1999 POPSTACK (cond_stack);
2005 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2006 loop should be exited by `exit_something'. This is a loop for which
2007 `expand_continue' will jump to the top of the loop.
2009 Make an entry on loop_stack to record the labels associated with
2013 expand_start_loop (exit_flag)
2016 register struct nesting *thisloop = ALLOC_NESTING ();
2018 /* Make an entry on loop_stack for the loop we are entering. */
2020 thisloop->next = loop_stack;
2021 thisloop->all = nesting_stack;
2022 thisloop->depth = ++nesting_depth;
2023 thisloop->data.loop.start_label = gen_label_rtx ();
2024 thisloop->data.loop.end_label = gen_label_rtx ();
2025 thisloop->data.loop.alt_end_label = 0;
2026 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2027 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2028 loop_stack = thisloop;
2029 nesting_stack = thisloop;
2031 do_pending_stack_adjust ();
2033 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2034 emit_label (thisloop->data.loop.start_label);
2039 /* Like expand_start_loop but for a loop where the continuation point
2040 (for expand_continue_loop) will be specified explicitly. */
2043 expand_start_loop_continue_elsewhere (exit_flag)
2046 struct nesting *thisloop = expand_start_loop (exit_flag);
2047 loop_stack->data.loop.continue_label = gen_label_rtx ();
2051 /* Specify the continuation point for a loop started with
2052 expand_start_loop_continue_elsewhere.
2053 Use this at the point in the code to which a continue statement
2057 expand_loop_continue_here ()
2059 do_pending_stack_adjust ();
2060 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2061 emit_label (loop_stack->data.loop.continue_label);
2064 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2065 Pop the block off of loop_stack. */
2070 rtx start_label = loop_stack->data.loop.start_label;
2071 rtx insn = get_last_insn ();
2073 /* Mark the continue-point at the top of the loop if none elsewhere. */
2074 if (start_label == loop_stack->data.loop.continue_label)
2075 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2077 do_pending_stack_adjust ();
2079 /* If optimizing, perhaps reorder the loop. If the loop starts with
2080 a loop exit, roll that to the end where it will optimize together
2083 We look for the conditional branch to the exit, except that once
2084 we find such a branch, we don't look past 30 instructions.
2086 In more detail, if the loop presently looks like this (in pseudo-C):
2089 if (test) goto end_label;
2094 transform it to look like:
2100 if (test) goto end_label;
2101 goto newstart_label;
2104 Here, the `test' may actually consist of some reasonably complex
2105 code, terminating in a test. */
2109 ! (GET_CODE (insn) == JUMP_INSN
2110 && GET_CODE (PATTERN (insn)) == SET
2111 && SET_DEST (PATTERN (insn)) == pc_rtx
2112 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2116 rtx last_test_insn = NULL_RTX;
2118 /* Scan insns from the top of the loop looking for a qualified
2119 conditional exit. */
2120 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2121 insn = NEXT_INSN (insn))
2123 if (GET_CODE (insn) == NOTE)
2126 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2127 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2128 /* The code that actually moves the exit test will
2129 carefully leave BLOCK notes in their original
2130 location. That means, however, that we can't debug
2131 the exit test itself. So, we refuse to move code
2132 containing BLOCK notes at low optimization levels. */
2135 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2137 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2141 /* We've come to the end of an EH region, but
2142 never saw the beginning of that region. That
2143 means that an EH region begins before the top
2144 of the loop, and ends in the middle of it. The
2145 existence of such a situation violates a basic
2146 assumption in this code, since that would imply
2147 that even when EH_REGIONS is zero, we might
2148 move code out of an exception region. */
2152 /* We already know this INSN is a NOTE, so there's no
2153 point in looking at it to see if it's a JUMP. */
2157 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2160 if (last_test_insn && num_insns > 30)
2164 /* We don't want to move a partial EH region. Consider:
2178 This isn't legal C++, but here's what it's supposed to
2179 mean: if cond() is true, stop looping. Otherwise,
2180 call bar, and keep looping. In addition, if cond
2181 throws an exception, catch it and keep looping. Such
2182 constructs are certainy legal in LISP.
2184 We should not move the `if (cond()) 0' test since then
2185 the EH-region for the try-block would be broken up.
2186 (In this case we would the EH_BEG note for the `try'
2187 and `if cond()' but not the call to bar() or the
2190 So we don't look for tests within an EH region. */
2193 if (GET_CODE (insn) == JUMP_INSN
2194 && GET_CODE (PATTERN (insn)) == SET
2195 && SET_DEST (PATTERN (insn)) == pc_rtx)
2197 /* This is indeed a jump. */
2198 rtx dest1 = NULL_RTX;
2199 rtx dest2 = NULL_RTX;
2200 rtx potential_last_test;
2201 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2203 /* A conditional jump. */
2204 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2205 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2206 potential_last_test = insn;
2210 /* An unconditional jump. */
2211 dest1 = SET_SRC (PATTERN (insn));
2212 /* Include the BARRIER after the JUMP. */
2213 potential_last_test = NEXT_INSN (insn);
2217 if (dest1 && GET_CODE (dest1) == LABEL_REF
2218 && ((XEXP (dest1, 0)
2219 == loop_stack->data.loop.alt_end_label)
2221 == loop_stack->data.loop.end_label)))
2223 last_test_insn = potential_last_test;
2227 /* If this was a conditional jump, there may be
2228 another label at which we should look. */
2235 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2237 /* We found one. Move everything from there up
2238 to the end of the loop, and add a jump into the loop
2239 to jump to there. */
2240 register rtx newstart_label = gen_label_rtx ();
2241 register rtx start_move = start_label;
2244 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2245 then we want to move this note also. */
2246 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2247 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2248 == NOTE_INSN_LOOP_CONT))
2249 start_move = PREV_INSN (start_move);
2251 emit_label_after (newstart_label, PREV_INSN (start_move));
2253 /* Actually move the insns. Start at the beginning, and
2254 keep copying insns until we've copied the
2256 for (insn = start_move; insn; insn = next_insn)
2258 /* Figure out which insn comes after this one. We have
2259 to do this before we move INSN. */
2260 if (insn == last_test_insn)
2261 /* We've moved all the insns. */
2262 next_insn = NULL_RTX;
2264 next_insn = NEXT_INSN (insn);
2266 if (GET_CODE (insn) == NOTE
2267 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2268 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2269 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2270 NOTE_INSN_BLOCK_ENDs because the correct generation
2271 of debugging information depends on these appearing
2272 in the same order in the RTL and in the tree
2273 structure, where they are represented as BLOCKs.
2274 So, we don't move block notes. Of course, moving
2275 the code inside the block is likely to make it
2276 impossible to debug the instructions in the exit
2277 test, but such is the price of optimization. */
2280 /* Move the INSN. */
2281 reorder_insns (insn, insn, get_last_insn ());
2284 emit_jump_insn_after (gen_jump (start_label),
2285 PREV_INSN (newstart_label));
2286 emit_barrier_after (PREV_INSN (newstart_label));
2287 start_label = newstart_label;
2291 emit_jump (start_label);
2292 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2293 emit_label (loop_stack->data.loop.end_label);
2295 POPSTACK (loop_stack);
2300 /* Generate a jump to the current loop's continue-point.
2301 This is usually the top of the loop, but may be specified
2302 explicitly elsewhere. If not currently inside a loop,
2303 return 0 and do nothing; caller will print an error message. */
2306 expand_continue_loop (whichloop)
2307 struct nesting *whichloop;
2311 whichloop = loop_stack;
2314 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2319 /* Generate a jump to exit the current loop. If not currently inside a loop,
2320 return 0 and do nothing; caller will print an error message. */
2323 expand_exit_loop (whichloop)
2324 struct nesting *whichloop;
2328 whichloop = loop_stack;
2331 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2335 /* Generate a conditional jump to exit the current loop if COND
2336 evaluates to zero. If not currently inside a loop,
2337 return 0 and do nothing; caller will print an error message. */
2340 expand_exit_loop_if_false (whichloop, cond)
2341 struct nesting *whichloop;
2344 rtx label = gen_label_rtx ();
2349 whichloop = loop_stack;
2352 /* In order to handle fixups, we actually create a conditional jump
2353 around a unconditional branch to exit the loop. If fixups are
2354 necessary, they go before the unconditional branch. */
2357 do_jump (cond, NULL_RTX, label);
2358 last_insn = get_last_insn ();
2359 if (GET_CODE (last_insn) == CODE_LABEL)
2360 whichloop->data.loop.alt_end_label = last_insn;
2361 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2368 /* Return nonzero if the loop nest is empty. Else return zero. */
2371 stmt_loop_nest_empty ()
2373 return (loop_stack == NULL);
2376 /* Return non-zero if we should preserve sub-expressions as separate
2377 pseudos. We never do so if we aren't optimizing. We always do so
2378 if -fexpensive-optimizations.
2380 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2381 the loop may still be a small one. */
2384 preserve_subexpressions_p ()
2388 if (flag_expensive_optimizations)
2391 if (optimize == 0 || loop_stack == 0)
2394 insn = get_last_insn_anywhere ();
2397 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2398 < n_non_fixed_regs * 3));
2402 /* Generate a jump to exit the current loop, conditional, binding contour
2403 or case statement. Not all such constructs are visible to this function,
2404 only those started with EXIT_FLAG nonzero. Individual languages use
2405 the EXIT_FLAG parameter to control which kinds of constructs you can
2408 If not currently inside anything that can be exited,
2409 return 0 and do nothing; caller will print an error message. */
2412 expand_exit_something ()
2416 for (n = nesting_stack; n; n = n->all)
2417 if (n->exit_label != 0)
2419 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2426 /* Generate RTL to return from the current function, with no value.
2427 (That is, we do not do anything about returning any value.) */
2430 expand_null_return ()
2432 struct nesting *block = block_stack;
2435 /* Does any pending block have cleanups? */
2437 while (block && block->data.block.cleanups == 0)
2438 block = block->next;
2440 /* If yes, use a goto to return, since that runs cleanups. */
2442 expand_null_return_1 (last_insn, block != 0);
2445 /* Generate RTL to return from the current function, with value VAL. */
2448 expand_value_return (val)
2451 struct nesting *block = block_stack;
2452 rtx last_insn = get_last_insn ();
2453 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2455 /* Copy the value to the return location
2456 unless it's already there. */
2458 if (return_reg != val)
2460 #ifdef PROMOTE_FUNCTION_RETURN
2461 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2462 int unsignedp = TREE_UNSIGNED (type);
2463 enum machine_mode mode
2464 = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)),
2467 if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode)
2468 convert_move (return_reg, val, unsignedp);
2471 emit_move_insn (return_reg, val);
2473 if (GET_CODE (return_reg) == REG
2474 && REGNO (return_reg) < FIRST_PSEUDO_REGISTER)
2475 emit_insn (gen_rtx_USE (VOIDmode, return_reg));
2476 /* Handle calls that return values in multiple non-contiguous locations.
2477 The Irix 6 ABI has examples of this. */
2478 else if (GET_CODE (return_reg) == PARALLEL)
2482 for (i = 0; i < XVECLEN (return_reg, 0); i++)
2484 rtx x = XEXP (XVECEXP (return_reg, 0, i), 0);
2486 if (GET_CODE (x) == REG
2487 && REGNO (x) < FIRST_PSEUDO_REGISTER)
2488 emit_insn (gen_rtx_USE (VOIDmode, x));
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.
2498 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2500 expand_null_return_1 (last_insn, block != 0);
2503 /* Output a return with no value. If LAST_INSN is nonzero,
2504 pretend that the return takes place after LAST_INSN.
2505 If USE_GOTO is nonzero then don't use a return instruction;
2506 go to the return label instead. This causes any cleanups
2507 of pending blocks to be executed normally. */
2510 expand_null_return_1 (last_insn, use_goto)
2514 rtx end_label = cleanup_label ? cleanup_label : return_label;
2516 clear_pending_stack_adjust ();
2517 do_pending_stack_adjust ();
2520 /* PCC-struct return always uses an epilogue. */
2521 if (current_function_returns_pcc_struct || use_goto)
2524 end_label = return_label = gen_label_rtx ();
2525 expand_goto_internal (NULL_TREE, end_label, last_insn);
2529 /* Otherwise output a simple return-insn if one is available,
2530 unless it won't do the job. */
2532 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2534 emit_jump_insn (gen_return ());
2540 /* Otherwise jump to the epilogue. */
2541 expand_goto_internal (NULL_TREE, end_label, last_insn);
2544 /* Generate RTL to evaluate the expression RETVAL and return it
2545 from the current function. */
2548 expand_return (retval)
2551 /* If there are any cleanups to be performed, then they will
2552 be inserted following LAST_INSN. It is desirable
2553 that the last_insn, for such purposes, should be the
2554 last insn before computing the return value. Otherwise, cleanups
2555 which call functions can clobber the return value. */
2556 /* ??? rms: I think that is erroneous, because in C++ it would
2557 run destructors on variables that might be used in the subsequent
2558 computation of the return value. */
2560 register rtx val = 0;
2565 /* If function wants no value, give it none. */
2566 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2568 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2570 expand_null_return ();
2574 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2575 /* This is not sufficient. We also need to watch for cleanups of the
2576 expression we are about to expand. Unfortunately, we cannot know
2577 if it has cleanups until we expand it, and we want to change how we
2578 expand it depending upon if we need cleanups. We can't win. */
2580 cleanups = any_pending_cleanups (1);
2585 if (TREE_CODE (retval) == RESULT_DECL)
2586 retval_rhs = retval;
2587 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2588 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2589 retval_rhs = TREE_OPERAND (retval, 1);
2590 else if (TREE_TYPE (retval) == void_type_node)
2591 /* Recognize tail-recursive call to void function. */
2592 retval_rhs = retval;
2594 retval_rhs = NULL_TREE;
2596 /* Only use `last_insn' if there are cleanups which must be run. */
2597 if (cleanups || cleanup_label != 0)
2598 last_insn = get_last_insn ();
2600 /* Distribute return down conditional expr if either of the sides
2601 may involve tail recursion (see test below). This enhances the number
2602 of tail recursions we see. Don't do this always since it can produce
2603 sub-optimal code in some cases and we distribute assignments into
2604 conditional expressions when it would help. */
2606 if (optimize && retval_rhs != 0
2607 && frame_offset == 0
2608 && TREE_CODE (retval_rhs) == COND_EXPR
2609 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2610 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2612 rtx label = gen_label_rtx ();
2615 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2616 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2617 DECL_RESULT (current_function_decl),
2618 TREE_OPERAND (retval_rhs, 1));
2619 TREE_SIDE_EFFECTS (expr) = 1;
2620 expand_return (expr);
2623 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2624 DECL_RESULT (current_function_decl),
2625 TREE_OPERAND (retval_rhs, 2));
2626 TREE_SIDE_EFFECTS (expr) = 1;
2627 expand_return (expr);
2631 /* Attempt to optimize the call if it is tail recursive. */
2632 if (optimize_tail_recursion (retval_rhs, last_insn))
2636 /* This optimization is safe if there are local cleanups
2637 because expand_null_return takes care of them.
2638 ??? I think it should also be safe when there is a cleanup label,
2639 because expand_null_return takes care of them, too.
2640 Any reason why not? */
2641 if (HAVE_return && cleanup_label == 0
2642 && ! current_function_returns_pcc_struct
2643 && BRANCH_COST <= 1)
2645 /* If this is return x == y; then generate
2646 if (x == y) return 1; else return 0;
2647 if we can do it with explicit return insns and branches are cheap,
2648 but not if we have the corresponding scc insn. */
2651 switch (TREE_CODE (retval_rhs))
2677 case TRUTH_ANDIF_EXPR:
2678 case TRUTH_ORIF_EXPR:
2679 case TRUTH_AND_EXPR:
2681 case TRUTH_NOT_EXPR:
2682 case TRUTH_XOR_EXPR:
2685 op0 = gen_label_rtx ();
2686 jumpifnot (retval_rhs, op0);
2687 expand_value_return (const1_rtx);
2689 expand_value_return (const0_rtx);
2698 #endif /* HAVE_return */
2700 /* If the result is an aggregate that is being returned in one (or more)
2701 registers, load the registers here. The compiler currently can't handle
2702 copying a BLKmode value into registers. We could put this code in a
2703 more general area (for use by everyone instead of just function
2704 call/return), but until this feature is generally usable it is kept here
2705 (and in expand_call). The value must go into a pseudo in case there
2706 are cleanups that will clobber the real return register. */
2709 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
2710 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2712 int i, bitpos, xbitpos;
2713 int big_endian_correction = 0;
2714 int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2715 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
2716 int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),
2717 (unsigned int)BITS_PER_WORD);
2718 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
2719 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
2720 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
2721 enum machine_mode tmpmode, result_reg_mode;
2723 /* Structures whose size is not a multiple of a word are aligned
2724 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2725 machine, this means we must skip the empty high order bytes when
2726 calculating the bit offset. */
2727 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
2728 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
2731 /* Copy the structure BITSIZE bits at a time. */
2732 for (bitpos = 0, xbitpos = big_endian_correction;
2733 bitpos < bytes * BITS_PER_UNIT;
2734 bitpos += bitsize, xbitpos += bitsize)
2736 /* We need a new destination pseudo each time xbitpos is
2737 on a word boundary and when xbitpos == big_endian_correction
2738 (the first time through). */
2739 if (xbitpos % BITS_PER_WORD == 0
2740 || xbitpos == big_endian_correction)
2742 /* Generate an appropriate register. */
2743 dst = gen_reg_rtx (word_mode);
2744 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
2746 /* Clobber the destination before we move anything into it. */
2747 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
2750 /* We need a new source operand each time bitpos is on a word
2752 if (bitpos % BITS_PER_WORD == 0)
2753 src = operand_subword_force (result_val,
2754 bitpos / BITS_PER_WORD,
2757 /* Use bitpos for the source extraction (left justified) and
2758 xbitpos for the destination store (right justified). */
2759 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
2760 extract_bit_field (src, bitsize,
2761 bitpos % BITS_PER_WORD, 1,
2762 NULL_RTX, word_mode,
2764 bitsize / BITS_PER_UNIT,
2766 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
2769 /* Find the smallest integer mode large enough to hold the
2770 entire structure and use that mode instead of BLKmode
2771 on the USE insn for the return register. */
2772 bytes = int_size_in_bytes (TREE_TYPE (retval_rhs));
2773 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2774 tmpmode != MAX_MACHINE_MODE;
2775 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
2777 /* Have we found a large enough mode? */
2778 if (GET_MODE_SIZE (tmpmode) >= bytes)
2782 /* No suitable mode found. */
2783 if (tmpmode == MAX_MACHINE_MODE)
2786 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode);
2788 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
2789 result_reg_mode = word_mode;
2791 result_reg_mode = tmpmode;
2792 result_reg = gen_reg_rtx (result_reg_mode);
2795 for (i = 0; i < n_regs; i++)
2796 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
2799 if (tmpmode != result_reg_mode)
2800 result_reg = gen_lowpart (tmpmode, result_reg);
2802 expand_value_return (result_reg);
2806 && TREE_TYPE (retval_rhs) != void_type_node
2807 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG)
2809 /* Calculate the return value into a pseudo reg. */
2810 val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl)));
2811 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
2812 val = force_not_mem (val);
2814 /* Return the calculated value, doing cleanups first. */
2815 expand_value_return (val);
2819 /* No cleanups or no hard reg used;
2820 calculate value into hard return reg. */
2821 expand_expr (retval, const0_rtx, VOIDmode, 0);
2823 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl)));
2827 /* Return 1 if the end of the generated RTX is not a barrier.
2828 This means code already compiled can drop through. */
2831 drop_through_at_end_p ()
2833 rtx insn = get_last_insn ();
2834 while (insn && GET_CODE (insn) == NOTE)
2835 insn = PREV_INSN (insn);
2836 return insn && GET_CODE (insn) != BARRIER;
2839 /* Test CALL_EXPR to determine if it is a potential tail recursion call
2840 and emit code to optimize the tail recursion. LAST_INSN indicates where
2841 to place the jump to the tail recursion label. Return TRUE if the
2842 call was optimized into a goto.
2844 This is only used by expand_return, but expand_call is expected to
2848 optimize_tail_recursion (call_expr, last_insn)
2852 /* For tail-recursive call to current function,
2853 just jump back to the beginning.
2854 It's unsafe if any auto variable in this function
2855 has its address taken; for simplicity,
2856 require stack frame to be empty. */
2857 if (optimize && call_expr != 0
2858 && frame_offset == 0
2859 && TREE_CODE (call_expr) == CALL_EXPR
2860 && TREE_CODE (TREE_OPERAND (call_expr, 0)) == ADDR_EXPR
2861 && TREE_OPERAND (TREE_OPERAND (call_expr, 0), 0) == current_function_decl
2862 /* Finish checking validity, and if valid emit code
2863 to set the argument variables for the new call. */
2864 && tail_recursion_args (TREE_OPERAND (call_expr, 1),
2865 DECL_ARGUMENTS (current_function_decl)))
2867 if (tail_recursion_label == 0)
2869 tail_recursion_label = gen_label_rtx ();
2870 emit_label_after (tail_recursion_label,
2871 tail_recursion_reentry);
2874 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
2882 /* Emit code to alter this function's formal parms for a tail-recursive call.
2883 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2884 FORMALS is the chain of decls of formals.
2885 Return 1 if this can be done;
2886 otherwise return 0 and do not emit any code. */
2889 tail_recursion_args (actuals, formals)
2890 tree actuals, formals;
2892 register tree a = actuals, f = formals;
2894 register rtx *argvec;
2896 /* Check that number and types of actuals are compatible
2897 with the formals. This is not always true in valid C code.
2898 Also check that no formal needs to be addressable
2899 and that all formals are scalars. */
2901 /* Also count the args. */
2903 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
2905 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
2906 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
2908 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
2911 if (a != 0 || f != 0)
2914 /* Compute all the actuals. */
2916 argvec = (rtx *) alloca (i * sizeof (rtx));
2918 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2919 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
2921 /* Find which actual values refer to current values of previous formals.
2922 Copy each of them now, before any formal is changed. */
2924 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
2928 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
2929 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
2930 { copy = 1; break; }
2932 argvec[i] = copy_to_reg (argvec[i]);
2935 /* Store the values of the actuals into the formals. */
2937 for (f = formals, a = actuals, i = 0; f;
2938 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
2940 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
2941 emit_move_insn (DECL_RTL (f), argvec[i]);
2943 convert_move (DECL_RTL (f), argvec[i],
2944 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
2951 /* Generate the RTL code for entering a binding contour.
2952 The variables are declared one by one, by calls to `expand_decl'.
2954 EXIT_FLAG is nonzero if this construct should be visible to
2955 `exit_something'. */
2958 expand_start_bindings (exit_flag)
2961 struct nesting *thisblock = ALLOC_NESTING ();
2962 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
2964 /* Make an entry on block_stack for the block we are entering. */
2966 thisblock->next = block_stack;
2967 thisblock->all = nesting_stack;
2968 thisblock->depth = ++nesting_depth;
2969 thisblock->data.block.stack_level = 0;
2970 thisblock->data.block.cleanups = 0;
2971 thisblock->data.block.function_call_count = 0;
2972 thisblock->data.block.exception_region = 0;
2973 thisblock->data.block.target_temp_slot_level = target_temp_slot_level;
2975 thisblock->data.block.conditional_code = 0;
2976 thisblock->data.block.last_unconditional_cleanup = note;
2977 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
2980 && !(block_stack->data.block.cleanups == NULL_TREE
2981 && block_stack->data.block.outer_cleanups == NULL_TREE))
2982 thisblock->data.block.outer_cleanups
2983 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
2984 block_stack->data.block.outer_cleanups);
2986 thisblock->data.block.outer_cleanups = 0;
2987 thisblock->data.block.label_chain = 0;
2988 thisblock->data.block.innermost_stack_block = stack_block_stack;
2989 thisblock->data.block.first_insn = note;
2990 thisblock->data.block.block_start_count = ++block_start_count;
2991 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
2992 block_stack = thisblock;
2993 nesting_stack = thisblock;
2995 /* Make a new level for allocating stack slots. */
2999 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3000 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3001 expand_expr are made. After we end the region, we know that all
3002 space for all temporaries that were created by TARGET_EXPRs will be
3003 destroyed and their space freed for reuse. */
3006 expand_start_target_temps ()
3008 /* This is so that even if the result is preserved, the space
3009 allocated will be freed, as we know that it is no longer in use. */
3012 /* Start a new binding layer that will keep track of all cleanup
3013 actions to be performed. */
3014 expand_start_bindings (0);
3016 target_temp_slot_level = temp_slot_level;
3020 expand_end_target_temps ()
3022 expand_end_bindings (NULL_TREE, 0, 0);
3024 /* This is so that even if the result is preserved, the space
3025 allocated will be freed, as we know that it is no longer in use. */
3029 /* Mark top block of block_stack as an implicit binding for an
3030 exception region. This is used to prevent infinite recursion when
3031 ending a binding with expand_end_bindings. It is only ever called
3032 by expand_eh_region_start, as that it the only way to create a
3033 block stack for a exception region. */
3036 mark_block_as_eh_region ()
3038 block_stack->data.block.exception_region = 1;
3039 if (block_stack->next
3040 && block_stack->next->data.block.conditional_code)
3042 block_stack->data.block.conditional_code
3043 = block_stack->next->data.block.conditional_code;
3044 block_stack->data.block.last_unconditional_cleanup
3045 = block_stack->next->data.block.last_unconditional_cleanup;
3046 block_stack->data.block.cleanup_ptr
3047 = block_stack->next->data.block.cleanup_ptr;
3051 /* True if we are currently emitting insns in an area of output code
3052 that is controlled by a conditional expression. This is used by
3053 the cleanup handling code to generate conditional cleanup actions. */
3056 conditional_context ()
3058 return block_stack && block_stack->data.block.conditional_code;
3061 /* Mark top block of block_stack as not for an implicit binding for an
3062 exception region. This is only ever done by expand_eh_region_end
3063 to let expand_end_bindings know that it is being called explicitly
3064 to end the binding layer for just the binding layer associated with
3065 the exception region, otherwise expand_end_bindings would try and
3066 end all implicit binding layers for exceptions regions, and then
3067 one normal binding layer. */
3070 mark_block_as_not_eh_region ()
3072 block_stack->data.block.exception_region = 0;
3075 /* True if the top block of block_stack was marked as for an exception
3076 region by mark_block_as_eh_region. */
3081 return block_stack && block_stack->data.block.exception_region;
3084 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3085 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3089 remember_end_note (block)
3090 register tree block;
3092 BLOCK_END_NOTE (block) = last_block_end_note;
3093 last_block_end_note = NULL_RTX;
3096 /* Emit a handler label for a nonlocal goto handler.
3097 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3100 expand_nl_handler_label (slot, before_insn)
3101 rtx slot, before_insn;
3104 rtx handler_label = gen_label_rtx ();
3106 /* Don't let jump_optimize delete the handler. */
3107 LABEL_PRESERVE_P (handler_label) = 1;
3110 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3111 insns = get_insns ();
3113 emit_insns_before (insns, before_insn);
3115 emit_label (handler_label);
3118 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3121 expand_nl_goto_receiver ()
3123 #ifdef HAVE_nonlocal_goto
3124 if (! HAVE_nonlocal_goto)
3126 /* First adjust our frame pointer to its actual value. It was
3127 previously set to the start of the virtual area corresponding to
3128 the stacked variables when we branched here and now needs to be
3129 adjusted to the actual hardware fp value.
3131 Assignments are to virtual registers are converted by
3132 instantiate_virtual_regs into the corresponding assignment
3133 to the underlying register (fp in this case) that makes
3134 the original assignment true.
3135 So the following insn will actually be
3136 decrementing fp by STARTING_FRAME_OFFSET. */
3137 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3139 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3140 if (fixed_regs[ARG_POINTER_REGNUM])
3142 #ifdef ELIMINABLE_REGS
3143 /* If the argument pointer can be eliminated in favor of the
3144 frame pointer, we don't need to restore it. We assume here
3145 that if such an elimination is present, it can always be used.
3146 This is the case on all known machines; if we don't make this
3147 assumption, we do unnecessary saving on many machines. */
3148 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3151 for (i = 0; i < sizeof elim_regs / sizeof elim_regs[0]; i++)
3152 if (elim_regs[i].from == ARG_POINTER_REGNUM
3153 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3156 if (i == sizeof elim_regs / sizeof elim_regs [0])
3159 /* Now restore our arg pointer from the address at which it
3160 was saved in our stack frame.
3161 If there hasn't be space allocated for it yet, make
3163 if (arg_pointer_save_area == 0)
3164 arg_pointer_save_area
3165 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3166 emit_move_insn (virtual_incoming_args_rtx,
3167 /* We need a pseudo here, or else
3168 instantiate_virtual_regs_1 complains. */
3169 copy_to_reg (arg_pointer_save_area));
3174 #ifdef HAVE_nonlocal_goto_receiver
3175 if (HAVE_nonlocal_goto_receiver)
3176 emit_insn (gen_nonlocal_goto_receiver ());
3180 /* Make handlers for nonlocal gotos taking place in the function calls in
3184 expand_nl_goto_receivers (thisblock)
3185 struct nesting *thisblock;
3188 rtx afterward = gen_label_rtx ();
3192 /* Record the handler address in the stack slot for that purpose,
3193 during this block, saving and restoring the outer value. */
3194 if (thisblock->next != 0)
3195 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3197 rtx save_receiver = gen_reg_rtx (Pmode);
3198 emit_move_insn (XEXP (slot, 0), save_receiver);
3201 emit_move_insn (save_receiver, XEXP (slot, 0));
3202 insns = get_insns ();
3204 emit_insns_before (insns, thisblock->data.block.first_insn);
3207 /* Jump around the handlers; they run only when specially invoked. */
3208 emit_jump (afterward);
3210 /* Make a separate handler for each label. */
3211 link = nonlocal_labels;
3212 slot = nonlocal_goto_handler_slots;
3213 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3214 /* Skip any labels we shouldn't be able to jump to from here,
3215 we generate one special handler for all of them below which just calls
3217 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3219 expand_nl_handler_label (XEXP (slot, 0),
3220 thisblock->data.block.first_insn);
3221 expand_nl_goto_receiver ();
3223 /* Jump to the "real" nonlocal label. */
3224 expand_goto (TREE_VALUE (link));
3227 /* A second pass over all nonlocal labels; this time we handle those
3228 we should not be able to jump to at this point. */
3229 link = nonlocal_labels;
3230 slot = nonlocal_goto_handler_slots;
3232 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3233 if (DECL_TOO_LATE (TREE_VALUE (link)))
3235 expand_nl_handler_label (XEXP (slot, 0),
3236 thisblock->data.block.first_insn);
3242 expand_nl_goto_receiver ();
3243 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3248 emit_label (afterward);
3251 /* Generate RTL code to terminate a binding contour.
3252 VARS is the chain of VAR_DECL nodes
3253 for the variables bound in this contour.
3254 MARK_ENDS is nonzero if we should put a note at the beginning
3255 and end of this binding contour.
3257 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3258 (That is true automatically if the contour has a saved stack level.) */
3261 expand_end_bindings (vars, mark_ends, dont_jump_in)
3266 register struct nesting *thisblock;
3269 while (block_stack->data.block.exception_region)
3271 /* Because we don't need or want a new temporary level and
3272 because we didn't create one in expand_eh_region_start,
3273 create a fake one now to avoid removing one in
3274 expand_end_bindings. */
3277 block_stack->data.block.exception_region = 0;
3279 expand_end_bindings (NULL_TREE, 0, 0);
3282 /* Since expand_eh_region_start does an expand_start_bindings, we
3283 have to first end all the bindings that were created by
3284 expand_eh_region_start. */
3286 thisblock = block_stack;
3289 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3290 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL
3291 && ! DECL_IN_SYSTEM_HEADER (decl)
3292 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3293 warning_with_decl (decl, "unused variable `%s'");
3295 if (thisblock->exit_label)
3297 do_pending_stack_adjust ();
3298 emit_label (thisblock->exit_label);
3301 /* If necessary, make handlers for nonlocal gotos taking
3302 place in the function calls in this block. */
3303 if (function_call_count != thisblock->data.block.function_call_count
3305 /* Make handler for outermost block
3306 if there were any nonlocal gotos to this function. */
3307 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3308 /* Make handler for inner block if it has something
3309 special to do when you jump out of it. */
3310 : (thisblock->data.block.cleanups != 0
3311 || thisblock->data.block.stack_level != 0)))
3312 expand_nl_goto_receivers (thisblock);
3314 /* Don't allow jumping into a block that has a stack level.
3315 Cleanups are allowed, though. */
3317 || thisblock->data.block.stack_level != 0)
3319 struct label_chain *chain;
3321 /* Any labels in this block are no longer valid to go to.
3322 Mark them to cause an error message. */
3323 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3325 DECL_TOO_LATE (chain->label) = 1;
3326 /* If any goto without a fixup came to this label,
3327 that must be an error, because gotos without fixups
3328 come from outside all saved stack-levels. */
3329 if (TREE_ADDRESSABLE (chain->label))
3330 error_with_decl (chain->label,
3331 "label `%s' used before containing binding contour");
3335 /* Restore stack level in effect before the block
3336 (only if variable-size objects allocated). */
3337 /* Perform any cleanups associated with the block. */
3339 if (thisblock->data.block.stack_level != 0
3340 || thisblock->data.block.cleanups != 0)
3342 /* Only clean up here if this point can actually be reached. */
3343 int reachable = GET_CODE (get_last_insn ()) != BARRIER;
3345 /* Don't let cleanups affect ({...}) constructs. */
3346 int old_expr_stmts_for_value = expr_stmts_for_value;
3347 rtx old_last_expr_value = last_expr_value;
3348 tree old_last_expr_type = last_expr_type;
3349 expr_stmts_for_value = 0;
3351 /* Do the cleanups. */
3352 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3354 do_pending_stack_adjust ();
3356 expr_stmts_for_value = old_expr_stmts_for_value;
3357 last_expr_value = old_last_expr_value;
3358 last_expr_type = old_last_expr_type;
3360 /* Restore the stack level. */
3362 if (reachable && thisblock->data.block.stack_level != 0)
3364 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3365 thisblock->data.block.stack_level, NULL_RTX);
3366 if (nonlocal_goto_handler_slots != 0)
3367 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3371 /* Any gotos out of this block must also do these things.
3372 Also report any gotos with fixups that came to labels in this
3374 fixup_gotos (thisblock,
3375 thisblock->data.block.stack_level,
3376 thisblock->data.block.cleanups,
3377 thisblock->data.block.first_insn,
3381 /* Mark the beginning and end of the scope if requested.
3382 We do this now, after running cleanups on the variables
3383 just going out of scope, so they are in scope for their cleanups. */
3386 last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3388 /* Get rid of the beginning-mark if we don't make an end-mark. */
3389 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3391 /* If doing stupid register allocation, make sure lives of all
3392 register variables declared here extend thru end of scope. */
3395 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3397 rtx rtl = DECL_RTL (decl);
3398 if (TREE_CODE (decl) == VAR_DECL && rtl != 0)
3402 /* Restore the temporary level of TARGET_EXPRs. */
3403 target_temp_slot_level = thisblock->data.block.target_temp_slot_level;
3405 /* Restore block_stack level for containing block. */
3407 stack_block_stack = thisblock->data.block.innermost_stack_block;
3408 POPSTACK (block_stack);
3410 /* Pop the stack slot nesting and free any slots at this level. */
3414 /* Generate RTL for the automatic variable declaration DECL.
3415 (Other kinds of declarations are simply ignored if seen here.) */
3421 struct nesting *thisblock = block_stack;
3424 type = TREE_TYPE (decl);
3426 /* Only automatic variables need any expansion done.
3427 Static and external variables, and external functions,
3428 will be handled by `assemble_variable' (called from finish_decl).
3429 TYPE_DECL and CONST_DECL require nothing.
3430 PARM_DECLs are handled in `assign_parms'. */
3432 if (TREE_CODE (decl) != VAR_DECL)
3434 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3437 /* Create the RTL representation for the variable. */
3439 if (type == error_mark_node)
3440 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3441 else if (DECL_SIZE (decl) == 0)
3442 /* Variable with incomplete type. */
3444 if (DECL_INITIAL (decl) == 0)
3445 /* Error message was already done; now avoid a crash. */
3446 DECL_RTL (decl) = assign_stack_temp (DECL_MODE (decl), 0, 1);
3448 /* An initializer is going to decide the size of this array.
3449 Until we know the size, represent its address with a reg. */
3450 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3451 MEM_SET_IN_STRUCT_P (DECL_RTL (decl), AGGREGATE_TYPE_P (type));
3453 else if (DECL_MODE (decl) != BLKmode
3454 /* If -ffloat-store, don't put explicit float vars
3456 && !(flag_float_store
3457 && TREE_CODE (type) == REAL_TYPE)
3458 && ! TREE_THIS_VOLATILE (decl)
3459 && ! TREE_ADDRESSABLE (decl)
3460 && (DECL_REGISTER (decl) || ! obey_regdecls)
3461 /* if -fcheck-memory-usage, check all variables. */
3462 && ! current_function_check_memory_usage)
3464 /* Automatic variable that can go in a register. */
3465 int unsignedp = TREE_UNSIGNED (type);
3466 enum machine_mode reg_mode
3467 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3469 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3470 mark_user_reg (DECL_RTL (decl));
3472 if (POINTER_TYPE_P (type))
3473 mark_reg_pointer (DECL_RTL (decl),
3474 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))
3478 else if (TREE_CODE (DECL_SIZE (decl)) == INTEGER_CST
3479 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3480 && (TREE_INT_CST_HIGH (DECL_SIZE (decl)) != 0
3481 || (TREE_INT_CST_LOW (DECL_SIZE (decl))
3482 > STACK_CHECK_MAX_VAR_SIZE * BITS_PER_UNIT))))
3484 /* Variable of fixed size that goes on the stack. */
3488 /* If we previously made RTL for this decl, it must be an array
3489 whose size was determined by the initializer.
3490 The old address was a register; set that register now
3491 to the proper address. */
3492 if (DECL_RTL (decl) != 0)
3494 if (GET_CODE (DECL_RTL (decl)) != MEM
3495 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3497 oldaddr = XEXP (DECL_RTL (decl), 0);
3500 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3501 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3502 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3504 /* Set alignment we actually gave this decl. */
3505 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3506 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3510 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3511 if (addr != oldaddr)
3512 emit_move_insn (oldaddr, addr);
3515 /* If this is a memory ref that contains aggregate components,
3516 mark it as such for cse and loop optimize. */
3517 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3518 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3520 /* If this is in memory because of -ffloat-store,
3521 set the volatile bit, to prevent optimizations from
3522 undoing the effects. */
3523 if (flag_float_store && TREE_CODE (type) == REAL_TYPE)
3524 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3527 MEM_ALIAS_SET (DECL_RTL (decl)) = get_alias_set (decl);
3530 /* Dynamic-size object: must push space on the stack. */
3534 /* Record the stack pointer on entry to block, if have
3535 not already done so. */
3536 if (thisblock->data.block.stack_level == 0)
3538 do_pending_stack_adjust ();
3539 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3540 &thisblock->data.block.stack_level,
3541 thisblock->data.block.first_insn);
3542 stack_block_stack = thisblock;
3545 /* Compute the variable's size, in bytes. */
3546 size = expand_expr (size_binop (CEIL_DIV_EXPR,
3548 size_int (BITS_PER_UNIT)),
3549 NULL_RTX, VOIDmode, 0);
3552 /* Allocate space on the stack for the variable. Note that
3553 DECL_ALIGN says how the variable is to be aligned and we
3554 cannot use it to conclude anything about the alignment of
3556 address = allocate_dynamic_stack_space (size, NULL_RTX,
3557 TYPE_ALIGN (TREE_TYPE (decl)));
3559 /* Reference the variable indirect through that rtx. */
3560 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3562 /* If this is a memory ref that contains aggregate components,
3563 mark it as such for cse and loop optimize. */
3564 MEM_SET_IN_STRUCT_P (DECL_RTL (decl),
3565 AGGREGATE_TYPE_P (TREE_TYPE (decl)));
3567 /* Indicate the alignment we actually gave this variable. */
3568 #ifdef STACK_BOUNDARY
3569 DECL_ALIGN (decl) = STACK_BOUNDARY;
3571 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3575 if (TREE_THIS_VOLATILE (decl))
3576 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
3577 #if 0 /* A variable is not necessarily unchanging
3578 just because it is const. RTX_UNCHANGING_P
3579 means no change in the function,
3580 not merely no change in the variable's scope.
3581 It is correct to set RTX_UNCHANGING_P if the variable's scope
3582 is the whole function. There's no convenient way to test that. */
3583 if (TREE_READONLY (decl))
3584 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
3587 /* If doing stupid register allocation, make sure life of any
3588 register variable starts here, at the start of its scope. */
3591 use_variable (DECL_RTL (decl));
3596 /* Emit code to perform the initialization of a declaration DECL. */
3599 expand_decl_init (decl)
3602 int was_used = TREE_USED (decl);
3604 /* If this is a CONST_DECL, we don't have to generate any code, but
3605 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3606 to be set while in the obstack containing the constant. If we don't
3607 do this, we can lose if we have functions nested three deep and the middle
3608 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3609 the innermost function is the first to expand that STRING_CST. */
3610 if (TREE_CODE (decl) == CONST_DECL)
3612 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3613 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3614 EXPAND_INITIALIZER);
3618 if (TREE_STATIC (decl))
3621 /* Compute and store the initial value now. */
3623 if (DECL_INITIAL (decl) == error_mark_node)
3625 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3627 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3628 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3629 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3633 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
3635 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
3636 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
3640 /* Don't let the initialization count as "using" the variable. */
3641 TREE_USED (decl) = was_used;
3643 /* Free any temporaries we made while initializing the decl. */
3644 preserve_temp_slots (NULL_RTX);
3648 /* CLEANUP is an expression to be executed at exit from this binding contour;
3649 for example, in C++, it might call the destructor for this variable.
3651 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3652 CLEANUP multiple times, and have the correct semantics. This
3653 happens in exception handling, for gotos, returns, breaks that
3654 leave the current scope.
3656 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3657 that is not associated with any particular variable. */
3660 expand_decl_cleanup (decl, cleanup)
3663 struct nesting *thisblock = block_stack;
3665 /* Error if we are not in any block. */
3669 /* Record the cleanup if there is one. */
3675 tree *cleanups = &thisblock->data.block.cleanups;
3676 int cond_context = conditional_context ();
3680 rtx flag = gen_reg_rtx (word_mode);
3685 emit_move_insn (flag, const0_rtx);
3686 set_flag_0 = get_insns ();
3689 thisblock->data.block.last_unconditional_cleanup
3690 = emit_insns_after (set_flag_0,
3691 thisblock->data.block.last_unconditional_cleanup);
3693 emit_move_insn (flag, const1_rtx);
3695 /* All cleanups must be on the function_obstack. */
3696 push_obstacks_nochange ();
3697 resume_temporary_allocation ();
3699 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
3700 DECL_RTL (cond) = flag;
3702 /* Conditionalize the cleanup. */
3703 cleanup = build (COND_EXPR, void_type_node,
3704 truthvalue_conversion (cond),
3705 cleanup, integer_zero_node);
3706 cleanup = fold (cleanup);
3710 cleanups = thisblock->data.block.cleanup_ptr;
3713 /* All cleanups must be on the function_obstack. */
3714 push_obstacks_nochange ();
3715 resume_temporary_allocation ();
3716 cleanup = unsave_expr (cleanup);
3719 t = *cleanups = temp_tree_cons (decl, cleanup, *cleanups);
3722 /* If this block has a cleanup, it belongs in stack_block_stack. */
3723 stack_block_stack = thisblock;
3730 /* If this was optimized so that there is no exception region for the
3731 cleanup, then mark the TREE_LIST node, so that we can later tell
3732 if we need to call expand_eh_region_end. */
3733 if (! using_eh_for_cleanups_p
3734 || expand_eh_region_start_tree (decl, cleanup))
3735 TREE_ADDRESSABLE (t) = 1;
3736 /* If that started a new EH region, we're in a new block. */
3737 thisblock = block_stack;
3744 thisblock->data.block.last_unconditional_cleanup
3745 = emit_insns_after (seq,
3746 thisblock->data.block.last_unconditional_cleanup);
3750 thisblock->data.block.last_unconditional_cleanup
3752 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3758 /* Like expand_decl_cleanup, but suppress generating an exception handler
3759 to perform the cleanup. */
3762 expand_decl_cleanup_no_eh (decl, cleanup)
3765 int save_eh = using_eh_for_cleanups_p;
3768 using_eh_for_cleanups_p = 0;
3769 result = expand_decl_cleanup (decl, cleanup);
3770 using_eh_for_cleanups_p = save_eh;
3775 /* Arrange for the top element of the dynamic cleanup chain to be
3776 popped if we exit the current binding contour. DECL is the
3777 associated declaration, if any, otherwise NULL_TREE. If the
3778 current contour is left via an exception, then __sjthrow will pop
3779 the top element off the dynamic cleanup chain. The code that
3780 avoids doing the action we push into the cleanup chain in the
3781 exceptional case is contained in expand_cleanups.
3783 This routine is only used by expand_eh_region_start, and that is
3784 the only way in which an exception region should be started. This
3785 routine is only used when using the setjmp/longjmp codegen method
3786 for exception handling. */
3789 expand_dcc_cleanup (decl)
3792 struct nesting *thisblock = block_stack;
3795 /* Error if we are not in any block. */
3799 /* Record the cleanup for the dynamic handler chain. */
3801 /* All cleanups must be on the function_obstack. */
3802 push_obstacks_nochange ();
3803 resume_temporary_allocation ();
3804 cleanup = make_node (POPDCC_EXPR);
3807 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
3808 thisblock->data.block.cleanups
3809 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3811 /* If this block has a cleanup, it belongs in stack_block_stack. */
3812 stack_block_stack = thisblock;
3816 /* Arrange for the top element of the dynamic handler chain to be
3817 popped if we exit the current binding contour. DECL is the
3818 associated declaration, if any, otherwise NULL_TREE. If the current
3819 contour is left via an exception, then __sjthrow will pop the top
3820 element off the dynamic handler chain. The code that avoids doing
3821 the action we push into the handler chain in the exceptional case
3822 is contained in expand_cleanups.
3824 This routine is only used by expand_eh_region_start, and that is
3825 the only way in which an exception region should be started. This
3826 routine is only used when using the setjmp/longjmp codegen method
3827 for exception handling. */
3830 expand_dhc_cleanup (decl)
3833 struct nesting *thisblock = block_stack;
3836 /* Error if we are not in any block. */
3840 /* Record the cleanup for the dynamic handler chain. */
3842 /* All cleanups must be on the function_obstack. */
3843 push_obstacks_nochange ();
3844 resume_temporary_allocation ();
3845 cleanup = make_node (POPDHC_EXPR);
3848 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
3849 thisblock->data.block.cleanups
3850 = temp_tree_cons (decl, cleanup, thisblock->data.block.cleanups);
3852 /* If this block has a cleanup, it belongs in stack_block_stack. */
3853 stack_block_stack = thisblock;
3857 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3858 DECL_ELTS is the list of elements that belong to DECL's type.
3859 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3862 expand_anon_union_decl (decl, cleanup, decl_elts)
3863 tree decl, cleanup, decl_elts;
3865 struct nesting *thisblock = block_stack;
3869 expand_decl_cleanup (decl, cleanup);
3870 x = DECL_RTL (decl);
3874 tree decl_elt = TREE_VALUE (decl_elts);
3875 tree cleanup_elt = TREE_PURPOSE (decl_elts);
3876 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
3878 /* Propagate the union's alignment to the elements. */
3879 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
3881 /* If the element has BLKmode and the union doesn't, the union is
3882 aligned such that the element doesn't need to have BLKmode, so
3883 change the element's mode to the appropriate one for its size. */
3884 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
3885 DECL_MODE (decl_elt) = mode
3886 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt)),
3889 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3890 instead create a new MEM rtx with the proper mode. */
3891 if (GET_CODE (x) == MEM)
3893 if (mode == GET_MODE (x))
3894 DECL_RTL (decl_elt) = x;
3897 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
3898 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
3899 RTX_UNCHANGING_P (DECL_RTL (decl_elt)) = RTX_UNCHANGING_P (x);
3902 else if (GET_CODE (x) == REG)
3904 if (mode == GET_MODE (x))
3905 DECL_RTL (decl_elt) = x;
3907 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
3912 /* Record the cleanup if there is one. */
3915 thisblock->data.block.cleanups
3916 = temp_tree_cons (decl_elt, cleanup_elt,
3917 thisblock->data.block.cleanups);
3919 decl_elts = TREE_CHAIN (decl_elts);
3923 /* Expand a list of cleanups LIST.
3924 Elements may be expressions or may be nested lists.
3926 If DONT_DO is nonnull, then any list-element
3927 whose TREE_PURPOSE matches DONT_DO is omitted.
3928 This is sometimes used to avoid a cleanup associated with
3929 a value that is being returned out of the scope.
3931 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3932 goto and handle protection regions specially in that case.
3934 If REACHABLE, we emit code, otherwise just inform the exception handling
3935 code about this finalization. */
3938 expand_cleanups (list, dont_do, in_fixup, reachable)
3945 for (tail = list; tail; tail = TREE_CHAIN (tail))
3946 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
3948 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
3949 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
3954 tree cleanup = TREE_VALUE (tail);
3956 /* See expand_d{h,c}c_cleanup for why we avoid this. */
3957 if (TREE_CODE (cleanup) != POPDHC_EXPR
3958 && TREE_CODE (cleanup) != POPDCC_EXPR
3959 /* See expand_eh_region_start_tree for this case. */
3960 && ! TREE_ADDRESSABLE (tail))
3962 cleanup = protect_with_terminate (cleanup);
3963 expand_eh_region_end (cleanup);
3969 /* Cleanups may be run multiple times. For example,
3970 when exiting a binding contour, we expand the
3971 cleanups associated with that contour. When a goto
3972 within that binding contour has a target outside that
3973 contour, it will expand all cleanups from its scope to
3974 the target. Though the cleanups are expanded multiple
3975 times, the control paths are non-overlapping so the
3976 cleanups will not be executed twice. */
3978 /* We may need to protect fixups with rethrow regions. */
3979 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
3982 expand_fixup_region_start ();
3984 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
3986 expand_fixup_region_end (TREE_VALUE (tail));
3993 /* Mark when the context we are emitting RTL for as a conditional
3994 context, so that any cleanup actions we register with
3995 expand_decl_init will be properly conditionalized when those
3996 cleanup actions are later performed. Must be called before any
3997 expression (tree) is expanded that is within a conditional context. */
4000 start_cleanup_deferral ()
4002 /* block_stack can be NULL if we are inside the parameter list. It is
4003 OK to do nothing, because cleanups aren't possible here. */
4005 ++block_stack->data.block.conditional_code;
4008 /* Mark the end of a conditional region of code. Because cleanup
4009 deferrals may be nested, we may still be in a conditional region
4010 after we end the currently deferred cleanups, only after we end all
4011 deferred cleanups, are we back in unconditional code. */
4014 end_cleanup_deferral ()
4016 /* block_stack can be NULL if we are inside the parameter list. It is
4017 OK to do nothing, because cleanups aren't possible here. */
4019 --block_stack->data.block.conditional_code;
4022 /* Move all cleanups from the current block_stack
4023 to the containing block_stack, where they are assumed to
4024 have been created. If anything can cause a temporary to
4025 be created, but not expanded for more than one level of
4026 block_stacks, then this code will have to change. */
4031 struct nesting *block = block_stack;
4032 struct nesting *outer = block->next;
4034 outer->data.block.cleanups
4035 = chainon (block->data.block.cleanups,
4036 outer->data.block.cleanups);
4037 block->data.block.cleanups = 0;
4041 last_cleanup_this_contour ()
4043 if (block_stack == 0)
4046 return block_stack->data.block.cleanups;
4049 /* Return 1 if there are any pending cleanups at this point.
4050 If THIS_CONTOUR is nonzero, check the current contour as well.
4051 Otherwise, look only at the contours that enclose this one. */
4054 any_pending_cleanups (this_contour)
4057 struct nesting *block;
4059 if (block_stack == 0)
4062 if (this_contour && block_stack->data.block.cleanups != NULL)
4064 if (block_stack->data.block.cleanups == 0
4065 && block_stack->data.block.outer_cleanups == 0)
4068 for (block = block_stack->next; block; block = block->next)
4069 if (block->data.block.cleanups != 0)
4075 /* Enter a case (Pascal) or switch (C) statement.
4076 Push a block onto case_stack and nesting_stack
4077 to accumulate the case-labels that are seen
4078 and to record the labels generated for the statement.
4080 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4081 Otherwise, this construct is transparent for `exit_something'.
4083 EXPR is the index-expression to be dispatched on.
4084 TYPE is its nominal type. We could simply convert EXPR to this type,
4085 but instead we take short cuts. */
4088 expand_start_case (exit_flag, expr, type, printname)
4094 register struct nesting *thiscase = ALLOC_NESTING ();
4096 /* Make an entry on case_stack for the case we are entering. */
4098 thiscase->next = case_stack;
4099 thiscase->all = nesting_stack;
4100 thiscase->depth = ++nesting_depth;
4101 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4102 thiscase->data.case_stmt.case_list = 0;
4103 thiscase->data.case_stmt.index_expr = expr;
4104 thiscase->data.case_stmt.nominal_type = type;
4105 thiscase->data.case_stmt.default_label = 0;
4106 thiscase->data.case_stmt.num_ranges = 0;
4107 thiscase->data.case_stmt.printname = printname;
4108 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4109 case_stack = thiscase;
4110 nesting_stack = thiscase;
4112 do_pending_stack_adjust ();
4114 /* Make sure case_stmt.start points to something that won't
4115 need any transformation before expand_end_case. */
4116 if (GET_CODE (get_last_insn ()) != NOTE)
4117 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4119 thiscase->data.case_stmt.start = get_last_insn ();
4121 start_cleanup_deferral ();
4125 /* Start a "dummy case statement" within which case labels are invalid
4126 and are not connected to any larger real case statement.
4127 This can be used if you don't want to let a case statement jump
4128 into the middle of certain kinds of constructs. */
4131 expand_start_case_dummy ()
4133 register struct nesting *thiscase = ALLOC_NESTING ();
4135 /* Make an entry on case_stack for the dummy. */
4137 thiscase->next = case_stack;
4138 thiscase->all = nesting_stack;
4139 thiscase->depth = ++nesting_depth;
4140 thiscase->exit_label = 0;
4141 thiscase->data.case_stmt.case_list = 0;
4142 thiscase->data.case_stmt.start = 0;
4143 thiscase->data.case_stmt.nominal_type = 0;
4144 thiscase->data.case_stmt.default_label = 0;
4145 thiscase->data.case_stmt.num_ranges = 0;
4146 case_stack = thiscase;
4147 nesting_stack = thiscase;
4148 start_cleanup_deferral ();
4151 /* End a dummy case statement. */
4154 expand_end_case_dummy ()
4156 end_cleanup_deferral ();
4157 POPSTACK (case_stack);
4160 /* Return the data type of the index-expression
4161 of the innermost case statement, or null if none. */
4164 case_index_expr_type ()
4167 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4174 /* If this is the first label, warn if any insns have been emitted. */
4175 if (case_stack->data.case_stmt.line_number_status >= 0)
4179 restore_line_number_status
4180 (case_stack->data.case_stmt.line_number_status);
4181 case_stack->data.case_stmt.line_number_status = -1;
4183 for (insn = case_stack->data.case_stmt.start;
4185 insn = NEXT_INSN (insn))
4187 if (GET_CODE (insn) == CODE_LABEL)
4189 if (GET_CODE (insn) != NOTE
4190 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4193 insn = PREV_INSN (insn);
4194 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4196 /* If insn is zero, then there must have been a syntax error. */
4198 warning_with_file_and_line (NOTE_SOURCE_FILE(insn),
4199 NOTE_LINE_NUMBER(insn),
4200 "unreachable code at beginning of %s",
4201 case_stack->data.case_stmt.printname);
4208 /* Accumulate one case or default label inside a case or switch statement.
4209 VALUE is the value of the case (a null pointer, for a default label).
4210 The function CONVERTER, when applied to arguments T and V,
4211 converts the value V to the type T.
4213 If not currently inside a case or switch statement, return 1 and do
4214 nothing. The caller will print a language-specific error message.
4215 If VALUE is a duplicate or overlaps, return 2 and do nothing
4216 except store the (first) duplicate node in *DUPLICATE.
4217 If VALUE is out of range, return 3 and do nothing.
4218 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4219 Return 0 on success.
4221 Extended to handle range statements. */
4224 pushcase (value, converter, label, duplicate)
4225 register tree value;
4226 tree (*converter) PROTO((tree, tree));
4227 register tree label;
4233 /* Fail if not inside a real case statement. */
4234 if (! (case_stack && case_stack->data.case_stmt.start))
4237 if (stack_block_stack
4238 && stack_block_stack->depth > case_stack->depth)
4241 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4242 nominal_type = case_stack->data.case_stmt.nominal_type;
4244 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4245 if (index_type == error_mark_node)
4248 /* Convert VALUE to the type in which the comparisons are nominally done. */
4250 value = (*converter) (nominal_type, value);
4254 /* Fail if this value is out of range for the actual type of the index
4255 (which may be narrower than NOMINAL_TYPE). */
4256 if (value != 0 && ! int_fits_type_p (value, index_type))
4259 /* Fail if this is a duplicate or overlaps another entry. */
4262 if (case_stack->data.case_stmt.default_label != 0)
4264 *duplicate = case_stack->data.case_stmt.default_label;
4267 case_stack->data.case_stmt.default_label = label;
4270 return add_case_node (value, value, label, duplicate);
4272 expand_label (label);
4276 /* Like pushcase but this case applies to all values between VALUE1 and
4277 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4278 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4279 starts at VALUE1 and ends at the highest value of the index type.
4280 If both are NULL, this case applies to all values.
4282 The return value is the same as that of pushcase but there is one
4283 additional error code: 4 means the specified range was empty. */
4286 pushcase_range (value1, value2, converter, label, duplicate)
4287 register tree value1, value2;
4288 tree (*converter) PROTO((tree, tree));
4289 register tree label;
4295 /* Fail if not inside a real case statement. */
4296 if (! (case_stack && case_stack->data.case_stmt.start))
4299 if (stack_block_stack
4300 && stack_block_stack->depth > case_stack->depth)
4303 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4304 nominal_type = case_stack->data.case_stmt.nominal_type;
4306 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4307 if (index_type == error_mark_node)
4312 /* Convert VALUEs to type in which the comparisons are nominally done
4313 and replace any unspecified value with the corresponding bound. */
4315 value1 = TYPE_MIN_VALUE (index_type);
4317 value2 = TYPE_MAX_VALUE (index_type);
4319 /* Fail if the range is empty. Do this before any conversion since
4320 we want to allow out-of-range empty ranges. */
4321 if (value2 && tree_int_cst_lt (value2, value1))
4324 value1 = (*converter) (nominal_type, value1);
4326 /* If the max was unbounded, use the max of the nominal_type we are
4327 converting to. Do this after the < check above to suppress false
4330 value2 = TYPE_MAX_VALUE (nominal_type);
4331 value2 = (*converter) (nominal_type, value2);
4333 /* Fail if these values are out of range. */
4334 if (TREE_CONSTANT_OVERFLOW (value1)
4335 || ! int_fits_type_p (value1, index_type))
4338 if (TREE_CONSTANT_OVERFLOW (value2)
4339 || ! int_fits_type_p (value2, index_type))
4342 return add_case_node (value1, value2, label, duplicate);
4345 /* Do the actual insertion of a case label for pushcase and pushcase_range
4346 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4347 slowdown for large switch statements. */
4350 add_case_node (low, high, label, duplicate)
4355 struct case_node *p, **q, *r;
4357 q = &case_stack->data.case_stmt.case_list;
4364 /* Keep going past elements distinctly greater than HIGH. */
4365 if (tree_int_cst_lt (high, p->low))
4368 /* or distinctly less than LOW. */
4369 else if (tree_int_cst_lt (p->high, low))
4374 /* We have an overlap; this is an error. */
4375 *duplicate = p->code_label;
4380 /* Add this label to the chain, and succeed.
4381 Copy LOW, HIGH so they are on temporary rather than momentary
4382 obstack and will thus survive till the end of the case statement. */
4384 r = (struct case_node *) oballoc (sizeof (struct case_node));
4385 r->low = copy_node (low);
4387 /* If the bounds are equal, turn this into the one-value case. */
4389 if (tree_int_cst_equal (low, high))
4393 r->high = copy_node (high);
4394 case_stack->data.case_stmt.num_ranges++;
4397 r->code_label = label;
4398 expand_label (label);
4408 struct case_node *s;
4414 if (! (b = p->balance))
4415 /* Growth propagation from left side. */
4422 if ((p->left = s = r->right))
4431 if ((r->parent = s))
4439 case_stack->data.case_stmt.case_list = r;
4442 /* r->balance == +1 */
4447 struct case_node *t = r->right;
4449 if ((p->left = s = t->right))
4453 if ((r->right = s = t->left))
4467 if ((t->parent = s))
4475 case_stack->data.case_stmt.case_list = t;
4482 /* p->balance == +1; growth of left side balances the node. */
4492 if (! (b = p->balance))
4493 /* Growth propagation from right side. */
4501 if ((p->right = s = r->left))
4509 if ((r->parent = s))
4518 case_stack->data.case_stmt.case_list = r;
4522 /* r->balance == -1 */
4526 struct case_node *t = r->left;
4528 if ((p->right = s = t->left))
4533 if ((r->left = s = t->right))
4547 if ((t->parent = s))
4556 case_stack->data.case_stmt.case_list = t;
4562 /* p->balance == -1; growth of right side balances the node. */
4576 /* Returns the number of possible values of TYPE.
4577 Returns -1 if the number is unknown or variable.
4578 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4579 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4580 do not increase monotonically (there may be duplicates);
4581 to 1 if the values increase monotonically, but not always by 1;
4582 otherwise sets it to 0. */
4585 all_cases_count (type, spareness)
4589 HOST_WIDE_INT count;
4592 switch (TREE_CODE (type))
4599 count = 1 << BITS_PER_UNIT;
4603 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4604 || TYPE_MAX_VALUE (type) == NULL
4605 || TREE_CODE (TYPE_MAX_VALUE (type)) != INTEGER_CST)
4610 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4611 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4612 but with overflow checking. */
4613 tree mint = TYPE_MIN_VALUE (type);
4614 tree maxt = TYPE_MAX_VALUE (type);
4615 HOST_WIDE_INT lo, hi;
4616 neg_double(TREE_INT_CST_LOW (mint), TREE_INT_CST_HIGH (mint),
4618 add_double(TREE_INT_CST_LOW (maxt), TREE_INT_CST_HIGH (maxt),
4620 add_double (lo, hi, 1, 0, &lo, &hi);
4621 if (hi != 0 || lo < 0)
4628 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4630 if (TREE_CODE (TYPE_MIN_VALUE (type)) != INTEGER_CST
4631 || TREE_CODE (TREE_VALUE (t)) != INTEGER_CST
4632 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + count
4633 != TREE_INT_CST_LOW (TREE_VALUE (t)))
4637 if (*spareness == 1)
4639 tree prev = TREE_VALUE (TYPE_VALUES (type));
4640 for (t = TYPE_VALUES (type); t = TREE_CHAIN (t), t != NULL_TREE; )
4642 if (! tree_int_cst_lt (prev, TREE_VALUE (t)))
4647 prev = TREE_VALUE (t);
4656 #define BITARRAY_TEST(ARRAY, INDEX) \
4657 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4658 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4659 #define BITARRAY_SET(ARRAY, INDEX) \
4660 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4661 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4663 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4664 with the case values we have seen, assuming the case expression
4666 SPARSENESS is as determined by all_cases_count.
4668 The time needed is proportional to COUNT, unless
4669 SPARSENESS is 2, in which case quadratic time is needed. */
4672 mark_seen_cases (type, cases_seen, count, sparseness)
4674 unsigned char *cases_seen;
4678 tree next_node_to_try = NULL_TREE;
4679 long next_node_offset = 0;
4681 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
4682 tree val = make_node (INTEGER_CST);
4683 TREE_TYPE (val) = type;
4686 else if (sparseness == 2)
4691 /* This less efficient loop is only needed to handle
4692 duplicate case values (multiple enum constants
4693 with the same value). */
4694 TREE_TYPE (val) = TREE_TYPE (root->low);
4695 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
4696 t = TREE_CHAIN (t), xlo++)
4698 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
4699 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
4703 /* Keep going past elements distinctly greater than VAL. */
4704 if (tree_int_cst_lt (val, n->low))
4707 /* or distinctly less than VAL. */
4708 else if (tree_int_cst_lt (n->high, val))
4713 /* We have found a matching range. */
4714 BITARRAY_SET (cases_seen, xlo);
4724 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
4725 for (n = root; n; n = n->right)
4727 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
4728 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
4729 while ( ! tree_int_cst_lt (n->high, val))
4731 /* Calculate (into xlo) the "offset" of the integer (val).
4732 The element with lowest value has offset 0, the next smallest
4733 element has offset 1, etc. */
4735 HOST_WIDE_INT xlo, xhi;
4737 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
4739 /* The TYPE_VALUES will be in increasing order, so
4740 starting searching where we last ended. */
4741 t = next_node_to_try;
4742 xlo = next_node_offset;
4748 t = TYPE_VALUES (type);
4751 if (tree_int_cst_equal (val, TREE_VALUE (t)))
4753 next_node_to_try = TREE_CHAIN (t);
4754 next_node_offset = xlo + 1;
4759 if (t == next_node_to_try)
4768 t = TYPE_MIN_VALUE (type);
4770 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
4774 add_double (xlo, xhi,
4775 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4779 if (xhi == 0 && xlo >= 0 && xlo < count)
4780 BITARRAY_SET (cases_seen, xlo);
4781 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
4783 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
4789 /* Called when the index of a switch statement is an enumerated type
4790 and there is no default label.
4792 Checks that all enumeration literals are covered by the case
4793 expressions of a switch. Also, warn if there are any extra
4794 switch cases that are *not* elements of the enumerated type.
4796 If all enumeration literals were covered by the case expressions,
4797 turn one of the expressions into the default expression since it should
4798 not be possible to fall through such a switch. */
4801 check_for_full_enumeration_handling (type)
4804 register struct case_node *n;
4805 register tree chain;
4806 #if 0 /* variable used by 'if 0'ed code below. */
4807 register struct case_node **l;
4811 /* True iff the selector type is a numbered set mode. */
4814 /* The number of possible selector values. */
4817 /* For each possible selector value. a one iff it has been matched
4818 by a case value alternative. */
4819 unsigned char *cases_seen;
4821 /* The allocated size of cases_seen, in chars. */
4827 size = all_cases_count (type, &sparseness);
4828 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
4830 if (size > 0 && size < 600000
4831 /* We deliberately use malloc here - not xmalloc. */
4832 && (cases_seen = (unsigned char *) malloc (bytes_needed)) != NULL)
4835 tree v = TYPE_VALUES (type);
4836 bzero (cases_seen, bytes_needed);
4838 /* The time complexity of this code is normally O(N), where
4839 N being the number of members in the enumerated type.
4840 However, if type is a ENUMERAL_TYPE whose values do not
4841 increase monotonically, O(N*log(N)) time may be needed. */
4843 mark_seen_cases (type, cases_seen, size, sparseness);
4845 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
4847 if (BITARRAY_TEST(cases_seen, i) == 0)
4848 warning ("enumeration value `%s' not handled in switch",
4849 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
4855 /* Now we go the other way around; we warn if there are case
4856 expressions that don't correspond to enumerators. This can
4857 occur since C and C++ don't enforce type-checking of
4858 assignments to enumeration variables. */
4860 if (case_stack->data.case_stmt.case_list
4861 && case_stack->data.case_stmt.case_list->left)
4862 case_stack->data.case_stmt.case_list
4863 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
4865 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
4867 for (chain = TYPE_VALUES (type);
4868 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
4869 chain = TREE_CHAIN (chain))
4874 if (TYPE_NAME (type) == 0)
4875 warning ("case value `%ld' not in enumerated type",
4876 (long) TREE_INT_CST_LOW (n->low));
4878 warning ("case value `%ld' not in enumerated type `%s'",
4879 (long) TREE_INT_CST_LOW (n->low),
4880 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4883 : DECL_NAME (TYPE_NAME (type))));
4885 if (!tree_int_cst_equal (n->low, n->high))
4887 for (chain = TYPE_VALUES (type);
4888 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
4889 chain = TREE_CHAIN (chain))
4894 if (TYPE_NAME (type) == 0)
4895 warning ("case value `%ld' not in enumerated type",
4896 (long) TREE_INT_CST_LOW (n->high));
4898 warning ("case value `%ld' not in enumerated type `%s'",
4899 (long) TREE_INT_CST_LOW (n->high),
4900 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
4903 : DECL_NAME (TYPE_NAME (type))));
4909 /* ??? This optimization is disabled because it causes valid programs to
4910 fail. ANSI C does not guarantee that an expression with enum type
4911 will have a value that is the same as one of the enumeration literals. */
4913 /* If all values were found as case labels, make one of them the default
4914 label. Thus, this switch will never fall through. We arbitrarily pick
4915 the last one to make the default since this is likely the most
4916 efficient choice. */
4920 for (l = &case_stack->data.case_stmt.case_list;
4925 case_stack->data.case_stmt.default_label = (*l)->code_label;
4932 /* Terminate a case (Pascal) or switch (C) statement
4933 in which ORIG_INDEX is the expression to be tested.
4934 Generate the code to test it and jump to the right place. */
4937 expand_end_case (orig_index)
4940 tree minval, maxval, range, orig_minval;
4941 rtx default_label = 0;
4942 register struct case_node *n;
4950 register struct nesting *thiscase = case_stack;
4951 tree index_expr, index_type;
4954 table_label = gen_label_rtx ();
4955 index_expr = thiscase->data.case_stmt.index_expr;
4956 index_type = TREE_TYPE (index_expr);
4957 unsignedp = TREE_UNSIGNED (index_type);
4959 do_pending_stack_adjust ();
4961 /* This might get an spurious warning in the presence of a syntax error;
4962 it could be fixed by moving the call to check_seenlabel after the
4963 check for error_mark_node, and copying the code of check_seenlabel that
4964 deals with case_stack->data.case_stmt.line_number_status /
4965 restore_line_number_status in front of the call to end_cleanup_deferral;
4966 However, this might miss some useful warnings in the presence of
4967 non-syntax errors. */
4970 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4971 if (index_type != error_mark_node)
4973 /* If switch expression was an enumerated type, check that all
4974 enumeration literals are covered by the cases.
4975 No sense trying this if there's a default case, however. */
4977 if (!thiscase->data.case_stmt.default_label
4978 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
4979 && TREE_CODE (index_expr) != INTEGER_CST)
4980 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
4982 /* If we don't have a default-label, create one here,
4983 after the body of the switch. */
4984 if (thiscase->data.case_stmt.default_label == 0)
4986 thiscase->data.case_stmt.default_label
4987 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
4988 expand_label (thiscase->data.case_stmt.default_label);
4990 default_label = label_rtx (thiscase->data.case_stmt.default_label);
4992 before_case = get_last_insn ();
4994 if (thiscase->data.case_stmt.case_list
4995 && thiscase->data.case_stmt.case_list->left)
4996 thiscase->data.case_stmt.case_list
4997 = case_tree2list(thiscase->data.case_stmt.case_list, 0);
4999 /* Simplify the case-list before we count it. */
5000 group_case_nodes (thiscase->data.case_stmt.case_list);
5002 /* Get upper and lower bounds of case values.
5003 Also convert all the case values to the index expr's data type. */
5006 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5008 /* Check low and high label values are integers. */
5009 if (TREE_CODE (n->low) != INTEGER_CST)
5011 if (TREE_CODE (n->high) != INTEGER_CST)
5014 n->low = convert (index_type, n->low);
5015 n->high = convert (index_type, n->high);
5017 /* Count the elements and track the largest and smallest
5018 of them (treating them as signed even if they are not). */
5026 if (INT_CST_LT (n->low, minval))
5028 if (INT_CST_LT (maxval, n->high))
5031 /* A range counts double, since it requires two compares. */
5032 if (! tree_int_cst_equal (n->low, n->high))
5036 orig_minval = minval;
5038 /* Compute span of values. */
5040 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5042 end_cleanup_deferral ();
5046 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5048 emit_jump (default_label);
5051 /* If range of values is much bigger than number of values,
5052 make a sequence of conditional branches instead of a dispatch.
5053 If the switch-index is a constant, do it this way
5054 because we can optimize it. */
5056 #ifndef CASE_VALUES_THRESHOLD
5058 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5060 /* If machine does not have a case insn that compares the
5061 bounds, this means extra overhead for dispatch tables
5062 which raises the threshold for using them. */
5063 #define CASE_VALUES_THRESHOLD 5
5064 #endif /* HAVE_casesi */
5065 #endif /* CASE_VALUES_THRESHOLD */
5067 else if (TREE_INT_CST_HIGH (range) != 0
5068 || count < (unsigned int) CASE_VALUES_THRESHOLD
5069 || ((unsigned HOST_WIDE_INT) (TREE_INT_CST_LOW (range))
5071 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5074 || TREE_CODE (index_expr) == INTEGER_CST
5075 /* These will reduce to a constant. */
5076 || (TREE_CODE (index_expr) == CALL_EXPR
5077 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5078 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5079 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5080 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5081 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5083 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5085 /* If the index is a short or char that we do not have
5086 an insn to handle comparisons directly, convert it to
5087 a full integer now, rather than letting each comparison
5088 generate the conversion. */
5090 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5091 && (cmp_optab->handlers[(int) GET_MODE(index)].insn_code
5092 == CODE_FOR_nothing))
5094 enum machine_mode wider_mode;
5095 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5096 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5097 if (cmp_optab->handlers[(int) wider_mode].insn_code
5098 != CODE_FOR_nothing)
5100 index = convert_to_mode (wider_mode, index, unsignedp);
5106 do_pending_stack_adjust ();
5108 index = protect_from_queue (index, 0);
5109 if (GET_CODE (index) == MEM)
5110 index = copy_to_reg (index);
5111 if (GET_CODE (index) == CONST_INT
5112 || TREE_CODE (index_expr) == INTEGER_CST)
5114 /* Make a tree node with the proper constant value
5115 if we don't already have one. */
5116 if (TREE_CODE (index_expr) != INTEGER_CST)
5119 = build_int_2 (INTVAL (index),
5120 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5121 index_expr = convert (index_type, index_expr);
5124 /* For constant index expressions we need only
5125 issue a unconditional branch to the appropriate
5126 target code. The job of removing any unreachable
5127 code is left to the optimisation phase if the
5128 "-O" option is specified. */
5129 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5130 if (! tree_int_cst_lt (index_expr, n->low)
5131 && ! tree_int_cst_lt (n->high, index_expr))
5135 emit_jump (label_rtx (n->code_label));
5137 emit_jump (default_label);
5141 /* If the index expression is not constant we generate
5142 a binary decision tree to select the appropriate
5143 target code. This is done as follows:
5145 The list of cases is rearranged into a binary tree,
5146 nearly optimal assuming equal probability for each case.
5148 The tree is transformed into RTL, eliminating
5149 redundant test conditions at the same time.
5151 If program flow could reach the end of the
5152 decision tree an unconditional jump to the
5153 default code is emitted. */
5156 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5157 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5158 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5160 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5161 default_label, index_type);
5162 emit_jump_if_reachable (default_label);
5171 enum machine_mode index_mode = SImode;
5172 int index_bits = GET_MODE_BITSIZE (index_mode);
5174 enum machine_mode op_mode;
5176 /* Convert the index to SImode. */
5177 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5178 > GET_MODE_BITSIZE (index_mode))
5180 enum machine_mode omode = TYPE_MODE (index_type);
5181 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5183 /* We must handle the endpoints in the original mode. */
5184 index_expr = build (MINUS_EXPR, index_type,
5185 index_expr, minval);
5186 minval = integer_zero_node;
5187 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5188 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5189 omode, 1, 0, default_label);
5190 /* Now we can safely truncate. */
5191 index = convert_to_mode (index_mode, index, 0);
5195 if (TYPE_MODE (index_type) != index_mode)
5197 index_expr = convert (type_for_size (index_bits, 0),
5199 index_type = TREE_TYPE (index_expr);
5202 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5205 index = protect_from_queue (index, 0);
5206 do_pending_stack_adjust ();
5208 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][0];
5209 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][0])
5211 index = copy_to_mode_reg (op_mode, index);
5213 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5215 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][1];
5216 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][1])
5218 op1 = copy_to_mode_reg (op_mode, op1);
5220 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5222 op_mode = insn_operand_mode[(int)CODE_FOR_casesi][2];
5223 if (! (*insn_operand_predicate[(int)CODE_FOR_casesi][2])
5225 op2 = copy_to_mode_reg (op_mode, op2);
5227 emit_jump_insn (gen_casesi (index, op1, op2,
5228 table_label, default_label));
5232 #ifdef HAVE_tablejump
5233 if (! win && HAVE_tablejump)
5235 index_expr = convert (thiscase->data.case_stmt.nominal_type,
5236 fold (build (MINUS_EXPR, index_type,
5237 index_expr, minval)));
5238 index_type = TREE_TYPE (index_expr);
5239 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5241 index = protect_from_queue (index, 0);
5242 do_pending_stack_adjust ();
5244 do_tablejump (index, TYPE_MODE (index_type),
5245 expand_expr (range, NULL_RTX, VOIDmode, 0),
5246 table_label, default_label);
5253 /* Get table of labels to jump to, in order of case index. */
5255 ncases = TREE_INT_CST_LOW (range) + 1;
5256 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5257 bzero ((char *) labelvec, ncases * sizeof (rtx));
5259 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5261 register HOST_WIDE_INT i
5262 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5267 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5268 if (i + TREE_INT_CST_LOW (orig_minval)
5269 == TREE_INT_CST_LOW (n->high))
5275 /* Fill in the gaps with the default. */
5276 for (i = 0; i < ncases; i++)
5277 if (labelvec[i] == 0)
5278 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5280 /* Output the table */
5281 emit_label (table_label);
5283 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5284 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5285 gen_rtx_LABEL_REF (Pmode, table_label),
5286 gen_rtvec_v (ncases, labelvec),
5287 const0_rtx, const0_rtx, 0));
5289 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5290 gen_rtvec_v (ncases, labelvec)));
5292 /* If the case insn drops through the table,
5293 after the table we must jump to the default-label.
5294 Otherwise record no drop-through after the table. */
5295 #ifdef CASE_DROPS_THROUGH
5296 emit_jump (default_label);
5302 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5303 reorder_insns (before_case, get_last_insn (),
5304 thiscase->data.case_stmt.start);
5307 end_cleanup_deferral ();
5309 if (thiscase->exit_label)
5310 emit_label (thiscase->exit_label);
5312 POPSTACK (case_stack);
5317 /* Convert the tree NODE into a list linked by the right field, with the left
5318 field zeroed. RIGHT is used for recursion; it is a list to be placed
5319 rightmost in the resulting list. */
5321 static struct case_node *
5322 case_tree2list (node, right)
5323 struct case_node *node, *right;
5325 struct case_node *left;
5328 right = case_tree2list (node->right, right);
5330 node->right = right;
5331 if ((left = node->left))
5334 return case_tree2list (left, node);
5340 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5343 do_jump_if_equal (op1, op2, label, unsignedp)
5344 rtx op1, op2, label;
5347 if (GET_CODE (op1) == CONST_INT
5348 && GET_CODE (op2) == CONST_INT)
5350 if (INTVAL (op1) == INTVAL (op2))
5355 enum machine_mode mode = GET_MODE (op1);
5356 if (mode == VOIDmode)
5357 mode = GET_MODE (op2);
5358 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5363 /* Not all case values are encountered equally. This function
5364 uses a heuristic to weight case labels, in cases where that
5365 looks like a reasonable thing to do.
5367 Right now, all we try to guess is text, and we establish the
5370 chars above space: 16
5379 If we find any cases in the switch that are not either -1 or in the range
5380 of valid ASCII characters, or are control characters other than those
5381 commonly used with "\", don't treat this switch scanning text.
5383 Return 1 if these nodes are suitable for cost estimation, otherwise
5387 estimate_case_costs (node)
5390 tree min_ascii = build_int_2 (-1, -1);
5391 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5395 /* If we haven't already made the cost table, make it now. Note that the
5396 lower bound of the table is -1, not zero. */
5398 if (cost_table == NULL)
5400 cost_table = ((short *) xmalloc (129 * sizeof (short))) + 1;
5401 bzero ((char *) (cost_table - 1), 129 * sizeof (short));
5403 for (i = 0; i < 128; i++)
5407 else if (ISPUNCT (i))
5409 else if (ISCNTRL (i))
5413 cost_table[' '] = 8;
5414 cost_table['\t'] = 4;
5415 cost_table['\0'] = 4;
5416 cost_table['\n'] = 2;
5417 cost_table['\f'] = 1;
5418 cost_table['\v'] = 1;
5419 cost_table['\b'] = 1;
5422 /* See if all the case expressions look like text. It is text if the
5423 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5424 as signed arithmetic since we don't want to ever access cost_table with a
5425 value less than -1. Also check that none of the constants in a range
5426 are strange control characters. */
5428 for (n = node; n; n = n->right)
5430 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5433 for (i = TREE_INT_CST_LOW (n->low); i <= TREE_INT_CST_LOW (n->high); i++)
5434 if (cost_table[i] < 0)
5438 /* All interesting values are within the range of interesting
5439 ASCII characters. */
5443 /* Scan an ordered list of case nodes
5444 combining those with consecutive values or ranges.
5446 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5449 group_case_nodes (head)
5452 case_node_ptr node = head;
5456 rtx lb = next_real_insn (label_rtx (node->code_label));
5458 case_node_ptr np = node;
5460 /* Try to group the successors of NODE with NODE. */
5461 while (((np = np->right) != 0)
5462 /* Do they jump to the same place? */
5463 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5464 || (lb != 0 && lb2 != 0
5465 && simplejump_p (lb)
5466 && simplejump_p (lb2)
5467 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5468 SET_SRC (PATTERN (lb2)))))
5469 /* Are their ranges consecutive? */
5470 && tree_int_cst_equal (np->low,
5471 fold (build (PLUS_EXPR,
5472 TREE_TYPE (node->high),
5475 /* An overflow is not consecutive. */
5476 && tree_int_cst_lt (node->high,
5477 fold (build (PLUS_EXPR,
5478 TREE_TYPE (node->high),
5480 integer_one_node))))
5482 node->high = np->high;
5484 /* NP is the first node after NODE which can't be grouped with it.
5485 Delete the nodes in between, and move on to that node. */
5491 /* Take an ordered list of case nodes
5492 and transform them into a near optimal binary tree,
5493 on the assumption that any target code selection value is as
5494 likely as any other.
5496 The transformation is performed by splitting the ordered
5497 list into two equal sections plus a pivot. The parts are
5498 then attached to the pivot as left and right branches. Each
5499 branch is then transformed recursively. */
5502 balance_case_nodes (head, parent)
5503 case_node_ptr *head;
5504 case_node_ptr parent;
5506 register case_node_ptr np;
5514 register case_node_ptr *npp;
5517 /* Count the number of entries on branch. Also count the ranges. */
5521 if (!tree_int_cst_equal (np->low, np->high))
5525 cost += cost_table[TREE_INT_CST_LOW (np->high)];
5529 cost += cost_table[TREE_INT_CST_LOW (np->low)];
5537 /* Split this list if it is long enough for that to help. */
5542 /* Find the place in the list that bisects the list's total cost,
5543 Here I gets half the total cost. */
5548 /* Skip nodes while their cost does not reach that amount. */
5549 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5550 i -= cost_table[TREE_INT_CST_LOW ((*npp)->high)];
5551 i -= cost_table[TREE_INT_CST_LOW ((*npp)->low)];
5554 npp = &(*npp)->right;
5559 /* Leave this branch lopsided, but optimize left-hand
5560 side and fill in `parent' fields for right-hand side. */
5562 np->parent = parent;
5563 balance_case_nodes (&np->left, np);
5564 for (; np->right; np = np->right)
5565 np->right->parent = np;
5569 /* If there are just three nodes, split at the middle one. */
5571 npp = &(*npp)->right;
5574 /* Find the place in the list that bisects the list's total cost,
5575 where ranges count as 2.
5576 Here I gets half the total cost. */
5577 i = (i + ranges + 1) / 2;
5580 /* Skip nodes while their cost does not reach that amount. */
5581 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5586 npp = &(*npp)->right;
5591 np->parent = parent;
5594 /* Optimize each of the two split parts. */
5595 balance_case_nodes (&np->left, np);
5596 balance_case_nodes (&np->right, np);
5600 /* Else leave this branch as one level,
5601 but fill in `parent' fields. */
5603 np->parent = parent;
5604 for (; np->right; np = np->right)
5605 np->right->parent = np;
5610 /* Search the parent sections of the case node tree
5611 to see if a test for the lower bound of NODE would be redundant.
5612 INDEX_TYPE is the type of the index expression.
5614 The instructions to generate the case decision tree are
5615 output in the same order as nodes are processed so it is
5616 known that if a parent node checks the range of the current
5617 node minus one that the current node is bounded at its lower
5618 span. Thus the test would be redundant. */
5621 node_has_low_bound (node, index_type)
5626 case_node_ptr pnode;
5628 /* If the lower bound of this node is the lowest value in the index type,
5629 we need not test it. */
5631 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
5634 /* If this node has a left branch, the value at the left must be less
5635 than that at this node, so it cannot be bounded at the bottom and
5636 we need not bother testing any further. */
5641 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
5642 node->low, integer_one_node));
5644 /* If the subtraction above overflowed, we can't verify anything.
5645 Otherwise, look for a parent that tests our value - 1. */
5647 if (! tree_int_cst_lt (low_minus_one, node->low))
5650 for (pnode = node->parent; pnode; pnode = pnode->parent)
5651 if (tree_int_cst_equal (low_minus_one, pnode->high))
5657 /* Search the parent sections of the case node tree
5658 to see if a test for the upper bound of NODE would be redundant.
5659 INDEX_TYPE is the type of the index expression.
5661 The instructions to generate the case decision tree are
5662 output in the same order as nodes are processed so it is
5663 known that if a parent node checks the range of the current
5664 node plus one that the current node is bounded at its upper
5665 span. Thus the test would be redundant. */
5668 node_has_high_bound (node, index_type)
5673 case_node_ptr pnode;
5675 /* If there is no upper bound, obviously no test is needed. */
5677 if (TYPE_MAX_VALUE (index_type) == NULL)
5680 /* If the upper bound of this node is the highest value in the type
5681 of the index expression, we need not test against it. */
5683 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
5686 /* If this node has a right branch, the value at the right must be greater
5687 than that at this node, so it cannot be bounded at the top and
5688 we need not bother testing any further. */
5693 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
5694 node->high, integer_one_node));
5696 /* If the addition above overflowed, we can't verify anything.
5697 Otherwise, look for a parent that tests our value + 1. */
5699 if (! tree_int_cst_lt (node->high, high_plus_one))
5702 for (pnode = node->parent; pnode; pnode = pnode->parent)
5703 if (tree_int_cst_equal (high_plus_one, pnode->low))
5709 /* Search the parent sections of the
5710 case node tree to see if both tests for the upper and lower
5711 bounds of NODE would be redundant. */
5714 node_is_bounded (node, index_type)
5718 return (node_has_low_bound (node, index_type)
5719 && node_has_high_bound (node, index_type));
5722 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5725 emit_jump_if_reachable (label)
5728 if (GET_CODE (get_last_insn ()) != BARRIER)
5732 /* Emit step-by-step code to select a case for the value of INDEX.
5733 The thus generated decision tree follows the form of the
5734 case-node binary tree NODE, whose nodes represent test conditions.
5735 INDEX_TYPE is the type of the index of the switch.
5737 Care is taken to prune redundant tests from the decision tree
5738 by detecting any boundary conditions already checked by
5739 emitted rtx. (See node_has_high_bound, node_has_low_bound
5740 and node_is_bounded, above.)
5742 Where the test conditions can be shown to be redundant we emit
5743 an unconditional jump to the target code. As a further
5744 optimization, the subordinates of a tree node are examined to
5745 check for bounded nodes. In this case conditional and/or
5746 unconditional jumps as a result of the boundary check for the
5747 current node are arranged to target the subordinates associated
5748 code for out of bound conditions on the current node.
5750 We can assume that when control reaches the code generated here,
5751 the index value has already been compared with the parents
5752 of this node, and determined to be on the same side of each parent
5753 as this node is. Thus, if this node tests for the value 51,
5754 and a parent tested for 52, we don't need to consider
5755 the possibility of a value greater than 51. If another parent
5756 tests for the value 50, then this node need not test anything. */
5759 emit_case_nodes (index, node, default_label, index_type)
5765 /* If INDEX has an unsigned type, we must make unsigned branches. */
5766 int unsignedp = TREE_UNSIGNED (index_type);
5767 typedef rtx rtx_fn ();
5768 enum machine_mode mode = GET_MODE (index);
5770 /* See if our parents have already tested everything for us.
5771 If they have, emit an unconditional jump for this node. */
5772 if (node_is_bounded (node, index_type))
5773 emit_jump (label_rtx (node->code_label));
5775 else if (tree_int_cst_equal (node->low, node->high))
5777 /* Node is single valued. First see if the index expression matches
5778 this node and then check our children, if any. */
5780 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
5781 label_rtx (node->code_label), unsignedp);
5783 if (node->right != 0 && node->left != 0)
5785 /* This node has children on both sides.
5786 Dispatch to one side or the other
5787 by comparing the index value with this node's value.
5788 If one subtree is bounded, check that one first,
5789 so we can avoid real branches in the tree. */
5791 if (node_is_bounded (node->right, index_type))
5793 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
5795 GT, NULL_RTX, mode, unsignedp, 0,
5796 label_rtx (node->right->code_label));
5797 emit_case_nodes (index, node->left, default_label, index_type);
5800 else if (node_is_bounded (node->left, index_type))
5802 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
5804 LT, NULL_RTX, mode, unsignedp, 0,
5805 label_rtx (node->left->code_label));
5806 emit_case_nodes (index, node->right, default_label, index_type);
5811 /* Neither node is bounded. First distinguish the two sides;
5812 then emit the code for one side at a time. */
5815 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5817 /* See if the value is on the right. */
5818 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
5820 GT, NULL_RTX, mode, unsignedp, 0,
5821 label_rtx (test_label));
5823 /* Value must be on the left.
5824 Handle the left-hand subtree. */
5825 emit_case_nodes (index, node->left, default_label, index_type);
5826 /* If left-hand subtree does nothing,
5828 emit_jump_if_reachable (default_label);
5830 /* Code branches here for the right-hand subtree. */
5831 expand_label (test_label);
5832 emit_case_nodes (index, node->right, default_label, index_type);
5836 else if (node->right != 0 && node->left == 0)
5838 /* Here we have a right child but no left so we issue conditional
5839 branch to default and process the right child.
5841 Omit the conditional branch to default if we it avoid only one
5842 right child; it costs too much space to save so little time. */
5844 if (node->right->right || node->right->left
5845 || !tree_int_cst_equal (node->right->low, node->right->high))
5847 if (!node_has_low_bound (node, index_type))
5849 emit_cmp_and_jump_insns (index, expand_expr (node->high,
5852 LT, NULL_RTX, mode, unsignedp, 0,
5856 emit_case_nodes (index, node->right, default_label, index_type);
5859 /* We cannot process node->right normally
5860 since we haven't ruled out the numbers less than
5861 this node's value. So handle node->right explicitly. */
5862 do_jump_if_equal (index,
5863 expand_expr (node->right->low, NULL_RTX,
5865 label_rtx (node->right->code_label), unsignedp);
5868 else if (node->right == 0 && node->left != 0)
5870 /* Just one subtree, on the left. */
5872 #if 0 /* The following code and comment were formerly part
5873 of the condition here, but they didn't work
5874 and I don't understand what the idea was. -- rms. */
5875 /* If our "most probable entry" is less probable
5876 than the default label, emit a jump to
5877 the default label using condition codes
5878 already lying around. With no right branch,
5879 a branch-greater-than will get us to the default
5882 && cost_table[TREE_INT_CST_LOW (node->high)] < 12)
5885 if (node->left->left || node->left->right
5886 || !tree_int_cst_equal (node->left->low, node->left->high))
5888 if (!node_has_high_bound (node, index_type))
5890 emit_cmp_and_jump_insns (index, expand_expr (node->high,
5893 GT, NULL_RTX, mode, unsignedp, 0,
5897 emit_case_nodes (index, node->left, default_label, index_type);
5900 /* We cannot process node->left normally
5901 since we haven't ruled out the numbers less than
5902 this node's value. So handle node->left explicitly. */
5903 do_jump_if_equal (index,
5904 expand_expr (node->left->low, NULL_RTX,
5906 label_rtx (node->left->code_label), unsignedp);
5911 /* Node is a range. These cases are very similar to those for a single
5912 value, except that we do not start by testing whether this node
5913 is the one to branch to. */
5915 if (node->right != 0 && node->left != 0)
5917 /* Node has subtrees on both sides.
5918 If the right-hand subtree is bounded,
5919 test for it first, since we can go straight there.
5920 Otherwise, we need to make a branch in the control structure,
5921 then handle the two subtrees. */
5922 tree test_label = 0;
5925 if (node_is_bounded (node->right, index_type))
5926 /* Right hand node is fully bounded so we can eliminate any
5927 testing and branch directly to the target code. */
5928 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
5930 GT, NULL_RTX, mode, unsignedp, 0,
5931 label_rtx (node->right->code_label));
5934 /* Right hand node requires testing.
5935 Branch to a label where we will handle it later. */
5937 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5938 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
5940 GT, NULL_RTX, mode, unsignedp, 0,
5941 label_rtx (test_label));
5944 /* Value belongs to this node or to the left-hand subtree. */
5946 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
5948 GE, NULL_RTX, mode, unsignedp, 0,
5949 label_rtx (node->code_label));
5951 /* Handle the left-hand subtree. */
5952 emit_case_nodes (index, node->left, default_label, index_type);
5954 /* If right node had to be handled later, do that now. */
5958 /* If the left-hand subtree fell through,
5959 don't let it fall into the right-hand subtree. */
5960 emit_jump_if_reachable (default_label);
5962 expand_label (test_label);
5963 emit_case_nodes (index, node->right, default_label, index_type);
5967 else if (node->right != 0 && node->left == 0)
5969 /* Deal with values to the left of this node,
5970 if they are possible. */
5971 if (!node_has_low_bound (node, index_type))
5973 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
5975 LT, NULL_RTX, mode, unsignedp, 0,
5979 /* Value belongs to this node or to the right-hand subtree. */
5981 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
5983 LE, NULL_RTX, mode, unsignedp, 0,
5984 label_rtx (node->code_label));
5986 emit_case_nodes (index, node->right, default_label, index_type);
5989 else if (node->right == 0 && node->left != 0)
5991 /* Deal with values to the right of this node,
5992 if they are possible. */
5993 if (!node_has_high_bound (node, index_type))
5995 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
5997 GT, NULL_RTX, mode, unsignedp, 0,
6001 /* Value belongs to this node or to the left-hand subtree. */
6003 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6005 GE, NULL_RTX, mode, unsignedp, 0,
6006 label_rtx (node->code_label));
6008 emit_case_nodes (index, node->left, default_label, index_type);
6013 /* Node has no children so we check low and high bounds to remove
6014 redundant tests. Only one of the bounds can exist,
6015 since otherwise this node is bounded--a case tested already. */
6017 if (!node_has_high_bound (node, index_type))
6019 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6021 GT, NULL_RTX, mode, unsignedp, 0,
6025 if (!node_has_low_bound (node, index_type))
6027 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6029 LT, NULL_RTX, mode, unsignedp, 0,
6033 emit_jump (label_rtx (node->code_label));
6038 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6039 so that the debugging info will be correct for the unrolled loop. */
6041 /* Indexed by block number, contains a pointer to the N'th block node.
6043 Allocated by the call to identify_blocks, then released after the call
6044 to reorder_blocks in the function unroll_block_trees. */
6046 static tree *block_vector;
6049 find_loop_tree_blocks ()
6051 tree block = DECL_INITIAL (current_function_decl);
6053 block_vector = identify_blocks (block, get_insns ());
6057 unroll_block_trees ()
6059 tree block = DECL_INITIAL (current_function_decl);
6061 reorder_blocks (block_vector, block, get_insns ());
6063 /* Release any memory allocated by identify_blocks. */
6065 free (block_vector);