1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
45 #include "insn-flags.h"
46 #include "insn-config.h"
47 #include "insn-codes.h"
49 #include "hard-reg-set.h"
58 #define obstack_chunk_alloc xmalloc
59 #define obstack_chunk_free free
60 struct obstack stmt_obstack;
62 /* Assume that case vectors are not pc-relative. */
63 #ifndef CASE_VECTOR_PC_RELATIVE
64 #define CASE_VECTOR_PC_RELATIVE 0
67 /* Functions and data structures for expanding case statements. */
69 /* Case label structure, used to hold info on labels within case
70 statements. We handle "range" labels; for a single-value label
71 as in C, the high and low limits are the same.
73 An AVL tree of case nodes is initially created, and later transformed
74 to a list linked via the RIGHT fields in the nodes. Nodes with
75 higher case values are later in the list.
77 Switch statements can be output in one of two forms. A branch table
78 is used if there are more than a few labels and the labels are dense
79 within the range between the smallest and largest case value. If a
80 branch table is used, no further manipulations are done with the case
83 The alternative to the use of a branch table is to generate a series
84 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
85 and PARENT fields to hold a binary tree. Initially the tree is
86 totally unbalanced, with everything on the right. We balance the tree
87 with nodes on the left having lower case values than the parent
88 and nodes on the right having higher values. We then output the tree
93 struct case_node *left; /* Left son in binary tree */
94 struct case_node *right; /* Right son in binary tree; also node chain */
95 struct case_node *parent; /* Parent of node in binary tree */
96 tree low; /* Lowest index value for this label */
97 tree high; /* Highest index value for this label */
98 tree code_label; /* Label to jump to when node matches */
102 typedef struct case_node case_node;
103 typedef struct case_node *case_node_ptr;
105 /* These are used by estimate_case_costs and balance_case_nodes. */
107 /* This must be a signed type, and non-ANSI compilers lack signed char. */
108 static short cost_table_[129];
109 static int use_cost_table;
110 static int cost_table_initialized;
112 /* Special care is needed because we allow -1, but TREE_INT_CST_LOW
114 #define COST_TABLE(I) cost_table_[(unsigned HOST_WIDE_INT)((I) + 1)]
116 /* Stack of control and binding constructs we are currently inside.
118 These constructs begin when you call `expand_start_WHATEVER'
119 and end when you call `expand_end_WHATEVER'. This stack records
120 info about how the construct began that tells the end-function
121 what to do. It also may provide information about the construct
122 to alter the behavior of other constructs within the body.
123 For example, they may affect the behavior of C `break' and `continue'.
125 Each construct gets one `struct nesting' object.
126 All of these objects are chained through the `all' field.
127 `nesting_stack' points to the first object (innermost construct).
128 The position of an entry on `nesting_stack' is in its `depth' field.
130 Each type of construct has its own individual stack.
131 For example, loops have `loop_stack'. Each object points to the
132 next object of the same type through the `next' field.
134 Some constructs are visible to `break' exit-statements and others
135 are not. Which constructs are visible depends on the language.
136 Therefore, the data structure allows each construct to be visible
137 or not, according to the args given when the construct is started.
138 The construct is visible if the `exit_label' field is non-null.
139 In that case, the value should be a CODE_LABEL rtx. */
144 struct nesting *next;
149 /* For conds (if-then and if-then-else statements). */
152 /* Label for the end of the if construct.
153 There is none if EXITFLAG was not set
154 and no `else' has been seen yet. */
156 /* Label for the end of this alternative.
157 This may be the end of the if or the next else/elseif. */
163 /* Label at the top of the loop; place to loop back to. */
165 /* Label at the end of the whole construct. */
167 /* Label before a jump that branches to the end of the whole
168 construct. This is where destructors go if any. */
170 /* Label for `continue' statement to jump to;
171 this is in front of the stepper of the loop. */
174 /* For variable binding contours. */
177 /* Sequence number of this binding contour within the function,
178 in order of entry. */
179 int block_start_count;
180 /* Nonzero => value to restore stack to on exit. */
182 /* The NOTE that starts this contour.
183 Used by expand_goto to check whether the destination
184 is within each contour or not. */
186 /* Innermost containing binding contour that has a stack level. */
187 struct nesting *innermost_stack_block;
188 /* List of cleanups to be run on exit from this contour.
189 This is a list of expressions to be evaluated.
190 The TREE_PURPOSE of each link is the ..._DECL node
191 which the cleanup pertains to. */
193 /* List of cleanup-lists of blocks containing this block,
194 as they were at the locus where this block appears.
195 There is an element for each containing block,
196 ordered innermost containing block first.
197 The tail of this list can be 0,
198 if all remaining elements would be empty lists.
199 The element's TREE_VALUE is the cleanup-list of that block,
200 which may be null. */
202 /* Chain of labels defined inside this binding contour.
203 For contours that have stack levels or cleanups. */
204 struct label_chain *label_chain;
205 /* Number of function calls seen, as of start of this block. */
206 int n_function_calls;
207 /* Nonzero if this is associated with a EH region. */
208 int exception_region;
209 /* The saved target_temp_slot_level from our outer block.
210 We may reset target_temp_slot_level to be the level of
211 this block, if that is done, target_temp_slot_level
212 reverts to the saved target_temp_slot_level at the very
214 int block_target_temp_slot_level;
215 /* True if we are currently emitting insns in an area of
216 output code that is controlled by a conditional
217 expression. This is used by the cleanup handling code to
218 generate conditional cleanup actions. */
219 int conditional_code;
220 /* A place to move the start of the exception region for any
221 of the conditional cleanups, must be at the end or after
222 the start of the last unconditional cleanup, and before any
223 conditional branch points. */
224 rtx last_unconditional_cleanup;
225 /* When in a conditional context, this is the specific
226 cleanup list associated with last_unconditional_cleanup,
227 where we place the conditionalized cleanups. */
230 /* For switch (C) or case (Pascal) statements,
231 and also for dummies (see `expand_start_case_dummy'). */
234 /* The insn after which the case dispatch should finally
235 be emitted. Zero for a dummy. */
237 /* A list of case labels; it is first built as an AVL tree.
238 During expand_end_case, this is converted to a list, and may be
239 rearranged into a nearly balanced binary tree. */
240 struct case_node *case_list;
241 /* Label to jump to if no case matches. */
243 /* The expression to be dispatched on. */
245 /* Type that INDEX_EXPR should be converted to. */
247 /* Name of this kind of statement, for warnings. */
248 const char *printname;
249 /* Used to save no_line_numbers till we see the first case label.
250 We set this to -1 when we see the first case label in this
252 int line_number_status;
257 /* Allocate and return a new `struct nesting'. */
259 #define ALLOC_NESTING() \
260 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
262 /* Pop the nesting stack element by element until we pop off
263 the element which is at the top of STACK.
264 Update all the other stacks, popping off elements from them
265 as we pop them from nesting_stack. */
267 #define POPSTACK(STACK) \
268 do { struct nesting *target = STACK; \
269 struct nesting *this; \
270 do { this = nesting_stack; \
271 if (loop_stack == this) \
272 loop_stack = loop_stack->next; \
273 if (cond_stack == this) \
274 cond_stack = cond_stack->next; \
275 if (block_stack == this) \
276 block_stack = block_stack->next; \
277 if (stack_block_stack == this) \
278 stack_block_stack = stack_block_stack->next; \
279 if (case_stack == this) \
280 case_stack = case_stack->next; \
281 nesting_depth = nesting_stack->depth - 1; \
282 nesting_stack = this->all; \
283 obstack_free (&stmt_obstack, this); } \
284 while (this != target); } while (0)
286 /* In some cases it is impossible to generate code for a forward goto
287 until the label definition is seen. This happens when it may be necessary
288 for the goto to reset the stack pointer: we don't yet know how to do that.
289 So expand_goto puts an entry on this fixup list.
290 Each time a binding contour that resets the stack is exited,
292 If the target label has now been defined, we can insert the proper code. */
296 /* Points to following fixup. */
297 struct goto_fixup *next;
298 /* Points to the insn before the jump insn.
299 If more code must be inserted, it goes after this insn. */
301 /* The LABEL_DECL that this jump is jumping to, or 0
302 for break, continue or return. */
304 /* The BLOCK for the place where this goto was found. */
306 /* The CODE_LABEL rtx that this is jumping to. */
308 /* Number of binding contours started in current function
309 before the label reference. */
310 int block_start_count;
311 /* The outermost stack level that should be restored for this jump.
312 Each time a binding contour that resets the stack is exited,
313 if the target label is *not* yet defined, this slot is updated. */
315 /* List of lists of cleanup expressions to be run by this goto.
316 There is one element for each block that this goto is within.
317 The tail of this list can be 0,
318 if all remaining elements would be empty.
319 The TREE_VALUE contains the cleanup list of that block as of the
320 time this goto was seen.
321 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
322 tree cleanup_list_list;
325 /* Within any binding contour that must restore a stack level,
326 all labels are recorded with a chain of these structures. */
330 /* Points to following fixup. */
331 struct label_chain *next;
337 /* Chain of all pending binding contours. */
338 struct nesting *x_block_stack;
340 /* If any new stacks are added here, add them to POPSTACKS too. */
342 /* Chain of all pending binding contours that restore stack levels
344 struct nesting *x_stack_block_stack;
346 /* Chain of all pending conditional statements. */
347 struct nesting *x_cond_stack;
349 /* Chain of all pending loops. */
350 struct nesting *x_loop_stack;
352 /* Chain of all pending case or switch statements. */
353 struct nesting *x_case_stack;
355 /* Separate chain including all of the above,
356 chained through the `all' field. */
357 struct nesting *x_nesting_stack;
359 /* Number of entries on nesting_stack now. */
362 /* Number of binding contours started so far in this function. */
363 int x_block_start_count;
365 /* Each time we expand an expression-statement,
366 record the expr's type and its RTL value here. */
367 tree x_last_expr_type;
368 rtx x_last_expr_value;
370 /* Nonzero if within a ({...}) grouping, in which case we must
371 always compute a value for each expr-stmt in case it is the last one. */
372 int x_expr_stmts_for_value;
374 /* Filename and line number of last line-number note,
375 whether we actually emitted it or not. */
376 const char *x_emit_filename;
379 struct goto_fixup *x_goto_fixup_chain;
382 #define block_stack (cfun->stmt->x_block_stack)
383 #define stack_block_stack (cfun->stmt->x_stack_block_stack)
384 #define cond_stack (cfun->stmt->x_cond_stack)
385 #define loop_stack (cfun->stmt->x_loop_stack)
386 #define case_stack (cfun->stmt->x_case_stack)
387 #define nesting_stack (cfun->stmt->x_nesting_stack)
388 #define nesting_depth (cfun->stmt->x_nesting_depth)
389 #define current_block_start_count (cfun->stmt->x_block_start_count)
390 #define last_expr_type (cfun->stmt->x_last_expr_type)
391 #define last_expr_value (cfun->stmt->x_last_expr_value)
392 #define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
393 #define emit_filename (cfun->stmt->x_emit_filename)
394 #define emit_lineno (cfun->stmt->x_emit_lineno)
395 #define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)
397 /* Non-zero if we are using EH to handle cleanus. */
398 static int using_eh_for_cleanups_p = 0;
400 static int n_occurrences PARAMS ((int, const char *));
401 static void expand_goto_internal PARAMS ((tree, rtx, rtx));
402 static int expand_fixup PARAMS ((tree, rtx, rtx));
403 static rtx expand_nl_handler_label PARAMS ((rtx, rtx));
404 static void expand_nl_goto_receiver PARAMS ((void));
405 static void expand_nl_goto_receivers PARAMS ((struct nesting *));
406 static void fixup_gotos PARAMS ((struct nesting *, rtx, tree,
408 static void expand_null_return_1 PARAMS ((rtx, int));
409 static void expand_value_return PARAMS ((rtx));
410 static int tail_recursion_args PARAMS ((tree, tree));
411 static void expand_cleanups PARAMS ((tree, tree, int, int));
412 static void check_seenlabel PARAMS ((void));
413 static void do_jump_if_equal PARAMS ((rtx, rtx, rtx, int));
414 static int estimate_case_costs PARAMS ((case_node_ptr));
415 static void group_case_nodes PARAMS ((case_node_ptr));
416 static void balance_case_nodes PARAMS ((case_node_ptr *,
418 static int node_has_low_bound PARAMS ((case_node_ptr, tree));
419 static int node_has_high_bound PARAMS ((case_node_ptr, tree));
420 static int node_is_bounded PARAMS ((case_node_ptr, tree));
421 static void emit_jump_if_reachable PARAMS ((rtx));
422 static void emit_case_nodes PARAMS ((rtx, case_node_ptr, rtx, tree));
423 static struct case_node *case_tree2list PARAMS ((case_node *, case_node *));
424 static void mark_cond_nesting PARAMS ((struct nesting *));
425 static void mark_loop_nesting PARAMS ((struct nesting *));
426 static void mark_block_nesting PARAMS ((struct nesting *));
427 static void mark_case_nesting PARAMS ((struct nesting *));
428 static void mark_case_node PARAMS ((struct case_node *));
429 static void mark_goto_fixup PARAMS ((struct goto_fixup *));
430 static void free_case_nodes PARAMS ((case_node_ptr));
433 using_eh_for_cleanups ()
435 using_eh_for_cleanups_p = 1;
438 /* Mark N (known to be a cond-nesting) for GC. */
441 mark_cond_nesting (n)
446 ggc_mark_rtx (n->exit_label);
447 ggc_mark_rtx (n->data.cond.endif_label);
448 ggc_mark_rtx (n->data.cond.next_label);
454 /* Mark N (known to be a loop-nesting) for GC. */
457 mark_loop_nesting (n)
463 ggc_mark_rtx (n->exit_label);
464 ggc_mark_rtx (n->data.loop.start_label);
465 ggc_mark_rtx (n->data.loop.end_label);
466 ggc_mark_rtx (n->data.loop.alt_end_label);
467 ggc_mark_rtx (n->data.loop.continue_label);
473 /* Mark N (known to be a block-nesting) for GC. */
476 mark_block_nesting (n)
481 struct label_chain *l;
483 ggc_mark_rtx (n->exit_label);
484 ggc_mark_rtx (n->data.block.stack_level);
485 ggc_mark_rtx (n->data.block.first_insn);
486 ggc_mark_tree (n->data.block.cleanups);
487 ggc_mark_tree (n->data.block.outer_cleanups);
489 for (l = n->data.block.label_chain; l != NULL; l = l->next)
492 ggc_mark_tree (l->label);
495 ggc_mark_rtx (n->data.block.last_unconditional_cleanup);
497 /* ??? cleanup_ptr never points outside the stack, does it? */
503 /* Mark N (known to be a case-nesting) for GC. */
506 mark_case_nesting (n)
511 ggc_mark_rtx (n->exit_label);
512 ggc_mark_rtx (n->data.case_stmt.start);
514 ggc_mark_tree (n->data.case_stmt.default_label);
515 ggc_mark_tree (n->data.case_stmt.index_expr);
516 ggc_mark_tree (n->data.case_stmt.nominal_type);
518 mark_case_node (n->data.case_stmt.case_list);
531 ggc_mark_tree (c->low);
532 ggc_mark_tree (c->high);
533 ggc_mark_tree (c->code_label);
535 mark_case_node (c->right);
536 mark_case_node (c->left);
544 struct goto_fixup *g;
549 ggc_mark_rtx (g->before_jump);
550 ggc_mark_tree (g->target);
551 ggc_mark_tree (g->context);
552 ggc_mark_rtx (g->target_rtl);
553 ggc_mark_rtx (g->stack_level);
554 ggc_mark_tree (g->cleanup_list_list);
560 /* Clear out all parts of the state in F that can safely be discarded
561 after the function has been compiled, to let garbage collection
562 reclaim the memory. */
568 /* We're about to free the function obstack. If we hold pointers to
569 things allocated there, then we'll try to mark them when we do
570 GC. So, we clear them out here explicitly. */
580 struct stmt_status *p;
585 mark_block_nesting (p->x_block_stack);
586 mark_cond_nesting (p->x_cond_stack);
587 mark_loop_nesting (p->x_loop_stack);
588 mark_case_nesting (p->x_case_stack);
590 ggc_mark_tree (p->x_last_expr_type);
591 /* last_epxr_value is only valid if last_expr_type is nonzero. */
592 if (p->x_last_expr_type)
593 ggc_mark_rtx (p->x_last_expr_value);
595 mark_goto_fixup (p->x_goto_fixup_chain);
601 gcc_obstack_init (&stmt_obstack);
605 init_stmt_for_function ()
607 cfun->stmt = (struct stmt_status *) xmalloc (sizeof (struct stmt_status));
609 /* We are not currently within any block, conditional, loop or case. */
611 stack_block_stack = 0;
618 current_block_start_count = 0;
620 /* No gotos have been expanded yet. */
621 goto_fixup_chain = 0;
623 /* We are not processing a ({...}) grouping. */
624 expr_stmts_for_value = 0;
626 last_expr_value = NULL_RTX;
629 /* Return nonzero if anything is pushed on the loop, condition, or case
634 return cond_stack || loop_stack || case_stack;
637 /* Record the current file and line. Called from emit_line_note. */
639 set_file_and_line_for_stmt (file, line)
643 /* If we're outputting an inline function, and we add a line note,
644 there may be no CFUN->STMT information. So, there's no need to
648 emit_filename = file;
653 /* Emit a no-op instruction. */
660 last_insn = get_last_insn ();
662 && (GET_CODE (last_insn) == CODE_LABEL
663 || (GET_CODE (last_insn) == NOTE
664 && prev_real_insn (last_insn) == 0)))
665 emit_insn (gen_nop ());
668 /* Return the rtx-label that corresponds to a LABEL_DECL,
669 creating it if necessary. */
675 if (TREE_CODE (label) != LABEL_DECL)
678 if (DECL_RTL (label))
679 return DECL_RTL (label);
681 return DECL_RTL (label) = gen_label_rtx ();
684 /* Add an unconditional jump to LABEL as the next sequential instruction. */
690 do_pending_stack_adjust ();
691 emit_jump_insn (gen_jump (label));
695 /* Emit code to jump to the address
696 specified by the pointer expression EXP. */
699 expand_computed_goto (exp)
702 rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);
704 #ifdef POINTERS_EXTEND_UNSIGNED
705 x = convert_memory_address (Pmode, x);
709 /* Be sure the function is executable. */
710 if (current_function_check_memory_usage)
711 emit_library_call (chkr_check_exec_libfunc, LCT_CONST_MAKE_BLOCK,
712 VOIDmode, 1, x, ptr_mode);
714 do_pending_stack_adjust ();
715 emit_indirect_jump (x);
717 current_function_has_computed_jump = 1;
720 /* Handle goto statements and the labels that they can go to. */
722 /* Specify the location in the RTL code of a label LABEL,
723 which is a LABEL_DECL tree node.
725 This is used for the kind of label that the user can jump to with a
726 goto statement, and for alternatives of a switch or case statement.
727 RTL labels generated for loops and conditionals don't go through here;
728 they are generated directly at the RTL level, by other functions below.
730 Note that this has nothing to do with defining label *names*.
731 Languages vary in how they do that and what that even means. */
737 struct label_chain *p;
739 do_pending_stack_adjust ();
740 emit_label (label_rtx (label));
741 if (DECL_NAME (label))
742 LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));
744 if (stack_block_stack != 0)
746 p = (struct label_chain *) ggc_alloc (sizeof (struct label_chain));
747 p->next = stack_block_stack->data.block.label_chain;
748 stack_block_stack->data.block.label_chain = p;
753 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
754 from nested functions. */
757 declare_nonlocal_label (label)
760 rtx slot = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
762 nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels);
763 LABEL_PRESERVE_P (label_rtx (label)) = 1;
764 if (nonlocal_goto_handler_slots == 0)
766 emit_stack_save (SAVE_NONLOCAL,
767 &nonlocal_goto_stack_level,
768 PREV_INSN (tail_recursion_reentry));
770 nonlocal_goto_handler_slots
771 = gen_rtx_EXPR_LIST (VOIDmode, slot, nonlocal_goto_handler_slots);
774 /* Generate RTL code for a `goto' statement with target label LABEL.
775 LABEL should be a LABEL_DECL tree node that was or will later be
776 defined with `expand_label'. */
784 /* Check for a nonlocal goto to a containing function. */
785 context = decl_function_context (label);
786 if (context != 0 && context != current_function_decl)
788 struct function *p = find_function_data (context);
789 rtx label_ref = gen_rtx_LABEL_REF (Pmode, label_rtx (label));
790 rtx handler_slot, static_chain, save_area, insn;
793 /* Find the corresponding handler slot for this label. */
794 handler_slot = p->x_nonlocal_goto_handler_slots;
795 for (link = p->x_nonlocal_labels; TREE_VALUE (link) != label;
796 link = TREE_CHAIN (link))
797 handler_slot = XEXP (handler_slot, 1);
798 handler_slot = XEXP (handler_slot, 0);
800 p->has_nonlocal_label = 1;
801 current_function_has_nonlocal_goto = 1;
802 LABEL_REF_NONLOCAL_P (label_ref) = 1;
804 /* Copy the rtl for the slots so that they won't be shared in
805 case the virtual stack vars register gets instantiated differently
806 in the parent than in the child. */
808 static_chain = copy_to_reg (lookup_static_chain (label));
810 /* Get addr of containing function's current nonlocal goto handler,
811 which will do any cleanups and then jump to the label. */
812 handler_slot = copy_to_reg (replace_rtx (copy_rtx (handler_slot),
813 virtual_stack_vars_rtx,
816 /* Get addr of containing function's nonlocal save area. */
817 save_area = p->x_nonlocal_goto_stack_level;
819 save_area = replace_rtx (copy_rtx (save_area),
820 virtual_stack_vars_rtx, static_chain);
822 #if HAVE_nonlocal_goto
823 if (HAVE_nonlocal_goto)
824 emit_insn (gen_nonlocal_goto (static_chain, handler_slot,
825 save_area, label_ref));
829 /* Restore frame pointer for containing function.
830 This sets the actual hard register used for the frame pointer
831 to the location of the function's incoming static chain info.
832 The non-local goto handler will then adjust it to contain the
833 proper value and reload the argument pointer, if needed. */
834 emit_move_insn (hard_frame_pointer_rtx, static_chain);
835 emit_stack_restore (SAVE_NONLOCAL, save_area, NULL_RTX);
837 /* USE of hard_frame_pointer_rtx added for consistency;
838 not clear if really needed. */
839 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
840 emit_insn (gen_rtx_USE (VOIDmode, stack_pointer_rtx));
841 emit_indirect_jump (handler_slot);
844 /* Search backwards to the jump insn and mark it as a
846 for (insn = get_last_insn ();
847 GET_CODE (insn) != JUMP_INSN;
848 insn = PREV_INSN (insn))
850 REG_NOTES (insn) = alloc_EXPR_LIST (REG_NON_LOCAL_GOTO, const0_rtx,
854 expand_goto_internal (label, label_rtx (label), NULL_RTX);
857 /* Generate RTL code for a `goto' statement with target label BODY.
858 LABEL should be a LABEL_REF.
859 LAST_INSN, if non-0, is the rtx we should consider as the last
860 insn emitted (for the purposes of cleaning up a return). */
863 expand_goto_internal (body, label, last_insn)
868 struct nesting *block;
871 if (GET_CODE (label) != CODE_LABEL)
874 /* If label has already been defined, we can tell now
875 whether and how we must alter the stack level. */
877 if (PREV_INSN (label) != 0)
879 /* Find the innermost pending block that contains the label.
880 (Check containment by comparing insn-uids.)
881 Then restore the outermost stack level within that block,
882 and do cleanups of all blocks contained in it. */
883 for (block = block_stack; block; block = block->next)
885 if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
887 if (block->data.block.stack_level != 0)
888 stack_level = block->data.block.stack_level;
889 /* Execute the cleanups for blocks we are exiting. */
890 if (block->data.block.cleanups != 0)
892 expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1);
893 do_pending_stack_adjust ();
899 /* Ensure stack adjust isn't done by emit_jump, as this
900 would clobber the stack pointer. This one should be
901 deleted as dead by flow. */
902 clear_pending_stack_adjust ();
903 do_pending_stack_adjust ();
905 /* Don't do this adjust if it's to the end label and this function
906 is to return with a depressed stack pointer. */
907 if (label == return_label
908 && (((TREE_CODE (TREE_TYPE (current_function_decl))
910 && (TYPE_RETURNS_STACK_DEPRESSED
911 (TREE_TYPE (current_function_decl))))))
914 emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
917 if (body != 0 && DECL_TOO_LATE (body))
918 error ("jump to `%s' invalidly jumps into binding contour",
919 IDENTIFIER_POINTER (DECL_NAME (body)));
921 /* Label not yet defined: may need to put this goto
922 on the fixup list. */
923 else if (! expand_fixup (body, label, last_insn))
925 /* No fixup needed. Record that the label is the target
926 of at least one goto that has no fixup. */
928 TREE_ADDRESSABLE (body) = 1;
934 /* Generate if necessary a fixup for a goto
935 whose target label in tree structure (if any) is TREE_LABEL
936 and whose target in rtl is RTL_LABEL.
938 If LAST_INSN is nonzero, we pretend that the jump appears
939 after insn LAST_INSN instead of at the current point in the insn stream.
941 The fixup will be used later to insert insns just before the goto.
942 Those insns will restore the stack level as appropriate for the
943 target label, and will (in the case of C++) also invoke any object
944 destructors which have to be invoked when we exit the scopes which
945 are exited by the goto.
947 Value is nonzero if a fixup is made. */
950 expand_fixup (tree_label, rtl_label, last_insn)
955 struct nesting *block, *end_block;
957 /* See if we can recognize which block the label will be output in.
958 This is possible in some very common cases.
959 If we succeed, set END_BLOCK to that block.
960 Otherwise, set it to 0. */
963 && (rtl_label == cond_stack->data.cond.endif_label
964 || rtl_label == cond_stack->data.cond.next_label))
965 end_block = cond_stack;
966 /* If we are in a loop, recognize certain labels which
967 are likely targets. This reduces the number of fixups
968 we need to create. */
970 && (rtl_label == loop_stack->data.loop.start_label
971 || rtl_label == loop_stack->data.loop.end_label
972 || rtl_label == loop_stack->data.loop.continue_label))
973 end_block = loop_stack;
977 /* Now set END_BLOCK to the binding level to which we will return. */
981 struct nesting *next_block = end_block->all;
984 /* First see if the END_BLOCK is inside the innermost binding level.
985 If so, then no cleanups or stack levels are relevant. */
986 while (next_block && next_block != block)
987 next_block = next_block->all;
992 /* Otherwise, set END_BLOCK to the innermost binding level
993 which is outside the relevant control-structure nesting. */
994 next_block = block_stack->next;
995 for (block = block_stack; block != end_block; block = block->all)
996 if (block == next_block)
997 next_block = next_block->next;
998 end_block = next_block;
1001 /* Does any containing block have a stack level or cleanups?
1002 If not, no fixup is needed, and that is the normal case
1003 (the only case, for standard C). */
1004 for (block = block_stack; block != end_block; block = block->next)
1005 if (block->data.block.stack_level != 0
1006 || block->data.block.cleanups != 0)
1009 if (block != end_block)
1011 /* Ok, a fixup is needed. Add a fixup to the list of such. */
1012 struct goto_fixup *fixup
1013 = (struct goto_fixup *) ggc_alloc (sizeof (struct goto_fixup));
1014 /* In case an old stack level is restored, make sure that comes
1015 after any pending stack adjust. */
1016 /* ?? If the fixup isn't to come at the present position,
1017 doing the stack adjust here isn't useful. Doing it with our
1018 settings at that location isn't useful either. Let's hope
1021 do_pending_stack_adjust ();
1022 fixup->target = tree_label;
1023 fixup->target_rtl = rtl_label;
1025 /* Create a BLOCK node and a corresponding matched set of
1026 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
1027 this point. The notes will encapsulate any and all fixup
1028 code which we might later insert at this point in the insn
1029 stream. Also, the BLOCK node will be the parent (i.e. the
1030 `SUPERBLOCK') of any other BLOCK nodes which we might create
1031 later on when we are expanding the fixup code.
1033 Note that optimization passes (including expand_end_loop)
1034 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
1035 as a placeholder. */
1038 register rtx original_before_jump
1039 = last_insn ? last_insn : get_last_insn ();
1044 block = make_node (BLOCK);
1045 TREE_USED (block) = 1;
1047 if (!cfun->x_whole_function_mode_p)
1048 insert_block (block);
1052 = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
1053 BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
1058 start = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
1059 if (cfun->x_whole_function_mode_p)
1060 NOTE_BLOCK (start) = block;
1061 fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_DELETED);
1062 end = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
1063 if (cfun->x_whole_function_mode_p)
1064 NOTE_BLOCK (end) = block;
1065 fixup->context = block;
1067 emit_insns_after (start, original_before_jump);
1070 fixup->block_start_count = current_block_start_count;
1071 fixup->stack_level = 0;
1072 fixup->cleanup_list_list
1073 = ((block->data.block.outer_cleanups
1074 || block->data.block.cleanups)
1075 ? tree_cons (NULL_TREE, block->data.block.cleanups,
1076 block->data.block.outer_cleanups)
1078 fixup->next = goto_fixup_chain;
1079 goto_fixup_chain = fixup;
1085 /* Expand any needed fixups in the outputmost binding level of the
1086 function. FIRST_INSN is the first insn in the function. */
1089 expand_fixups (first_insn)
1092 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0);
1095 /* When exiting a binding contour, process all pending gotos requiring fixups.
1096 THISBLOCK is the structure that describes the block being exited.
1097 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
1098 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
1099 FIRST_INSN is the insn that began this contour.
1101 Gotos that jump out of this contour must restore the
1102 stack level and do the cleanups before actually jumping.
1104 DONT_JUMP_IN nonzero means report error there is a jump into this
1105 contour from before the beginning of the contour.
1106 This is also done if STACK_LEVEL is nonzero. */
1109 fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in)
1110 struct nesting *thisblock;
1116 register struct goto_fixup *f, *prev;
1118 /* F is the fixup we are considering; PREV is the previous one. */
1119 /* We run this loop in two passes so that cleanups of exited blocks
1120 are run first, and blocks that are exited are marked so
1123 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1125 /* Test for a fixup that is inactive because it is already handled. */
1126 if (f->before_jump == 0)
1128 /* Delete inactive fixup from the chain, if that is easy to do. */
1130 prev->next = f->next;
1132 /* Has this fixup's target label been defined?
1133 If so, we can finalize it. */
1134 else if (PREV_INSN (f->target_rtl) != 0)
1136 register rtx cleanup_insns;
1138 /* If this fixup jumped into this contour from before the beginning
1139 of this contour, report an error. This code used to use
1140 the first non-label insn after f->target_rtl, but that's
1141 wrong since such can be added, by things like put_var_into_stack
1142 and have INSN_UIDs that are out of the range of the block. */
1143 /* ??? Bug: this does not detect jumping in through intermediate
1144 blocks that have stack levels or cleanups.
1145 It detects only a problem with the innermost block
1146 around the label. */
1148 && (dont_jump_in || stack_level || cleanup_list)
1149 && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
1150 && INSN_UID (first_insn) > INSN_UID (f->before_jump)
1151 && ! DECL_ERROR_ISSUED (f->target))
1153 error_with_decl (f->target,
1154 "label `%s' used before containing binding contour");
1155 /* Prevent multiple errors for one label. */
1156 DECL_ERROR_ISSUED (f->target) = 1;
1159 /* We will expand the cleanups into a sequence of their own and
1160 then later on we will attach this new sequence to the insn
1161 stream just ahead of the actual jump insn. */
1165 /* Temporarily restore the lexical context where we will
1166 logically be inserting the fixup code. We do this for the
1167 sake of getting the debugging information right. */
1170 set_block (f->context);
1172 /* Expand the cleanups for blocks this jump exits. */
1173 if (f->cleanup_list_list)
1176 for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
1177 /* Marked elements correspond to blocks that have been closed.
1178 Do their cleanups. */
1179 if (TREE_ADDRESSABLE (lists)
1180 && TREE_VALUE (lists) != 0)
1182 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1183 /* Pop any pushes done in the cleanups,
1184 in case function is about to return. */
1185 do_pending_stack_adjust ();
1189 /* Restore stack level for the biggest contour that this
1190 jump jumps out of. */
1192 && ! (f->target_rtl == return_label
1193 && ((TREE_CODE (TREE_TYPE (current_function_decl))
1195 && (TYPE_RETURNS_STACK_DEPRESSED
1196 (TREE_TYPE (current_function_decl))))))
1197 emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);
1199 /* Finish up the sequence containing the insns which implement the
1200 necessary cleanups, and then attach that whole sequence to the
1201 insn stream just ahead of the actual jump insn. Attaching it
1202 at that point insures that any cleanups which are in fact
1203 implicit C++ object destructions (which must be executed upon
1204 leaving the block) appear (to the debugger) to be taking place
1205 in an area of the generated code where the object(s) being
1206 destructed are still "in scope". */
1208 cleanup_insns = get_insns ();
1212 emit_insns_after (cleanup_insns, f->before_jump);
1218 /* For any still-undefined labels, do the cleanups for this block now.
1219 We must do this now since items in the cleanup list may go out
1220 of scope when the block ends. */
1221 for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
1222 if (f->before_jump != 0
1223 && PREV_INSN (f->target_rtl) == 0
1224 /* Label has still not appeared. If we are exiting a block with
1225 a stack level to restore, that started before the fixup,
1226 mark this stack level as needing restoration
1227 when the fixup is later finalized. */
1229 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1230 means the label is undefined. That's erroneous, but possible. */
1231 && (thisblock->data.block.block_start_count
1232 <= f->block_start_count))
1234 tree lists = f->cleanup_list_list;
1237 for (; lists; lists = TREE_CHAIN (lists))
1238 /* If the following elt. corresponds to our containing block
1239 then the elt. must be for this block. */
1240 if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
1244 set_block (f->context);
1245 expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1);
1246 do_pending_stack_adjust ();
1247 cleanup_insns = get_insns ();
1250 if (cleanup_insns != 0)
1252 = emit_insns_after (cleanup_insns, f->before_jump);
1254 f->cleanup_list_list = TREE_CHAIN (lists);
1258 f->stack_level = stack_level;
1262 /* Return the number of times character C occurs in string S. */
1264 n_occurrences (c, s)
1274 /* Generate RTL for an asm statement (explicit assembler code).
1275 BODY is a STRING_CST node containing the assembler code text,
1276 or an ADDR_EXPR containing a STRING_CST. */
1282 if (current_function_check_memory_usage)
1284 error ("`asm' cannot be used in function where memory usage is checked");
1288 if (TREE_CODE (body) == ADDR_EXPR)
1289 body = TREE_OPERAND (body, 0);
1291 emit_insn (gen_rtx_ASM_INPUT (VOIDmode,
1292 TREE_STRING_POINTER (body)));
1296 /* Generate RTL for an asm statement with arguments.
1297 STRING is the instruction template.
1298 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1299 Each output or input has an expression in the TREE_VALUE and
1300 a constraint-string in the TREE_PURPOSE.
1301 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1302 that is clobbered by this insn.
1304 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1305 Some elements of OUTPUTS may be replaced with trees representing temporary
1306 values. The caller should copy those temporary values to the originally
1309 VOL nonzero means the insn is volatile; don't optimize it. */
1312 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
1313 tree string, outputs, inputs, clobbers;
1315 const char *filename;
1318 rtvec argvec, constraints;
1320 int ninputs = list_length (inputs);
1321 int noutputs = list_length (outputs);
1326 /* Vector of RTX's of evaluated output operands. */
1327 rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1328 int *inout_opnum = (int *) alloca (noutputs * sizeof (int));
1329 rtx *real_output_rtx = (rtx *) alloca (noutputs * sizeof (rtx));
1330 enum machine_mode *inout_mode
1331 = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode));
1332 /* The insn we have emitted. */
1334 int old_generating_concat_p = generating_concat_p;
1336 /* An ASM with no outputs needs to be treated as volatile, for now. */
1340 if (current_function_check_memory_usage)
1342 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1346 #ifdef MD_ASM_CLOBBERS
1347 /* Sometimes we wish to automatically clobber registers across an asm.
1348 Case in point is when the i386 backend moved from cc0 to a hard reg --
1349 maintaining source-level compatability means automatically clobbering
1350 the flags register. */
1351 MD_ASM_CLOBBERS (clobbers);
1354 if (current_function_check_memory_usage)
1356 error ("`asm' cannot be used in function where memory usage is checked");
1360 /* Count the number of meaningful clobbered registers, ignoring what
1361 we would ignore later. */
1363 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1365 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1367 i = decode_reg_name (regname);
1368 if (i >= 0 || i == -4)
1371 error ("unknown register name `%s' in `asm'", regname);
1376 /* Check that the number of alternatives is constant across all
1378 if (outputs || inputs)
1380 tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
1381 int nalternatives = n_occurrences (',', TREE_STRING_POINTER (tmp));
1384 if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
1386 error ("too many alternatives in `asm'");
1393 const char *constraint = TREE_STRING_POINTER (TREE_PURPOSE (tmp));
1395 if (n_occurrences (',', constraint) != nalternatives)
1397 error ("operand constraints for `asm' differ in number of alternatives");
1401 if (TREE_CHAIN (tmp))
1402 tmp = TREE_CHAIN (tmp);
1404 tmp = next, next = 0;
1408 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1410 tree val = TREE_VALUE (tail);
1411 tree type = TREE_TYPE (val);
1412 const char *constraint;
1420 /* If there's an erroneous arg, emit no insn. */
1421 if (TREE_TYPE (val) == error_mark_node)
1424 /* Make sure constraint has `=' and does not have `+'. Also, see
1425 if it allows any register. Be liberal on the latter test, since
1426 the worst that happens if we get it wrong is we issue an error
1429 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1430 c_len = strlen (constraint);
1432 /* Allow the `=' or `+' to not be at the beginning of the string,
1433 since it wasn't explicitly documented that way, and there is a
1434 large body of code that puts it last. Swap the character to
1435 the front, so as not to uglify any place else. */
1439 if ((p = strchr (constraint, '=')) != NULL)
1441 if ((p = strchr (constraint, '+')) != NULL)
1444 error ("output operand constraint lacks `='");
1448 is_inout = *p == '+';
1452 /* Have to throw away this constraint string and get a new one. */
1453 char *buf = alloca (c_len + 1);
1456 memcpy (buf + 1, constraint, j);
1457 memcpy (buf + 1 + j, p + 1, c_len - j); /* not -j-1 - copy null */
1458 constraint = ggc_alloc_string (buf, c_len);
1462 "output constraint `%c' for operand %d is not at the beginning",
1466 /* Make sure we can specify the matching operand. */
1467 if (is_inout && i > 9)
1469 error ("output operand constraint %d contains `+'", i);
1473 for (j = 1; j < c_len; j++)
1474 switch (constraint[j])
1478 error ("operand constraint contains '+' or '=' at illegal position.");
1482 if (i + 1 == ninputs + noutputs)
1484 error ("`%%' constraint used with last operand");
1489 case '?': case '!': case '*': case '&': case '#':
1490 case 'E': case 'F': case 'G': case 'H':
1491 case 's': case 'i': case 'n':
1492 case 'I': case 'J': case 'K': case 'L': case 'M':
1493 case 'N': case 'O': case 'P': case ',':
1496 case '0': case '1': case '2': case '3': case '4':
1497 case '5': case '6': case '7': case '8': case '9':
1498 error ("matching constraint not valid in output operand");
1501 case 'V': case 'm': case 'o':
1506 /* ??? Before flow, auto inc/dec insns are not supposed to exist,
1507 excepting those that expand_call created. So match memory
1522 if (! ISALPHA (constraint[j]))
1524 error ("invalid punctuation `%c' in constraint",
1528 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1530 #ifdef EXTRA_CONSTRAINT
1533 /* Otherwise we can't assume anything about the nature of
1534 the constraint except that it isn't purely registers.
1535 Treat it like "g" and hope for the best. */
1543 /* If an output operand is not a decl or indirect ref and our constraint
1544 allows a register, make a temporary to act as an intermediate.
1545 Make the asm insn write into that, then our caller will copy it to
1546 the real output operand. Likewise for promoted variables. */
1548 generating_concat_p = 0;
1550 real_output_rtx[i] = NULL_RTX;
1551 if ((TREE_CODE (val) == INDIRECT_REF
1554 && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
1555 && ! (GET_CODE (DECL_RTL (val)) == REG
1556 && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
1561 mark_addressable (TREE_VALUE (tail));
1564 = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode,
1565 EXPAND_MEMORY_USE_WO);
1567 if (! allows_reg && GET_CODE (output_rtx[i]) != MEM)
1568 error ("output number %d not directly addressable", i);
1569 if ((! allows_mem && GET_CODE (output_rtx[i]) == MEM)
1570 || GET_CODE (output_rtx[i]) == CONCAT)
1572 real_output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1573 output_rtx[i] = gen_reg_rtx (GET_MODE (output_rtx[i]));
1575 emit_move_insn (output_rtx[i], real_output_rtx[i]);
1580 output_rtx[i] = assign_temp (type, 0, 0, 1);
1581 TREE_VALUE (tail) = make_tree (type, output_rtx[i]);
1584 generating_concat_p = old_generating_concat_p;
1588 inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail)));
1589 inout_opnum[ninout++] = i;
1594 if (ninputs + noutputs > MAX_RECOG_OPERANDS)
1596 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
1600 /* Make vectors for the expression-rtx and constraint strings. */
1602 argvec = rtvec_alloc (ninputs);
1603 constraints = rtvec_alloc (ninputs);
1605 body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
1606 : GET_MODE (output_rtx[0])),
1607 TREE_STRING_POINTER (string),
1608 empty_string, 0, argvec, constraints,
1611 MEM_VOLATILE_P (body) = vol;
1613 /* Eval the inputs and put them into ARGVEC.
1614 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1617 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
1620 int allows_reg = 0, allows_mem = 0;
1621 const char *constraint, *orig_constraint;
1625 /* If there's an erroneous arg, emit no insn,
1626 because the ASM_INPUT would get VOIDmode
1627 and that could cause a crash in reload. */
1628 if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
1631 /* ??? Can this happen, and does the error message make any sense? */
1632 if (TREE_PURPOSE (tail) == NULL_TREE)
1634 error ("hard register `%s' listed as input operand to `asm'",
1635 TREE_STRING_POINTER (TREE_VALUE (tail)) );
1639 constraint = TREE_STRING_POINTER (TREE_PURPOSE (tail));
1640 c_len = strlen (constraint);
1641 orig_constraint = constraint;
1643 /* Make sure constraint has neither `=', `+', nor '&'. */
1645 for (j = 0; j < c_len; j++)
1646 switch (constraint[j])
1648 case '+': case '=': case '&':
1649 if (constraint == orig_constraint)
1651 error ("input operand constraint contains `%c'",
1658 if (constraint == orig_constraint
1659 && i + 1 == ninputs - ninout)
1661 error ("`%%' constraint used with last operand");
1666 case 'V': case 'm': case 'o':
1671 case '?': case '!': case '*': case '#':
1672 case 'E': case 'F': case 'G': case 'H':
1673 case 's': case 'i': case 'n':
1674 case 'I': case 'J': case 'K': case 'L': case 'M':
1675 case 'N': case 'O': case 'P': case ',':
1678 /* Whether or not a numeric constraint allows a register is
1679 decided by the matching constraint, and so there is no need
1680 to do anything special with them. We must handle them in
1681 the default case, so that we don't unnecessarily force
1682 operands to memory. */
1683 case '0': case '1': case '2': case '3': case '4':
1684 case '5': case '6': case '7': case '8': case '9':
1685 if (constraint[j] >= '0' + noutputs)
1688 ("matching constraint references invalid operand number");
1692 /* Try and find the real constraint for this dup. */
1693 if ((j == 0 && c_len == 1)
1694 || (j == 1 && c_len == 2 && constraint[0] == '%'))
1698 for (j = constraint[j] - '0'; j > 0; --j)
1701 constraint = TREE_STRING_POINTER (TREE_PURPOSE (o));
1702 c_len = strlen (constraint);
1719 if (! ISALPHA (constraint[j]))
1721 error ("invalid punctuation `%c' in constraint",
1725 if (REG_CLASS_FROM_LETTER (constraint[j]) != NO_REGS)
1727 #ifdef EXTRA_CONSTRAINT
1730 /* Otherwise we can't assume anything about the nature of
1731 the constraint except that it isn't purely registers.
1732 Treat it like "g" and hope for the best. */
1740 if (! allows_reg && allows_mem)
1741 mark_addressable (TREE_VALUE (tail));
1743 op = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0);
1745 /* Never pass a CONCAT to an ASM. */
1746 generating_concat_p = 0;
1747 if (GET_CODE (op) == CONCAT)
1748 op = force_reg (GET_MODE (op), op);
1750 if (asm_operand_ok (op, constraint) <= 0)
1753 op = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), op);
1754 else if (!allows_mem)
1755 warning ("asm operand %d probably doesn't match constraints", i);
1756 else if (CONSTANT_P (op))
1757 op = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1759 else if (GET_CODE (op) == REG
1760 || GET_CODE (op) == SUBREG
1761 || GET_CODE (op) == CONCAT)
1763 tree type = TREE_TYPE (TREE_VALUE (tail));
1764 tree qual_type = build_qualified_type (type,
1766 | TYPE_QUAL_CONST));
1767 rtx memloc = assign_temp (qual_type, 1, 1, 1);
1769 emit_move_insn (memloc, op);
1773 else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
1774 /* We won't recognize volatile memory as available a
1775 memory_operand at this point. Ignore it. */
1777 else if (queued_subexp_p (op))
1780 /* ??? Leave this only until we have experience with what
1781 happens in combine and elsewhere when constraints are
1783 warning ("asm operand %d probably doesn't match constraints", i);
1785 generating_concat_p = old_generating_concat_p;
1786 ASM_OPERANDS_INPUT (body, i) = op;
1788 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
1789 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))),
1794 /* Protect all the operands from the queue now that they have all been
1797 generating_concat_p = 0;
1799 for (i = 0; i < ninputs - ninout; i++)
1800 ASM_OPERANDS_INPUT (body, i)
1801 = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);
1803 for (i = 0; i < noutputs; i++)
1804 output_rtx[i] = protect_from_queue (output_rtx[i], 1);
1806 /* For in-out operands, copy output rtx to input rtx. */
1807 for (i = 0; i < ninout; i++)
1809 int j = inout_opnum[i];
1811 ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
1813 ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
1814 = gen_rtx_ASM_INPUT (inout_mode[i], digit_string (j));
1817 generating_concat_p = old_generating_concat_p;
1819 /* Now, for each output, construct an rtx
1820 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1821 ARGVEC CONSTRAINTS))
1822 If there is more than one, put them inside a PARALLEL. */
1824 if (noutputs == 1 && nclobbers == 0)
1826 ASM_OPERANDS_OUTPUT_CONSTRAINT (body)
1827 = TREE_STRING_POINTER (TREE_PURPOSE (outputs));
1828 insn = emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
1831 else if (noutputs == 0 && nclobbers == 0)
1833 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1834 insn = emit_insn (body);
1845 body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
1847 /* For each output operand, store a SET. */
1848 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
1850 XVECEXP (body, 0, i)
1851 = gen_rtx_SET (VOIDmode,
1853 gen_rtx_ASM_OPERANDS
1854 (GET_MODE (output_rtx[i]),
1855 TREE_STRING_POINTER (string),
1856 TREE_STRING_POINTER (TREE_PURPOSE (tail)),
1857 i, argvec, constraints,
1860 MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
1863 /* If there are no outputs (but there are some clobbers)
1864 store the bare ASM_OPERANDS into the PARALLEL. */
1867 XVECEXP (body, 0, i++) = obody;
1869 /* Store (clobber REG) for each clobbered register specified. */
1871 for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
1873 const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
1874 int j = decode_reg_name (regname);
1878 if (j == -3) /* `cc', which is not a register */
1881 if (j == -4) /* `memory', don't cache memory across asm */
1883 XVECEXP (body, 0, i++)
1884 = gen_rtx_CLOBBER (VOIDmode,
1887 gen_rtx_SCRATCH (VOIDmode)));
1891 /* Ignore unknown register, error already signaled. */
1895 /* Use QImode since that's guaranteed to clobber just one reg. */
1896 XVECEXP (body, 0, i++)
1897 = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (QImode, j));
1900 insn = emit_insn (body);
1903 /* For any outputs that needed reloading into registers, spill them
1904 back to where they belong. */
1905 for (i = 0; i < noutputs; ++i)
1906 if (real_output_rtx[i])
1907 emit_move_insn (real_output_rtx[i], output_rtx[i]);
1912 /* Generate RTL to evaluate the expression EXP
1913 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1916 expand_expr_stmt (exp)
1919 /* If -W, warn about statements with no side effects,
1920 except for an explicit cast to void (e.g. for assert()), and
1921 except inside a ({...}) where they may be useful. */
1922 if (expr_stmts_for_value == 0 && exp != error_mark_node)
1924 if (! TREE_SIDE_EFFECTS (exp))
1926 if ((extra_warnings || warn_unused_value)
1927 && !(TREE_CODE (exp) == CONVERT_EXPR
1928 && VOID_TYPE_P (TREE_TYPE (exp))))
1929 warning_with_file_and_line (emit_filename, emit_lineno,
1930 "statement with no effect");
1932 else if (warn_unused_value)
1933 warn_if_unused_value (exp);
1936 /* If EXP is of function type and we are expanding statements for
1937 value, convert it to pointer-to-function. */
1938 if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
1939 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1941 /* The call to `expand_expr' could cause last_expr_type and
1942 last_expr_value to get reset. Therefore, we set last_expr_value
1943 and last_expr_type *after* calling expand_expr. */
1944 last_expr_value = expand_expr (exp,
1945 (expr_stmts_for_value
1946 ? NULL_RTX : const0_rtx),
1948 last_expr_type = TREE_TYPE (exp);
1950 /* If all we do is reference a volatile value in memory,
1951 copy it to a register to be sure it is actually touched. */
1952 if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM
1953 && TREE_THIS_VOLATILE (exp))
1955 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)
1957 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1958 copy_to_reg (last_expr_value);
1961 rtx lab = gen_label_rtx ();
1963 /* Compare the value with itself to reference it. */
1964 emit_cmp_and_jump_insns (last_expr_value, last_expr_value, EQ,
1965 expand_expr (TYPE_SIZE (last_expr_type),
1966 NULL_RTX, VOIDmode, 0),
1968 TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT,
1974 /* If this expression is part of a ({...}) and is in memory, we may have
1975 to preserve temporaries. */
1976 preserve_temp_slots (last_expr_value);
1978 /* Free any temporaries used to evaluate this expression. Any temporary
1979 used as a result of this expression will already have been preserved
1986 /* Warn if EXP contains any computations whose results are not used.
1987 Return 1 if a warning is printed; 0 otherwise. */
1990 warn_if_unused_value (exp)
1993 if (TREE_USED (exp))
1996 /* Don't warn about void constructs. This includes casting to void,
1997 void function calls, and statement expressions with a final cast
1999 if (VOID_TYPE_P (TREE_TYPE (exp)))
2002 /* If this is an expression with side effects, don't warn. */
2003 if (TREE_SIDE_EFFECTS (exp))
2006 switch (TREE_CODE (exp))
2008 case PREINCREMENT_EXPR:
2009 case POSTINCREMENT_EXPR:
2010 case PREDECREMENT_EXPR:
2011 case POSTDECREMENT_EXPR:
2016 case METHOD_CALL_EXPR:
2018 case TRY_CATCH_EXPR:
2019 case WITH_CLEANUP_EXPR:
2024 /* For a binding, warn if no side effect within it. */
2025 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2028 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2030 case TRUTH_ORIF_EXPR:
2031 case TRUTH_ANDIF_EXPR:
2032 /* In && or ||, warn if 2nd operand has no side effect. */
2033 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2036 if (TREE_NO_UNUSED_WARNING (exp))
2038 if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
2040 /* Let people do `(foo (), 0)' without a warning. */
2041 if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
2043 return warn_if_unused_value (TREE_OPERAND (exp, 1));
2047 case NON_LVALUE_EXPR:
2048 /* Don't warn about conversions not explicit in the user's program. */
2049 if (TREE_NO_UNUSED_WARNING (exp))
2051 /* Assignment to a cast usually results in a cast of a modify.
2052 Don't complain about that. There can be an arbitrary number of
2053 casts before the modify, so we must loop until we find the first
2054 non-cast expression and then test to see if that is a modify. */
2056 tree tem = TREE_OPERAND (exp, 0);
2058 while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
2059 tem = TREE_OPERAND (tem, 0);
2061 if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
2062 || TREE_CODE (tem) == CALL_EXPR)
2068 /* Don't warn about automatic dereferencing of references, since
2069 the user cannot control it. */
2070 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
2071 return warn_if_unused_value (TREE_OPERAND (exp, 0));
2075 /* Referencing a volatile value is a side effect, so don't warn. */
2077 || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
2078 && TREE_THIS_VOLATILE (exp))
2081 /* If this is an expression which has no operands, there is no value
2082 to be unused. There are no such language-independent codes,
2083 but front ends may define such. */
2084 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
2085 && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
2089 warning_with_file_and_line (emit_filename, emit_lineno,
2090 "value computed is not used");
2095 /* Clear out the memory of the last expression evaluated. */
2103 /* Begin a statement which will return a value.
2104 Return the RTL_EXPR for this statement expr.
2105 The caller must save that value and pass it to expand_end_stmt_expr. */
2108 expand_start_stmt_expr ()
2112 /* Make the RTL_EXPR node temporary, not momentary,
2113 so that rtl_expr_chain doesn't become garbage. */
2114 t = make_node (RTL_EXPR);
2115 do_pending_stack_adjust ();
2116 start_sequence_for_rtl_expr (t);
2118 expr_stmts_for_value++;
2122 /* Restore the previous state at the end of a statement that returns a value.
2123 Returns a tree node representing the statement's value and the
2124 insns to compute the value.
2126 The nodes of that expression have been freed by now, so we cannot use them.
2127 But we don't want to do that anyway; the expression has already been
2128 evaluated and now we just want to use the value. So generate a RTL_EXPR
2129 with the proper type and RTL value.
2131 If the last substatement was not an expression,
2132 return something with type `void'. */
2135 expand_end_stmt_expr (t)
2140 if (last_expr_type == 0)
2142 last_expr_type = void_type_node;
2143 last_expr_value = const0_rtx;
2145 else if (last_expr_value == 0)
2146 /* There are some cases where this can happen, such as when the
2147 statement is void type. */
2148 last_expr_value = const0_rtx;
2149 else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
2150 /* Remove any possible QUEUED. */
2151 last_expr_value = protect_from_queue (last_expr_value, 0);
2155 TREE_TYPE (t) = last_expr_type;
2156 RTL_EXPR_RTL (t) = last_expr_value;
2157 RTL_EXPR_SEQUENCE (t) = get_insns ();
2159 rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);
2163 /* Don't consider deleting this expr or containing exprs at tree level. */
2164 TREE_SIDE_EFFECTS (t) = 1;
2165 /* Propagate volatility of the actual RTL expr. */
2166 TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);
2169 expr_stmts_for_value--;
2174 /* Generate RTL for the start of an if-then. COND is the expression
2175 whose truth should be tested.
2177 If EXITFLAG is nonzero, this conditional is visible to
2178 `exit_something'. */
2181 expand_start_cond (cond, exitflag)
2185 struct nesting *thiscond = ALLOC_NESTING ();
2187 /* Make an entry on cond_stack for the cond we are entering. */
2189 thiscond->next = cond_stack;
2190 thiscond->all = nesting_stack;
2191 thiscond->depth = ++nesting_depth;
2192 thiscond->data.cond.next_label = gen_label_rtx ();
2193 /* Before we encounter an `else', we don't need a separate exit label
2194 unless there are supposed to be exit statements
2195 to exit this conditional. */
2196 thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
2197 thiscond->data.cond.endif_label = thiscond->exit_label;
2198 cond_stack = thiscond;
2199 nesting_stack = thiscond;
2201 do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
2204 /* Generate RTL between then-clause and the elseif-clause
2205 of an if-then-elseif-.... */
2208 expand_start_elseif (cond)
2211 if (cond_stack->data.cond.endif_label == 0)
2212 cond_stack->data.cond.endif_label = gen_label_rtx ();
2213 emit_jump (cond_stack->data.cond.endif_label);
2214 emit_label (cond_stack->data.cond.next_label);
2215 cond_stack->data.cond.next_label = gen_label_rtx ();
2216 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2219 /* Generate RTL between the then-clause and the else-clause
2220 of an if-then-else. */
2223 expand_start_else ()
2225 if (cond_stack->data.cond.endif_label == 0)
2226 cond_stack->data.cond.endif_label = gen_label_rtx ();
2228 emit_jump (cond_stack->data.cond.endif_label);
2229 emit_label (cond_stack->data.cond.next_label);
2230 cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */
2233 /* After calling expand_start_else, turn this "else" into an "else if"
2234 by providing another condition. */
2237 expand_elseif (cond)
2240 cond_stack->data.cond.next_label = gen_label_rtx ();
2241 do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
2244 /* Generate RTL for the end of an if-then.
2245 Pop the record for it off of cond_stack. */
2250 struct nesting *thiscond = cond_stack;
2252 do_pending_stack_adjust ();
2253 if (thiscond->data.cond.next_label)
2254 emit_label (thiscond->data.cond.next_label);
2255 if (thiscond->data.cond.endif_label)
2256 emit_label (thiscond->data.cond.endif_label);
2258 POPSTACK (cond_stack);
2262 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
2263 loop should be exited by `exit_something'. This is a loop for which
2264 `expand_continue' will jump to the top of the loop.
2266 Make an entry on loop_stack to record the labels associated with
2270 expand_start_loop (exit_flag)
2273 register struct nesting *thisloop = ALLOC_NESTING ();
2275 /* Make an entry on loop_stack for the loop we are entering. */
2277 thisloop->next = loop_stack;
2278 thisloop->all = nesting_stack;
2279 thisloop->depth = ++nesting_depth;
2280 thisloop->data.loop.start_label = gen_label_rtx ();
2281 thisloop->data.loop.end_label = gen_label_rtx ();
2282 thisloop->data.loop.alt_end_label = 0;
2283 thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
2284 thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
2285 loop_stack = thisloop;
2286 nesting_stack = thisloop;
2288 do_pending_stack_adjust ();
2290 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
2291 emit_label (thisloop->data.loop.start_label);
2296 /* Like expand_start_loop but for a loop where the continuation point
2297 (for expand_continue_loop) will be specified explicitly. */
2300 expand_start_loop_continue_elsewhere (exit_flag)
2303 struct nesting *thisloop = expand_start_loop (exit_flag);
2304 loop_stack->data.loop.continue_label = gen_label_rtx ();
2308 /* Begin a null, aka do { } while (0) "loop". But since the contents
2309 of said loop can still contain a break, we must frob the loop nest. */
2312 expand_start_null_loop ()
2314 register struct nesting *thisloop = ALLOC_NESTING ();
2316 /* Make an entry on loop_stack for the loop we are entering. */
2318 thisloop->next = loop_stack;
2319 thisloop->all = nesting_stack;
2320 thisloop->depth = ++nesting_depth;
2321 thisloop->data.loop.start_label = emit_note (NULL, NOTE_INSN_DELETED);
2322 thisloop->data.loop.end_label = gen_label_rtx ();
2323 thisloop->data.loop.alt_end_label = NULL_RTX;
2324 thisloop->data.loop.continue_label = thisloop->data.loop.end_label;
2325 thisloop->exit_label = thisloop->data.loop.end_label;
2326 loop_stack = thisloop;
2327 nesting_stack = thisloop;
2332 /* Specify the continuation point for a loop started with
2333 expand_start_loop_continue_elsewhere.
2334 Use this at the point in the code to which a continue statement
2338 expand_loop_continue_here ()
2340 do_pending_stack_adjust ();
2341 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
2342 emit_label (loop_stack->data.loop.continue_label);
2345 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2346 Pop the block off of loop_stack. */
2351 rtx start_label = loop_stack->data.loop.start_label;
2352 rtx insn = get_last_insn ();
2353 int needs_end_jump = 1;
2355 /* Mark the continue-point at the top of the loop if none elsewhere. */
2356 if (start_label == loop_stack->data.loop.continue_label)
2357 emit_note_before (NOTE_INSN_LOOP_CONT, start_label);
2359 do_pending_stack_adjust ();
2361 /* If optimizing, perhaps reorder the loop.
2362 First, try to use a condjump near the end.
2363 expand_exit_loop_if_false ends loops with unconditional jumps,
2366 if (test) goto label;
2368 goto loop_stack->data.loop.end_label
2372 If we find such a pattern, we can end the loop earlier. */
2375 && GET_CODE (insn) == CODE_LABEL
2376 && LABEL_NAME (insn) == NULL
2377 && GET_CODE (PREV_INSN (insn)) == BARRIER)
2380 rtx jump = PREV_INSN (PREV_INSN (label));
2382 if (GET_CODE (jump) == JUMP_INSN
2383 && GET_CODE (PATTERN (jump)) == SET
2384 && SET_DEST (PATTERN (jump)) == pc_rtx
2385 && GET_CODE (SET_SRC (PATTERN (jump))) == LABEL_REF
2386 && (XEXP (SET_SRC (PATTERN (jump)), 0)
2387 == loop_stack->data.loop.end_label))
2391 /* The test might be complex and reference LABEL multiple times,
2392 like the loop in loop_iterations to set vtop. To handle this,
2394 insn = PREV_INSN (label);
2395 reorder_insns (label, label, start_label);
2397 for (prev = PREV_INSN (jump);; prev = PREV_INSN (prev))
2399 /* We ignore line number notes, but if we see any other note,
2400 in particular NOTE_INSN_BLOCK_*, NOTE_INSN_EH_REGION_*,
2401 NOTE_INSN_LOOP_*, we disable this optimization. */
2402 if (GET_CODE (prev) == NOTE)
2404 if (NOTE_LINE_NUMBER (prev) < 0)
2408 if (GET_CODE (prev) == CODE_LABEL)
2410 if (GET_CODE (prev) == JUMP_INSN)
2412 if (GET_CODE (PATTERN (prev)) == SET
2413 && SET_DEST (PATTERN (prev)) == pc_rtx
2414 && GET_CODE (SET_SRC (PATTERN (prev))) == IF_THEN_ELSE
2415 && (GET_CODE (XEXP (SET_SRC (PATTERN (prev)), 1))
2417 && XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0) == label)
2419 XEXP (XEXP (SET_SRC (PATTERN (prev)), 1), 0)
2421 emit_note_after (NOTE_INSN_LOOP_END, prev);
2430 /* If the loop starts with a loop exit, roll that to the end where
2431 it will optimize together with the jump back.
2433 We look for the conditional branch to the exit, except that once
2434 we find such a branch, we don't look past 30 instructions.
2436 In more detail, if the loop presently looks like this (in pseudo-C):
2439 if (test) goto end_label;
2444 transform it to look like:
2450 if (test) goto end_label;
2451 goto newstart_label;
2454 Here, the `test' may actually consist of some reasonably complex
2455 code, terminating in a test. */
2460 ! (GET_CODE (insn) == JUMP_INSN
2461 && GET_CODE (PATTERN (insn)) == SET
2462 && SET_DEST (PATTERN (insn)) == pc_rtx
2463 && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE))
2467 rtx last_test_insn = NULL_RTX;
2469 /* Scan insns from the top of the loop looking for a qualified
2470 conditional exit. */
2471 for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn;
2472 insn = NEXT_INSN (insn))
2474 if (GET_CODE (insn) == NOTE)
2477 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2478 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2479 /* The code that actually moves the exit test will
2480 carefully leave BLOCK notes in their original
2481 location. That means, however, that we can't debug
2482 the exit test itself. So, we refuse to move code
2483 containing BLOCK notes at low optimization levels. */
2486 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
2488 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
2492 /* We've come to the end of an EH region, but
2493 never saw the beginning of that region. That
2494 means that an EH region begins before the top
2495 of the loop, and ends in the middle of it. The
2496 existence of such a situation violates a basic
2497 assumption in this code, since that would imply
2498 that even when EH_REGIONS is zero, we might
2499 move code out of an exception region. */
2503 /* We must not walk into a nested loop. */
2504 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
2507 /* We already know this INSN is a NOTE, so there's no
2508 point in looking at it to see if it's a JUMP. */
2512 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN)
2515 if (last_test_insn && num_insns > 30)
2519 /* We don't want to move a partial EH region. Consider:
2533 This isn't legal C++, but here's what it's supposed to
2534 mean: if cond() is true, stop looping. Otherwise,
2535 call bar, and keep looping. In addition, if cond
2536 throws an exception, catch it and keep looping. Such
2537 constructs are certainy legal in LISP.
2539 We should not move the `if (cond()) 0' test since then
2540 the EH-region for the try-block would be broken up.
2541 (In this case we would the EH_BEG note for the `try'
2542 and `if cond()' but not the call to bar() or the
2545 So we don't look for tests within an EH region. */
2548 if (GET_CODE (insn) == JUMP_INSN
2549 && GET_CODE (PATTERN (insn)) == SET
2550 && SET_DEST (PATTERN (insn)) == pc_rtx)
2552 /* This is indeed a jump. */
2553 rtx dest1 = NULL_RTX;
2554 rtx dest2 = NULL_RTX;
2555 rtx potential_last_test;
2556 if (GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)
2558 /* A conditional jump. */
2559 dest1 = XEXP (SET_SRC (PATTERN (insn)), 1);
2560 dest2 = XEXP (SET_SRC (PATTERN (insn)), 2);
2561 potential_last_test = insn;
2565 /* An unconditional jump. */
2566 dest1 = SET_SRC (PATTERN (insn));
2567 /* Include the BARRIER after the JUMP. */
2568 potential_last_test = NEXT_INSN (insn);
2572 if (dest1 && GET_CODE (dest1) == LABEL_REF
2573 && ((XEXP (dest1, 0)
2574 == loop_stack->data.loop.alt_end_label)
2576 == loop_stack->data.loop.end_label)))
2578 last_test_insn = potential_last_test;
2582 /* If this was a conditional jump, there may be
2583 another label at which we should look. */
2590 if (last_test_insn != 0 && last_test_insn != get_last_insn ())
2592 /* We found one. Move everything from there up
2593 to the end of the loop, and add a jump into the loop
2594 to jump to there. */
2595 register rtx newstart_label = gen_label_rtx ();
2596 register rtx start_move = start_label;
2599 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2600 then we want to move this note also. */
2601 if (GET_CODE (PREV_INSN (start_move)) == NOTE
2602 && (NOTE_LINE_NUMBER (PREV_INSN (start_move))
2603 == NOTE_INSN_LOOP_CONT))
2604 start_move = PREV_INSN (start_move);
2606 emit_label_after (newstart_label, PREV_INSN (start_move));
2608 /* Actually move the insns. Start at the beginning, and
2609 keep copying insns until we've copied the
2611 for (insn = start_move; insn; insn = next_insn)
2613 /* Figure out which insn comes after this one. We have
2614 to do this before we move INSN. */
2615 if (insn == last_test_insn)
2616 /* We've moved all the insns. */
2617 next_insn = NULL_RTX;
2619 next_insn = NEXT_INSN (insn);
2621 if (GET_CODE (insn) == NOTE
2622 && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
2623 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
2624 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2625 NOTE_INSN_BLOCK_ENDs because the correct generation
2626 of debugging information depends on these appearing
2627 in the same order in the RTL and in the tree
2628 structure, where they are represented as BLOCKs.
2629 So, we don't move block notes. Of course, moving
2630 the code inside the block is likely to make it
2631 impossible to debug the instructions in the exit
2632 test, but such is the price of optimization. */
2635 /* Move the INSN. */
2636 reorder_insns (insn, insn, get_last_insn ());
2639 emit_jump_insn_after (gen_jump (start_label),
2640 PREV_INSN (newstart_label));
2641 emit_barrier_after (PREV_INSN (newstart_label));
2642 start_label = newstart_label;
2648 emit_jump (start_label);
2649 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
2651 emit_label (loop_stack->data.loop.end_label);
2653 POPSTACK (loop_stack);
2658 /* Finish a null loop, aka do { } while (0). */
2661 expand_end_null_loop ()
2663 do_pending_stack_adjust ();
2664 emit_label (loop_stack->data.loop.end_label);
2666 POPSTACK (loop_stack);
2671 /* Generate a jump to the current loop's continue-point.
2672 This is usually the top of the loop, but may be specified
2673 explicitly elsewhere. If not currently inside a loop,
2674 return 0 and do nothing; caller will print an error message. */
2677 expand_continue_loop (whichloop)
2678 struct nesting *whichloop;
2682 whichloop = loop_stack;
2685 expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
2690 /* Generate a jump to exit the current loop. If not currently inside a loop,
2691 return 0 and do nothing; caller will print an error message. */
2694 expand_exit_loop (whichloop)
2695 struct nesting *whichloop;
2699 whichloop = loop_stack;
2702 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
2706 /* Generate a conditional jump to exit the current loop if COND
2707 evaluates to zero. If not currently inside a loop,
2708 return 0 and do nothing; caller will print an error message. */
2711 expand_exit_loop_if_false (whichloop, cond)
2712 struct nesting *whichloop;
2715 rtx label = gen_label_rtx ();
2720 whichloop = loop_stack;
2723 /* In order to handle fixups, we actually create a conditional jump
2724 around a unconditional branch to exit the loop. If fixups are
2725 necessary, they go before the unconditional branch. */
2727 do_jump (cond, NULL_RTX, label);
2728 last_insn = get_last_insn ();
2729 if (GET_CODE (last_insn) == CODE_LABEL)
2730 whichloop->data.loop.alt_end_label = last_insn;
2731 expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
2738 /* Return nonzero if the loop nest is empty. Else return zero. */
2741 stmt_loop_nest_empty ()
2743 /* cfun->stmt can be NULL if we are building a call to get the
2744 EH context for a setjmp/longjmp EH target and the current
2745 function was a deferred inline function. */
2746 return (cfun->stmt == NULL || loop_stack == NULL);
2749 /* Return non-zero if we should preserve sub-expressions as separate
2750 pseudos. We never do so if we aren't optimizing. We always do so
2751 if -fexpensive-optimizations.
2753 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2754 the loop may still be a small one. */
2757 preserve_subexpressions_p ()
2761 if (flag_expensive_optimizations)
2764 if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
2767 insn = get_last_insn_anywhere ();
2770 && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
2771 < n_non_fixed_regs * 3));
2775 /* Generate a jump to exit the current loop, conditional, binding contour
2776 or case statement. Not all such constructs are visible to this function,
2777 only those started with EXIT_FLAG nonzero. Individual languages use
2778 the EXIT_FLAG parameter to control which kinds of constructs you can
2781 If not currently inside anything that can be exited,
2782 return 0 and do nothing; caller will print an error message. */
2785 expand_exit_something ()
2789 for (n = nesting_stack; n; n = n->all)
2790 if (n->exit_label != 0)
2792 expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
2799 /* Generate RTL to return from the current function, with no value.
2800 (That is, we do not do anything about returning any value.) */
2803 expand_null_return ()
2805 struct nesting *block = block_stack;
2806 rtx last_insn = get_last_insn ();
2808 /* If this function was declared to return a value, but we
2809 didn't, clobber the return registers so that they are not
2810 propogated live to the rest of the function. */
2811 clobber_return_register ();
2813 /* Does any pending block have cleanups? */
2814 while (block && block->data.block.cleanups == 0)
2815 block = block->next;
2817 /* If yes, use a goto to return, since that runs cleanups. */
2819 expand_null_return_1 (last_insn, block != 0);
2822 /* Generate RTL to return from the current function, with value VAL. */
2825 expand_value_return (val)
2828 struct nesting *block = block_stack;
2829 rtx last_insn = get_last_insn ();
2830 rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl));
2832 /* Copy the value to the return location
2833 unless it's already there. */
2835 if (return_reg != val)
2837 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
2838 #ifdef PROMOTE_FUNCTION_RETURN
2839 int unsignedp = TREE_UNSIGNED (type);
2840 enum machine_mode old_mode
2841 = DECL_MODE (DECL_RESULT (current_function_decl));
2842 enum machine_mode mode
2843 = promote_mode (type, old_mode, &unsignedp, 1);
2845 if (mode != old_mode)
2846 val = convert_modes (mode, old_mode, val, unsignedp);
2848 if (GET_CODE (return_reg) == PARALLEL)
2849 emit_group_load (return_reg, val, int_size_in_bytes (type),
2852 emit_move_insn (return_reg, val);
2855 /* Does any pending block have cleanups? */
2857 while (block && block->data.block.cleanups == 0)
2858 block = block->next;
2860 /* If yes, use a goto to return, since that runs cleanups.
2861 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2863 expand_null_return_1 (last_insn, block != 0);
2866 /* Output a return with no value. If LAST_INSN is nonzero,
2867 pretend that the return takes place after LAST_INSN.
2868 If USE_GOTO is nonzero then don't use a return instruction;
2869 go to the return label instead. This causes any cleanups
2870 of pending blocks to be executed normally. */
2873 expand_null_return_1 (last_insn, use_goto)
2877 rtx end_label = cleanup_label ? cleanup_label : return_label;
2879 clear_pending_stack_adjust ();
2880 do_pending_stack_adjust ();
2883 /* PCC-struct return always uses an epilogue. */
2884 if (current_function_returns_pcc_struct || use_goto)
2887 end_label = return_label = gen_label_rtx ();
2888 expand_goto_internal (NULL_TREE, end_label, last_insn);
2892 /* Otherwise output a simple return-insn if one is available,
2893 unless it won't do the job. */
2895 if (HAVE_return && use_goto == 0 && cleanup_label == 0)
2897 emit_jump_insn (gen_return ());
2903 /* Otherwise jump to the epilogue. */
2904 expand_goto_internal (NULL_TREE, end_label, last_insn);
2907 /* Generate RTL to evaluate the expression RETVAL and return it
2908 from the current function. */
2911 expand_return (retval)
2914 /* If there are any cleanups to be performed, then they will
2915 be inserted following LAST_INSN. It is desirable
2916 that the last_insn, for such purposes, should be the
2917 last insn before computing the return value. Otherwise, cleanups
2918 which call functions can clobber the return value. */
2919 /* ??? rms: I think that is erroneous, because in C++ it would
2920 run destructors on variables that might be used in the subsequent
2921 computation of the return value. */
2923 rtx result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
2924 register rtx val = 0;
2928 /* If function wants no value, give it none. */
2929 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
2931 expand_expr (retval, NULL_RTX, VOIDmode, 0);
2933 expand_null_return ();
2937 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2938 /* This is not sufficient. We also need to watch for cleanups of the
2939 expression we are about to expand. Unfortunately, we cannot know
2940 if it has cleanups until we expand it, and we want to change how we
2941 expand it depending upon if we need cleanups. We can't win. */
2943 cleanups = any_pending_cleanups (1);
2948 if (retval == error_mark_node)
2950 /* Treat this like a return of no value from a function that
2952 expand_null_return ();
2955 else if (TREE_CODE (retval) == RESULT_DECL)
2956 retval_rhs = retval;
2957 else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
2958 && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
2959 retval_rhs = TREE_OPERAND (retval, 1);
2960 else if (VOID_TYPE_P (TREE_TYPE (retval)))
2961 /* Recognize tail-recursive call to void function. */
2962 retval_rhs = retval;
2964 retval_rhs = NULL_TREE;
2966 /* Only use `last_insn' if there are cleanups which must be run. */
2967 if (cleanups || cleanup_label != 0)
2968 last_insn = get_last_insn ();
2970 /* Distribute return down conditional expr if either of the sides
2971 may involve tail recursion (see test below). This enhances the number
2972 of tail recursions we see. Don't do this always since it can produce
2973 sub-optimal code in some cases and we distribute assignments into
2974 conditional expressions when it would help. */
2976 if (optimize && retval_rhs != 0
2977 && frame_offset == 0
2978 && TREE_CODE (retval_rhs) == COND_EXPR
2979 && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
2980 || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
2982 rtx label = gen_label_rtx ();
2985 do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
2986 start_cleanup_deferral ();
2987 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2988 DECL_RESULT (current_function_decl),
2989 TREE_OPERAND (retval_rhs, 1));
2990 TREE_SIDE_EFFECTS (expr) = 1;
2991 expand_return (expr);
2994 expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
2995 DECL_RESULT (current_function_decl),
2996 TREE_OPERAND (retval_rhs, 2));
2997 TREE_SIDE_EFFECTS (expr) = 1;
2998 expand_return (expr);
2999 end_cleanup_deferral ();
3003 /* If the result is an aggregate that is being returned in one (or more)
3004 registers, load the registers here. The compiler currently can't handle
3005 copying a BLKmode value into registers. We could put this code in a
3006 more general area (for use by everyone instead of just function
3007 call/return), but until this feature is generally usable it is kept here
3008 (and in expand_call). The value must go into a pseudo in case there
3009 are cleanups that will clobber the real return register. */
3012 && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
3013 && GET_CODE (result_rtl) == REG)
3016 unsigned HOST_WIDE_INT bitpos, xbitpos;
3017 unsigned HOST_WIDE_INT big_endian_correction = 0;
3018 unsigned HOST_WIDE_INT bytes
3019 = int_size_in_bytes (TREE_TYPE (retval_rhs));
3020 int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
3021 unsigned int bitsize
3022 = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
3023 rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs);
3024 rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
3025 rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
3026 enum machine_mode tmpmode, result_reg_mode;
3030 expand_null_return ();
3034 /* Structures whose size is not a multiple of a word are aligned
3035 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
3036 machine, this means we must skip the empty high order bytes when
3037 calculating the bit offset. */
3038 if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD)
3039 big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
3042 /* Copy the structure BITSIZE bits at a time. */
3043 for (bitpos = 0, xbitpos = big_endian_correction;
3044 bitpos < bytes * BITS_PER_UNIT;
3045 bitpos += bitsize, xbitpos += bitsize)
3047 /* We need a new destination pseudo each time xbitpos is
3048 on a word boundary and when xbitpos == big_endian_correction
3049 (the first time through). */
3050 if (xbitpos % BITS_PER_WORD == 0
3051 || xbitpos == big_endian_correction)
3053 /* Generate an appropriate register. */
3054 dst = gen_reg_rtx (word_mode);
3055 result_pseudos[xbitpos / BITS_PER_WORD] = dst;
3057 /* Clobber the destination before we move anything into it. */
3058 emit_insn (gen_rtx_CLOBBER (VOIDmode, dst));
3061 /* We need a new source operand each time bitpos is on a word
3063 if (bitpos % BITS_PER_WORD == 0)
3064 src = operand_subword_force (result_val,
3065 bitpos / BITS_PER_WORD,
3068 /* Use bitpos for the source extraction (left justified) and
3069 xbitpos for the destination store (right justified). */
3070 store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
3071 extract_bit_field (src, bitsize,
3072 bitpos % BITS_PER_WORD, 1,
3073 NULL_RTX, word_mode, word_mode,
3074 bitsize, BITS_PER_WORD),
3075 bitsize, BITS_PER_WORD);
3078 /* Find the smallest integer mode large enough to hold the
3079 entire structure and use that mode instead of BLKmode
3080 on the USE insn for the return register. */
3081 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3082 tmpmode != VOIDmode;
3083 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
3084 /* Have we found a large enough mode? */
3085 if (GET_MODE_SIZE (tmpmode) >= bytes)
3088 /* No suitable mode found. */
3089 if (tmpmode == VOIDmode)
3092 PUT_MODE (result_rtl, tmpmode);
3094 if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
3095 result_reg_mode = word_mode;
3097 result_reg_mode = tmpmode;
3098 result_reg = gen_reg_rtx (result_reg_mode);
3101 for (i = 0; i < n_regs; i++)
3102 emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
3105 if (tmpmode != result_reg_mode)
3106 result_reg = gen_lowpart (tmpmode, result_reg);
3108 expand_value_return (result_reg);
3112 && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
3113 && (GET_CODE (result_rtl) == REG
3114 || (GET_CODE (result_rtl) == PARALLEL)))
3116 /* Calculate the return value into a temporary (usually a pseudo
3118 tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
3119 tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
3121 val = assign_temp (nt, 0, 0, 1);
3122 val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
3123 val = force_not_mem (val);
3125 /* Return the calculated value, doing cleanups first. */
3126 expand_value_return (val);
3130 /* No cleanups or no hard reg used;
3131 calculate value into hard return reg. */
3132 expand_expr (retval, const0_rtx, VOIDmode, 0);
3134 expand_value_return (result_rtl);
3138 /* Return 1 if the end of the generated RTX is not a barrier.
3139 This means code already compiled can drop through. */
3142 drop_through_at_end_p ()
3144 rtx insn = get_last_insn ();
3145 while (insn && GET_CODE (insn) == NOTE)
3146 insn = PREV_INSN (insn);
3147 return insn && GET_CODE (insn) != BARRIER;
3150 /* Attempt to optimize a potential tail recursion call into a goto.
3151 ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
3152 where to place the jump to the tail recursion label.
3154 Return TRUE if the call was optimized into a goto. */
3157 optimize_tail_recursion (arguments, last_insn)
3161 /* Finish checking validity, and if valid emit code to set the
3162 argument variables for the new call. */
3163 if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
3165 if (tail_recursion_label == 0)
3167 tail_recursion_label = gen_label_rtx ();
3168 emit_label_after (tail_recursion_label,
3169 tail_recursion_reentry);
3172 expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
3179 /* Emit code to alter this function's formal parms for a tail-recursive call.
3180 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
3181 FORMALS is the chain of decls of formals.
3182 Return 1 if this can be done;
3183 otherwise return 0 and do not emit any code. */
3186 tail_recursion_args (actuals, formals)
3187 tree actuals, formals;
3189 register tree a = actuals, f = formals;
3191 register rtx *argvec;
3193 /* Check that number and types of actuals are compatible
3194 with the formals. This is not always true in valid C code.
3195 Also check that no formal needs to be addressable
3196 and that all formals are scalars. */
3198 /* Also count the args. */
3200 for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
3202 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a)))
3203 != TYPE_MAIN_VARIANT (TREE_TYPE (f)))
3205 if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
3208 if (a != 0 || f != 0)
3211 /* Compute all the actuals. */
3213 argvec = (rtx *) alloca (i * sizeof (rtx));
3215 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3216 argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);
3218 /* Find which actual values refer to current values of previous formals.
3219 Copy each of them now, before any formal is changed. */
3221 for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
3225 for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
3226 if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
3232 argvec[i] = copy_to_reg (argvec[i]);
3235 /* Store the values of the actuals into the formals. */
3237 for (f = formals, a = actuals, i = 0; f;
3238 f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
3240 if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
3241 emit_move_insn (DECL_RTL (f), argvec[i]);
3243 convert_move (DECL_RTL (f), argvec[i],
3244 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a))));
3251 /* Generate the RTL code for entering a binding contour.
3252 The variables are declared one by one, by calls to `expand_decl'.
3254 FLAGS is a bitwise or of the following flags:
3256 1 - Nonzero if this construct should be visible to
3259 2 - Nonzero if this contour does not require a
3260 NOTE_INSN_BLOCK_BEG note. Virtually all calls from
3261 language-independent code should set this flag because they
3262 will not create corresponding BLOCK nodes. (There should be
3263 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
3264 and BLOCKs.) If this flag is set, MARK_ENDS should be zero
3265 when expand_end_bindings is called.
3267 If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
3268 optionally be supplied. If so, it becomes the NOTE_BLOCK for the
3272 expand_start_bindings_and_block (flags, block)
3276 struct nesting *thisblock = ALLOC_NESTING ();
3278 int exit_flag = ((flags & 1) != 0);
3279 int block_flag = ((flags & 2) == 0);
3281 /* If a BLOCK is supplied, then the caller should be requesting a
3282 NOTE_INSN_BLOCK_BEG note. */
3283 if (!block_flag && block)
3286 /* Create a note to mark the beginning of the block. */
3289 note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG);
3290 NOTE_BLOCK (note) = block;
3293 note = emit_note (NULL_PTR, NOTE_INSN_DELETED);
3295 /* Make an entry on block_stack for the block we are entering. */
3297 thisblock->next = block_stack;
3298 thisblock->all = nesting_stack;
3299 thisblock->depth = ++nesting_depth;
3300 thisblock->data.block.stack_level = 0;
3301 thisblock->data.block.cleanups = 0;
3302 thisblock->data.block.n_function_calls = 0;
3303 thisblock->data.block.exception_region = 0;
3304 thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;
3306 thisblock->data.block.conditional_code = 0;
3307 thisblock->data.block.last_unconditional_cleanup = note;
3308 /* When we insert instructions after the last unconditional cleanup,
3309 we don't adjust last_insn. That means that a later add_insn will
3310 clobber the instructions we've just added. The easiest way to
3311 fix this is to just insert another instruction here, so that the
3312 instructions inserted after the last unconditional cleanup are
3313 never the last instruction. */
3314 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3315 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
3318 && !(block_stack->data.block.cleanups == NULL_TREE
3319 && block_stack->data.block.outer_cleanups == NULL_TREE))
3320 thisblock->data.block.outer_cleanups
3321 = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
3322 block_stack->data.block.outer_cleanups);
3324 thisblock->data.block.outer_cleanups = 0;
3325 thisblock->data.block.label_chain = 0;
3326 thisblock->data.block.innermost_stack_block = stack_block_stack;
3327 thisblock->data.block.first_insn = note;
3328 thisblock->data.block.block_start_count = ++current_block_start_count;
3329 thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
3330 block_stack = thisblock;
3331 nesting_stack = thisblock;
3333 /* Make a new level for allocating stack slots. */
3337 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
3338 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
3339 expand_expr are made. After we end the region, we know that all
3340 space for all temporaries that were created by TARGET_EXPRs will be
3341 destroyed and their space freed for reuse. */
3344 expand_start_target_temps ()
3346 /* This is so that even if the result is preserved, the space
3347 allocated will be freed, as we know that it is no longer in use. */
3350 /* Start a new binding layer that will keep track of all cleanup
3351 actions to be performed. */
3352 expand_start_bindings (2);
3354 target_temp_slot_level = temp_slot_level;
3358 expand_end_target_temps ()
3360 expand_end_bindings (NULL_TREE, 0, 0);
3362 /* This is so that even if the result is preserved, the space
3363 allocated will be freed, as we know that it is no longer in use. */
3367 /* Given a pointer to a BLOCK node return non-zero if (and only if) the node
3368 in question represents the outermost pair of curly braces (i.e. the "body
3369 block") of a function or method.
3371 For any BLOCK node representing a "body block" of a function or method, the
3372 BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
3373 represents the outermost (function) scope for the function or method (i.e.
3374 the one which includes the formal parameters). The BLOCK_SUPERCONTEXT of
3375 *that* node in turn will point to the relevant FUNCTION_DECL node. */
3378 is_body_block (stmt)
3381 if (TREE_CODE (stmt) == BLOCK)
3383 tree parent = BLOCK_SUPERCONTEXT (stmt);
3385 if (parent && TREE_CODE (parent) == BLOCK)
3387 tree grandparent = BLOCK_SUPERCONTEXT (parent);
3389 if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
3397 /* Mark top block of block_stack as an implicit binding for an
3398 exception region. This is used to prevent infinite recursion when
3399 ending a binding with expand_end_bindings. It is only ever called
3400 by expand_eh_region_start, as that it the only way to create a
3401 block stack for a exception region. */
3404 mark_block_as_eh_region ()
3406 block_stack->data.block.exception_region = 1;
3407 if (block_stack->next
3408 && block_stack->next->data.block.conditional_code)
3410 block_stack->data.block.conditional_code
3411 = block_stack->next->data.block.conditional_code;
3412 block_stack->data.block.last_unconditional_cleanup
3413 = block_stack->next->data.block.last_unconditional_cleanup;
3414 block_stack->data.block.cleanup_ptr
3415 = block_stack->next->data.block.cleanup_ptr;
3419 /* True if we are currently emitting insns in an area of output code
3420 that is controlled by a conditional expression. This is used by
3421 the cleanup handling code to generate conditional cleanup actions. */
3424 conditional_context ()
3426 return block_stack && block_stack->data.block.conditional_code;
3429 /* Mark top block of block_stack as not for an implicit binding for an
3430 exception region. This is only ever done by expand_eh_region_end
3431 to let expand_end_bindings know that it is being called explicitly
3432 to end the binding layer for just the binding layer associated with
3433 the exception region, otherwise expand_end_bindings would try and
3434 end all implicit binding layers for exceptions regions, and then
3435 one normal binding layer. */
3438 mark_block_as_not_eh_region ()
3440 block_stack->data.block.exception_region = 0;
3443 /* True if the top block of block_stack was marked as for an exception
3444 region by mark_block_as_eh_region. */
3449 return cfun && block_stack && block_stack->data.block.exception_region;
3452 /* Emit a handler label for a nonlocal goto handler.
3453 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3456 expand_nl_handler_label (slot, before_insn)
3457 rtx slot, before_insn;
3460 rtx handler_label = gen_label_rtx ();
3462 /* Don't let jump_optimize delete the handler. */
3463 LABEL_PRESERVE_P (handler_label) = 1;
3466 emit_move_insn (slot, gen_rtx_LABEL_REF (Pmode, handler_label));
3467 insns = get_insns ();
3469 emit_insns_before (insns, before_insn);
3471 emit_label (handler_label);
3473 return handler_label;
3476 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3479 expand_nl_goto_receiver ()
3481 #ifdef HAVE_nonlocal_goto
3482 if (! HAVE_nonlocal_goto)
3484 /* First adjust our frame pointer to its actual value. It was
3485 previously set to the start of the virtual area corresponding to
3486 the stacked variables when we branched here and now needs to be
3487 adjusted to the actual hardware fp value.
3489 Assignments are to virtual registers are converted by
3490 instantiate_virtual_regs into the corresponding assignment
3491 to the underlying register (fp in this case) that makes
3492 the original assignment true.
3493 So the following insn will actually be
3494 decrementing fp by STARTING_FRAME_OFFSET. */
3495 emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
3497 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3498 if (fixed_regs[ARG_POINTER_REGNUM])
3500 #ifdef ELIMINABLE_REGS
3501 /* If the argument pointer can be eliminated in favor of the
3502 frame pointer, we don't need to restore it. We assume here
3503 that if such an elimination is present, it can always be used.
3504 This is the case on all known machines; if we don't make this
3505 assumption, we do unnecessary saving on many machines. */
3506 static struct elims {int from, to;} elim_regs[] = ELIMINABLE_REGS;
3509 for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
3510 if (elim_regs[i].from == ARG_POINTER_REGNUM
3511 && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
3514 if (i == ARRAY_SIZE (elim_regs))
3517 /* Now restore our arg pointer from the address at which it
3518 was saved in our stack frame.
3519 If there hasn't be space allocated for it yet, make
3521 if (arg_pointer_save_area == 0)
3522 arg_pointer_save_area
3523 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
3524 emit_move_insn (virtual_incoming_args_rtx,
3525 /* We need a pseudo here, or else
3526 instantiate_virtual_regs_1 complains. */
3527 copy_to_reg (arg_pointer_save_area));
3532 #ifdef HAVE_nonlocal_goto_receiver
3533 if (HAVE_nonlocal_goto_receiver)
3534 emit_insn (gen_nonlocal_goto_receiver ());
3538 /* Make handlers for nonlocal gotos taking place in the function calls in
3542 expand_nl_goto_receivers (thisblock)
3543 struct nesting *thisblock;
3546 rtx afterward = gen_label_rtx ();
3551 /* Record the handler address in the stack slot for that purpose,
3552 during this block, saving and restoring the outer value. */
3553 if (thisblock->next != 0)
3554 for (slot = nonlocal_goto_handler_slots; slot; slot = XEXP (slot, 1))
3556 rtx save_receiver = gen_reg_rtx (Pmode);
3557 emit_move_insn (XEXP (slot, 0), save_receiver);
3560 emit_move_insn (save_receiver, XEXP (slot, 0));
3561 insns = get_insns ();
3563 emit_insns_before (insns, thisblock->data.block.first_insn);
3566 /* Jump around the handlers; they run only when specially invoked. */
3567 emit_jump (afterward);
3569 /* Make a separate handler for each label. */
3570 link = nonlocal_labels;
3571 slot = nonlocal_goto_handler_slots;
3572 label_list = NULL_RTX;
3573 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3574 /* Skip any labels we shouldn't be able to jump to from here,
3575 we generate one special handler for all of them below which just calls
3577 if (! DECL_TOO_LATE (TREE_VALUE (link)))
3580 lab = expand_nl_handler_label (XEXP (slot, 0),
3581 thisblock->data.block.first_insn);
3582 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3584 expand_nl_goto_receiver ();
3586 /* Jump to the "real" nonlocal label. */
3587 expand_goto (TREE_VALUE (link));
3590 /* A second pass over all nonlocal labels; this time we handle those
3591 we should not be able to jump to at this point. */
3592 link = nonlocal_labels;
3593 slot = nonlocal_goto_handler_slots;
3595 for (; link; link = TREE_CHAIN (link), slot = XEXP (slot, 1))
3596 if (DECL_TOO_LATE (TREE_VALUE (link)))
3599 lab = expand_nl_handler_label (XEXP (slot, 0),
3600 thisblock->data.block.first_insn);
3601 label_list = gen_rtx_EXPR_LIST (VOIDmode, lab, label_list);
3607 expand_nl_goto_receiver ();
3608 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "abort"), 0,
3613 nonlocal_goto_handler_labels = label_list;
3614 emit_label (afterward);
3617 /* Warn about any unused VARS (which may contain nodes other than
3618 VAR_DECLs, but such nodes are ignored). The nodes are connected
3619 via the TREE_CHAIN field. */
3622 warn_about_unused_variables (vars)
3627 if (warn_unused_variable)
3628 for (decl = vars; decl; decl = TREE_CHAIN (decl))
3629 if (TREE_CODE (decl) == VAR_DECL
3630 && ! TREE_USED (decl)
3631 && ! DECL_IN_SYSTEM_HEADER (decl)
3632 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
3633 warning_with_decl (decl, "unused variable `%s'");
3636 /* Generate RTL code to terminate a binding contour.
3638 VARS is the chain of VAR_DECL nodes for the variables bound in this
3639 contour. There may actually be other nodes in this chain, but any
3640 nodes other than VAR_DECLS are ignored.
3642 MARK_ENDS is nonzero if we should put a note at the beginning
3643 and end of this binding contour.
3645 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3646 (That is true automatically if the contour has a saved stack level.) */
3649 expand_end_bindings (vars, mark_ends, dont_jump_in)
3654 register struct nesting *thisblock;
3656 while (block_stack->data.block.exception_region)
3658 /* Because we don't need or want a new temporary level and
3659 because we didn't create one in expand_eh_region_start,
3660 create a fake one now to avoid removing one in
3661 expand_end_bindings. */
3664 block_stack->data.block.exception_region = 0;
3666 expand_end_bindings (NULL_TREE, 0, 0);
3669 /* Since expand_eh_region_start does an expand_start_bindings, we
3670 have to first end all the bindings that were created by
3671 expand_eh_region_start. */
3673 thisblock = block_stack;
3675 /* If any of the variables in this scope were not used, warn the
3677 warn_about_unused_variables (vars);
3679 if (thisblock->exit_label)
3681 do_pending_stack_adjust ();
3682 emit_label (thisblock->exit_label);
3685 /* If necessary, make handlers for nonlocal gotos taking
3686 place in the function calls in this block. */
3687 if (function_call_count != thisblock->data.block.n_function_calls
3689 /* Make handler for outermost block
3690 if there were any nonlocal gotos to this function. */
3691 && (thisblock->next == 0 ? current_function_has_nonlocal_label
3692 /* Make handler for inner block if it has something
3693 special to do when you jump out of it. */
3694 : (thisblock->data.block.cleanups != 0
3695 || thisblock->data.block.stack_level != 0)))
3696 expand_nl_goto_receivers (thisblock);
3698 /* Don't allow jumping into a block that has a stack level.
3699 Cleanups are allowed, though. */
3701 || thisblock->data.block.stack_level != 0)
3703 struct label_chain *chain;
3705 /* Any labels in this block are no longer valid to go to.
3706 Mark them to cause an error message. */
3707 for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
3709 DECL_TOO_LATE (chain->label) = 1;
3710 /* If any goto without a fixup came to this label,
3711 that must be an error, because gotos without fixups
3712 come from outside all saved stack-levels. */
3713 if (TREE_ADDRESSABLE (chain->label))
3714 error_with_decl (chain->label,
3715 "label `%s' used before containing binding contour");
3719 /* Restore stack level in effect before the block
3720 (only if variable-size objects allocated). */
3721 /* Perform any cleanups associated with the block. */
3723 if (thisblock->data.block.stack_level != 0
3724 || thisblock->data.block.cleanups != 0)
3729 /* Don't let cleanups affect ({...}) constructs. */
3730 int old_expr_stmts_for_value = expr_stmts_for_value;
3731 rtx old_last_expr_value = last_expr_value;
3732 tree old_last_expr_type = last_expr_type;
3733 expr_stmts_for_value = 0;
3735 /* Only clean up here if this point can actually be reached. */
3736 insn = get_last_insn ();
3737 if (GET_CODE (insn) == NOTE)
3738 insn = prev_nonnote_insn (insn);
3739 reachable = (! insn || GET_CODE (insn) != BARRIER);
3741 /* Do the cleanups. */
3742 expand_cleanups (thisblock->data.block.cleanups, NULL_TREE, 0, reachable);
3744 do_pending_stack_adjust ();
3746 expr_stmts_for_value = old_expr_stmts_for_value;
3747 last_expr_value = old_last_expr_value;
3748 last_expr_type = old_last_expr_type;
3750 /* Restore the stack level. */
3752 if (reachable && thisblock->data.block.stack_level != 0)
3754 emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3755 thisblock->data.block.stack_level, NULL_RTX);
3756 if (nonlocal_goto_handler_slots != 0)
3757 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level,
3761 /* Any gotos out of this block must also do these things.
3762 Also report any gotos with fixups that came to labels in this
3764 fixup_gotos (thisblock,
3765 thisblock->data.block.stack_level,
3766 thisblock->data.block.cleanups,
3767 thisblock->data.block.first_insn,
3771 /* Mark the beginning and end of the scope if requested.
3772 We do this now, after running cleanups on the variables
3773 just going out of scope, so they are in scope for their cleanups. */
3777 rtx note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END);
3778 NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
3781 /* Get rid of the beginning-mark if we don't make an end-mark. */
3782 NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;
3784 /* Restore the temporary level of TARGET_EXPRs. */
3785 target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;
3787 /* Restore block_stack level for containing block. */
3789 stack_block_stack = thisblock->data.block.innermost_stack_block;
3790 POPSTACK (block_stack);
3792 /* Pop the stack slot nesting and free any slots at this level. */
3796 /* Generate code to save the stack pointer at the start of the current block
3797 and set up to restore it on exit. */
3800 save_stack_pointer ()
3802 struct nesting *thisblock = block_stack;
3804 if (thisblock->data.block.stack_level == 0)
3806 emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
3807 &thisblock->data.block.stack_level,
3808 thisblock->data.block.first_insn);
3809 stack_block_stack = thisblock;
3813 /* Generate RTL for the automatic variable declaration DECL.
3814 (Other kinds of declarations are simply ignored if seen here.) */
3820 struct nesting *thisblock;
3823 type = TREE_TYPE (decl);
3825 /* Only automatic variables need any expansion done.
3826 Static and external variables, and external functions,
3827 will be handled by `assemble_variable' (called from finish_decl).
3828 TYPE_DECL and CONST_DECL require nothing.
3829 PARM_DECLs are handled in `assign_parms'. */
3831 if (TREE_CODE (decl) != VAR_DECL)
3833 if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
3836 thisblock = block_stack;
3838 /* Create the RTL representation for the variable. */
3840 if (type == error_mark_node)
3841 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3843 else if (DECL_SIZE (decl) == 0)
3844 /* Variable with incomplete type. */
3846 if (DECL_INITIAL (decl) == 0)
3847 /* Error message was already done; now avoid a crash. */
3848 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, const0_rtx);
3850 /* An initializer is going to decide the size of this array.
3851 Until we know the size, represent its address with a reg. */
3852 DECL_RTL (decl) = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));
3854 set_mem_attributes (DECL_RTL (decl), decl, 1);
3856 else if (DECL_MODE (decl) != BLKmode
3857 /* If -ffloat-store, don't put explicit float vars
3859 && !(flag_float_store
3860 && TREE_CODE (type) == REAL_TYPE)
3861 && ! TREE_THIS_VOLATILE (decl)
3862 && (DECL_REGISTER (decl) || optimize)
3863 /* if -fcheck-memory-usage, check all variables. */
3864 && ! current_function_check_memory_usage)
3866 /* Automatic variable that can go in a register. */
3867 int unsignedp = TREE_UNSIGNED (type);
3868 enum machine_mode reg_mode
3869 = promote_mode (type, DECL_MODE (decl), &unsignedp, 0);
3871 DECL_RTL (decl) = gen_reg_rtx (reg_mode);
3872 mark_user_reg (DECL_RTL (decl));
3874 if (POINTER_TYPE_P (type))
3875 mark_reg_pointer (DECL_RTL (decl),
3876 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
3878 maybe_set_unchanging (DECL_RTL (decl), decl);
3880 /* If something wants our address, try to use ADDRESSOF. */
3881 if (TREE_ADDRESSABLE (decl))
3882 put_var_into_stack (decl);
3885 else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
3886 && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
3887 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
3888 STACK_CHECK_MAX_VAR_SIZE)))
3890 /* Variable of fixed size that goes on the stack. */
3894 /* If we previously made RTL for this decl, it must be an array
3895 whose size was determined by the initializer.
3896 The old address was a register; set that register now
3897 to the proper address. */
3898 if (DECL_RTL (decl) != 0)
3900 if (GET_CODE (DECL_RTL (decl)) != MEM
3901 || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
3903 oldaddr = XEXP (DECL_RTL (decl), 0);
3906 DECL_RTL (decl) = assign_temp (TREE_TYPE (decl), 1, 1, 1);
3908 /* Set alignment we actually gave this decl. */
3909 DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
3910 : GET_MODE_BITSIZE (DECL_MODE (decl)));
3911 DECL_USER_ALIGN (decl) = 0;
3915 addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
3916 if (addr != oldaddr)
3917 emit_move_insn (oldaddr, addr);
3921 /* Dynamic-size object: must push space on the stack. */
3925 /* Record the stack pointer on entry to block, if have
3926 not already done so. */
3927 do_pending_stack_adjust ();
3928 save_stack_pointer ();
3930 /* In function-at-a-time mode, variable_size doesn't expand this,
3932 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
3933 expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
3934 const0_rtx, VOIDmode, 0);
3936 /* Compute the variable's size, in bytes. */
3937 size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
3940 /* Allocate space on the stack for the variable. Note that
3941 DECL_ALIGN says how the variable is to be aligned and we
3942 cannot use it to conclude anything about the alignment of
3944 address = allocate_dynamic_stack_space (size, NULL_RTX,
3945 TYPE_ALIGN (TREE_TYPE (decl)));
3947 /* Reference the variable indirect through that rtx. */
3948 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl), address);
3950 set_mem_attributes (DECL_RTL (decl), decl, 1);
3952 /* Indicate the alignment we actually gave this variable. */
3953 #ifdef STACK_BOUNDARY
3954 DECL_ALIGN (decl) = STACK_BOUNDARY;
3956 DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
3958 DECL_USER_ALIGN (decl) = 0;
3962 /* Emit code to perform the initialization of a declaration DECL. */
3965 expand_decl_init (decl)
3968 int was_used = TREE_USED (decl);
3970 /* If this is a CONST_DECL, we don't have to generate any code, but
3971 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3972 to be set while in the obstack containing the constant. If we don't
3973 do this, we can lose if we have functions nested three deep and the middle
3974 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3975 the innermost function is the first to expand that STRING_CST. */
3976 if (TREE_CODE (decl) == CONST_DECL)
3978 if (DECL_INITIAL (decl) && TREE_CONSTANT (DECL_INITIAL (decl)))
3979 expand_expr (DECL_INITIAL (decl), NULL_RTX, VOIDmode,
3980 EXPAND_INITIALIZER);
3984 if (TREE_STATIC (decl))
3987 /* Compute and store the initial value now. */
3989 if (DECL_INITIAL (decl) == error_mark_node)
3991 enum tree_code code = TREE_CODE (TREE_TYPE (decl));
3993 if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
3994 || code == POINTER_TYPE || code == REFERENCE_TYPE)
3995 expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
3999 else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
4001 emit_line_note (DECL_SOURCE_FILE (decl), DECL_SOURCE_LINE (decl));
4002 expand_assignment (decl, DECL_INITIAL (decl), 0, 0);
4006 /* Don't let the initialization count as "using" the variable. */
4007 TREE_USED (decl) = was_used;
4009 /* Free any temporaries we made while initializing the decl. */
4010 preserve_temp_slots (NULL_RTX);
4014 /* CLEANUP is an expression to be executed at exit from this binding contour;
4015 for example, in C++, it might call the destructor for this variable.
4017 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
4018 CLEANUP multiple times, and have the correct semantics. This
4019 happens in exception handling, for gotos, returns, breaks that
4020 leave the current scope.
4022 If CLEANUP is nonzero and DECL is zero, we record a cleanup
4023 that is not associated with any particular variable. */
4026 expand_decl_cleanup (decl, cleanup)
4029 struct nesting *thisblock;
4031 /* Error if we are not in any block. */
4032 if (cfun == 0 || block_stack == 0)
4035 thisblock = block_stack;
4037 /* Record the cleanup if there is one. */
4043 tree *cleanups = &thisblock->data.block.cleanups;
4044 int cond_context = conditional_context ();
4048 rtx flag = gen_reg_rtx (word_mode);
4053 emit_move_insn (flag, const0_rtx);
4054 set_flag_0 = get_insns ();
4057 thisblock->data.block.last_unconditional_cleanup
4058 = emit_insns_after (set_flag_0,
4059 thisblock->data.block.last_unconditional_cleanup);
4061 emit_move_insn (flag, const1_rtx);
4063 cond = build_decl (VAR_DECL, NULL_TREE, type_for_mode (word_mode, 1));
4064 DECL_RTL (cond) = flag;
4066 /* Conditionalize the cleanup. */
4067 cleanup = build (COND_EXPR, void_type_node,
4068 truthvalue_conversion (cond),
4069 cleanup, integer_zero_node);
4070 cleanup = fold (cleanup);
4072 cleanups = thisblock->data.block.cleanup_ptr;
4075 cleanup = unsave_expr (cleanup);
4077 t = *cleanups = tree_cons (decl, cleanup, *cleanups);
4080 /* If this block has a cleanup, it belongs in stack_block_stack. */
4081 stack_block_stack = thisblock;
4088 /* If this was optimized so that there is no exception region for the
4089 cleanup, then mark the TREE_LIST node, so that we can later tell
4090 if we need to call expand_eh_region_end. */
4091 if (! using_eh_for_cleanups_p
4092 || expand_eh_region_start_tree (decl, cleanup))
4093 TREE_ADDRESSABLE (t) = 1;
4094 /* If that started a new EH region, we're in a new block. */
4095 thisblock = block_stack;
4102 thisblock->data.block.last_unconditional_cleanup
4103 = emit_insns_after (seq,
4104 thisblock->data.block.last_unconditional_cleanup);
4108 thisblock->data.block.last_unconditional_cleanup
4110 /* When we insert instructions after the last unconditional cleanup,
4111 we don't adjust last_insn. That means that a later add_insn will
4112 clobber the instructions we've just added. The easiest way to
4113 fix this is to just insert another instruction here, so that the
4114 instructions inserted after the last unconditional cleanup are
4115 never the last instruction. */
4116 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4117 thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups;
4123 /* Like expand_decl_cleanup, but suppress generating an exception handler
4124 to perform the cleanup. */
4128 expand_decl_cleanup_no_eh (decl, cleanup)
4131 int save_eh = using_eh_for_cleanups_p;
4134 using_eh_for_cleanups_p = 0;
4135 result = expand_decl_cleanup (decl, cleanup);
4136 using_eh_for_cleanups_p = save_eh;
4142 /* Arrange for the top element of the dynamic cleanup chain to be
4143 popped if we exit the current binding contour. DECL is the
4144 associated declaration, if any, otherwise NULL_TREE. If the
4145 current contour is left via an exception, then __sjthrow will pop
4146 the top element off the dynamic cleanup chain. The code that
4147 avoids doing the action we push into the cleanup chain in the
4148 exceptional case is contained in expand_cleanups.
4150 This routine is only used by expand_eh_region_start, and that is
4151 the only way in which an exception region should be started. This
4152 routine is only used when using the setjmp/longjmp codegen method
4153 for exception handling. */
4156 expand_dcc_cleanup (decl)
4159 struct nesting *thisblock;
4162 /* Error if we are not in any block. */
4163 if (cfun == 0 || block_stack == 0)
4165 thisblock = block_stack;
4167 /* Record the cleanup for the dynamic handler chain. */
4169 cleanup = make_node (POPDCC_EXPR);
4171 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4172 thisblock->data.block.cleanups
4173 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4175 /* If this block has a cleanup, it belongs in stack_block_stack. */
4176 stack_block_stack = thisblock;
4180 /* Arrange for the top element of the dynamic handler chain to be
4181 popped if we exit the current binding contour. DECL is the
4182 associated declaration, if any, otherwise NULL_TREE. If the current
4183 contour is left via an exception, then __sjthrow will pop the top
4184 element off the dynamic handler chain. The code that avoids doing
4185 the action we push into the handler chain in the exceptional case
4186 is contained in expand_cleanups.
4188 This routine is only used by expand_eh_region_start, and that is
4189 the only way in which an exception region should be started. This
4190 routine is only used when using the setjmp/longjmp codegen method
4191 for exception handling. */
4194 expand_dhc_cleanup (decl)
4197 struct nesting *thisblock;
4200 /* Error if we are not in any block. */
4201 if (cfun == 0 || block_stack == 0)
4203 thisblock = block_stack;
4205 /* Record the cleanup for the dynamic handler chain. */
4207 cleanup = make_node (POPDHC_EXPR);
4209 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
4210 thisblock->data.block.cleanups
4211 = tree_cons (decl, cleanup, thisblock->data.block.cleanups);
4213 /* If this block has a cleanup, it belongs in stack_block_stack. */
4214 stack_block_stack = thisblock;
4218 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
4219 DECL_ELTS is the list of elements that belong to DECL's type.
4220 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
4223 expand_anon_union_decl (decl, cleanup, decl_elts)
4224 tree decl, cleanup, decl_elts;
4226 struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
4230 /* If any of the elements are addressable, so is the entire union. */
4231 for (t = decl_elts; t; t = TREE_CHAIN (t))
4232 if (TREE_ADDRESSABLE (TREE_VALUE (t)))
4234 TREE_ADDRESSABLE (decl) = 1;
4239 expand_decl_cleanup (decl, cleanup);
4240 x = DECL_RTL (decl);
4242 /* Go through the elements, assigning RTL to each. */
4243 for (t = decl_elts; t; t = TREE_CHAIN (t))
4245 tree decl_elt = TREE_VALUE (t);
4246 tree cleanup_elt = TREE_PURPOSE (t);
4247 enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));
4249 /* Propagate the union's alignment to the elements. */
4250 DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
4251 DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);
4253 /* If the element has BLKmode and the union doesn't, the union is
4254 aligned such that the element doesn't need to have BLKmode, so
4255 change the element's mode to the appropriate one for its size. */
4256 if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
4257 DECL_MODE (decl_elt) = mode
4258 = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);
4260 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
4261 instead create a new MEM rtx with the proper mode. */
4262 if (GET_CODE (x) == MEM)
4264 if (mode == GET_MODE (x))
4265 DECL_RTL (decl_elt) = x;
4268 DECL_RTL (decl_elt) = gen_rtx_MEM (mode, copy_rtx (XEXP (x, 0)));
4269 MEM_COPY_ATTRIBUTES (DECL_RTL (decl_elt), x);
4272 else if (GET_CODE (x) == REG)
4274 if (mode == GET_MODE (x))
4275 DECL_RTL (decl_elt) = x;
4277 DECL_RTL (decl_elt) = gen_rtx_SUBREG (mode, x, 0);
4282 /* Record the cleanup if there is one. */
4285 thisblock->data.block.cleanups
4286 = tree_cons (decl_elt, cleanup_elt,
4287 thisblock->data.block.cleanups);
4291 /* Expand a list of cleanups LIST.
4292 Elements may be expressions or may be nested lists.
4294 If DONT_DO is nonnull, then any list-element
4295 whose TREE_PURPOSE matches DONT_DO is omitted.
4296 This is sometimes used to avoid a cleanup associated with
4297 a value that is being returned out of the scope.
4299 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
4300 goto and handle protection regions specially in that case.
4302 If REACHABLE, we emit code, otherwise just inform the exception handling
4303 code about this finalization. */
4306 expand_cleanups (list, dont_do, in_fixup, reachable)
4313 for (tail = list; tail; tail = TREE_CHAIN (tail))
4314 if (dont_do == 0 || TREE_PURPOSE (tail) != dont_do)
4316 if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
4317 expand_cleanups (TREE_VALUE (tail), dont_do, in_fixup, reachable);
4322 tree cleanup = TREE_VALUE (tail);
4324 /* See expand_d{h,c}c_cleanup for why we avoid this. */
4325 if (TREE_CODE (cleanup) != POPDHC_EXPR
4326 && TREE_CODE (cleanup) != POPDCC_EXPR
4327 /* See expand_eh_region_start_tree for this case. */
4328 && ! TREE_ADDRESSABLE (tail))
4330 cleanup = protect_with_terminate (cleanup);
4331 expand_eh_region_end (cleanup);
4337 /* Cleanups may be run multiple times. For example,
4338 when exiting a binding contour, we expand the
4339 cleanups associated with that contour. When a goto
4340 within that binding contour has a target outside that
4341 contour, it will expand all cleanups from its scope to
4342 the target. Though the cleanups are expanded multiple
4343 times, the control paths are non-overlapping so the
4344 cleanups will not be executed twice. */
4346 /* We may need to protect fixups with rethrow regions. */
4347 int protect = (in_fixup && ! TREE_ADDRESSABLE (tail));
4350 expand_fixup_region_start ();
4352 /* The cleanup might contain try-blocks, so we have to
4353 preserve our current queue. */
4355 expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);
4358 expand_fixup_region_end (TREE_VALUE (tail));
4365 /* Mark when the context we are emitting RTL for as a conditional
4366 context, so that any cleanup actions we register with
4367 expand_decl_init will be properly conditionalized when those
4368 cleanup actions are later performed. Must be called before any
4369 expression (tree) is expanded that is within a conditional context. */
4372 start_cleanup_deferral ()
4374 /* block_stack can be NULL if we are inside the parameter list. It is
4375 OK to do nothing, because cleanups aren't possible here. */
4377 ++block_stack->data.block.conditional_code;
4380 /* Mark the end of a conditional region of code. Because cleanup
4381 deferrals may be nested, we may still be in a conditional region
4382 after we end the currently deferred cleanups, only after we end all
4383 deferred cleanups, are we back in unconditional code. */
4386 end_cleanup_deferral ()
4388 /* block_stack can be NULL if we are inside the parameter list. It is
4389 OK to do nothing, because cleanups aren't possible here. */
4391 --block_stack->data.block.conditional_code;
4394 /* Move all cleanups from the current block_stack
4395 to the containing block_stack, where they are assumed to
4396 have been created. If anything can cause a temporary to
4397 be created, but not expanded for more than one level of
4398 block_stacks, then this code will have to change. */
4403 struct nesting *block = block_stack;
4404 struct nesting *outer = block->next;
4406 outer->data.block.cleanups
4407 = chainon (block->data.block.cleanups,
4408 outer->data.block.cleanups);
4409 block->data.block.cleanups = 0;
4413 last_cleanup_this_contour ()
4415 if (block_stack == 0)
4418 return block_stack->data.block.cleanups;
4421 /* Return 1 if there are any pending cleanups at this point.
4422 If THIS_CONTOUR is nonzero, check the current contour as well.
4423 Otherwise, look only at the contours that enclose this one. */
4426 any_pending_cleanups (this_contour)
4429 struct nesting *block;
4431 if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
4434 if (this_contour && block_stack->data.block.cleanups != NULL)
4436 if (block_stack->data.block.cleanups == 0
4437 && block_stack->data.block.outer_cleanups == 0)
4440 for (block = block_stack->next; block; block = block->next)
4441 if (block->data.block.cleanups != 0)
4447 /* Enter a case (Pascal) or switch (C) statement.
4448 Push a block onto case_stack and nesting_stack
4449 to accumulate the case-labels that are seen
4450 and to record the labels generated for the statement.
4452 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4453 Otherwise, this construct is transparent for `exit_something'.
4455 EXPR is the index-expression to be dispatched on.
4456 TYPE is its nominal type. We could simply convert EXPR to this type,
4457 but instead we take short cuts. */
4460 expand_start_case (exit_flag, expr, type, printname)
4464 const char *printname;
4466 register struct nesting *thiscase = ALLOC_NESTING ();
4468 /* Make an entry on case_stack for the case we are entering. */
4470 thiscase->next = case_stack;
4471 thiscase->all = nesting_stack;
4472 thiscase->depth = ++nesting_depth;
4473 thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
4474 thiscase->data.case_stmt.case_list = 0;
4475 thiscase->data.case_stmt.index_expr = expr;
4476 thiscase->data.case_stmt.nominal_type = type;
4477 thiscase->data.case_stmt.default_label = 0;
4478 thiscase->data.case_stmt.printname = printname;
4479 thiscase->data.case_stmt.line_number_status = force_line_numbers ();
4480 case_stack = thiscase;
4481 nesting_stack = thiscase;
4483 do_pending_stack_adjust ();
4485 /* Make sure case_stmt.start points to something that won't
4486 need any transformation before expand_end_case. */
4487 if (GET_CODE (get_last_insn ()) != NOTE)
4488 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4490 thiscase->data.case_stmt.start = get_last_insn ();
4492 start_cleanup_deferral ();
4495 /* Start a "dummy case statement" within which case labels are invalid
4496 and are not connected to any larger real case statement.
4497 This can be used if you don't want to let a case statement jump
4498 into the middle of certain kinds of constructs. */
4501 expand_start_case_dummy ()
4503 register struct nesting *thiscase = ALLOC_NESTING ();
4505 /* Make an entry on case_stack for the dummy. */
4507 thiscase->next = case_stack;
4508 thiscase->all = nesting_stack;
4509 thiscase->depth = ++nesting_depth;
4510 thiscase->exit_label = 0;
4511 thiscase->data.case_stmt.case_list = 0;
4512 thiscase->data.case_stmt.start = 0;
4513 thiscase->data.case_stmt.nominal_type = 0;
4514 thiscase->data.case_stmt.default_label = 0;
4515 case_stack = thiscase;
4516 nesting_stack = thiscase;
4517 start_cleanup_deferral ();
4520 /* End a dummy case statement. */
4523 expand_end_case_dummy ()
4525 end_cleanup_deferral ();
4526 POPSTACK (case_stack);
4529 /* Return the data type of the index-expression
4530 of the innermost case statement, or null if none. */
4533 case_index_expr_type ()
4536 return TREE_TYPE (case_stack->data.case_stmt.index_expr);
4543 /* If this is the first label, warn if any insns have been emitted. */
4544 if (case_stack->data.case_stmt.line_number_status >= 0)
4548 restore_line_number_status
4549 (case_stack->data.case_stmt.line_number_status);
4550 case_stack->data.case_stmt.line_number_status = -1;
4552 for (insn = case_stack->data.case_stmt.start;
4554 insn = NEXT_INSN (insn))
4556 if (GET_CODE (insn) == CODE_LABEL)
4558 if (GET_CODE (insn) != NOTE
4559 && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
4562 insn = PREV_INSN (insn);
4563 while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));
4565 /* If insn is zero, then there must have been a syntax error. */
4567 warning_with_file_and_line (NOTE_SOURCE_FILE (insn),
4568 NOTE_LINE_NUMBER (insn),
4569 "unreachable code at beginning of %s",
4570 case_stack->data.case_stmt.printname);
4577 /* Accumulate one case or default label inside a case or switch statement.
4578 VALUE is the value of the case (a null pointer, for a default label).
4579 The function CONVERTER, when applied to arguments T and V,
4580 converts the value V to the type T.
4582 If not currently inside a case or switch statement, return 1 and do
4583 nothing. The caller will print a language-specific error message.
4584 If VALUE is a duplicate or overlaps, return 2 and do nothing
4585 except store the (first) duplicate node in *DUPLICATE.
4586 If VALUE is out of range, return 3 and do nothing.
4587 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4588 Return 0 on success.
4590 Extended to handle range statements. */
4593 pushcase (value, converter, label, duplicate)
4594 register tree value;
4595 tree (*converter) PARAMS ((tree, tree));
4596 register tree label;
4602 /* Fail if not inside a real case statement. */
4603 if (! (case_stack && case_stack->data.case_stmt.start))
4606 if (stack_block_stack
4607 && stack_block_stack->depth > case_stack->depth)
4610 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4611 nominal_type = case_stack->data.case_stmt.nominal_type;
4613 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4614 if (index_type == error_mark_node)
4617 /* Convert VALUE to the type in which the comparisons are nominally done. */
4619 value = (*converter) (nominal_type, value);
4623 /* Fail if this value is out of range for the actual type of the index
4624 (which may be narrower than NOMINAL_TYPE). */
4626 && (TREE_CONSTANT_OVERFLOW (value)
4627 || ! int_fits_type_p (value, index_type)))
4630 return add_case_node (value, value, label, duplicate);
4633 /* Like pushcase but this case applies to all values between VALUE1 and
4634 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4635 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4636 starts at VALUE1 and ends at the highest value of the index type.
4637 If both are NULL, this case applies to all values.
4639 The return value is the same as that of pushcase but there is one
4640 additional error code: 4 means the specified range was empty. */
4643 pushcase_range (value1, value2, converter, label, duplicate)
4644 register tree value1, value2;
4645 tree (*converter) PARAMS ((tree, tree));
4646 register tree label;
4652 /* Fail if not inside a real case statement. */
4653 if (! (case_stack && case_stack->data.case_stmt.start))
4656 if (stack_block_stack
4657 && stack_block_stack->depth > case_stack->depth)
4660 index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
4661 nominal_type = case_stack->data.case_stmt.nominal_type;
4663 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4664 if (index_type == error_mark_node)
4669 /* Convert VALUEs to type in which the comparisons are nominally done
4670 and replace any unspecified value with the corresponding bound. */
4672 value1 = TYPE_MIN_VALUE (index_type);
4674 value2 = TYPE_MAX_VALUE (index_type);
4676 /* Fail if the range is empty. Do this before any conversion since
4677 we want to allow out-of-range empty ranges. */
4678 if (value2 != 0 && tree_int_cst_lt (value2, value1))
4681 /* If the max was unbounded, use the max of the nominal_type we are
4682 converting to. Do this after the < check above to suppress false
4685 value2 = TYPE_MAX_VALUE (nominal_type);
4687 value1 = (*converter) (nominal_type, value1);
4688 value2 = (*converter) (nominal_type, value2);
4690 /* Fail if these values are out of range. */
4691 if (TREE_CONSTANT_OVERFLOW (value1)
4692 || ! int_fits_type_p (value1, index_type))
4695 if (TREE_CONSTANT_OVERFLOW (value2)
4696 || ! int_fits_type_p (value2, index_type))
4699 return add_case_node (value1, value2, label, duplicate);
4702 /* Do the actual insertion of a case label for pushcase and pushcase_range
4703 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4704 slowdown for large switch statements. */
4707 add_case_node (low, high, label, duplicate)
4712 struct case_node *p, **q, *r;
4714 /* If there's no HIGH value, then this is not a case range; it's
4715 just a simple case label. But that's just a degenerate case
4720 /* Handle default labels specially. */
4723 if (case_stack->data.case_stmt.default_label != 0)
4725 *duplicate = case_stack->data.case_stmt.default_label;
4728 case_stack->data.case_stmt.default_label = label;
4729 expand_label (label);
4733 q = &case_stack->data.case_stmt.case_list;
4740 /* Keep going past elements distinctly greater than HIGH. */
4741 if (tree_int_cst_lt (high, p->low))
4744 /* or distinctly less than LOW. */
4745 else if (tree_int_cst_lt (p->high, low))
4750 /* We have an overlap; this is an error. */
4751 *duplicate = p->code_label;
4756 /* Add this label to the chain, and succeed. */
4758 r = (struct case_node *) xmalloc (sizeof (struct case_node));
4761 /* If the bounds are equal, turn this into the one-value case. */
4762 if (tree_int_cst_equal (low, high))
4767 r->code_label = label;
4768 expand_label (label);
4778 struct case_node *s;
4784 if (! (b = p->balance))
4785 /* Growth propagation from left side. */
4792 if ((p->left = s = r->right))
4801 if ((r->parent = s))
4809 case_stack->data.case_stmt.case_list = r;
4812 /* r->balance == +1 */
4817 struct case_node *t = r->right;
4819 if ((p->left = s = t->right))
4823 if ((r->right = s = t->left))
4837 if ((t->parent = s))
4845 case_stack->data.case_stmt.case_list = t;
4852 /* p->balance == +1; growth of left side balances the node. */
4862 if (! (b = p->balance))
4863 /* Growth propagation from right side. */
4871 if ((p->right = s = r->left))
4879 if ((r->parent = s))
4888 case_stack->data.case_stmt.case_list = r;
4892 /* r->balance == -1 */
4896 struct case_node *t = r->left;
4898 if ((p->right = s = t->left))
4903 if ((r->left = s = t->right))
4917 if ((t->parent = s))
4926 case_stack->data.case_stmt.case_list = t;
4932 /* p->balance == -1; growth of right side balances the node. */
4945 /* Returns the number of possible values of TYPE.
4946 Returns -1 if the number is unknown, variable, or if the number does not
4947 fit in a HOST_WIDE_INT.
4948 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4949 do not increase monotonically (there may be duplicates);
4950 to 1 if the values increase monotonically, but not always by 1;
4951 otherwise sets it to 0. */
4954 all_cases_count (type, spareness)
4959 HOST_WIDE_INT count, minval, lastval;
4963 switch (TREE_CODE (type))
4970 count = 1 << BITS_PER_UNIT;
4975 if (TYPE_MAX_VALUE (type) != 0
4976 && 0 != (t = fold (build (MINUS_EXPR, type, TYPE_MAX_VALUE (type),
4977 TYPE_MIN_VALUE (type))))
4978 && 0 != (t = fold (build (PLUS_EXPR, type, t,
4979 convert (type, integer_zero_node))))
4980 && host_integerp (t, 1))
4981 count = tree_low_cst (t, 1);
4987 /* Don't waste time with enumeral types with huge values. */
4988 if (! host_integerp (TYPE_MIN_VALUE (type), 0)
4989 || TYPE_MAX_VALUE (type) == 0
4990 || ! host_integerp (TYPE_MAX_VALUE (type), 0))
4993 lastval = minval = tree_low_cst (TYPE_MIN_VALUE (type), 0);
4996 for (t = TYPE_VALUES (type); t != NULL_TREE; t = TREE_CHAIN (t))
4998 HOST_WIDE_INT thisval = tree_low_cst (TREE_VALUE (t), 0);
5000 if (*spareness == 2 || thisval < lastval)
5002 else if (thisval != minval + count)
5012 #define BITARRAY_TEST(ARRAY, INDEX) \
5013 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5014 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
5015 #define BITARRAY_SET(ARRAY, INDEX) \
5016 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
5017 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
5019 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
5020 with the case values we have seen, assuming the case expression
5022 SPARSENESS is as determined by all_cases_count.
5024 The time needed is proportional to COUNT, unless
5025 SPARSENESS is 2, in which case quadratic time is needed. */
5028 mark_seen_cases (type, cases_seen, count, sparseness)
5030 unsigned char *cases_seen;
5031 HOST_WIDE_INT count;
5034 tree next_node_to_try = NULL_TREE;
5035 HOST_WIDE_INT next_node_offset = 0;
5037 register struct case_node *n, *root = case_stack->data.case_stmt.case_list;
5038 tree val = make_node (INTEGER_CST);
5040 TREE_TYPE (val) = type;
5044 else if (sparseness == 2)
5047 unsigned HOST_WIDE_INT xlo;
5049 /* This less efficient loop is only needed to handle
5050 duplicate case values (multiple enum constants
5051 with the same value). */
5052 TREE_TYPE (val) = TREE_TYPE (root->low);
5053 for (t = TYPE_VALUES (type), xlo = 0; t != NULL_TREE;
5054 t = TREE_CHAIN (t), xlo++)
5056 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (TREE_VALUE (t));
5057 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (TREE_VALUE (t));
5061 /* Keep going past elements distinctly greater than VAL. */
5062 if (tree_int_cst_lt (val, n->low))
5065 /* or distinctly less than VAL. */
5066 else if (tree_int_cst_lt (n->high, val))
5071 /* We have found a matching range. */
5072 BITARRAY_SET (cases_seen, xlo);
5082 case_stack->data.case_stmt.case_list = root = case_tree2list (root, 0);
5084 for (n = root; n; n = n->right)
5086 TREE_INT_CST_LOW (val) = TREE_INT_CST_LOW (n->low);
5087 TREE_INT_CST_HIGH (val) = TREE_INT_CST_HIGH (n->low);
5088 while (! tree_int_cst_lt (n->high, val))
5090 /* Calculate (into xlo) the "offset" of the integer (val).
5091 The element with lowest value has offset 0, the next smallest
5092 element has offset 1, etc. */
5094 unsigned HOST_WIDE_INT xlo;
5098 if (sparseness && TYPE_VALUES (type) != NULL_TREE)
5100 /* The TYPE_VALUES will be in increasing order, so
5101 starting searching where we last ended. */
5102 t = next_node_to_try;
5103 xlo = next_node_offset;
5109 t = TYPE_VALUES (type);
5112 if (tree_int_cst_equal (val, TREE_VALUE (t)))
5114 next_node_to_try = TREE_CHAIN (t);
5115 next_node_offset = xlo + 1;
5120 if (t == next_node_to_try)
5129 t = TYPE_MIN_VALUE (type);
5131 neg_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t),
5135 add_double (xlo, xhi,
5136 TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5140 if (xhi == 0 && xlo < (unsigned HOST_WIDE_INT) count)
5141 BITARRAY_SET (cases_seen, xlo);
5143 add_double (TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val),
5145 &TREE_INT_CST_LOW (val), &TREE_INT_CST_HIGH (val));
5151 /* Called when the index of a switch statement is an enumerated type
5152 and there is no default label.
5154 Checks that all enumeration literals are covered by the case
5155 expressions of a switch. Also, warn if there are any extra
5156 switch cases that are *not* elements of the enumerated type.
5158 If all enumeration literals were covered by the case expressions,
5159 turn one of the expressions into the default expression since it should
5160 not be possible to fall through such a switch. */
5163 check_for_full_enumeration_handling (type)
5166 register struct case_node *n;
5167 register tree chain;
5168 #if 0 /* variable used by 'if 0'ed code below. */
5169 register struct case_node **l;
5173 /* True iff the selector type is a numbered set mode. */
5176 /* The number of possible selector values. */
5179 /* For each possible selector value. a one iff it has been matched
5180 by a case value alternative. */
5181 unsigned char *cases_seen;
5183 /* The allocated size of cases_seen, in chars. */
5184 HOST_WIDE_INT bytes_needed;
5189 size = all_cases_count (type, &sparseness);
5190 bytes_needed = (size + HOST_BITS_PER_CHAR) / HOST_BITS_PER_CHAR;
5192 if (size > 0 && size < 600000
5193 /* We deliberately use calloc here, not cmalloc, so that we can suppress
5194 this optimization if we don't have enough memory rather than
5195 aborting, as xmalloc would do. */
5196 && (cases_seen = (unsigned char *) calloc (bytes_needed, 1)) != NULL)
5199 tree v = TYPE_VALUES (type);
5201 /* The time complexity of this code is normally O(N), where
5202 N being the number of members in the enumerated type.
5203 However, if type is a ENUMERAL_TYPE whose values do not
5204 increase monotonically, O(N*log(N)) time may be needed. */
5206 mark_seen_cases (type, cases_seen, size, sparseness);
5208 for (i = 0; v != NULL_TREE && i < size; i++, v = TREE_CHAIN (v))
5209 if (BITARRAY_TEST (cases_seen, i) == 0)
5210 warning ("enumeration value `%s' not handled in switch",
5211 IDENTIFIER_POINTER (TREE_PURPOSE (v)));
5216 /* Now we go the other way around; we warn if there are case
5217 expressions that don't correspond to enumerators. This can
5218 occur since C and C++ don't enforce type-checking of
5219 assignments to enumeration variables. */
5221 if (case_stack->data.case_stmt.case_list
5222 && case_stack->data.case_stmt.case_list->left)
5223 case_stack->data.case_stmt.case_list
5224 = case_tree2list (case_stack->data.case_stmt.case_list, 0);
5226 for (n = case_stack->data.case_stmt.case_list; n; n = n->right)
5228 for (chain = TYPE_VALUES (type);
5229 chain && !tree_int_cst_equal (n->low, TREE_VALUE (chain));
5230 chain = TREE_CHAIN (chain))
5235 if (TYPE_NAME (type) == 0)
5236 warning ("case value `%ld' not in enumerated type",
5237 (long) TREE_INT_CST_LOW (n->low));
5239 warning ("case value `%ld' not in enumerated type `%s'",
5240 (long) TREE_INT_CST_LOW (n->low),
5241 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5244 : DECL_NAME (TYPE_NAME (type))));
5246 if (!tree_int_cst_equal (n->low, n->high))
5248 for (chain = TYPE_VALUES (type);
5249 chain && !tree_int_cst_equal (n->high, TREE_VALUE (chain));
5250 chain = TREE_CHAIN (chain))
5255 if (TYPE_NAME (type) == 0)
5256 warning ("case value `%ld' not in enumerated type",
5257 (long) TREE_INT_CST_LOW (n->high));
5259 warning ("case value `%ld' not in enumerated type `%s'",
5260 (long) TREE_INT_CST_LOW (n->high),
5261 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type))
5264 : DECL_NAME (TYPE_NAME (type))));
5270 /* ??? This optimization is disabled because it causes valid programs to
5271 fail. ANSI C does not guarantee that an expression with enum type
5272 will have a value that is the same as one of the enumeration literals. */
5274 /* If all values were found as case labels, make one of them the default
5275 label. Thus, this switch will never fall through. We arbitrarily pick
5276 the last one to make the default since this is likely the most
5277 efficient choice. */
5281 for (l = &case_stack->data.case_stmt.case_list;
5286 case_stack->data.case_stmt.default_label = (*l)->code_label;
5292 /* Free CN, and its children. */
5295 free_case_nodes (cn)
5300 free_case_nodes (cn->left);
5301 free_case_nodes (cn->right);
5307 /* Terminate a case (Pascal) or switch (C) statement
5308 in which ORIG_INDEX is the expression to be tested.
5309 Generate the code to test it and jump to the right place. */
5312 expand_end_case (orig_index)
5315 tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE, orig_minval;
5316 rtx default_label = 0;
5317 register struct case_node *n;
5325 register struct nesting *thiscase = case_stack;
5326 tree index_expr, index_type;
5329 /* Don't crash due to previous errors. */
5330 if (thiscase == NULL)
5333 table_label = gen_label_rtx ();
5334 index_expr = thiscase->data.case_stmt.index_expr;
5335 index_type = TREE_TYPE (index_expr);
5336 unsignedp = TREE_UNSIGNED (index_type);
5338 do_pending_stack_adjust ();
5340 /* This might get an spurious warning in the presence of a syntax error;
5341 it could be fixed by moving the call to check_seenlabel after the
5342 check for error_mark_node, and copying the code of check_seenlabel that
5343 deals with case_stack->data.case_stmt.line_number_status /
5344 restore_line_number_status in front of the call to end_cleanup_deferral;
5345 However, this might miss some useful warnings in the presence of
5346 non-syntax errors. */
5349 /* An ERROR_MARK occurs for various reasons including invalid data type. */
5350 if (index_type != error_mark_node)
5352 /* If switch expression was an enumerated type, check that all
5353 enumeration literals are covered by the cases.
5354 No sense trying this if there's a default case, however. */
5356 if (!thiscase->data.case_stmt.default_label
5357 && TREE_CODE (TREE_TYPE (orig_index)) == ENUMERAL_TYPE
5358 && TREE_CODE (index_expr) != INTEGER_CST)
5359 check_for_full_enumeration_handling (TREE_TYPE (orig_index));
5361 /* If we don't have a default-label, create one here,
5362 after the body of the switch. */
5363 if (thiscase->data.case_stmt.default_label == 0)
5365 thiscase->data.case_stmt.default_label
5366 = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
5367 expand_label (thiscase->data.case_stmt.default_label);
5369 default_label = label_rtx (thiscase->data.case_stmt.default_label);
5371 before_case = get_last_insn ();
5373 if (thiscase->data.case_stmt.case_list
5374 && thiscase->data.case_stmt.case_list->left)
5375 thiscase->data.case_stmt.case_list
5376 = case_tree2list (thiscase->data.case_stmt.case_list, 0);
5378 /* Simplify the case-list before we count it. */
5379 group_case_nodes (thiscase->data.case_stmt.case_list);
5381 /* Get upper and lower bounds of case values.
5382 Also convert all the case values to the index expr's data type. */
5385 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5387 /* Check low and high label values are integers. */
5388 if (TREE_CODE (n->low) != INTEGER_CST)
5390 if (TREE_CODE (n->high) != INTEGER_CST)
5393 n->low = convert (index_type, n->low);
5394 n->high = convert (index_type, n->high);
5396 /* Count the elements and track the largest and smallest
5397 of them (treating them as signed even if they are not). */
5405 if (INT_CST_LT (n->low, minval))
5407 if (INT_CST_LT (maxval, n->high))
5410 /* A range counts double, since it requires two compares. */
5411 if (! tree_int_cst_equal (n->low, n->high))
5415 orig_minval = minval;
5417 /* Compute span of values. */
5419 range = fold (build (MINUS_EXPR, index_type, maxval, minval));
5421 end_cleanup_deferral ();
5425 expand_expr (index_expr, const0_rtx, VOIDmode, 0);
5427 emit_jump (default_label);
5430 /* If range of values is much bigger than number of values,
5431 make a sequence of conditional branches instead of a dispatch.
5432 If the switch-index is a constant, do it this way
5433 because we can optimize it. */
5435 #ifndef CASE_VALUES_THRESHOLD
5437 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5439 /* If machine does not have a case insn that compares the
5440 bounds, this means extra overhead for dispatch tables
5441 which raises the threshold for using them. */
5442 #define CASE_VALUES_THRESHOLD 5
5443 #endif /* HAVE_casesi */
5444 #endif /* CASE_VALUES_THRESHOLD */
5446 else if (count < CASE_VALUES_THRESHOLD
5447 || compare_tree_int (range, 10 * count) > 0
5448 /* RANGE may be signed, and really large ranges will show up
5449 as negative numbers. */
5450 || compare_tree_int (range, 0) < 0
5451 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5454 || TREE_CODE (index_expr) == INTEGER_CST
5455 /* These will reduce to a constant. */
5456 || (TREE_CODE (index_expr) == CALL_EXPR
5457 && TREE_CODE (TREE_OPERAND (index_expr, 0)) == ADDR_EXPR
5458 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == FUNCTION_DECL
5459 && DECL_BUILT_IN_CLASS (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_NORMAL
5460 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr, 0), 0)) == BUILT_IN_CLASSIFY_TYPE)
5461 || (TREE_CODE (index_expr) == COMPOUND_EXPR
5462 && TREE_CODE (TREE_OPERAND (index_expr, 1)) == INTEGER_CST))
5464 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5466 /* If the index is a short or char that we do not have
5467 an insn to handle comparisons directly, convert it to
5468 a full integer now, rather than letting each comparison
5469 generate the conversion. */
5471 if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
5472 && (cmp_optab->handlers[(int) GET_MODE (index)].insn_code
5473 == CODE_FOR_nothing))
5475 enum machine_mode wider_mode;
5476 for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
5477 wider_mode = GET_MODE_WIDER_MODE (wider_mode))
5478 if (cmp_optab->handlers[(int) wider_mode].insn_code
5479 != CODE_FOR_nothing)
5481 index = convert_to_mode (wider_mode, index, unsignedp);
5487 do_pending_stack_adjust ();
5489 index = protect_from_queue (index, 0);
5490 if (GET_CODE (index) == MEM)
5491 index = copy_to_reg (index);
5492 if (GET_CODE (index) == CONST_INT
5493 || TREE_CODE (index_expr) == INTEGER_CST)
5495 /* Make a tree node with the proper constant value
5496 if we don't already have one. */
5497 if (TREE_CODE (index_expr) != INTEGER_CST)
5500 = build_int_2 (INTVAL (index),
5501 unsignedp || INTVAL (index) >= 0 ? 0 : -1);
5502 index_expr = convert (index_type, index_expr);
5505 /* For constant index expressions we need only
5506 issue a unconditional branch to the appropriate
5507 target code. The job of removing any unreachable
5508 code is left to the optimisation phase if the
5509 "-O" option is specified. */
5510 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5511 if (! tree_int_cst_lt (index_expr, n->low)
5512 && ! tree_int_cst_lt (n->high, index_expr))
5516 emit_jump (label_rtx (n->code_label));
5518 emit_jump (default_label);
5522 /* If the index expression is not constant we generate
5523 a binary decision tree to select the appropriate
5524 target code. This is done as follows:
5526 The list of cases is rearranged into a binary tree,
5527 nearly optimal assuming equal probability for each case.
5529 The tree is transformed into RTL, eliminating
5530 redundant test conditions at the same time.
5532 If program flow could reach the end of the
5533 decision tree an unconditional jump to the
5534 default code is emitted. */
5537 = (TREE_CODE (TREE_TYPE (orig_index)) != ENUMERAL_TYPE
5538 && estimate_case_costs (thiscase->data.case_stmt.case_list));
5539 balance_case_nodes (&thiscase->data.case_stmt.case_list,
5541 emit_case_nodes (index, thiscase->data.case_stmt.case_list,
5542 default_label, index_type);
5543 emit_jump_if_reachable (default_label);
5552 enum machine_mode index_mode = SImode;
5553 int index_bits = GET_MODE_BITSIZE (index_mode);
5555 enum machine_mode op_mode;
5557 /* Convert the index to SImode. */
5558 if (GET_MODE_BITSIZE (TYPE_MODE (index_type))
5559 > GET_MODE_BITSIZE (index_mode))
5561 enum machine_mode omode = TYPE_MODE (index_type);
5562 rtx rangertx = expand_expr (range, NULL_RTX, VOIDmode, 0);
5564 /* We must handle the endpoints in the original mode. */
5565 index_expr = build (MINUS_EXPR, index_type,
5566 index_expr, minval);
5567 minval = integer_zero_node;
5568 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5569 emit_cmp_and_jump_insns (rangertx, index, LTU, NULL_RTX,
5570 omode, 1, 0, default_label);
5571 /* Now we can safely truncate. */
5572 index = convert_to_mode (index_mode, index, 0);
5576 if (TYPE_MODE (index_type) != index_mode)
5578 index_expr = convert (type_for_size (index_bits, 0),
5580 index_type = TREE_TYPE (index_expr);
5583 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5586 index = protect_from_queue (index, 0);
5587 do_pending_stack_adjust ();
5589 op_mode = insn_data[(int) CODE_FOR_casesi].operand[0].mode;
5590 if (! (*insn_data[(int) CODE_FOR_casesi].operand[0].predicate)
5592 index = copy_to_mode_reg (op_mode, index);
5594 op1 = expand_expr (minval, NULL_RTX, VOIDmode, 0);
5596 op_mode = insn_data[(int) CODE_FOR_casesi].operand[1].mode;
5597 if (! (*insn_data[(int) CODE_FOR_casesi].operand[1].predicate)
5599 op1 = copy_to_mode_reg (op_mode, op1);
5601 op2 = expand_expr (range, NULL_RTX, VOIDmode, 0);
5603 op_mode = insn_data[(int) CODE_FOR_casesi].operand[2].mode;
5604 if (! (*insn_data[(int) CODE_FOR_casesi].operand[2].predicate)
5606 op2 = copy_to_mode_reg (op_mode, op2);
5608 emit_jump_insn (gen_casesi (index, op1, op2,
5609 table_label, default_label));
5613 #ifdef HAVE_tablejump
5614 if (! win && HAVE_tablejump)
5616 index_type = thiscase->data.case_stmt.nominal_type;
5617 index_expr = fold (build (MINUS_EXPR, index_type,
5618 convert (index_type, index_expr),
5619 convert (index_type, minval)));
5620 index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
5622 index = protect_from_queue (index, 0);
5623 do_pending_stack_adjust ();
5625 do_tablejump (index, TYPE_MODE (index_type),
5626 expand_expr (range, NULL_RTX, VOIDmode, 0),
5627 table_label, default_label);
5634 /* Get table of labels to jump to, in order of case index. */
5636 ncases = TREE_INT_CST_LOW (range) + 1;
5637 labelvec = (rtx *) alloca (ncases * sizeof (rtx));
5638 memset ((char *) labelvec, 0, ncases * sizeof (rtx));
5640 for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
5642 register HOST_WIDE_INT i
5643 = TREE_INT_CST_LOW (n->low) - TREE_INT_CST_LOW (orig_minval);
5648 = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
5649 if (i + TREE_INT_CST_LOW (orig_minval)
5650 == TREE_INT_CST_LOW (n->high))
5656 /* Fill in the gaps with the default. */
5657 for (i = 0; i < ncases; i++)
5658 if (labelvec[i] == 0)
5659 labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
5661 /* Output the table */
5662 emit_label (table_label);
5664 if (CASE_VECTOR_PC_RELATIVE || flag_pic)
5665 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
5666 gen_rtx_LABEL_REF (Pmode, table_label),
5667 gen_rtvec_v (ncases, labelvec),
5668 const0_rtx, const0_rtx));
5670 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
5671 gen_rtvec_v (ncases, labelvec)));
5673 /* If the case insn drops through the table,
5674 after the table we must jump to the default-label.
5675 Otherwise record no drop-through after the table. */
5676 #ifdef CASE_DROPS_THROUGH
5677 emit_jump (default_label);
5683 before_case = squeeze_notes (NEXT_INSN (before_case), get_last_insn ());
5684 reorder_insns (before_case, get_last_insn (),
5685 thiscase->data.case_stmt.start);
5688 end_cleanup_deferral ();
5690 if (thiscase->exit_label)
5691 emit_label (thiscase->exit_label);
5693 free_case_nodes (case_stack->data.case_stmt.case_list);
5694 POPSTACK (case_stack);
5699 /* Convert the tree NODE into a list linked by the right field, with the left
5700 field zeroed. RIGHT is used for recursion; it is a list to be placed
5701 rightmost in the resulting list. */
5703 static struct case_node *
5704 case_tree2list (node, right)
5705 struct case_node *node, *right;
5707 struct case_node *left;
5710 right = case_tree2list (node->right, right);
5712 node->right = right;
5713 if ((left = node->left))
5716 return case_tree2list (left, node);
5722 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5725 do_jump_if_equal (op1, op2, label, unsignedp)
5726 rtx op1, op2, label;
5729 if (GET_CODE (op1) == CONST_INT
5730 && GET_CODE (op2) == CONST_INT)
5732 if (INTVAL (op1) == INTVAL (op2))
5737 enum machine_mode mode = GET_MODE (op1);
5738 if (mode == VOIDmode)
5739 mode = GET_MODE (op2);
5740 emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX, mode, unsignedp,
5745 /* Not all case values are encountered equally. This function
5746 uses a heuristic to weight case labels, in cases where that
5747 looks like a reasonable thing to do.
5749 Right now, all we try to guess is text, and we establish the
5752 chars above space: 16
5761 If we find any cases in the switch that are not either -1 or in the range
5762 of valid ASCII characters, or are control characters other than those
5763 commonly used with "\", don't treat this switch scanning text.
5765 Return 1 if these nodes are suitable for cost estimation, otherwise
5769 estimate_case_costs (node)
5772 tree min_ascii = integer_minus_one_node;
5773 tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
5777 /* If we haven't already made the cost table, make it now. Note that the
5778 lower bound of the table is -1, not zero. */
5780 if (! cost_table_initialized)
5782 cost_table_initialized = 1;
5784 for (i = 0; i < 128; i++)
5787 COST_TABLE (i) = 16;
5788 else if (ISPUNCT (i))
5790 else if (ISCNTRL (i))
5791 COST_TABLE (i) = -1;
5794 COST_TABLE (' ') = 8;
5795 COST_TABLE ('\t') = 4;
5796 COST_TABLE ('\0') = 4;
5797 COST_TABLE ('\n') = 2;
5798 COST_TABLE ('\f') = 1;
5799 COST_TABLE ('\v') = 1;
5800 COST_TABLE ('\b') = 1;
5803 /* See if all the case expressions look like text. It is text if the
5804 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5805 as signed arithmetic since we don't want to ever access cost_table with a
5806 value less than -1. Also check that none of the constants in a range
5807 are strange control characters. */
5809 for (n = node; n; n = n->right)
5811 if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
5814 for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
5815 i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
5816 if (COST_TABLE (i) < 0)
5820 /* All interesting values are within the range of interesting
5821 ASCII characters. */
5825 /* Scan an ordered list of case nodes
5826 combining those with consecutive values or ranges.
5828 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5831 group_case_nodes (head)
5834 case_node_ptr node = head;
5838 rtx lb = next_real_insn (label_rtx (node->code_label));
5840 case_node_ptr np = node;
5842 /* Try to group the successors of NODE with NODE. */
5843 while (((np = np->right) != 0)
5844 /* Do they jump to the same place? */
5845 && ((lb2 = next_real_insn (label_rtx (np->code_label))) == lb
5846 || (lb != 0 && lb2 != 0
5847 && simplejump_p (lb)
5848 && simplejump_p (lb2)
5849 && rtx_equal_p (SET_SRC (PATTERN (lb)),
5850 SET_SRC (PATTERN (lb2)))))
5851 /* Are their ranges consecutive? */
5852 && tree_int_cst_equal (np->low,
5853 fold (build (PLUS_EXPR,
5854 TREE_TYPE (node->high),
5857 /* An overflow is not consecutive. */
5858 && tree_int_cst_lt (node->high,
5859 fold (build (PLUS_EXPR,
5860 TREE_TYPE (node->high),
5862 integer_one_node))))
5864 node->high = np->high;
5866 /* NP is the first node after NODE which can't be grouped with it.
5867 Delete the nodes in between, and move on to that node. */
5873 /* Take an ordered list of case nodes
5874 and transform them into a near optimal binary tree,
5875 on the assumption that any target code selection value is as
5876 likely as any other.
5878 The transformation is performed by splitting the ordered
5879 list into two equal sections plus a pivot. The parts are
5880 then attached to the pivot as left and right branches. Each
5881 branch is then transformed recursively. */
5884 balance_case_nodes (head, parent)
5885 case_node_ptr *head;
5886 case_node_ptr parent;
5888 register case_node_ptr np;
5896 register case_node_ptr *npp;
5899 /* Count the number of entries on branch. Also count the ranges. */
5903 if (!tree_int_cst_equal (np->low, np->high))
5907 cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
5911 cost += COST_TABLE (TREE_INT_CST_LOW (np->low));
5919 /* Split this list if it is long enough for that to help. */
5924 /* Find the place in the list that bisects the list's total cost,
5925 Here I gets half the total cost. */
5930 /* Skip nodes while their cost does not reach that amount. */
5931 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5932 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
5933 i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
5936 npp = &(*npp)->right;
5941 /* Leave this branch lopsided, but optimize left-hand
5942 side and fill in `parent' fields for right-hand side. */
5944 np->parent = parent;
5945 balance_case_nodes (&np->left, np);
5946 for (; np->right; np = np->right)
5947 np->right->parent = np;
5951 /* If there are just three nodes, split at the middle one. */
5953 npp = &(*npp)->right;
5956 /* Find the place in the list that bisects the list's total cost,
5957 where ranges count as 2.
5958 Here I gets half the total cost. */
5959 i = (i + ranges + 1) / 2;
5962 /* Skip nodes while their cost does not reach that amount. */
5963 if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
5968 npp = &(*npp)->right;
5973 np->parent = parent;
5976 /* Optimize each of the two split parts. */
5977 balance_case_nodes (&np->left, np);
5978 balance_case_nodes (&np->right, np);
5982 /* Else leave this branch as one level,
5983 but fill in `parent' fields. */
5985 np->parent = parent;
5986 for (; np->right; np = np->right)
5987 np->right->parent = np;
5992 /* Search the parent sections of the case node tree
5993 to see if a test for the lower bound of NODE would be redundant.
5994 INDEX_TYPE is the type of the index expression.
5996 The instructions to generate the case decision tree are
5997 output in the same order as nodes are processed so it is
5998 known that if a parent node checks the range of the current
5999 node minus one that the current node is bounded at its lower
6000 span. Thus the test would be redundant. */
6003 node_has_low_bound (node, index_type)
6008 case_node_ptr pnode;
6010 /* If the lower bound of this node is the lowest value in the index type,
6011 we need not test it. */
6013 if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
6016 /* If this node has a left branch, the value at the left must be less
6017 than that at this node, so it cannot be bounded at the bottom and
6018 we need not bother testing any further. */
6023 low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
6024 node->low, integer_one_node));
6026 /* If the subtraction above overflowed, we can't verify anything.
6027 Otherwise, look for a parent that tests our value - 1. */
6029 if (! tree_int_cst_lt (low_minus_one, node->low))
6032 for (pnode = node->parent; pnode; pnode = pnode->parent)
6033 if (tree_int_cst_equal (low_minus_one, pnode->high))
6039 /* Search the parent sections of the case node tree
6040 to see if a test for the upper bound of NODE would be redundant.
6041 INDEX_TYPE is the type of the index expression.
6043 The instructions to generate the case decision tree are
6044 output in the same order as nodes are processed so it is
6045 known that if a parent node checks the range of the current
6046 node plus one that the current node is bounded at its upper
6047 span. Thus the test would be redundant. */
6050 node_has_high_bound (node, index_type)
6055 case_node_ptr pnode;
6057 /* If there is no upper bound, obviously no test is needed. */
6059 if (TYPE_MAX_VALUE (index_type) == NULL)
6062 /* If the upper bound of this node is the highest value in the type
6063 of the index expression, we need not test against it. */
6065 if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
6068 /* If this node has a right branch, the value at the right must be greater
6069 than that at this node, so it cannot be bounded at the top and
6070 we need not bother testing any further. */
6075 high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
6076 node->high, integer_one_node));
6078 /* If the addition above overflowed, we can't verify anything.
6079 Otherwise, look for a parent that tests our value + 1. */
6081 if (! tree_int_cst_lt (node->high, high_plus_one))
6084 for (pnode = node->parent; pnode; pnode = pnode->parent)
6085 if (tree_int_cst_equal (high_plus_one, pnode->low))
6091 /* Search the parent sections of the
6092 case node tree to see if both tests for the upper and lower
6093 bounds of NODE would be redundant. */
6096 node_is_bounded (node, index_type)
6100 return (node_has_low_bound (node, index_type)
6101 && node_has_high_bound (node, index_type));
6104 /* Emit an unconditional jump to LABEL unless it would be dead code. */
6107 emit_jump_if_reachable (label)
6110 if (GET_CODE (get_last_insn ()) != BARRIER)
6114 /* Emit step-by-step code to select a case for the value of INDEX.
6115 The thus generated decision tree follows the form of the
6116 case-node binary tree NODE, whose nodes represent test conditions.
6117 INDEX_TYPE is the type of the index of the switch.
6119 Care is taken to prune redundant tests from the decision tree
6120 by detecting any boundary conditions already checked by
6121 emitted rtx. (See node_has_high_bound, node_has_low_bound
6122 and node_is_bounded, above.)
6124 Where the test conditions can be shown to be redundant we emit
6125 an unconditional jump to the target code. As a further
6126 optimization, the subordinates of a tree node are examined to
6127 check for bounded nodes. In this case conditional and/or
6128 unconditional jumps as a result of the boundary check for the
6129 current node are arranged to target the subordinates associated
6130 code for out of bound conditions on the current node.
6132 We can assume that when control reaches the code generated here,
6133 the index value has already been compared with the parents
6134 of this node, and determined to be on the same side of each parent
6135 as this node is. Thus, if this node tests for the value 51,
6136 and a parent tested for 52, we don't need to consider
6137 the possibility of a value greater than 51. If another parent
6138 tests for the value 50, then this node need not test anything. */
6141 emit_case_nodes (index, node, default_label, index_type)
6147 /* If INDEX has an unsigned type, we must make unsigned branches. */
6148 int unsignedp = TREE_UNSIGNED (index_type);
6149 enum machine_mode mode = GET_MODE (index);
6151 /* See if our parents have already tested everything for us.
6152 If they have, emit an unconditional jump for this node. */
6153 if (node_is_bounded (node, index_type))
6154 emit_jump (label_rtx (node->code_label));
6156 else if (tree_int_cst_equal (node->low, node->high))
6158 /* Node is single valued. First see if the index expression matches
6159 this node and then check our children, if any. */
6161 do_jump_if_equal (index, expand_expr (node->low, NULL_RTX, VOIDmode, 0),
6162 label_rtx (node->code_label), unsignedp);
6164 if (node->right != 0 && node->left != 0)
6166 /* This node has children on both sides.
6167 Dispatch to one side or the other
6168 by comparing the index value with this node's value.
6169 If one subtree is bounded, check that one first,
6170 so we can avoid real branches in the tree. */
6172 if (node_is_bounded (node->right, index_type))
6174 emit_cmp_and_jump_insns (index,
6175 expand_expr (node->high, NULL_RTX,
6177 GT, NULL_RTX, mode, unsignedp, 0,
6178 label_rtx (node->right->code_label));
6179 emit_case_nodes (index, node->left, default_label, index_type);
6182 else if (node_is_bounded (node->left, index_type))
6184 emit_cmp_and_jump_insns (index,
6185 expand_expr (node->high, NULL_RTX,
6187 LT, NULL_RTX, mode, unsignedp, 0,
6188 label_rtx (node->left->code_label));
6189 emit_case_nodes (index, node->right, default_label, index_type);
6194 /* Neither node is bounded. First distinguish the two sides;
6195 then emit the code for one side at a time. */
6197 tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6199 /* See if the value is on the right. */
6200 emit_cmp_and_jump_insns (index,
6201 expand_expr (node->high, NULL_RTX,
6203 GT, NULL_RTX, mode, unsignedp, 0,
6204 label_rtx (test_label));
6206 /* Value must be on the left.
6207 Handle the left-hand subtree. */
6208 emit_case_nodes (index, node->left, default_label, index_type);
6209 /* If left-hand subtree does nothing,
6211 emit_jump_if_reachable (default_label);
6213 /* Code branches here for the right-hand subtree. */
6214 expand_label (test_label);
6215 emit_case_nodes (index, node->right, default_label, index_type);
6219 else if (node->right != 0 && node->left == 0)
6221 /* Here we have a right child but no left so we issue conditional
6222 branch to default and process the right child.
6224 Omit the conditional branch to default if we it avoid only one
6225 right child; it costs too much space to save so little time. */
6227 if (node->right->right || node->right->left
6228 || !tree_int_cst_equal (node->right->low, node->right->high))
6230 if (!node_has_low_bound (node, index_type))
6232 emit_cmp_and_jump_insns (index,
6233 expand_expr (node->high, NULL_RTX,
6235 LT, NULL_RTX, mode, unsignedp, 0,
6239 emit_case_nodes (index, node->right, default_label, index_type);
6242 /* We cannot process node->right normally
6243 since we haven't ruled out the numbers less than
6244 this node's value. So handle node->right explicitly. */
6245 do_jump_if_equal (index,
6246 expand_expr (node->right->low, NULL_RTX,
6248 label_rtx (node->right->code_label), unsignedp);
6251 else if (node->right == 0 && node->left != 0)
6253 /* Just one subtree, on the left. */
6255 #if 0 /* The following code and comment were formerly part
6256 of the condition here, but they didn't work
6257 and I don't understand what the idea was. -- rms. */
6258 /* If our "most probable entry" is less probable
6259 than the default label, emit a jump to
6260 the default label using condition codes
6261 already lying around. With no right branch,
6262 a branch-greater-than will get us to the default
6265 && COST_TABLE (TREE_INT_CST_LOW (node->high)) < 12)
6268 if (node->left->left || node->left->right
6269 || !tree_int_cst_equal (node->left->low, node->left->high))
6271 if (!node_has_high_bound (node, index_type))
6273 emit_cmp_and_jump_insns (index, expand_expr (node->high,
6276 GT, NULL_RTX, mode, unsignedp, 0,
6280 emit_case_nodes (index, node->left, default_label, index_type);
6283 /* We cannot process node->left normally
6284 since we haven't ruled out the numbers less than
6285 this node's value. So handle node->left explicitly. */
6286 do_jump_if_equal (index,
6287 expand_expr (node->left->low, NULL_RTX,
6289 label_rtx (node->left->code_label), unsignedp);
6294 /* Node is a range. These cases are very similar to those for a single
6295 value, except that we do not start by testing whether this node
6296 is the one to branch to. */
6298 if (node->right != 0 && node->left != 0)
6300 /* Node has subtrees on both sides.
6301 If the right-hand subtree is bounded,
6302 test for it first, since we can go straight there.
6303 Otherwise, we need to make a branch in the control structure,
6304 then handle the two subtrees. */
6305 tree test_label = 0;
6307 if (node_is_bounded (node->right, index_type))
6308 /* Right hand node is fully bounded so we can eliminate any
6309 testing and branch directly to the target code. */
6310 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6312 GT, NULL_RTX, mode, unsignedp, 0,
6313 label_rtx (node->right->code_label));
6316 /* Right hand node requires testing.
6317 Branch to a label where we will handle it later. */
6319 test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
6320 emit_cmp_and_jump_insns (index,
6321 expand_expr (node->high, NULL_RTX,
6323 GT, NULL_RTX, mode, unsignedp, 0,
6324 label_rtx (test_label));
6327 /* Value belongs to this node or to the left-hand subtree. */
6329 emit_cmp_and_jump_insns (index, expand_expr (node->low, NULL_RTX,
6331 GE, NULL_RTX, mode, unsignedp, 0,
6332 label_rtx (node->code_label));
6334 /* Handle the left-hand subtree. */
6335 emit_case_nodes (index, node->left, default_label, index_type);
6337 /* If right node had to be handled later, do that now. */
6341 /* If the left-hand subtree fell through,
6342 don't let it fall into the right-hand subtree. */
6343 emit_jump_if_reachable (default_label);
6345 expand_label (test_label);
6346 emit_case_nodes (index, node->right, default_label, index_type);
6350 else if (node->right != 0 && node->left == 0)
6352 /* Deal with values to the left of this node,
6353 if they are possible. */
6354 if (!node_has_low_bound (node, index_type))
6356 emit_cmp_and_jump_insns (index,
6357 expand_expr (node->low, NULL_RTX,
6359 LT, NULL_RTX, mode, unsignedp, 0,
6363 /* Value belongs to this node or to the right-hand subtree. */
6365 emit_cmp_and_jump_insns (index, expand_expr (node->high, NULL_RTX,
6367 LE, NULL_RTX, mode, unsignedp, 0,
6368 label_rtx (node->code_label));
6370 emit_case_nodes (index, node->right, default_label, index_type);
6373 else if (node->right == 0 && node->left != 0)
6375 /* Deal with values to the right of this node,
6376 if they are possible. */
6377 if (!node_has_high_bound (node, index_type))
6379 emit_cmp_and_jump_insns (index,
6380 expand_expr (node->high, NULL_RTX,
6382 GT, NULL_RTX, mode, unsignedp, 0,
6386 /* Value belongs to this node or to the left-hand subtree. */
6388 emit_cmp_and_jump_insns (index,
6389 expand_expr (node->low, NULL_RTX,
6391 GE, NULL_RTX, mode, unsignedp, 0,
6392 label_rtx (node->code_label));
6394 emit_case_nodes (index, node->left, default_label, index_type);
6399 /* Node has no children so we check low and high bounds to remove
6400 redundant tests. Only one of the bounds can exist,
6401 since otherwise this node is bounded--a case tested already. */
6403 if (!node_has_high_bound (node, index_type))
6405 emit_cmp_and_jump_insns (index,
6406 expand_expr (node->high, NULL_RTX,
6408 GT, NULL_RTX, mode, unsignedp, 0,
6412 if (!node_has_low_bound (node, index_type))
6414 emit_cmp_and_jump_insns (index,
6415 expand_expr (node->low, NULL_RTX,
6417 LT, NULL_RTX, mode, unsignedp, 0,
6421 emit_jump (label_rtx (node->code_label));