1 /* GIMPLE lowering pass. Converts High GIMPLE into Low GIMPLE.
3 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
29 #include "tree-iterator.h"
30 #include "tree-inline.h"
31 #include "diagnostic.h"
32 #include "langhooks.h"
33 #include "langhooks-def.h"
34 #include "tree-flow.h"
42 #include "tree-pass.h"
44 /* The differences between High GIMPLE and Low GIMPLE are the
47 1- Lexical scopes are removed (i.e., GIMPLE_BIND disappears).
49 2- GIMPLE_TRY and GIMPLE_CATCH are converted to abnormal control
50 flow and exception regions are built as an on-the-side region
51 hierarchy (See tree-eh.c:lower_eh_constructs).
53 3- Multiple identical return statements are grouped into a single
54 return and gotos to the unique return site. */
56 /* Match a return statement with a label. During lowering, we identify
57 identical return statements and replace duplicates with a jump to
58 the corresponding label. */
59 struct return_statements_t
64 typedef struct return_statements_t return_statements_t;
66 DEF_VEC_O(return_statements_t);
67 DEF_VEC_ALLOC_O(return_statements_t,heap);
71 /* Block the current statement belongs to. */
74 /* A vector of label and return statements to be moved to the end
76 VEC(return_statements_t,heap) *return_statements;
78 /* True if the function calls __builtin_setjmp. */
79 bool calls_builtin_setjmp;
82 static void lower_stmt (gimple_stmt_iterator *, struct lower_data *);
83 static void lower_gimple_bind (gimple_stmt_iterator *, struct lower_data *);
84 static void lower_gimple_return (gimple_stmt_iterator *, struct lower_data *);
85 static void lower_builtin_setjmp (gimple_stmt_iterator *);
88 /* Lower the body of current_function_decl from High GIMPLE into Low
92 lower_function_body (void)
94 struct lower_data data;
95 gimple_seq body = gimple_body (current_function_decl);
96 gimple_seq lowered_body;
97 gimple_stmt_iterator i;
102 /* The gimplifier should've left a body of exactly one statement,
103 namely a GIMPLE_BIND. */
104 gcc_assert (gimple_seq_first (body) == gimple_seq_last (body)
105 && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND);
107 memset (&data, 0, sizeof (data));
108 data.block = DECL_INITIAL (current_function_decl);
109 BLOCK_SUBBLOCKS (data.block) = NULL_TREE;
110 BLOCK_CHAIN (data.block) = NULL_TREE;
111 TREE_ASM_WRITTEN (data.block) = 1;
112 data.return_statements = VEC_alloc (return_statements_t, heap, 8);
114 bind = gimple_seq_first_stmt (body);
116 gimple_seq_add_stmt (&lowered_body, bind);
117 i = gsi_start (lowered_body);
118 lower_gimple_bind (&i, &data);
120 /* Once the old body has been lowered, replace it with the new
122 gimple_set_body (current_function_decl, lowered_body);
124 i = gsi_last (lowered_body);
126 /* If the function falls off the end, we need a null return statement.
127 If we've already got one in the return_statements vector, we don't
128 need to do anything special. Otherwise build one by hand. */
129 if (gimple_seq_may_fallthru (lowered_body)
130 && (VEC_empty (return_statements_t, data.return_statements)
131 || gimple_return_retval (VEC_last (return_statements_t,
132 data.return_statements)->stmt) != NULL))
134 x = gimple_build_return (NULL);
135 gimple_set_location (x, cfun->function_end_locus);
136 gimple_set_block (x, DECL_INITIAL (current_function_decl));
137 gsi_insert_after (&i, x, GSI_CONTINUE_LINKING);
140 /* If we lowered any return statements, emit the representative
141 at the end of the function. */
142 while (!VEC_empty (return_statements_t, data.return_statements))
144 return_statements_t t;
146 /* Unfortunately, we can't use VEC_pop because it returns void for
148 t = *VEC_last (return_statements_t, data.return_statements);
149 VEC_truncate (return_statements_t,
150 data.return_statements,
151 VEC_length (return_statements_t,
152 data.return_statements) - 1);
154 x = gimple_build_label (t.label);
155 gsi_insert_after (&i, x, GSI_CONTINUE_LINKING);
157 /* Remove the line number from the representative return statement.
158 It now fills in for many such returns. Failure to remove this
159 will result in incorrect results for coverage analysis. */
160 gimple_set_location (t.stmt, UNKNOWN_LOCATION);
161 gsi_insert_after (&i, t.stmt, GSI_CONTINUE_LINKING);
164 /* If the function calls __builtin_setjmp, we need to emit the computed
165 goto that will serve as the unique dispatcher for all the receivers. */
166 if (data.calls_builtin_setjmp)
168 tree disp_label, disp_var, arg;
170 /* Build 'DISP_LABEL:' and insert. */
171 disp_label = create_artificial_label ();
172 /* This mark will create forward edges from every call site. */
173 DECL_NONLOCAL (disp_label) = 1;
174 cfun->has_nonlocal_label = 1;
175 x = gimple_build_label (disp_label);
176 gsi_insert_after (&i, x, GSI_CONTINUE_LINKING);
178 /* Build 'DISP_VAR = __builtin_setjmp_dispatcher (DISP_LABEL);'
180 disp_var = create_tmp_var (ptr_type_node, "setjmpvar");
181 arg = build_addr (disp_label, current_function_decl);
182 t = implicit_built_in_decls[BUILT_IN_SETJMP_DISPATCHER];
183 x = gimple_build_call (t, 1, arg);
184 gimple_call_set_lhs (x, disp_var);
186 /* Build 'goto DISP_VAR;' and insert. */
187 gsi_insert_after (&i, x, GSI_CONTINUE_LINKING);
188 x = gimple_build_goto (disp_var);
189 gsi_insert_after (&i, x, GSI_CONTINUE_LINKING);
192 gcc_assert (data.block == DECL_INITIAL (current_function_decl));
193 BLOCK_SUBBLOCKS (data.block)
194 = blocks_nreverse (BLOCK_SUBBLOCKS (data.block));
196 clear_block_marks (data.block);
197 VEC_free(return_statements_t, heap, data.return_statements);
201 struct gimple_opt_pass pass_lower_cf =
207 lower_function_body, /* execute */
210 0, /* static_pass_number */
212 PROP_gimple_any, /* properties_required */
213 PROP_gimple_lcf, /* properties_provided */
214 0, /* properties_destroyed */
215 0, /* todo_flags_start */
216 TODO_dump_func /* todo_flags_finish */
221 /* Lower sequence SEQ. Unlike gimplification the statements are not relowered
222 when they are changed -- if this has to be done, the lowering routine must
223 do it explicitly. DATA is passed through the recursion. */
226 lower_sequence (gimple_seq seq, struct lower_data *data)
228 gimple_stmt_iterator gsi;
230 for (gsi = gsi_start (seq); !gsi_end_p (gsi); )
231 lower_stmt (&gsi, data);
235 /* Lower the OpenMP directive statement pointed by GSI. DATA is
236 passed through the recursion. */
239 lower_omp_directive (gimple_stmt_iterator *gsi, struct lower_data *data)
243 stmt = gsi_stmt (*gsi);
245 lower_sequence (gimple_omp_body (stmt), data);
246 gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
247 gsi_insert_seq_before (gsi, gimple_omp_body (stmt), GSI_SAME_STMT);
248 gimple_omp_set_body (stmt, NULL);
249 gsi_remove (gsi, false);
253 /* Lower statement GSI. DATA is passed through the recursion. */
256 lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data)
258 gimple stmt = gsi_stmt (*gsi);
260 gimple_set_block (stmt, data->block);
262 switch (gimple_code (stmt))
265 lower_gimple_bind (gsi, data);
269 /* The gimplifier has already lowered this into gotos. */
273 lower_gimple_return (gsi, data);
277 lower_sequence (gimple_try_eval (stmt), data);
278 lower_sequence (gimple_try_cleanup (stmt), data);
282 lower_sequence (gimple_catch_handler (stmt), data);
285 case GIMPLE_EH_FILTER:
286 lower_sequence (gimple_eh_filter_failure (stmt), data);
296 case GIMPLE_CHANGE_DYNAMIC_TYPE:
298 case GIMPLE_OMP_SECTIONS:
299 case GIMPLE_OMP_SECTIONS_SWITCH:
300 case GIMPLE_OMP_SECTION:
301 case GIMPLE_OMP_SINGLE:
302 case GIMPLE_OMP_MASTER:
303 case GIMPLE_OMP_ORDERED:
304 case GIMPLE_OMP_CRITICAL:
305 case GIMPLE_OMP_RETURN:
306 case GIMPLE_OMP_ATOMIC_LOAD:
307 case GIMPLE_OMP_ATOMIC_STORE:
308 case GIMPLE_OMP_CONTINUE:
313 tree decl = gimple_call_fndecl (stmt);
316 && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
317 && DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP)
319 data->calls_builtin_setjmp = true;
320 lower_builtin_setjmp (gsi);
326 case GIMPLE_OMP_PARALLEL:
327 case GIMPLE_OMP_TASK:
328 lower_omp_directive (gsi, data);
338 /* Lower a bind_expr TSI. DATA is passed through the recursion. */
341 lower_gimple_bind (gimple_stmt_iterator *gsi, struct lower_data *data)
343 tree old_block = data->block;
344 gimple stmt = gsi_stmt (*gsi);
345 tree new_block = gimple_bind_block (stmt);
349 if (new_block == old_block)
351 /* The outermost block of the original function may not be the
352 outermost statement chain of the gimplified function. So we
353 may see the outermost block just inside the function. */
354 gcc_assert (new_block == DECL_INITIAL (current_function_decl));
359 /* We do not expect to handle duplicate blocks. */
360 gcc_assert (!TREE_ASM_WRITTEN (new_block));
361 TREE_ASM_WRITTEN (new_block) = 1;
363 /* Block tree may get clobbered by inlining. Normally this would
364 be fixed in rest_of_decl_compilation using block notes, but
365 since we are not going to emit them, it is up to us. */
366 BLOCK_CHAIN (new_block) = BLOCK_SUBBLOCKS (old_block);
367 BLOCK_SUBBLOCKS (old_block) = new_block;
368 BLOCK_SUBBLOCKS (new_block) = NULL_TREE;
369 BLOCK_SUPERCONTEXT (new_block) = old_block;
371 data->block = new_block;
375 record_vars (gimple_bind_vars (stmt));
376 lower_sequence (gimple_bind_body (stmt), data);
380 gcc_assert (data->block == new_block);
382 BLOCK_SUBBLOCKS (new_block)
383 = blocks_nreverse (BLOCK_SUBBLOCKS (new_block));
384 data->block = old_block;
387 /* The GIMPLE_BIND no longer carries any useful information -- kill it. */
388 gsi_insert_seq_before (gsi, gimple_bind_body (stmt), GSI_SAME_STMT);
389 gsi_remove (gsi, false);
392 /* Try to determine whether a TRY_CATCH expression can fall through.
393 This is a subroutine of block_may_fallthru. */
396 try_catch_may_fallthru (const_tree stmt)
398 tree_stmt_iterator i;
400 /* If the TRY block can fall through, the whole TRY_CATCH can
402 if (block_may_fallthru (TREE_OPERAND (stmt, 0)))
405 i = tsi_start (TREE_OPERAND (stmt, 1));
406 switch (TREE_CODE (tsi_stmt (i)))
409 /* We expect to see a sequence of CATCH_EXPR trees, each with a
410 catch expression and a body. The whole TRY_CATCH may fall
411 through iff any of the catch bodies falls through. */
412 for (; !tsi_end_p (i); tsi_next (&i))
414 if (block_may_fallthru (CATCH_BODY (tsi_stmt (i))))
420 /* The exception filter expression only matters if there is an
421 exception. If the exception does not match EH_FILTER_TYPES,
422 we will execute EH_FILTER_FAILURE, and we will fall through
423 if that falls through. If the exception does match
424 EH_FILTER_TYPES, the stack unwinder will continue up the
425 stack, so we will not fall through. We don't know whether we
426 will throw an exception which matches EH_FILTER_TYPES or not,
427 so we just ignore EH_FILTER_TYPES and assume that we might
428 throw an exception which doesn't match. */
429 return block_may_fallthru (EH_FILTER_FAILURE (tsi_stmt (i)));
432 /* This case represents statements to be executed when an
433 exception occurs. Those statements are implicitly followed
434 by a RESX_EXPR to resume execution after the exception. So
435 in this case the TRY_CATCH never falls through. */
441 /* Same as above, but for a GIMPLE_TRY_CATCH. */
444 gimple_try_catch_may_fallthru (gimple stmt)
446 gimple_stmt_iterator i;
448 /* We don't handle GIMPLE_TRY_FINALLY. */
449 gcc_assert (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH);
451 /* If the TRY block can fall through, the whole TRY_CATCH can
453 if (gimple_seq_may_fallthru (gimple_try_eval (stmt)))
456 i = gsi_start (gimple_try_cleanup (stmt));
457 switch (gimple_code (gsi_stmt (i)))
460 /* We expect to see a sequence of GIMPLE_CATCH stmts, each with a
461 catch expression and a body. The whole try/catch may fall
462 through iff any of the catch bodies falls through. */
463 for (; !gsi_end_p (i); gsi_next (&i))
465 if (gimple_seq_may_fallthru (gimple_catch_handler (gsi_stmt (i))))
470 case GIMPLE_EH_FILTER:
471 /* The exception filter expression only matters if there is an
472 exception. If the exception does not match EH_FILTER_TYPES,
473 we will execute EH_FILTER_FAILURE, and we will fall through
474 if that falls through. If the exception does match
475 EH_FILTER_TYPES, the stack unwinder will continue up the
476 stack, so we will not fall through. We don't know whether we
477 will throw an exception which matches EH_FILTER_TYPES or not,
478 so we just ignore EH_FILTER_TYPES and assume that we might
479 throw an exception which doesn't match. */
480 return gimple_seq_may_fallthru (gimple_eh_filter_failure (gsi_stmt (i)));
483 /* This case represents statements to be executed when an
484 exception occurs. Those statements are implicitly followed
485 by a GIMPLE_RESX to resume execution after the exception. So
486 in this case the try/catch never falls through. */
492 /* Try to determine if we can fall out of the bottom of BLOCK. This guess
493 need not be 100% accurate; simply be conservative and return true if we
494 don't know. This is used only to avoid stupidly generating extra code.
495 If we're wrong, we'll just delete the extra code later. */
498 block_may_fallthru (const_tree block)
500 /* This CONST_CAST is okay because expr_last returns its argument
501 unmodified and we assign it to a const_tree. */
502 const_tree stmt = expr_last (CONST_CAST_TREE(block));
504 switch (stmt ? TREE_CODE (stmt) : ERROR_MARK)
509 /* Easy cases. If the last statement of the block implies
510 control transfer, then we can't fall through. */
514 /* If SWITCH_LABELS is set, this is lowered, and represents a
515 branch to a selected label and hence can not fall through.
516 Otherwise SWITCH_BODY is set, and the switch can fall
518 return SWITCH_LABELS (stmt) == NULL_TREE;
521 if (block_may_fallthru (COND_EXPR_THEN (stmt)))
523 return block_may_fallthru (COND_EXPR_ELSE (stmt));
526 return block_may_fallthru (BIND_EXPR_BODY (stmt));
529 return try_catch_may_fallthru (stmt);
531 case TRY_FINALLY_EXPR:
532 /* The finally clause is always executed after the try clause,
533 so if it does not fall through, then the try-finally will not
534 fall through. Otherwise, if the try clause does not fall
535 through, then when the finally clause falls through it will
536 resume execution wherever the try clause was going. So the
537 whole try-finally will only fall through if both the try
538 clause and the finally clause fall through. */
539 return (block_may_fallthru (TREE_OPERAND (stmt, 0))
540 && block_may_fallthru (TREE_OPERAND (stmt, 1)));
543 if (TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR)
544 stmt = TREE_OPERAND (stmt, 1);
550 /* Functions that do not return do not fall through. */
551 return (call_expr_flags (stmt) & ECF_NORETURN) == 0;
553 case CLEANUP_POINT_EXPR:
554 return block_may_fallthru (TREE_OPERAND (stmt, 0));
562 /* Try to determine if we can continue executing the statement
563 immediately following STMT. This guess need not be 100% accurate;
564 simply be conservative and return true if we don't know. This is
565 used only to avoid stupidly generating extra code. If we're wrong,
566 we'll just delete the extra code later. */
569 gimple_stmt_may_fallthru (gimple stmt)
574 switch (gimple_code (stmt))
579 /* Easy cases. If the last statement of the seq implies
580 control transfer, then we can't fall through. */
584 /* Switch has already been lowered and represents a
585 branch to a selected label and hence can not fall through. */
589 /* GIMPLE_COND's are already lowered into a two-way branch. They
590 can't fall through. */
594 return gimple_seq_may_fallthru (gimple_bind_body (stmt));
597 if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH)
598 return gimple_try_catch_may_fallthru (stmt);
600 /* It must be a GIMPLE_TRY_FINALLY. */
602 /* The finally clause is always executed after the try clause,
603 so if it does not fall through, then the try-finally will not
604 fall through. Otherwise, if the try clause does not fall
605 through, then when the finally clause falls through it will
606 resume execution wherever the try clause was going. So the
607 whole try-finally will only fall through if both the try
608 clause and the finally clause fall through. */
609 return (gimple_seq_may_fallthru (gimple_try_eval (stmt))
610 && gimple_seq_may_fallthru (gimple_try_cleanup (stmt)));
616 /* Functions that do not return do not fall through. */
617 return (gimple_call_flags (stmt) & ECF_NORETURN) == 0;
625 /* Same as gimple_stmt_may_fallthru, but for the gimple sequence SEQ. */
628 gimple_seq_may_fallthru (gimple_seq seq)
630 return gimple_stmt_may_fallthru (gimple_seq_last_stmt (seq));
634 /* Lower a GIMPLE_RETURN GSI. DATA is passed through the recursion. */
637 lower_gimple_return (gimple_stmt_iterator *gsi, struct lower_data *data)
639 gimple stmt = gsi_stmt (*gsi);
642 return_statements_t tmp_rs;
644 /* Match this up with an existing return statement that's been created. */
645 for (i = VEC_length (return_statements_t, data->return_statements) - 1;
648 tmp_rs = *VEC_index (return_statements_t, data->return_statements, i);
650 if (gimple_return_retval (stmt) == gimple_return_retval (tmp_rs.stmt))
654 /* Not found. Create a new label and record the return statement. */
655 tmp_rs.label = create_artificial_label ();
657 VEC_safe_push (return_statements_t, heap, data->return_statements, &tmp_rs);
659 /* Generate a goto statement and remove the return statement. */
661 t = gimple_build_goto (tmp_rs.label);
662 gimple_set_location (t, gimple_location (stmt));
663 gimple_set_block (t, gimple_block (stmt));
664 gsi_insert_before (gsi, t, GSI_SAME_STMT);
665 gsi_remove (gsi, false);
668 /* Lower a __builtin_setjmp TSI.
670 __builtin_setjmp is passed a pointer to an array of five words (not
671 all will be used on all machines). It operates similarly to the C
672 library function of the same name, but is more efficient.
674 It is lowered into 3 other builtins, namely __builtin_setjmp_setup,
675 __builtin_setjmp_dispatcher and __builtin_setjmp_receiver, but with
676 __builtin_setjmp_dispatcher shared among all the instances; that's
677 why it is only emitted at the end by lower_function_body.
679 After full lowering, the body of the function should look like:
688 __builtin_setjmp_setup (&buf, &<D1847>);
692 __builtin_setjmp_receiver (&<D1847>);
695 if (D.1844 == 0) goto <D1848>; else goto <D1849>;
699 __builtin_setjmp_setup (&buf, &<D2847>);
703 __builtin_setjmp_receiver (&<D2847>);
706 if (D.2844 == 0) goto <D2848>; else goto <D2849>;
712 <D3853>: [non-local];
713 setjmpvar.0 = __builtin_setjmp_dispatcher (&<D3853>);
717 The dispatcher block will be both the unique destination of all the
718 abnormal call edges and the unique source of all the abnormal edges
719 to the receivers, thus keeping the complexity explosion localized. */
722 lower_builtin_setjmp (gimple_stmt_iterator *gsi)
724 gimple stmt = gsi_stmt (*gsi);
725 tree cont_label = create_artificial_label ();
726 tree next_label = create_artificial_label ();
730 /* NEXT_LABEL is the label __builtin_longjmp will jump to. Its address is
731 passed to both __builtin_setjmp_setup and __builtin_setjmp_receiver. */
732 FORCED_LABEL (next_label) = 1;
734 dest = gimple_call_lhs (stmt);
736 /* Build '__builtin_setjmp_setup (BUF, NEXT_LABEL)' and insert. */
737 arg = build_addr (next_label, current_function_decl);
738 t = implicit_built_in_decls[BUILT_IN_SETJMP_SETUP];
739 g = gimple_build_call (t, 2, gimple_call_arg (stmt, 0), arg);
740 gimple_set_location (g, gimple_location (stmt));
741 gimple_set_block (g, gimple_block (stmt));
742 gsi_insert_before (gsi, g, GSI_SAME_STMT);
744 /* Build 'DEST = 0' and insert. */
747 g = gimple_build_assign (dest, fold_convert (TREE_TYPE (dest),
749 gimple_set_location (g, gimple_location (stmt));
750 gimple_set_block (g, gimple_block (stmt));
751 gsi_insert_before (gsi, g, GSI_SAME_STMT);
754 /* Build 'goto CONT_LABEL' and insert. */
755 g = gimple_build_goto (cont_label);
756 gsi_insert_before (gsi, g, TSI_SAME_STMT);
758 /* Build 'NEXT_LABEL:' and insert. */
759 g = gimple_build_label (next_label);
760 gsi_insert_before (gsi, g, GSI_SAME_STMT);
762 /* Build '__builtin_setjmp_receiver (NEXT_LABEL)' and insert. */
763 arg = build_addr (next_label, current_function_decl);
764 t = implicit_built_in_decls[BUILT_IN_SETJMP_RECEIVER];
765 g = gimple_build_call (t, 1, arg);
766 gimple_set_location (g, gimple_location (stmt));
767 gimple_set_block (g, gimple_block (stmt));
768 gsi_insert_before (gsi, g, GSI_SAME_STMT);
770 /* Build 'DEST = 1' and insert. */
773 g = gimple_build_assign (dest, fold_convert (TREE_TYPE (dest),
775 gimple_set_location (g, gimple_location (stmt));
776 gimple_set_block (g, gimple_block (stmt));
777 gsi_insert_before (gsi, g, GSI_SAME_STMT);
780 /* Build 'CONT_LABEL:' and insert. */
781 g = gimple_build_label (cont_label);
782 gsi_insert_before (gsi, g, GSI_SAME_STMT);
784 /* Remove the call to __builtin_setjmp. */
785 gsi_remove (gsi, false);
789 /* Record the variables in VARS into function FN. */
792 record_vars_into (tree vars, tree fn)
794 if (fn != current_function_decl)
795 push_cfun (DECL_STRUCT_FUNCTION (fn));
797 for (; vars; vars = TREE_CHAIN (vars))
801 /* BIND_EXPRs contains also function/type/constant declarations
802 we don't need to care about. */
803 if (TREE_CODE (var) != VAR_DECL)
806 /* Nothing to do in this case. */
807 if (DECL_EXTERNAL (var))
810 /* Record the variable. */
811 cfun->local_decls = tree_cons (NULL_TREE, var,
815 if (fn != current_function_decl)
820 /* Record the variables in VARS into current_function_decl. */
823 record_vars (tree vars)
825 record_vars_into (vars, current_function_decl);
829 /* Mark BLOCK used if it has a used variable in it, then recurse over its
833 mark_blocks_with_used_vars (tree block)
838 if (!TREE_USED (block))
840 for (var = BLOCK_VARS (block);
842 var = TREE_CHAIN (var))
846 TREE_USED (block) = true;
851 for (subblock = BLOCK_SUBBLOCKS (block);
853 subblock = BLOCK_CHAIN (subblock))
854 mark_blocks_with_used_vars (subblock);
857 /* Mark the used attribute on blocks correctly. */
860 mark_used_blocks (void)
862 mark_blocks_with_used_vars (DECL_INITIAL (current_function_decl));
867 struct gimple_opt_pass pass_mark_used_blocks =
873 mark_used_blocks, /* execute */
876 0, /* static_pass_number */
878 0, /* properties_required */
879 0, /* properties_provided */
880 0, /* properties_destroyed */
881 0, /* todo_flags_start */
882 TODO_dump_func /* todo_flags_finish */