re PR rtl-optimization/85167 (shrink-wrap.c:333:15: runtime error with UBSAN)

	PR rtl-optimization/85167
	* shrink-wrap.c (move_insn_for_shrink_wrap): Don't set bb_uses and
	bb_defs if *split_p, instead preinitialize it to NULL.

	* gcc.dg/pr85167.c: New test.

From-SVN: r259058

gcc/ChangeLog

 2018-04-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/85167
+	* shrink-wrap.c (move_insn_for_shrink_wrap): Don't set bb_uses and
+	bb_defs if *split_p, instead preinitialize it to NULL.
+
 	PR tree-optimization/85156
 	* builtins.c (fold_builtin_expect): Use save_expr on arg1 to avoid
 	evaluating the argument multiple times.

gcc/shrink-wrap.c

@@ -157,7 +157,7 @@ move_insn_for_shrink_wrap (basic_block bb, rtx_insn *insn,
 			   struct dead_debug_local *debug)
 {
   rtx set, src, dest;
-  bitmap live_out, live_in, bb_uses, bb_defs;
+  bitmap live_out, live_in, bb_uses = NULL, bb_defs = NULL;
   unsigned int i, dregno, end_dregno;
   unsigned int sregno = FIRST_PSEUDO_REGISTER;
   unsigned int end_sregno = FIRST_PSEUDO_REGISTER;
@@ -330,8 +330,11 @@ move_insn_for_shrink_wrap (basic_block bb, rtx_insn *insn,
       /* Check whether BB uses DEST or clobbers DEST.  We need to add
 	 INSN to BB if so.  Either way, DEST is no longer live on entry,
 	 except for any part that overlaps SRC (next loop).  */
+      if (!*split_p)
+	{
 	  bb_uses = &DF_LR_BB_INFO (bb)->use;
 	  bb_defs = &DF_LR_BB_INFO (bb)->def;
+	}
       if (df_live)
 	{
 	  for (i = dregno; i < end_dregno; i++)

gcc/testsuite/ChangeLog

 2018-04-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/85167
+	* gcc.dg/pr85167.c: New test.
+
 	PR tree-optimization/85156
 	* c-c++-common/pr85156.c: New test.
 	* gcc.c-torture/execute/pr85156.c: New test.

gcc/testsuite/gcc.dg/pr85167.c

+/* PR rtl-optimization/85167 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -w" } */
+
+struct A { long b; };
+int c, d, e;
+int bar (void);
+
+int
+foo (void)
+{
+  long g;
+  for (; g == c ? 0 : (e = 1); g = ((struct A *)g)->b)
+    if (bar ())
+      return d;
+}