diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index be98abe0515..b2aec1afa54 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2017-07-28  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/81578
+	* tree-parloops.c (build_new_reduction): Bail out if
+	reduction_code isn't one of the standard OpenMP reductions.
+	Move the details printing after that decision.
+
 2017-07-27  Peter Bergner  <bergner@vnet.ibm.com>
 
 	* config/rs6000/predicates.md (volatile_mem_operand): Remove code
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0fa0da85deb..19f10701053 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-07-28  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/81578
+	* gcc.dg/pr81578.c: New test.
+
 2017-07-28  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/81573
diff --git a/gcc/testsuite/gcc.dg/pr81578.c b/gcc/testsuite/gcc.dg/pr81578.c
new file mode 100644
index 00000000000..a6ef77f20c0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr81578.c
@@ -0,0 +1,12 @@
+/* PR tree-optimization/81578 */
+/* { dg-do compile { target pthread } } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+int
+foo (int *x)
+{
+  int i, r = 1;
+  for (i = 0; i != 1024; i++)
+    r *= x[i] < 0;
+  return r;
+}
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index 470964bebf7..538932e50bf 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -2475,6 +2475,32 @@ build_new_reduction (reduction_info_table_type *reduction_list,
 
   gcc_assert (reduc_stmt);
 
+  if (gimple_code (reduc_stmt) == GIMPLE_PHI)
+    {
+      tree op1 = PHI_ARG_DEF (reduc_stmt, 0);
+      gimple *def1 = SSA_NAME_DEF_STMT (op1);
+      reduction_code = gimple_assign_rhs_code (def1);
+    }
+  else
+    reduction_code = gimple_assign_rhs_code (reduc_stmt);
+  /* Check for OpenMP supported reduction.  */
+  switch (reduction_code)
+    {
+    case PLUS_EXPR:
+    case MULT_EXPR:
+    case MAX_EXPR:
+    case MIN_EXPR:
+    case BIT_IOR_EXPR:
+    case BIT_XOR_EXPR:
+    case BIT_AND_EXPR:
+    case TRUTH_OR_EXPR:
+    case TRUTH_XOR_EXPR:
+    case TRUTH_AND_EXPR:
+      break;
+    default:
+      return;
+    }
+
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
       fprintf (dump_file,
@@ -2483,16 +2509,6 @@ build_new_reduction (reduction_info_table_type *reduction_list,
       fprintf (dump_file, "\n");
     }
 
-  if (gimple_code (reduc_stmt) == GIMPLE_PHI)
-    {
-      tree op1 = PHI_ARG_DEF (reduc_stmt, 0);
-      gimple *def1 = SSA_NAME_DEF_STMT (op1);
-      reduction_code = gimple_assign_rhs_code (def1);
-    }
-
-  else
-    reduction_code = gimple_assign_rhs_code (reduc_stmt);
-
   new_reduction = XCNEW (struct reduction_info);
 
   new_reduction->reduc_stmt = reduc_stmt;