varray_sum_mv: added OpenMP pragma.

src/varray.cc

@@ -582,6 +582,14 @@ template <typename T>
 double
 varray_sum_mv(const size_t len, const Varray<T> &v, const T missval)
 {
+  auto f_sum_mv = [](const auto a, const auto mv_a, auto &sum, auto &nvals, auto is_EQ) {
+    if (!is_EQ(a, mv_a))
+      {
+        sum += a;
+        nvals++;
+      }
+  };
+
   assert(len > 0);
   assert(v.size() > 0);
   assert(len <= v.size());
@@ -591,21 +599,17 @@ varray_sum_mv(const size_t len, const Varray<T> &v, const T missval)
 
   if (std::isnan(missval))
     {
-      for (size_t i = 0; i < len; ++i)
-        if (!DBL_IS_EQUAL(v[i], missval))
-          {
-            sum += v[i];
-            nvals++;
-          }
+#ifdef HAVE_OPENMP4
+#pragma omp parallel for default(shared) schedule(static) reduction(+ : sum,nvals)
+#endif
+      for (size_t i = 0; i < len; ++i) f_sum_mv(v[i], missval, sum, nvals, dbl_is_equal);
     }
   else
     {
-      for (size_t i = 0; i < len; ++i)
-        if (IS_NOT_EQUAL(v[i], missval))
-          {
-            sum += v[i];
-            nvals++;
-          }
+#ifdef HAVE_OPENMP4
+#pragma omp parallel for default(shared) schedule(static) reduction(+ : sum,nvals)
+#endif
+      for (size_t i = 0; i < len; ++i) f_sum_mv(v[i], missval, sum, nvals, is_equal);
     }
 
   if (!nvals) sum = missval;