1 files changed, 33 insertions, 4 deletions

diff --git a/eval/src/tests/ann/nns-l2.h b/eval/src/tests/ann/nns-l2.h
index cfa5fed704f..dcad5f1bda6 100644
--- a/eval/src/tests/ann/nns-l2.h
+++ b/eval/src/tests/ann/nns-l2.h
@@ -1,8 +1,36 @@
 // Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #pragma once
+#include <string.h>
 #include <vespa/vespalib/hwaccelrated/iaccelrated.h>
 
+template <typename T, size_t VLEN>
+static double hw_l2_sq_dist(const T * af, const T * bf, size_t sz)
+{   
+    constexpr const size_t OpsPerV = VLEN/sizeof(T);
+    typedef T V __attribute__ ((vector_size (VLEN), aligned(VLEN)));
+
+    const V * a = reinterpret_cast<const V *>(af);
+    const V * b = reinterpret_cast<const V *>(bf);
+
+    V tmp_diff;
+    V tmp_squa;
+    V tmp_sum;
+    memset(&tmp_sum, 0, sizeof(tmp_sum)); 
+
+    const size_t numOps = sz/OpsPerV;
+    for (size_t i = 0; i < numOps; ++i) {
+        tmp_diff = a[i] - b[i];
+        tmp_squa = tmp_diff * tmp_diff;
+        tmp_sum += tmp_squa;
+    }
+    double sum = 0;
+    for (size_t i = 0; i < OpsPerV; ++i) {
+        sum += tmp_sum[i];
+    }
+    return sum;
+}
+
 template <typename FltType = float>
 struct L2DistCalc {
     vespalib::hwaccelrated::IAccelrated::UP _hw;
@@ -11,7 +39,10 @@ struct L2DistCalc {
 
     using Arr = vespalib::ArrayRef<FltType>;
     using ConstArr = vespalib::ConstArrayRef<FltType>;
-    
+
+    double product(const FltType *v1, const FltType *v2, size_t sz) {
+        return _hw->dotProduct(v1, v2, sz);
+    }
     double product(ConstArr v1, ConstArr v2) {
         const FltType *p1 = v1.begin();
         const FltType *p2 = v2.begin();
@@ -28,9 +59,7 @@ struct L2DistCalc {
         return l2sq(tmp);
     }
     double l2sq_dist(ConstArr v1, ConstArr v2) {
-        std::vector<FltType> tmp;
-        tmp.resize(v1.size());
-        return l2sq_dist(v1, v2, Arr(tmp));
+        return hw_l2_sq_dist<FltType, 32>(v1.cbegin(), v2.cbegin(), v1.size());
     }
 };