1 files changed, 40 insertions, 0 deletions
diff --git a/vespalib/src/tests/util/hamming/hamming_benchmark.cpp b/vespalib/src/tests/util/hamming/hamming_benchmark.cpp
new file mode 100644
index 00000000000..b6393dcd1b7
--- /dev/null
+++ b/vespalib/src/tests/util/hamming/hamming_benchmark.cpp
@@ -0,0 +1,40 @@
+// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include <vespa/vespalib/util/binary_hamming_distance.h>
+#include <vector>
+#include <cstdlib>
+#include <cstdint>
+#include <cstdio>
+
+using namespace vespalib;
+
+int main(int argc, char* argv[]) {
+    size_t vector_length = 1024/8;
+    size_t num_vectors = 1;
+    size_t num_reps = 100000000;
+
+    if (argc > 2) {
+        vector_length = atol(argv[2])/8;
+    }
+    if (argc > 3) {
+        num_reps = atol(argv[3]);
+    }
+    if (argc > 4) {
+        num_vectors = atol(argv[4]);
+    }
+
+    std::vector<uint8_t> center(vector_length);
+    std::vector<uint8_t> vectors(num_vectors*vector_length);
+    srand(13);
+    for (uint8_t & v : center) { v = rand(); }
+    for (uint8_t & v : vectors) { v = rand(); }
+    uint64_t sum(0);
+    for (size_t i=0; i < num_reps; i++) {
+        for (size_t j(0); j < num_vectors; j++) {
+            sum += binary_hamming_distance(center.data(), vectors.data() + j*vector_length, vector_length);
+        }
+    }
+
+    printf("%lu vectors of %lu bits, repeated %lu times. Sum of distances = %lu\n", num_vectors, vector_length*8, num_reps, sum);
+    return 0;
+}