Convert from double to signed data type for reference hamming distance.

1 files changed, 2 insertions, 2 deletions

diff --git a/eval/src/vespa/eval/eval/hamming_distance.h b/eval/src/vespa/eval/eval/hamming_distance.h
index 50c59c46a60..e7cfc88661d 100644
--- a/eval/src/vespa/eval/eval/hamming_distance.h
+++ b/eval/src/vespa/eval/eval/hamming_distance.h
@@ -5,8 +5,8 @@
 namespace vespalib::eval {
 
 inline double hamming_distance(double a, double b) {
-    uint8_t x = (uint8_t) a;
-    uint8_t y = (uint8_t) b;
+    uint8_t x = (uint8_t) (int8_t) a;
+    uint8_t y = (uint8_t) (int8_t) b;
     return __builtin_popcount(x ^ y);
 }