covariance-matrix.c: (covariance_accumulator_hash) For categorical

variables, eliminate temporary string by using hsh_hash_bytes and XOR.

diff --git a/src/math/covariance-matrix.c b/src/math/covariance-matrix.c
index 88b85051d87eb96d0547993db351b6a633788190..c419ce02e8b2357a868526aff9147f172b1125d7 100644 (file)
--- a/src/math/covariance-matrix.c
+++ b/src/math/covariance-matrix.c
@@ -350,15 +350,10 @@ covariance_accumulator_hash (const void *h, const void *aux)
     }
   if (var_is_alpha (v_max) && var_is_alpha (v_min))
     {
-      unsigned int tmp;
-      char *x =
-       xnmalloc (1 + var_get_width (v_max) + var_get_width (v_min),
-                 sizeof (*x));
-      strncpy (x, val_max->s, var_get_width (v_max));
-      strncat (x, val_min->s, var_get_width (v_min));
-      tmp = *n_vars * (*n_vars + 1 + idx_max) + idx_min + hsh_hash_string (x);
-      free (x);
-      return tmp;
+      unsigned tmp = hsh_hash_bytes (val_max, var_get_width (v_max));
+      tmp ^= hsh_hash_bytes (val_min, var_get_width (v_min));
+      tmp += *n_vars * (*n_vars + 1 + idx_max) + idx_min;
+      return (size_t) tmp;
     }
   return -1u;
 }