Better seed support for (random).

[bpt/emacs.git] / src / fns.c

diff --git a/src/fns.c b/src/fns.c
index f6acdca..2dee851 100644 (file)
--- a/src/fns.c
+++ b/src/fns.c
@@ -74,32 +74,16 @@ Other values of LIMIT are ignored.  */)
   (Lisp_Object limit)
 {
   EMACS_INT val;
-  Lisp_Object lispy_val;
 
   if (EQ (limit, Qt))
-    {
-      EMACS_TIME t = current_emacs_time ();
-      seed_random (getpid () ^ EMACS_SECS (t) ^ EMACS_NSECS (t));
-    }
+    init_random ();
+  else if (STRINGP (limit))
+    seed_random (SSDATA (limit), SBYTES (limit));
 
+  val = get_random ();
   if (NATNUMP (limit) && XFASTINT (limit) != 0)
-    {
-      /* Try to take our random number from the higher bits of VAL,
-        not the lower, since (says Gentzel) the low bits of `random'
-        are less random than the higher ones.  We do this by using the
-        quotient rather than the remainder.  At the high end of the RNG
-        it's possible to get a quotient larger than n; discarding
-        these values eliminates the bias that would otherwise appear
-        when using a large n.  */
-      EMACS_INT denominator = (INTMASK + 1) / XFASTINT (limit);
-      do
-       val = get_random () / denominator;
-      while (val >= XFASTINT (limit));
-    }
-  else
-    val = get_random ();
-  XSETINT (lispy_val, val);
-  return lispy_val;
+    val %= XFASTINT (limit);
+  return make_number (val);
 }
 \f
 /* Heuristic on how many iterations of a tight loop can be safely done