diff --git a/ChangeLog b/ChangeLog
index fa6c85c860..43fa879666 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jun 11 21:05:09 2009  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* lib/cmath.rb (exp): omitted redundant function call.
+
 Thu Jun 11 17:49:33 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/bigdecimal/bigdecimal.c (gfCheckVal): never used.
diff --git a/lib/cmath.rb b/lib/cmath.rb
index 31c5a59c99..d9e53f361a 100644
--- a/lib/cmath.rb
+++ b/lib/cmath.rb
@@ -28,8 +28,9 @@ module CMath
     if z.real?
       exp!(z)
     else
-      Complex(exp!(z.real) * cos!(z.imag),
-	      exp!(z.real) * sin!(z.imag))
+      ere = exp!(z.real)
+      Complex(ere * cos!(z.imag),
+	      ere * sin!(z.imag))
     end
   end
 
@@ -94,7 +95,7 @@ module CMath
     if z.real?
       tan!(z)
     else
-      sin(z)/cos(z)
+      sin(z) / cos(z)
     end
   end
 
@@ -156,14 +157,6 @@ module CMath
     end
   end
 
-  def acosh(z)
-    if z.real? and z >= 1
-      acosh!(z)
-    else
-      log(z + sqrt(z * z - 1.0))
-    end
-  end
-
   def asinh(z)
     if z.real?
       asinh!(z)
@@ -172,6 +165,14 @@ module CMath
     end
   end
 
+  def acosh(z)
+    if z.real? and z >= 1
+      acosh!(z)
+    else
+      log(z + sqrt(z * z - 1.0))
+    end
+  end
+
   def atanh(z)
     if z.real? and z >= -1 and z <= 1
       atanh!(z)