From 452d6cf304ece0ecfe94f1371c5151e2376673de Mon Sep 17 00:00:00 2001
From: Jeff Muizelaar <jmuizelaar@mozilla.com>
Date: Wed, 15 Jul 2009 14:08:57 -0400
Subject: [PATCH] Bug 501428. SMIL: Optimize nsSMILKeySpline::CalcBezier.
 r=dholbert, r=longsonr

Eliminates the call to pow() and reduces the number of multiplications from 4
to 3.
---
 content/smil/nsSMILKeySpline.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/content/smil/nsSMILKeySpline.cpp b/content/smil/nsSMILKeySpline.cpp
index 2579a8a953e..0cee12bc7e6 100644
--- a/content/smil/nsSMILKeySpline.cpp
+++ b/content/smil/nsSMILKeySpline.cpp
@@ -78,7 +78,8 @@ nsSMILKeySpline::CalcBezier(double aT,
                             double aA1,
                             double aA2)
 {
-  return A(aA1, aA2) * pow(aT,3) + B(aA1, aA2)*aT*aT + C(aA1) * aT;
+  // use Horner's scheme to evaluate the Bezier polynomial
+  return ((A(aA1, aA2)*aT + B(aA1, aA2))*aT + C(aA1))*aT;
 }
 
 /*static*/ double