From: Michal Krol <michal@tungstengraphics.com>
Date: Wed, 12 Nov 2008 18:01:46 +0000 (+0100)
Subject: util: Optimise log2().
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c5ba8ba9182a6946ee489241738457b1370b3c77;p=mesa.git

util: Optimise log2().
---

diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index 62272110ce3..fdaec8df823 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -163,7 +163,8 @@ static INLINE float logf( float f )
 
 static INLINE double log2( double x )
 {
-   return log( x ) / log( 2.0 );
+   const double invln2 = 1.442695041;
+   return log( x ) * invln2;
 }
 
 #else