From: Michael Niedermayer <michaelni@gmx.at>
Date: Thu, 22 Mar 2007 00:52:49 +0000 (+0000)
Subject: optimize bessel function instead of trusting gcc to do trivial optimizations (as... 
X-Git-Tag: v0.5~9572
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=50df67d3b517c88089613458d85e2154f99ecf78;p=coroid%2Fffmpeg_saccubus.git

optimize bessel function instead of trusting gcc to do trivial optimizations (as gcc doesnt ...)

Originally committed as revision 8474 to svn://svn.ffmpeg.org/ffmpeg/trunk
---

diff --git a/libavcodec/resample2.c b/libavcodec/resample2.c
index ebda7e5a8..70d8a1d95 100644
--- a/libavcodec/resample2.c
+++ b/libavcodec/resample2.c
@@ -71,9 +71,10 @@ static double bessel(double x){
     double t=1;
     int i;
 
+    x= x*x/4;
     for(i=1; i<50; i++){
-        t *= i;
-        v += pow(x*x/4, i)/(t*t);
+        t *= x/(i*i);
+        v += t;
     }
     return v;
 }