core2: mmx2=154 sse2=73 ssse3=66 (cycles)
k8: mmx2=179 sse2=149
p4: mmx2=284 sse2=194


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9003 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b