On 02/21/2012 05:02 PM, Christophe Gisquet wrote: > Hi, > > this is very minor, and I'm not even sure it can be said to be a win, > but still... > > Christophe > > > 0003-x86-dsputil-simplify-scalarproduct_float_sse.patch > > > From 4338b6b7a41c5beeb368410edb31b6439725a65e Mon Sep 17 00:00:00 2001 > From: Christophe GISQUET <[email protected]> > Date: Tue, 21 Feb 2012 22:43:27 +0100 > Subject: [PATCH 3/3] x86 dsputil: simplify scalarproduct_float_sse > > The mov and the shuffle can be performed in one instruction by using a > different shuffle operation. Timing difference is not measurable. > --- > libavcodec/x86/dsputil_yasm.asm | 3 +-- > 1 files changed, 1 insertions(+), 2 deletions(-) > > diff --git a/libavcodec/x86/dsputil_yasm.asm b/libavcodec/x86/dsputil_yasm.asm > index 09940d1..ca3ec18 100644 > --- a/libavcodec/x86/dsputil_yasm.asm > +++ b/libavcodec/x86/dsputil_yasm.asm > @@ -472,8 +472,7 @@ cglobal scalarproduct_float_sse, 3,3,2, v1, v2, offset > js .loop > movhlps xmm1, xmm0 > addps xmm0, xmm1 > - movss xmm1, xmm0 > - shufps xmm0, xmm0, 1 > + pshufd xmm1, xmm0, 1 > addss xmm0, xmm1 > %if ARCH_X86_64 == 0 > movd r0m, xmm0
pshufd is sse2 not sse -Justin _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
