Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization

[Li, Liang Z]

> > Eric, thanks for you information. I didn't notice that discussion before.
> >
> >
> > I rewrite the buffer_find_nonzero_offset() with the 'bool memeqzero4_paolo
> length'
> > then write a test program to check a large amount of zero pages, and
> > use the 'time' to recode the time takes by different optimization.
> > Test result is like this:
> >
> > SSE2:
> > ------------------------------------------------------
> >               |            test 1         |     test 2
> > ----------------------------------------------------
> > Time(S):|       13.696            | 13.533
> > ------------------------------------------------
> >
> >
> > AVX2:
> > -------------------------------------------
> >               |        test 1     | test 2
> > -------------------------------------------
> > Time (S):|      10.583      |  10.306
> > -------------------------------------------
> >
> > memeqzero4_paolo:
> > ---------------------------------------
> >               |        test 1     | test 2
> > ---------------------------------------
> > Time (S):|      9.718     |  9.817
> > ----------------------------------------
> >
> >
> > Paolo's implementation has the best performance. It seems that we can
> > remove the SSE2 related Intrinsics.
> 
> How should I understand that comment?  That you are about to send an email
> to remove the sse2 support and that I can forget about this patch?
> 
> Thanks, Juan.
> 

I don't know Paolo's opinion about how to deal with the SSE2 Intrinsics, he is 
the author. From my personal view, 
now that we have found a better way, why to use such low level SSE2/AVX2 
Intrinsics. I don't know if someone else
is working on this. if not, and the related maintainer agrees to remove them, I 
am happy to send out a new patch.

Let's forget my patch at the moment.

Liang