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Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization |
Date: |
Tue, 10 Nov 2015 10:30:26 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 |
On 10/11/2015 10:13, Juan Quintela wrote:
>> > 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.
Note that you can simplify my implementation a lot, because
buffer_find_nonzero_offset already assumes that the buffer is aligned to
sizeof(VECTYPE), i.e. 16 bytes. For example you can just check the
first 4 unsigned longs against zero and then call memcmp.
Paolo
> 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?
- Re: [Qemu-devel] [v2 1/2] cutils: add avx2 instruction optimization, (continued)
- Re: [Qemu-devel] [v2 1/2] cutils: add avx2 instruction optimization, Paolo Bonzini, 2015/11/12
- Re: [Qemu-devel] [v2 1/2] cutils: add avx2 instruction optimization, Li, Liang Z, 2015/11/12
- Re: [Qemu-devel] [v2 1/2] cutils: add avx2 instruction optimization, Juan Quintela, 2015/11/12
- Re: [Qemu-devel] [v2 1/2] cutils: add avx2 instruction optimization, Li, Liang Z, 2015/11/12
- Re: [Qemu-devel] [v2 1/2] cutils: add avx2 instruction optimization, Paolo Bonzini, 2015/11/13
- Re: [Qemu-devel] [v2 1/2] cutils: add avx2 instruction optimization, Richard Henderson, 2015/11/12
[Qemu-devel] [v2 2/2] configure: add options to config avx2, Liang Li, 2015/11/09
Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Eric Blake, 2015/11/09
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Li, Liang Z, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Juan Quintela, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization,
Paolo Bonzini <=
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Li, Liang Z, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Paolo Bonzini, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Li, Liang Z, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Paolo Bonzini, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Li, Liang Z, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Paolo Bonzini, 2015/11/10
- Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Li, Liang Z, 2015/11/10
Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Li, Liang Z, 2015/11/11
Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Paolo Bonzini, 2015/11/12
Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization, Li, Liang Z, 2015/11/12