[x265] [PATCH] asm: intrapred dc8 sse2 high bit

[dave]

On 02/26/2015 02:43 PM, Steve Borho wrote:
> On 02/26, dave wrote:
>> On 02/25/2015 05:59 AM, chen wrote:
>>> At 2015-02-25 08:16:44,dtyx265 at gmail.com wrote:
>>>> # HG changeset patch
>>>> # User David T Yuen <dtyx265 at gmail.com>
>>>> # Date 1424823199 28800
>>>> # Node ID bd1d713da87bb1e3022c80f462398bd78a95ce48
>>>> # Parent  644d27ca0b197455393171ba705b1190f3d9b420
>>>> asm: intrapred dc8 sse2 high bit
>>>>
>>>> This replaces c code for systems using ssse3 to sse2 processors
>>>> The code is backported from intrapred dc8 sse4 high bit
>>>>
>>>> ./test/TestBench --testbench intrapred | grep 8x8
>>>> intra_dc_8x8[f=0]	1.62x 	 443.94   	 717.32
>>>> intra_dc_8x8[f=1]	1.59x 	 729.98   	 1157.66
>>>>
>>>> diff -r 644d27ca0b19 -r bd1d713da87b source/common/x86/asm-primitives.cpp
>>>> --- a/source/common/x86/asm-primitives.cpp	Tue Feb 24 14:47:01 2015 -0800
>>>> +++ b/source/common/x86/asm-primitives.cpp	Tue Feb 24 16:13:19 2015 -0800
>>>> @@ -864,6 +864,7 @@
>>>>          ALL_LUMA_TU_S(transpose, transpose, sse2);
>>>>
>>>>          p.cu[BLOCK_4x4].intra_pred[DC_IDX] = x265_intra_pred_dc4_sse2;
>>>> +        p.cu[BLOCK_8x8].intra_pred[DC_IDX] = x265_intra_pred_dc8_sse2;
>>>>
>>>>          p.cu[BLOCK_4x4].sse_ss = x265_pixel_ssd_ss_4x4_mmx2;
>>>>          ALL_LUMA_CU(sse_ss, pixel_ssd_ss, sse2);
>>>> diff -r 644d27ca0b19 -r bd1d713da87b source/common/x86/intrapred16.asm
>>>> --- a/source/common/x86/intrapred16.asm	Tue Feb 24 14:47:01 2015 -0800
>>>> +++ b/source/common/x86/intrapred16.asm	Tue Feb 24 16:13:19 2015 -0800
>>>> @@ -86,6 +86,7 @@
>>>> cextern pw_8
>>>> cextern pw_16
>>>> cextern pw_1023
>>>> +cextern pd_2
>>>> cextern pd_16
>>>> cextern pd_32
>>>> cextern pw_4096
>>>> @@ -166,6 +167,89 @@
>>>> ;-----------------------------------------------------------------------------------
>>>> ; void intra_pred_dc(pixel* dst, intptr_t dstStride, pixel* above, int, int filter)
>>>> ;-----------------------------------------------------------------------------------
>>>> +INIT_XMM sse2
>>>> +cglobal intra_pred_dc8, 5, 8, 2
>>>> +    add             r2,            2
>>>> +    add             r1,            r1
>>>> +    movu            m0,            [r2 + 32]
>>>> +    movu            m1,            [r2]
>>>> +
>>>> +    paddw           m0,            m1
>>>> +    movhlps         m1,            m0
>>>> +    paddw           m0,            m1
>>>> +    pshufd          m1,            m0, 1
>>>> +    paddw           m0,            m1
>>>> +    pmaddwd         m0,            [pw_1]
>>>> +
>>>> +    paddw           m0,            [pw_8]
>>>> +    psraw           m0,            4              ; sum = sum / 16
>>>> +    pshuflw         m0,            m0, 0
>>>> +    pshufd          m0,            m0, 0          ; m0 = word [dc_val ...]
>>>> +
>>>> +    test            r4d,           r4d
>>>> +
>>>> +    ; store DC 8x8
>>>> +    lea             r6,            [r1 + r1 * 2]
>>>> +    lea             r5,            [r6 + r1 * 2]
>>>> +    lea             r7,            [r6 + r1 * 4]
>>>> +    movu            [r0],          m0
>>>> +    movu            [r0 + r1],     m0
>>>> +    movu            [r0 + r1 * 2], m0
>>>> +    movu            [r0 + r6],     m0
>>>> +    movu            [r0 + r1 * 4], m0
>>>> +    movu            [r0 + r5],     m0
>>>> +    movu            [r0 + r6 * 2], m0
>>>> +    movu            [r0 + r7],     m0
>>>> +
>>>> +    ; Do DC Filter
>>>> +    jz              .end
>>>> +    mova            m1,            [pd_2]
>>>> +    pmullw          m1,            m0
>>> [x x x x] * [0 2 0 2] = [0 dc*2 0 dc*2], am I right?
>>> Why not PSLL?
>> For some reason using psllw in place of pmullw hurts performance of
>> unfiltered in 8 and 10 bit far more than you would expect for such a
>> small change.  8 bit speed is cut by more than half
>>
>> ./test/TestBench --testbench intrapred | grep 8x8
>>
>> intra_dc_8x8[f=0]    1.84x      492.58        906.63
>> intra_dc_8x8[f=1]    2.38x      537.68        1280.02
>>
>>   and 10 bit is barely faster than c code.
>>
>> ./test/TestBench --testbench intrapred | grep 8x8
>> intra_dc_8x8[f=0]    1.06x      677.54        719.80
>> intra_dc_8x8[f=1]    1.60x      725.05        1157.54
>>
>> I will resubmit with other adjustments
> You may find this useful, if you have not seen it before:
>
> https://software.intel.com/en-us/articles/intel-architecture-code-analyzer
>
Thanks!  I am running an athlon cpu but it looks like amd has a similar 
tool.

http://developer.amd.com/tools-and-sdks/opencl-zone/codexl/

It will be interesting to see how each one views the same code.