[x265] Fwd: [PATCH] asm: luma_vpp[16x16] in avx2: improve 2141c->1488c

[chen]

I will try to give you a demo later, you can process other mode (x64 only)

At 2014-11-19 20:31:29,"Divya Manivannan" <divya at multicorewareinc.com> wrote:

Hello Chen,


I have tried processing one row in avx2 for 32 bit. But the performance is less than processing half of the row.
I have got 1891 cycles for one row processing but 1488 cycles for processing half row.
Herewith I have attached the algorithm which I have tried. 


Regards,
Divya


On Tue, Nov 18, 2014 at 11:29 PM, chen <chenm003 at 163.com> wrote:

 


At 2014-11-18 19:34:53,"Divya Manivannan" <divya at multicorewareinc.com> wrote:



---------- Forwarded message ----------
From: chen<chenm003 at 163.com>
Date: Mon, Nov 17, 2014 at 9:54 PM
Subject: Re: [x265] [PATCH] asm: luma_vpp[16x16] in avx2: improve 2141c->1488c
To: Development for x265 <x265-devel at videolan.org>



 

At 2014-11-17 19:14:55,"Divya Manivannan" <divya at multicorewareinc.com> wrote:
># HG changeset patch
># User Divya Manivannan divya at multicorewareinc.com>
># Date 1416222868 -19800
>#      Mon Nov 17 16:44:28 2014 +0530
># Node ID 95571420e32c02f51d41fc45d286a2619a5052e5
># Parent  5fec38f8c75606ddf4d5b7c9244dfd373892af5d
>asm: luma_vpp[16x16] in avx2: improve 2141c->1488c
>
 INIT_YMM avx2
>-cglobal interp_8tap_vert_pp_8x8, 4,7,7
>+cglobal interp_8tap_vert_pp_8x8, 4, 7, 7
>     mov             r4d, r4m
>     shl             r4d, 7
>     lea             r5, [r1 * 3]
>@@ -3875,6 +3875,57 @@
>     RET
> %endmacro
> 
>+INIT_YMM avx2
>+cglobal interp_8tap_vert_pp_16x16, 4, 7, 7, 0-gprsize

you just use dword local stack
[Divya] I couldnt understand why I need to use dword local stack?
[MC] because "dec dword [rsp]", you really use dword.

 
>+    mov             r4d, r4m
>+    shl             r4d, 7
>+    lea             r5, [r1 * 3]
>+    sub             r0, r5
>+
>+%ifdef PIC
>+    lea             r5, [tab_LumaCoeffVer_32]
>+    lea             r5, [r5 + r4]

same before
>+%else
>+    lea             r5, [tab_LumaCoeffVer_32 + r4]
>+%endif
>+
>+    mov             dword [rsp], 2
>+
>+.loopH:
>+    mov             r4d, 2
>+.loopW:
>+    PROCESS_LUMA_AVX2_W8_8R

AVX2 can processing one row, could you try these mode? 
>+    lea             r6, [r2]
>+    pmulhrsw        m5, [pw_512]                    ; m5 = word: row 0, row 1
>+    pmulhrsw        m2, [pw_512]                    ; m2 = word: row 2, row 3
>+    pmulhrsw        m1, [pw_512]                    ; m1 = word: row 4, row 5
>+    pmulhrsw        m4, [pw_512]                    ; m4 = word: row 6, row 7
>+    packuswb        m5, m2
>+    packuswb        m1, m4
>+    vextracti128    xm2, m5, 1
>+    vextracti128    xm4, m1, 1
>+    movq            [r6], xm5
>+    movq            [r6 + r3], xm2
>+    lea             r6, [r6 + r3 * 2]
>+    movhps          [r6], xm5
>+    movhps          [r6 + r3], xm2
>+    lea             r6, [r6 + r3 * 2]
>+    movq            [r6], xm1
>+    movq            [r6 + r3], xm4
>+    lea             r6, [r6 + r3 * 2]
>+    movhps          [r6], xm1
>+    movhps          [r6 + r3], xm4
>+
>+    add             r0, 8
>+    add             r2, 8
>+    dec             r4d
>+    jnz             .loopW
>+    lea             r2, [r2 + r3 * 8 - 16]
>+    lea             r0, [r0 + r1 * 8 - 16]
>+    dec             dword [rsp]

code is right, but I suggest use a macro to improve x64 perf
[Divya]  I couldnt understand this macro to improve x64 performance.
[MC] most time, memory is slower, in x64 mode, we have 16 register, so you can replace memory operator to register
 
>+    jnz             .loopH
>+    RET
>+
> ;-------------------------------------------------------------------------------------------------------------
> ; void interp_8tap_vert_pp_12x16(pixel *src, intptr_t srcStride, pixel *dst, intptr_t dstStride, int coeffIdx)
> ;-------------------------------------------------------------------------------------------------------------
>_______________________________________________
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>x265-devel at videolan.org
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