[FFmpeg-devel] [PATCH] Moves yuv2yuvX_sse3 to yasm, unrolls main loop and other small optimizations for ~20% speedup. AVX2 version is ready and tested, however, although local tests show a significant speed-up in this function using avx2 swscale code overall slows down probably due cpu frequency scaling.
Alan Kelly
alankelly at google.com
Tue Oct 27 10:57:21 EET 2020
Thanks for the review, I have made the required changes. As I have changed
the subject the patch is in a new thread.
On Fri, Oct 23, 2020 at 4:10 PM James Almer <jamrial at gmail.com> wrote:
> On 10/23/2020 10:17 AM, Alan Kelly wrote:
> > Fixed. The wrong step size was used causing a write passed the end of
> > the buffer. yuv2yuvX_mmxext is now called if there are any remaining
> pixels.
>
> Please fix the commit subject (It's too long and contains commentary),
> and keep comments about fixes between versions outside of the commit
> message body. You can manually place them after the --- below, or in a
> separate reply.
>
> > ---
> > libswscale/x86/Makefile | 1 +
> > libswscale/x86/swscale.c | 75 ++++----------------------
> > libswscale/x86/yuv2yuvX.asm | 105 ++++++++++++++++++++++++++++++++++++
> > 3 files changed, 116 insertions(+), 65 deletions(-)
> > create mode 100644 libswscale/x86/yuv2yuvX.asm
> >
> > diff --git a/libswscale/x86/Makefile b/libswscale/x86/Makefile
> > index 831d5359aa..bfe383364e 100644
> > --- a/libswscale/x86/Makefile
> > +++ b/libswscale/x86/Makefile
> > @@ -13,3 +13,4 @@ X86ASM-OBJS += x86/input.o
> \
> > x86/scale.o
> \
> > x86/rgb_2_rgb.o
> \
> > x86/yuv_2_rgb.o
> \
> > + x86/yuv2yuvX.o
> \
> > diff --git a/libswscale/x86/swscale.c b/libswscale/x86/swscale.c
> > index 3160fedf04..fec9fa22e0 100644
> > --- a/libswscale/x86/swscale.c
> > +++ b/libswscale/x86/swscale.c
> > @@ -197,80 +197,25 @@ void ff_updateMMXDitherTables(SwsContext *c, int
> dstY)
> > }
> >
> > #if HAVE_MMXEXT
> > +void ff_yuv2yuvX_sse3(const int16_t *filter, int filterSize,
> > + uint8_t *dest, int dstW,
> > + const uint8_t *dither, int offset);
> > +
> > static void yuv2yuvX_sse3(const int16_t *filter, int filterSize,
> > const int16_t **src, uint8_t *dest, int dstW,
> > const uint8_t *dither, int offset)
> > {
> > + int remainder = (dstW % 32);
> > + int pixelsProcessed = dstW - remainder;
> > if(((uintptr_t)dest) & 15){
> > yuv2yuvX_mmxext(filter, filterSize, src, dest, dstW, dither,
> offset);
> > return;
> > }
> > - filterSize--;
> > -#define MAIN_FUNCTION \
> > - "pxor %%xmm0, %%xmm0 \n\t" \
> > - "punpcklbw %%xmm0, %%xmm3 \n\t" \
> > - "movd %4, %%xmm1 \n\t" \
> > - "punpcklwd %%xmm1, %%xmm1 \n\t" \
> > - "punpckldq %%xmm1, %%xmm1 \n\t" \
> > - "punpcklqdq %%xmm1, %%xmm1 \n\t" \
> > - "psllw $3, %%xmm1 \n\t" \
> > - "paddw %%xmm1, %%xmm3 \n\t" \
> > - "psraw $4, %%xmm3 \n\t" \
> > - "movdqa %%xmm3, %%xmm4 \n\t" \
> > - "movdqa %%xmm3, %%xmm7 \n\t" \
> > - "movl %3, %%ecx \n\t" \
> > - "mov %0, %%"FF_REG_d"
> \n\t"\
> > - "mov (%%"FF_REG_d"), %%"FF_REG_S"
> \n\t"\
> > - ".p2align 4 \n\t" /*
> FIXME Unroll? */\
> > - "1: \n\t"\
> > - "movddup 8(%%"FF_REG_d"), %%xmm0 \n\t" /*
> filterCoeff */\
> > - "movdqa (%%"FF_REG_S", %%"FF_REG_c", 2), %%xmm2
> \n\t" /* srcData */\
> > - "movdqa 16(%%"FF_REG_S", %%"FF_REG_c", 2), %%xmm5
> \n\t" /* srcData */\
> > - "add $16, %%"FF_REG_d"
> \n\t"\
> > - "mov (%%"FF_REG_d"), %%"FF_REG_S"
> \n\t"\
> > - "test %%"FF_REG_S", %%"FF_REG_S"
> \n\t"\
> > - "pmulhw %%xmm0, %%xmm2 \n\t"\
> > - "pmulhw %%xmm0, %%xmm5 \n\t"\
> > - "paddw %%xmm2, %%xmm3 \n\t"\
> > - "paddw %%xmm5, %%xmm4 \n\t"\
> > - " jnz 1b \n\t"\
> > - "psraw $3, %%xmm3 \n\t"\
> > - "psraw $3, %%xmm4 \n\t"\
> > - "packuswb %%xmm4, %%xmm3 \n\t"\
> > - "movntdq %%xmm3, (%1, %%"FF_REG_c")
> \n\t"\
> > - "add $16, %%"FF_REG_c" \n\t"\
> > - "cmp %2, %%"FF_REG_c" \n\t"\
> > - "movdqa %%xmm7, %%xmm3 \n\t" \
> > - "movdqa %%xmm7, %%xmm4 \n\t" \
> > - "mov %0, %%"FF_REG_d"
> \n\t"\
> > - "mov (%%"FF_REG_d"), %%"FF_REG_S"
> \n\t"\
> > - "jb 1b \n\t"
> > -
> > - if (offset) {
> > - __asm__ volatile(
> > - "movq %5, %%xmm3 \n\t"
> > - "movdqa %%xmm3, %%xmm4 \n\t"
> > - "psrlq $24, %%xmm3 \n\t"
> > - "psllq $40, %%xmm4 \n\t"
> > - "por %%xmm4, %%xmm3 \n\t"
> > - MAIN_FUNCTION
> > - :: "g" (filter),
> > - "r" (dest-offset), "g" ((x86_reg)(dstW+offset)), "m"
> (offset),
> > - "m"(filterSize), "m"(((uint64_t *) dither)[0])
> > - : XMM_CLOBBERS("%xmm0" , "%xmm1" , "%xmm2" , "%xmm3" ,
> "%xmm4" , "%xmm5" , "%xmm7" ,)
> > - "%"FF_REG_d, "%"FF_REG_S, "%"FF_REG_c
> > - );
> > - } else {
> > - __asm__ volatile(
> > - "movq %5, %%xmm3 \n\t"
> > - MAIN_FUNCTION
> > - :: "g" (filter),
> > - "r" (dest-offset), "g" ((x86_reg)(dstW+offset)), "m"
> (offset),
> > - "m"(filterSize), "m"(((uint64_t *) dither)[0])
> > - : XMM_CLOBBERS("%xmm0" , "%xmm1" , "%xmm2" , "%xmm3" ,
> "%xmm4" , "%xmm5" , "%xmm7" ,)
> > - "%"FF_REG_d, "%"FF_REG_S, "%"FF_REG_c
> > - );
> > + ff_yuv2yuvX_sse3(filter, filterSize - 1, dest - offset,
> pixelsProcessed + offset, dither, offset);
> > + if(remainder > 0){
> > + yuv2yuvX_mmxext(filter, filterSize, src, dest + pixelsProcessed,
> remainder, dither, offset + pixelsProcessed);
> > }
> > + return;
> > }
> > #endif
> >
> > diff --git a/libswscale/x86/yuv2yuvX.asm b/libswscale/x86/yuv2yuvX.asm
> > new file mode 100644
> > index 0000000000..84727de599
> > --- /dev/null
> > +++ b/libswscale/x86/yuv2yuvX.asm
> > @@ -0,0 +1,105 @@
> >
> +;******************************************************************************
> > +;* x86-optimized yuv2yuvX
> > +;* Copyright 2020 Google LLC
> > +;*
> > +;* This file is part of FFmpeg.
> > +;*
> > +;* FFmpeg is free software; you can redistribute it and/or
> > +;* modify it under the terms of the GNU Lesser General Public
> > +;* License as published by the Free Software Foundation; either
> > +;* version 2.1 of the License, or (at your option) any later version.
> > +;*
> > +;* FFmpeg is distributed in the hope that it will be useful,
> > +;* but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > +;* Lesser General Public License for more details.
> > +;*
> > +;* You should have received a copy of the GNU Lesser General Public
> > +;* License along with FFmpeg; if not, write to the Free Software
> > +;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> 02110-1301 USA
> >
> +;******************************************************************************
> > +
> > +%include "libavutil/x86/x86util.asm"
> > +
> > +SECTION .text
> > +
> >
> +;-----------------------------------------------------------------------------
> > +; yuv2yuvX
> > +;
> > +; void ff_yuv2yuvX_<opt>(const int16_t *filter, int filterSize,
> > +; uint8_t *dest, int dstW,
> > +; const uint8_t *dither, int offset);
> > +;
> >
> +;-----------------------------------------------------------------------------
> > +
> > +%macro YUV2YUVX_FUNC 0
> > +cglobal yuv2yuvX, 6, 7, 16, filter, rsi, dest, dstW, dither, offset, src
> > +%if ARCH_X86_64
> > + movsxd dstWq, dstWd
> > + movsxd offsetq, offsetd
> > +%endif ; x86-64
> > + movq xmm3, [ditherq]
> > + cmp offsetd, 0
> > + jz .offset
> > +
> > + ; offset != 0 path.
> > + psrlq m5, m3, $18
> > + psllq m3, m3, $28
> > + por m3, m3, m5
> > +
> > +.offset:
> > +%if cpuflag(avx2)
> > + vperm2i128 m3, m3, m3, 0
> > +%endif ; avx2
> > +%if ARCH_X86_64
> > + movq xmm1, rsiq
> > +%else
> > + movd mm1, rsi
>
> What uses mm1 after this on x86_32?
>
> > +%endif
> > + vpbroadcastw m1, xmm1
>
> AVX2 instruction being used in the SSE3 version.
>
> > + pxor m0, m0, m0
> > + mov rsiq, filterq
> > + mov srcq, [rsiq]
> > + punpcklbw m3, m0
> > + psllw m1, m1, 3
> > + paddw m3, m3, m1
> > + psraw m7, m3, 4
> > +.outerloop:
> > + mova m4, m7
> > + mova m3, m7
> > + mova m6, m7
> > + mova m1, m7
> > +.loop:
> > + vpbroadcastq m0, [rsiq + 8]
>
> Same.
>
> > + pmulhw m2, m0, [srcq + offsetq * 2]
> > + pmulhw m5, m0, [srcq + offsetq * 2 + mmsize]
> > + paddw m3, m3, m2
> > + paddw m4, m4, m5
> > + pmulhw m2, m0, [srcq + offsetq * 2 + 2 * mmsize]
> > + pmulhw m5, m0, [srcq + offsetq * 2 + 3 * mmsize]
> > + paddw m6, m6, m2
> > + paddw m1, m1, m5
> > + add rsiq, $10
> > + mov srcq, [rsiq]
> > + test srcd, srcd
> > + jnz .loop
> > + psraw m3, m3, 3
> > + psraw m4, m4, 3
> > + psraw m6, m6, 3
> > + psraw m1, m1, 3
> > + packuswb m3, m3, m4
> > + packuswb m6, m6, m1
> > + mov srcq, [filterq]
> > + movntdq [destq + offsetq], m3
> > + movntdq [destq + offsetq + mmsize], m6
> > + add offsetq, mmsize * 2
> > + mov rsiq, filterq
> > + cmp offsetq, dstWq
> > + jb .outerloop
> > + REP_RET
> > +%endmacro
> > +
> > +INIT_XMM sse3
>
> The only SSE3 instruction was movddup, and you removed it. I assume the
> vpbroadcastq is meant to be it for the non-AVX2 version of the function.
>
> > +YUV2YUVX_FUNC
> > +INIT_YMM avx2
> > +YUV2YUVX_FUNC
> >
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
More information about the ffmpeg-devel
mailing list