[FFmpeg-devel] [PATCH] lavc/vc1dsp: R-V V inv_trans
Rémi Denis-Courmont
remi at remlab.net
Sun Dec 3 19:17:39 EET 2023
Le sunnuntaina 3. joulukuuta 2023, 16.40.08 EET flow gg a écrit :
> c910
> vc1dsp.vc1_inv_trans_4x4_dc_c: 84.0
> vc1dsp.vc1_inv_trans_4x4_dc_rvv_i32: 74.0
> vc1dsp.vc1_inv_trans_4x8_dc_c: 150.2
> vc1dsp.vc1_inv_trans_4x8_dc_rvv_i32: 83.5
> vc1dsp.vc1_inv_trans_8x4_dc_c: 129.0
> vc1dsp.vc1_inv_trans_8x4_dc_rvv_i64: 75.7
> vc1dsp.vc1_inv_trans_8x8_dc_c: 254.7
> vc1dsp.vc1_inv_trans_8x8_dc_rvv_i64: 90.5
The code below uses fractional multipliers, so I infer that the benchmarked
code was significantly different, and the measurements are not really worth the
bother.
I know that supply is a problem at the moment, but I if you are going to keep
this up, I would hope that ISCAS can get you access to an RVV 1.0 board.
In-line...
> diff --git a/libavcodec/riscv/vc1dsp_init.c b/libavcodec/riscv/vc1dsp_init.c
> new file mode 100644
> index 0000000000..88e0434f0e
> --- /dev/null
> +++ b/libavcodec/riscv/vc1dsp_init.c
> @@ -0,0 +1,47 @@
> +/*
> + * Copyright (c) 2023 Institue of Software Chinese Academy of Sciences
> (ISCAS).
> + *
> + * 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 <stdint.h>
> +
> +#include "libavutil/attributes.h"
> +#include "libavutil/cpu.h"
> +#include "libavutil/riscv/cpu.h"
> +#include "libavcodec/vc1.h"
> +
> +void ff_vc1_inv_trans_8x8_dc_rvv(uint8_t *dest, ptrdiff_t stride, int16_t
> *block);
> +void ff_vc1_inv_trans_4x8_dc_rvv(uint8_t *dest, ptrdiff_t stride, int16_t
> *block);
> +void ff_vc1_inv_trans_8x4_dc_rvv(uint8_t *dest, ptrdiff_t stride, int16_t
> *block);
> +void ff_vc1_inv_trans_4x4_dc_rvv(uint8_t *dest, ptrdiff_t stride, int16_t
> *block);
> +
> +av_cold void ff_vc1dsp_init_riscv(VC1DSPContext *dsp)
> +{
> +#if HAVE_RVV
> + int flags = av_get_cpu_flags();
> +
> + if (flags & AV_CPU_FLAG_RVV_I64) {
> + dsp->vc1_inv_trans_8x8_dc = ff_vc1_inv_trans_8x8_dc_rvv;
> + dsp->vc1_inv_trans_8x4_dc = ff_vc1_inv_trans_8x4_dc_rvv;
> + }
> + if (flags & AV_CPU_FLAG_RVV_I32) {
> + dsp->vc1_inv_trans_4x8_dc = ff_vc1_inv_trans_4x8_dc_rvv;
> + dsp->vc1_inv_trans_4x4_dc = ff_vc1_inv_trans_4x4_dc_rvv;
> + }
Probably missing VLENB checks.
> +#endif
> +}
> diff --git a/libavcodec/riscv/vc1dsp_rvv.S b/libavcodec/riscv/vc1dsp_rvv.S
> new file mode 100644
> index 0000000000..8a6b27192a
> --- /dev/null
> +++ b/libavcodec/riscv/vc1dsp_rvv.S
> @@ -0,0 +1,123 @@
> +/*
> + * Copyright (c) 2023 Institue of Software Chinese Academy of Sciences
> (ISCAS).
> + *
> + * 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/riscv/asm.S"
> +
> +func ff_vc1_inv_trans_8x8_dc_rvv, zve64x
> + lh t2, (a2)
> + li t1, 3
> + mul t2, t2, t1
You can multiply by 3, 5 or 9 with shift-and-add. By 12 with shift-and-add
then shift, and by 17 with shift then add. You don't need multiplications.
> + addi t2, t2, 1
> + srai t2, t2, 1
> + mul t2, t2, t1
> + addi t2, t2, 16
> + srai t2, t2, 5
> + vsetivli zero, 8, e8, mf2, ta, ma
> + vlse64.v v0, (a0), a1
> + li t0, 8*8
> + vsetvli zero, t0, e16, m8, ta, ma
> + vmv.v.x v8, t2
Do you really need to splat? Can't .vx or .wx be used instead?
> + vsetvli zero, t0, e8, m4, ta, ma
> + vwaddu.wv v8, v8, v0
> + vsetvli zero, t0, e16, m8, ta, ma
> + vmax.vx v8, v8, zero
> + vsetvli zero, t0, e8, m4, ta, ma
> + vnclipu.wi v0, v8, 0
> + vsetivli zero, 8, e8, mf2, ta, ma
> + vsse64.v v0, (a0), a1
> + ret
> +endfunc
> +
> +func ff_vc1_inv_trans_4x8_dc_rvv, zve32x
> + lh t2, (a2)
> + li t1, 17
> + mul t2, t2, t1
> + addi t2, t2, 4
> + srai t2, t2, 3
> + li t1, 12
> + mul t2, t2, t1
> + addi t2, t2, 64
> + srai t2, t2, 7
> + vsetivli zero, 8, e8, mf2, ta, ma
> + vlse32.v v0, (a0), a1
> + li t0, 4*8
> + vsetvli zero, t0, e16, m4, ta, ma
> + vmv.v.x v4, t2
> + vsetvli zero, t0, e8, m2, ta, ma
> + vwaddu.wv v4, v4, v0
> + vsetvli zero, t0, e16, m4, ta, ma
> + vmax.vx v4, v4, zero
> + vsetvli zero, t0, e8, m2, ta, ma
> + vnclipu.wi v0, v4, 0
> + vsetivli zero, 8, e8, mf2, ta, ma
> + vsse32.v v0, (a0), a1
> + ret
> +endfunc
> +
> +func ff_vc1_inv_trans_8x4_dc_rvv, zve64x
> + lh t2, (a2)
> + li t1, 3
> + mul t2, t2, t1
> + addi t2, t2, 1
> + srai t2, t2, 1
> + li t1, 17
> + mul t2, t2, t1
> + addi t2, t2, 64
> + srai t2, t2, 7
> + vsetivli zero, 8, e8, mf2, ta, ma
> + vlse64.v v0, (a0), a1
> + li t0, 8*4
> + vsetvli zero, t0, e16, m4, ta, ma
> + vmv.v.x v4, t2
> + vsetvli zero, t0, e8, m2, ta, ma
> + vwaddu.wv v4, v4, v0
> + vsetvli zero, t0, e16, m4, ta, ma
> + vmax.vx v4, v4, zero
> + vsetvli zero, t0, e8, m2, ta, ma
> + vnclipu.wi v0, v4, 0
> + vsetivli zero, 8, e8, mf2, ta, ma
> + vsse64.v v0, (a0), a1
> + ret
> +endfunc
> +
> +func ff_vc1_inv_trans_4x4_dc_rvv, zve32x
> + lh t2, (a2)
> + li t1, 17
> + mul t2, t2, t1
> + addi t2, t2, 4
> + srai t2, t2, 3
> + mul t2, t2, t1
> + addi t2, t2, 64
> + srai t2, t2, 7
> + vsetivli zero, 4, e8, mf2, ta, ma
> + vlse32.v v0, (a0), a1
> + li t0, 4*4
> + vsetvli zero, t0, e16, m2, ta, ma
> + vmv.v.x v2, t2
> + vsetvli zero, t0, e8, m1, ta, ma
> + vwaddu.wv v2, v2, v0
> + vsetvli zero, t0, e16, m2, ta, ma
> + vmax.vx v2, v2, zero
> + vsetvli zero, t0, e8, m1, ta, ma
> + vnclipu.wi v0, v2, 0
> + vsetivli zero, 4, e8, mf2, ta, ma
> + vsse32.v v0, (a0), a1
> + ret
> +endfunc
> diff --git a/libavcodec/vc1dsp.c b/libavcodec/vc1dsp.c
> index 62c8eb21fa..2caa3c6863 100644
> --- a/libavcodec/vc1dsp.c
> +++ b/libavcodec/vc1dsp.c
> @@ -1039,6 +1039,8 @@ av_cold void ff_vc1dsp_init(VC1DSPContext *dsp)
> ff_vc1dsp_init_arm(dsp);
> #elif ARCH_PPC
> ff_vc1dsp_init_ppc(dsp);
> +#elif ARCH_RISCV
> + ff_vc1dsp_init_riscv(dsp);
> #elif ARCH_X86
> ff_vc1dsp_init_x86(dsp);
> #elif ARCH_MIPS
> diff --git a/libavcodec/vc1dsp.h b/libavcodec/vc1dsp.h
> index 7ed1776ca7..e3b90d2b62 100644
> --- a/libavcodec/vc1dsp.h
> +++ b/libavcodec/vc1dsp.h
> @@ -89,6 +89,7 @@ void ff_vc1dsp_init(VC1DSPContext* c);
> void ff_vc1dsp_init_aarch64(VC1DSPContext* dsp);
> void ff_vc1dsp_init_arm(VC1DSPContext* dsp);
> void ff_vc1dsp_init_ppc(VC1DSPContext *c);
> +void ff_vc1dsp_init_riscv(VC1DSPContext *c);
> void ff_vc1dsp_init_x86(VC1DSPContext* dsp);
> void ff_vc1dsp_init_mips(VC1DSPContext* dsp);
> void ff_vc1dsp_init_loongarch(VC1DSPContext* dsp);
--
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