[FFmpeg-devel] [PATCH 3/3] riscv: add float vector-scalar multiplication

[Lynne]

Sep 3, 2022, 21:01 by remi at remlab.net:

> From: Rémi Denis-Courmont <remi at remlab.net>
>
> This is based on existing code from the VLC git tree, though the size
> and scalar arguments are swapped.
> ---
>  libavutil/float_dsp.c            |  2 ++
>  libavutil/float_dsp.h            |  1 +
>  libavutil/riscv/Makefile         |  4 ++-
>  libavutil/riscv/float_dsp_init.c | 42 ++++++++++++++++++++++
>  libavutil/riscv/float_dsp_rvv.S  | 60 ++++++++++++++++++++++++++++++++
>  5 files changed, 108 insertions(+), 1 deletion(-)
>  create mode 100644 libavutil/riscv/float_dsp_init.c
>  create mode 100644 libavutil/riscv/float_dsp_rvv.S
>
> diff --git a/libavutil/float_dsp.c b/libavutil/float_dsp.c
> index 8676c8b0f8..742dd679d2 100644
> --- a/libavutil/float_dsp.c
> +++ b/libavutil/float_dsp.c
> @@ -156,6 +156,8 @@ av_cold AVFloatDSPContext *avpriv_float_dsp_alloc(int bit_exact)
>  ff_float_dsp_init_arm(fdsp);
>  #elif ARCH_PPC
>  ff_float_dsp_init_ppc(fdsp, bit_exact);
> +#elif ARCH_RISCV
> +    ff_float_dsp_init_riscv(fdsp);
>  #elif ARCH_X86
>  ff_float_dsp_init_x86(fdsp);
>  #elif ARCH_MIPS
> diff --git a/libavutil/float_dsp.h b/libavutil/float_dsp.h
> index 9c664592bd..7cad9fc622 100644
> --- a/libavutil/float_dsp.h
> +++ b/libavutil/float_dsp.h
> @@ -205,6 +205,7 @@ float avpriv_scalarproduct_float_c(const float *v1, const float *v2, int len);
>  void ff_float_dsp_init_aarch64(AVFloatDSPContext *fdsp);
>  void ff_float_dsp_init_arm(AVFloatDSPContext *fdsp);
>  void ff_float_dsp_init_ppc(AVFloatDSPContext *fdsp, int strict);
> +void ff_float_dsp_init_riscv(AVFloatDSPContext *fdsp);
>  void ff_float_dsp_init_x86(AVFloatDSPContext *fdsp);
>  void ff_float_dsp_init_mips(AVFloatDSPContext *fdsp);
>  
> diff --git a/libavutil/riscv/Makefile b/libavutil/riscv/Makefile
> index 1f818043dc..6bf8243e8d 100644
> --- a/libavutil/riscv/Makefile
> +++ b/libavutil/riscv/Makefile
> @@ -1 +1,3 @@
> -OBJS += riscv/cpu.o
> +OBJS += riscv/cpu.o \
> +        riscv/float_dsp_init.o \
> +        riscv/float_dsp_rvv.o
> diff --git a/libavutil/riscv/float_dsp_init.c b/libavutil/riscv/float_dsp_init.c
> new file mode 100644
> index 0000000000..9a5b981917
> --- /dev/null
> +++ b/libavutil/riscv/float_dsp_init.c
> @@ -0,0 +1,42 @@
> +/*
> + * 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/float_dsp.h"
> +
> +void ff_vector_fmul_scalar_rvv(float *dst, const float *src, float mul,
> +                                int len);
> +
> +void ff_vector_dmul_scalar_rvv(double *dst, const double *src, double mul,
> +                                int len);
> +
> +av_cold void ff_float_dsp_init_riscv(AVFloatDSPContext *fdsp)
> +{
> +    int flags = av_get_cpu_flags();
> +
> +    if (flags & AV_CPU_FLAG_ZVE32F) {
> +        fdsp->vector_fmul_scalar = ff_vector_fmul_scalar_rvv;
> +
> +        if (flags & AV_CPU_FLAG_ZVE64D) {
> +            fdsp->vector_dmul_scalar = ff_vector_dmul_scalar_rvv;H
> +        }
>

Style.


> +    }
> +}
> diff --git a/libavutil/riscv/float_dsp_rvv.S b/libavutil/riscv/float_dsp_rvv.S
> new file mode 100644
> index 0000000000..54ea1d9d6d
> --- /dev/null
> +++ b/libavutil/riscv/float_dsp_rvv.S
> @@ -0,0 +1,60 @@
> +/*
> + * 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 "config.h"
> +#include "asm.h"
> +
> +        .option  arch, +v
> +
> +func ff_vector_fmul_scalar_rvv
> +#if !defined (__riscv_float_abi_soft)
> +        srli     a2, a2, 2
> +#else
> +        fmv.w.x  fa0, a2
> +        srli     a2, a3, 2
> +#endif
>

Can't this be handled by a macro, like it's done by arm64 and x86?