[vlc-devel] [PATCH 2/3] deinterlace: x86: add external asm emms function

[Rémi Denis-Courmont]

Le torstaina 20. lokakuuta 2016, 0.53.16 EEST Janne Grunau a écrit :
> ---
>  modules/video_filter/Makefile.am                   |  4 +++
>  modules/video_filter/deinterlace/common.h          |  4 +++
>  .../video_filter/deinterlace/deinterlace_x86.asm   | 34
> ++++++++++++++++++++++ 3 files changed, 42 insertions(+)
>  create mode 100644 modules/video_filter/deinterlace/deinterlace_x86.asm
> 
> diff --git a/modules/video_filter/Makefile.am
> b/modules/video_filter/Makefile.am index 5d5fdaf..92c5bc3 100644
> --- a/modules/video_filter/Makefile.am
> +++ b/modules/video_filter/Makefile.am
> @@ -120,6 +120,10 @@ libdeinterlace_plugin_la_SOURCES = \
>  	video_filter/deinterlace/algo_ivtc.c video_filter/deinterlace/algo_ivtc.h
>  # inline ASM doesn't build with -O0
>  libdeinterlace_plugin_la_CFLAGS = $(AM_CFLAGS) -O2
> +if HAVE_YASM
> +libdeinterlace_plugin_la_CFLAGS += -DHAVE_YASM
> +libdeinterlace_plugin_la_SOURCES +=
> video_filter/deinterlace/deinterlace_x86.asm +endif

I dislike adding a source language conditionally to a target, because GNU/
automake generally just sucks at dealing with such.

>  if HAVE_NEON
>  libdeinterlace_plugin_la_SOURCES += video_filter/deinterlace/merge_arm.S
>  libdeinterlace_plugin_la_CFLAGS += -DCAN_COMPILE_ARM
> diff --git a/modules/video_filter/deinterlace/common.h
> b/modules/video_filter/deinterlace/common.h index dcd7e63..afce82b 100644
> --- a/modules/video_filter/deinterlace/common.h
> +++ b/modules/video_filter/deinterlace/common.h
> @@ -35,4 +35,8 @@
>  #define FFMIN(a,b)      __MIN(a,b)
>  #define FFMIN3(a,b,c)   FFMIN(FFMIN(a,b),c)
> 
> +#if HAVE_YASM
> +void vlcpriv_emms_ext_asm(void);
> +#endif
> +
>  #endif
> diff --git a/modules/video_filter/deinterlace/deinterlace_x86.asm
> b/modules/video_filter/deinterlace/deinterlace_x86.asm new file mode 100644
> index 0000000..60ce829
> --- /dev/null
> +++ b/modules/video_filter/deinterlace/deinterlace_x86.asm
> @@ -0,0 +1,34 @@
> +;**************************************************************************
> *** +;* x86-optimized functions for deinterlace filter
> +;**************************************************************************
> *** +;* Cpyright (C) 2016- VLC authors and VideoLAN
> +;* $Id: 1e2cf65f9467664726cfed16aa792342339946b1 $
> +;*
> +;* Authors: Janne Grunau <janne-vlc at jannau.net>
> +;*
> +;* This file is part of vlc.
> +;*
> +;* This program 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.
> +;*
> +;* This program 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 this program; if not, write to the Free Software Foundation,
> +;* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
> +;*************************************************************************
> ***** +
> +%include "x86util.asm"
> +
> +SECTION_RODATA
> +
> +SECTION .text
> +
> +cglobal emms_ext_asm, 0,0,0
> +        emms
> +        RET

I must first say that I am in no way an expert in x86 ISA and ABI.

But I don´t really see what this function does. It has no input and no output.

-- 
Rémi Denis-Courmont
Nonsponsored VLC developer
http://www.remlab.net/CV.pdf