[FFmpeg-devel] [PATCH] Add support for "omp simd" pragma.

[Martin Storsjö]

On Wed, 13 Jan 2021, Reimar Döffinger wrote:

>> If building with MSVC tools, yes you're right that armasm.exe/armasm64.exe takes a different syntax. But the gas-preprocessor tool (which is picked up automatically by our configure, one just needs to make sure it's available) handles expanding all the macros and rewriting directives into the armasm form, and feeding it to the armasm tools. Works fine and have done so for years. There's even a wiki page which tries to explain how to do it (although it's probably outdated in some aspects), see https://trac.ffmpeg.org/wiki/CompilationGuide/WinRT.
>> 
>
> I went with the instructions in doc/platform.texi and that did not work at all,
> It even tried to use cl.exe to compile the assembler files!

What did you end up trying/doing in this case? That sounds rather broken 
to me.

The main issue just is having gas-preprocessor available (but since you 
need a posix make, like from msys2, it should be pretty easy to have a 
perl installation for gas-preprocessor there) - but if it isn't found, 
configure really should be erroring out and not silently using cl as 
assembler...

My own setups for fate are a bit special as they're cross compiled from 
linux (with msvc wrapped in wine), but it should essentially just be 
"./configure --arch=arm64 --target-os=win32 --toolchain=msvc 
--enable-cross-compile", assuming you have MSVC targeting arm64 in $PATH.

// Martin