Re: [Patch]+[RFC] AMDGCN offloading – use amdgcn-amdhsa vs. amdgcn-unknown-amdhsa

[Andrew Stubbs <ams@codesourcery.com>]

On 20/03/2020 21:08, Tobias Burnus wrote:
> Dear all,
> 
> normally, the target triplet does not play much of a role as
> it is not really exposed to the user. However, for offloading,
> it appears often:
> * In distribution use, offloading support is compiled in, but
>    not enabled by default; one needs to use -foffload=… explicitly.
> * Even with the default build (all offload targets are enabled by
>    default), one still might need to specify the host triplet – if,
>    e.g., NVidia and GCN are both supported — as AMDGCN needs a
>    -march=, i.e. -foffload=<triplet>=-march=...
> 
> Coming to offloading:
> * for Nvidia, everyone uses "nvptx-none"
> * for AMDGCN is was initially "amdgcn-unknown-amdhsa"
> 
> However, when Matthias build it for Debian, he shortened it to
> "amdgcn-amdhsa" – as did Richard for SUSE. Cf
> https://salsa.debian.org/toolchain-team/gcc/-/blob/master/debian/rules2
> andhttps://build.opensuse.org/package/view_file/devel:gcc/gcc10/gcc.spec.in?expand=1 
> 
> 
> This shortening makes it user friendlier and I like it, but
> it now causes that the offloading target is not recognized by
> the testsuite – and I think one also should update the documentation.
> 
> 
> OK – or do you have better/additional suggestions?

The patch looks OK to me, as far as fixing the immediate problem goes.

I hadn't realised this test was so fragile though. :-(

Perhaps it should also recognise the standard names used in the OpenACC 
documentation? In this case "radeon". (I don't recall, off hand, if 
OpenMP uses standard device names.)

Andrew