[llvm-dev] [RFC] RISC-V backend

[Renato Golin via llvm-dev]

On 18 August 2016 at 14:32, Alex Bradbury <asb at asbradbury.org> wrote:
> Good question, I didn't mention buildbots in this RFC as from a quick
> look at http://lab.llvm.org:8011/builders it didn't look like
> early-stage architecture ports tend to have one, and as you say
> check-all should be be enough initially.

They normally don't. But your target won't be tested by any other
buildbot unless it's built by default, which only happens when it's
made official.

So, either you have some local validation (buildbot, weekly build +
check-all, doesn't matter), with your target built in, or you won't
know when your tests regress.


> I'm sure that we (i.e.
> lowRISC CIC) can support an additional buildbot when appropriate. Is
> there any recommendation on minimum specification?

If you have a server which can do some LLVM builds (can be any arch),
then you just create a buildslave and add
-DLLVM_TARGETS_TO_BUILD=RISCV to the CMake options, running check-all.

This doesn't need to be public, but you don't want to find test
failures only when we move your target to official, then it breaks
*all* buildbots, etc.


> At what point do
> you think providing an extra buildbot would become a priority? If any
> additional value can be provided by doing so I'd definitely like to
> have a buildbot before RISC-V becomes an 'official' rather than
> 'experimental' arch.

Official arches should have at least some testing. Many official
arches test on other bots (like BPF and Lanai building on x86_64 bots)
and this could be the case of RISCV.

Of course, more bots / configurations are always welcome, but it will
depend on the target and the community's engagement.

cheers,
--renato