[PATCH] D20297: AMDGPU/SI: Add amdgcn versions of remaining builtins

[Jan Vesely via llvm-commits]

jvesely added a comment.

In http://reviews.llvm.org/D20297#431404, @arsenm wrote:

> In http://reviews.llvm.org/D20297#431388, @jvesely wrote:
>
> > In http://reviews.llvm.org/D20297#431315, @arsenm wrote:
> >
> > > In http://reviews.llvm.org/D20297#431298, @jvesely wrote:
> > >
> > > > In http://reviews.llvm.org/D20297#431268, @arsenm wrote:
> > > >
> > > > > We don't actually want these. We now have the kernarg.segment.ptr intrinsic, so the library should just directly read the offsets from there
> > > >
> > > >
> > > > I assume it points to the beginning of the kernel args.
> > > >  Is the idea to have another intrinsic to read from the end (workdim, global offset), or is it OK to have intrinsics for those?
> > >
> > >
> > > We should fix clover to not read from the end of the arguments (I thought this is what it already did)?
> >
> >
> > some are before the kernel args (global size, local size, ngroups -- this is done by radeonsi/r600 mesa driver). others are after the kernel arguments (work_dim, global-offset -- this is done by clover).
> >  The intention was to move all implicit arguments after the explicit ones, so new implicit arguments can be added without breaking ABI (moving explicit arguments).
>
>
> I think clover should move towards matching the HSA ABI closer. Most of the implicit arguments would then be user SGPR inputs like HSA uses, and the number of implicit args would be reduced.


new implicit arguments were appended to allow newer mesa to work with older llvm (without ifdef hell) any kind of significant abi change would break that (otherwise it'd be in one palce and we'd avoi this problem).
I'm not sure how much of a problem it is and what other (possible) users of clover might want. anyway, it's beyond scope of me trying to make get_global_offset() work. would you be OK if I restricted the changes to r600?


Repository:
  rL LLVM

http://reviews.llvm.org/D20297