[PATCH] D83715: AMDGPU/GlobalISel: Use clamp modifier for uaddsat/usubsat

Tue Jul 14 05:31:15 PDT 2020

arsenm added a comment.

In D83715#2150014 <https://reviews.llvm.org/D83715#2150014>, @arsenm wrote:

> In D83715#2149633 <https://reviews.llvm.org/D83715#2149633>, @foad wrote:
>
> > > There's an annoying asymmetry where we have signed saturating for
> > >  packed operations, but not for scalar 16-bit.
> >
> > My Vega Instruction Set Architecture Reference Guide says:
> >  "V_ADD_I16
> >  D.i16 = S0.i16 + S1.i16.
> >  Supports saturation (signed 16-bit integer domain)."
>
>
> Seems missing from the gfx8 and 10 manuals? I'm guessing it's really there though

I did find a note that it was added in gfx9, still not sure about 10

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83715/new/

https://reviews.llvm.org/D83715