[PATCH] D83216: [Intrinsic] Add sshl.sat/ushl.sat, saturated shift intrinsics.

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-sshlsat.mir:17
+    ; GFX6: [[TRUNC1:%[0-9]+]]:_(s7) = G_TRUNC [[COPY1]](s32)
+    ; GFX6: [[SSHLSAT:%[0-9]+]]:_(s7) = G_SSHLSAT [[TRUNC]], [[TRUNC1]]
+    ; GFX6: [[ANYEXT:%[0-9]+]]:_(s32) = G_ANYEXT [[SSHLSAT]](s7)
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ebevhan wrote:
> arsenm wrote:
> > These all failed to legalize.
> > 
> > You need something like this in AMDGPULegalizerInfo
> > 
> > ```
> >   getActionDefinitionsBuilder({G_SSHLSAT, G_USHLSAT})
> >     .scalarize(0)
> >     .clampScalar(0, S32)
> >     .lower();
> > 
> > ```
> > 
> > to actually trigger any of the legalization code
> Okay, I thought something was off.
> 
> Does this mean that any target that wants these legalized with the default legalization needs to specify this explicitly?
Yes,  nearly everything is opt-in in GlobalISel


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D83216/new/

https://reviews.llvm.org/D83216