[PATCH] D62739: AMDGPU: Always emit amdgpu-flat-work-group-size

Mon Jun 3 06:55:22 PDT 2019

arsenm marked an inline comment as done.
arsenm added inline comments.

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Comment at: lib/CodeGen/TargetInfo.cpp:7885
+    // By default, restrict the maximum size to 256.
+    F->addFnAttr("amdgpu-flat-work-group-size", "128,256");
   }
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yaxunl wrote:
> arsenm wrote:
> > b-sumner wrote:
> > > Theoretically, shouldn't the minimum be 1?
> > That's what I thought, but the backend is defaulting to 2 * wave size now
> I don't get it. This attribute indicates the possible workgroup size range this kernel may be run with, right? It only depends on how user execute the kernel. How is it related to backend defaults?
The backend currently assumes 128,256 by default as the bounds. I want to make this a frontend decision, and make the backend assumption the most conservative default

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  https://reviews.llvm.org/D62739/new/

https://reviews.llvm.org/D62739