[PATCH] D35267: Pass Divergence Analysis data to selection DAG to drive divergence dependent instruction selection

[Alexander via Phabricator via llvm-commits]

alex-t added inline comments.


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Comment at: lib/Target/AMDGPU/AMDGPUISelLowering.cpp:786
+            RI->getRegClass(AMDGPU::VReg_256RegClassID)->contains(Reg) ||
+            RI->getRegClass(AMDGPU::VReg_512RegClassID)->contains(Reg);
+        }
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rampitec wrote:
> I am afraid that is not true to say that VGPR is necessarily divergent.
That's not true.  Do we have a mean to detect that this is a splat vector?
If not I'd stay with conservative approach that consider all VGPRs divergent.
Alternatively we could add one more target hook to query for special VGPRs that are uniform.


https://reviews.llvm.org/D35267