[PATCH] D103180: [InstSimplify] Add constant fold for extractelement + splat for scalable vectors

[Caroline via Phabricator via llvm-commits]

CarolineConcatto added a comment.

Hi @foad,
I don't know if I understood correct your suggestion.
I did not change any line. 
I  have tried some combinations of IF removals, but they all broke some tests



================
Comment at: llvm/lib/IR/ConstantFold.cpp:916-917
         return CAZ->getElementValue(CIdx->getZExtValue());
+      if (Constant *SplatVal = Val->getSplatValue())
+        return SplatVal;
     }
----------------
foad wrote:
> You should be able to remove the two lines above handling the CAZ case, because your new code will handle it.
a


================
Comment at: llvm/lib/IR/ConstantFold.cpp:916-917
         return CAZ->getElementValue(CIdx->getZExtValue());
+      if (Constant *SplatVal = Val->getSplatValue())
+        return SplatVal;
     }
----------------
CarolineConcatto wrote:
> foad wrote:
> > You should be able to remove the two lines above handling the CAZ case, because your new code will handle it.
> a
Hi @foad 
I believe we should keep these 2 tests:
!CIdx->uge(ValSVTy->getMinNumElements())
because it limits the index to be lower than the minimum width of the scalable vector.

and it should be only for scalable vector because of this 
        return CAZ->getElementValue(CIdx->getZExtValue());
transformation. 
If we change to be vector type  many other  tests fail. For instance this one:
 CodeGen/AMDGPU/amdgpu-codegenprepare-idiv.ll
Transforms/LoopVectorize/X86/gather_scatter.ll


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D103180/new/

https://reviews.llvm.org/D103180