[llvm] [SLP][REVEC] Disable strided load if the source is vector instruction. (PR #99462)

[Han-Kuan Chen via llvm-commits]

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@@ -4582,8 +4582,12 @@ BoUpSLP::LoadsState BoUpSLP::canVectorizeLoads(
     return LoadsState::Gather;
   }
 
+  // If ScalarTy is a FixedVectorType (when REVEC is enabled), it is hard for
+  // being strided load.
+  bool IsSourceScalarInstruction = !isa<FixedVectorType>(VL[0]->getType());
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HanKuanChen wrote:

Why do we use `VectorType` here? SLP does not accept `ScalableVectorType`.

https://github.com/llvm/llvm-project/pull/99462