[llvm] [DSE] Add predicated vector length store support for masked store elimination (PR #134175)

[Craig Topper via llvm-commits]

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@@ -269,6 +269,41 @@ static OverwriteResult isMaskedStoreOverwrite(const Instruction *KillingI,
       return OW_Unknown;
     return OW_Complete;
   }
+  if (KillingII->getIntrinsicID() == Intrinsic::vp_store) {
+    // Operands {0        , 1     , 2   , 3 }
+    //          {StoredVal, VecPtr, Mask, VL}
+    // Types.
+    VectorType *KillingTy =
+        cast<VectorType>(KillingII->getArgOperand(0)->getType());
+    VectorType *DeadTy = cast<VectorType>(DeadII->getArgOperand(0)->getType());
+    if (KillingTy->getScalarSizeInBits() != DeadTy->getScalarSizeInBits())
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topperc wrote:

I guess the masked store handling earlier in this function has the same issue?

https://github.com/llvm/llvm-project/pull/134175