[llvm] [LoongArch] Fix broadcast load with extension. (PR #155960)

[via llvm-commits]

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@@ -2516,11 +2516,14 @@ static SDValue lowerBUILD_VECTORAsBroadCastLoad(BuildVectorSDNode *BVOp,
   }
 
   // make sure that this load is valid and only has one user.
-  if (!IdentitySrc || !BVOp->isOnlyUserOf(IdentitySrc.getNode()))
+  if (!IsIdeneity || !IdentitySrc || !BVOp->isOnlyUserOf(IdentitySrc.getNode()))
     return SDValue();
 
-  if (IsIdeneity) {
-    auto *LN = cast<LoadSDNode>(IdentitySrc);
+  auto *LN = cast<LoadSDNode>(IdentitySrc);
+  auto ExtType = LN->getExtensionType();
+
+  if ((ExtType == ISD::EXTLOAD || ExtType == ISD::NON_EXTLOAD) &&
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tangaac wrote:

The error occurs in a load with extension.
I think it's better to keep this extension type judgement.

https://github.com/llvm/llvm-project/pull/155960