[llvm] Update the base and index value for masked gather (PR #130920)

[Matt Arsenault via llvm-commits]

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@@ -4905,6 +4905,11 @@ void SelectionDAGBuilder::visitMaskedScatter(const CallInst &I) {
     Scale = DAG.getTargetConstant(1, sdl, TLI.getPointerTy(DAG.getDataLayout()));
   }
 
+  if (!UniformBase) {
+    TLI.updateBaseAndIndex(Ptr, Base, Index, getCurSDLoc(), getValue(Ptr), DAG,
+                           I.getParent());
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arsenm wrote:

The DAG builder should avoid interpreting the incoming IR in target specific ways 

https://github.com/llvm/llvm-project/pull/130920