diff --git a/llvm/lib/Target/AMDGPU/AMDGPUPreLegalizerCombiner.cpp b/llvm/lib/Target/AMDGPU/AMDGPUPreLegalizerCombiner.cpp
--- a/llvm/lib/Target/AMDGPU/AMDGPUPreLegalizerCombiner.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUPreLegalizerCombiner.cpp
@@ -126,7 +126,6 @@
          LLT::scalar(64));
   const LLT S32 = LLT::scalar(32);
 
-  B.setMBB(*MI.getParent());
   B.setInstrAndDebugLoc(MI);
 
   auto Unmerge = B.buildUnmerge(S32, Src);