diff --git a/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp b/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
--- a/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
@@ -2696,7 +2696,7 @@
     RC = MRI.getRegClass(Reg);
   else
     RC = getPhysRegClass(Reg);
-  return isSGPRClass(RC);
+  return RC ? isSGPRClass(RC) : false;
 }
 
 const TargetRegisterClass *