Index: include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
===================================================================
--- include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
+++ include/llvm/CodeGen/GlobalISel/RegisterBankInfo.h
@@ -193,7 +193,7 @@
     unsigned Cost = 0;
 
     /// Mapping of all the operands.
-    const ValueMapping *OperandsMapping;
+    const ValueMapping *OperandsMapping = nullptr;
 
     /// Number of operands.
     unsigned NumOperands = 0;
@@ -217,8 +217,6 @@
                        unsigned NumOperands)
         : ID(ID), Cost(Cost), OperandsMapping(OperandsMapping),
           NumOperands(NumOperands) {
-      assert(getID() != InvalidMappingID &&
-             "Use the default constructor for invalid mapping");
     }
 
     /// Default constructor.
Index: lib/CodeGen/GlobalISel/RegisterBankInfo.cpp
===================================================================
--- lib/CodeGen/GlobalISel/RegisterBankInfo.cpp
+++ lib/CodeGen/GlobalISel/RegisterBankInfo.cpp
@@ -392,11 +392,8 @@
   ++NumInstructionMappingsCreated;
 
   auto &InstrMapping = MapOfInstructionMappings[Hash];
-  if (IsInvalid)
-    InstrMapping = llvm::make_unique<InstructionMapping>();
-  else
-    InstrMapping = llvm::make_unique<InstructionMapping>(
-        ID, Cost, OperandsMapping, NumOperands);
+  InstrMapping = llvm::make_unique<InstructionMapping>(
+      ID, Cost, OperandsMapping, NumOperands);
   return *InstrMapping;
 }