diff --git a/llvm/utils/TableGen/CodeGenRegisters.cpp b/llvm/utils/TableGen/CodeGenRegisters.cpp
--- a/llvm/utils/TableGen/CodeGenRegisters.cpp
+++ b/llvm/utils/TableGen/CodeGenRegisters.cpp
@@ -2025,7 +2025,8 @@
       }
     }
     LLVM_DEBUG(dbgs() << "\n");
-    assert(!RegClassUnitSets[RCIdx].empty() && "missing unit set for regclass");
+    assert((!RegClassUnitSets[RCIdx].empty() || !RC.GeneratePressureSet) &&
+           "missing unit set for regclass");
   }
 
   // For each register unit, ensure that we have the list of UnitSets that