Index: lib/Target/AMDGPU/SIInstrInfo.cpp
===================================================================
--- lib/Target/AMDGPU/SIInstrInfo.cpp
+++ lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -1416,6 +1416,16 @@
     }
   }
 
+  // Make sure we aren't losing exec uses in the td files. This mostly requires
+  // being careful when using let Uses to try to add other use registers.
+  if (!isBuiltinOpcode(Opcode) && !isSALU(Opcode) && !isSMRD(Opcode)) {
+    const MachineOperand *Exec = MI->findRegisterUseOperand(AMDGPU::EXEC);
+    if (!Exec || !Exec->isImplicit()) {
+      ErrInfo = "VALU instruction does not implicitly read exec mask";
+      return false;
+    }
+  }
+
   return true;
 }