Record does not have a field named `SoftFail'

In attempting to write a backend I copied the Sparc backend and have been busy modifying it for my target processor.

I have a single instruction (early work in progress) and I am getting the following error from tablegen:

6> Building XXXXGenRegisterInfo.inc…
6> Building XXXXGenInstrInfo.inc…
6> Building XXXXGenDisassemblerTables.inc…
6> Included from D:/llvm/lib/Target/XXXX/XXXX.td:25:
6> D:/llvm/lib/Target/XXXX\XXXXInstrInfo.td:23:1: error: Record INSTR' does not have a field named SoftFail’!
6>
6> def INSTR : MyInstrClass;
6> ^
6>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.CppCommon.targets(170,5): error MSB6006: “cmd.exe” exited with code 1.

I have searched the directory that all of my code is in and I cannot find the string SoftFail in any file. I also don’t see a reference to it in the “Writing an LLVM Backend” page.

How would I deal with this error? If SoftFail is a required field, where is the documentation on it?