When trying to write an instruction set analysis tool for disassembled code (https://superuser.com/a/832440/384221) I have found opcode MOVABS which was not included in my opcode source database (Shirk's
gas.vim file) and I am not sure in which architecture it has been introduced.
According to What is the meaning of movabs in gas/x86 AT&T syntax? and other sources it seems that the instruction has been introduced before 64-bit architectures. But was it with i686 or earlier?