https://issues.dlang.org/show_bug.cgi?id=12971
--- Comment #1 from Orvid King <[email protected]> --- As a bit more information, this is caused by a missing REX prefix, and also applies to OR, XOR, AND, ADD, SUB, and a few other instructions that use op-code 0x80 as their (I know there's a name for the set, but I can't remember it or find it anywhere :( ) I believe it is also limited to the r8, imm8 version of the op-codes. --
