From Libcpu

The x86 front-end is work in progress. We're targeting the 8086 instruction set now and leaving i386 and x86-64 for later. The front-end is currently being maintained by Pekka.

Documentation

• Pekka's blog post on libcpu x86 front-end
• Intel Manuals
• x86 instruction listings

ToDo

Here are some things that are known to be missing from the x86 decoder (ask Pekka for details):

• SIB byte decoding
• Operand size override prefix decoding
• x87 instruction decoding
• REX prefix decoding