Derived from the May 2019 version of the Intel® 64 and IA-32 Architectures Software Developer’s Manual. Last updated 2019-05-30. By Félix Cloutier. THIS REFERENCE IS NOT PERFECT. It's been mechanically separated into distinct files by a dumb script. It may be enough to replace the official documentation on your weekend reverse engineering project, but for anything where money is at stake, go get the official and freely available documentation.