I'm looking at table 1-12 in "AMD64 Architecture Programmer’s Manual Volume 3: General-Purpose and System Instructions" revision 3.21 (Picture attached). It mentions DH and BH in the base register column for ModRM SIB adressing. Does anyone know if that means that there's actually a way to do ModRM SIB addressing with byte registers?
P.S.: Could a mod please move this to an appropriate place? There seems any number of graphics related forums, but no CPU forums, but surely that must just be me going blind! :-)