I am reading some material which quotes Intel's vol.2 SDM x86 manual about opcodes and machine-code encoding of assembly instructions, but I cannot understand what things like cw, cd, /2, cp, or /3 mean following the opcode byte.
E8 cw CALL rel16 Call near, relative, displacement relative to next instruction E8 cd CALL rel32 Call near, relative, displacement relative to next instruction FF /2 CALL r/m16 Call near, absolute indirect, address given in r/m16 FF /2 CALL r/m32 Call near, absolute indirect, address given in r/m32 9A cd CALL ptr16:16 Call far, absolute, address given in operand 9A cp CALL ptr16:32 Call far, absolute, address given in operand FF /3 CALL m16:16 Call far, absolute indirect, address given in m16:16 FF /3 CALL m16:32 Call far, absolute indirect, address given in m16:32
Can someone explain what that's about? Does Intel's own manual have a section on how to read their notation? (Spoiler alert: yes, there's an intro chapter in vol.2.)
My favorite source is Intel itself: Intel® 64 and IA-32 Architectures Software Developer Manuals. And unlike versions past, all of the volumes are now nicely wrapped up in a single (3044 page) PDF.
It looks like the section that will help you most is 3.1.1.1 in Chapter 3 of Volume 2 (page 432 of the latest PDF as of the date I am writing this).