Ideally, like this: fs rep gs fs ; Note: extraneous prefix mov eax, [fs:ebx] Some of disassemblers may put them as raw bytes (db 0x63, 0xf3, 0x65, 0x6

Ideally, like this: fs rep gs fs ; Note: extraneous prefix mov eax, [fs:ebx] Some of disassemblers may put them as raw bytes (db 0x63, 0xf3, 0x65, 0x64). > Note that code can jump past some of the prefixes. The C library on Linux does this to bypass prefixes What's the use case for this? I wouldn't split the prefix from the instruction and would rather use label+1 where it's absolutely required.