>It might be worth noting that strictly speaking this isn't safe to apply to an arbitrary binary. That is 31 c0 and 33 c0 might behave identically when executed

>It might be worth noting that strictly speaking this isn't safe to apply to an arbitrary binary. That is 31 c0 and 33 c0 might behave identically when executed as xor, but they could, for example, also be part of a larger instruction where the swap results in a change in behavior. Technically speaking, you can't apply any transformation to arbitrary binaries, because then the encoding changes and the code can look back at itself. This actually features heavily in a recent Hacker News article https://news.ycombinator.com/item?id=23557998 https://news.ycombinator.com/item?id=23557998 about reverse engineering the Snapchat app, where the code regularly took checksums of itself to frustrate debuggers and take different codepaths if tampering (such as to insert breakpoints) was detected. Assembly is kind of, in a sense, the ultimate homoiconic programming language.