AT&T syntax is best syntax. Linux, GCC, LLVM, etc. all use it. [name redacted] writes it in a style that's more verbose than it needs to be. It's probably a good call since this is an educational blog post. Like there's some nuance to when you need things like q on statements `movq %rdi,8(%rsp)`. For example, this is fine: `mov %rdi,8(%rsp)` but you need it if you move an immediate to memory, e.g. `movq $123,8(%rsp)`. I like to avoid them because mnemonics like `orb` don't appear to the untrained eye as the `or` instruction! The GNU-style suffixes can also appear multiple times within an instruction name in various combinations, e.g. pclmullqlqdq vs. pclmulhqhqdq.