You can get a fast equivalent to his zero-padding method on recent-ish x86 and ARM SVE. The x86 assembly would look like (untested): compare: ;; lhs in eax,

You can get a fast equivalent to his zero-padding method on recent-ish x86 and ARM SVE. The x86 assembly would look like (untested): compare: ;; lhs in eax, rhs in ebx mov ecx, 0b11111011111101111 pdep eax, eax, ecx pdep ebx, ebx, ecx sub eax, ebx test eax, 0b10000010000001000 mov eax, 0 setnz al ret