Bit processing is always SIMD. A 64-bit register being processed 64-bits at a time is, from a mental and programmers perspective, a 64-wide SIMD computer over

Bit processing is always SIMD. A 64-bit register being processed 64-bits at a time is, from a mental and programmers perspective, a 64-wide SIMD computer over 1-bit AND, OR, and NOT instructions. If you aren't using SIMD / parallel programming concepts while thinking about 64-parallel bits (or even in this case, parallel processing of 8-bit bytes or 7-bits of ASCII), then you are making life much harder for yourself. ------- I believe in the 90s, some people called 32-bit parallelism as SIMD Within A Register (SWAR). Some guy wrote 3DES encryption with 64-bit AND/OR/NOTs and progressed bit-by-bit (but in parallel), achieving absurdly efficient encryption back in the day. And of course, Chess Programmers with all their 64-bit boards for their 8x8 game constantly think in terms of SIMD inside of 64-bits. ------- Once you learn to think in SIMD, you can extend these concepts out to 128-bits (SSE), 256-bits (AVX) or 512-bit (AVX512) or beyond (GPU 1024-bits and greater).