64-BIT SWAR vs. 128-BIT SIMD SSE SWAR https://github.com/jart/cosmopolitan/blob/b3838173ecbb67fae548008ae9a24ce7289fed1c/libc/str/strlen-pure.c#L23-L45 SIMD https://github.com/jart/cosmopolitan/blob/b3838173ecbb67fae548008ae9a24ce7289fed1c/libc/nexgen32e/strlen.S#L21-L51 strlen_sse 1 l: 6𝑐 2𝑛𝑠 m: 36𝑐 12𝑛𝑠 strlen_swar 1 l: 2𝑐 1𝑛𝑠 m: 28𝑐 9𝑛𝑠 strlen_sse 2 l: 6𝑐 2𝑛𝑠 m: 35𝑐 11𝑛𝑠 strlen_swar 2 l: 3𝑐 1𝑛𝑠 m: 32𝑐 10𝑛𝑠 strlen_sse 3 l: 6𝑐 2𝑛𝑠 m: 39𝑐 13𝑛𝑠 strlen_swar 3 l: 3𝑐 1𝑛𝑠 m: 31𝑐 10𝑛𝑠 strlen_sse 4 l: 6𝑐 2𝑛𝑠 m: 36𝑐 12𝑛𝑠 strlen_swar 4 l: 7𝑐 2𝑛𝑠 m: 38𝑐 12𝑛𝑠 strlen_sse 7 l: 6𝑐 2𝑛𝑠 m: 36𝑐 12𝑛𝑠 strlen_swar 7 l: 7𝑐 2𝑛𝑠 m: 38𝑐 12𝑛𝑠 strlen_sse 8 l: 6𝑐 2𝑛𝑠 m: 32𝑐 10𝑛𝑠 strlen_swar 8 l: 6𝑐 2𝑛𝑠 m: 37𝑐 12𝑛𝑠 strlen_sse 9 l: 7𝑐 2𝑛𝑠 m: 36𝑐 12𝑛𝑠 strlen_swar 9 l: 7𝑐 2𝑛𝑠 m: 37𝑐 12𝑛𝑠 strlen_sse 11 l: 6𝑐 2𝑛𝑠 m: 38𝑐 12𝑛𝑠 strlen_swar 11 l: 11𝑐 4𝑛𝑠 m: 49𝑐 16𝑛𝑠 strlen_sse 13 l: 7𝑐 2𝑛𝑠 m: 36𝑐 12𝑛𝑠 strlen_swar 13 l: 9𝑐 3𝑛𝑠 m: 37𝑐 12𝑛𝑠 strlen_sse 16 l: 6𝑐 2𝑛𝑠 m: 36𝑐 12𝑛𝑠 strlen_swar 16 l: 8𝑐 3𝑛𝑠 m: 37𝑐 12𝑛𝑠 strlen_sse 17 l: 7𝑐 2𝑛𝑠 m: 40𝑐 13𝑛𝑠 strlen_swar 17 l: 11𝑐 4𝑛𝑠 m: 51𝑐 16𝑛𝑠 strlen_sse 34 l: 10𝑐 3𝑛𝑠 m: 46𝑐 15𝑛𝑠 strlen_swar 34 l: 8𝑐 3𝑛𝑠 m: 41𝑐 13𝑛𝑠 strlen_sse 68 l: 13𝑐 4𝑛𝑠 m: 55𝑐 18𝑛𝑠 strlen_swar 68 l: 15𝑐 5𝑛𝑠 m: 45𝑐 15𝑛𝑠 strlen_sse 256 l: 29𝑐 9𝑛𝑠 m: 68𝑐 22𝑛𝑠 strlen_swar 256 l: 42𝑐 14𝑛𝑠 m: 88𝑐 28𝑛𝑠 strlen_sse 512 l: 51𝑐 16𝑛𝑠 m: 104𝑐 34𝑛𝑠 strlen_swar 512 l: 81𝑐 26𝑛𝑠 m: 125𝑐 40𝑛𝑠 strlen_sse 2048 l: 205𝑐 66𝑛𝑠 m: 246𝑐 79𝑛𝑠 strlen_swar 2048 l: 334𝑐 108𝑛𝑠 m: 374𝑐 121𝑛𝑠