7 ms·

Thanks for measuring. From your github source: /* anyone have a big-endian machine at hand to test this? */ #if __BYTE_ORDER == ORDER_LITTLE_ENDIA

by acqq 11y ago

Thanks for measuring. From your github source: /* anyone have a big-endian machine at hand to test this? */ #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ #define MULT 0x8040201008040201ULL #else #define MULT 0x0102040810204080ULL #endif Even without the machine I believe that such a big endian implementation can't work. Hint: you can try it on the little endian machine too, the resulting bits must be appropriate, and I believe they wouldn't. That's the beauty of the magic constants, their construction isn't so easy as it appears to be.

cnvogel 11y ago
You are right, the carry bits will clobber the neighboring bytes, I think.
- acqq 11y ago
  > the carry bits will clobber Actually, not the carry bits, the "content" bits. The 8-bit content must appear on more places there for the magic to work.