diff options
| -rw-r--r-- | src/include/common/hashfn_unstable.h | 26 |
1 files changed, 3 insertions, 23 deletions
diff --git a/src/include/common/hashfn_unstable.h b/src/include/common/hashfn_unstable.h index e07c0226c1f..8818a0d360b 100644 --- a/src/include/common/hashfn_unstable.h +++ b/src/include/common/hashfn_unstable.h @@ -14,8 +14,6 @@ #ifndef HASHFN_UNSTABLE_H #define HASHFN_UNSTABLE_H -#include "port/pg_bitutils.h" -#include "port/pg_bswap.h" /* * fasthash is a modification of code taken from @@ -262,26 +260,13 @@ fasthash_accum_cstring_aligned(fasthash_state *hs, const char *str) /* * For every chunk of input, check for zero bytes before mixing into the - * hash. The chunk with zeros must contain the NUL terminator. We arrange - * so that zero_byte_low tells us not only that a zero exists, but also - * where it is, so we can hash the remainder of the string. - * - * The haszero64 calculation will set bits corresponding to the lowest - * byte where a zero exists, so that suffices for little-endian machines. - * For big-endian machines, we would need bits set for the highest zero - * byte in the chunk, since the trailing junk past the terminator could - * contain additional zeros. haszero64 does not give us that, so we - * byteswap the chunk first. + * hash. The chunk with zeros must contain the NUL terminator. */ for (;;) { uint64 chunk = *(uint64 *) str; -#ifdef WORDS_BIGENDIAN - zero_byte_low = haszero64(pg_bswap64(chunk)); -#else zero_byte_low = haszero64(chunk); -#endif if (zero_byte_low) break; @@ -290,13 +275,8 @@ fasthash_accum_cstring_aligned(fasthash_state *hs, const char *str) str += FH_SIZEOF_ACCUM; } - /* - * The byte corresponding to the NUL will be 0x80, so the rightmost bit - * position will be in the range 7, 15, ..., 63. Turn this into byte - * position by dividing by 8. - */ - remainder = pg_rightmost_one_pos64(zero_byte_low) / BITS_PER_BYTE; - fasthash_accum(hs, str, remainder); + /* mix in remaining bytes */ + remainder = fasthash_accum_cstring_unaligned(hs, str); str += remainder; return str - start; |