diff options
Diffstat (limited to 'contrib/pg_trgm/trgm_gist.c')
| -rw-r--r-- | contrib/pg_trgm/trgm_gist.c | 39 |
1 files changed, 24 insertions, 15 deletions
diff --git a/contrib/pg_trgm/trgm_gist.c b/contrib/pg_trgm/trgm_gist.c index 9f1c20cf04..e7c21a435b 100644 --- a/contrib/pg_trgm/trgm_gist.c +++ b/contrib/pg_trgm/trgm_gist.c @@ -36,16 +36,25 @@ Datum gtrgm_picksplit(PG_FUNCTION_ARGS); #define GETENTRY(vec,pos) ((TRGM *) DatumGetPointer((vec)->vector[(pos)].key)) -#define SUMBIT(val) ( \ - GETBITBYTE(val,0) + \ - GETBITBYTE(val,1) + \ - GETBITBYTE(val,2) + \ - GETBITBYTE(val,3) + \ - GETBITBYTE(val,4) + \ - GETBITBYTE(val,5) + \ - GETBITBYTE(val,6) + \ - GETBITBYTE(val,7) \ -) +/* Number of one-bits in an unsigned byte */ +static const uint8 number_of_ones[256] = { + 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, + 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, + 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, + 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, + 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, + 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, + 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, + 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, + 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, + 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 +}; Datum @@ -298,8 +307,7 @@ sizebitvec(BITVECP sign) i; LOOPBYTE( - size += SUMBIT(*(char *) sign); - sign = (BITVECP) (((char *) sign) + 1); + size += number_of_ones[(unsigned char) sign[i]]; ); return size; } @@ -308,11 +316,12 @@ static int hemdistsign(BITVECP a, BITVECP b) { int i, + diff, dist = 0; - LOOPBIT( - if (GETBIT(a, i) != GETBIT(b, i)) - dist++; + LOOPBYTE( + diff = (unsigned char) (a[i] ^ b[i]); + dist += number_of_ones[diff]; ); return dist; } |