From: Akim Demaille Date: Mon, 16 Nov 2020 06:22:35 +0000 (+0100) Subject: bitset: use ffs where possible in array implementation X-Git-Tag: v1.0~3500 X-Git-Url: https://gitweb.git.savannah.gnu.org/gitweb/?a=commitdiff_plain;h=abc5606bb1b591cf03d51029e4d5d532d16b717e;p=gnulib.git bitset: use ffs where possible in array implementation * lib/bitset/array.c (abitset_small_list): Use BITSET_FOR_EACH_BIT. --- diff --git a/ChangeLog b/ChangeLog index 657768f3b5..8ee603345f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2020-11-17 Akim Demaille + + bitset: use ffs where possible in array implementation + * lib/bitset/array.c (abitset_small_list): Use BITSET_FOR_EACH_BIT. + 2020-11-17 Bruno Haible posixcheck: Don't enable GNULIB_POSIXCHECK in C++ mode. diff --git a/lib/bitset/array.c b/lib/bitset/array.c index 6c5f7ed34f..3f8bcca87d 100644 --- a/lib/bitset/array.c +++ b/lib/bitset/array.c @@ -62,38 +62,25 @@ abitset_small_list (bitset src, bitset_bindex *list, word >>= bitno; - /* If num is 1, we could speed things up with a binary search - of the word of interest. */ - - bitset_bindex count; + bitset_bindex count = 0; + /* Is there enough room to avoid checking in each iteration? */ if (num >= BITSET_WORD_BITS) { - for (count = 0; word; bitno++) - { - if (word & 1) - list[count++] = bitno; - word >>= 1; - } + BITSET_FOR_EACH_BIT (pos, word) + list[count++] = bitno + pos; + *next = bitno + BITSET_WORD_BITS; + return count; } else - { - for (count = 0; word; bitno++) - { - if (word & 1) - { - list[count++] = bitno; - if (count >= num) - { - bitno++; - break; - } - } - word >>= 1; - } - } - - *next = bitno; - return count; + BITSET_FOR_EACH_BIT (pos, word) + { + list[count++] = bitno + pos; + if (count >= num) + { + *next = bitno + pos + 1; + return count; + } + } } @@ -205,9 +192,6 @@ abitset_list (bitset src, bitset_bindex *list, if (windex >= size) return 0; - /* If num is 1, we could speed things up with a binary search - of the current word. */ - bitoff = windex * BITSET_WORD_BITS; } else