diff options
| -rw-r--r-- | src/util/bitset.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/util/bitset.h b/src/util/bitset.h index 4fc4dbb6f3e..cf9e59a01cf 100644 --- a/src/util/bitset.h +++ b/src/util/bitset.h @@ -281,6 +281,20 @@ __bitclear_clear_range(BITSET_WORD *r, unsigned start, unsigned end) __bitclear_clear_range(x, b, e) static inline unsigned +__bitset_extract(const BITSET_WORD *r, unsigned start, unsigned count) +{ + unsigned shift = start % BITSET_WORDBITS; + unsigned lower = r[BITSET_BITWORD(start)] >> shift; + unsigned upper = shift ? r[BITSET_BITWORD(start) + 1] << (32 - shift) : 0; + unsigned total = lower | upper; + + return count != 32 ? total & ((1u << count) - 1u) : total; +} + +#define BITSET_EXTRACT(x, s, c) \ + __bitset_extract(x, s, c) + +static inline unsigned __bitset_prefix_sum(const BITSET_WORD *x, unsigned b, unsigned n) { unsigned prefix = 0; |