Method _bitCount

runtime/JavaScript/src/antlr4/misc/BitSet.js:113–122

(l)

    }

    static _bitCount(l) {
        // see https://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
        let count = 0;
        l = l - ((l >> 1) & 0x55555555);
        l = (l & 0x33333333) + ((l >> 2) & 0x33333333);
        l = (l + (l >> 4)) & 0x0f0f0f0f;
        l = l + (l >> 8);
        l = l + (l >> 16);
        return count + l & 0x3f;
    }
}