count_bits

count_bits :: (int x) -> int {...}
count_bits :: (uint x) -> int {...}

pipeline VisibilityCount {
  pass "Main" {
    compute "Main" [64, 1, 1] {
    // Count visible objects in bitmask
    uint visibilityMask = loadVisibilityMask(tileId);
    int visibleCount = count_bits(visibilityMask);

    // Allocate space for visible objects
    int startIndex = atomic_add(totalVisible[0], visibleCount);

    // Process visible objects
    processVisible(tileId, startIndex, visibilityMask);
    }
  }
}

// Count active flags
int activeCount = count_bits(flagBitmask);

// Count lanes with condition true
uint ballot = waveBallot(condition);
int trueCount = count_bits(ballot);

// Count non-zero elements in packed data
int elementCount = count_bits(occupancyMask);

// Count differing bits between two values
int difference = count_bits(a ^ b);

// Count bits before position for exclusive prefix
uint mask = (1u << position) - 1u;
int prefixCount = count_bits(value & mask);

bitCount(x)

countbits(x)

popcount(x)