msb function

int msb(
  1. int bb
)

Index of the most-significant set bit. bb must be non-zero.

Implementation

int msb(int bb) {
  bb |= bb >>> 1;
  bb |= bb >>> 2;
  bb |= bb >>> 4;
  bb |= bb >>> 8;
  bb |= bb >>> 16;
  bb |= bb >>> 32;
  return _index64[((bb * _debruijn64) >>> 58) & 63];
}