checks in the loop. size := len(x.limbs) xLimbs := x.limbs[:size] for i := size - 1; i >= 0; i-- { if xLimbs[i] != 0 { return i*_W + bitLen(xLimbs[i]) } } return 0 } // bitLen is a version of bits.Len that only leaks the bit length of n, but not // its value. bits.Len and bits.LeadingZeros use a lookup table for the // low-order bits on some architectures. func bitLen(n uint) int { len := 0 // We assume, here and elsewhere, that comparison to zero is constant time // with respect to different non-zero...