docs: static void normalizedBoundaries(long d64, DiyFp m_minus, DiyFp m_plus) {
          DiyFp v = asDiyFp(d64);
          boolean significand_is_zero = (v.f() == kHiddenBit);
          m_plus.setF((v.f() << 1) + 1);
          m_plus.setE(v.e() - 1);
          m_plus.normalize();
          if (significand_is_zero && v.e() != kDenormalExponent) {
              // The boundary is closer. Think of v = 1000e10 and v- = 9999e9.
              // Then the boundary (== (v - v-)/2) is not just at a distance of 1e9 but
              // at a distance of 1e8.
              // The only exception is for the smallest normal: the largest denormal is
              // at the same distance as its successor.
              // Note: denormals have the same exponent as the smallest normals.
              m_minus.setF((v.f() << 2) - 1);
              m_minus.setE(v.e() - 2);
          } else {
              m_minus.setF((v.f() << 1) - 1);
              m_minus.setE(v.e() - 1);
          }
          m_minus.setF(m_minus.f() << (m_minus.e() - m_plus.e()));
          m_minus.setE(m_plus.e());
      }