INSERT_WORDS
INSERT_WORDS(scale1, (0x3ff + half_expt) << 20, 0);
INSERT_WORDS(scale2, (0x3ff + half_expt) << 20, 0);
INSERT_WORDS(d, hi, (uint32_t)asuint64(d))
INSERT_WORDS(d, asuint64(d)>>32, lo)
INSERT_WORDS(scale, (uint32_t)(0x3ff + k/2) << 20, 0);
INSERT_WORDS(z, ix0 + ((uint32_t)m << 20), ix1);