DBL_FRACLBITS
for (; s > s0 + sigfigs - (DBL_FRACLBITS / 4) - 1 && s > s0; s--) {
for (; s > s0 + sigfigs - ((DBL_FRACLBITS + DBL_FRACMBITS) / 4) - 1
r <<= DBL_FRACLBITS;
exp -= DBL_FRACLBITS;
r <<= DBL_FRACLBITS;
exp -= DBL_FRACLBITS;
x >>= 64 - (DBL_FRACHBITS + DBL_FRACLBITS);
x >>= 64 - (DBL_FRACHBITS + DBL_FRACLBITS);
#define DBL_FRACBITS (DBL_FRACHBITS + DBL_FRACLBITS)
unsigned int dbl_fracl:DBL_FRACLBITS;
unsigned int dbl_fracl:DBL_FRACLBITS;