sub_ddmmss
sub_ddmmss (n1, n0, n1, n0, d1, d0);
sub_ddmmss (m1, m0, m1, m0, d1, d0);
sub_ddmmss (n1, n0, n1, n0, m1, m0);
#define __FP_FRAC_SUB_2 sub_ddmmss
#define __FP_FRAC_DEC_2(xh, xl, yh, yl) sub_ddmmss(xh, xl, xh, xl, yh, yl)
#if !defined(sub_ddmmss)
sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl); \
sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
sub_ddmmss(n1, n0, n1, n0, d1, d0);
sub_ddmmss(n1, n0, n1, n0, 0, d0);
sub_ddmmss(n1, n0, r, n2, n1, n0);