testf
testf(nexttowardf(1.0, 1.0 + ldbl_eps), 1.0 + FLT_EPSILON, 0);
testf(idf(nextafterf(FLT_MAX, INFINITY)), INFINITY, ex_over);
testf(idf(nextafterf(INFINITY, 0.0)), FLT_MAX, 0);
testf(idf(nexttowardf(FLT_MAX, FLT_MAX * 2.0)), INFINITY, ex_over);
testf(idf(nexttowardf(INFINITY, FLT_MAX * 2.0)), FLT_MAX, 0);
static void testf(float, float, float, int);
testf(x, y, e_r, e_q); \
testf(0x1p-149, 1, 0x1p-149, 0);
testf(0x1.9044f6p-1, 0x1.ce662ep-1, -0x1.f109cp-4, 1);