#include long double dfrom = 1.1L; long double m1; long double m2; unsigned long mant_long; int main() { /* Some targets don't support a conforming long double type. This is common with very small parts which set long double == float. Look to see if the type has at least 32 bits of precision. */ if (LDBL_EPSILON > 0x1p-31L) return 0; m1 = dfrom / 2.0L; m2 = m1 * 4294967296.0L; mant_long = ((unsigned long) m2) & 0xffffffff; if (mant_long == 0x8ccccccc) return 0; else abort(); }