#ifndef SIGNAL_SUPPRESS #include #endif double dnan = 1.0/0.0 - 1.0/0.0; double x = 1.0; void leave () { exit (0); } main () { #if ! defined (__vax__) && ! defined (_CRAY) /* Move this line earlier, for architectures (like alpha) that issue SIGFPE on the first comparisons. */ #ifndef SIGNAL_SUPPRESS /* Some machines catches a SIGFPE when a NaN is compared. Let this test succeed o such machines. */ signal (SIGFPE, leave); #endif /* NaN is an IEEE unordered operand. All these test should be false. */ if (dnan == dnan) abort (); if (dnan != x) x = 1.0; else abort (); if (dnan < x) abort (); if (dnan > x) abort (); if (dnan <= x) abort (); if (dnan >= x) abort (); if (dnan == x) abort (); #endif exit (0); }