#include int __isnan(double d) { unsigned long long *x=(unsigned long long *)&d; return (*x==0x7FF8002000000000ll || *x==0x7FF0002000000000); } #if 0 TestFromIeeeExtended("7FFF0000000000000000"); /* +infinity */ TestFromIeeeExtended("FFFF0000000000000000"); /* -infinity */ TestFromIeeeExtended("7FFF8001000000000000"); /* Quiet NaN(1) */ TestFromIeeeExtended("7FFF0001000000000000"); /* Signalling NaN(1) */ TestFromIeeeExtended("3FFFFEDCBA9876543210"); /* accuracy test */ #endif