windows-nt/Source/XPSP1/NT/base/crts/crtw32/stdcpp64/xdtest.c
2020-09-26 16:20:57 +08:00

29 lines
650 B
C

/* _Dtest function -- IEEE 754 version */
#include "wctype.h"
#include "xmath.h"
_STD_BEGIN
_CRTIMP2 short _Dtest(double *px)
{ /* categorize *px */
unsigned short *ps = (unsigned short *)px;
if ((ps[_D0] & _DMASK) == _DMAX << _DOFF)
return ((ps[_D0] & _DFRAC) != 0 || ps[_D1] != 0
|| ps[_D2] != 0 || ps[_D3] != 0 ? NAN : INF);
else if ((ps[_D0] & ~_DSIGN) != 0 || ps[_D1] != 0
|| ps[_D2] != 0 || ps[_D3] != 0)
return (FINITE);
else
return (0);
}
_STD_END
/*
* Copyright (c) 1994 by P.J. Plauger. ALL RIGHTS RESERVED.
* Consult your license regarding permissions and restrictions.
*/
/*
941029 pjp: added _STD machinery
*/