xlvalues.c

C标准库源代码

/* values used by math functions -- IEEE 754 long version */
#include "wctype.h"
#include "xmath.h"
_STD_BEGIN

#if _DLONG	/* long double has unique representation */
		/* macros */
#define NBITS	64
 #if _D0
  #define INIT(w0, w1)		{0, 0, 0, w1, w0}
  #define INIT3(w0, w1, wn)	{wn, 0, 0, w1, w0}
 #else
  #define INIT(w0, w1)		{w0, w1, 0, 0, 0}
  #define INIT3(w0, w1, wn)	{w0, w1, 0, 0, wn}
 #endif
		/* static data */
_CRTIMP2 const _Dconst _LDenorm = {INIT3(0, 0, 1)};
_CRTIMP2 const _Dconst _LEps = {INIT(_LBIAS - NBITS - 1, 0x8000)};
 #if _LONG_DOUBLE_HAS_HIDDEN_BIT
_CRTIMP2 const _Dconst _LInf = {INIT(_LMAX, 0)};
_CRTIMP2 const _Dconst _LNan = {INIT(_LSIGN | _LMAX, 0x8000)};
_CRTIMP2 const _Dconst _LSnan = {INIT(_LSIGN | _LMAX, 0)};
 #else
_CRTIMP2 const _Dconst _LInf = {INIT(_LMAX, 0x8000)};
_CRTIMP2 const _Dconst _LNan = {INIT(_LSIGN | _LMAX, 0xc000)};
_CRTIMP2 const _Dconst _LSnan = {INIT(_LSIGN | _LMAX, 0x8000)};
 #endif
_CRTIMP2 const _Dconst _LRteps = {INIT(_LBIAS - NBITS / 2, 0x8000)};
_CRTIMP2 const long double _LXbig = (NBITS + 1) * 347L / 1000;

 #if defined(__CENTERLINE__)
  #define _DYNAMIC_INIT_CONST(x) \
	(x._L = *(long double *)(void *)(x._W))
long double _centerline_long_double_dynamic_init =
_DYNAMIC_INIT_CONST(_LEps),
_DYNAMIC_INIT_CONST(_LInf),
_DYNAMIC_INIT_CONST(_LNan),
_DYNAMIC_INIT_CONST(_LRteps);
 #endif
#else	/* long double same representation as double */
		/* macros */
 #define NBITS	(48 + _DOFF)
 #if _D0
  #define INIT(w0)		{0, 0, 0, w0}
  #define INIT2(w0, w1)	{w1, 0, 0, w0}
 #else
  #define INIT(w0)		{w0, 0, 0, 0}
  #define INIT2(w0, w1)	{w0, 0, 0, w1}
 #endif
		/* static data */
_CRTIMP2 const _Dconst _LDenorm = {INIT2(0, 1)};
_CRTIMP2 const _Dconst _LEps = {INIT((_DBIAS - NBITS - 1) << _DOFF)};
_CRTIMP2 const _Dconst _LInf = {INIT(_DMAX << _DOFF)};
_CRTIMP2 const _Dconst _LNan = {INIT(_DSIGN | (_DMAX << _DOFF)
	| (1 << _DOFF - 1))};
_CRTIMP2 const _Dconst _LRteps = {INIT((_DBIAS - NBITS / 2) << _DOFF)};
_CRTIMP2 const _Dconst _LSnan = {INIT(_DSIGN | (_DMAX << _DOFF))};
_CRTIMP2 const long double _LXbig = (NBITS + 1) * 347L / 1000;

 #if defined(__CENTERLINE__)
  #define _DYNAMIC_INIT_CONST(x) \
	(x._D = *(long double *)(void *)(x._W))
long double _centerline_long_double_dynamic_inits =
_DYNAMIC_INIT_CONST(_LEps),
_DYNAMIC_INIT_CONST(_LInf),
_DYNAMIC_INIT_CONST(_LNan),
_DYNAMIC_INIT_CONST(_LRteps);
 #endif
#endif
_STD_END

/*
 * Copyright (c) 1994 by P.J. Plauger.  ALL RIGHTS RESERVED. 
 * Consult your license regarding permissions and restrictions.
 */

/*
941029 pjp: added _STD machinery
950222 pjp: added signaling NaN, denorm minimum for C++
950506 pjp: corrected _LDenorm spelling
951005 pjp: added _DLONG logic
951115 pjp: corrected _LXbig type
 */