📄 values.h
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#ifndef BITSPERBYTE/* These values work with any binary representation of integers * where the high-order bit contains the sign. *//* a number used normally for size of a shift *//* @(#)values.h 1.1 11/21/89 ATT ESI */#if gcos#define BITSPERBYTE 9#else#define BITSPERBYTE 8#endif#define BITS(type) (BITSPERBYTE * (int)sizeof(type))/* short, regular and long ints with only the high-order bit turned on */#define HIBITS ((short)(1 << BITS(short) - 1))#define HIBITI (1 << BITS(int) - 1)#define HIBITL (1L << BITS(long) - 1)/* largest short, regular and long int */#define MAXSHORT ((short)~HIBITS)#define MAXINT (~HIBITI)#define MAXLONG (~HIBITL)/* various values that describe the binary floating-point representation * _EXPBASE - the exponent base * DMAXEXP - the maximum exponent of a double (as returned by frexp()) * FMAXEXP - the maximum exponent of a float (as returned by frexp()) * DMINEXP - the minimum exponent of a double (as returned by frexp()) * FMINEXP - the minimum exponent of a float (as returned by frexp()) * MAXDOUBLE - the largest double ((_EXPBASE ** DMAXEXP) * (1 - (_EXPBASE ** -DSIGNIF))) * MAXFLOAT - the largest float ((_EXPBASE ** FMAXEXP) * (1 - (_EXPBASE ** -FSIGNIF))) * MINDOUBLE - the smallest double (_EXPBASE ** (DMINEXP - 1)) * MINFLOAT - the smallest float (_EXPBASE ** (FMINEXP - 1)) * DSIGNIF - the number of significant bits in a double * FSIGNIF - the number of significant bits in a float * DMAXPOWTWO - the largest power of two exactly representable as a double * FMAXPOWTWO - the largest power of two exactly representable as a float * _IEEE - 1 if IEEE standard representation is used * _DEXPLEN - the number of bits for the exponent of a double * _FEXPLEN - the number of bits for the exponent of a float * _HIDDENBIT - 1 if high-significance bit of mantissa is implicit * LN_MAXDOUBLE - the natural log of the largest double -- log(MAXDOUBLE) * LN_MINDOUBLE - the natural log of the smallest double -- log(MINDOUBLE) */#if u3b || u3b5#define MAXDOUBLE 1.79769313486231470e+308#define MAXFLOAT ((float)3.40282346638528860e+38)#define MINDOUBLE 4.94065645841246544e-324#define MINFLOAT ((float)1.40129846432481707e-45)#define _IEEE 1#define _DEXPLEN 11#define _HIDDENBIT 1#define DMINEXP (-(DMAXEXP + DSIGNIF - _HIDDENBIT - 3))#define FMINEXP (-(FMAXEXP + FSIGNIF - _HIDDENBIT - 3))#endif#if pdp11 || vax || iAPX286 || MSDOS#define MAXDOUBLE 1.701411834604692293e+38#define MAXFLOAT ((float)1.701411733192644299e+38)/* The following is kludged because the PDP-11 compilers botch the simple form. The kludge causes the constant to be computed at run-time on the PDP-11, even though it is still "folded" at compile-time on the VAX. */#define MINDOUBLE (0.01 * 2.938735877055718770e-37)#define MINFLOAT ((float)MINDOUBLE)#define _IEEE 0#define _DEXPLEN 8#define _HIDDENBIT 1#define DMINEXP (-DMAXEXP)#define FMINEXP (-FMAXEXP)#endif#if gcos#define MAXDOUBLE 1.7014118346046923171e+38#define MAXFLOAT ((float)1.7014118219281863150e+38)#define MINDOUBLE 2.9387358770557187699e-39#define MINFLOAT ((float)MINDOUBLE)#define _IEEE 0#define _DEXPLEN 8#define _HIDDENBIT 0#define DMINEXP (-(DMAXEXP + 1))#define FMINEXP (-(FMAXEXP + 1))#endif#if u370#define _LENBASE 4#else#define _LENBASE 1#endif#define _EXPBASE (1 << _LENBASE)#define _FEXPLEN 8#define DSIGNIF (BITS(double) - _DEXPLEN + _HIDDENBIT - 1)#define FSIGNIF (BITS(float) - _FEXPLEN + _HIDDENBIT - 1)#define DMAXPOWTWO ((double)(1L << BITS(long) - 2) * \ (1L << DSIGNIF - BITS(long) + 1))#define FMAXPOWTWO ((float)(1L << FSIGNIF - 1))#define DMAXEXP ((1 << _DEXPLEN - 1) - 1 + _IEEE)#define FMAXEXP ((1 << _FEXPLEN - 1) - 1 + _IEEE)#define LN_MAXDOUBLE (M_LN2 * DMAXEXP)#define LN_MINDOUBLE (M_LN2 * (DMINEXP - 1))#define H_PREC (DSIGNIF % 2 ? (1L << DSIGNIF/2) * M_SQRT2 : 1L << DSIGNIF/2)#define X_EPS (1.0/H_PREC)#define X_PLOSS ((double)(long)(M_PI * H_PREC))#define X_TLOSS (M_PI * DMAXPOWTWO)#define M_LN2 0.69314718055994530942#define M_PI 3.14159265358979323846#define M_SQRT2 1.41421356237309504880#define MAXBEXP DMAXEXP /* for backward compatibility */#define MINBEXP DMINEXP /* for backward compatibility */#define MAXPOWTWO DMAXPOWTWO /* for backward compatibility */#endif
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