masks

[Uno]

This is excerpted from Plauger:

/* values used by <float.h> macros -- IEEE 754 version */
#include <float.h>

/* macros */
#define DFRAC (49+_DOFF)
#define DMAXE ((1U<<(15-_DOFF))-1)
#define FFRAC (17+_FOFF)
#define FMAXE ((1U<<(15-_FOFF))-1)
#define LFRAC (49+_LOFF)
#define LMAXE 0x7fff
#define LOG2 0.30103
#if _D0 != 0 /* low to high words */
#define DINIT(w0, wx) wx, wx, wx, w0
#define FINIT(w0, wx) wx, w0
#define LINIT(w0, w1, wx) wx, wx, wx, w1, w0
#else /* high to low words */
#define DINIT(w0, wx) w0, wx, wx, wx
#define FINIT(w0, wx) w0, wx
#define LINIT(w0, w1, wx) w0, w1, wx, wx, wx
#endif
/* static data */
_Dvals _Dbl = {
(int)((DFRAC-1)*LOG2), /* DBL_DIG */
(int)DFRAC, /* DBL_MANT_DIG */
(int)((DMAXE-_DBIAS-1)*LOG2), /* DBL_MAX_10_EXP */
(int)(DMAXE-_DBIAS-1), /* DBL_MAX_EXP */
(int)(-_DBIAS*LOG2), /* DBL_MIN_10_EXP */
(int)(1-_DBIAS), /* DBL_MIN_EXP */
{DINIT(_DBIAS-DFRAC+2<<_DOFF, 0)}, /* DBL_EPSILON */
{DINIT((DMAXE<<_DOFF)-1, ~0)}, /* DBL_MAX */
{DINIT(1<<_DOFF, 0)}, /* DBL_MIN */
};
_Dvals _Flt = {
(int)((FFRAC-1)*LOG2), /* FLT_DIG */
(int)FFRAC, /* FLT_MANT_DIG */
(int)((FMAXE-_FBIAS-1)*LOG2), /* FLT_MAX_10_EXP */
(int)(FMAXE-_FBIAS-1), /* FLT_MAX_EXP */
(int)(-_FBIAS*LOG2), /* FLT_MIN_10_EXP */
(int)(1-_FBIAS), /* FLT_MIN_EXP */
{FINIT(_FBIAS-FFRAC+2<<_FOFF, 0)}, /* FLT_EPSILON */
{FINIT((FMAXE<<_FOFF)-1, ~0)}, /* FLT_MAX */
{FINIT(1<<_FOFF, 0)}, /* FLT_MIN */
};
#if _DLONG
_Dvals _Ldbl = {
(int)((LFRAC-1)*LOG2), /* LDBL_DIG */
(int)LFRAC, /* LDBL_MANT_DIG */
(int)((LMAXE-_LBIAS-1)*LOG2), /* LDBL_MAX_10_EXP */
(int)(LMAXE-_LBIAS-1), /* LDBL_MAX_EXP */
(int)(-_LBIAS*LOG2), /* LDBL_MIN_10_EXP */
(int)(1-_LBIAS), /* LDBL_MIN_EXP */
{LINIT(_LBIAS-LFRAC+2, 0x8000, 0)}, /* LDBL_EPSILON */
{LINIT(LMAXE-1, ~0, ~0)}, /* LDBL_MAX */
{LINIT(1, 0x8000, 0)}, /* LDBL_MIN */
};
#else
_Dvals _Ldbl = {
(int)(DFRAC*LOG2), /* LDBL_DIG */
(int)DFRAC, /* LDBL_MANT_DIG */
(int)((DMAXE-_DBIAS-1)*LOG2), /* LDBL_MAX_10_EXP */
(int)(DMAXE-_DBIAS-1), /* LDBL_MAX_EXP */
(int)(-_DBIAS*LOG2), /* LDBL_MIN_10_EXP */
(int)(1-_DBIAS), /* LDBL_MIN_EXP */
{DINIT(_DBIAS-DFRAC+2<<_DOFF, 0)}, /* LDBL_EPSILON */
{DINIT((DMAXE<<_DOFF)-1, ~0)}, /* LDBL_MAX */
{DINIT(1<<_DOFF, 0)}, /* LDBL_MIN */
};
#endif

I can't read through the masks here.

 

[Nick Keighley]

This is excerpted from Plauger:

/* values used by <float.h> macros -- IEEE 754 version */
#include <float.h>

                /* macros */
#define DFRAC   (49+_DOFF)
#define DMAXE   ((1U<<(15-_DOFF))-1)
#define FFRAC   (17+_FOFF)
#define FMAXE   ((1U<<(15-_FOFF))-1)
#define LFRAC   (49+_LOFF)
#define LMAXE   0x7fff
#define LOG2    0.30103
#if _D0 != 0    /* low to high words */
#define DINIT(w0, wx)   wx, wx, wx, w0
#define FINIT(w0, wx)   wx, w0
#define LINIT(w0, w1, wx)       wx, wx, wx, w1, w0
#else   /* high to low words */
#define DINIT(w0, wx)   w0, wx, wx, wx
#define FINIT(w0, wx)   w0, wx
#define LINIT(w0, w1, wx)       w0, w1, wx, wx, wx
#endif
                /* static data */
_Dvals _Dbl = {
        (int)((DFRAC-1)*LOG2),          /* DBL_DIG */
        (int)DFRAC,                             /* DBL_MANT_DIG */
        (int)((DMAXE-_DBIAS-1)*LOG2),   /* DBL_MAX_10_EXP */
        (int)(DMAXE-_DBIAS-1),          /* DBL_MAX_EXP */
        (int)(-_DBIAS*LOG2),    /* DBL_MIN_10_EXP */
        (int)(1-_DBIAS),                /* DBL_MIN_EXP */
        {DINIT(_DBIAS-DFRAC+2<<_DOFF, 0)},        /* DBL_EPSILON */
        {DINIT((DMAXE<<_DOFF)-1, ~0)},    /* DBL_MAX */
        {DINIT(1<<_DOFF, 0)},             /* DBL_MIN */
        };

I can't read through the masks here.

what?

 

[Nick]

I can't read through the masks here.

You've got them on upside down and the eyeholes aren't lining up.