G4LogConsts Namespace Reference

Data Structures
union	ieee754

Functions
G4double	get_log_px (const G4double x)
G4double	get_log_qx (const G4double x)
uint64_t	dp2uint64 (G4double x)
G4double	uint642dp (uint64_t ll)
G4float	uint322sp (G4int x)
uint32_t	sp2uint32 (G4float x)
G4double	getMantExponent (const G4double x, G4double &fe)
	Like frexp but vectorising and the exponent is a double. More...
G4float	getMantExponentf (const G4float x, G4float &fe)
	Like frexp but vectorising and the exponent is a float. More...
G4float	get_log_poly (const G4float x)

Variables
const G4double	LOG_UPPER_LIMIT = 1e307
const G4double	LOG_LOWER_LIMIT = 0
const G4double	SQRTH = 0.70710678118654752440
const G4float	MAXNUMF = 3.4028234663852885981170418348451692544e38f
const G4float	LOGF_UPPER_LIMIT = MAXNUMF
const G4float	LOGF_LOWER_LIMIT = 0
const G4float	PX1logf = 7.0376836292E-2f
const G4float	PX2logf = -1.1514610310E-1f
const G4float	PX3logf = 1.1676998740E-1f
const G4float	PX4logf = -1.2420140846E-1f
const G4float	PX5logf = 1.4249322787E-1f
const G4float	PX6logf = -1.6668057665E-1f
const G4float	PX7logf = 2.0000714765E-1f
const G4float	PX8logf = -2.4999993993E-1f
const G4float	PX9logf = 3.3333331174E-1f
const G4float	SQRTHF = 0.707106781186547524f

Function Documentation

uint64_t G4LogConsts::dp2uint64 ( G4double  x )

inline

Definition at line 147 of file G4Log.hh.

References G4LogConsts::ieee754::d, G4LogConsts::ieee754::ll, and test::x.

Referenced by getMantExponent().

  {
    ieee754 tmp;
    tmp.d=x;
    return tmp.ll;
  }

G4float G4LogConsts::get_log_poly ( const G4float  x )

inline

Definition at line 282 of file G4Log.hh.

References PX1logf, PX2logf, PX3logf, PX4logf, PX5logf, PX6logf, PX7logf, PX8logf, PX9logf, and test::x.

Referenced by G4Logf().

  {
        G4float y = x*PX1logf;
        y += PX2logf;
        y *= x;
        y += PX3logf;
        y *= x;
        y += PX4logf;
        y *= x;
        y += PX5logf;
        y *= x;
        y += PX6logf;
        y *= x;
        y += PX7logf;
        y *= x;
        y += PX8logf;
        y *= x;
        y += PX9logf;
        return y;
  }

G4double G4LogConsts::get_log_px ( const G4double  x )

inline

Definition at line 100 of file G4Log.hh.

References test::x.

Referenced by G4Log().

  {
        const G4double PX1log = 1.01875663804580931796E-4;
        const G4double PX2log = 4.97494994976747001425E-1;
        const G4double PX3log = 4.70579119878881725854E0;
        const G4double PX4log = 1.44989225341610930846E1;
        const G4double PX5log = 1.79368678507819816313E1;
        const G4double PX6log = 7.70838733755885391666E0;

        G4double px = PX1log;
        px *= x;
        px += PX2log;
        px *= x;
        px += PX3log;
        px *= x;
        px += PX4log;
        px *= x;
        px += PX5log;
        px *= x;
        px += PX6log;
        return px;
  }

G4double G4LogConsts::get_log_qx ( const G4double  x )

inline

Definition at line 123 of file G4Log.hh.

References test::x.

Referenced by G4Log().

  {
        const G4double QX1log = 1.12873587189167450590E1;
        const G4double QX2log = 4.52279145837532221105E1;
        const G4double QX3log = 8.29875266912776603211E1;
        const G4double QX4log = 7.11544750618563894466E1;
        const G4double QX5log = 2.31251620126765340583E1;

        G4double qx = x;
        qx += QX1log;
        qx *=x;
        qx += QX2log;
        qx *=x;
        qx += QX3log;
        qx *=x;
        qx += QX4log;
        qx *=x;
        qx += QX5log;
        return qx;
  }

G4double G4LogConsts::getMantExponent ( const G4double  x, G4double &  fe  )

inline

Like frexp but vectorising and the exponent is a double.

Definition at line 186 of file G4Log.hh.

References dp2uint64(), n, and uint642dp().

Referenced by G4Log().

  {
    uint64_t n = dp2uint64(x);

    // Shift to the right up to the beginning of the exponent.
    // Then with a mask, cut off the sign bit
    uint64_t le = (n >> 52);

    // chop the head of the number: an int contains more than 11 bits (32)
    int32_t e = le; // This is important since sums on uint64_t do not vectorise
    fe = e-1023 ;

    // This puts to 11 zeroes the exponent
    n &=0x800FFFFFFFFFFFFFULL;
    // build a mask which is 0.5, i.e. an exponent equal to 1022
    // which means *2, see the above +1.
    const uint64_t p05 = 0x3FE0000000000000ULL; //dp2uint64(0.5);
    n |= p05;

    return uint642dp(n);
  }

G4float G4LogConsts::getMantExponentf ( const G4float  x, G4float &  fe  )

inline

Like frexp but vectorising and the exponent is a float.

Definition at line 210 of file G4Log.hh.

References n, sp2uint32(), and uint322sp().

Referenced by G4Logf().

  {
    uint32_t n = sp2uint32(x);
    int32_t e = (n >> 23)-127;
    fe = e;

    // fractional part
    const uint32_t p05f = 0x3f000000; // //sp2uint32(0.5);
    n &= 0x807fffff;// ~0x7f800000;
    n |= p05f;

    return uint322sp(n);
  }

uint32_t G4LogConsts::sp2uint32 ( G4float  x )

inline

Definition at line 177 of file G4Log.hh.

References G4LogConsts::ieee754::f, G4LogConsts::ieee754::i, and test::x.

Referenced by getMantExponentf().

  {
    ieee754 tmp;
    tmp.f[0]=x;
    return tmp.i[0];
  }

G4float G4LogConsts::uint322sp ( G4int  x )

inline

Definition at line 167 of file G4Log.hh.

References G4LogConsts::ieee754::f, G4LogConsts::ieee754::i, and test::x.

Referenced by getMantExponentf().

  {
    ieee754 tmp;
    tmp.i[0]=x;
    return tmp.f[0];
  }

G4double G4LogConsts::uint642dp ( uint64_t  ll )

inline

Definition at line 157 of file G4Log.hh.

References G4LogConsts::ieee754::d, and G4LogConsts::ieee754::ll.

Referenced by getMantExponent().

  {
    ieee754 tmp;
    tmp.ll=ll;
    return tmp.d;
  }

Variable Documentation

const G4double G4LogConsts::LOG_LOWER_LIMIT = 0

Definition at line 77 of file G4Log.hh.

Referenced by G4Log().

const G4double G4LogConsts::LOG_UPPER_LIMIT = 1e307

Definition at line 76 of file G4Log.hh.

Referenced by G4Log().

const G4float G4LogConsts::LOGF_LOWER_LIMIT = 0

Definition at line 270 of file G4Log.hh.

Referenced by G4Logf().

const G4float G4LogConsts::LOGF_UPPER_LIMIT = MAXNUMF

Definition at line 269 of file G4Log.hh.

Referenced by G4Logf().

const G4float G4LogConsts::MAXNUMF = 3.4028234663852885981170418348451692544e38f

Definition at line 80 of file G4Log.hh.

const G4float G4LogConsts::PX1logf = 7.0376836292E-2f

Definition at line 272 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX2logf = -1.1514610310E-1f

Definition at line 273 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX3logf = 1.1676998740E-1f

Definition at line 274 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX4logf = -1.2420140846E-1f

Definition at line 275 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX5logf = 1.4249322787E-1f

Definition at line 276 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX6logf = -1.6668057665E-1f

Definition at line 277 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX7logf = 2.0000714765E-1f

Definition at line 278 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX8logf = -2.4999993993E-1f

Definition at line 279 of file G4Log.hh.

Referenced by get_log_poly().

const G4float G4LogConsts::PX9logf = 3.3333331174E-1f

Definition at line 280 of file G4Log.hh.

Referenced by get_log_poly().

const G4double G4LogConsts::SQRTH = 0.70710678118654752440

Definition at line 79 of file G4Log.hh.

Referenced by G4Log().

const G4float G4LogConsts::SQRTHF = 0.707106781186547524f

Definition at line 303 of file G4Log.hh.

Referenced by G4Logf().