libbox-dev 2.5-3 / usr / include / BoxLib / FPC.H

/*
** (c) 1996-2000 The Regents of the University of California (through
** E.O. Lawrence Berkeley National Laboratory), subject to approval by
** the U.S. Department of Energy.  Your use of this software is under
** license -- the license agreement is attached and included in the
** directory as license.txt or you may contact Berkeley Lab's Technology
** Transfer Department at TTD@lbl.gov.  NOTICE OF U.S. GOVERNMENT RIGHTS.
** The Software was developed under funding from the U.S. Government
** which consequently retains certain rights as follows: the
** U.S. Government has been granted for itself and others acting on its
** behalf a paid-up, nonexclusive, irrevocable, worldwide license in the
** Software to reproduce, prepare derivative works, and perform publicly
** and display publicly.  Beginning five (5) years after the date
** permission to assert copyright is obtained from the U.S. Department of
** Energy, and subject to any subsequent five (5) year renewals, the
** U.S. Government is granted for itself and others acting on its behalf
** a paid-up, nonexclusive, irrevocable, worldwide license in the
** Software to reproduce, prepare derivative works, distribute copies to
** the public, perform publicly and display publicly, and to permit
** others to do so.
*/

#ifndef BL_FPC_H
#define BL_FPC_H

//
// $Id: FPC.H,v 1.6 2001/07/19 16:57:32 lijewski Exp $
//

#include <FabConv.H>

//
//@Man:
//@Memo: A Collection of Floating-Point Constants Supporting FAB I/O
/*@Doc:

  This class is a poor-person's namespace of floating-point constants
  used in support of FAB I/O.  Since we can't assume the existence of
  namespaces, and we don't like global constants, we make them static
  constant data members of this class.
*/

class FPC
{
public:
    //
    //@ManDoc: 4-element array representing "normal" float order: {1,2,3,4}
    //
    static const int normal_float_order[];
    //
    //@ManDoc: 4-element array representing "reverse" float order: {4,3,2,1}
    //
    static const int reverse_float_order[];
    //
    //@ManDoc: Another "reversed" FP order: {2,1,4,3}
    //
    static const int reverse_float_order_2[];
    //
    //@ManDoc: The "normal" double order: {1,2,3,4,5,6,7,8}
    //
    static const int normal_double_order[];
    //
    //@ManDoc: A "reversed" double order: {8,7,6,5,4,3,2,1}
    //
    static const int reverse_double_order[];
    //
    //@ManDoc: Another "reversed" double order: {2,1,4,3,6,5,8,7}
    //
    static const int reverse_double_order_2[];
    //
    //@ManDoc: The Cray float order: {1,2,3,4,5,6,7,8}
    //
    static const int cray_float_order[];

    /*@ManDoc: Array detailing the format of IEEE 32-bit normal order floats.

       In general, here's what the various indices in "format" array means:

          format[0] = number of bits per number
          format[1] = number of bits in exponent
          format[2] = number of bits in mantissa
          format[3] = start bit of sign
          format[4] = start bit of exponent
          format[5] = start bit of mantissa
          format[6] = high order mantissa bit (CRAY needs this)
          format[7] = bias of exponent
    */
    static const long ieee_float[];
    //
    //@ManDoc: Array detailing the format of IEEE 64-bit normal order doubles.
    //
    static const long ieee_double[];
    //
    //@ManDoc: Array detailing the format of Cray floating point.
    //
    static const long cray_float[];

    /*@ManDoc: Returns a constant reference to an IntDescriptor describing
               the native "long" under which BoxLib was compiled.  Each
               BoxLib library will have exactly one of these compiled into it.
    */
    static const IntDescriptor&  NativeLongDescriptor ();

    /*@ManDoc: Returns a constant reference to a RealDescriptor describing
               the native Real under which BoxLib was compiled.  Each BoxLib
               library will have exactly one of these compiled into it.
               Note that "Real" will be one of "float" or "double" depending
               on how the version of BoxLib was built.
    */
    static const RealDescriptor& NativeRealDescriptor ();

    /*@ManDoc: Returns a constant reference to a RealDescriptor detailing
               the Cray FP format.
    */
    static const RealDescriptor& CrayRealDescriptor ();

    /*@ManDoc: Returns a constant reference to a RealDescriptor detailing
               the IEEE 32-bit normal FP format.
    */
    static const RealDescriptor& Ieee32NormalRealDescriptor ();

    /*@ManDoc: Returns a constant reference to a RealDescriptor detailing
               the IEEE 64-bit normal FP format.
    */
    static const RealDescriptor& Ieee64NormalRealDescriptor ();
};

#endif /*BL_FPC_H*/