hypre/struct_ls/general.c
falgout e3181f26b1 Added 64 bit feature using HYPRE_Int (see tracker [issue489] for details).
Changed MPI routines to hypre_MPI routines.
Added hypre_printf, etc. routines.
Added AUTOTEST tests to look for 'int' and 'MPI_' calls.
Added a new approach for the Fortran interface (not implemented everywhere yet).
2010-12-20 19:27:44 +00:00

46 lines
1.2 KiB
C

/*BHEADER**********************************************************************
* Copyright (c) 2008, Lawrence Livermore National Security, LLC.
* Produced at the Lawrence Livermore National Laboratory.
* This file is part of HYPRE. See file COPYRIGHT for details.
*
* HYPRE is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License (as published by the Free
* Software Foundation) version 2.1 dated February 1999.
*
* $Revision$
***********************************************************************EHEADER*/
/******************************************************************************
*
*
*****************************************************************************/
#include "headers.h"
/*--------------------------------------------------------------------------
* hypre_Log2:
* This routine returns the integer, floor(log_2(p)).
* If p <= 0, it returns a -1.
*--------------------------------------------------------------------------*/
HYPRE_Int
hypre_Log2(HYPRE_Int p)
{
HYPRE_Int e;
if (p <= 0)
return -1;
e = 0;
while (p > 1)
{
e += 1;
p /= 2;
}
return e;
}