offset.h Source File

00001 //
00002 // offset.h
00003 //
00004 // Copyright (C) 1996 Limit Point Systems, Inc.
00005 //
00006 // Author: Curtis Janssen <cljanss@ca.sandia.gov>
00007 // Maintainer: LPS
00008 //
00009 // This file is part of the SC Toolkit.
00010 //
00011 // The SC Toolkit is free software; you can redistribute it and/or modify
00012 // it under the terms of the GNU Library General Public License as published by
00013 // the Free Software Foundation; either version 2, or (at your option)
00014 // any later version.
00015 //
00016 // The SC Toolkit is distributed in the hope that it will be useful,
00017 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00018 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019 // GNU Library General Public License for more details.
00020 //
00021 // You should have received a copy of the GNU Library General Public License
00022 // along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
00023 // the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
00024 //
00025 // The U.S. Government is granted a limited license as per AL 91-7.
00026 //
00027 
00028 #ifndef _math_scmat_offset_h
00029 #define _math_scmat_offset_h
00030 
00031 #ifdef __c_plus_plus
00032 
00033 namespace sc {
00034 
00035 static inline int
00036 i_offset(int i)
00037 {
00038   return ((i*(i+1)) >> 1);
00039 }
00040 
00041 static inline int
00042 ij_offset(int i, int j)
00043 {
00044   return (i>j) ? (((i*(i+1)) >> 1) + j) : (((j*(j+1)) >> 1) + i);
00045 }
00046 
00047 static inline int
00048 igtj_offset(int i, int j)
00049 {
00050   return ((i*(i+1)) >> 1) + j;
00051 }
00052 
00053 }
00054 
00055 #else
00056 
00057 #define i_offset(i) (((i)*((i)+1))>>1)
00058 #define ij_offset(i,j) (((i)>(j))?(i_offset(i)+(j)):(i_offset(j)+(i)))
00059 #define igtj_offset(i,j) (i_offset(i)+(j))
00060 
00061 #endif
00062 
00063 #endif