highbit

来自「Calc Software Package for Number Calc」· 代码 · 共 56 行

NAME
    highbit - index of highest bit in binary representation of integer

SYNOPSIS
    highbit(x)

TYPES
    x		nonzero integer

    return	integer

DESCRIPTION
    If x is a nonzero integer, highbit(x) returns the index of the
    highest bit in the binary representation of abs(x).	 Equivalently,
    highbit(x) = n if 2^n <= abs(x) < 2^(n + 1);  the binary
    representation of x then has n + 1 digits.

EXAMPLE
    ; print highbit(2), highbit(3), highbit(4), highbit(-15), highbit(2^27)
    1 1 2 3 27

LIMITS
    none

LINK LIBRARY
    LEN zhighbit(ZVALUE x);

SEE ALSO
    lowbit, digits

## Copyright (C) 1999  Landon Curt Noll
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL.  You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
##
## @(#) $Revision: 29.3 $
## @(#) $Id: highbit,v 29.3 2006/05/07 07:25:46 chongo Exp $
## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/highbit,v $
##
## Under source code control:	1995/10/03 10:40:02
## File existed as early as:	1995
##
## chongo <was here> /\oo/\	http://www.isthe.com/chongo/
## Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/