NAME
    hnrmod - compute mod h * 2^n +r

SYNOPSIS
    hnrmod(v, h, n, r)

TYPES
    v           integer
    h           integer
    n           integer
    r           integer

    return      integer

DESCRIPTION
    Compute the value:

        v % (h * 2^n +r)

    where:

        h > 0
        n > 0
        r == -1, 0 or 1

    This builtin in faster than the standard mod in that is makes use
    of shifts and additions when h == 1.  When h > 1, a division by h
    is also needed.

EXAMPLE
    ; print hnrmod(2^177-1, 1, 177, -1), hnrmod(10^40, 17, 51, 1)
    0 33827019788296445

LIMITS
    h > 0
    2^31 > n > 0
    r == -1, 0 or 1

LINK LIBRARY
    void zhnrmod(ZVALUE v, ZVALUE h, ZVALUE zn, ZVALUE zr, ZVALUE *res)

SEE ALSO
    mod

## 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.
## 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
##
## Under source code control:   1997/07/02 07:10:43
## File existed as early as:    1997
##
## chongo <was here> /\oo/\     http://www.isthe.com/chongo/
## Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
