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Diffstat (limited to 'mpi/generic/udiv-w-sdiv.c')
| -rw-r--r-- | mpi/generic/udiv-w-sdiv.c | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/mpi/generic/udiv-w-sdiv.c b/mpi/generic/udiv-w-sdiv.c deleted file mode 100644 index 7ffec099..00000000 --- a/mpi/generic/udiv-w-sdiv.c +++ /dev/null @@ -1,135 +0,0 @@ -/* mpihelp_udiv_w_sdiv -- implement udiv_qrnnd on machines with only signed - * division. - * - * Contributed by Peter L. Montgomery. - * - * Copyright (C) 1992, 1994, 1996, 1998 Free Software Foundation, Inc. - * - * This file is part of GnuPG. - * - * GnuPG is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * GnuPG 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 General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA - */ - -#include <config.h> -#include <stdio.h> -#include <stdlib.h> -#include "mpi-internal.h" -#include "longlong.h" - - -#if 0 /* not yet ported to MPI */ - -mpi_limb_t -mpihelp_udiv_w_sdiv( mpi_limp_t *rp, - mpi_limp_t *a1, - mpi_limp_t *a0, - mpi_limp_t *d ) -{ - mp_limb_t q, r; - mp_limb_t c0, c1, b1; - - if ((mpi_limb_signed_t) d >= 0) - { - if (a1 < d - a1 - (a0 >> (BITS_PER_MP_LIMB - 1))) - { - /* dividend, divisor, and quotient are nonnegative */ - sdiv_qrnnd (q, r, a1, a0, d); - } - else - { - /* Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d */ - sub_ddmmss (c1, c0, a1, a0, d >> 1, d << (BITS_PER_MP_LIMB - 1)); - /* Divide (c1*2^32 + c0) by d */ - sdiv_qrnnd (q, r, c1, c0, d); - /* Add 2^31 to quotient */ - q += (mp_limb_t) 1 << (BITS_PER_MP_LIMB - 1); - } - } - else - { - b1 = d >> 1; /* d/2, between 2^30 and 2^31 - 1 */ - c1 = a1 >> 1; /* A/2 */ - c0 = (a1 << (BITS_PER_MP_LIMB - 1)) + (a0 >> 1); - - if (a1 < b1) /* A < 2^32*b1, so A/2 < 2^31*b1 */ - { - sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */ - - r = 2*r + (a0 & 1); /* Remainder from A/(2*b1) */ - if ((d & 1) != 0) - { - if (r >= q) - r = r - q; - else if (q - r <= d) - { - r = r - q + d; - q--; - } - else - { - r = r - q + 2*d; - q -= 2; - } - } - } - else if (c1 < b1) /* So 2^31 <= (A/2)/b1 < 2^32 */ - { - c1 = (b1 - 1) - c1; - c0 = ~c0; /* logical NOT */ - - sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */ - - q = ~q; /* (A/2)/b1 */ - r = (b1 - 1) - r; - - r = 2*r + (a0 & 1); /* A/(2*b1) */ - - if ((d & 1) != 0) - { - if (r >= q) - r = r - q; - else if (q - r <= d) - { - r = r - q + d; - q--; - } - else - { - r = r - q + 2*d; - q -= 2; - } - } - } - else /* Implies c1 = b1 */ - { /* Hence a1 = d - 1 = 2*b1 - 1 */ - if (a0 >= -d) - { - q = -1; - r = a0 + d; - } - else - { - q = -2; - r = a0 + 2*d; - } - } - } - - *rp = r; - return q; -} - -#endif - |