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diff --git a/mpi/mpi-div.c b/mpi/mpi-div.c
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-/* mpi-div.c - MPI functions
- * Copyright (C) 1998 Free Software Foundation, Inc.
- * Copyright (C) 1994, 1996 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
- *
- * Note: This code is heavily based on the GNU MP Library.
- * Actually it's the same code with only minor changes in the
- * way the data is stored; this is to support the abstraction
- * of an optional secure memory allocation which may be used
- * to avoid revealing of sensitive data due to paging etc.
- * The GNU MP Library itself is published under the LGPL;
- * however I decided to publish this code under the plain GPL.
- */
-
-#include <config.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include "mpi-internal.h"
-#include "longlong.h"
-
-
-
-void
-mpi_fdiv_r( MPI rem, MPI dividend, MPI divisor )
-{
- int divisor_sign = divisor->sign;
- MPI temp_divisor = NULL;
-
- /* We need the original value of the divisor after the remainder has been
- * preliminary calculated. We have to copy it to temporary space if it's
- * the same variable as REM. */
- if( rem == divisor ) {
- temp_divisor = mpi_copy( divisor );
- divisor = temp_divisor;
- }
-
- mpi_tdiv_r( rem, dividend, divisor );
-
- if( ((divisor_sign?1:0) ^ (dividend->sign?1:0)) && rem->nlimbs )
- mpi_add( rem, rem, divisor);
-
- if( temp_divisor )
- mpi_free(temp_divisor);
-}
-
-
-
-/****************
- * Division rounding the quotient towards -infinity.
- * The remainder gets the same sign as the denominator.
- * rem is optional
- */
-
-ulong
-mpi_fdiv_r_ui( MPI rem, MPI dividend, ulong divisor )
-{
- mpi_limb_t rlimb;
-
- rlimb = mpihelp_mod_1( dividend->d, dividend->nlimbs, divisor );
- if( rlimb && dividend->sign )
- rlimb = divisor - rlimb;
-
- if( rem ) {
- rem->d[0] = rlimb;
- rem->nlimbs = rlimb? 1:0;
- }
- return rlimb;
-}
-
-
-void
-mpi_fdiv_q( MPI quot, MPI dividend, MPI divisor )
-{
- MPI tmp = mpi_alloc( mpi_get_nlimbs(quot) );
- mpi_fdiv_qr( quot, tmp, dividend, divisor);
- mpi_free(tmp);
-}
-
-void
-mpi_fdiv_qr( MPI quot, MPI rem, MPI dividend, MPI divisor )
-{
- int divisor_sign = divisor->sign;
- MPI temp_divisor = NULL;
-
- if( quot == divisor || rem == divisor ) {
- temp_divisor = mpi_copy( divisor );
- divisor = temp_divisor;
- }
-
- mpi_tdiv_qr( quot, rem, dividend, divisor );
-
- if( (divisor_sign ^ dividend->sign) && rem->nlimbs ) {
- mpi_sub_ui( quot, quot, 1 );
- mpi_add( rem, rem, divisor);
- }
-
- if( temp_divisor )
- mpi_free(temp_divisor);
-}
-
-
-/* If den == quot, den needs temporary storage.
- * If den == rem, den needs temporary storage.
- * If num == quot, num needs temporary storage.
- * If den has temporary storage, it can be normalized while being copied,
- * i.e no extra storage should be allocated.
- */
-
-void
-mpi_tdiv_r( MPI rem, MPI num, MPI den)
-{
- mpi_tdiv_qr(NULL, rem, num, den );
-}
-
-void
-mpi_tdiv_qr( MPI quot, MPI rem, MPI num, MPI den)
-{
- mpi_ptr_t np, dp;
- mpi_ptr_t qp, rp;
- mpi_size_t nsize = num->nlimbs;
- mpi_size_t dsize = den->nlimbs;
- mpi_size_t qsize, rsize;
- mpi_size_t sign_remainder = num->sign;
- mpi_size_t sign_quotient = num->sign ^ den->sign;
- unsigned normalization_steps;
- mpi_limb_t q_limb;
- mpi_ptr_t marker[5];
- int markidx=0;
-
- /* Ensure space is enough for quotient and remainder.
- * We need space for an extra limb in the remainder, because it's
- * up-shifted (normalized) below. */
- rsize = nsize + 1;
- mpi_resize( rem, rsize);
-
- qsize = rsize - dsize; /* qsize cannot be bigger than this. */
- if( qsize <= 0 ) {
- if( num != rem ) {
- rem->nlimbs = num->nlimbs;
- rem->sign = num->sign;
- MPN_COPY(rem->d, num->d, nsize);
- }
- if( quot ) {
- /* This needs to follow the assignment to rem, in case the
- * numerator and quotient are the same. */
- quot->nlimbs = 0;
- quot->sign = 0;
- }
- return;
- }
-
- if( quot )
- mpi_resize( quot, qsize);
-
- /* Read pointers here, when reallocation is finished. */
- np = num->d;
- dp = den->d;
- rp = rem->d;
-
- /* Optimize division by a single-limb divisor. */
- if( dsize == 1 ) {
- mpi_limb_t rlimb;
- if( quot ) {
- qp = quot->d;
- rlimb = mpihelp_divmod_1( qp, np, nsize, dp[0] );
- qsize -= qp[qsize - 1] == 0;
- quot->nlimbs = qsize;
- quot->sign = sign_quotient;
- }
- else
- rlimb = mpihelp_mod_1( np, nsize, dp[0] );
- rp[0] = rlimb;
- rsize = rlimb != 0?1:0;
- rem->nlimbs = rsize;
- rem->sign = sign_remainder;
- return;
- }
-
-
- if( quot ) {
- qp = quot->d;
- /* Make sure QP and NP point to different objects. Otherwise the
- * numerator would be gradually overwritten by the quotient limbs. */
- if(qp == np) { /* Copy NP object to temporary space. */
- np = marker[markidx++] = mpi_alloc_limb_space(nsize,
- mpi_is_secure(quot));
- MPN_COPY(np, qp, nsize);
- }
- }
- else /* Put quotient at top of remainder. */
- qp = rp + dsize;
-
- count_leading_zeros( normalization_steps, dp[dsize - 1] );
-
- /* Normalize the denominator, i.e. make its most significant bit set by
- * shifting it NORMALIZATION_STEPS bits to the left. Also shift the
- * numerator the same number of steps (to keep the quotient the same!).
- */
- if( normalization_steps ) {
- mpi_ptr_t tp;
- mpi_limb_t nlimb;
-
- /* Shift up the denominator setting the most significant bit of
- * the most significant word. Use temporary storage not to clobber
- * the original contents of the denominator. */
- tp = marker[markidx++] = mpi_alloc_limb_space(dsize,mpi_is_secure(den));
- mpihelp_lshift( tp, dp, dsize, normalization_steps );
- dp = tp;
-
- /* Shift up the numerator, possibly introducing a new most
- * significant word. Move the shifted numerator in the remainder
- * meanwhile. */
- nlimb = mpihelp_lshift(rp, np, nsize, normalization_steps);
- if( nlimb ) {
- rp[nsize] = nlimb;
- rsize = nsize + 1;
- }
- else
- rsize = nsize;
- }
- else {
- /* The denominator is already normalized, as required. Copy it to
- * temporary space if it overlaps with the quotient or remainder. */
- if( dp == rp || (quot && (dp == qp))) {
- mpi_ptr_t tp;
-
- tp = marker[markidx++] = mpi_alloc_limb_space(dsize, mpi_is_secure(den));
- MPN_COPY( tp, dp, dsize );
- dp = tp;
- }
-
- /* Move the numerator to the remainder. */
- if( rp != np )
- MPN_COPY(rp, np, nsize);
-
- rsize = nsize;
- }
-
- q_limb = mpihelp_divrem( qp, 0, rp, rsize, dp, dsize );
-
- if( quot ) {
- qsize = rsize - dsize;
- if(q_limb) {
- qp[qsize] = q_limb;
- qsize += 1;
- }
-
- quot->nlimbs = qsize;
- quot->sign = sign_quotient;
- }
-
- rsize = dsize;
- MPN_NORMALIZE (rp, rsize);
-
- if( normalization_steps && rsize ) {
- mpihelp_rshift(rp, rp, rsize, normalization_steps);
- rsize -= rp[rsize - 1] == 0?1:0;
- }
-
- rem->nlimbs = rsize;
- rem->sign = sign_remainder;
- while( markidx )
- mpi_free_limb_space(marker[--markidx]);
-}
-
-void
-mpi_tdiv_q_2exp( MPI w, MPI u, unsigned count )
-{
- mpi_size_t usize, wsize;
- mpi_size_t limb_cnt;
-
- usize = u->nlimbs;
- limb_cnt = count / BITS_PER_MPI_LIMB;
- wsize = usize - limb_cnt;
- if( limb_cnt >= usize )
- w->nlimbs = 0;
- else {
- mpi_ptr_t wp;
- mpi_ptr_t up;
-
- RESIZE_IF_NEEDED( w, wsize );
- wp = w->d;
- up = u->d;
-
- count %= BITS_PER_MPI_LIMB;
- if( count ) {
- mpihelp_rshift( wp, up + limb_cnt, wsize, count );
- wsize -= !wp[wsize - 1];
- }
- else {
- MPN_COPY_INCR( wp, up + limb_cnt, wsize);
- }
-
- w->nlimbs = wsize;
- }
-}
-
-/****************
- * Check whether dividend is divisible by divisor
- * (note: divisor must fit into a limb)
- */
-int
-mpi_divisible_ui(MPI dividend, ulong divisor )
-{
- return !mpihelp_mod_1( dividend->d, dividend->nlimbs, divisor );
-}
-
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