summary refs log tree commit diff
path: root/lib/mpi/mpi-div.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/mpi/mpi-div.c')
-rw-r--r--lib/mpi/mpi-div.c338
1 files changed, 0 insertions, 338 deletions
diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c
deleted file mode 100644
index f68cbbb4d4a4..000000000000
--- a/lib/mpi/mpi-div.c
+++ /dev/null
@@ -1,338 +0,0 @@
-/* mpi-div.c  -  MPI functions
- *	Copyright (C) 1994, 1996 Free Software Foundation, Inc.
- *	Copyright (C) 1998, 1999, 2000, 2001 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 <linux/string.h>
-#include "mpi-internal.h"
-#include "longlong.h"
-
-int mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor)
-{
-	int rc = -ENOMEM;
-	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) {
-		if (mpi_copy(&temp_divisor, divisor) < 0)
-			goto nomem;
-		divisor = temp_divisor;
-	}
-
-	if (mpi_tdiv_qr(NULL, rem, dividend, divisor) < 0)
-		goto nomem;
-	if (((divisor_sign ? 1 : 0) ^ (dividend->sign ? 1 : 0)) && rem->nlimbs)
-		if (mpi_add(rem, rem, divisor) < 0)
-			goto nomem;
-
-	rc = 0;
-
-nomem:
-	if (temp_divisor)
-		mpi_free(temp_divisor);
-	return rc;
-}
-
-/****************
- * 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;
-}
-
-int mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor)
-{
-	MPI tmp = mpi_alloc(mpi_get_nlimbs(quot));
-	if (!tmp)
-		return -ENOMEM;
-	mpi_fdiv_qr(quot, tmp, dividend, divisor);
-	mpi_free(tmp);
-	return 0;
-}
-
-int 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) {
-		if (mpi_copy(&temp_divisor, divisor) < 0)
-			return -ENOMEM;
-		divisor = temp_divisor;
-	}
-
-	if (mpi_tdiv_qr(quot, rem, dividend, divisor) < 0)
-		goto nomem;
-
-	if ((divisor_sign ^ dividend->sign) && rem->nlimbs) {
-		if (mpi_sub_ui(quot, quot, 1) < 0)
-			goto nomem;
-		if (mpi_add(rem, rem, divisor) < 0)
-			goto nomem;
-	}
-
-	if (temp_divisor)
-		mpi_free(temp_divisor);
-
-	return 0;
-
-nomem:
-	mpi_free(temp_divisor);
-	return -ENOMEM;
-}
-
-/* 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.
- */
-
-int mpi_tdiv_r(MPI rem, MPI num, MPI den)
-{
-	return mpi_tdiv_qr(NULL, rem, num, den);
-}
-
-int mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
-{
-	int rc = -ENOMEM;
-	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;
-
-	if (!dsize)
-		return -EINVAL;
-
-	memset(marker, 0, sizeof(marker));
-
-	/* 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;
-	if (mpi_resize(rem, rsize) < 0)
-		goto nomem;
-
-	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 0;
-	}
-
-	if (quot)
-		if (mpi_resize(quot, qsize) < 0)
-			goto nomem;
-
-	/* 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 0;
-	}
-
-	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);
-			if (!np)
-				goto nomem;
-			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);
-		if (!tp)
-			goto nomem;
-		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);
-			if (!tp)
-				goto nomem;
-			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;
-
-	rc = 0;
-nomem:
-	while (markidx)
-		mpi_free_limb_space(marker[--markidx]);
-	return rc;
-}
-
-int 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;
-
-		if (RESIZE_IF_NEEDED(w, wsize) < 0)
-			return -ENOMEM;
-		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;
-	}
-	return 0;
-}
-
-/****************
- * 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);
-}