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authorSteffen Jaeckel <s@jaeckel.eu>2020-05-26 17:36:47 +0200
committerGitHub <noreply@github.com>2020-05-26 23:36:47 +0800
commitb4bd23b4d2a4c640880b49069e02cd598dd03416 (patch)
treefb480b4e501cc69b305de95fb15259aa6afa1963 /libtommath/bn_mp_n_root_ex.c
parent724e61f8ae9e9f216b0252e41c5ebd5d64ad79a6 (diff)
Update LibTomMath to 1.2.0 (#84)
* update C files * update other files * update headers * update makefiles * remove mp_set/get_double() * use ltm 1.2.0 API * update ltm_desc * use bundled tommath if system-tommath is too old * XMALLOC etc. were changed to MP_MALLOC etc.
Diffstat (limited to 'libtommath/bn_mp_n_root_ex.c')
-rw-r--r--libtommath/bn_mp_n_root_ex.c129
1 files changed, 0 insertions, 129 deletions
diff --git a/libtommath/bn_mp_n_root_ex.c b/libtommath/bn_mp_n_root_ex.c
deleted file mode 100644
index 720cb2f..0000000
--- a/libtommath/bn_mp_n_root_ex.c
+++ /dev/null
@@ -1,129 +0,0 @@
-#include "tommath_private.h"
-#ifdef BN_MP_N_ROOT_EX_C
-/* LibTomMath, multiple-precision integer library -- Tom St Denis
- *
- * LibTomMath is a library that provides multiple-precision
- * integer arithmetic as well as number theoretic functionality.
- *
- * The library was designed directly after the MPI library by
- * Michael Fromberger but has been written from scratch with
- * additional optimizations in place.
- *
- * SPDX-License-Identifier: Unlicense
- */
-
-/* find the n'th root of an integer
- *
- * Result found such that (c)**b <= a and (c+1)**b > a
- *
- * This algorithm uses Newton's approximation
- * x[i+1] = x[i] - f(x[i])/f'(x[i])
- * which will find the root in log(N) time where
- * each step involves a fair bit. This is not meant to
- * find huge roots [square and cube, etc].
- */
-int mp_n_root_ex(const mp_int *a, mp_digit b, mp_int *c, int fast)
-{
- mp_int t1, t2, t3, a_;
- int res;
-
- /* input must be positive if b is even */
- if (((b & 1u) == 0u) && (a->sign == MP_NEG)) {
- return MP_VAL;
- }
-
- if ((res = mp_init(&t1)) != MP_OKAY) {
- return res;
- }
-
- if ((res = mp_init(&t2)) != MP_OKAY) {
- goto LBL_T1;
- }
-
- if ((res = mp_init(&t3)) != MP_OKAY) {
- goto LBL_T2;
- }
-
- /* if a is negative fudge the sign but keep track */
- a_ = *a;
- a_.sign = MP_ZPOS;
-
- /* t2 = 2 */
- mp_set(&t2, 2uL);
-
- do {
- /* t1 = t2 */
- if ((res = mp_copy(&t2, &t1)) != MP_OKAY) {
- goto LBL_T3;
- }
-
- /* t2 = t1 - ((t1**b - a) / (b * t1**(b-1))) */
-
- /* t3 = t1**(b-1) */
- if ((res = mp_expt_d_ex(&t1, b - 1u, &t3, fast)) != MP_OKAY) {
- goto LBL_T3;
- }
-
- /* numerator */
- /* t2 = t1**b */
- if ((res = mp_mul(&t3, &t1, &t2)) != MP_OKAY) {
- goto LBL_T3;
- }
-
- /* t2 = t1**b - a */
- if ((res = mp_sub(&t2, &a_, &t2)) != MP_OKAY) {
- goto LBL_T3;
- }
-
- /* denominator */
- /* t3 = t1**(b-1) * b */
- if ((res = mp_mul_d(&t3, b, &t3)) != MP_OKAY) {
- goto LBL_T3;
- }
-
- /* t3 = (t1**b - a)/(b * t1**(b-1)) */
- if ((res = mp_div(&t2, &t3, &t3, NULL)) != MP_OKAY) {
- goto LBL_T3;
- }
-
- if ((res = mp_sub(&t1, &t3, &t2)) != MP_OKAY) {
- goto LBL_T3;
- }
- } while (mp_cmp(&t1, &t2) != MP_EQ);
-
- /* result can be off by a few so check */
- for (;;) {
- if ((res = mp_expt_d_ex(&t1, b, &t2, fast)) != MP_OKAY) {
- goto LBL_T3;
- }
-
- if (mp_cmp(&t2, &a_) == MP_GT) {
- if ((res = mp_sub_d(&t1, 1uL, &t1)) != MP_OKAY) {
- goto LBL_T3;
- }
- } else {
- break;
- }
- }
-
- /* set the result */
- mp_exch(&t1, c);
-
- /* set the sign of the result */
- c->sign = a->sign;
-
- res = MP_OKAY;
-
-LBL_T3:
- mp_clear(&t3);
-LBL_T2:
- mp_clear(&t2);
-LBL_T1:
- mp_clear(&t1);
- return res;
-}
-#endif
-
-/* ref: HEAD -> master, tag: v1.1.0 */
-/* git commit: 08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
-/* commit time: 2019-01-28 20:32:32 +0100 */