dropbear/libtommath/bn_mp_signed_rsh.c
Steffen Jaeckel b4bd23b4d2
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.
2020-05-26 23:36:47 +08:00

23 lines
553 B
C

#include "tommath_private.h"
#ifdef BN_MP_SIGNED_RSH_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* shift right by a certain bit count with sign extension */
mp_err mp_signed_rsh(const mp_int *a, int b, mp_int *c)
{
mp_err res;
if (a->sign == MP_ZPOS) {
return mp_div_2d(a, b, c, NULL);
}
res = mp_add_d(a, 1uL, c);
if (res != MP_OKAY) {
return res;
}
res = mp_div_2d(c, b, c, NULL);
return (res == MP_OKAY) ? mp_sub_d(c, 1uL, c) : res;
}
#endif