Mercurial > dropbear
diff libtommath/bn_mp_signed_rsh.c @ 1692:1051e4eea25a
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.
| author | Steffen Jaeckel <s@jaeckel.eu> |
|---|---|
| date | Tue, 26 May 2020 17:36:47 +0200 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libtommath/bn_mp_signed_rsh.c Tue May 26 17:36:47 2020 +0200 @@ -0,0 +1,22 @@ +#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