23 lines
553 B
C
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
|