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