--- a/libtommath/bn_mp_reduce_2k.c	Wed Feb 28 22:11:39 2018 +0800
+++ b/libtommath/bn_mp_reduce_2k.c	Thu Oct 15 19:55:15 2020 +0800
@@ -1,63 +1,48 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
 #ifdef BN_MP_REDUCE_2K_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.
- *
- * The library is free for all purposes without any express
- * guarantee it works.
- *
- * Tom St Denis, [email protected], http://libtom.org
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
 
 /* reduces a modulo n where n is of the form 2**p - d */
-int mp_reduce_2k(mp_int *a, mp_int *n, mp_digit d)
+mp_err mp_reduce_2k(mp_int *a, const mp_int *n, mp_digit d)
 {
    mp_int q;
-   int    p, res;
+   mp_err err;
+   int    p;
 
-   if ((res = mp_init(&q)) != MP_OKAY) {
-      return res;
+   if ((err = mp_init(&q)) != MP_OKAY) {
+      return err;
    }
 
    p = mp_count_bits(n);
 top:
    /* q = a/2**p, a = a mod 2**p */
-   if ((res = mp_div_2d(a, p, &q, a)) != MP_OKAY) {
-      goto ERR;
+   if ((err = mp_div_2d(a, p, &q, a)) != MP_OKAY) {
+      goto LBL_ERR;
    }
 
-   if (d != 1) {
+   if (d != 1u) {
       /* q = q * d */
-      if ((res = mp_mul_d(&q, d, &q)) != MP_OKAY) {
-         goto ERR;
+      if ((err = mp_mul_d(&q, d, &q)) != MP_OKAY) {
+         goto LBL_ERR;
       }
    }
 
    /* a = a + q */
-   if ((res = s_mp_add(a, &q, a)) != MP_OKAY) {
-      goto ERR;
+   if ((err = s_mp_add(a, &q, a)) != MP_OKAY) {
+      goto LBL_ERR;
    }
 
    if (mp_cmp_mag(a, n) != MP_LT) {
-      if ((res = s_mp_sub(a, n, a)) != MP_OKAY) {
-         goto ERR;
+      if ((err = s_mp_sub(a, n, a)) != MP_OKAY) {
+         goto LBL_ERR;
       }
       goto top;
    }
 
-ERR:
+LBL_ERR:
    mp_clear(&q);
-   return res;
+   return err;
 }
 
 #endif
-
-/* ref:         $Format:%D$ */
-/* git commit:  $Format:%H$ */
-/* commit time: $Format:%ai$ */