--- a/libtommath/bn_mp_lshd.c	Tue May 26 23:27:26 2020 +0800
+++ b/libtommath/bn_mp_lshd.c	Tue May 26 17:36:47 2020 +0200
@@ -1,68 +1,51 @@
 #include "tommath_private.h"
 #ifdef BN_MP_LSHD_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.
- *
- * SPDX-License-Identifier: Unlicense
- */
+/* LibTomMath, multiple-precision integer library -- Tom St Denis */
+/* SPDX-License-Identifier: Unlicense */
 
 /* shift left a certain amount of digits */
-int mp_lshd(mp_int *a, int b)
+mp_err mp_lshd(mp_int *a, int b)
 {
-   int     x, res;
+   int x;
+   mp_err err;
+   mp_digit *top, *bottom;
 
    /* if its less than zero return */
    if (b <= 0) {
       return MP_OKAY;
    }
    /* no need to shift 0 around */
-   if (mp_iszero(a) == MP_YES) {
+   if (MP_IS_ZERO(a)) {
       return MP_OKAY;
    }
 
    /* grow to fit the new digits */
    if (a->alloc < (a->used + b)) {
-      if ((res = mp_grow(a, a->used + b)) != MP_OKAY) {
-         return res;
+      if ((err = mp_grow(a, a->used + b)) != MP_OKAY) {
+         return err;
       }
    }
 
-   {
-      mp_digit *top, *bottom;
-
-      /* increment the used by the shift amount then copy upwards */
-      a->used += b;
+   /* increment the used by the shift amount then copy upwards */
+   a->used += b;
 
-      /* top */
-      top = a->dp + a->used - 1;
+   /* top */
+   top = a->dp + a->used - 1;
 
-      /* base */
-      bottom = (a->dp + a->used - 1) - b;
+   /* base */
+   bottom = (a->dp + a->used - 1) - b;
 
-      /* much like mp_rshd this is implemented using a sliding window
-       * except the window goes the otherway around.  Copying from
-       * the bottom to the top.  see bn_mp_rshd.c for more info.
-       */
-      for (x = a->used - 1; x >= b; x--) {
-         *top-- = *bottom--;
-      }
+   /* much like mp_rshd this is implemented using a sliding window
+    * except the window goes the otherway around.  Copying from
+    * the bottom to the top.  see bn_mp_rshd.c for more info.
+    */
+   for (x = a->used - 1; x >= b; x--) {
+      *top-- = *bottom--;
+   }
 
-      /* zero the lower digits */
-      top = a->dp;
-      for (x = 0; x < b; x++) {
-         *top++ = 0;
-      }
-   }
+   /* zero the lower digits */
+   MP_ZERO_DIGITS(a->dp, b);
+
    return MP_OKAY;
 }
 #endif
-
-/* ref:         HEAD -> master, tag: v1.1.0 */
-/* git commit:  08549ad6bc8b0cede0b357a9c341c5c6473a9c55 */
-/* commit time: 2019-01-28 20:32:32 +0100 */