--- a/libtommath/bn_mp_count_bits.c	Thu Mar 21 23:28:59 2019 +0800
+++ b/libtommath/bn_mp_count_bits.c	Fri Jun 26 21:07:34 2020 +0800
@@ -1,45 +1,28 @@
-#include <tommath_private.h>
+#include "tommath_private.h"
 #ifdef BN_MP_COUNT_BITS_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 */
 
 /* returns the number of bits in an int */
-int
-mp_count_bits (mp_int * a)
+int mp_count_bits(const mp_int *a)
 {
-  int     r;
-  mp_digit q;
+   int     r;
+   mp_digit q;
 
-  /* shortcut */
-  if (a->used == 0) {
-    return 0;
-  }
+   /* shortcut */
+   if (MP_IS_ZERO(a)) {
+      return 0;
+   }
 
-  /* get number of digits and add that */
-  r = (a->used - 1) * DIGIT_BIT;
-  
-  /* take the last digit and count the bits in it */
-  q = a->dp[a->used - 1];
-  while (q > ((mp_digit) 0)) {
-    ++r;
-    q >>= ((mp_digit) 1);
-  }
-  return r;
+   /* get number of digits and add that */
+   r = (a->used - 1) * MP_DIGIT_BIT;
+
+   /* take the last digit and count the bits in it */
+   q = a->dp[a->used - 1];
+   while (q > 0u) {
+      ++r;
+      q >>= 1u;
+   }
+   return r;
 }
 #endif
-
-/* ref:         $Format:%D$ */
-/* git commit:  $Format:%H$ */
-/* commit time: $Format:%ai$ */