--- a/gcc/gcov-iov.c	Sun Aug 21 07:07:55 2011 +0900
+++ b/gcc/gcov-iov.c	Fri Oct 27 22:46:09 2017 +0900
@@ -1,6 +1,6 @@
 /* Generate gcov version string from version.c. See gcov-io.h for
    description of how the version string is generated.
-   Copyright (C) 2002, 2003, 2005, 2007, 2010 Free Software Foundation, Inc.
+   Copyright (C) 2002-2017 Free Software Foundation, Inc.
    Contributed by Nathan Sidwell <nathan@codesourcery.com>
 
 This file is part of GCC.
@@ -19,8 +19,8 @@
 along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
-#include <stdio.h>
-#include <stdlib.h>
+#include "bconfig.h"
+#include "system.h"
 
 /* Command line arguments are the base GCC version and the development
    phase (the latter may be an empty string).  */
@@ -48,13 +48,19 @@
   if (*ptr == '.')
     minor = strtoul (ptr + 1, 0, 10);
 
+  /* For releases the development phase is an empty string, for
+     prerelease versions on a release branch it is "prerelease".
+     Consider both equal as patch-level releases do not change
+     the GCOV version either.
+     On the trunk the development phase is "experimental".  */
   phase = argv[2][0];
-  if (phase == '\0')
+  if (phase == '\0'
+      || strcmp (argv[2], "prerelease") == 0)
     phase = '*';
 
-  v[0] = (major < 10 ? '0' : 'A' - 10) + major;
-  v[1] = (minor / 10) + '0';
-  v[2] = (minor % 10) + '0';
+  v[0] = (major / 10) + 'A';
+  v[1] = (major % 10) + '0';
+  v[2] = minor + '0';
   v[3] = phase;
 
   for (ix = 0; ix != 4; ix++)