diff --git a/gcc/fortran/error.cc b/gcc/fortran/error.cc
index c346552235b..65e38b0e866 100644
--- a/gcc/fortran/error.cc
+++ b/gcc/fortran/error.cc
@@ -886,13 +886,14 @@ error_print (const char *type, const char *format0, va_list argp)
 	  format++;
 	  if (*format == 'u')
 	    {
-	      ptrdiff_t ptrdiffval = spec[n++].u.ptrdiffval;
-	      if (sizeof (ptrdiff_t) == sizeof (int))
-		error_uinteger ((unsigned) ptrdiffval);
-	      else if (sizeof (ptrdiff_t) == sizeof (long))
-		error_uinteger ((unsigned long) ptrdiffval);
-	      else
-		error_uinteger (ptrdiffval);
+	      unsigned long long a = spec[n++].u.ptrdiffval, m;
+#ifdef PTRDIFF_MAX
+	      m = PTRDIFF_MAX;
+#else
+	      m = INTTYPE_MAXIMUM (ptrdiff_t);
+#endif
+	      m = 2 * m + 1;  
+	      error_uinteger (a & m);
 	    }
 	  else
 	    error_integer (spec[n++].u.ptrdiffval);
diff --git a/gcc/pretty-print.cc b/gcc/pretty-print.cc
index 825175787a8..67c213bbaf2 100644
--- a/gcc/pretty-print.cc
+++ b/gcc/pretty-print.cc
@@ -752,6 +752,9 @@ output_buffer::~output_buffer ()
   obstack_free (&formatted_obstack, NULL);
 }
 
+#ifndef PTRDIFF_MAX
+#define PTRDIFF_MAX INTTYPE_MAXIMUM (ptrdiff_t)
+#endif
 
 /* Format an integer given by va_arg (ARG, type-specifier T) where
    type-specifier is a precision modifier as indicated by PREC.  F is
@@ -783,7 +786,15 @@ output_buffer::~output_buffer ()
         break;                                               \
                                                              \
       case 4:                                                \
-        if (sizeof (ptrdiff_t) <= sizeof (int))              \
+        if (T (-1) >= T (0))                                 \
+          {                                                  \
+            unsigned long long a = va_arg (ARG, ptrdiff_t);  \
+            unsigned long long m = PTRDIFF_MAX;              \
+            m = 2 * m + 1;                                   \
+            pp_scalar (PP, "%" HOST_LONG_LONG_FORMAT F,      \
+		       a & m);                               \
+          }                                                  \
+        else if (sizeof (ptrdiff_t) <= sizeof (int))         \
           pp_scalar (PP, "%" F,                              \
                      (int) va_arg (ARG, ptrdiff_t));         \
         else if (sizeof (ptrdiff_t) <= sizeof (long))        \