re PR libfortran/17143 (2**63 prints garbage)

2004-08-24  Bud Davis  <bdavis9659@comcast.net>

        PR fortran/17143
        * runtime/error.c (itoa): keep from overflowing during
        mod operation by using unsigned variable.

        * gfortran.dg/pr17143.f90: New test.

From-SVN: r86532

gcc/testsuite/ChangeLog

 2004-08-24  Bud Davis  <bdavis9659@comcast.net>
 
+	PR fortran/17143
+	* gfortran.dg/pr17143.f90: New test.
+
+2004-08-24  Bud Davis  <bdavis9659@comcast.net>
+
 	PR fortran/17164
 	* gfortran.dg/pr17164.f90: New test.
 

gcc/testsuite/gfortran.dg/pr17143.f90

+! pr17143
+! does not print 2*63 correctly
+       character*25 l
+       integer*8 i
+       data i /1/
+       do j = 1,63
+          i = i * 2
+       end do
+       write(l,*)i
+       if (l.ne.' -9223372036854775808') then
+!                ^
+!         the space is required before a number
+          call abort
+       endif 
+       end
+

libgfortran/ChangeLog

 2004-08-24  Bud Davis  <bdavis9659@comcast.net>
 
+	PR fortran/17143	
+	* runtime/error.c (itoa): keep from overflowing during
+        mod operation by using unsigned variable.
+
+2004-08-24  Bud Davis  <bdavis9659@comcast.net>
+
 	PR fortran/17164
 	* runtime/string_intrinsics.c (string_index):check for
 	substring longer than string.

libgfortran/runtime/error.c

@@ -117,6 +117,7 @@ itoa (int64_t n)
 {
   int negative;
   char *p;
+  uint64_t t;
 
   if (n == 0)
     {
@@ -126,19 +127,20 @@ itoa (int64_t n)
     }
 
   negative = 0;
+  t = n;
   if (n < 0)
     {
       negative = 1;
-      n = -n;
+      t = -n; /*must use unsigned to protect from overflow*/
     }
 
   p = buffer + sizeof (buffer) - 1;
   *p-- = '\0';
 
-  while (n != 0)
+  while (t != 0)
     {
-      *p-- = '0' + (n % 10);
-      n /= 10;
+      *p-- = '0' + (t % 10);
+      t /= 10;
     }
 
   if (negative)