http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55539
--- Comment #3 from Harald Anlauf <anlauf at gmx dot de> 2012-12-11 22:33:21
UTC ---
(In reply to comment #2)
I played a little bit with the code and found that the
following patch appears to fix my problem:
Index: libgfortran/io/write_float.def
===================================================================
--- libgfortran/io/write_float.def (revision 194417)
+++ libgfortran/io/write_float.def (working copy)
@@ -492,7 +492,7 @@
/* To format properly, we need to know if the rounded result is zero and if
so, we set the zero_flag which may have been already set for
actual zero. */
- if (i == ndigits)
+ if (i == ndigits && (digits[i] == '0' || digits[i] == '.'))
{
zero_flag = true;
/* The output is zero, so set the sign according to the sign bit unless
Testcase:
implicit none
real :: x = 0.5 + epsilon(0.)
character(len=80) :: line
print '(7f5.1)', x, -x
write (line,'(2f5.1)') x, -x
print '(A)', line
if (line /= " 0.5 -0.5") call abort ()
print '(7f5.0)', x, -x
write (line,'(2f5.0)') x, -x
print '(A)', line
if (line /= " 1. -1.") call abort ()
end
Strangely enough I needed to add some epsilon to 0.5 so that
the second test passes, because the exact value 0.5 appears
to get rounded down to 0 in formatted output.
