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From: "s.cecilio at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/49048] New: setprecision rounding fails in some cases
Date: Wed, 18 May 2011 17:49:00 -0000	[thread overview]
Message-ID: <bug-49048-4@http.gcc.gnu.org/bugzilla/> (raw)

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49048

           Summary: setprecision rounding fails in some cases
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: s.cecilio@gmail.com


cecilio@pp1:~$ gcc --version
gcc (Ubuntu 4.4.3-4ubuntu5) 4.4.3

I'm having problems with truncation. For instance, following code:

        cout << "test precision 5798.12500: "
                  << fixed << setprecision(2) << setfill(' ')
                  << setw(10) << 5798.12500 << endl;

        cout << "test precision 5798.87500: "
                  << fixed << setprecision(2) << setfill(' ')
                  << setw(10) << 5798.87500 << endl;

Generates inconsistent results: 5798.12 (wrong, should be 5798.13) and 5798.88
(right).
In first case rounds up and in second, down.

The same code, compiled with Microsft Visual Studio, produces the right results
in the same machine.


             reply	other threads:[~2011-05-18 17:46 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-18 17:49 s.cecilio at gmail dot com [this message]
2011-05-18 18:26 ` [Bug libstdc++/49048] " paolo.carlini at oracle dot com
2011-05-18 20:43 ` s.cecilio at gmail dot com
2011-05-18 21:09 ` paolo.carlini at oracle dot com
2011-05-19  6:22 ` s.cecilio at gmail dot com
2011-05-19  6:51 ` jakub at gcc dot gnu.org
2011-05-19  7:53 ` s.cecilio at gmail dot com
2011-05-19  9:00 ` paolo.carlini at oracle dot com
2011-05-19 17:22 ` s.cecilio at gmail dot com

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