[Bug math/13705] New: Bogus FPE on underflow for exp(double)

[Bug math/13705] New: Bogus FPE on underflow for exp(double)

[law at redhat dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13705

             Bug #: 13705
           Summary: Bogus FPE on underflow for exp(double)
           Product: glibc
           Version: 2.15
            Status: NEW
          Severity: normal
          Priority: P2
         Component: math
        AssignedTo: aj@suse.de
        ReportedBy: law@redhat.com
    Classification: Unclassified


Created attachment 6225
  --> http://sourceware.org/bugzilla/attachment.cgi?id=6225
testcase

With floating point trapping enabled, *except* for "underflow"
and "inexact", exp(-1.0e40) will throw a Floating Point Exception.

How reproducible:
Every time.

Steps to Reproduce:
1. Compile attached test programme (g++ test1.cpp)
2. Run program
3.

Actual results:
Floating point exception.

Expected results:
The value 0 should be printed.

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[Bug math/13705] Bogus FPE on underflow for exp(double)

[aurelien at aurel32 dot net]

http://sourceware.org/bugzilla/show_bug.cgi?id=13705

Aurelien Jarno <aurelien at aurel32 dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aurelien at aurel32 dot net
         AssignedTo|aj at suse dot de           |aurelien at aurel32 dot net

--- Comment #1 from Aurelien Jarno <aurelien at aurel32 dot net> 2012-02-18 12:15:48 UTC ---
This should be fixed by:

http://sourceware.org/ml/libc-alpha/2012-02/msg00299.html

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[Bug math/13705] Bogus FPE on underflow for exp(double)

[aurelien at aurel32 dot net]

http://sourceware.org/bugzilla/show_bug.cgi?id=13705

--- Comment #2 from Aurelien Jarno <aurelien at aurel32 dot net> 2012-02-20 06:34:17 UTC ---
This is a different bug than the one fixed by the link I gave above.

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[Bug math/13705] Bogus FPE on underflow for exp(double)

[rjrw at waitrose dot com]

http://sourceware.org/bugzilla/show_bug.cgi?id=13705

rjrw at waitrose dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rjrw at waitrose dot com

--- Comment #3 from rjrw at waitrose dot com 2012-02-20 22:32:43 UTC ---
At lines 35 and 40 of w_exp.c, libm uses the floating point variant
"kernel_standard_f" rather than the double variant "kernel_standard".

The implementation of kernel_standard_f in k_standard.c just maps double to
float (for arguments and return value).  If kernel_standard_f is changed to
kernel_standard in both places, the test program runs through without problems.

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[Bug math/13705] Bogus FPE on underflow for exp(double)

[aurelien at aurel32 dot net]

http://sourceware.org/bugzilla/show_bug.cgi?id=13705

Aurelien Jarno <aurelien at aurel32 dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED

--- Comment #4 from Aurelien Jarno <aurelien at aurel32 dot net> 2012-02-21 13:52:31 UTC ---
Patches posted on:

http://sourceware.org/ml/libc-alpha/2012-02/msg00446.html

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[Bug math/13705] Bogus FPE on underflow for exp(double)

[aj at suse dot de]

http://sourceware.org/bugzilla/show_bug.cgi?id=13705

Andreas Jaeger <aj at suse dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Attachment #6225|text/x-c++src               |text/plain
          mime type|                            |

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[Bug math/13705] Bogus FPE on underflow for exp(double)

[jsm28 at gcc dot gnu.org]

http://sourceware.org/bugzilla/show_bug.cgi?id=13705

Joseph Myers <jsm28 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #5 from Joseph Myers <jsm28 at gcc dot gnu.org> 2012-04-08 22:50:24 UTC ---
I have committed this patch as:

commit f77f12320635155da728a3c1adb75ff9914cf686
Author: Aurelien Jarno <aurelien@aurel32.net>
Date:   Sun Apr 8 22:45:13 2012 +0000

    Use __kernel_standard instead of __kernel_standard_f in exp wrapper (bug
13705).

and the obvious testcase patch for it as:

commit d2de7579f257386ba5c28dfca94fa8aef143b4e0
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Sun Apr 8 22:46:49 2012 +0000

    Do not allow overflow exception on exp underflow test (bug 13705).

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[Bug math/13705] Bogus FPE on underflow for exp(double)

[fweimer at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=13705

Florian Weimer <fweimer at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
              Flags|                            |security-

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