Re: [Valgrind-users] mysterious failures when using valgrind

[Peter v. H. <p.v...@om...>]

On 2013-09-25 06:59, Vasily Golubev wrote:
> It may be helpful to test Valgrind's trunk from svn repository, at first.

I am sure this would be a very quick test for you. For me this would be 
a lot of work as I don't have a trunk version of valgrind handy.

Cheers,

Peter.

> On Tue, Sep 24, 2013 at 7:55 PM, John Reiser <jr...@bi...> wrote:
>>> __float128 exp10(__float128);
>>>
>>> When that routine is called with a negative argument, the return value
>>> changes when I run the code through valgrind, e.g.
>>>
>>> -20 3fbc79ca10c9242235d511e976394d7a (without valgrind)
>>> -20 3fbc79ca10c9240e12445f2000000000 (with valgrind)
>>>
>>> The -20 is the argument for exp10() and was obviously converted to
>>> __float128, and the return value is printed here in hex format.
>>> Initially I thought that the lowest 64 bits were mangled, but from this
>>> example you can see that it is a bit more (the lowest 70 bits differ).
>>
>> This is a bug in memcheck.  Please file a bug report.
>> Construct a short test case program (15 lines or so)
>> which reproduces the output above.  Then go to the main page
>> http://www.valgrind.org/ , click on the Bug Reports link
>> (left column under Contact), describe the problem (much as above),
>> copy+paste the output, and attach the test case program.
>> Please also include the versions of valgrind, compiler, C/math library,
>> and operating system; and kind of hardware.
>> Thank you.
>>
>> --
>>
>>
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>
>
>

-- 
Peter van Hoof
Royal Observatory of Belgium
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Belgium
http://homepage.oma.be/pvh