Re: log2 on MinGW

[Rik]

On 11/04/2013 09:54 AM, John W. Eaton wrote:
> On 11/04/2013 12:05 PM, Rik wrote:
>
>> Aside from performance, does using gnulib::frexp solve the original
>> problem? The gnulib documentation is somewhat minimal and they suggest
>> that they only replace an existing library function if the function is
>> buggy. Otherwise, they fall back on the library version that is
>> available. This may be, however, only when you use the bare function
>> such as 'frexp' rather than the namespace-qualified version
>> 'gnulib::frexp'.
>
> The namespace thing allows gnulib to replace the function in C++ code
> without introducing macros that screw things up in other places.  But the
> replacement code is still only used if needed.  It works by using a
> function pointer in the namespace that either refers to the replacement
> function (usually called rpl_FOO) or the system function FOO.  So there
> shouldn't be much of a penalty if the system function is used.
Philip,

Can you test the solution which is in Mercurial with MinGW?  It is possible
that gnulib doesn't identify the frexp on Windows as being buggy (since it
works for ordinary values) in which case it won't replace it with the
correct version.

--Rik