isfinite() failure on Cygwin with gcc 3.4.1

[Jeff Johnston]

A fix has been checked in to avoid using the same input variable names for these 
macros which nest.

-- Jeff J.

William M. (Mike) Miller wrote:
> Andrew Pinski wrote:
> 
>> Lets look at the definition of the macros again:
>>
>>
>>> #define fpclassify(x) \
>>>          (__extension__ ({__typeof__(x) __x = (x); \
>>>                           (sizeof (__x) == sizeof (float))  ? 
>>> __fpclassifyf(__x) : __fpclassifyd(__x);}))
>>>
>>> #define isfinite(x) \
>>>          (__extension__ ({__typeof__(x) __x = (x); \
>>>                           fpclassify(__x) != FP_INFINITE && 
>>> fpclassify(__x) != FP_NAN;}))
>>
>>
>>
>> See how we pass __x to fpclassify, well when we preprocessed the 
>> source we get in there:
>> __typeof__(x) __x = (__x); which just makes this uninitialized.  The 
>> reason why we
>> don't warn about it in gcc is because int a = a; is documented to have 
>> the uninitilizated
>> warnings to go away.
>>
>> Thanks,
>> Andrew Pinski
>> a gcc developer and a gcc bug master
> 
> 
> Aha, mystery solved!  (*smacking forehead*) I should have noticed that 
> -- would have made for a shorter bug report.  Thanks for looking into it.
>