Re: FYI: quadmath.h's expq() crashes at runtime

Hi Rob,

On 5.10.2013 17:06, [email protected] wrote:
> Hi,
>
> It's no big deal, but current Strawberry Perl 32-bit and 64-bit compilers 
> create executables that crash when expq() is called.
>
> Here's the minimalistic demo script:
>
> ####################
> #include <quadmath.h>
>
> int main (void) {
>  __float128 r;
>
>  r = expq(2.0Q);
>  r = sqrtq(2.0Q);
>  r = fabsq(2.0Q);
>  r = sinq(2.0Q);
>  r = logq(2.0Q);
>  r = cosq(2.0Q);
>
>  return 0;
> }
>
> ####################
>
> The resultant executable crashes when run, but remove the expq() call and 
> there's no problem. (Link to -lquadmath when building the above program.)
>
> It's not just MinGW64's gcc-4.6.3 compilers that are affected. I find the 
> same with their 64-bit gcc-4.7.0, and 4.8.1 compilers. (I haven't tested 
> any other MinGW64 compilers.)
>
> I've also found that mingw.org's gcc-4.7.0 does *not* suffer this 
> problem; nor does Ubuntu's gcc-4.6.3 ... so I guess I probably should 
> report this to the mingw64 project.
>
> BTW, the perl relevance here is that, because of this bug, Math::Float128 
> crashes its test suite when expq() gets called. But I don't think that 
> there's a high demand for this module, so I wouldn't be too concerned 
> about that aspect.

I am afraid I cannot do much about expq crash unless there is newer version 
of gcc and/or mingw-w64 runtime which does not suffer from this.


>
> Also of slight relevance to Strawberry Perl is the fact that 
> c/lib/gcc/[whatever]-w64-mingw32/4.6.3 is not in $Config{libpth}.
> As a consequence perl does not automatically find -lquadmath when the 
> Math::Float128 Makefile.PL is run, and perl therefore removes the link. 
> (The gcc linker can find -lquadmath without any help at all ... but it 
> won't look for that library if perl has removed the link.)

As for this part you mean using something like this:

libpth='C:\strawberry\c\lib C:\strawberry\c\x86_64-w64-mingw32\lib 
C:\strawberry\c\lib\gcc\x86_64-w64-mingw32\4.7.3'

right?

--
kmx