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Re: perl-5.29.3 breaks "long double" mingw builds on MS Windows

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From:
sisyphus
Date:
September 21, 2018 15:18
Subject:
Re: perl-5.29.3 breaks "long double" mingw builds on MS Windows
Message ID:
CADZSBj1i+2tw8SJn=2ZSZe_O0SjC+PiS=S4Q26g8xvAkU-r6nQ@mail.gmail.com
I suspect (untested) that the problem lies with this section of POSIX.xs in
the 5.29.3 source:

NV
ldexp(x,exp)
 NV  x
 int  exp
    CODE:
        RETVAL = Perl_ldexp(x, exp);
    OUTPUT:
        RETVAL

which replaces this section of POSIX.xs in the 5.29.2 source:

NV
ldexp(x,exp)
 NV  x
 int  exp

Cheers,
Rob

On Sat, Sep 22, 2018 at 12:27 AM sisyphus <sisyphus359@gmail.com> wrote:

> Hi,
>
> The build fails during the "make" stage thusly:
>
> POSIX.o:POSIX.c:(.text+0x5ee2): undefined reference to `Perl_ldexp'
>
> It's essentially the same failure on both 32-bit and 64-bit builds, but
> it's only the "long double" builds that are affected.
> There was no such problem with perl-5.29.2.
>
> Looking at the git log, the only reference to "ldexp" that I could find
> (for the relevant period) was:
>
> ##############
>
> commit e6081c0ea8a779f5fdd429d2dfb48bf094bb92c4
>
> Author: Tony Cook <tony@develop-help.com>
>
> Date: Wed Sep 12 11:09:52 2018 +1000
>
> (perl #133510) use quadmath versions of log10, ldexp and signbit
>
> With -Dquadmath C++ builds, the calls to log10() and ldexp() would
>
> cause ambiguous overloaded function errors, since all of log10(float),
>
> log10(double) and log10(long double) were canidates for a
>
> log10(__float128) call. Similarly for ldexp().
>
> signbit() had a different problem, two of the tests in ext/POSIX/t/math.t
>
> failed with the default signbit() macro, presumably because the
>
> __float128 was being converted to a long double, since the macro in
>
> math.h didn't special case for __float128.
> ##############
>
> Cheers,
> Rob
>
>
>

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