mingw-64 80 bit precision for doubles works

[navin p]

Hello,
   Visual Studio 2010 cannot build x64 executables with 80 bits
extended precision for doubles. Atleast it has been removed in Visual
Studio 2013 saying not supported on x64 and ARM platforms.

_MCW_PC (Precision control)

(Not supported on ARM or x64 platforms.)


  How can gcc/mingw-64 build x64 executables with double precision set
to 80 bits?

I get rounding errors when i do %.18g for doubles on windows but
Visual Studio truncates the last digits for 2^61 and all.


Regards,
Navin