On 12/17/2014 7:56 AM, navin p wrote: > 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. > > gcc supports 80--bit long double, but printf format %.18g casts to 64-bit double prior to formatting, even if you link a printf with long double support (which the Microsoft one lacks). As you hinted, you would also need to over-ride the Windows X64 run-time default of 53-bit precision mode, but this will apply only to x87 code (such as explicit long double), while the default for double is SSE2 on X64. > -- > Tim Prince
