Mingw FPU init not Windows compatible.
Mingw initializes the FPU top 80 bit precision instead of MSVC's 53 bits (which is the standard). I suggest ghc linking on Windows should be changed to that it uses 53 bits instead. This will make programs more Windows compatible (and possibly faster).
Here's a comment from Mingw's Float.h:
/*
MSVCRT.dll _fpreset initializes the control register to 0x27f,
the status register to zero and the tag word to 0FFFFh.
This differs from asm instruction finit/fninit which set control
word to 0x37f (64 bit mantissa precison rather than 53 bit).
By default, the mingw version of _fpreset sets fp control as
per fninit. To use the MSVCRT.dll _fpreset, include CRT_fp8.o when
building your application.
*/