MinGW and MSVCRT Conflict Causes Floating-Point Value Corruption

jones_supa writes: If you are working on a C++ program where you need very accurate floating point numbers, you might have decided to use long double data type for the extra precision. After a few calculations, you happen to print your number. To your shock, instead of the number being 123.456789, it is printed out as -6.518427 × 10^264 (or 2.745563 depending on your computer). This is actually a bug in some versions of MinGW g++ 4.8.1 (MinGW is a port of GNU programming tools for Windows). Microsoft’s C++ runtime library reserves 80 bits for double and long double. When MinGW uses the Microsoft DLL to print out the value, the number is interpreted as using only 64 bits. This discrepancy causes garbage results to be output.

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