The gdtoa code here is based on David M. Gay's original gdtoa source at http://www.netlib.org/fp/ from April 20, 2009. The major changes between the original source and the mingw port here include: * IBM, CRAY and VAX code removed. * KR_headers, ANSI, Void and Char ifdefs are removed. * gdtoa symbols are prepended with "__". * g_xfmt() uses __fpclassifyl() instead of interpreting the flags bit-wise. * lo0bits() and hi0bits() of misc.c replaced by wrappers to gcc's __builtin_clz() * The double/ulong union renamed from U to dbl_union (grep'ped better..) * A few compiler warning fixes here and there. * A few other insignificant changes (if any..) MinGW specific compile-time definitions are at the top of gdtoaimp.h and gdtoa.h headers.