See the README one level up about where to find the reference manual
for the stm32f4 and schematics for the board.

Just having some fun.  Curious to know how the hardware fpu compared
to TestFloat.  Extracted only the add function which is easy/boring
and it looks good.  A NaN is not a fixed bit pattern so not surprising
they dont match.  I guess I could have said if this is a nan and that
is a nan then pass, instead I said if TestFloat says nan, continue;

llvm likes to throw memcpy()'s into code with structures where gcc
doesnt.  Very ugly memcpy() implementation, which probably hurts llvm's
overall slowfloat performance.