[Bug middle-end/576] gcc performs invalid optimization with float operations when different rounding mode.

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=576

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Vincent Lefèvre from comment #5)
> The -frounding-math option should solve the issue on this particular
> example. But on my machine, ld gives an "undefined reference to `_up'" error.

That is because the code is GNU C90 and not C++ .