[Bug c/120937] floating-point arithmetic can result zero with incorrect sign

[madams846 at hotmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120937

--- Comment #4 from Marc Adams <madams846 at hotmail dot com> ---
Sorry, you are correct and I am wrong.  The result is subnormal negative and
rounds to -0.  Thanks for your help.