[Bug c/64442] -O1 modify output of a simple computation with rounding

[colin.pitrat+gcc at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64442

--- Comment #2 from Colin Pitrat <colin.pitrat+gcc at gmail dot com> ---
Yes I'm building on i686.

But I thought -O1 and -O2 were safe optimization that weren't supposed to
change the behaviour.

Moreover, I'm surprised that providing the list of -f flags -O1 is supposed to
enable doesn't allow me to reproduce the issue.