Program that segfaults with-Ofast

[Christer Solskogen <christer.solskogen@xxxxxxxxx>]

... but works fine with O2.
How can I debug that?

It does not with happen on 6.3.0, but it does with 7.2.0. Or.. say in 
another way: It works in Raspbian, but not in Arch Linux ARM. And it's 
quite easy to make the assumption that the compiler is to blame (it 
might not be!)

So the question is... How can I debug it?
Oh, it also segfaults with O3.


--
chs