Re: (select-window nil) crash with gcc-8.2.0

[Eli Zaretskii]

> From: Paul Eggert <address@hidden>
> Date: Sun, 7 Apr 2019 11:33:22 -0700
> Cc: address@hidden
> 
> and that last movq dereferences the window pointer in %rbx before the result 
> of 
> WINDOWP is checked to verify that the argument (originally in %rdi, now in 
> %rbx) 
> is indeed a window.
> 
> Could you file a GCC bug report for this? And in the meantime, I wouldn't use 
> -Os.

Thanks.  So just -O2 produces correct code?  Because I think GCC 8 is
quite popular, and the default build uses -O2.  If -O2 is prone to
something similar, maybe we should make some changes in the code to
avoid that.