bug#18752: 24.3.94; Why is Cygwin Emacs 2x quicker than Windows Emacs?

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Dani Moncayo <dmoncayo@gmail.com>,  18752@debbugs.gnu.org,  
> fni-news@pirilampo.org
> Date: Sat, 18 Oct 2014 15:25:15 -0400
> 
> I still constantly get "variable optimized away" messages in GDB.

Nothing can be done about this, given the complexity of DWARF and
compiler/debugger bugs in implementing its dark corners.

The problem with debugging -O2 code is that you cannot trust
backtraces, and cannot set breakpoints and be sure they will break.
This doesn't happen with -Og.