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

From: Eli Zaretskii <[email-masked]>
Date: Sat, 18 Oct 2014 22:34:15 +0300

> From: Stefan Monnier <[email-masked]>
> Cc: Dani Moncayo <[email-masked]>,  [email-masked],  [email-masked]
> 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.