Re: My Emacs unicode 2 crash again when I do some *Replace String (M-%)*, I give the debug informations under gdb in the attachments.

[Stefan Monnier]

> I disagree.  -O1 selects optimizations based on how expensive they are
> at compile time, not on how badly they disrupt debugging.

Really?  Says who?

I don't know if there's an official definition of what -O should be, but
AFAICT all it says is "please optimize this" in a very generic sense.
I.e. in a sense which implies that the user doesn't want to waste time
thinking about details such as which specific optimizations to enable and
which to disable.  It should "just work", so it should be as good as
possible while staying conservative (i.e. do not enable passes which have
a significant risk of resulting in slower code, or which may alter the
semantics of the code, or which may result in odd behavior in the debugger).
I would probably also include a notion of "avoid optimzation passes which
can take too much time (e.g. quadratic complexity or worse)", but it's
definitely not at the top of my list of requirements for the semantics of
"-O".


        Stefan