MPS: optimized build

["Gerd Möllmann" <gerd.moellmann@gmail.com>]

I'm using an optimized build of scratch/igc today, in an attempt to
somehow distract myself from my sciatica. And I thought, why not write
someting about what I'm seeing. Who knows for what it's good.

This is of course macOS 14, Apple silicon.

So, anecdotal observations:

Survival time so far 1 hour, no crash. "Normal" usage for me, packages
I use and so on... YMMV.

I find build times surprising. 1:08 minutes with MPS (the non-debug
version), 1:18 without MPS. I would have expected the opposite, and with
a large difference. So much to intuition when it comes to performance,
but that only in passing.

Interactive use is, let me say, agreeable? :-)

I still see pauses sometimes but I would say these are not caused by
GC. I can see GC running BTW, with garbage-collection-messages set to
t and I've changed igc.c to write the messages to *Messages* to have a
better overview. So, synchronous process interaction, JSON parsing and
what else lead to some small pauses. No surprise.

In general, but I guess the wish is the father of the thought as we say
here, Emacs seems to be, hm, snappier? Consult, vertico, corfu, ...
completions, even typing text maybe?

Would be interesting to hear from others how they perceive it...