Subject: Re: bug#32405: [PATCH] Turn misc objects into pseudovectors

From: Andy Moreton <[email-masked]>
Date: Thu, 09 Aug 2018 18:23:05 +0100

On Wed 08 Aug 2018, Paul Eggert wrote:

> Eliminate the category of miscellaneous objects, and turn all
> such objects into pseudovectors.  The immediate motivation
> for this change is to free up an enum Lisp_Type tag value, a
> scarce resource that can be better used elsewhere.  However,
> this change is worthwhile in its own right, as it improves
> performance slightly on my platform, 0.3% faster for 'make
> compile-always' on Fedora 28, and it simplifies the garbage
> collector and interpreter.

If the patch makes the interpreter simpler that sounds worthwhile, but
are you sure there is a meaningful performance difference ? 0.3% sounds
lost in the noise. What is the time/space impact on 32bit bit platforms ?

Integration of this patch and the bignum feature branch into master may
both need some time to stabilize. Please discuss with Eli and Tom to
agree which is merged first, and allow time for master to reach a stable
state before the second of them is merged.

    AndyM