Re: [Sbcl-devel] Re: SBCL compile performance (was Re: renaming)]

[Christophe R. <cs...@ca...>]

On Fri, Mar 08, 2002 at 11:47:11AM -0500, Raymond Toy wrote:

> Of course, SBCL doesn't really have this problem because it can
> build itself easily, right?  :-)

Heh. We're working on it. :)

And actually the opportunity to reply under this thread is too
tempting, despite the fact that it's only tangentially related...
since clisp 2.28 has been released, I took the opportunity to see what
would happen when I tried compiling it; as it happens, it dies in
aliencomp because of the non-BOA-constructor for alien-type and
local-alien-info -- it warns about treating bits and type respectively
as specials. I don't know how to fix this; there's one call to
make-local-alien-info which would need fixing, but I couldn't actually
find _any_ to make-alien-type, which causes all sorts of alarm bells
to ring as it usually means I'm missing something :)

That said, and tying this into the thread of compiler performance, I
have implemented yet another compiler pessimization (possibly). This
one, however, might be more welcome than most, as I have ripped out
the evil code from hell in src/compiler/assem.lisp. With the attached
patch (incidentally also including my fix to the thing I whined about
earlier today) sbcl builds (in CMUCL), passes tests, and is in the
process of building itself again... of course, I don't actually claim
to understand fully what the magical symbol-macrolet stuff was meant
to be doing, and I have also removed at least one layer of protection,
so I would like to make it clear that this patch also causes alarm
bells to start ringing.

I would like to submit this, but please test it to see (a) if it works
and (b) if the performance degradation (if any) is acceptable. I
haven't measured it, but it doesn't look like it's noticeably
increasing the time this (second) compilation is taking, but this is
very subjective as I am simultaneously working on some relativistic
calculations...

Cheers,

Christophe
-- 
Jesus College, Cambridge, CB5 8BL                           +44 1223 510 299
http://www-jcsu.jesus.cam.ac.uk/~csr21/                  (defun pling-dollar 
(str schar arg) (first (last +))) (make-dispatch-macro-character #\! t)
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