GNU bug report logs - #24102
Use guile variable objects as SRFI-111 boxes.

Previous Next

Full log

View this message in rfc822 format

From: Andy Wingo <wingo <at> pobox.com>
To: Mark H Weaver <mhw <at> netris.org>
Cc: 24102 <at> debbugs.gnu.org, Glenn Michaels <gmichaels <at> Safe-mail.net>
Subject: bug#24102: Use guile variable objects as SRFI-111 boxes.
Date: Wed, 31 Aug 2016 11:03:05 +0200

On Thu 18 Aug 2016 18:14, Mark H Weaver <mhw <at> netris.org> writes:

> As I wrote above, the current guile compiler can already do this kind of
> type inference, although it does not currently do this for boxes.
> we can already anticipate having native code generation in the
> next couple of years, and we must keep boxes semantically simple so that
> our future compiler will be able to generate good code for this very
> important fundamental type.

For what it's worth, I don't see the optimization argument as weighing
very heavily on this discussion.  I would rather have fewer fundamental
data types rather than more, in the next two years or so.  I see the
mid-term result here being that SRFI-111 boxes are much slower than
variables.

The highest performance compilation tier we can imagine would include
adaptive optimization, and when it runs you can know that the variables
that a bit of code uses are bound or not.  Also in that case we can
reasonably make any call to variable-unset! deoptimize any code that
uses variables, forcing it to reoptimize later.  Since variable-unset!
is quite rare this is no big deal I think.

Andy

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.