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Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!mcsun!ukc!edcastle!aiai!jeff
From: jeff@aiai.ed.ac.uk (Jeff Dalton)
Newsgroups: comp.lang.scheme,comp.lang.lisp
Subject: Re: in defense of C
Message-ID: <1942@skye.ed.ac.uk>
Date: 6 Mar 90 19:36:27 GMT
References: <1903@skye.ed.ac.uk> <14112@cbnewsc.ATT.COM>
Reply-To: jeff@aiai.UUCP (Jeff Dalton)
Organization: AIAI, University of Edinburgh, Scotland
Lines: 18

In article <14112@cbnewsc.ATT.COM> lgm@cbnewsc.ATT.COM (lawrence.g.mayka,ihp,) writes:
 >One of the most important quality measures of a Common Lisp
 >compiler is the level of safety it supports without an undue
 >sacrifice in execution speed.  The better CL implementations score
 >quite highly on this scale, especially on newer processor
 >architectures such as SPARC.  For example, the better compilers
 >indeed ensure that CAR and CDR are only applied to lists, without
 >a loss of execution speed and even though a CL implementation must
 >permit one to apply CAR and CDR to the symbol NIL.

You say this as if it were typical of better compilers on machines
other than SPARCs, such as, maybe, 68020s.  Can they really have safe
CARs and CDRs, without loss of speed, on a 68020?  If so, I would
expect that safety to remain even if I set saftey=0, but that doesn't
seem to be what happens.  Moreover, how many of the SPARC compilers
can do this?  I suspect it's only one or two of them.

-- Jeff