Subject: Re: What is expensive about consing
From: (Rob Warnock)
Date: Fri, 12 Sep 2008 02:02:41 -0500
Newsgroups: comp.lang.lisp
Message-ID: <>
Scott Burson  <> wrote:
| (Rob Warnock) wrote:
| > With this change, (REDUCE #'+ NUMBER-LIST :MAX-ARITY T) could be
| > implemented *VERY* efficiently, and could even be coded by the
| > compiler to use whatever SIMD or vector (e.g., SSE2/3) instructions
| > were available on the platform.
| Why can't (REDUCE #'+ NUMBER-LIST) be compiled just as efficiently now?

Hmmm... You're right, it could. And, in fact, could also be for
any function whose signature is lexically apparent to the compiler.

But :MAX-ARGS might still be useful if the REDUCE call were inside
a separately-compiled routine that accepted a function argument...


Rob Warnock			<>
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