Path: utzoo!yunexus!geac!syntron!jtsv16!uunet!lll-winken!lll-tis!ames!ncar!boulder!sunybcs!rutgers!mcnc!duke!romeo!mps From: mps@romeo.cs.duke.edu (Michael P. Smith) Newsgroups: comp.lang.lisp,comp.sys.ti.explorer Subject: Tail Recursion Optimization Keywords: TI CL, Sun CL Message-ID: <12198@duke.cs.duke.edu> Date: 12 Aug 88 03:04:05 GMT Article-I.D.: duke.12198 Sender: news@duke.cs.duke.edu Reply-To: mps@duke.UUCP () Distribution: na Organization: Duke University CS Dept.; Durham, NC Lines: 13 I made a discovery recently I found shocking: TI Common Lisp on the Explorer does not properly treat tail recursion. In fact, the tail-recursive factorial ran out of push-down list (control stack) before the naive-recursive version did! When I compiled and disassembled versions of the fibonacci function, the tail-recursive and do-loop versions were virtually indistinguishable in Sun Common Lisp, but the compiled and disassembled tail-recursive version under TICL still had the recursive call. Can anyone explain the reason for this? Are there other lisp compilers out there that do not treat tail recursion iteratively? Michael P. Smith