Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!usc!zaphod.mps.ohio-state.edu!think.com!mintaka!spdcc!ima!iecc!compilers-sender From: hankd@ecn.purdue.edu (Hank Dietz) Newsgroups: comp.compilers Subject: Re: Recursive Descent Parsers and YACC Summary: Speed about 2-3x LL vs. LR Keywords: parse, yacc, design, question Message-ID: <9011171759.AA09103@dynamo.ecn.purdue.edu> Date: 17 Nov 90 17:59:15 GMT References: Sender: compilers-sender@iecc.cambridge.ma.us Reply-To: hankd@ecn.purdue.edu (Hank Dietz) Organization: Purdue University Engineering Computer Network Lines: 15 Approved: compilers@iecc.cambridge.ma.us In article melling@psuvax1.cs.psu.edu (Michael D Mellinger) writes: >Can someone give me an estimate on how much faster parsing can be made by >writing a recursive-descent parser instead of using Yacc and Lex? ... PCCTS (the Purdue Compiler-Construction Tool Set) builds LL(k) parsers which average about 2-3x as fast as YACC's parsers. The primary difference between them is that LL stack management can be implemented directly with machine instructions on most machines, whereas LR stack handling requires an interpreter... hence the 2-3x difference (for example, it was about 2x for Pascal). -hankd -- Send compilers articles to compilers@iecc.cambridge.ma.us or {ima | spdcc | world}!iecc!compilers. Meta-mail to compilers-request.