Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!gatech!ncsuvx!ece-csc!ncrcae!sauron!campbell From: campbell@sauron.Columbia.NCR.COM (Mark Campbell) Newsgroups: comp.sys.intel Subject: I80386 String Operations Message-ID: <917@sauron.Columbia.NCR.COM> Date: Mon, 20-Jul-87 09:59:56 EDT Article-I.D.: sauron.917 Posted: Mon Jul 20 09:59:56 1987 Date-Received: Tue, 21-Jul-87 04:57:49 EDT Organization: Advanced Systems Development, NCR Corp., Columbia, SC Lines: 21 Keywords: Performance, I80386, Strings, Characters Could someone out there explain or point to literature explaining the I80386 string manipulation operations? What I'm wondering is why the I80386 string operations are so efficient. For example, the sequence* slodb scab in a string compare loop appears to be much faster than the corresponding MC68020 load and compare instructions, even if the MC68020 can access memory more quickly in all (byte, word, and longword) normal cases. The only theory I have is that these instructions are somehow using the memory bus more efficiently than you would think, given that they are byte operations. Thanks. * INTERACTIVE I80386 assembler -- Mark Campbell {}!ncsu!ncrcae!sauron!campbell