[ http://issues.apache.org/jira/browse/LUCENE-639?page=comments#action_12425333 ] Yonik Seeley commented on LUCENE-639: -------------------------------------
The XOR algorithm is a clever idea, but based on some quick tests of my own, it seems slower than my "combine on exit" for what I would guess would be an important case of a mix of 1 and 2 byte vints. for random numbers less than 128, the algorithms tied (not surprising). for random numbers less than 200 (a mix of 1 and 2 byte vints): 13% slower on AMD Opteron, Java 1.5.0_07 -server -Xbatch 15% slower on P4, Java 6 beta2 -server -Xbatch > [PATCH] Slight performance improvement for readVInt() of IndexInput > ------------------------------------------------------------------- > > Key: LUCENE-639 > URL: http://issues.apache.org/jira/browse/LUCENE-639 > Project: Lucene - Java > Issue Type: Improvement > Components: Index > Affects Versions: 2.0.0 > Reporter: Johan Stuyts > Priority: Minor > Attachments: Lucene2ReadVIntPerformance.patch, readVInt performance > results.pdf, ReadVIntPerformanceMain.java > > > By unrolling the loop in readVInt() I was able to get a slight, about 1.8 %, > performance improvement for this method. The test program invoked the method > over 17 million times on each run. > I ran the performance tests on: > - Windows XP Pro SP2 > - Sun JDK 1.5.0_07 > - YourKit 5.5.4 > - Lucene trunk -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
