[ https://issues.apache.org/jira/browse/MATH-650?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13208820#comment-13208820 ]
Gilles commented on MATH-650: ----------------------------- I may be mistaken but I think that cloning the arrays is useless: "clone()" protects the arrays in {{FastMathLiteralArrays}} but not the arrays that are actually used. Since the arrays are "private", only a bug local to {{FastMath}} can mess with them. And, if there is a bug, it will have the same effect whether "clone()" is called or not. > FastMath has static code which slows the first access to FastMath > ----------------------------------------------------------------- > > Key: MATH-650 > URL: https://issues.apache.org/jira/browse/MATH-650 > Project: Commons Math > Issue Type: Improvement > Affects Versions: Nightly Builds > Environment: Android 2.3 (Dalvik VM with JIT) > Reporter: Alexis Robert > Priority: Minor > Fix For: 3.0 > > Attachments: FastMathLoadCheck.java, LucTestPerformance.java > > > Working on an Android application using Orekit, I've discovered that a simple > FastMath.floor() takes about 4 to 5 secs on a 1GHz Nexus One phone (only the > first time it's called). I've launched the Android profiling tool (traceview) > and the problem seems to be linked with the static portion of FastMath code > named "// Initialize tables" > The timing resulted in : > - FastMath.slowexp (40.8%) > - FastMath.expint (39.2%) > \- FastMath.quadmult() (95.6% of expint) > - FastMath.slowlog (18.2%) > Hoping that would help > Thanks! > Alexis Robert -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira