On 11/3/2010 3:08 AM, Li Li wrote:
hi all we found function call in java will cost much time. e.g replacing Math.min with a<b?a:b will make it faster. Another example is lessThan in PriorityQueue when use Collector to gather top K documents. Yes, use function and subclass make it easy to maintain and extend. in C/C++, we can use inline fuction to optimize. What about java? I see many codes in lucene also inline many codes mannully. such as implmented hash map in processDocument, SegmentTermDocs.read "// manually inlined call to next() for speed". Is there any compiler option for inline in java? Or we may hardcode something for time consuming tasks--------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
The JVM does optimizations like this with its JIT compiler, which operates at runtime and optimizes "hot spots" in the execution of the application. Some resources you might want to look at:
http://en.wikipedia.org/wiki/Just-in-time_compilation http://java.sun.com/developer/onlineTraining/Programming/JDCBook/perf2.html http://java.sys-con.com/node/1118894 Thanks, Eddie --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
