On Mon, 2008-02-04 at 15:48 +0000, Ian Rogers wrote: > Hi, > > xalan performs 1.4 million char array clones per iteration of the normal > size DaCapo benchmark. All of the character array clones are coming from > java.lang.String. The attached patch changes the use of char[].clone > (which maps to java.lang.Object.clone) to a helper method that allocates > the character array and then array copies from the source to the new > array. On the Jikes RVM I get the following performance results from 10 > iterations of DaCapo using the large data set size: > > current java.lang.String using char[].clone: > run 1: 99157ms > run 2: 98700ms > run 3: 97927ms > > patched java.lang.String using the helper routine: > run 1: 97710ms > run 2: 97406ms > run 3: 96762ms > > The speed up is between 0.22% and 1.2%. Do people think using the helper > is a sensible change?
Hi Ian! Does the speedup come from the ability to inline the help method, while the clone() cannot? - twisti
