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Revision 889145


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Author: jessewilson
Date: Thu Dec 10 08:56:29 2009 UTC (14 years, 4 months ago)
Changed paths: 1
Log Message:
Changing AbstractList's iterator to track elements remaining rather than elements already returned.

On DRLVM, this results in a modest 10% runtime improvement in iteration. When I used -Xbootclasspath to run the current and new code on hotspot, the improvement was more pronounced. Runtimes are below; the benchmark results are below.
http://code.google.com/p/caliper/source/browse/trunk/test/com/google/caliper/examples/ListIterationBenchmarkSuite.java?spec=svn17&r=17

length       vm    ns logarithmic runtime
     0       RI    20 |||||||||||
     0  current    16 ||||||||||
     0      new    14 ||||||||||
    10       RI    63 ||||||||||||||||
    10  current    82 |||||||||||||||||
    10      new    45 ||||||||||||||
   100       RI   393 |||||||||||||||||||||||
   100  current   672 |||||||||||||||||||||||||
   100      new   243 |||||||||||||||||||||
  1000       RI  1191 |||||||||||||||||||||||||||
  1000  current  2153 ||||||||||||||||||||||||||||||
  1000      new  1294 ||||||||||||||||||||||||||||


Changed paths

Path Details
Directoryharmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/util/AbstractList.java modified , text changed

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