LGTM, just a few comments.
http://gwt-code-reviews.appspot.com/572801/diff/9001/10005 File dev/core/super/com/google/gwt/lang/LongLibBase.java (right): http://gwt-code-reviews.appspot.com/572801/diff/9001/10005#newcode55 dev/core/super/com/google/gwt/lang/LongLibBase.java:55: protected static boolean RUN_IN_JVM = false; This should be documented -- if it does what I think it does, which is to allow you to debug this in the JVM during development, then this should be final. http://gwt-code-reviews.appspot.com/572801/diff/9001/10005#newcode414 dev/core/super/com/google/gwt/lang/LongLibBase.java:414: private static int nlz(int x) { Replace calls to this method with a call to Integer.numberOfLeadingZeros(x). If this algorithm is faster, the method in Integer should be updated. http://gwt-code-reviews.appspot.com/572801/diff/9001/10005#newcode459 dev/core/super/com/google/gwt/lang/LongLibBase.java:459: private static int powerOfTwo(int x) { Is this guaranteed to be called with a power of 2? x & -x will give you the lowest bit set -- not sure if there are any edge cases or if this is faster, but you might consider: // if not a power of two, return (check for 0 if not non-zero) if (x != x & -x) { return -1; } return Integer.numberOfTrailingZeros(x); Again, if numberOfTrailingZeros isn't fast enough, update it with a better algorithm. http://gwt-code-reviews.appspot.com/572801/show -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
