Hi Ivan,

On 2018-02-03 02:14, Ivan Gerasimov wrote:
Would you please help review the fix?

BUGURL: https://bugs.openjdk.java.net/browse/JDK-8196740
WEBREV: http://cr.openjdk.java.net/~igerasim/8196740/00/webrev/

yes, an obvious error in hindsight!



I suspect that this version may even work a tiny bit faster, as we perform less comparisons in a common case.

Counter-intuitively it actually seems the compiler generates faster code in the end when keeping the
value >= 0 test around.

Your version:

Benchmark Mode  Cnt     Score   Error  Units
UUIDBenchmark.benchmarkUUIDFromString avgt    4     0.326 ± 0.017  us/op
UUIDBenchmark.benchmarkUUIDFromString:branches avgt        289.750           #/op UUIDBenchmark.benchmarkUUIDFromString:cycles avgt       1044.087           #/op

With:
        int value = DIGITS[ch];
        return (value >= 0 && value < radix && radix >= Character.MIN_RADIX
                && radix <= Character.MAX_RADIX) ? value : -1;

Benchmark Mode  Cnt     Score   Error  Units
UUIDBenchmark.benchmarkUUIDFromString avgt    4     0.310 ± 0.018  us/op
UUIDBenchmark.benchmarkUUIDFromString:branches avgt        256.489           #/op UUIDBenchmark.benchmarkUUIDFromString:cycles avgt        988.998           #/op

/Claes

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