Dmitri Hrybenko 9177107940 stdlib/Hashing: move the hash seed variable to C++ code to avoid ...

dispatch_once calls on every load from it

Performance improvements, as reported by the perf testing buildbot:

Histogram       -18.81%
TwoSum          -17.42%
RGBHistogram    -9.65%

Regressions:

InsertionSort                5.59%
ArrayOfRef                   3.99%
SwiftStructuresInsertionSort 5.29%
PrimeNum                     6.09%

These regressions are bogus.  The tests that "regressed" don't do any
hashing at all.

Swift SVN r23995

2014-12-17 23:45:29 +00:00

1.3 KiB

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