This function mixes the bits in the hash value, which improves Dictionary
performance for keys with bad hashes.
PrecommitBenchmark changes with greater than 7% difference:
``````````Dictionary2`,```1456.00`,```1508.00`,```1502.00`,````624.00`,````607.00`,````592.00`,`864.00`,``145.9%
``````````Dictionary3`,```1379.00`,```1439.00`,```1408.00`,````585.00`,````567.00`,````552.00`,`827.00`,``149.8%
````````````Histogram`,````850.00`,````849.00`,````851.00`,```1053.00`,```1049.00`,```1048.00`,`199.00`,``-19.0%
````````````````Prims`,```1999.00`,```2005.00`,```2018.00`,```1734.00`,```1689.00`,```1701.00`,`310.00`,```18.4%
``````````StrSplitter`,```2365.00`,```2334.00`,```2316.00`,```1979.00`,```1997.00`,```2000.00`,`337.00`,```17.0%
```````````````TwoSum`,```1551.00`,```1568.00`,```1556.00`,```1771.00`,```1741.00`,```1716.00`,`165.00`,```-9.6%
Regressions are in benchmarks that use `Int` as dictionary key: we are just
doing more work than previously (hashing an `Int` was an identity function).
rdar://17962402
Swift SVN r21142
The test harness now can recover after test crashes, allowing:
- check for crashes themselves (without reporting them to the Python lit driver,
which is about 10x slower -- even if CrashTracer is disabled);
- recover from unexpected test crashes and run the rest of the tests;
- this lays the groundwork for assertions that end the test execution, but
allow the rest of the tests to run (rdar://17906801).
Note that we don't spawn a fresh process for every test. We create a child
process and reuse it until it crashes.
Swift SVN r21090
1. Remove incorrect @readonly semantics on two functions.
2. Overload toString for some of the popular types and add readonly semantics so that we can optimize them away.
Swift SVN r21045
Symmetry with what we did for Arrays says that Strings shoudl only
concatenate to Strings using "+". We have append() for adding single
characters.
Swift SVN r20997
_preconditionFailure()s. Some of these checks are clearly redundant (for
example, the check of array subscript), but since we have no tests for
these traps (and reflection is not fast in general), I prefer to keep this
transformation as straightforward as possible.
Swift SVN r20971
Previously, we were checking whether a particular argument could be
dynamic-casted to a Float or Double (via as?). However, now that
dynamic casting considers bridging, this would try to pass an NSNumber
in a floating-point register, and hilarity ensues. Fixes the
regression I introduced with object-to-value bridging in r20963.
Swift SVN r20967
The _forceBridgeFromObjectiveC and _conditionallyBridgeFromObjectiveC
requirements of the _ObjectiveCBridgeable protocol previously returned
Self and Self?, respectively, where 'Self' is the value type that is
bridged. This use of returns is fairly hostile to the idea of calling
the witnesses for these requirements from the C++ part of the runtime,
leading to "interesting" tricks with OpaqueExistentialContainer that
made it hard to use these witnesses within the dynamic casting
infrastructure.
Replace the returns with inout Self? parameters, which are far easier
to deal with in the C++ part of the runtime. Despite the churn because
we're changing the _ObjectiveCBridgeable protocol, this is NFC.
Swift SVN r20934
As I was reducing a test case for a typechecker bug, I ended up
commenting out important test code in the regression suite. This
restores it (and makes it work).
Swift SVN r20925
