When calling _getOwner at this point we know that it is a native array.
This simplifies the SIL code for assigning a class array element (a[i] = x).
Swift SVN r27124
We define two new library functions _knownForceBridgeFromObjectiveC/_knownConditionallyBridgeFromObjectiveC, similar to _forceBridgeFromObjectiveC/_conditionallyBridgeFromObjectiveC. The main difference is that they require their arguments to conform to _BridgedToObjectiveC and _BridgedToObjectiveC. _ObjectiveCType accordingly. With this change, it is now possible to invoke the _BridgedToObjectiveC._forceBridgeFromObjectiveC witness directly, without going via the inefficient swift_bridgeNonVerbatimFromObjectiveC.
So now, for a cast O -> S, if it can be statically proven that an ObjC type O is bridgeable to a Swift type S implementing the _BridgedToObjectiveC protocol (i.e. O is the class (or its subclass) defined by the S._ObjectiveCType alias), we can generate a code to invoke the newly defined library function _knownForceBridgeFromObjectiveC/_knownConditionallyBridgeFromObjectiveC instead of _forceBridgeFromObjectiveC/_conditionallyBridgeFromObjectiveC.
After inlining, this will end-up invoking S._forceBridgeFromObjectiveC directly instead of invoking a more general, but less effective swift_bridgeNonVerbatimFromObjectiveC, which always performs conformance checks at runtime, even if conformances are known statically. As a result, no conformance checks are performed at run-time if conformances are known statically.
The client code making use of these new APIs and the tests are coming in the subsequent commits.
The naming of the two new helper library functions was discussed with Dmitri.
This is part of the bridging casts optimization effort. And it is specifically useful for e.g. rdar://19081345.
Swift SVN r27100
Retire the old components now that the new ones have passed API review.
<rdar://20406937> covers the migration fallout of this change.
Swift SVN r27092
The new mirror design passed our API review and blocking bugs have been
fixed/worked-around, so integrating it into the core standard library.
Swift SVN r27082
Retire the old components now that the new ones have passed API review.
<rdar://20406937> covers the migration fallout of this change.
Swift SVN r27081
Simplify the observation evaluation in the ErrorType race test by using evaluateObservationsAllEqual, and run the test for real. Apparently round-trip NSString and NSDictionary bridging doesn't produce a stable object, so use valueForKey as a hack to sidestep bridging so we can verify that the identities of the bridged domain and code aren't racy.
Swift SVN r27003
Atomically initialize and load the NSError bridging fields within an ErrorType box so that we do the right thing when two threads concurrently coerce the box to NSError.
Swift SVN r26996
If the NSError part of the box hasn't been initialized yet, fill it in with the domain and code of the contained value. This will allow us to efficiently turn ErrorType values into NSErrors, either for bridging or for coercion purposes.
Swift SVN r26958
Changes compared to the original version:
I fixed the 2 bugs and added a test for the so far undetected missing range check bug.
To keep the SIL simple (4 basic blocks for arr[x]) I extracted the slow path for getElement into a
non-inlinable function.
On the other hand I inlined _typeCheck into the slow-path function.
This speeds up NSArray accesses because now only a single objectAtIndex is required for both
type checking and element retrieving.
Update on performance: DeltaBlue is now only 12% better (and not 25%). I suspect this is because
now Arnold's tail duplication cannot detect the ObjC call in the slow path.
Swift SVN r26935
The performance regression that occurred when ++ and -- were added as
requirements to the Index protocols was due to the fact that it caused a
dubious hack of mine to be bypassed: when treated as indices, integer
types are incremented and decremented without overflow checking. While
technically justifiable (see the r20576 commit message), this makes the
standard library extremely fragile and makes successor() and
predecessor() mathematically unsafe. We really should see what the
optimizer team can do to make that hack unnecessary.
In the meantime, instead of dispatching through ++ and --, use a
special, defaulted _[successor|predecessor]InPlace() method to give
indices their own, customizable in-place inc/dec-rement path.
Swift SVN r26926
Retire the old components now that the new ones have passed API review.
<rdar://20406937> covers the migration fallout of this change.
Swift SVN r26904
Previously some parts of the compiler referred to them as "fields",
and most referred to them as "elements". Use the more generic 'elements'
nomenclature because that's what we refer to other things in the compiler
(e.g. the elements of a bracestmt).
At the same time, make the API better by providing "getElement" consistently
and using it, instead of getElements()[i].
NFC.
Swift SVN r26894
