The runtime and stubs are built for ALL targets, not specific ones. This allows
us to configure when cross-compiling to Windows again. Collapse the dual
addition of the swiftRuntime into a single build. This unifies the runtime
build for the apple and non-Apple SDKs. The difference here was the ObjC
interop sources. In order to deal with that unification add a CPP macro to
indicate whether the interop sources should be included or not.
The general rule here is that something needs to be SWIFT_CC(swift)
if it's just declared in Swift code using _silgen_name, as opposed to
importing something via a header.
Of course, SWIFT_CC(swift) expands to nothing by default for now, and
I haven't made an effort yet to add the indirect-result / context
parameter ABI attributes. This is just a best-effort first pass.
I also took the opportunity to shift a few files to just implement
their shims header and to demote a few things to be private stdlib
interfaces.
Use it for hashing and comparison.
During String's hashValue and comparison function we create a
_NSContiguousString instance to call Foundation's hash/compare function. This is
expensive because we have allocate and deallocate a short lived object on the
heap (and deallocation for Swift objects is expensive). Instead help the
optimizer to allocate this object on the stack.
Introduces two functions on the internal _NSContiguousString:
_unsafeWithNotEscapedSelfPointer and _unsafeWithNotEscapedSelfPointerPair that
pass the _NSContiguousString instance as an opaque pointer to their closure
argument. Usage of these functions asserts that the closure will not escape
objects transitively reachable from the opaque pointer.
We then use those functions to call into the runtime to call foundation
functions on the passed strings. The optimizer can promote the strings to the
stack because of the assertion this API makes.
let lhsStr = _NSContiguousString(self._core) // will be promoted to the stack.
let rhsStr = _NSContiguousString(rhs._core) // will be promoted to the stack.
let res = lhsStr._unsafeWithNotEscapedSelfPointerPair(rhsStr) {
return _stdlib_compareNSStringDeterministicUnicodeCollationPointer($0, $1)
}
Tested by existing String tests.
We should see some nice performance improvements for string comparison and
dictionary benchmarks.
Here is what I measured at -O on my machine
Name Speedup
Dictionary 2.00x
Dictionary2 1.45x
Dictionary2OfObjects 1.20x
Dictionary3 1.50x
Dictionary3OfObjects 1.45x
DictionaryOfObjects 1.40x
SuperChars 1.60x
rdar://22173647
...and explicitly mark symbols we export, either for use by executables or for runtime-stdlib interaction. Until the stdlib supports resilience we have to allow programs to link to these SPI symbols.
Move the ObjC internal declarations to a public runtime header so they can be shared, and rename _swift_deallocClassInstance to the more descriptive name swift_rootObjCDealloc (and make it only available with ObjC interop).
