Before this commit, passes that were attempting to maintain the call
graph would actually build it if it wasn't already valid, just for the
sake of maintaining it.
Now we only maintain it if we already had a valid call graph built.
Swift SVN r26873
Now that we can check isNative and NoDTC (no deffered type check needed) with a single bit-mask operation,
it makes sense to have a single array property call for it.
I replaced the the semantics call array.props.needsElementTypeCheck with array.props.isNativeNoDTC,
which is the combination of isNative && !needsElementTypeCheck. I kept array.props.isNative, which is not used for now,
but might be useful in the future, e.g. for array operations which don't care about type checks.
The optimized SIL for a class array access arr[i] now contains the minimum of 4 basic blocks.
PerfTests show +25% for DeltaBlue and some improvemements for -Onone.
Swift SVN r26871
We ignore calls to ArraySemantic functions when we hoist uniqueness checks. With
+0 self, this is disrupted by the release that now is in the caller instead of
the callee.
This patch fixes that problem by teaching COWArrayOpts about "guaranteed call
sequences". This is the following pattern:
retain(x)
... nothing that decrements reference counts ...
call f1(@guaranteed_self x)
... nothing that decrements or uses ref counts ...
call f2(@guaranteed_self x)
... nothing that decrements or uses ref counts ...
...
... nothing that decrements or uses ref counts ...
call f$(n-1)(@guaranteed_self x)
... nothing that decrements or uses ref counts ...
call fn(@guaranteed_self x)
... nothing that uses ref counts ...
release(x)
This pattern is created when there are a bunch of guaranteed calls together in a
row (which seems to happen at the "semantic" SIL level). We pattern match the
sequence and then verify that all of the calls are semantic calls. If the
verification succeeds, we can hoist the uniqueness check.
rdar://20340699
Swift SVN r26835
Given a strong_pin for which we have not yet seen a strong_unpin, a safe
guaranteed call sequence is of the following form:
retain(x)
call f(@guaranteed x)
release(x)
where f is an array semantic call that we know does not touch globals and thus
are known to not change ref counts.
rdar://20305817
Swift SVN r26662
This reverts commit r25925.
We cannot assume that these functions are not mayRelease because they call
Objective C functions which we must assume to be mayRelase.
Swift SVN r26107
