iterator/pointer comparison issue that yields undefined behavior. This updates
Swift for the landing of this change in swift-llvm/stable.
I am going to cherry-pick the given change into swift-llvm/stable since there is no
reason not to do this now and it will prevent more of these conversions from
creeping into the code base.
We really want to avoid as much undefined behavior as we possibly can.
This is done by splitting the transformation into an analysis phase and a transformation phase (which does not use the dominator tree anymore).
The domintator tree is recalucated once after the whole function is processed.
This change eventually solves the compile time problem of rdar://problem/24410167.
SILValue.h/.cpp just defines the SIL base classes. Referring to specific instructions is a (small) kind of layering violation.
Also I want to keep SILValue small so that it is really just a type alias of ValueBase*.
NFC.
This just runs a transform range on getSuccessor()'s ArrayRef<SILSuccessor> so
one does not need to always call Successor.getBB() when iterating over successor
blocks. Instead the transform range does that call for you.
I also updated some loops to use this new SILBasicBlock method to make sure that
the code is tested out by tests that are already in tree. All these places
should be functionally the same albeit a bit cleaner.
(libraries now)
It has been generally agreed that we need to do this reorg, and now
seems like the perfect time. Some major pass reorganization is in the
works.
This does not have to be the final word on the matter. The consensus
among those working on the code is that it's much better than what we
had and a better starting point for future bike shedding.
Note that the previous organization was designed to allow separate
analysis and optimization libraries. It turns out this is an
artificial distinction and not an important goal.
