This shaves of ~0.5 seconds from ARC when compiling the stdlib on my machine.
I wired up the cache to the delete notification trigger so we are still memory
safe.
As there are no instructions left which produce multiple result values, this is a NFC regarding the generated SIL and generated code.
Although this commit is large, most changes are straightforward adoptions to the changes in the ValueBase and SILValue classes.
In a bunch of use-cases we use stripSinglePredecessorArgs to eliminate this
case. There is no reason to assume that this is being done in the caller of
RCIdentity. Lets make sure that we handle this case here.
rdar://24156136
(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.
