replaced by retain release code motion. This code has been disabled for sometime now.
This should bring the retain release code motion into a close. The retain release
code motion pipeline looks like this. There could be some minor cleanups after this though.
1. We perform a global data flow for retain release code motion in RRCM (RetainReleaseCodeMotion)
2. We perform a local form of retain release code motion in SILCodeMotion. This is more
for cases which can not be handled in RRCM. e.g. sinking into a switch is more efficiently
done in a local form, the retain is not needed on the None block. Release on SILArgument needs
to be split to incoming values, this can not be done in RRCM and other cases.
3. We do not perform code motion in ASO, only elimination which are very important.
Some modifications to test cases, they look different, but functionally the same.
RRCM has this canonicalization effect, i.e. it uses the rc root, instead of
the SSA value the retain/release is currently using. As a result some test cases need
to be modified.
I also removed some test cases that do not make sense anymore and lot of duplicate test
cases between earlycodemotion.sil and latecodemotion.sil. These tests cases only have retains
and should be used to test early code motion.
...in code that I wrote. The integrated REPL, deprecated though it may
be, does not have an associated DeclContext because its SourceFile is
not considered complete. (The proper LLDB REPL does not suffer from
this problem because they use a new SourceFile for every block of
input.)
Elsewhere, tighten up code that may have hit similar bugs, though we
haven't seen anything hit these yet.
rdar://problem/26476281
Several functionalities have been added to FSO over time and the logic has become
muddled.
We were always looking at a static image of the SIL and try to reason about what kind of
function signature related optimizations we can do.
This can easily lead to muddled logic. e.g. we need to consider 2 different function
signature optimizations together instead of independently.
Split 1 single function to do all sorts of different analyses in FSO into several
small transformations, each of which does a specific job. After every analysis, we produce
a new function and eventually we collapse all intermediate thunks to in a single thunk.
With this change, it will be easier to implement function signature optimization as now
we can do them independently now.
Small modifications to the test cases.
In failable initializers the "return from initializer without initializing all stored properties" (resp. "return from enum initializer method without storing to 'self'" for enums) diagnostic is now reported at the early return instead of the end of the initializer.
Even though FRem was added as a builtin, this switch was not updated
accordingly. Update the switch and add a test case.
We really should transition all of the switches in this code to be covered
switches so that when builtins are added, it is obvious to know where things
need to be updated...
rdar://26250330
We don't sink open_existential_* instructions, because there may be some instructions depending on them, e.g. ametatype_inst, etc. But this kind of dependency cannot be expressed in SIL as a use yet. As a result, sinking open_existential may break the invariant that these instructions should dominate their uses.
Shaves about 19% of the time from the construction of these sets. The
SmallVector size was chosen to minimize the number of dynamic
allocations we end up doing while building the stdlib. This should be a
reasonable size for most projects, too. It's a bit wasteful in space,
but the total amount of allocated space here is pretty small to begin
with.
For details see the comment in ConditionForwarding.cpp.
This optimization pass helps to optimize loops iterating over closed ranges, e.g. for i in 0...n { }
