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.
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.
And use project_box to get to the address value.
SILGen now generates a project_box for each alloc_box.
And IRGen re-uses the address value from the alloc_box if the operand of project_box is an alloc_box.
This lets the generated code be the same as before.
Other than that most changes of this (quite large) commit are straightforward.
The code in question was the following:
auto *RetainArray = dyn_cast_or_null<StrongRetainInst>(getInstBefore(Call));
if (!RetainArray && MayHaveBridgedObjectElementType)
return false;
auto *ReleaseArray = dyn_cast_or_null<StrongReleaseInst>(getInstAfter(Call));
if (!ReleaseArray && MayHaveBridgedObjectElementType)
return false;
if (ReleaseArray &&
ReleaseArray->getOperand() != RetainArray->getOperand())
return false;
There is no check in the last if if RetainArray is not nullptr even though it is
possible for it to be so.
Found by clang static analyzer.
Having a separate address and container value returned from alloc_stack is not really needed in SIL.
Even if they differ we have both addresses available during IRGen, because a dealloc_stack is always dominated by the corresponding alloc_stack in the same function.
Although this commit quite large, most changes are trivial. The largest non-trivial change is in IRGenSIL.
This commit is a NFC regarding the generated code. Even the generated SIL is the same (except removed #0, #1 and @local_storage).
This enables array value propagation in array literal loops like:
for e in [2,3,4] {
r += e
}
Allowing us to completely get rid of the array.
rdar://19958821
SR-203
(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.
