1. During identifyAccess, determine if there are either any
identical accesses or an accesses that aren't already marked
no_nested_storage. If there are neither, then skip the subsequent
data flow analysis.
2. In the new StorageSet, indicate whether identical storage was
seen elsewhere in the function. During dataflow, only add an access
to the out-of-scope access set if was marked as having identical
storage with another access.
3. During data flow, don't track in scope conflicts for
instructions already marked [no_nested_conflict].
The recursivelyDeleteTriviallyDeadInstructions utility takes a
callBack to be called for every deleted instruction. However, it
wasn't passing this callBack to eraseFromParentWithdebugInsts. The
callback was used to update an iterator in some cases, so not calling
it resulted in iterator invalidation.
Doing this also cleans up the both APIs:
recursivelyDeleteTriviallyDeadInstructions and eraseFromParentWithdebugInsts.
This will make the forthcoming CanonicalizeInstruction interface more
clear.
This is generally the better approach to utilities that mutate the
instruction stream. It avoids the temptation to assume that only a
single instruction will be deleted or that only instructions before
the current iterator will be deleted. This often happens to work but
eventually fails in the presense of debug and end-of-scope
instructions.
A function returning an iterator has a more clear contract than one
accepting some iterator reference of unknown
providence. Unfortunately, it doesn't work at the lowest level of
utilities, such as recursivelyDeleteTriviallyDeadInstructions, where
we want to handle instruction batches.
This is a large patch; I couldn't split it up further while still
keeping things working. There are four things being changed at
once here:
- Places that call SILType::isAddressOnly()/isLoadable() now call
the SILFunction overload and not the SILModule one.
- SILFunction's overloads of getTypeLowering() and getLoweredType()
now pass the function's resilience expansion down, instead of
hardcoding ResilienceExpansion::Minimal.
- Various other places with '// FIXME: Expansion' now use a better
resilience expansion.
- A few tests were updated to reflect SILGen's improved code
generation, and some new tests are added to cover more code paths
that previously were uncovered and only manifested themselves as
standard library build failures while I was working on this change.
Actually: generate the array of (key, value) tuples in the data section, which is then passed to Dictionary.init(dictionaryLiteral:)
We already do this for simple arrays, e.g. arrays with trivial element types.
The only change needed for dictionary literals is to support tuple types in the ObjectOutliner.
The effect of this optimization is a significant reduction in code size for dictionary literals - and an increase in data size.
But in most cases there is a considerable net win for code+data size in total.
Disable constant folding and jump threading for functions with > 10000 blocks.
Those optimizations are not strictly linear with the number of blocks and cause compile time issues if the function is really huge.
SR-10209
rdar://problem/49522869
This is an obvious drive-by fix. It will crash when building
Foundation after I commit changes to the pipeline. My attempts at
creating a unit test were unsuccessful because it depends on some
interaction between inlining and specialization heuristics.
Reuse AccessStorageAnalysis to summarize accesses.
Don't ignore call sites in loops.
Don't consider a read access in a loop to conflict with a read
outside.
Use the unidentified access flag from the analysis.
Remove extraneous code, some of which was unreachable.
General cleanup.
Now we handle this case:
%stack = alloc_stack $Protocol
copy_addr %var to [initialization] %stack
open_existential_addr immutable_access %stack
...
destroy_addr %stack
dealloc_stack %stack
We only do this if we have immutable_access. To be conservative I still only let
the normal whitelist of other instructions through.
I am adding this optimization since I am going to be eliminating a SILGen
peephole so I can enable SIL ownership verification everywhere.
Directly implement the data flow. Eliminate the extraneous work.
Remove cubic behavior. Do a single iteration of the data flow state at
each program point only performing the necessary set operations. At
unidentified access, clear the sets for simplicity and efficiency.
This cleanup results in significant functional changes:
- Allowing scopes to merge even if they are enclosed.
- Handling unidentified access conservatively.
Note that most of the added lines of code are comments.
Somehow this cleanup incidentally fixes:
<rdar://problem/48514339> swift compiler hangs building project
(I expected the subsequent loop summary cleanup to fix that problem.)
The optimization already proves that there are no potential conflicts
between the two merged scopes, so merging them can't introduce a new
nested conflict.
AccessSummary was storing unnecessary state in every per-block entry in the
global map. It was also making most of the code in this pass very hard to read.
Rewriting mergePredAccesses allows AccessSummary to be removed. The
new implementation also avoids unnecessary DenseMap lookups.
There is also a functional change. mergePredAccesses was clearing the
state of predecessor blocks. This isn't logical and had no explanation.
Most of the API's operate on the data flow state (RegionState) with
respect to the information for a given access (AccessInfo). Calling
them both "info" made the code completely indecipherable.
The ownership kind is Any for trivial types, or Owned otherwise, but
whether a type is trivial or not will soon depend on the resilience
expansion.
This means that a SILModule now uniques two SILUndefs per type instead
of one, and serialization uses two distinct sentinel IDs for this
purpose as well.
For now, the resilience expansion is not actually used here, so this
change is NFC, other than changing the module format.
