Previously, the SILVerifier always recomputed DominanceInfo for
every function it verified. This is unnecesscary if previous passes have not
invalidated the analysis.
Query DominanceInfo from SIL's analysis infrastructure and pass that for
verification.
This speeds up -sil-verify-all builds of standard library around 10% and has
the potential to speed up macos CI testing (did not measure).
Prevents situations when actor isolation ends up not being set
un-intentionally i.e. when cloning, specializating, or creating
thunks.
The thunks get `unspecified` isolation at the moment.
SIL functions should always have actor isolation set, otherwise
it could lead to wrong deductions in optimization passes like
`SendNonSendable` or `OptimizeHopToExecutor`.
This is a first step to move isolation assignment into
`SILFunction::create`.
There are passes that rely on the isolation being present after
specialization and other optmizations i.e. `SendNonSendable` which
means the clones need to always preserve the isolation of the
original function.
With this option an MD5 hash of the SIL is printed after each function or module pass - if the pass has changed the SIL.
This is useful for finding non-determinisms in the optimizer.
This is the first step to remove the ability for bootstrapping (without a swift host compiler).
This change is intended to find any problems in CI before we really drop the support for bootstrapping.
This new OSSA invariant simplifies many optimizations because they don't have to take care of the corner case of incomplete lifetimes in dead-end blocks.
The implementation basically consists of these changes:
* add the lifetime completion utility
* add a flag in SILFunction which tells optimization that they need to run the lifetime completion utility
* let all optimizations complete lifetimes if necessary
* enable the ownership verifier to check complete lifetimes
These two new invariants eliminate corner cases which caused bugs if optimization didn't handle them.
Also, it will significantly simplify lifetime completion.
The implementation basically consists of these changes:
* add a flag in SILFunction which tells optimization if they need to take care of infinite loops
* add a utility to break infinite loops
* let all optimizations remove unreachable blocks and break infinite loops if necessary
* add verification to check the new SIL invariants
The new `breakIfniniteLoops` utility breaks infinite loops in the control flow by inserting an "artificial" loop exit to a new dead-end block with an `unreachable`.
It inserts a `cond_br` with a `builtin "infinite_loop_true_condition"`:
```
bb0:
br bb1
bb1:
br bb1 // back-end branch
```
->
```
bb0:
br bb1
bb1:
%1 = builtin "infinite_loop_true_condition"() // always true, but the compiler doesn't know
cond_br %1, bb2, bb3
bb2: // new back-end block
br bb1
bb3: // new dead-end block
unreachable
```
Pass-invocations can be nested if a module pass creates an inner context for a specific function to modify.
This change
* removes the SwiftPassInvocation instance from SILCombine and let SILCombine use the current SwiftPassInvocation
* correctly use the innermost SwiftPassInvocation in various bridged utilities
This allows to move many SIL APIs and utilities, which require a context, to the SIL module.
The SIL-part of SwiftPassInvocation is extracted into a base class SILContext which now lives in SIL.
Also: simplify the begin/end-pass functions of the SwiftPassInvocation.
* move the "SILCombine passes" into a separate file `Simplifications.def` which lives in the SILCombiner directory
* group passes by kind
* rename PASS -> LEGACY_PASS and add a comment to make clear that new passes should be implemented in Swift
NFC
Casts always work with formal rather than lowered types.
This fixes a potential bug when lowered types are different than formal types, like function types.
If a pass forgot to call invalidateAnalysis but deleted some instructions, the pass-manager can fix this.
Currently following passes do not invalidate analysis when they change the SIL:
* LowerTupleAddrConstructor
* DestroyAddrHoisting
* MoveOnlyChecker
* PredictableDeadAllocationElimination
Ideally we should fix those passes. But with this addition in the pass-manager it's not strictly necessary.
Fixes a compiler crash.
In Embedded Swift, witness method lookup is done from specialized witness tables.
For this to work, the type of witness_method must be specialized as well.
Otherwise the method call would be done with wrong parameter conventions (indirect instead of direct).
As the optimizer uses more and more AST stuff, it's now time to create an "AST" module.
Initially it defines following AST datastructures:
* declarations: `Decl` + derived classes
* `Conformance`
* `SubstitutionMap`
* `Type` and `CanonicalType`
Some of those were already defined in the SIL module and are now moved to the AST module.
This change also cleans up a few things:
* proper definition of `NominalTypeDecl`-related APIs in `SIL.Type`
* rename `ProtocolConformance` to `Conformance`
* use `AST.Type`/`AST.CanonicalType` instead of `BridgedASTType` in SIL and the Optimizer
MandatoryPerformanceOptimizations already did most of the vtable specialization work.
So it makes sense to remove the VTableSpecializerPass completely and do everything in MandatoryPerformanceOptimizations.
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
[serialized_for_package] if Package CMO is enabled. The latter kind
allows a function to be serialized even if it contains loadable types,
if Package CMO is enabled. Renamed IsSerialized_t as SerializedKind_t.
The tri-state serialization kind requires validating inlinability
depending on the serialization kinds of callee vs caller; e.g. if the
callee is [serialized_for_package], the caller must be _not_ [serialized].
Renamed `hasValidLinkageForFragileInline` as `canBeInlinedIntoCaller`
that takes in its caller's SerializedKind as an argument. Another argument
`assumeFragileCaller` is also added to ensure that the calle sites of
this function know the caller is serialized unless it's called for SIL
inlining optimization passes.
The [serialized_for_package] attribute is allowed for SIL function, global var,
v-table, and witness-table.
Resolves rdar://128406520
Compute, update and handle borrowed-from instruction in various utilities and passes.
Also, used borrowed-from to simplify `gatherBorrowIntroducers` and `gatherEnclosingValues`.
Replace those utilities by `Value.getBorrowIntroducers` and `Value.getEnclosingValues`, which return a lazily computed Sequence of borrowed/enclosing values.
eeckstein
Pavel Yaskevich
Meghana Gupta
Pavel Yaskevich
Aidan Hall
Nate Chandler
Andrew Trick
Meghana Gupta
Kuba Mracek
Tim Kientzle
Ellie Shin
Kshitij
Ben Barham