In #85757, part of the changes resolving #68944 is submitted. Most
bridges required for #85757 were previously implemented in #84648. After
#82653 got merged, we have demand for several new bridges in order to
properly support optimizing derivatives of throwing functions via
AutoDiff Closure Specialization pass.
This patch implements:
- **AST:**
* `var optionalObjectType: Type` property of `Type` struct
* `var optionalType: Type` property of `Type` struct
- **SIL:**
* `let name: StringRef` property of `EnumCase` struct
* `func createOptionalSome(operand: Value, type: Type) -> EnumInst`
method of `Builder`
* `func createOptionalNone(type: Type) -> EnumInst` method of `Builder`
ac619010e3 backfired when building the
stdlib on rebranch. This time the problem is reversed: we should be
interpreting an integer as unsigned where we no longer do, here:
8f7af45115/SwiftCompilerSources/Sources/Optimizer/InstructionSimplification/SimplifyLoad.swift (L78).
Rather than treating integers as signed by default, make
`Builder.createIntegerLiteral` accept a generic `FixedWidthInteger`, and
manipulate the value based on the generic type argument's signedness.
This doesn't entirely define away unintentional sign extensions, but
makes this mistake of humouring the parameter type less likely.
The assertion is hit through `TypeValueInst.simplify` when constructing
an integer literal instruction with a negative 64-bit `Swift.Int` and a
bit width of 32 (the target pointer bit width for arm64_32 watchOS).
This happens because we tell the `llvm::APInt` constructor to treat the
input integer as unsigned by default in `getAPInt`, and a negative
64-bit signed integer does not fit into 32 bits when interpreted as
unsigned.
Fix this by flipping the default signedness assumption for the Swift API
and introducing a convenience method for constructing a 1-bit integer
literal instruction, where the correct signedness assumption depends on
whether you want to use 1 or -1 for 'true'.
In the context of using an integer to construct an `llvm::APInt`, there
are 2 other cases where signedness matters that come to mind:
1. A non-decimal integer literal narrower than 64 bits, such as
`0xABCD`, is used.
2. The desired bit width is >64, since `llvm::APInt` can either
zero-extend or sign-extend the 64-bit integer it accepts.
Neither of these appear to be exercised in SwiftCompilerSources, and
if we ever do, the caller should be responsible for either (1)
appropriately extending the literal manually, e.g.
`Int(Int16(bitPattern: 0xABCD))`, or (2) passing along the appropriate
signedness.
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.
We are going to need to add more flags to the various checked cast
instructions. Generalize the CastingIsolatedConformances bit in all of
these SIL instructions to an "options" struct that's easier to extend.
Precursor to rdar://152335805.
It derives the address of the first element of a vector, i.e. a `Builtin.FixedArray`, from the address of the vector itself.
Addresses of other vector elements can then be derived with `index_addr`.
When performing a dynamic cast to an existential type that satisfies
(Metatype)Sendable, it is unsafe to allow isolated conformances of any
kind to satisfy protocol requirements for the existential. Identify
these cases and mark the corresponding cast instructions with a new flag,
`[prohibit_isolated_conformances]` that will be used to indicate to the
runtime that isolated conformances need to be rejected.
* factor out common methods of AST Type/CanonicalType into a `TypeProperties` protocol.
* add more APIs to AST Type/CanoncialType.
* move `MetatypeRepresentation` from SIL.Type to AST.Type and implement it with a swift enum.
* let `Builder.createMetatype` get a CanonicalType as instance type, because the instance type must not be a lowered type.
Some utilities, like Builder.insert(after:) pass a Builder object that
represents an insertion point. That insertion point is sometimes needed to
determine which instructions to create (endApply vs. abortApply). But there is
no way to recover the insertion point. We don't want to simply return an
instruction, because that could be interpreted in different ways. Instead we
provide insertion block, but only in those situations where it makes sense and can't
be used incorrectly.
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
This makes ManagedBuffer available and usable in Embedded Swift, by:
- Removing an internal consistency check from ManagedBuffer that relies on metatypes.
- Making the .create() API transparent (to hoist the metatype to the callee).
- Adding a AllocRefDynamicInst simplification to convert `alloc_ref_dynamic` to `alloc_ref`, which removes a metatype use.
- Adding tests for the above.
The OSSA elimination pass has not yet been moved below all high level
function passes. Until that work has been completed the Autodiff
closure-spec optimization pass cannot solely support OSSA instructions.
In preparation for inserting mark_dependence instructions for lifetime
dependencies early, immediately after SILGen. That will simplify the
implementation of borrowed arguments.
Marking them unresolved is needed to make OSSA verification
conservative until lifetime dependence diagnostics runs.
Optionally, the dependency to the initialization of the global can be specified with a dependency token `depends_on <token>`.
This is usually a `builtin "once"` which calls the initializer for the global variable.
The dependent 'value' may be marked 'nonescaping', which guarantees that the
lifetime dependence is statically enforceable. In this case, the compiler
must be able to follow all values forwarded from the dependent 'value', and
recognize all final (non-forwarded, non-escaping) use points. This implies
that `findPointerEscape` is false. A diagnostic pass checks that the
incoming SIL to verify that these use points are all initially within the
'base' lifetime. Regular 'mark_dependence' semantics ensure that
optimizations cannot violate the lifetime dependence after diagnostics.
* `alloc_vector`: allocates an uninitialized vector of elements on the stack or in a statically initialized global
* `vector`: creates an initialized vector in a statically initialized global
