In derivatives of loops, no longer allocate boxes for indirect case payloads. Instead, use a custom pullback context in the runtime which contains a bump-pointer allocator.
When a function contains a differentiated loop, the closure context is a `Builtin.NativeObject`, which contains a `swift::AutoDiffLinearMapContext` and a tail-allocated top-level linear map struct (which represents the linear map struct that was previously directly partial-applied into the pullback). In branching trace enums, the payloads of previously indirect cases will be allocated by `swift::AutoDiffLinearMapContext::allocate` and stored as a `Builtin.RawPointer`.
Add differentiation support for non-active `try_apply` SIL instructions.
Notable pullback generation changes:
* Original basic blocks are now visited in a different order:
* starting from the original basic block, all its predecessors
* are visited in a breadth-first search order. This ensures that
* all successors of any block are visited before the block itself.
Resolves TF-433.
Start `linear_function` canonicalization skeleton copying from
`differentiable_function` canonicalization. For now, transpose function
operands are filled in with `undef`.
`JVPCloner.h` is now tiny: `JVPCloner` exposes only a `bool run()` entry point.
All of the implementation is moved to `JVPCloner::Implementation` in
`JVPCloner.cpp`. Methods can be defined directly in `JVPCloner.cpp` without
separate declarations.
`VJPCloner.h` is now tiny: `VJPCloner` exposes only a `bool run()` entry point.
All of the implementation is moved to `VJPCloner::Implementation` in
`VJPCloner.cpp`. Methods can be defined directly in `VJPCloner.cpp` without
separate declarations.
Clarify `llvm_unreachable` after exhaustive switch is needed to silence
MSVC C4715, so we don't accidentally remove it.
Standardize some assertion messages.
Reimplement `PullbackCloner` using the pointer-to-implementation pattern.
`PullbackCloner.h` is now tiny: `PullbackCloner` exposes only a `bool run()`
entry point.
All of the implementation is moved to `PullbackCloner::Implementation` in
`PullbackCloner.cpp`.
Benefits of this approach:
- A main benefit is that methods can be defined directly in `PullbackCloner.cpp`
without needing to separately declare them in `PullbackCloner.h`.
- There is now no code duplication between `PullbackCloner.h` and
`PullbackCloner.cpp`.
- Consequently, method documentation is easier to read because it appears
directly on method definitions, instead of on method declarations in a
separate file. This is important for documentation of `PullbackCloner`
instruction visitor methods, which explain pullback transformation rules.
- Incremental recompilation may be faster since `PullbackCloner.h` changes less
often.
Partially resolves SR-13182.
Add base type parameter to `TangentStoredPropertyRequest`.
Use `TypeBase::getTypeOfMember` instead of `VarDecl::getType` to correctly
compute the member type of original stored properties, using the base type.
Resolves SR-13134.
Reverse-mode differentiation now supports `apply` instructions with multiple
active "semantic results" (formal results or `inout` parameters).
The "cannot differentiate through multiple results" non-differentiability error
is lifted.
Resolves TF-983.
Previously, PullbackEmitter assumed that original values' value category
matches their `TangentVector` types' value category. This was problematic
for loadable types with address-only `TangentVector` types.
Now, PullbackEmitter starts to support differentiation of loadable types with
address-only `TangentVector` types. This patch focuses on supporting and testing
class types, more support can be added incrementally.
Resolves TF-1149.
Use TangentStoredPropertyRequest in differentiation transform.
Improve non-differentiability diagnostics regarding invalid stored
property projection instructions:
`struct_extract`, `struct_element_addr`, `ref_element_addr`.
Diagnose the following cases:
- Original property's type does not conform to `Differentiable`.
- Base type's `TangentVector` is not a struct.
- Tangent property not found: base type's `TangentVector` does not have a
stored property with the same name as the original property.
- Tangent property's type is not equal to the original property's
`TangentVector` type.
- Tangent property is not a stored property.
Resolves TF-969 and TF-970.
- Show SIL type when printing `AdjointValue`.
- Add utilities to print `PullbackEmitter` adjoint value and buffer mappings.
- Print generated VJP before printing generated pullback.
- This is useful because pullback generation may crash after VJP
generation succeeds.
Update differentiation to handle `array.finalize_intrinsic` applications.
`VJPEmitter::visitApplyInst` does standard cloning for these applications.
`PullbackEmitter::visitApplyInst` treats the intrinsic like an identity
function, accumulating result's adjoint into argument's adjoint.
This fixes array literal initialization differentiation.
`DifferentiableFunctionInst` now stores result indices.
`SILAutoDiffIndices` now stores result indices instead of a source index.
`@differentiable` SIL function types may now have multiple differentiability
result indices and `@noDerivative` resutls.
`@differentiable` AST function types do not have `@noDerivative` results (yet),
so this functionality is not exposed to users.
Resolves TF-689 and TF-1256.
Infrastructural support for TF-983: supporting differentiation of `apply`
instructions with multiple active semantic results.
Fix SIL locations and debug scopes in `VJPEmitter` for:
- Pullback struct `struct` instructions
- Predecessor enums `enum` instructions
These instructions are not directly cloned from the original function and should
have auto-generated locations.
Resolves SR-12887: debug scope error for `VJPEmitter`-generated function.
Support differentiation of `is` and `as?` operators.
These operators lower to branching cast SIL instructions, requiring control
flow differentiation support.
Resolves SR-12898.
Add a common helper function `VJPEmitter::createTrampolineBasicBlock`.
Change `VJPEmitter::buildPullbackValueStructValue` to take an original basic
block instead of a terminator instruction.
Add special-case VJP generation support for "semantic member accessors".
This is necessary to avoid activity analysis related diagnostics and simplifies
generated code.
Fix "wrapped property mutability" check in `Differentiable` derived conformnances.
This resolves SR-12642.
Add e2e test using real world property wrappers (`@Lazy` and `@Clamping`).
Support differentiation of property wrapper wrapped value getters and setters.
Create new pullback generation code path for "semantic member accessors".
"Semantic member accessors" are attached to member properties that have a
corresponding tangent stored property in the parent `TangentVector` type.
These accessors have special-case pullback generation based on their semantic
behavior. Currently, only getters and setters are supported.
This special-case pullback generation is currently used for stored property
accessors and property wrapper wrapped value accessors. In the future, it can
also be used to support `@differentiable(useInTangentVector)` computed
properties: SR-12636.
User-defined accesors cannot use this code path because they may use custom
logic that does not semantically perform a member access.
Resolves SR-12639.
This became necessary after recent function type changes that keep
substituted generic function types abstract even after substitution to
correctly handle automatic opaque result type substitution.
Instead of performing the opaque result type substitution as part of
substituting the generic args the underlying type will now be reified as
part of looking at the parameter/return types which happens as part of
the function convention apis.
rdar://62560867
Move differentiation-related SILOptimizer files to
{include/swift,lib}/SILOptimizer/Differentiation/.
This reduces directory nesting and gathers files together.
