[AutoDiff] Support '@differentiable(linear)' function conversion. #27687
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
- Support the following implicit conversions:
- Non-differentiable to `@differentiable(linear)`
- Sema: Emit `LinearFunctionExpr`.
- SILGen: Lower `LinearFunctionExpr` to `linear_function`.
- `@differentiable(linear)` to non-differentiable
- Sema: Emit `LinearFunctionExtractOriginalExpr`.
- SILGen: Lower `LinearFunctionExtractOriginalExpr` to `linear_function_extract [original]`.
- Reject the following implicit conversions:
- `@differentiable` to `@differentiable(linear)`
- This conversion is not rejected because a `@differentiable` function can never come directly from a closure expression or from a declaration/member reference.
- `@differentiable(linear)` to `@differentiable` ([TF-908](https://bugs.swift.org/browse/TF-908))
- This is supported by design, but is not yet implemented due to its complexity. This requires thunking `@differentiable(linear)` to a derivative (JVP) function where the derivative function returns the original result and the same linear map with `@nondiff` parameters partial-applied away.
- Properly handle `linear_function`, `differentiable_function_extract`, and `linear_function_extract` in `swift::isGuaranteedForwardingValueKind` and `swift::isOwnershipForwardingValueKind`. This fixed a previously uncaught assertion, which was because `differentiable_function_extract` was in `swift::isOwnershipForwardingValueKind` while it should really be in `swift::isGuaranteedForwardingValueKind`.
For complete conversion rules among `@differentiable` functions, see [Differentiable Programming Mega-Proposal - Type conversion](https://github.com/dan-zheng/swift/blob/differentiable-programming/docs/DifferentiableProgramming.md#type-conversion).
Resolves [TF-900](https://bugs.swift.org/browse/TF-900).
rxwei
commented
Oct 15, 2019
| @@ -1,6 +1,5 @@ | |||
| // RUN: %target-swift-frontend -dump-ast %s | %FileCheck %s -check-prefix=CHECK-AST | |||
| // RUN: %target-swift-frontend -emit-silgen %s | %FileCheck %s -check-prefix=CHECK-SILGEN | |||
| // RUN: %target-swift-frontend -emit-sil %s | %FileCheck %s -check-prefix=CHECK-SIL | |||
Contributor
Author
There was a problem hiding this comment.
This RUN line was removed because differentiable_function_silgen.swift is supposed to be a SILGen test, not a SIL canonicalization test.
dan-zheng
approved these changes
Oct 15, 2019
Contributor
Author
|
@swift-ci please test tensorflow |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
@differentiable(linear)LinearFunctionExpr.LinearFunctionExprtolinear_function.@differentiable(linear)to non-differentiableLinearFunctionExtractOriginalExpr.LinearFunctionExtractOriginalExprtolinear_function_extract [original].@differentiableto@differentiable(linear)@differentiablefunction can never come directly from a closure expression or from a declaration/member reference.@differentiable(linear)to@differentiable(TF-908)@differentiable(linear)to a derivative (JVP) function where the derivative function returns the original result and the same linear map with@nondiffparameters partial-applied away.linear_function,differentiable_function_extract, andlinear_function_extractinswift::isGuaranteedForwardingValueKindandswift::isOwnershipForwardingValueKind. This fixed a previously uncaught assertion, which was becausedifferentiable_function_extractwas inswift::isOwnershipForwardingValueKindwhile it should really be inswift::isGuaranteedForwardingValueKind.For complete conversion rules among
@differentiablefunctions, see Differentiable Programming Mega-Proposal - Type conversion.Resolves TF-900.