Yield a zero derivative when a forward-mode call base has no tangent. - #1913
Merged
Conversation
A member/operator call whose base object does not depend on the differentiation variable has no forward tangent, and so no pushforward to call. VisitCallExpr took the address of that tangent regardless: where it was void this failed with "cannot take the address of an rvalue of type 'void'", and otherwise a null argument was passed on to the pushforward. Return a zero derivative instead, since such a call contributes nothing to the directional derivative. Type it after the call's own result rather than int, so it composes with a caller expecting the callee's type.
Contributor
|
clang-tidy review says "All clean, LGTM! 👍" |
Codecov Report✅ All modified and coverable lines are covered by tests. 📢 Thoughts on this report? Let us know! |
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
A member/operator call whose base object does not depend on the differentiation variable has no forward tangent, and so no pushforward to call. VisitCallExpr took the address of that tangent regardless: where it was void this failed with "cannot take the address of an rvalue of type 'void'", and otherwise a null argument was passed on to the pushforward.
Return a zero derivative instead, since such a call contributes nothing to the directional derivative. Type it after the call's own result rather than int, so it composes with a caller expecting the callee's type.