alumacc: alternative cmp unification implementation #4000
Conversation
This file contains 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
|
This fails as reordering no longer happens. https://github.com/YosysHQ/yosys/blob/ded586c/tests/opt/opt_expr.ys#L27 |
adrianparvino
commented
Oct 10, 2023
passes/techmap/alumacc.cc
Outdated
| @@ -331,9 +331,6 @@ struct AlumaccWorker | |||
| if (GetSize(C) > 1) | |||
| goto next_macc; | |||
|
|
|||
| if (!subtract_b && B < A && GetSize(B)) | |||
| std::swap(A, B); | |||
|
|
|||
There was a problem hiding this comment.
In hindsight, this can remain, as cmp unification now is order-independent. This also allows the tests to pass.
adrianparvino
force-pushed
the
alumacc-cmp-contravariance
branch
from
ded586c to
de50379
Compare
adrianparvino
force-pushed
the
alumacc-cmp-contravariance
branch
from
de50379 to
1bf1d92
Compare
adrianparvino
changed the title
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
$ltand related are sometimes inhibited from unifying with$subas whenB < A, then the$subcell is unable to swap inputs, but$ltdoes. This resolves this problem by instead consideringsig_aluas an unordered pair mapping.Addendum:
$addand$submight still be unable to unify withshare -aggressivebut changing the behavior [1] causes [2] to fail, so I'm keeping it tocmponly.[1] ded586c#diff-f5a16f8ab735a667cabcdd605b428eeaa92f223f044ef01a91d52141d404633bL334-L336
[2] https://github.com/YosysHQ/yosys/blob/ded586c/tests/opt/opt_expr.ys#L27