If a transformation should be a canonicalization is an orthogonal
question to if a transformation should be implemented as a
`RewritePattern` or a `fold` method. The later is an implementation
detail.
This patch adds a suggestion to always implement a canonicalization as a
`fold` pattern if possible, as they are a restricted subset of a
`RewritePattern`.
This has been a common source of confusion, as to when to implement a
canonicalization as a fold method or a RewritePattern.
This is part of the RFC for a better fold API: https://discourse.llvm.org/t/rfc-a-better-fold-api-using-more-generic-adaptors/67374
This patch implements the required foldHook changes and the TableGen machinery for generating `fold` method signatures using `FoldAdaptor` for ops, based on the value of `useFoldAPI` of the dialect. It may be one of 2 values, with convenient named constants to create a quasi enum. The new `fold` method will then be generated if `kEmitFoldAdaptorFolder` is used.
Since the new `FoldAdaptor` approach is strictly better than the old signature, part of this patch updates the documentation and all example to encourage use of the new `fold` signature.
Included are also tests exercising the new API, ensuring proper construction of the `FoldAdaptor` and proper generation by TableGen.
Differential Revision: https://reviews.llvm.org/D140886
This moves the documentation for defining dialects, attributes/types,
and operations into a new `DefiningDialects` folder. This helps to
keep the documentation grouped together, making it easier to find
related documentation.
Differential Revision: https://reviews.llvm.org/D137594
We don't actually have any documentation today for how to
declaratively define a dialect. This commit rectifies that and properly
documents how to define a Dialect in tablegen, and details all of
the possible fields.
Differential Revision: https://reviews.llvm.org/D123258
This is the fourth and final patch in a series of patches fixing markdown links and references inside the mlir documentation. This patch combined with the other three should fix almost every broken link on mlir.llvm.org as far as I can tell.
This patch in particular addresses all Markdown files in the top level docs directory.
Differential Revision: https://reviews.llvm.org/D103032
This provides a simplified way to implement 'matchAndRewrite' style
canonicalization patterns for ops that don't need the full power of
RewritePatterns. Using this style, you can implement a static method
with a signature like:
```
LogicalResult AssertOp::canonicalize(AssertOp op, PatternRewriter &rewriter) {
return success();
}
```
instead of dealing with defining RewritePattern subclasses. This also
adopts this for a few canonicalization patterns in the std dialect to
show how it works.
Differential Revision: https://reviews.llvm.org/D99143
This doesn't change APIs, this just cleans up the many in-tree uses of these
names to use the new preferred names. We'll keep the old names around for a
couple weeks to help transitions.
Differential Revision: https://reviews.llvm.org/D99127
Summary: This updates the canonicalization documentation, and properly documents the different ways of canonicalizing operations.
Differential Revision: https://reviews.llvm.org/D77490
