Summary:
This diff moves the conversion pass declaration closer to its definition
and makes the namespacing of passes consistent with the rest of the
infrastructure (i.e. `mlir::linalg::createXXXPass` -> `mlir::createXXXPass`).
Reviewers: ftynse, jpienaar, mehdi_amini
Subscribers: rriddle, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72766
Summary:
This diff fixes issues with the semantics of linalg.generic on tensors that appeared when converting directly from HLO to linalg.generic.
The changes are self-contained within MLIR and can be captured and tested independently of XLA.
The linalg.generic and indexed_generic are updated to:
To allow progressive lowering from the value world (a.k.a tensor values) to
the buffer world (a.k.a memref values), a linalg.generic op accepts
mixing input and output ranked tensor values with input and output memrefs.
```
%1 = linalg.generic #trait_attribute %A, %B {other-attributes} :
tensor<?x?xf32>,
memref<?x?xf32, stride_specification>
-> (tensor<?x?xf32>)
```
In this case, the number of outputs (args_out) must match the sum of (1) the
number of output buffer operands and (2) the number of tensor return values.
The semantics is that the linalg.indexed_generic op produces (i.e.
allocates and fills) its return values.
Tensor values must be legalized by a buffer allocation pass before most
transformations can be applied. Such legalization moves tensor return values
into output buffer operands and updates the region argument accordingly.
Transformations that create control-flow around linalg.indexed_generic
operations are not expected to mix with tensors because SSA values do not
escape naturally. Still, transformations and rewrites that take advantage of
tensor SSA values are expected to be useful and will be added in the near
future.
Subscribers: bmahjour, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72555
This is an initial step to refactoring the representation of OpResult as proposed in: https://groups.google.com/a/tensorflow.org/g/mlir/c/XXzzKhqqF_0/m/v6bKb08WCgAJ
This change will make it much simpler to incrementally transition all of the existing code to use value-typed semantics.
PiperOrigin-RevId: 286844725
This CL uses the now standard std.subview in linalg.
Two shortcuts are currently taken to allow this port:
1. the type resulting from a view is currently degraded to fully dynamic to pass the SubViewOp verifier.
2. indexing into SubViewOp may access out of bounds since lowering to LLVM does not currently enforce it by construction.
These will be fixed in subsequent commits after discussions.
PiperOrigin-RevId: 280250129
This operation is a companion operation to the std.view operation added as proposed in "Updates to the MLIR MemRefType" RFC.
PiperOrigin-RevId: 279766410
This CL adds a simple pattern for specifying producer-consumer fusion on Linalg operations.
Implementing such an extension reveals some interesting properties.
Since Linalg operates on a buffer abstraction, the output buffers are specified as in/out parameters to the ops. As a consequence, there are no SSA use-def chains and one cannot specify complex dag input patterns with the current infrastructure.
Instead this CL uses constraints based on the existing linalg dependence analysis to focus the pattern and refine patterns based on the type of op that last wrote in a buffer.
This is a very local property and is less powerful than the generic dag specification based on SSA use-def chains.
This will be generalized in the future.
PiperOrigin-RevId: 277931503
MLIR const-correctness policy is to avoid having `const` on IR objects.
LinalgDependenceGraph is not an IR object but an auxiliary data structure.
Furthermore, it is not updated once constructed unlike IR objects. Add const
qualifiers to get* and find* methods of LinalgDependenceGraph since they are
not modifying the graph. This allows transformation functions that require the
dependence graph to take it by const-reference, clearly indicating that they
are not modifying it (and that the graph may have to be recomputed after the
transformation).
PiperOrigin-RevId: 277731608
This will be used to specify declarative Linalg transformations in a followup CL. In particular, the PatternRewrite mechanism does not allow folding and has its own way of tracking erasure.
PiperOrigin-RevId: 277149158
When the implementation of the strided memref [RFC](https://groups.google.com/a/tensorflow.org/forum/#!msg/mlir/MaL8m2nXuio/1scRqZa6AQAJ) landed, linalg started using this type instead of the now retired !linalg.view.
As static and partially static cases appear, the stride information needs to be maintained properly. In particular, the result type of the subview op was generally incorrect.
This CL fixes the issue by computing a return type that:
1. always has dynamic sizes, which is generally the only correct way to construct a subview in the absence of data padding and/or code versioning.
2. has the same strides as the base strided memref.
Point 1. above can be further refined but will needs further analysis and canonicalization to optimize the particular case where:
1. The base memref has static size along a given dimension.
2. The subview size can be statically derived (e.g. after canonicalization).
3. *And* the subview size is an even divisor of the base memref.
This 3rd constraint is well-known in the case of tiled layouts that don't assume implicit padding: the boundary tile may be only partial and has size given by `problem_size % tile_size`.
Tests are updated as appropriate.
PiperOrigin-RevId: 274578624
This CL finishes the implementation of the Linalg + Affine type unification of the [strided memref RFC](https://groups.google.com/a/tensorflow.org/forum/#!topic/mlir/MaL8m2nXuio).
As a consequence, the !linalg.view type, linalg::DimOp, linalg::LoadOp and linalg::StoreOp can now disappear and Linalg can use standard types everywhere.
PiperOrigin-RevId: 272187165
This CL modifies the linalg-fusion pass such that it does not tile anymore as part of the pass. Tiling is a separate concern that enables linalg fusion but should happen before.
This makes fusion more composable with other decisions.
In particular the fusion pass now becomes greedy and only applies the transformation on a best-effort basis.
This should also let fusion work in a multi-hop fashion with chains of producer/consumers.
Since the fusion pass does not perform tiling anymore, tests are rewritten to be in pretiled form and make the intent of the test clearer (albeit more verbose).
PiperOrigin-RevId: 271357741
This CL adds support for proper cloning of Linalg ops that have regions (i.e. the generic linalg op). This is used to properly implement tiling and fusion for such ops. Adequate tests are added.
PiperOrigin-RevId: 267027176
This interface will allow for providing hooks to interrop with operation folding. The first hook, 'shouldMaterializeInto', will allow for controlling which region to insert materialized constants into. The folder will generally materialize constants into the top-level isolated region, this allows for materializing into a lower level ancestor region if it is more profitable/correct.
PiperOrigin-RevId: 266702972
This change refactors and cleans up the implementation of the operation walk methods. After this refactoring is that the explicit template parameter for the operation type is no longer needed for the explicit op walks. For example:
op->walk<AffineForOp>([](AffineForOp op) { ... });
is now accomplished via:
op->walk([](AffineForOp op) { ... });
PiperOrigin-RevId: 266209552
