9 Commits

Author SHA1 Message Date
Alex Zinenko
c214cee772 [mlir] improve error handling in Linalg op splitting
In several cases, the splitting may be known to be a noop, i.e., produce
no second part. Thread this information through the transform utilities
to the transform dialect, and differentiate it from the error state.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D141138
2023-01-06 18:35:08 +01:00
Matthias Springer
b169643f3a [mlir][interfaces] Remove getDestinationOperands from TilingInterface
`getDestinationOperands` was almost a duplicate of `DestinationStyleOpInterface::getOutputOperands`. Now that the interface has been moved to mlir/Interfaces, it is no longer needed.

Differential Revision: https://reviews.llvm.org/D136240
2022-10-24 09:26:19 +02:00
Matthias Springer
547942841f [mlir][interfaces] Drop dest/tileDestOperands from TilingInterface
`getTiledImplementation`/`generateResultTileValue` only computes the tiled operation, but does not insert the result into any tensor.

Differential Revision: https://reviews.llvm.org/D133015
2022-09-01 08:53:53 +02:00
Alex Zinenko
70e99f387a [mlir] Make ViewLikeInterface Range work with attributes
While most of methods in ViewLikeInterface accept an `OpFoldResult` for
the offset/size/stride that may be static, represented as `Attribute`,
or dynamic, represented as `Value`, the `Range` abstraction only
accepted `Values`. This can often lead to known-constant
offset/size/strides being materialized into constant operations and
hinder further constant propagation without explicitly running the
constant folding pass. This often leads to a more complicated than
necessary addressing code being emitted. Switch `Range` to use
`OpFoldResult`. Code that uses `Range` currently keeps materializing the
constants to minimize the effect of this change on the IR. Further
commits will make use of this.

Reviewed By: nicolasvasilache, mravishankar

Differential Revision: https://reviews.llvm.org/D129633
2022-07-27 08:52:13 +00:00
Alex Zinenko
08a1b07e7c [mlir] Partially port splitting transform to TilingInterface
The structured op splitting transformation is conceptually similar to
tiling in the sense that it decomposes the iteration space of the
original op into several parts. Therefore, it is possible to implement
it using the TilingInterface to operate on iteration spaces and their
parts. However, the implementation also requires to pass updated input
operands, which is not supported by the interface, so the implementation
currently remains Linalg-specific.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D129564
2022-07-27 08:52:08 +00:00
Alex Zinenko
a5c802a429 [mlir] fold more eagerly in structured op splitting
Existing implementation of structured op splitting creates several
affine.apply and affine.min operations in its subshape computation.
As these shapes are further used in data slice extraction, this may lead
to slice shapes being dynamic even when the original shapes and the
splitting point are static. This is particularly visible when splitting
is combined with further subsetting transformations such as tiling. Use
composition and folding more aggressively in splitting to avoid this.

In particular, introduce a `createComposedAffineMin` function that the
affine map used in "min" with the maps used by any `affine.apply` that
may be feeding the operands to the "min". This enables production of
more static shapes. Also introduce a `createComposedFoldedAffineApply`
function that combines the existing `createComposedAffineApply` with
in-place folding to propagate constants produced by zero-input affine
maps. Using these when splitting allows the subsequent canonicalizer
pass to recover static shapes for structured ops.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D129379
2022-07-12 15:06:55 +00:00
Alex Zinenko
81b62f7feb [mlir] Handle linalg.index correctly in TilingInterface
The existing implementation of the TilingInterface for Linalg ops was not
modifying the `linalg.index` ops contained within other Linalg ops (they need
to be summed up with the values of respective tile loop induction variables),
which led to the interface-based tiling being incorrect for any Linalg op with
index semantics.

In the process, fix the function performing the index offsetting to use the
pattern rewriter API instead of RAUW as it is being called from patterns and
may mess up the internal state of the rewriter. Also rename the function to
clearly catch all uses.

Depends On D129365

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D129366
2022-07-12 12:36:33 +00:00
Alex Zinenko
4e4a4c0576 [mlir] Allow Tile transform op to take dynamic sizes
Extend the definition of the Tile structured transform op to enable it
accepting handles to operations that produce tile sizes at runtime. This is
useful by itself and prepares for more advanced tiling strategies. Note that
the changes are relevant only to the transform dialect, the tiling
transformation itself already supports dynamic sizes.

Depends On D129216

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D129217
2022-07-12 12:21:54 +00:00
Alex Zinenko
ff6e5508d6 [mlir] Structured transforms: introduce op splitting
Introduce a new transformation on structured ops that splits the iteration
space into two parts along the specified dimension. The index at which the
splitting happens may be static or dynamic. This transformation can be seen as
a rudimentary form of index-set splitting that only supports the splitting
along hyperplanes parallel to the iteration space hyperplanes, and is therefore
decomposable into per-dimension application.

It is a key low-level transformation that enables independent scheduling for
different parts of the iteration space of the same op, which hasn't been
possible previously. It may be used to implement, e.g., multi-sized tiling. In
future, peeling can be implemented as a combination of split-off amount
computation and splitting.

The transformation is conceptually close to tiling in its separation of the
iteration and data spaces, but cannot be currently implemented on top of
TilingInterface as the latter does not properly support `linalg.index`
offsetting.

Note that the transformation intentionally bypasses folding of
`tensor.extract_slice` operations when creating them as this folding was found
to prevent repeated splitting of the same operation because due to internal
assumptions about extract/insert_slice combination in dialect utilities.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D129090
2022-07-07 13:19:44 +02:00