12 Commits

Author SHA1 Message Date
MaheshRavishankar
d380b582f7 [mlir][Linalg] Make LinalgBaseTilingPattern not delete the original operation.
The LinalgTilingPattern class dervied from the base deletes the
original operation. This allows for the use case where the more
transformations are necessary on the original operation after
tiling. In such cases the pattern can derive from
LinalgBaseTilingPattern instead of LinalgTilingPattern.

Differential Revision: https://reviews.llvm.org/D87308
2020-09-11 00:39:22 -07:00
Nicolas Vasilache
3110e7b077 [mlir] Introduce AffineMinSCF folding as a pattern
This revision adds a folding pattern to replace affine.min ops by the actual min value, when it can be determined statically from the strides and bounds of enclosing scf loop .

This matches the type of expressions that Linalg produces during tiling and simplifies boundary checks. For now Linalg depends both on Affine and SCF but they do not depend on each other, so the pattern is added there.
In the future this will move to a more appropriate place when it is determined.

The canonicalization of AffineMinOp operations in the context of enclosing scf.for and scf.parallel proceeds by:
  1. building an affine map where uses of the induction variable of a loop
  are replaced by `%lb + %step * floordiv(%iv - %lb, %step)` expressions.
  2. checking if any of the results of this affine map divides all the other
  results (in which case it is also guaranteed to be the min).
  3. replacing the AffineMinOp by the result of (2).

The algorithm is functional in simple parametric tiling cases by using semi-affine maps. However simplifications of such semi-affine maps are not yet available and the canonicalization does not succeed yet.

Differential Revision: https://reviews.llvm.org/D82009
2020-08-07 14:30:38 -04:00
River Riddle
3e98fbf4f5 [mlir] Refactor RewritePatternMatcher into a new PatternApplicator class.
This class enables for abstracting more of the details for the rewrite process, and will allow for clients to apply specific cost models to the pattern list. This allows for DialectConversion and the GreedyPatternRewriter to share the same underlying matcher implementation. This also simplifies the plumbing necessary to support dynamic patterns.

Differential Revision: https://reviews.llvm.org/D81985
2020-06-18 13:58:47 -07:00
Alexander Belyaev
e9ac792748 [mlir] Fix some of the warnings in MLIR code.
Summary:
* extra ';' in the following files:
    mlir/lib/Dialect/Linalg/Transforms/Transforms.cpp
    mlir/lib/Dialect/Shape/IR/Shape.cpp

* base class ‘mlir::ConvertVectorToSCFBase<ConvertVectorToSCFPass>’
  should be explicitly initialized in the copy constructor [-Wextra] in
    mlir/lib/Conversion/VectorToSCF/VectorToSCF.cpp

* warning: ‘bool Expression::operator==(const Expression&) const’
  defined but not used [-Wunused-function] in
    mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-gen.cpp

Differential Revision: https://reviews.llvm.org/D81673
2020-06-11 22:18:32 +02:00
Nicolas Vasilache
56ce65e2b6 [mlir][Linalg] NFC - Cleanup debug, address post-commit review. 2020-06-05 13:02:34 -04:00
Nicolas Vasilache
e349fb70a2 [mlir][Linalg] NFC - Make markers use Identifier instead of StringRef
Summary: This removes string ownership worries by putting everything into the context and allows more constructing identifiers programmatically.

Reviewers: ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, jurahul

Tags: #mlir

Differential Revision: https://reviews.llvm.org/D81027
2020-06-03 05:52:32 -04:00
Nicolas Vasilache
91beb5176b [mlir] NFC - Add debug information for Linalg transformations.
Address post-commit review of https://reviews.llvm.org/D79518
2020-05-29 18:35:22 -04:00
MaheshRavishankar
0ed2d4c7cb [mlir][linalg] Allow promotion to use callbacks for
alloc/dealloc/copies.

Add options to LinalgPromotion to use callbacks for implementating the
allocation, deallocation of buffers used for the promoted subviews,
and to copy data into and from the original subviews to the allocated
buffers.
Also some misc. cleanup of the code.

Differential Revision: https://reviews.llvm.org/D80365
2020-05-26 21:33:57 -07:00
Nicolas Vasilache
004a3d4f56 [mlir][Linalg] Refactor linalg tiling
Summary:
This revision refactors the Linalg tiling pass to be written as pattern applications and retires the use of the folder in Linalg tiling.
In the early days, tiling was written as a pass that would create (partially) folded and canonicalized operations on the fly for better composability.
As this evolves towards composition of patterns, the pass-specific folder is counter-productive and is retired.
The tiling options struct evolves to take a tile size creation function which allows materializing tile sizes on the fly (in particular constant tile sizes). This plays better with folding and DCE.

With the folder going away in Tiling, the check on whether subviews are the same in linalg fusion needs to be more robust. This revision also implements such a check.

In the current form, there are still some canonicalizations missing due to  AffineMin/Max ops fed by scf::ForOp. These will be improved at a later time.

Differential Revision: https://reviews.llvm.org/D80267
2020-05-20 09:39:56 -04:00
Nicolas Vasilache
d12d05a731 [mlir][Linalg] Introduce a helper function for staged pattern application
Summary:
This revision introduces a helper function to allow applying rewrite patterns, interleaved with more global transformations, in a staged fashion:
1. the first stage consists of an OwningRewritePatternList. The RewritePattern in this list are applied once and in order.
2. the second stage consists of a single OwningRewritePattern that is applied greedily until convergence.
3. the third stage consists of applying a lambda, generally used for non-local transformation effects.

This allows creating custom fused transformations where patterns can be ordered and applied at a finer granularity than a sequence of traditional compiler passes.

A test that exercises these behaviors is added.

Differential Revision: https://reviews.llvm.org/D79518
2020-05-11 16:46:30 -04:00
Nicolas Vasilache
8dbbb22383 [mlir][Linalg] NFC - Refactor and simplify Promotion
Summary: This revision introduces LinalgPromotionOptions to more easily control the application of promotion patterns. It also simplifies the different entry points into Promotion in preparation for some behavior change in subsequent revisions.

Differential Revision: https://reviews.llvm.org/D79489
2020-05-11 10:44:45 -04:00
Nicolas Vasilache
307cfdf533 [mlir][Linalg] Mostly NFC - Refactor Linalg patterns and transformations.
Linalg transformations are currently exposed as DRRs.
Unfortunately RewriterGen does not play well with the line of work on named linalg ops which require variadic operands and results.
Additionally, DRR is arguably not the right abstraction to expose compositions of such patterns that don't rely on SSA use-def semantics.

This revision abandons DRRs and exposes manually written C++ patterns.

Refactorings and cleanups are performed to uniformize APIs.
This refactoring will allow replacing the currently manually specified Linalg named ops.

A collateral victim of this refactoring is the `tileAndFuse` DRR, and the one associated test, which will be revived at a later time.

Lastly, the following 2 tests do not add value and are altered:
- a dot_perm tile + interchange test does not test anything new and is removed
- a dot tile + lower to loops does not need 2-D tiling and is trimmed.
2020-05-04 11:17:37 -04:00