[Mlir-commits] [mlir] [mlir][vector] Remove redundant shape_cast(shape_cast(x)) pattern (PR #135447)
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llvmlistbot at llvm.org
Mon Apr 14 11:44:47 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-mlir
Author: James Newling (newling)
<details>
<summary>Changes</summary>
This PR removes one OpRewritePattern `shape_cast(shape_cast(x)) -> x` that is already handled by `ShapeCastOp::fold`.
Note that this might affect downstream users who indirectly call `populateShapeCastFoldingPatterns(RewritePatternSet &patterns, PatternBenefit)` and then use `patterns` with a `GreedyRewriteConfig config` that has `config.fold = false`. (only user I've checked is IREE, that never uses config.fold = false).
---
Full diff: https://github.com/llvm/llvm-project/pull/135447.diff
4 Files Affected:
- (modified) mlir/include/mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h (-4)
- (modified) mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp (-2)
- (modified) mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp (-2)
- (modified) mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp (+1-67)
``````````diff
diff --git a/mlir/include/mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h b/mlir/include/mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h
index 7de4a6a315750..ce97847172197 100644
--- a/mlir/include/mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h
+++ b/mlir/include/mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h
@@ -306,10 +306,6 @@ void populateVectorUnrollPatterns(RewritePatternSet &patterns,
const UnrollVectorOptions &options,
PatternBenefit benefit = 1);
-/// Collect a set of vector.shape_cast folding patterns.
-void populateShapeCastFoldingPatterns(RewritePatternSet &patterns,
- PatternBenefit benefit = 1);
-
/// Collect a set of leading one dimension removal patterns.
///
/// These patterns insert vector.shape_cast to remove leading one dimensions
diff --git a/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp b/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp
index fda3baf3aa390..68a44ea889470 100644
--- a/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp
+++ b/mlir/lib/Dialect/Vector/Transforms/VectorDropLeadUnitDim.cpp
@@ -8,7 +8,6 @@
#include <numeric>
-#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/Utils/StructuredOpsUtils.h"
#include "mlir/Dialect/Vector/IR/VectorOps.h"
#include "mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h"
@@ -577,5 +576,4 @@ void mlir::vector::populateCastAwayVectorLeadingOneDimPatterns(
CastAwayConstantMaskLeadingOneDim, CastAwayTransferReadLeadingOneDim,
CastAwayTransferWriteLeadingOneDim, CastAwayElementwiseLeadingOneDim,
CastAwayContractionLeadingOneDim>(patterns.getContext(), benefit);
- populateShapeCastFoldingPatterns(patterns, benefit);
}
diff --git a/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp b/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp
index 62dfd439b0ad1..999fb9c415886 100644
--- a/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp
+++ b/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp
@@ -976,7 +976,6 @@ void mlir::vector::populateVectorTransferDropUnitDimsPatterns(
patterns
.add<TransferReadDropUnitDimsPattern, TransferWriteDropUnitDimsPattern>(
patterns.getContext(), benefit);
- populateShapeCastFoldingPatterns(patterns);
}
void mlir::vector::populateFlattenVectorTransferPatterns(
@@ -985,6 +984,5 @@ void mlir::vector::populateFlattenVectorTransferPatterns(
patterns.add<FlattenContiguousRowMajorTransferReadPattern,
FlattenContiguousRowMajorTransferWritePattern>(
patterns.getContext(), targetVectorBitwidth, benefit);
- populateShapeCastFoldingPatterns(patterns, benefit);
populateDropUnitDimWithShapeCastPatterns(patterns, benefit);
}
diff --git a/mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp b/mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp
index d50d5fe96f49a..89839d0440d3c 100644
--- a/mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp
+++ b/mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp
@@ -16,36 +16,24 @@
#include <cstdint>
#include <functional>
#include <optional>
-#include <type_traits>
-#include "mlir/Dialect/Affine/IR/AffineOps.h"
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/Arith/Utils/Utils.h"
-#include "mlir/Dialect/Linalg/IR/Linalg.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/Dialect/SCF/IR/SCF.h"
-#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "mlir/Dialect/Utils/IndexingUtils.h"
#include "mlir/Dialect/Utils/StructuredOpsUtils.h"
#include "mlir/Dialect/Vector/IR/VectorOps.h"
#include "mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h"
#include "mlir/Dialect/Vector/Utils/VectorUtils.h"
-#include "mlir/IR/BuiltinAttributeInterfaces.h"
#include "mlir/IR/BuiltinTypes.h"
-#include "mlir/IR/ImplicitLocOpBuilder.h"
#include "mlir/IR/Location.h"
#include "mlir/IR/Matchers.h"
#include "mlir/IR/PatternMatch.h"
#include "mlir/IR/TypeUtilities.h"
-#include "mlir/Interfaces/VectorInterfaces.h"
-#include "llvm/ADT/DenseSet.h"
-#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/STLExtras.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
#include "llvm/Support/FormatVariadic.h"
-#include "llvm/Support/raw_ostream.h"
#define DEBUG_TYPE "vector-to-vector"
@@ -71,54 +59,6 @@ static std::optional<int64_t> getResultIndex(AffineMap map, int64_t index) {
namespace {
-/// ShapeCastOpFolder folds cancelling ShapeCastOps away.
-//
-// Example:
-//
-// The following MLIR with cancelling ShapeCastOps:
-//
-// %0 = source : vector<5x4x2xf32>
-// %1 = shape_cast %0 : vector<5x4x2xf32> to vector<20x2xf32>
-// %2 = shape_cast %1 : vector<20x2xf32> to vector<5x4x2xf32>
-// %3 = user %2 : vector<5x4x2xf32>
-//
-// Should canonicalize to the following:
-//
-// %0 = source : vector<5x4x2xf32>
-// %1 = user %0 : vector<5x4x2xf32>
-//
-struct ShapeCastOpFolder : public OpRewritePattern<vector::ShapeCastOp> {
- using OpRewritePattern::OpRewritePattern;
-
- LogicalResult matchAndRewrite(vector::ShapeCastOp shapeCastOp,
- PatternRewriter &rewriter) const override {
- // Check if 'shapeCastOp' has vector source/result type.
- auto sourceVectorType =
- dyn_cast_or_null<VectorType>(shapeCastOp.getSource().getType());
- auto resultVectorType =
- dyn_cast_or_null<VectorType>(shapeCastOp.getResult().getType());
- if (!sourceVectorType || !resultVectorType)
- return failure();
-
- // Check if shape cast op source operand is also a shape cast op.
- auto sourceShapeCastOp = dyn_cast_or_null<vector::ShapeCastOp>(
- shapeCastOp.getSource().getDefiningOp());
- if (!sourceShapeCastOp)
- return failure();
- auto operandSourceVectorType =
- cast<VectorType>(sourceShapeCastOp.getSource().getType());
- auto operandResultVectorType = sourceShapeCastOp.getType();
-
- // Check if shape cast operations invert each other.
- if (operandSourceVectorType != resultVectorType ||
- operandResultVectorType != sourceVectorType)
- return failure();
-
- rewriter.replaceOp(shapeCastOp, sourceShapeCastOp.getSource());
- return success();
- }
-};
-
/// Convert MulIOp/MulFOp + MultiDimReductionOp<add> into ContractionOp.
/// Ex:
/// ```
@@ -2113,11 +2053,6 @@ void mlir::vector::populateVectorMaskMaterializationPatterns(
patterns.add<FoldI1Select>(patterns.getContext(), benefit);
}
-void mlir::vector::populateShapeCastFoldingPatterns(RewritePatternSet &patterns,
- PatternBenefit benefit) {
- patterns.add<ShapeCastOpFolder>(patterns.getContext(), benefit);
-}
-
void mlir::vector::populateDropUnitDimWithShapeCastPatterns(
RewritePatternSet &patterns, PatternBenefit benefit) {
// TODO: Consider either:
@@ -2126,8 +2061,7 @@ void mlir::vector::populateDropUnitDimWithShapeCastPatterns(
// * better naming to distinguish this and
// populateVectorTransferCollapseInnerMostContiguousDimsPatterns.
patterns.add<DropUnitDimFromElementwiseOps, DropUnitDimsFromScfForOp,
- DropUnitDimsFromTransposeOp, ShapeCastOpFolder>(
- patterns.getContext(), benefit);
+ DropUnitDimsFromTransposeOp>(patterns.getContext(), benefit);
}
void mlir::vector::populateBubbleVectorBitCastOpPatterns(
``````````
</details>
https://github.com/llvm/llvm-project/pull/135447
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