//===- TileUsingInterface.h - Tiling ops using TilingInterface --*- C++ -*-===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef MLIR_DIALECT_SCF_TRANSFORMS_TILEUSINGINTERFACE_H #define MLIR_DIALECT_SCF_TRANSFORMS_TILEUSINGINTERFACE_H #include "mlir/Dialect/SCF/IR/SCF.h" #include "mlir/Dialect/Tensor/Transforms/Transforms.h" #include "mlir/IR/PatternMatch.h" #include "mlir/Interfaces/LoopLikeInterface.h" #include "mlir/Interfaces/TilingInterface.h" #include "mlir/Interfaces/ViewLikeInterface.h" #include <deque> namespace mlir { class Operation; class RewriterBase; class TilingInterface; } // namespace mlir namespace mlir { namespace scf { SCFTileSizeComputationFunction; /// Options to use to control tiling. struct SCFTilingOptions { … }; /// Transformation information returned after tiling. struct SCFTilingResult { … }; /// Method to tile an op that implements the `TilingInterface` using /// `scf.for` for iterating over the tiles. FailureOr<SCFTilingResult> tileUsingSCF(RewriterBase &rewriter, TilingInterface op, const SCFTilingOptions &options); /// Options used to control tile + fuse. struct SCFTileAndFuseOptions { … }; /// Fuse the producer of the source of `candidateSliceOp` by computing the /// required slice of the producer in-place. Note that the method /// replaces the uses of `candidateSliceOp` with the tiled and fused producer /// value but does not delete the slice operation. struct SCFFuseProducerOfSliceResult { … }; std::optional<SCFFuseProducerOfSliceResult> tileAndFuseProducerOfSlice(RewriterBase &rewriter, tensor::ExtractSliceOp candidateSliceOp, MutableArrayRef<LoopLikeOpInterface> loops); /// Reconstruct the fused producer from within the tiled-and-fused code. Based /// on the slice of the producer computed in place it is possible that within /// the loop nest same slice of the producer is computed multiple times. It is /// in general not possible to recompute the value of the fused producer from /// the tiled loop code in such cases. For the cases where no slice of the /// producer is computed in a redundant fashion it is possible to reconstruct /// the value of the original producer from within the tiled loop. It is upto /// the caller to ensure that the producer is not computed redundantly within /// the tiled loop nest. For example, consider /// /// ```mlir /// %0 = linalg.matmul ins(...) outs(...) -> tensor<?x?xf32> /// %1 = linalg.matmul ins(%0, ..) outs(...) -> tensor<?x?x?f32> /// ``` /// /// If `%1` is tiled in a 2D fashion and `%0` is fused with it, the resulting IR /// is, /// /// ```mlir /// %t1_0 = scf.for .... iter_args(%arg0 = ...) { /// %t1_1 = scf.for ... iter_args(%arg1 = %arg0) { /// ... /// %t1_2 = linalg.matmul ins(...) outs(...) -> tensor<?x?xf32> /// %t1_3 = linalg.matmul ins(%t1_2, ...) /// %t1_4 = tensor.insert_slice %t1_3 into %arg1 ... /// scf.yield %t1_4 /// } /// scf.yield %t1_1 /// } /// ``` /// /// Here `%t1_2` is the same for all iterations of the inner `scf.for`. Instead /// if `%1` were tiled only along the rows, the resultant code would be /// /// ```mlir /// %t2_0 = scf.for .... iter_args(%arg0 = ...) { /// ... /// %t2_1 = linalg.matmul ins(...) outs(...) -> tensor<?x?xf32> /// %t2_2 = linalg.matmul ins(%t2_1, ...) /// %t2_3 = tensor.insert_slice %t2_2 into %arg0 ... /// scf.yield %t2_3 /// } /// ``` /// /// Here there is no intersection in the different slices of `%t2_1` computed /// across iterations of the `scf.for`. In such cases, the value of the original /// `%0` can be reconstructed from within the loop body. This is useful in cases /// where `%0` had other uses as well. If not reconstructed from within the loop /// body, uses of `%0` could not be replaced, making it still live and the /// fusion immaterial. /// /// The @param `yieldResultNumber` decides which result would be yield. If not /// given, yield all `opResult` of fused producer. /// /// The method returns the list of new slices added during the process (which /// can be used to fuse along). FailureOr<SmallVector<Operation *>> yieldReplacementForFusedProducer( RewriterBase &rewriter, tensor::ExtractSliceOp sliceOp, scf::SCFFuseProducerOfSliceResult fusedProducerInfo, MutableArrayRef<LoopLikeOpInterface> loops, ArrayRef<unsigned> yieldResultNumber = ArrayRef<unsigned>{ … }; /// Transformation information returned after tile and fuse. struct SCFTileAndFuseResult { … }; /// Method to tile and fuse a sequence of operations, by tiling the consumer /// and fusing its producers. Note that this assumes that it is valid to /// tile+fuse the producer into the innermost tiled loop. Its up to the caller /// to ensure that the tile sizes provided make this fusion valid. /// /// For example, for the following sequence /// /// ```mlir /// %0 = /// %1 = linalg.fill ... outs(%0 : ... ) /// %2 = linalg.matmul ... outs(%1 : ...) ... /// ``` /// /// it is legal to fuse the fill with the matmul only if the matmul is tiled /// along the parallel dimensions and not the reduction dimension, i.e. the tile /// size for the reduction dimension should be 0. The resulting fused /// transformation is /// /// ```mlir /// %1 = scf.for ... iter_args(%arg0 = %0) /// %2 = tensor.extract_slice %arg0 /// %3 = linalg.fill .. outs(%2 : ... ) /// %4 = linalg.matmul .. outs(%3 : ...) /// } /// ``` FailureOr<SCFTileAndFuseResult> tileConsumerAndFuseProducersUsingSCF(RewriterBase &rewriter, TilingInterface consumer, const SCFTileAndFuseOptions &options); /// Fuse the consumer of the source of `candidateSliceOp` by computing the /// required slice of the consumer in-place. Note that the method /// replaces the uses of `candidateSliceOp` with the tiled and fused consumer /// value but does not delete the slice operation. struct SCFFuseConsumerOfSliceResult { … }; FailureOr<scf::SCFFuseConsumerOfSliceResult> tileAndFuseConsumerOfSlice(RewriterBase &rewriter, Operation *candidateSliceOp); /// Method to lower an `op` that implements the `TilingInterface` to /// loops/scalars. FailureOr<SmallVector<scf::ForOp>> lowerToLoopsUsingSCFForOp(RewriterBase &rewriter, TilingInterface op); /// Transformation information returned after reduction tiling. struct SCFReductionTilingResult { … }; /// Method to tile a reduction and generate a parallel op within a serial loop. /// Each of the partial reductions are calculated in parallel. Then after the /// loop all the partial reduction are merged into a final reduction. /// For example for the following sequence /// /// ```mlir /// %0 = linalg.generic %in ["parallel", "reduction"] /// : tensor<7x9xf32> -> tensor<7xf32> /// ``` /// /// into: /// /// ```mlir /// %0 = linalg.fill ... : tensor<7x4xf32> /// %1 = scf.for ... iter_args(%arg0 = %0) /// %2 = tensor.extract_slice %arg0 : tensor<7x4xf32> -> tensor<7x?xf32> /// %3 = tensor.extract_slice %in : tensor<7x9xf32> -> tensor<7x?xf32> /// %4 = linalg.generic %2, %3 ["parallel", "parallel"] /// : tensor<7x?xf32> -> tensor<7x?xf32> /// %5 = tensor.insert_slice %3, %0[0, 0] : tensor<7x4xf32> /// } /// %6 = linalg.generic %1 ["parallel", "reduction"] /// : tensor<7x4xf32> -> tensor<7xf32> /// ``` FailureOr<scf::SCFReductionTilingResult> tileReductionUsingScf(RewriterBase &b, PartialReductionOpInterface op, ArrayRef<OpFoldResult> tileSize); } // namespace scf } // namespace mlir #endif // MLIR_DIALECT_SCF_TRANSFORMS_TILEUSINGINTERFACE_H