1 //===- ConcatOpPatterns.cpp - Patterns related to tensor.concat lowering --===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "mlir/Dialect/Affine/IR/AffineOps.h" 10 #include "mlir/Dialect/Arith/IR/Arith.h" 11 #include "mlir/Dialect/Arith/Utils/Utils.h" 12 #include "mlir/Dialect/Tensor/IR/Tensor.h" 13 #include "mlir/Dialect/Tensor/Transforms/Transforms.h" 14 #include "mlir/IR/PatternMatch.h" 15 16 using namespace mlir; 17 using namespace mlir::tensor; 18 19 namespace { 20 21 /// Decompose `tensor.concat` into `tensor.empty` and a chain of slice inserts. 22 /// 23 /// %concat = tensor.concat dim(1) %0, %1 : 24 /// (tensor<2x3xf32>, tensor<2x4xf32>) -> tensor<2x7xf32> 25 /// 26 /// Becomes 27 /// 28 /// %empty = tensor.empty() : tensor<2x7xf32> 29 /// %insert0 = tensor.insert_slice %0 into %empty[0, 0][2, 3][1, 1] 30 /// %concat = tensor.insert_slice %1 into %insert0[0, 3][2, 4][1, 1] 31 struct DecomposeTensorConcatOp : public OpRewritePattern<ConcatOp> { 32 using OpRewritePattern<ConcatOp>::OpRewritePattern; 33 34 LogicalResult matchAndRewrite(ConcatOp concatOp, 35 PatternRewriter &rewriter) const override { 36 FailureOr<SmallVector<Value>> decomposed = 37 concatOp.decomposeOperation(rewriter); 38 if (failed(decomposed)) { 39 return rewriter.notifyMatchFailure( 40 concatOp, "failed to get the decomposed insert slices"); 41 } 42 rewriter.replaceOp(concatOp, decomposed.value()[0]); 43 return success(); 44 } 45 }; 46 47 } // namespace 48 49 void mlir::tensor::populateDecomposeTensorConcatPatterns( 50 RewritePatternSet &patterns) { 51 patterns.add<DecomposeTensorConcatOp>(patterns.getContext()); 52 } 53