| 1 | //===- LinearTransform.h - MLIR LinearTransform Class -----------*- C++ -*-===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // Support for linear transforms and applying them to an IntegerRelation. |
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| 10 | // |
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| 11 | //===----------------------------------------------------------------------===// |
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| 12 | |
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| 13 | #ifndef MLIR_ANALYSIS_PRESBURGER_LINEARTRANSFORM_H |
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| 14 | #define MLIR_ANALYSIS_PRESBURGER_LINEARTRANSFORM_H |
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| 15 | |
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| 16 | #include "mlir/Analysis/Presburger/IntegerRelation.h" |
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| 17 | #include "mlir/Analysis/Presburger/Matrix.h" |
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| 18 | #include "llvm/ADT/SmallVector.h" |
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| 19 | |
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| 20 | namespace mlir { |
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| 21 | namespace presburger { |
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| 22 | |
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| 23 | class LinearTransform { |
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| 24 | public: |
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| 25 | explicit LinearTransform(IntMatrix &&oMatrix); |
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| 26 | explicit LinearTransform(const IntMatrix &oMatrix); |
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| 27 | |
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| 28 | // Returns a linear transform T such that MT is M in column echelon form. |
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| 29 | // Also returns the number of non-zero columns in MT. |
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| 30 | // |
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| 31 | // Specifically, T is such that in every column the first non-zero row is |
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| 32 | // strictly below that of the previous column, and all columns which have only |
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| 33 | // zeros are at the end. |
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| 34 | static std::pair<unsigned, LinearTransform> |
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| 35 | makeTransformToColumnEchelon(const IntMatrix &m); |
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| 36 | |
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| 37 | // Returns an IntegerRelation having a constraint vector vT for every |
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| 38 | // constraint vector v in rel, where T is this transform. |
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| 39 | IntegerRelation applyTo(const IntegerRelation &rel) const; |
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| 40 | |
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| 41 | // The given vector is interpreted as a row vector v. Post-multiply v with |
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| 42 | // this transform, say T, and return vT. |
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| 43 | SmallVector<MPInt, 8> preMultiplyWithRow(ArrayRef<MPInt> rowVec) const { |
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| 44 | return matrix.preMultiplyWithRow(rowVec); |
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| 45 | } |
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| 46 | |
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| 47 | // The given vector is interpreted as a column vector v. Pre-multiply v with |
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| 48 | // this transform, say T, and return Tv. |
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| 49 | SmallVector<MPInt, 8> postMultiplyWithColumn(ArrayRef<MPInt> colVec) const { |
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| 50 | return matrix.postMultiplyWithColumn(colVec); |
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| 51 | } |
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| 52 | |
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| 53 | private: |
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| 54 | IntMatrix matrix; |
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| 55 | }; |
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| 56 | |
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| 57 | } // namespace presburger |
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| 58 | } // namespace mlir |
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| 59 | |
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| 60 | #endif // MLIR_ANALYSIS_PRESBURGER_LINEARTRANSFORM_H |
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| 61 | |
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