| 1 | //===- TestAffineLoopUnswitching.cpp - Test affine if/else hoisting -------===// |
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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 | // This file implements a pass to hoist affine if/else structures. |
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| 10 | // |
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| 11 | //===----------------------------------------------------------------------===// |
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| 12 | |
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| 13 | #include "mlir/Dialect/Affine/Analysis/Utils.h" |
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| 14 | #include "mlir/Dialect/Affine/IR/AffineOps.h" |
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| 15 | #include "mlir/Dialect/Affine/Utils.h" |
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| 16 | #include "mlir/Pass/Pass.h" |
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| 17 | #include "mlir/Transforms/Passes.h" |
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| 18 | |
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| 19 | #define PASS_NAME "test-affine-loop-unswitch" |
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| 20 | |
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| 21 | using namespace mlir; |
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| 22 | using namespace mlir::affine; |
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| 23 | |
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| 24 | namespace { |
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| 25 | |
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| 26 | /// This pass applies the permutation on the first maximal perfect nest. |
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| 27 | struct TestAffineLoopUnswitching |
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| 28 | : public PassWrapper<TestAffineLoopUnswitching, OperationPass<>> { |
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| 29 | MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(TestAffineLoopUnswitching) |
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| 30 | |
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| 31 | StringRef getArgument() const final { return PASS_NAME; } |
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| 32 | StringRef getDescription() const final { |
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| 33 | return "Tests affine loop unswitching / if/else hoisting" ; |
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| 34 | } |
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| 35 | TestAffineLoopUnswitching() = default; |
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| 36 | TestAffineLoopUnswitching(const TestAffineLoopUnswitching &pass) = default; |
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| 37 | |
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| 38 | void runOnOperation() override; |
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| 39 | |
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| 40 | /// The maximum number of iterations to run this for. |
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| 41 | constexpr static unsigned kMaxIterations = 5; |
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| 42 | }; |
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| 43 | |
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| 44 | } // namespace |
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| 45 | |
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| 46 | void TestAffineLoopUnswitching::runOnOperation() { |
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| 47 | // Each hoisting invalidates a lot of IR around. Just stop the walk after the |
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| 48 | // first if/else hoisting, and repeat until no more hoisting can be done, or |
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| 49 | // the maximum number of iterations have been run. |
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| 50 | Operation *op = getOperation(); |
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| 51 | unsigned i = 0; |
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| 52 | do { |
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| 53 | auto walkFn = [](AffineIfOp op) { |
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| 54 | return succeeded(hoistAffineIfOp(op)) ? WalkResult::interrupt() |
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| 55 | : WalkResult::advance(); |
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| 56 | }; |
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| 57 | if (op->walk(walkFn).wasInterrupted()) |
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| 58 | break; |
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| 59 | } while (++i < kMaxIterations); |
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| 60 | } |
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| 61 | |
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| 62 | namespace mlir { |
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| 63 | void registerTestAffineLoopUnswitchingPass() { |
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| 64 | PassRegistration<TestAffineLoopUnswitching>(); |
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| 65 | } |
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| 66 | } // namespace mlir |
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| 67 | |
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