a70aa7bb0d
This has been a major TODO for a very long time, and is necessary for establishing a proper dialect-free dependency layering for the Transforms library. Code was moved to effectively two main locations: * Affine/ There was quite a bit of affine dialect related code in Transforms/ do to historical reasons (of a time way into MLIR's past). The following headers were moved to: Transforms/LoopFusionUtils.h -> Dialect/Affine/LoopFusionUtils.h Transforms/LoopUtils.h -> Dialect/Affine/LoopUtils.h Transforms/Utils.h -> Dialect/Affine/Utils.h The following transforms were also moved: AffineLoopFusion, AffinePipelineDataTransfer, LoopCoalescing * SCF/ Only one SCF pass was in Transforms/ (likely accidentally placed here): ParallelLoopCollapsing The SCF specific utilities in LoopUtils have been moved to SCF/Utils.h * Misc: mlir::moveLoopInvariantCode was also moved to LoopLikeInterface.h given that it is a simple utility defined in terms of LoopLikeOpInterface. Differential Revision: https://reviews.llvm.org/D117848
72 lines
2.5 KiB
C++
72 lines
2.5 KiB
C++
//===- TestConstantFold.cpp - Pass to test constant folding ---------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "mlir/Pass/Pass.h"
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#include "mlir/Transforms/FoldUtils.h"
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#include "mlir/Transforms/Passes.h"
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using namespace mlir;
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namespace {
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/// Simple constant folding pass.
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struct TestConstantFold
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: public PassWrapper<TestConstantFold, OperationPass<FuncOp>> {
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StringRef getArgument() const final { return "test-constant-fold"; }
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StringRef getDescription() const final {
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return "Test operation constant folding";
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}
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// All constants in the function post folding.
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SmallVector<Operation *, 8> existingConstants;
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void foldOperation(Operation *op, OperationFolder &helper);
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void runOnOperation() override;
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};
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} // namespace
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void TestConstantFold::foldOperation(Operation *op, OperationFolder &helper) {
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auto processGeneratedConstants = [this](Operation *op) {
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existingConstants.push_back(op);
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};
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// Attempt to fold the specified operation, including handling unused or
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// duplicated constants.
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(void)helper.tryToFold(op, processGeneratedConstants);
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}
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// For now, we do a simple top-down pass over a function folding constants. We
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// don't handle conditional control flow, block arguments, folding conditional
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// branches, or anything else fancy.
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void TestConstantFold::runOnOperation() {
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existingConstants.clear();
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// Collect and fold the operations within the function.
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SmallVector<Operation *, 8> ops;
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getOperation().walk([&](Operation *op) { ops.push_back(op); });
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// Fold the constants in reverse so that the last generated constants from
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// folding are at the beginning. This creates somewhat of a linear ordering to
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// the newly generated constants that matches the operation order and improves
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// the readability of test cases.
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OperationFolder helper(&getContext());
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for (Operation *op : llvm::reverse(ops))
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foldOperation(op, helper);
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// By the time we are done, we may have simplified a bunch of code, leaving
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// around dead constants. Check for them now and remove them.
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for (auto *cst : existingConstants) {
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if (cst->use_empty())
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cst->erase();
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}
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}
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namespace mlir {
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namespace test {
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void registerTestConstantFold() { PassRegistration<TestConstantFold>(); }
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} // namespace test
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} // namespace mlir
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