1//===- OptReductionPass.cpp - Optimization Reduction Pass Wrapper ---------===//
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// This file defines the Opt Reduction Pass Wrapper. It creates a MLIR pass to
10// run any optimization pass within it and only replaces the output module with
11// the transformed version if it is smaller and interesting.
12//
13//===----------------------------------------------------------------------===//
14
15#include "mlir/Pass/PassManager.h"
16#include "mlir/Pass/PassRegistry.h"
17#include "mlir/Reducer/Passes.h"
18#include "mlir/Reducer/Tester.h"
19
20#include "llvm/Support/Debug.h"
21
22namespace mlir {
23#define GEN_PASS_DEF_OPTREDUCTIONPASS
24#include "mlir/Reducer/Passes.h.inc"
25} // namespace mlir
26
27#define DEBUG_TYPE "mlir-reduce"
28
29using namespace mlir;
30
31namespace {
32
33class OptReductionPass : public impl::OptReductionPassBase<OptReductionPass> {
34public:
35 using Base::Base;
36
37 /// Runs the pass instance in the pass pipeline.
38 void runOnOperation() override;
39};
40
41} // namespace
42
43/// Runs the pass instance in the pass pipeline.
44void OptReductionPass::runOnOperation() {
45 LLVM_DEBUG(llvm::dbgs() << "\nOptimization Reduction pass: ");
46
47 Tester test(testerName, testerArgs);
48
49 ModuleOp module = this->getOperation();
50 ModuleOp moduleVariant = module.clone();
51
52 OpPassManager passManager("builtin.module");
53 if (failed(parsePassPipeline(optPass, passManager))) {
54 module.emitError() << "\nfailed to parse pass pipeline";
55 return signalPassFailure();
56 }
57
58 std::pair<Tester::Interestingness, int> original = test.isInteresting(module);
59 if (original.first != Tester::Interestingness::True) {
60 module.emitError() << "\nthe original input is not interested";
61 return signalPassFailure();
62 }
63
64 // Temporarily push the variant under the main module and execute the pipeline
65 // on it.
66 module.getBody()->push_back(moduleVariant);
67 LogicalResult pipelineResult = runPipeline(passManager, moduleVariant);
68 moduleVariant->remove();
69
70 if (failed(Result: pipelineResult)) {
71 module.emitError() << "\nfailed to run pass pipeline";
72 return signalPassFailure();
73 }
74
75 std::pair<Tester::Interestingness, int> reduced =
76 test.isInteresting(moduleVariant);
77
78 if (reduced.first == Tester::Interestingness::True &&
79 reduced.second < original.second) {
80 module.getBody()->clear();
81 module.getBody()->getOperations().splice(
82 module.getBody()->begin(), moduleVariant.getBody()->getOperations());
83 LLVM_DEBUG(llvm::dbgs() << "\nSuccessful Transformed version\n\n");
84 } else {
85 LLVM_DEBUG(llvm::dbgs() << "\nUnsuccessful Transformed version\n\n");
86 }
87
88 moduleVariant->destroy();
89
90 LLVM_DEBUG(llvm::dbgs() << "Pass Complete\n\n");
91}
92

source code of mlir/lib/Reducer/OptReductionPass.cpp