PointsToGraphTests.cpp

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/*
 * Copyright 2023 Nico Reißmann <nico.reissmann@gmail.com>
 * See COPYING for terms of redistribution.
 */
 
#include <gtest/gtest.h>
 
#include <jlm/llvm/ir/operators/alloca.hpp>
#include <jlm/llvm/ir/operators/IntegerOperations.hpp>
#include <jlm/llvm/ir/operators/operators.hpp>
#include <jlm/llvm/opt/alias-analyses/PointsToAnalysis.hpp>
#include <jlm/llvm/opt/alias-analyses/PointsToGraph.hpp>
#include <jlm/llvm/TestRvsdgs.hpp>
#include <jlm/rvsdg/delta.hpp>
#include <jlm/rvsdg/simple-node.hpp>
#include <jlm/util/Statistics.hpp>
 
class TestAnalysis final : public jlm::llvm::aa::PointsToAnalysis
{
public:
  std::unique_ptr<jlm::llvm::aa::PointsToGraph>
  Analyze(const jlm::rvsdg::RvsdgModule & rvsdgModule, jlm::util::StatisticsCollector &) override
  {
    pointsToGraph_ = jlm::llvm::aa::PointsToGraph::create();
 
    AnalyzeImports(rvsdgModule.Rvsdg());
    AnalyzeRegion(rvsdgModule.Rvsdg().GetRootRegion());
 
    return std::move(pointsToGraph_);
  }
 
  std::unique_ptr<jlm::llvm::aa::PointsToGraph>
  Analyze(const jlm::llvm::LlvmRvsdgModule & rvsdgModule)
  {
    jlm::util::StatisticsCollector statisticsCollector;
    return Analyze(rvsdgModule, statisticsCollector);
  }
 
  static std::unique_ptr<jlm::llvm::aa::PointsToGraph>
  CreateAndAnalyze(const jlm::llvm::LlvmRvsdgModule & rvsdgModule)
  {
    TestAnalysis analysis;
    return analysis.Analyze(rvsdgModule);
  }
 
private:
  void
  AnalyzeRegion(jlm::rvsdg::Region & region)
  {
    using namespace jlm::llvm;
 
    for (auto & node : region.Nodes())
    {
      if (jlm::rvsdg::is<AllocaOperation>(&node))
      {
        auto simpleNode = jlm::util::assertedCast<jlm::rvsdg::SimpleNode>(&node);
        auto ptgAllocaNode = pointsToGraph_->addNodeForAlloca(*simpleNode, false);
        auto ptgRegisterNode = pointsToGraph_->addNodeForRegisters();
        pointsToGraph_->mapRegisterToNode(*node.output(0), ptgRegisterNode);
        pointsToGraph_->addTarget(ptgRegisterNode, ptgAllocaNode);
      }
      else if (jlm::rvsdg::is<MallocOperation>(&node))
      {
        auto simpleNode = jlm::util::assertedCast<jlm::rvsdg::SimpleNode>(&node);
        auto ptgMallocNode = pointsToGraph_->addNodeForMalloc(*simpleNode, true);
        auto ptgRegisterNode = pointsToGraph_->addNodeForRegisters();
        pointsToGraph_->mapRegisterToNode(MallocOperation::addressOutput(node), ptgRegisterNode);
        pointsToGraph_->addTarget(ptgRegisterNode, ptgMallocNode);
      }
      else if (auto deltaNode = dynamic_cast<const jlm::rvsdg::DeltaNode *>(&node))
      {
        auto ptgDeltaNode = pointsToGraph_->addNodeForDelta(*deltaNode, true);
        auto ptgRegisterNode = pointsToGraph_->addNodeForRegisters();
        pointsToGraph_->mapRegisterToNode(*node.output(0), ptgRegisterNode);
        pointsToGraph_->addTarget(ptgRegisterNode, ptgDeltaNode);
 
        AnalyzeRegion(*deltaNode->subregion());
      }
      else if (auto lambdaNode = dynamic_cast<const jlm::rvsdg::LambdaNode *>(&node))
      {
        auto ptgLambdaNode = pointsToGraph_->addNodeForLambda(*lambdaNode, true);
        auto ptgRegisterNode = pointsToGraph_->addNodeForRegisters();
        pointsToGraph_->mapRegisterToNode(*node.output(0), ptgRegisterNode);
        pointsToGraph_->addTarget(ptgRegisterNode, ptgLambdaNode);
 
        AnalyzeRegion(*lambdaNode->subregion());
      }
    }
  }
 
  void
  AnalyzeImports(const jlm::rvsdg::Graph & rvsdg)
  {
    using namespace jlm::llvm;
 
    auto & rootRegion = rvsdg.GetRootRegion();
    for (size_t n = 0; n < rootRegion.narguments(); n++)
    {
      auto & graphImport = *jlm::util::assertedCast<const LlvmGraphImport>(rootRegion.argument(n));
 
      const auto ptgImportNode = pointsToGraph_->addNodeForImport(graphImport, true);
      const auto ptgRegisterNode = pointsToGraph_->addNodeForRegisters();
      pointsToGraph_->mapRegisterToNode(graphImport, ptgRegisterNode);
      pointsToGraph_->addTarget(ptgRegisterNode, ptgImportNode);
    }
  }
 
  std::unique_ptr<jlm::llvm::aa::PointsToGraph> pointsToGraph_;
};
 
TEST(PointsToGraphTests, TestNodeIterators)
{
  // Arrange
  jlm::llvm::AllMemoryNodesTest test;
  auto pointsToGraph = TestAnalysis::CreateAndAnalyze(test.module());
 
  using NodeIndex = jlm::llvm::aa::PointsToGraph::NodeIndex;
  using NodeKind = jlm::llvm::aa::PointsToGraph::NodeKind;
 
  // Act and Assert
  EXPECT_EQ(pointsToGraph->numImportNodes(), 1u);
  for (auto importNode : pointsToGraph->importNodes())
  {
    EXPECT_EQ(pointsToGraph->getNodeKind(importNode), NodeKind::ImportNode);
    EXPECT_EQ(&pointsToGraph->getImportForNode(importNode), &test.GetImportOutput());
  }
 
  EXPECT_EQ(pointsToGraph->numLambdaNodes(), 1u);
  for (auto & lambdaNode : pointsToGraph->lambdaNodes())
  {
    EXPECT_EQ(pointsToGraph->getNodeKind(lambdaNode), NodeKind::LambdaNode);
    EXPECT_EQ(&pointsToGraph->getLambdaForNode(lambdaNode), &test.GetLambdaNode());
  }
 
  EXPECT_EQ(pointsToGraph->numDeltaNodes(), 1u);
  for (auto & deltaNode : pointsToGraph->deltaNodes())
  {
    EXPECT_EQ(pointsToGraph->getNodeKind(deltaNode), NodeKind::DeltaNode);
    EXPECT_EQ(&pointsToGraph->getDeltaForNode(deltaNode), &test.GetDeltaNode());
  }
 
  EXPECT_EQ(pointsToGraph->numAllocaNodes(), 1u);
  for (auto & allocaNode : pointsToGraph->allocaNodes())
  {
    EXPECT_EQ(pointsToGraph->getNodeKind(allocaNode), NodeKind::AllocaNode);
    EXPECT_EQ(&pointsToGraph->getAllocaForNode(allocaNode), &test.GetAllocaNode());
  }
 
  EXPECT_EQ(pointsToGraph->numMallocNodes(), 1u);
  for (auto & mallocNode : pointsToGraph->mallocNodes())
  {
    EXPECT_EQ(pointsToGraph->getNodeKind(mallocNode), NodeKind::MallocNode);
    EXPECT_EQ(&pointsToGraph->getMallocForNode(mallocNode), &test.GetMallocNode());
  }
 
  // Check that each register is seen
  EXPECT_EQ(pointsToGraph->numRegisterNodes(), 5u);
  jlm::util::HashSet<NodeIndex> seenRegisterNodes;
  for (auto & registerNode : pointsToGraph->registerNodes())
  {
    EXPECT_EQ(pointsToGraph->getNodeKind(registerNode), NodeKind::RegisterNode);
    EXPECT_EQ(pointsToGraph->getExplicitTargets(registerNode).Size(), 1u);
    seenRegisterNodes.insert(registerNode);
  }
  EXPECT_EQ(seenRegisterNodes.Size(), 5u);
 
  const auto ptgImportRegister = pointsToGraph->getNodeForRegister(test.GetImportOutput());
  EXPECT_TRUE(seenRegisterNodes.Contains(ptgImportRegister));
  const auto ptgLambdaRegister = pointsToGraph->getNodeForRegister(test.GetLambdaOutput());
  EXPECT_TRUE(seenRegisterNodes.Contains(ptgLambdaRegister));
  const auto ptgDeltaRegister = pointsToGraph->getNodeForRegister(test.GetDeltaOutput());
  EXPECT_TRUE(seenRegisterNodes.Contains(ptgDeltaRegister));
  const auto ptgAllocaRegister = pointsToGraph->getNodeForRegister(test.GetAllocaOutput());
  EXPECT_TRUE(seenRegisterNodes.Contains(ptgAllocaRegister));
  const auto ptgMallocRegister = pointsToGraph->getNodeForRegister(test.GetMallocOutput());
  EXPECT_TRUE(seenRegisterNodes.Contains(ptgMallocRegister));
 
  // Check that the target of each register node is correct
  const auto ptgImportNode = pointsToGraph->getNodeForImport(test.GetImportOutput());
  EXPECT_TRUE(pointsToGraph->getExplicitTargets(ptgImportRegister).Contains(ptgImportNode));
  const auto ptgLambdaNode = pointsToGraph->getNodeForLambda(test.GetLambdaNode());
  EXPECT_TRUE(pointsToGraph->getExplicitTargets(ptgLambdaRegister).Contains(ptgLambdaNode));
  const auto ptgDeltaNode = pointsToGraph->getNodeForDelta(test.GetDeltaNode());
  EXPECT_TRUE(pointsToGraph->getExplicitTargets(ptgDeltaRegister).Contains(ptgDeltaNode));
  const auto ptgAllocaNode = pointsToGraph->getNodeForAlloca(test.GetAllocaNode());
  EXPECT_TRUE(pointsToGraph->getExplicitTargets(ptgAllocaRegister).Contains(ptgAllocaNode));
  const auto ptgMallocNode = pointsToGraph->getNodeForMalloc(test.GetMallocNode());
  EXPECT_TRUE(pointsToGraph->getExplicitTargets(ptgMallocRegister).Contains(ptgMallocNode));
}
 
TEST(PointsToGraphTests, TestIsSupergraphOf)
{
  using namespace jlm::llvm::aa;
  auto graph0 = PointsToGraph::create();
  auto graph1 = PointsToGraph::create();
 
  // Empty graphs are identical, and are both subgraphs of each other
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  jlm::llvm::AllMemoryNodesTest rvsdg;
  rvsdg.InitializeTest();
 
  // Adding an alloca node to only graph0, makes graph1 NOT a subgraph
  const auto alloca0 = graph0->addNodeForAlloca(rvsdg.GetAllocaNode(), false);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_FALSE(graph1->isSupergraphOf(*graph0));
 
  // Adding a corresponding alloca node to graph1, they are now equal
  const auto alloca1 = graph1->addNodeForAlloca(rvsdg.GetAllocaNode(), false);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  // Adding register0 makes graph1 NOT a subgraph
  const auto register0 = graph0->addNodeForRegisters();
  graph0->mapRegisterToNode(rvsdg.GetAllocaOutput(), register0);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_FALSE(graph1->isSupergraphOf(*graph0));
 
  // Adding register1 that covers both the alloca and delta outputs makes graph0 NOT a subgraph
  const auto register1 = graph1->addNodeForRegisters();
  graph1->mapRegisterToNode(rvsdg.GetAllocaOutput(), register1);
  graph1->mapRegisterToNode(rvsdg.GetDeltaOutput(), register1);
  EXPECT_FALSE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  // Adding a deltaRegister0 to make the graphs identical again
  const auto deltaRegister0 = graph0->addNodeForRegisters();
  graph0->mapRegisterToNode(rvsdg.GetDeltaOutput(), deltaRegister0);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  // Adding an edge from register0 to the alloca makes graph1 NOT a subgraph
  graph0->addTarget(register0, alloca0);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_FALSE(graph1->isSupergraphOf(*graph0));
 
  // By adding an edge from register1 (delta+alloca output), graph0 is now a subgraph of graph1
  graph1->addTarget(register1, alloca1);
  EXPECT_FALSE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  // To make them identical, the both the delta and alloca registers must point to the alloca
  graph0->addTarget(deltaRegister0, alloca0);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  // Adding an edge from alloca0 to external that is NOT in graph1
  graph0->markAsTargetsAllExternallyAvailable(alloca0);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_FALSE(graph1->isSupergraphOf(*graph0));
 
  // Adding the same edge to alloca1 makes the graphs identical again
  graph1->markAsTargetsAllExternallyAvailable(alloca1);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  // Finally test all the other memory node types
  graph0->addNodeForDelta(rvsdg.GetDeltaNode(), false);
  graph1->addNodeForDelta(rvsdg.GetDeltaNode(), false);
  const auto import0 = graph0->addNodeForImport(rvsdg.GetImportOutput(), true);
  const auto import1 = graph1->addNodeForImport(rvsdg.GetImportOutput(), true);
  const auto lambda0 = graph0->addNodeForLambda(rvsdg.GetLambdaNode(), false);
  const auto lambda1 = graph1->addNodeForLambda(rvsdg.GetLambdaNode(), false);
  const auto malloc0 = graph0->addNodeForMalloc(rvsdg.GetMallocNode(), false);
  const auto malloc1 = graph1->addNodeForMalloc(rvsdg.GetMallocNode(), false);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
 
  // Add some arbitrary edges between memory nodes
  graph0->addTarget(malloc0, import0);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_FALSE(graph1->isSupergraphOf(*graph0));
 
  graph1->addTarget(import1, lambda1);
  EXPECT_FALSE(graph0->isSupergraphOf(*graph1));
 
  // Make them equal again by adding the same edges to the opposite graph
  graph1->addTarget(malloc1, import1);
  graph0->addTarget(import0, lambda0);
  EXPECT_TRUE(graph0->isSupergraphOf(*graph1));
  EXPECT_TRUE(graph1->isSupergraphOf(*graph0));
}
 
TEST(PointsToGraphTests, testMemoryNodeSize)
{
  using namespace jlm::llvm;
 
  {
    // Arrange
    jlm::llvm::DeltaTest3 test;
    test.InitializeTest();
 
    auto ptg = aa::PointsToGraph::create();
    const auto deltaG1 = ptg->addNodeForDelta(test.DeltaG1(), false);
    const auto deltaG2 = ptg->addNodeForDelta(test.DeltaG2(), false);
    const auto f = ptg->addNodeForLambda(test.LambdaF(), false);
 
    // Assert
    EXPECT_EQ(ptg->tryGetNodeSize(deltaG1), 4);
    EXPECT_EQ(ptg->tryGetNodeSize(deltaG2), 8);
    EXPECT_EQ(ptg->tryGetNodeSize(f), 0);
  }
 
  {
    // Arrange 2
    jlm::llvm::StoreTest1 test;
    test.InitializeTest();
 
    auto ptg = aa::PointsToGraph::create();
    const auto allocaD = ptg->addNodeForAlloca(*test.alloca_d, false);
    const auto allocaC = ptg->addNodeForAlloca(*test.alloca_c, false);
 
    // Assert 2
    EXPECT_EQ(ptg->tryGetNodeSize(allocaD), 4);
    EXPECT_EQ(ptg->tryGetNodeSize(allocaC), 8); // Pointers are 8 bytes
  }
 
  {
    // Arrange 3
    jlm::llvm::AllMemoryNodesTest test;
    test.InitializeTest();
 
    auto ptg = aa::PointsToGraph::create();
    const auto allocaNode = ptg->addNodeForAlloca(test.GetAllocaNode(), false);
    const auto mallocNode = ptg->addNodeForMalloc(test.GetMallocNode(), false);
    const auto deltaNode = ptg->addNodeForDelta(test.GetDeltaNode(), true);
    const auto lambdaNode = ptg->addNodeForLambda(test.GetLambdaNode(), true);
    const auto importNode = ptg->addNodeForImport(test.GetImportOutput(), true);
 
    // Assert 3
    EXPECT_EQ(ptg->tryGetNodeSize(allocaNode), 8);
    EXPECT_EQ(ptg->tryGetNodeSize(mallocNode), 4);
    EXPECT_EQ(ptg->tryGetNodeSize(deltaNode), 8);
    EXPECT_EQ(ptg->tryGetNodeSize(importNode), 4);
    // Function nodes have size 0
    EXPECT_EQ(ptg->tryGetNodeSize(lambdaNode), 0);
  }
}
 
TEST(PointsToGraphTests, testIsMemoryNodeConstant)
{
  using namespace jlm::llvm;
 
  {
    // Arrange
    jlm::llvm::AllMemoryNodesTest test;
    test.InitializeTest();
 
    auto ptg = aa::PointsToGraph::create();
    const auto allocaNode = ptg->addNodeForAlloca(test.GetAllocaNode(), false);
    const auto mallocNode = ptg->addNodeForMalloc(test.GetMallocNode(), false);
    const auto deltaNode = ptg->addNodeForDelta(test.GetDeltaNode(), true);
    const auto lambdaNode = ptg->addNodeForLambda(test.GetLambdaNode(), true);
    const auto importNode = ptg->addNodeForImport(test.GetImportOutput(), true);
 
    // Assert
    EXPECT_FALSE(ptg->isNodeConstant(allocaNode));
    EXPECT_FALSE(ptg->isNodeConstant(mallocNode));
    EXPECT_FALSE(ptg->isNodeConstant(deltaNode));
    EXPECT_FALSE(ptg->isNodeConstant(importNode));
    // Functions are always constant
    EXPECT_TRUE(ptg->isNodeConstant(lambdaNode));
  }
 
  {
    // Arrange 2
    jlm::rvsdg::Graph graph;
    const auto intType = jlm::rvsdg::BitType::Create(32);
    const auto pointerType = jlm::llvm::PointerType::Create();
 
    auto & constImport = LlvmGraphImport::createGlobalImport(
        graph,
        intType,
        pointerType,
        "test",
        Linkage::externalLinkage,
        true,
        4);
    auto & nonConstImport = LlvmGraphImport::createGlobalImport(
        graph,
        intType,
        pointerType,
        "test",
        Linkage::externalLinkage,
        false,
        4);
 
    auto & constDelta = *jlm::rvsdg::DeltaNode::Create(
        &graph.GetRootRegion(),
        DeltaOperation::Create(intType, "constGlobal", Linkage::internalLinkage, "data", true, 4));
    const auto & int2 = IntegerConstantOperation::Create(*constDelta.subregion(), 32, 2);
    constDelta.finalize(int2.output(0));
 
    auto & nonConstDelta = *jlm::rvsdg::DeltaNode::Create(
        &graph.GetRootRegion(),
        DeltaOperation::Create(intType, "global", Linkage::internalLinkage, "data", false, 4));
    const auto & int8 = IntegerConstantOperation::Create(*nonConstDelta.subregion(), 32, 8);
    nonConstDelta.finalize(int8.output(0));
 
    auto ptg = aa::PointsToGraph::create();
    const auto constImportMemoryNode = ptg->addNodeForImport(constImport, true);
    const auto nonConstImportMemoryNode = ptg->addNodeForImport(nonConstImport, true);
 
    const auto & constDeltaMemoryNode = ptg->addNodeForDelta(constDelta, false);
    const auto & nonConstDeltaMemoryNode = ptg->addNodeForDelta(nonConstDelta, false);
 
    // Assert
    EXPECT_TRUE(ptg->isNodeConstant(constImportMemoryNode));
    EXPECT_FALSE(ptg->isNodeConstant(nonConstImportMemoryNode));
    EXPECT_TRUE(ptg->isNodeConstant(constDeltaMemoryNode));
    EXPECT_FALSE(ptg->isNodeConstant(nonConstDeltaMemoryNode));
  }
}