1 files changed, 203 insertions, 0 deletions
diff --git a/lib/Analysis/DDG.cpp b/lib/Analysis/DDG.cpp
new file mode 100644
index 000000000000..b5c3c761ad98
--- /dev/null
+++ b/lib/Analysis/DDG.cpp
@@ -0,0 +1,203 @@
+//===- DDG.cpp - Data Dependence Graph -------------------------------------==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// The implementation for the data dependence graph.
+//===----------------------------------------------------------------------===//
+#include "llvm/Analysis/DDG.h"
+#include "llvm/Analysis/LoopInfo.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "ddg"
+
+template class llvm::DGEdge<DDGNode, DDGEdge>;
+template class llvm::DGNode<DDGNode, DDGEdge>;
+template class llvm::DirectedGraph<DDGNode, DDGEdge>;
+
+//===--------------------------------------------------------------------===//
+// DDGNode implementation
+//===--------------------------------------------------------------------===//
+DDGNode::~DDGNode() {}
+
+bool DDGNode::collectInstructions(
+    llvm::function_ref<bool(Instruction *)> const &Pred,
+    InstructionListType &IList) const {
+  assert(IList.empty() && "Expected the IList to be empty on entry.");
+  if (isa<SimpleDDGNode>(this)) {
+    for (auto *I : cast<const SimpleDDGNode>(this)->getInstructions())
+      if (Pred(I))
+        IList.push_back(I);
+  } else
+    llvm_unreachable("unimplemented type of node");
+  return !IList.empty();
+}
+
+raw_ostream &llvm::operator<<(raw_ostream &OS, const DDGNode::NodeKind K) {
+  const char *Out;
+  switch (K) {
+  case DDGNode::NodeKind::SingleInstruction:
+    Out = "single-instruction";
+    break;
+  case DDGNode::NodeKind::MultiInstruction:
+    Out = "multi-instruction";
+    break;
+  case DDGNode::NodeKind::Root:
+    Out = "root";
+    break;
+  case DDGNode::NodeKind::Unknown:
+    Out = "??";
+    break;
+  }
+  OS << Out;
+  return OS;
+}
+
+raw_ostream &llvm::operator<<(raw_ostream &OS, const DDGNode &N) {
+  OS << "Node Address:" << &N << ":" << N.getKind() << "\n";
+  if (isa<SimpleDDGNode>(N)) {
+    OS << " Instructions:\n";
+    for (auto *I : cast<const SimpleDDGNode>(N).getInstructions())
+      OS.indent(2) << *I << "\n";
+  } else if (!isa<RootDDGNode>(N))
+    llvm_unreachable("unimplemented type of node");
+
+  OS << (N.getEdges().empty() ? " Edges:none!\n" : " Edges:\n");
+  for (auto &E : N.getEdges())
+    OS.indent(2) << *E;
+  return OS;
+}
+
+//===--------------------------------------------------------------------===//
+// SimpleDDGNode implementation
+//===--------------------------------------------------------------------===//
+
+SimpleDDGNode::SimpleDDGNode(Instruction &I)
+  : DDGNode(NodeKind::SingleInstruction), InstList() {
+  assert(InstList.empty() && "Expected empty list.");
+  InstList.push_back(&I);
+}
+
+SimpleDDGNode::SimpleDDGNode(const SimpleDDGNode &N)
+    : DDGNode(N), InstList(N.InstList) {
+  assert(((getKind() == NodeKind::SingleInstruction && InstList.size() == 1) ||
+          (getKind() == NodeKind::MultiInstruction && InstList.size() > 1)) &&
+         "constructing from invalid simple node.");
+}
+
+SimpleDDGNode::SimpleDDGNode(SimpleDDGNode &&N)
+    : DDGNode(std::move(N)), InstList(std::move(N.InstList)) {
+  assert(((getKind() == NodeKind::SingleInstruction && InstList.size() == 1) ||
+          (getKind() == NodeKind::MultiInstruction && InstList.size() > 1)) &&
+         "constructing from invalid simple node.");
+}
+
+SimpleDDGNode::~SimpleDDGNode() { InstList.clear(); }
+
+//===--------------------------------------------------------------------===//
+// DDGEdge implementation
+//===--------------------------------------------------------------------===//
+
+raw_ostream &llvm::operator<<(raw_ostream &OS, const DDGEdge::EdgeKind K) {
+  const char *Out;
+  switch (K) {
+  case DDGEdge::EdgeKind::RegisterDefUse:
+    Out = "def-use";
+    break;
+  case DDGEdge::EdgeKind::MemoryDependence:
+    Out = "memory";
+    break;
+  case DDGEdge::EdgeKind::Rooted:
+    Out = "rooted";
+    break;
+  case DDGEdge::EdgeKind::Unknown:
+    Out = "??";
+    break;
+  }
+  OS << Out;
+  return OS;
+}
+
+raw_ostream &llvm::operator<<(raw_ostream &OS, const DDGEdge &E) {
+  OS << "[" << E.getKind() << "] to " << &E.getTargetNode() << "\n";
+  return OS;
+}
+
+//===--------------------------------------------------------------------===//
+// DataDependenceGraph implementation
+//===--------------------------------------------------------------------===//
+using BasicBlockListType = SmallVector<BasicBlock *, 8>;
+
+DataDependenceGraph::DataDependenceGraph(Function &F, DependenceInfo &D)
+    : DependenceGraphInfo(F.getName().str(), D) {
+  BasicBlockListType BBList;
+  for (auto &BB : F.getBasicBlockList())
+    BBList.push_back(&BB);
+  DDGBuilder(*this, D, BBList).populate();
+}
+
+DataDependenceGraph::DataDependenceGraph(const Loop &L, DependenceInfo &D)
+    : DependenceGraphInfo(Twine(L.getHeader()->getParent()->getName() + "." +
+                                L.getHeader()->getName())
+                              .str(),
+                          D) {
+  BasicBlockListType BBList;
+  for (BasicBlock *BB : L.blocks())
+    BBList.push_back(BB);
+  DDGBuilder(*this, D, BBList).populate();
+}
+
+DataDependenceGraph::~DataDependenceGraph() {
+  for (auto *N : Nodes) {
+    for (auto *E : *N)
+      delete E;
+    delete N;
+  }
+}
+
+bool DataDependenceGraph::addNode(DDGNode &N) {
+  if (!DDGBase::addNode(N))
+    return false;
+
+  // In general, if the root node is already created and linked, it is not safe
+  // to add new nodes since they may be unreachable by the root.
+  // TODO: Allow adding Pi-block nodes after root is created. Pi-blocks are an
+  // exception because they represent components that are already reachable by
+  // root.
+  assert(!Root && "Root node is already added. No more nodes can be added.");
+  if (isa<RootDDGNode>(N))
+    Root = &N;
+
+  return true;
+}
+
+raw_ostream &llvm::operator<<(raw_ostream &OS, const DataDependenceGraph &G) {
+  for (auto *Node : G)
+    OS << *Node << "\n";
+  return OS;
+}
+
+//===--------------------------------------------------------------------===//
+// DDG Analysis Passes
+//===--------------------------------------------------------------------===//
+
+/// DDG as a loop pass.
+DDGAnalysis::Result DDGAnalysis::run(Loop &L, LoopAnalysisManager &AM,
+                                     LoopStandardAnalysisResults &AR) {
+  Function *F = L.getHeader()->getParent();
+  DependenceInfo DI(F, &AR.AA, &AR.SE, &AR.LI);
+  return std::make_unique<DataDependenceGraph>(L, DI);
+}
+AnalysisKey DDGAnalysis::Key;
+
+PreservedAnalyses DDGAnalysisPrinterPass::run(Loop &L, LoopAnalysisManager &AM,
+                                              LoopStandardAnalysisResults &AR,
+                                              LPMUpdater &U) {
+  OS << "'DDG' for loop '" << L.getHeader()->getName() << "':\n";
+  OS << *AM.getResult<DDGAnalysis>(L, AR);
+  return PreservedAnalyses::all();
+}