[llvm] [SandboxVec][DAG] Boilerplate (PR #108862)

[via llvm-commits]

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+//===- DependencyGraph.cpp ------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Vectorize/SandboxVectorizer/DependencyGraph.h"
+
+using namespace llvm::sandboxir;
+
+#ifndef NDEBUG
+void DGNode::print(raw_ostream &OS, bool PrintDeps) const {
+  I->dumpOS(OS);
+  if (PrintDeps) {
+    OS << "\n";
+    // Print memory preds.
+    static constexpr const unsigned Indent = 4;
+    for (auto *Pred : MemPreds) {
+      OS.indent(Indent) << "<-";
+      Pred->print(OS, false);
+      OS << "\n";
+    }
+  }
+}
+void DGNode::dump() const {
+  print(dbgs());
+  dbgs() << "\n";
+}
+#endif // NDEBUG
+
+void DependencyGraph::extend(BasicBlock *BB) {
+  if (BB->empty())
+    return;
+  // TODO: For now create a chain of dependencies.
+  DGNode *LastN = getOrCreateNode(&*BB->begin());
+  for (auto &I : drop_begin(*BB)) {
+    auto *N = getOrCreateNode(&I);
+    N->addMemPred(LastN);
+    LastN = N;
+  }
+}
+
+#ifndef NDEBUG
+void DependencyGraph::print(raw_ostream &OS) const {
+  // InstrToNodeMap is unordered so we need to create an ordered vector.
+  SmallVector<DGNode *> Nodes;
+  Nodes.reserve(InstrToNodeMap.size());
+  for (const auto &Pair : InstrToNodeMap)
+    Nodes.push_back(Pair.second.get());
+  // Sort them based on which one comes first in the BB.
+  stable_sort(Nodes, [](DGNode *N1, DGNode *N2) {
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vporpo wrote:

true

https://github.com/llvm/llvm-project/pull/108862