1 files changed, 51 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/Interval.cpp b/llvm/lib/Analysis/Interval.cpp
new file mode 100644
index 000000000000..07d6e27c13be
--- /dev/null
+++ b/llvm/lib/Analysis/Interval.cpp
@@ -0,0 +1,51 @@
+//===- Interval.cpp - Interval class code ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the definition of the Interval class, which represents a
+// partition of a control flow graph of some kind.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/Interval.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Interval Implementation
+//===----------------------------------------------------------------------===//
+
+// isLoop - Find out if there is a back edge in this interval...
+bool Interval::isLoop() const {
+  // There is a loop in this interval iff one of the predecessors of the header
+  // node lives in the interval.
+  for (::pred_iterator I = ::pred_begin(HeaderNode), E = ::pred_end(HeaderNode);
+       I != E; ++I)
+    if (contains(*I))
+      return true;
+  return false;
+}
+
+void Interval::print(raw_ostream &OS) const {
+  OS << "-------------------------------------------------------------\n"
+       << "Interval Contents:\n";
+
+  // Print out all of the basic blocks in the interval...
+  for (const BasicBlock *Node : Nodes)
+    OS << *Node << "\n";
+
+  OS << "Interval Predecessors:\n";
+  for (const BasicBlock *Predecessor : Predecessors)
+    OS << *Predecessor << "\n";
+
+  OS << "Interval Successors:\n";
+  for (const BasicBlock *Successor : Successors)
+    OS << *Successor << "\n";
+}