From 5c533ae837a2101e620a4e2f06acaa35f16e5fa7 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 10 Nov 2002 06:48:24 +0000
Subject: [PATCH] Implement swapping

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4674 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Analysis/DSNode.h               | 15 +++++++++++++++
 include/llvm/Analysis/DataStructure/DSNode.h | 15 +++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/include/llvm/Analysis/DSNode.h b/include/llvm/Analysis/DSNode.h
index 7726d72f378..64748d85b6f 100644
--- a/include/llvm/Analysis/DSNode.h
+++ b/include/llvm/Analysis/DSNode.h
@@ -271,4 +271,19 @@ inline void DSNodeHandle::mergeWith(const DSNodeHandle &Node) {
     *this = Node;
 }
 
+inline void DSNodeHandle::swap(DSNodeHandle &NH) {
+  std::swap(Offset, NH.Offset);
+  if (N != NH.N) {
+    if (N) {
+      N->removeReferrer(this);
+      N->addReferrer(&NH);
+    }
+    if (NH.N) {
+      N->removeReferrer(&NH);
+      N->addReferrer(this);
+    }
+    std::swap(N, NH.N);
+  }
+}
+
 #endif
diff --git a/include/llvm/Analysis/DataStructure/DSNode.h b/include/llvm/Analysis/DataStructure/DSNode.h
index 7726d72f378..64748d85b6f 100644
--- a/include/llvm/Analysis/DataStructure/DSNode.h
+++ b/include/llvm/Analysis/DataStructure/DSNode.h
@@ -271,4 +271,19 @@ inline void DSNodeHandle::mergeWith(const DSNodeHandle &Node) {
     *this = Node;
 }
 
+inline void DSNodeHandle::swap(DSNodeHandle &NH) {
+  std::swap(Offset, NH.Offset);
+  if (N != NH.N) {
+    if (N) {
+      N->removeReferrer(this);
+      N->addReferrer(&NH);
+    }
+    if (NH.N) {
+      N->removeReferrer(&NH);
+      N->addReferrer(this);
+    }
+    std::swap(N, NH.N);
+  }
+}
+
 #endif