SmallPtrSet: Provide a more efficient implementation of swap than the default triple-copy std::swap.

This currently assumes that both sets have the same SmallSize to keep the implementation simple,
a limitation that can be lifted if someone cares.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152143 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 72 insertions, 0 deletions

diff --git a/unittests/ADT/SmallPtrSetTest.cpp b/unittests/ADT/SmallPtrSetTest.cpp
new file mode 100644
index 0000000000..9114875e00
--- /dev/null
+++ b/unittests/ADT/SmallPtrSetTest.cpp
@@ -0,0 +1,72 @@
+//===- llvm/unittest/ADT/SmallPtrSetTest.cpp ------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// SmallPtrSet unit tests.
+//
+//===----------------------------------------------------------------------===//
+
+#include "gtest/gtest.h"
+#include "llvm/ADT/SmallPtrSet.h"
+
+using namespace llvm;
+
+// SmallPtrSet swapping test.
+TEST(SmallPtrSetTest, SwapTest) {
+  int buf[10];
+
+  SmallPtrSet<int *, 2> a;
+  SmallPtrSet<int *, 2> b;
+
+  a.insert(&buf[0]);
+  a.insert(&buf[1]);
+  b.insert(&buf[2]);
+
+  std::swap(a, b);
+
+  EXPECT_EQ(1U, a.size());
+  EXPECT_EQ(2U, b.size());
+  EXPECT_TRUE(a.count(&buf[2]));
+  EXPECT_TRUE(b.count(&buf[0]));
+  EXPECT_TRUE(b.count(&buf[1]));
+
+  b.insert(&buf[3]);
+  std::swap(a, b);
+
+  EXPECT_EQ(3U, a.size());
+  EXPECT_EQ(1U, b.size());
+  EXPECT_TRUE(a.count(&buf[0]));
+  EXPECT_TRUE(a.count(&buf[1]));
+  EXPECT_TRUE(a.count(&buf[3]));
+  EXPECT_TRUE(b.count(&buf[2]));
+
+  std::swap(a, b);
+
+  EXPECT_EQ(1U, a.size());
+  EXPECT_EQ(3U, b.size());
+  EXPECT_TRUE(a.count(&buf[2]));
+  EXPECT_TRUE(b.count(&buf[0]));
+  EXPECT_TRUE(b.count(&buf[1]));
+  EXPECT_TRUE(b.count(&buf[3]));
+
+  a.insert(&buf[4]);
+  a.insert(&buf[5]);
+  a.insert(&buf[6]);
+
+  std::swap(b, a);
+
+  EXPECT_EQ(3U, a.size());
+  EXPECT_EQ(4U, b.size());
+  EXPECT_TRUE(b.count(&buf[2]));
+  EXPECT_TRUE(b.count(&buf[4]));
+  EXPECT_TRUE(b.count(&buf[5]));
+  EXPECT_TRUE(b.count(&buf[6]));
+  EXPECT_TRUE(a.count(&buf[0]));
+  EXPECT_TRUE(a.count(&buf[1]));
+  EXPECT_TRUE(a.count(&buf[3]));
+}