Convert PointerUnion to a variadic template.

Summary:
Rather than duplicating code between PointerUnion, PointerUnion3, and
PointerUnion4 (and missing things from the latter cases, such as some of the
DenseMap support and operator==), convert PointerUnion to a variadic template
that can be used as a union of any number of pointers.

(This doesn't support PointerUnion<> right now. Adding a special case for that
would be possible, and perhaps even useful in some situations, but it doesn't
seem worthwhile until we have a concrete use case.)

Reviewers: dblaikie

Subscribers: dexonsmith, kristina, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62027

llvm-svn: 360962

1 files changed, 37 insertions, 0 deletions

diff --git a/llvm/unittests/ADT/PointerUnionTest.cpp b/llvm/unittests/ADT/PointerUnionTest.cpp
index 657767a240e..cf961d711d4 100644
--- a/llvm/unittests/ADT/PointerUnionTest.cpp
+++ b/llvm/unittests/ADT/PointerUnionTest.cpp
@@ -68,4 +68,41 @@ TEST_F(PointerUnionTest, Get) {
   EXPECT_EQ(n.get<int *>(), (int *)nullptr);
 }
 
+template<int I> struct alignas(8) Aligned {};
+
+typedef PointerUnion<Aligned<0> *, Aligned<1> *, Aligned<2> *, Aligned<3> *,
+                     Aligned<4> *, Aligned<5> *, Aligned<6> *, Aligned<7> *>
+    PU8;
+
+TEST_F(PointerUnionTest, ManyElements) {
+  Aligned<0> a0;
+  Aligned<7> a7;
+
+  PU8 a = &a0;
+  EXPECT_TRUE(a.is<Aligned<0>*>());
+  EXPECT_FALSE(a.is<Aligned<1>*>());
+  EXPECT_FALSE(a.is<Aligned<2>*>());
+  EXPECT_FALSE(a.is<Aligned<3>*>());
+  EXPECT_FALSE(a.is<Aligned<4>*>());
+  EXPECT_FALSE(a.is<Aligned<5>*>());
+  EXPECT_FALSE(a.is<Aligned<6>*>());
+  EXPECT_FALSE(a.is<Aligned<7>*>());
+  EXPECT_EQ(a.dyn_cast<Aligned<0>*>() == &a0);
+  EXPECT_EQ(*a.getAddrOfPtr1() == &a0);
+
+  a = &a7;
+  EXPECT_FALSE(a.is<Aligned<0>*>());
+  EXPECT_FALSE(a.is<Aligned<1>*>());
+  EXPECT_FALSE(a.is<Aligned<2>*>());
+  EXPECT_FALSE(a.is<Aligned<3>*>());
+  EXPECT_FALSE(a.is<Aligned<4>*>());
+  EXPECT_FALSE(a.is<Aligned<5>*>());
+  EXPECT_FALSE(a.is<Aligned<6>*>());
+  EXPECT_TRUE(a.is<Aligned<7>*>());
+  EXPECT_EQ(a.dyn_cast<Aligned<7>*>() == &a7);
+
+  EXPECT_TRUE(a == PU8(&a7));
+  EXPECT_TRUE(a != PU8(&a0));
+}
+
 } // end anonymous namespace