[Alignment][NFC] Adding a max function.

Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68201

llvm-svn: 373196

1 files changed, 23 insertions, 0 deletions

diff --git a/llvm/unittests/Support/AlignmentTest.cpp b/llvm/unittests/Support/AlignmentTest.cpp
index f9cc27b8f42..0b1435912b9 100644
--- a/llvm/unittests/Support/AlignmentTest.cpp
+++ b/llvm/unittests/Support/AlignmentTest.cpp
@@ -227,6 +227,29 @@ TEST(AlignmentTest, AlignComparisons) {
   }
 }
 
+TEST(AlignmentTest, Max) {
+  // We introduce std::max here to test ADL.
+  using std::max;
+
+  // Uses llvm::max.
+  EXPECT_EQ(max(MaybeAlign(), Align(2)), Align(2));
+  EXPECT_EQ(max(Align(2), MaybeAlign()), Align(2));
+
+  EXPECT_EQ(max(MaybeAlign(1), Align(2)), Align(2));
+  EXPECT_EQ(max(Align(2), MaybeAlign(1)), Align(2));
+
+  EXPECT_EQ(max(MaybeAlign(2), Align(2)), Align(2));
+  EXPECT_EQ(max(Align(2), MaybeAlign(2)), Align(2));
+
+  EXPECT_EQ(max(MaybeAlign(4), Align(2)), Align(4));
+  EXPECT_EQ(max(Align(2), MaybeAlign(4)), Align(4));
+
+  // Uses std::max.
+  EXPECT_EQ(max(Align(2), Align(4)), Align(4));
+  EXPECT_EQ(max(MaybeAlign(2), MaybeAlign(4)), MaybeAlign(4));
+  EXPECT_EQ(max(MaybeAlign(), MaybeAlign()), MaybeAlign());
+}
+
 TEST(AlignmentTest, AssumeAligned) {
   EXPECT_EQ(assumeAligned(0), Align(1));
   EXPECT_EQ(assumeAligned(0), Align());