[ADT/MathExtras] Introduce PowerOf2Ceil.

To be used in lld (and probably somewhere else in llvm).

Differential Revision:  https://reviews.llvm.org/D26538

llvm-svn: 286549

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/unittests/Support/MathExtrasTest.cpp b/llvm/unittests/Support/MathExtrasTest.cpp
index d373030881e..c8c49506ce5 100644
--- a/llvm/unittests/Support/MathExtrasTest.cpp
+++ b/llvm/unittests/Support/MathExtrasTest.cpp
@@ -165,6 +165,12 @@ TEST(MathExtras, isPowerOf2_64) {
   EXPECT_FALSE(isPowerOf2_64(0xABCDEF0ABCDEF0LL));
 }
 
+TEST(MathExtras, PowerOf2Ceil) {
+  EXPECT_EQ(0, PowerOf2Ceil(0));
+  EXPECT_EQ(8, PowerOf2Ceil(8));
+  EXPECT_EQ(8, PowerOf2Ceil(7));
+}
+
 TEST(MathExtras, ByteSwap_32) {
   EXPECT_EQ(0x44332211u, ByteSwap_32(0x11223344));
   EXPECT_EQ(0xDDCCBBAAu, ByteSwap_32(0xAABBCCDD));