MathExtras: template'ize alignToPowerOf2 (#97814)

Follow up on 5627794 (MathExtras: avoid unnecessarily widening types) to
change the overflow behavior of alignToPowerOf2 to only overflow if the
result is not representable in the return type. This allows us to
template'ize it, and avoid unnecessarily widening the types of
arguments.

1 files changed, 5 insertions, 2 deletions

diff --git a/llvm/unittests/Support/MathExtrasTest.cpp b/llvm/unittests/Support/MathExtrasTest.cpp
index a1cc609..984185f 100644
--- a/llvm/unittests/Support/MathExtrasTest.cpp
+++ b/llvm/unittests/Support/MathExtrasTest.cpp
@@ -218,8 +218,11 @@ TEST(MathExtras, AlignToPowerOf2) {
   EXPECT_EQ(24u, alignToPowerOf2(17, 8));
   EXPECT_EQ(0u, alignToPowerOf2(~0LL, 8));
   EXPECT_EQ(240u, alignToPowerOf2(240, 16));
-  EXPECT_EQ(static_cast<uint64_t>(std::numeric_limits<uint32_t>::max()) + 1,
-            alignToPowerOf2(std::numeric_limits<uint32_t>::max(), 2));
+
+  // Overflow.
+  EXPECT_EQ(0u, alignToPowerOf2(static_cast<uint8_t>(200),
+                                static_cast<uint8_t>(128)));
+  EXPECT_EQ(0u, alignToPowerOf2(std::numeric_limits<uint32_t>::max(), 2));
 }
 
 TEST(MathExtras, AlignDown) {