[APInt] Add a concat method, use LLVM_UNLIKELY to help optimizer.

Three unrelated changes:

1) Add a concat method as a convenience to help write bitvector
   use cases in a nicer way.
2) Use LLVM_UNLIKELY as suggested by @xbolva00 in a previous patch.
3) Fix casing of some "slow" methods to follow naming standards.

Differential Revision: https://reviews.llvm.org/D109620

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index 6da9d2d..fe7a231 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -2587,6 +2587,18 @@ TEST(APIntTest, truncOrSelf) {
   EXPECT_EQ(0xFFFFFFFF, val.truncOrSelf(64));
 }
 
+TEST(APIntTest, concatMSB) {
+  APInt Int1(4, 0x1ULL);
+  APInt Int3(4, 0x3ULL);
+
+  EXPECT_EQ(0x31, Int3.concat(Int1));
+  EXPECT_EQ(APInt(12, 0x313), Int3.concat(Int1).concat(Int3));
+  EXPECT_EQ(APInt(16, 0x3313), Int3.concat(Int3).concat(Int1).concat(Int3));
+
+  APInt I64(64, 0x3ULL);
+  EXPECT_EQ(I64, I64.concat(I64).lshr(64).trunc(64));
+}
+
 TEST(APIntTest, multiply) {
   APInt i64(64, 1234);