Give APInt move semantics.

The interaction between defaulted operators and move elision isn't
totally obvious, add a unit test so it doesn't break unintentionally.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202662 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 10 deletions

diff --git a/include/llvm/ADT/APSInt.h b/include/llvm/ADT/APSInt.h
index ad035a7c30..053defff52 100644
--- a/include/llvm/ADT/APSInt.h
+++ b/include/llvm/ADT/APSInt.h
@@ -30,18 +30,12 @@ public:
   explicit APSInt(uint32_t BitWidth, bool isUnsigned = true)
    : APInt(BitWidth, 0), IsUnsigned(isUnsigned) {}
 
-  explicit APSInt(const APInt &I, bool isUnsigned = true)
-   : APInt(I), IsUnsigned(isUnsigned) {}
+  explicit APSInt(APInt I, bool isUnsigned = true)
+   : APInt(std::move(I)), IsUnsigned(isUnsigned) {}
 
-  APSInt &operator=(const APSInt &RHS) {
-    APInt::operator=(RHS);
-    IsUnsigned = RHS.IsUnsigned;
-    return *this;
-  }
-
-  APSInt &operator=(const APInt &RHS) {
+  APSInt &operator=(APInt RHS) {
     // Retain our current sign.
-    APInt::operator=(RHS);
+    APInt::operator=(std::move(RHS));
     return *this;
   }