Move IsSameValue from clang's ASTImporter to be methods on the

APInt/APSInt classes.

Part of rdar://11875995

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160223 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 0 deletions

diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index 75c1d576a6..cacfb5d4c4 100644
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -511,6 +511,18 @@ public:
     return getAllOnesValue(numBits).lshr(numBits - loBitsSet);
   }
 
+  /// \brief Determine if two APInts have the same value, after zero-extending
+  /// one of them (if needed!) to ensure that the bit-widths match.
+  static bool isSameValue(const APInt &I1, const APInt &I2) {
+    if (I1.getBitWidth() == I2.getBitWidth())
+      return I1 == I2;
+
+    if (I1.getBitWidth() > I2.getBitWidth())
+      return I1 == I2.zext(I1.getBitWidth());
+
+    return I1.zext(I2.getBitWidth()) == I2;
+  }
+  
   /// \brief Overload to compute a hash_code for an APInt value.
   friend hash_code hash_value(const APInt &Arg);