Remove the expensive BitVector::operator~().

Returning a temporary BitVector is very expensive. If you must, create
the temporary explicitly: Use BitVector(A).flip() instead of ~A.

llvm-svn: 156768

2 files changed, 4 insertions, 8 deletions

diff --git a/llvm/include/llvm/ADT/BitVector.h b/llvm/include/llvm/ADT/BitVector.h
index 23aad6e119c..3cbaf1a2f5e 100644
--- a/llvm/include/llvm/ADT/BitVector.h
+++ b/llvm/include/llvm/ADT/BitVector.h
@@ -251,11 +251,6 @@ public:
     return *this;
   }
 
-  // No argument flip.
-  BitVector operator~() const {
-    return BitVector(*this).flip();
-  }
-
   // Indexing.
   reference operator[](unsigned Idx) {
     assert (Idx < Size && "Out-of-bounds Bit access.");
diff --git a/llvm/unittests/ADT/BitVectorTest.cpp b/llvm/unittests/ADT/BitVectorTest.cpp
index 24ce3dd22a2..62aadf6f0e7 100644
--- a/llvm/unittests/ADT/BitVectorTest.cpp
+++ b/llvm/unittests/ADT/BitVectorTest.cpp
@@ -42,7 +42,8 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_FALSE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
-  BitVector Inv = ~Vec;
+  BitVector Inv = Vec;
+  Inv.flip();
   EXPECT_EQ(6U, Inv.count());
   EXPECT_EQ(11U, Inv.size());
   EXPECT_TRUE(Inv.any());
@@ -52,7 +53,7 @@ TEST(BitVectorTest, TrivialOperation) {
 
   EXPECT_FALSE(Inv == Vec);
   EXPECT_TRUE(Inv != Vec);
-  Vec = ~Vec;
+  Vec.flip();
   EXPECT_TRUE(Inv == Vec);
   EXPECT_FALSE(Inv != Vec);
 
@@ -131,7 +132,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_TRUE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
-  Inv = ~BitVector();
+  Inv = BitVector().flip();
   EXPECT_EQ(0U, Inv.count());
   EXPECT_EQ(0U, Inv.size());
   EXPECT_FALSE(Inv.any());