Remove the expensive BitVector::operator~().
authorJakob Stoklund Olesen <stoklund@2pi.dk>
Mon, 14 May 2012 15:46:27 +0000 (15:46 +0000)
committerJakob Stoklund Olesen <stoklund@2pi.dk>
Mon, 14 May 2012 15:46:27 +0000 (15:46 +0000)
Returning a temporary BitVector is very expensive. If you must, create
the temporary explicitly: Use BitVector(A).flip() instead of ~A.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156768 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/BitVector.h
unittests/ADT/BitVectorTest.cpp

index 23aad6e119cdffcd49290e17a701e8bd86df5520..3cbaf1a2f5ef969eb90101b22d11c439e2e1a65c 100644 (file)
@@ -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.");
index 24ce3dd22a2bee7c121a49f7e067c0ef5956c0aa..62aadf6f0e70088882c80001a638e6addbdc8a19 100644 (file)
@@ -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());