Optimize BitVector::all().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183521 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer 2013-06-07 14:14:38 +00:00
parent 041399aad5
commit 597253da97
2 changed files with 18 additions and 2 deletions

View File

@ -138,8 +138,16 @@ public:
/// all - Returns true if all bits are set.
bool all() const {
// TODO: Optimize this.
return count() == size();
if (empty())
return true;
for (unsigned i = 0; i < NumBitWords(size()) - 1; ++i)
if (Bits[i] != ~0UL)
return false;
// For the last word check that the lower bits are ones. The unused bits are
// always zero.
return Bits[NumBitWords(size()) - 1] == ~(~0UL << (Size % BITWORD_SIZE));
}
/// none - Returns true if none of the bits are set.

View File

@ -141,6 +141,14 @@ TYPED_TEST(BitVectorTest, TrivialOperation) {
EXPECT_TRUE(Vec.none());
EXPECT_FALSE(Vec.empty());
Vec.flip();
EXPECT_EQ(130U, Vec.count());
EXPECT_EQ(130U, Vec.size());
EXPECT_TRUE(Vec.any());
EXPECT_TRUE(Vec.all());
EXPECT_FALSE(Vec.none());
EXPECT_FALSE(Vec.empty());
Inv = TypeParam().flip();
EXPECT_EQ(0U, Inv.count());
EXPECT_EQ(0U, Inv.size());