From 597253da97ec4fa5fa4a03c2230ed026b1b6aad6 Mon Sep 17 00:00:00 2001 From: Benjamin Kramer Date: Fri, 7 Jun 2013 14:14:38 +0000 Subject: [PATCH] Optimize BitVector::all(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183521 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/ADT/BitVector.h | 12 ++++++++++-- unittests/ADT/BitVectorTest.cpp | 8 ++++++++ 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/include/llvm/ADT/BitVector.h b/include/llvm/ADT/BitVector.h index 3789db4e45d..8f512f5c2ca 100644 --- a/include/llvm/ADT/BitVector.h +++ b/include/llvm/ADT/BitVector.h @@ -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. diff --git a/unittests/ADT/BitVectorTest.cpp b/unittests/ADT/BitVectorTest.cpp index dc298a83d57..f97be22fd27 100644 --- a/unittests/ADT/BitVectorTest.cpp +++ b/unittests/ADT/BitVectorTest.cpp @@ -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()); -- 2.34.1