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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2013-06-07 14:14:38 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2013-06-07 14:14:38 +0000 |
| commit | 597253da97ec4fa5fa4a03c2230ed026b1b6aad6 (patch) | |
| tree | 8856f89933a852b2be083527c227dec30c124c39 /include/llvm/ADT/BitVector.h | |
| parent | 041399aad5a3d93c2dc9d2b70cb9b87d4a987ece (diff) | |
| download | llvm-597253da97ec4fa5fa4a03c2230ed026b1b6aad6.tar.gz llvm-597253da97ec4fa5fa4a03c2230ed026b1b6aad6.tar.bz2 llvm-597253da97ec4fa5fa4a03c2230ed026b1b6aad6.tar.xz | |
Optimize BitVector::all().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183521 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/ADT/BitVector.h')
| -rw-r--r-- | include/llvm/ADT/BitVector.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/include/llvm/ADT/BitVector.h b/include/llvm/ADT/BitVector.h index 3789db4e45..8f512f5c2c 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. |