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author | Dan Gohman <gohman@apple.com> | 2010-01-05 18:24:00 +0000 |
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committer | Dan Gohman <gohman@apple.com> | 2010-01-05 18:24:00 +0000 |
commit | c83a2b431f9f0612009a670eae507f7f44bda2f2 (patch) | |
tree | ee483ce067f1afbe9e7ad6f73cbc9c8e1a05ca2a /docs/ProgrammersManual.html | |
parent | ede69f16ad9f4e29e7782e6193ad5cf9016a739c (diff) | |
download | external_llvm-c83a2b431f9f0612009a670eae507f7f44bda2f2.zip external_llvm-c83a2b431f9f0612009a670eae507f7f44bda2f2.tar.gz external_llvm-c83a2b431f9f0612009a670eae507f7f44bda2f2.tar.bz2 |
Add an entry on SmallBitVector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92747 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/ProgrammersManual.html')
-rw-r--r-- | docs/ProgrammersManual.html | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/docs/ProgrammersManual.html b/docs/ProgrammersManual.html index e4e3dc2..7845d99 100644 --- a/docs/ProgrammersManual.html +++ b/docs/ProgrammersManual.html @@ -94,6 +94,7 @@ option</a></li> <li><a href="#ds_bit">BitVector-like containers</a> <ul> <li><a href="#dss_bitvector">A dense bitvector</a></li> + <li><a href="#dss_smallbitvector">A "small" dense bitvector</a></li> <li><a href="#dss_sparsebitvector">A sparse bitvector</a></li> </ul></li> </ul> @@ -1584,7 +1585,7 @@ please don't use it.</p> </div> <div class="doc_text"> -<p> The BitVector container provides a fixed size set of bits for manipulation. +<p> The BitVector container provides a dynamic size set of bits for manipulation. It supports individual bit setting/testing, as well as set operations. The set operations take time O(size of bitvector), but operations are performed one word at a time, instead of one bit at a time. This makes the BitVector very fast for @@ -1595,6 +1596,25 @@ the number of set bits to be high (IE a dense set). <!-- _______________________________________________________________________ --> <div class="doc_subsubsection"> + <a name="dss_smallbitvector">SmallBitVector</a> +</div> + +<div class="doc_text"> +<p> The SmallBitVector container provides the same interface as BitVector, but +it is optimized for the case where only a small number of bits, less than +25 or so, are needed. It also transparently supports larger bit counts, but +slightly less efficiently than a plain BitVector, so SmallBitVector should +only be used when larger counts are rare. +</p> + +<p> +At this time, SmallBitVector does not support set operations (and, or, xor), +and its operator[] does not provide an assignable lvalue. +</p> +</div> + +<!-- _______________________________________________________________________ --> +<div class="doc_subsubsection"> <a name="dss_sparsebitvector">SparseBitVector</a> </div> |