Changes in directory llvm/docs:
ProgrammersManual.html updated: 1.119 -> 1.120 --- Log message: describe SmallSetVector --- Diffs of the changes: (+14 -5) ProgrammersManual.html | 19 ++++++++++++++----- 1 files changed, 14 insertions(+), 5 deletions(-) Index: llvm/docs/ProgrammersManual.html diff -u llvm/docs/ProgrammersManual.html:1.119 llvm/docs/ProgrammersManual.html:1.120 --- llvm/docs/ProgrammersManual.html:1.119 Sat Feb 3 16:04:27 2007 +++ llvm/docs/ProgrammersManual.html Sat Feb 3 18:00:26 2007 @@ -1016,8 +1016,9 @@ </div> <div class="doc_text"> -<p>LLVM's SetVector<Type> is actually a combination of a set along with -a <a href="#ds_sequential">Sequential Container</a>. The important property +<p>LLVM's SetVector<Type> is an adapter class that combines your choice of +a set-like container along with a <a href="#ds_sequential">Sequential +Container</a>. The important property that this provides is efficient insertion with uniquing (duplicate elements are ignored) with iteration support. It implements this by inserting elements into both a set-like container and the sequential container, using the set-like @@ -1028,7 +1029,7 @@ iteration is guaranteed to match the order of insertion into the SetVector. This property is really important for things like sets of pointers. Because pointer values are non-deterministic (e.g. vary across runs of the program on -different machines), iterating over the pointers in a std::set or other set will +different machines), iterating over the pointers in the set will not be in a well-defined order.</p> <p> @@ -1036,9 +1037,17 @@ set and has the sum of constant factors from the set-like container and the sequential container that it uses. Use it *only* if you need to iterate over the elements in a deterministic order. SetVector is also expensive to delete -elements out of (linear time). +elements out of (linear time), unless you use it's "pop_back" method, which is +faster. </p> +<p>SetVector is an adapter class that defaults to using std::vector and std::set +for the underlying containers, so it is quite expensive. However, +<tt>"llvm/ADT/SetVector.h"</tt> also provides a SmallSetVector class, which +defaults to using a SmallVector and SmallSet of a specified size. If you use +this, and if your sets are dynamically smaller than N, you will save a lot of +heap traffic.</p> + </div> <!-- _______________________________________________________________________ --> @@ -3161,7 +3170,7 @@ <a href="mailto:[EMAIL PROTECTED]">Dinakar Dhurjati</a> and <a href="mailto:[EMAIL PROTECTED]">Chris Lattner</a><br> <a href="http://llvm.org";>The LLVM Compiler Infrastructure</a><br> - Last modified: $Date: 2007/02/03 22:04:27 $ + Last modified: $Date: 2007/02/04 00:00:26 $ </address> </body> _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
