[PATCH] D18154: DenseMap: make .resize() do the intuitive thing

[via llvm-commits]

> On Mar 14, 2016, at 1:34 PM, David Blaikie <dblaikie at gmail.com> wrote:
> 
> 
> 
> On Mon, Mar 14, 2016 at 1:31 PM, escha via llvm-commits <llvm-commits at lists.llvm.org <mailto:llvm-commits at lists.llvm.org>> wrote:
> escha updated this revision to Diff 50637.
> escha added a comment.
> 
> Added a test to make sure that resizing is enough to insert N elements without reallocation for a variety of sizes.
> 
> I also looked quickly over the uses and none of the uses seem to be already-compensating for this.
> 
> 
> Repository:
>   rL LLVM
> 
> http://reviews.llvm.org/D18154 <http://reviews.llvm.org/D18154>
> 
> Files:
>   include/llvm/ADT/DenseMap.h
>   unittests/ADT/DenseMapTest.cpp
> 
> Index: unittests/ADT/DenseMapTest.cpp
> ===================================================================
> --- unittests/ADT/DenseMapTest.cpp
> +++ unittests/ADT/DenseMapTest.cpp
> @@ -339,6 +339,19 @@
>    EXPECT_TRUE(cit == cit2);
>  }
> 
> +// Make sure resize actually gives us enough buckets to insert N items
> +// without increasing allocation size.
> +TEST(DenseMapCustomTest, ResizeTest) {
> +  for (unsigned Size = 16; Size < 32; ++Size) {
> +    DenseMap<unsigned, unsigned> Map;
> +    Map.resize(Size);
> +    unsigned MemorySize = Map.getMemorySize();
> +    for (unsigned i = 0; i < Size; ++i)
> +      Map[i] = i;
> +    EXPECT_TRUE(Map.getMemorySize() == MemorySize);
> 
> This is probably sufficient (just checking that the size didn't change) - but in case it's of interest, I was thinking of a unit test with a move-or-copy-counting object in the key or value of the map, then checking no extra moves-or-copies occur.

I have to admit this is probably beyond my C++ knowledge/abilities to do!

— escha
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160314/c4c34ce6/attachment.html>