tree 36f9d19ad7da5f784262b9d9fe23ea8d45efb476
parent 46b8a51b49ec0930425a4c55c68e24f47f47a481
author Vedant Kumar <vsk@apple.com> 1520543726 +0000
committer Vedant Kumar <vsk@apple.com> 1520543726 +0000

Low-hanging fruit optimization in string::__move_assign().

shrink_to_fit() ends up doing a lot work to get information that we
already know since we just called clear(). This change seems concise
enough to be worth the couple extra lines and my benchmarks show that it
is indeed a pretty decent win. It looks like the same thing is going on
twice in __copy_assign_alloc(), but I didn't want to go overboard since
this is my first contribution to llvm/libc++.

Patch by Timothy VanSlyke!

Differential Revision: https://reviews.llvm.org/D41976

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@327064 91177308-0d34-0410-b5e6-96231b3b80d8