On Mon, 20 Jun 2022 at 17:58, François Dumont via Libstdc++ <libstd...@gcc.gnu.org> wrote: > > Hi > > Here is a series of patch to enhance _Hashtable behavior mostly in the > context of range insertion. I also start considering the problem of > memory fragmentation in this container with 2 objectives: > > - It is easier to find out when you're done with the elements of a > bucket if the last node of the bucket N is the before-begin node of > bucket N + 1. > > - It is faster to loop through nodes of a bucket if those node are close > in memory, ultimately we should have addressof(Node + 1) == > addressof(Node) + 1
Have these changes been profiled or benchmarked? Is it measurably faster? By how much? > [1/5] Make more use of user hints as both insertion and allocation hints. > > [2/5] Introduce a new method to check if we are still looping through > the same bucket's nodes > > [3/5] Consider that all initializer_list elements are going to be inserted > > [4/5] Introduce a before-begin cache policy to remember which bucket is > currently pointing on it > > [5/5] Prealloc nodes on _Hashtable copy and introduce a new assignment > method which replicate buckets data structure > > François >
