Is gcc std::unordered_map implementation slow? If so - why?

Question

We are developing a highly performance critical software in C++. There we need a concurrent hash map and implemented one. So we wrote a benchmark to figure out, how much slo

Answer 1

I have run your code using a 64 bit / AMD / 4 cores (2.1GHz) computer and it gave me the following results:

MinGW-W64 4.9.2:

Using std::unordered_map:

inserts: 9280 
get: 3302

Using std::map:

inserts: 23946
get: 24824

VC 2015 with all the optimization flags I know:

Using std::unordered_map:

inserts: 7289
get: 1908

Using std::map:

inserts: 19222 
get: 19711

I have not tested the code using GCC but I think it may be comparable to the performance of VC, so if that is true, then GCC 4.9 std::unordered_map it's still broken.

[EDIT]

So yes, as someone said in the comments, there is no reason to think that the performance of GCC 4.9.x would be comparable to VC performance. When I have the change I will be testing the code on GCC.

My answer is just to establish some kind of knowledge base to other answers.