[Bug libstdc++/100133] std::copy extremely slow for random access iterator

2021-04-18 Thread redi at gcc dot gnu.org via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100133 Jonathan Wakely changed: What|Removed |Added Resolution|FIXED |INVALID --- Comment #4 from Jonathan

[Bug libstdc++/100133] std::copy extremely slow for random access iterator

2021-04-18 Thread hewillk at gmail dot com via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100133 康桓瑋 changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution|---

[Bug libstdc++/100133] std::copy extremely slow for random access iterator

2021-04-18 Thread hewillk at gmail dot com via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100133 --- Comment #2 from 康桓瑋 --- After actually executing the same code on my local and remote servers, I did not produce such a result. In both cases, std::copy achieved the expected high-efficiency performance, so I think this should only be Quick

[Bug libstdc++/100133] std::copy extremely slow for random access iterator

2021-04-18 Thread hewillk at gmail dot com via Gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100133 --- Comment #1 from 康桓瑋 --- And the libstdc++‘s std::copy is also 8.9 times slower than the equivalent std::tranfrom: #include #include #include const std::vector v(100, 42); static void copy_from_vector(benchmark::State& state) { for (a