C++ simulator performance improvements

ProjectQ-Framework / ProjectQ

ProjectQ: An open source software framework for quantum computing

https://projectq.ch

Apache License 2.0

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C++ simulator performance improvements #329

Closed melven closed 5 years ago

melven commented 5 years ago

Multiple changes to increase the performance of the C++ simulator.

Decreases the run-time by a factor of ~2 for our use cases (QAOA) as well as e.g. for the shor algorithm example (e.g. when run in parallel on a workstation with about 20 qubits).

Main changes:

Use native C++ code for common math gates and for the swap gate
Avoid costly memory allocation and copy operations for the StateVector

Takishima commented 5 years ago

Thank you very much for your contribution. I will have a look at it once I am back in the office mid-August.

melven commented 5 years ago

Thanks for the review!

Takishima commented 5 years ago

It seems you have yet to sign the CLA agreement for contributors to ProjectQ. Could you please send an email to info@projectq.ch requesting the CLA and then sign it ?

melven commented 5 years ago

I could finally sign the CLA (after asking my employee).

Let me know when there is still something missing!

Takishima commented 5 years ago

Is all good for me! I'll merge the changes now.