D is being used for autonomous driving research – Audi and Mercedes

Re:D is being used for autonomous driving research – Audi an... by flukus on Tuesday June 25, 2019 @08:28PM (#20280769)

2x is actually pretty significant consider the only difference is the way the comparer is called. Also consider how is easy it is to apply similar boosts in many scenarios with little mental overhead and it's a significant win for c++.

C has _Generic though which can do the same, it seems a bit unfair to be comparing an old method kept for backward compatibility with C89 with whatever version of c++ and the compiler gained this advantage.

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Re:D is being used for autonomous driving research – Audi an... by jstimpfle on Wednesday June 26, 2019 @04:25AM (#20282935)

2x is only for integers, of course. Often you'll have bigger structs to sort.

But anyway. If performance matters (it mostly doesn't; sorting is usually not a bottleneck), you can reap much more than 2x by various tricks

- Improve the data by adding easier to compare fields

- tailor sorting algorithm to the data (what machine types? can we optimize with CPU-specific assembly? Can we do radix sort?, etc)

- avoid the need for sorting altogether. Often, the data can be constructed in a better way such that it falls out sorted.

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