This article reminds me of performance advice I was starting to see in the 2000s decade. Basically it was to not introduce a bunch of pointer heavy data structures to get lower algorithmic complexity. Stuff it all into a vector. You will use some algorithms that the computer science textbook will say it's slower, but if it fits all in cache it doesn't matter. The cache misses following pointers all over town hurts you more.
I too am in the "premature optimization bad" camp.
Beyond the low-hanging fruit like ensuring you aren't creating O(n^2) complexity by accident, I think C++ is fast enough/has mature-enough compilers that by the time you're worrying about cache hits materially affecting performance, you're probably also sufficiently staffed and capitalized to pay people to A/B test that performance.
There are multiple areas of work, where C++ can be considered a glue language. The high-performance work is then done in explicit SIMD (intrinsics, ISPC, etc.) and/or GPU-targeting languages such as CUDA or Vulkan.
In these areas of work, high performance is part of the design and not something that can be easily added as after-thought.
Also, relying on optimization features such as compiler auto-vectorization is way too finicky - your hot-loop performance may completely break without anyone noticing by someone changing a trivial-looking part of a loop.
asveikau · · focus · HN ↗
stackghost · · focus · HN ↗
Beyond the low-hanging fruit like ensuring you aren't creating O(n^2) complexity by accident, I think C++ is fast enough/has mature-enough compilers that by the time you're worrying about cache hits materially affecting performance, you're probably also sufficiently staffed and capitalized to pay people to A/B test that performance.
nnevatie · · focus · HN ↗
Yeah, it's really not.
There are multiple areas of work, where C++ can be considered a glue language. The high-performance work is then done in explicit SIMD (intrinsics, ISPC, etc.) and/or GPU-targeting languages such as CUDA or Vulkan.
In these areas of work, high performance is part of the design and not something that can be easily added as after-thought.
Also, relying on optimization features such as compiler auto-vectorization is way too finicky - your hot-loop performance may completely break without anyone noticing by someone changing a trivial-looking part of a loop.