Hacker News Reader

Comment by yawgmoth | Hacker News Reader

I would love to see this for C#. Avoiding heap allocations was something I had to tackle as part of a simulation software. C# has a handful of GC generations, and GC gen1 is very fast, but it's still faster to pool things ahead of time.

View on HN

This isn't related to heap allocations. It's about removing the cost of a stack variable being moved into another stack variable.

I became interested in stack performance specifically because I had to avoid heap allocations.

I mean, it's tangentially related, sure. It's also related to ML because computers run ML algorithms and computers run programs with stacks.

While I want to understand your point and welcome enlightenment, so far this conversation has just been kinda weirdly hostile.

Using structs, stack allocations (safe since C# 7.x) and native heap go a long way.

Many of the post C# 7 features have been used to improve .NET performance in techpower benchmarks, and rewrite runtime code from C++ into C#.

You can also use generic functions that take struct arguments instead of delegates to get something like STL. I wish there was some syntactic sugar in the language for that, too - basically, struct lambdas.

There is a bit of that with static lambdas, function pointers (unsafe), but still isn't quite what you want.

Well, until relatively recently, they wouldn't be able to desugar what I really want into underlying bits. But now that we have verifiable ref structs with ref fields in them in C# 11, it's a straightforward transformation. Might be worth a proposal, actually...

You can access C#'s GC metrics through `System.GC.GetTotalAllocatedBytes` and similar APIs. Maybe you can make a benchmark and tracker for it yourself!

Reply on news.ycombinator.com