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Comment by rjsw | Hacker News Reader

Other people have pointed out that Itanium is the most recent example of a project that expected to be able to write a really smart compiler for an in-order CPU and failed.

If you can write better LLVM plugins then I'm sure Intel and HP will be happy to throw lots of money in your direction.

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The field is littered with the tombstones of people that have tried to make compilers for insert any foreign architecture. Obviously in-order CPUs are a challenge on top of that. I do think there is a real 'go-to-market' problem. If you think about it this is kind of solved by Nvidia (with CUDA). GPUs are in-order computational arrays with custom compiler.

GPUs are vector processors under another name, that hide the latency of memory differently. They don't need to use the sort of compiler tricks you would with CPU code.

Yeah, but GPUs target only a small subset of the workloads and they are very hard to program even then. I prefer processors like the Rex Neo or Adapteva Epiphany in that respect actually.

have you tried programming rex neo?

Nope, I know you have experience with it though, so perhaps you can help there ;)

I've toyed around with the older Epiphanies though, and they were definitely easier than GPUs in many respects.

Also, as I understand it, GPUs are now out of order as well, aren’t they?

No, they are not.

OoO is much more expensive to implement than simply scheduling a different warp to hide latency.

Absolutely not.

Maybe you're confusing the GPU's threading techniques for OoO?

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