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by nomemory 1662 days ago
I've assumed they were inline initially, until I profiled and found out one of the swap methods was not. I believe there's also a limit on the amount of bytecode to inline, so no matter how hot a method, if the associated bytecode reaches a certain threshold it won't be. I need to double check though.
1 comments

Indeed, max bytecode count (FreqInlineSize and MaxInlineSize) and inlining depth (MaxInlineLevel). Your GC choice will also slightly modify the inlining decisions, and then obviously GraalVM will be completely different.
Is there a full list of the differences between the graal jit and C2? I was only aware of graal having better partial escape analysis over C2's conservative EA.
It's simply a completely different implementation. Some of the optimiization passes are the same, obviously, but overall it simply performs ... differently.
But inlining will not cause better performance in every case, will it?
Correct! Inlining obviously costs CPU, code cache space, and makes the receiver method bigger so that it's less likely it will be inlined itself. If there ever is a decompilation occuring, the inlining efforts were pretty much wasted.
However it must be pointed out that inlining enables further optimisations.

The tradeoffs are more complicated for a jit, but for an aot compiler it’s one of the most important optimisations in the pipeline.