Adel Prokurov (Feb 21 2022 at 09:35): Adel Prokurov (Feb 21 2022 at 09:35):Hello! I want to implement ICs using hot swapping, I found out there is CallConv::Fast, is it the calling convention I should use to call into IC entries?
fitzgen (he/him) (Feb 22 2022 at 18:55):although you could probably make ICs that technically work with cranelift, it doesn't really have built in support for it and I would be surprised if you could get something that worked well out of it
I don't know a ton about the implementation of ICs but I would expect you would ideally want a tail call style ABI for them, for example, and cranelift doesn't have any support for tail calls right now
Chris Fallin (Feb 22 2022 at 19:00):Yep, tail calls and lack of prologue/epilogue are the two key bits; we don't have either right now, but they could (and probably eventually will) be added
Chris Fallin (Feb 22 2022 at 19:01):For now, what one could do is implement an "IC interpreter loop", where ICs are given indices, and every IC site calls this function, and the function body is a loop around a switch(ic_index) { ... }
Chris Fallin (Feb 22 2022 at 19:01):that's not as efficient, but at least has the desired semantics wrt tail calls (no stack growth) while chaining
Last updated: Nov 22 2024 at 16:03 UTC