[LLVMdev] Stack swapping

[Wesley W. Terpstra]

Thanks to help in a previous thread, I now have a working LLVM codegen
for the MLton compiler. Currently the stack is managed explicitly on
the heap. This way the LLVM codegen re-uses the runtime layout of the
other codegens, simplifying the initial porting effort.

In the next phase I plan to switch to using LLVM to manage the stack,
but there is a sticking point: MLton switches stacks. It does this on
calls to C (which use the primordial C stack) and also between
application-level threads. ML stacks automatically expand when a limit
check triggers garbage collection. I understand that getting this to
work will require some non-portable glue on my part.

I have a number of ideas on how to get this to work, but also assume
that MLton isn't the first project which swaps stacks. What's the
established best practice for managing multiple stacks under LLVM?