Here's my very funny implementation of delimited continuation in plain C with zero ASM usage (with help from a specific compiler built-in)

https://gist.github.com/Trung0246/8f801058212d3bbbef82690a31...

Demo (old version with outdated compile flag but still works): https://godbolt.org/z/n9ch4TM3s

It works for gcc/clang/msvc with -O0, -O1, -O2, and even -O3