Dear all, while studying camls native code generation and garbage collection strategy, I came upon Connor Benner's bachelor thesis from 2012, where he implemented a llvm backend for ocamlopt. One intriguing remark mentioned OCamls exception mechanism as basically consisting a pointer to the stack frame of the last exception handler in a special register (r14, when I recall correctly). Throwing an exception that becomes a mov/pop/ret operation. This however, seems to interfere with garbage collection: From the C-API, it seems that all local roots are stored in the frametable via some special macros (e.g. CAMLParam, CAMLlocal). When control just returns from a stack frame, how are the entries removed from the frametable? I would be glad, if someone could answer this or point me to the relevant documentation (if any exists). thanks, Christoph