Whether the function contains non-tail calls to OCaml functions. Calls to C functions don't count.

Whether the function must allocate a stack frame on entry, for one of the following reasons:

• some local variables are stack-allocated
• the function needs to save its return address on the stack, e.g.: -- it contains a non-tail call to an OCaml function -- it calls a C function -- it contains an allocation or a poll point -- it performs an array bound check (on some ports)

Amount of stack space used, in bytes, in addition to the initial stack frame. This counts trap handlers and "outgoing" stack slots used for parameter passing.