jit compiles trace:
<trace call> -- parameter (1213,1213) both 64-bit
|
v
ffi_closure_SYSV
|
v
ffi_closure_helper_SYSV (1)
|
v
< enters ctypes>
closure_fcn <callback.c>
|
v
_CallPythonObject <callback.c>
  |
  v
  <calls the python function that returns 1213+1213 = 2426
  as 64bit integer> (2)
  |
  v
  <calls h_set [2]. good, because we instructed it to do this> (3)
  contents of the buffer of (1) before the call: 0xdeadbeefdeadbeef
  contents of the buffer of (1) after the call: 0xdeadbeefdead097a
||
vv
returns every frame back to <trace call> and saves 0xdeadbeefdead097a
in the variable e.g. i42 = call_i(..., 1213, 1213)

(1) provides the stack location (3) writes the result to
(2) leads into ll2types.py internal_callback and returns 2426L