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+==================================================
+CPython C extension module produced by recompile()
+==================================================
+
+Global variable::
+
+  _cffi_opcode_t _cffi_types[];
+
+Every _cffi_types entry is initially an odd integer.  At runtime, it
+is fixed to be a `CTypeDescrObject *` when the odd integer is
+interpreted and turned into a real <ctype> object.
+
+The generated C functions are listed in _cffi_globals, a sorted array
+of entries which get turned lazily into real <builtin function
+objects>.  Each entry in this array has an index in the _cffi_types
+array, which describe the function type (OP_FUNCTION opcode, see
+below).  We turn the odd integers describing argument and return types
+into real CTypeDescrObjects at the point where the entry is turned
+into a real builtin function object.
+
+The odd integers are "opcodes" that contain a type info in the lowest
+byte.  The remaining high bytes of the integer is an "arg" that depends
+on the type info:
+
+OP_PRIMITIVE
+    the arg tells which primitive type it is (an index in some list)
+
+OP_POINTER
+    the arg is the index of the item type in the _cffi_types array.
+
+OP_ARRAY
+    the arg is the index of the item type in the _cffi_types array.
+    followed by another opcode that contains (uintptr_t)length_of_array.
+
+OP_OPEN_ARRAY
+    for syntax like "int[]".  same as OP_ARRAY but without the length
+
+OP_STRUCT_UNION
+    the arg is the index of the struct/union in _cffi_structs_unions
+
+OP_ENUM
+    the arg is the index of the enum in _cffi_enums
+
+OP_TYPENAME
+    the arg is the index of the typename in _cffi_typenames
+
+OP_FUNCTION
+    the arg is the index of the result type in _cffi_types.
+    followed by other opcodes for the arguments.
+    terminated by OP_FUNCTION_END.
+
+OP_FUNCTION_END
+    the arg's lowest bit is set if there is a "..." argument.
+
+OP_NOOP
+    simple indirection: the arg is the index to look further in
+
+There are other opcodes, used not inside _cffi_types but in other
+individual ``type_op`` fields.  Most importantly, these are used
+on _cffi_globals entries:
+
+OP_CPYTHON_BLTN_*
+    declare a function
+
+OP_CONSTANT
+    declare a non-integral constant
+
+OP_CONSTANT_INT
+    declare an int constant
+
+OP_GLOBAL_VAR
+    declare a global var