casting function pointer to unsigned long gives wrong result

I have the equivalent of:

  typedef unsigned long codeptr_t;

  void y(void) {};

  codeptr_t x = (codeptr_t) y;

The compiler accepts this with no error or warning, but actually discards the high bytes, effectively doing:

  codeptr_t x = (codeptr_t)((unsigned int) y);

This is in the context of the task scheduler of a RTOS.

Environment is MSP430F5438 on CCS Version: 5.1.1.00031