5 int model_swapcontext(ucontext_t *oucp, ucontext_t *ucp)
8 * Mac OSX swapcontext() clobbers some registers, so use a hand-rolled
9 * version with {get,set}context(). We can avoid the same problem
10 * (where optimizations can break the following code) because we don't
11 * statically link with the C library
14 /* volatile, so that 'i' doesn't get promoted to a register */