Plant ID (not Malabar spinach)

Does anyone know what this semi-vining (gets long and tall and weaves in and out of a wire fence, but has no tendrils) perennial green is?  The person I originally got it from called it Malabar spinach, but on looking at photos of Malabar spinach (Basella alba/rubra), it appears quite different.  The leaves of this plant are thin (not succulent, as B. albas' are) and pointed, not rounded, and as I mentioned above it has no tendrils and does not curve or twist around its supports.  It is hardy in my Zone 7-8 yard, but dies down after a frost, and does equally well in sun to mostly shade with very little water (though it requires more water in the sun, of course).  I'd love to know what it actually is!

Could it be Sweet Potato, which has edible foliage and will come back from a dormant tuber?

Thanks for your response, Tyler.  Hmmm, the leaves do look a lot like sweet potato leaves, don't they?  I don't recall the stem/stalk of sweet potato to be segmented like these are, though, and I've never seen a sweet potato so upright in form - usually they're more trailing, aren't they?  I wonder if it's related to sweet potato, though.  I'll have to dig down and see if it forms tubers (usually I propagate by cuttings, as they root very easily).