Missing language features about cascade HOT 4 CLOSED

We'll start with support for signed-ness.

Right now, we're a little bit inconsistent about how we treat signs, so cascade's correctness is all over the place. The big issue is that we're lacking useful invariants in the underlying implementation of Bits. Notably, depending on the operations you perform on a bits, you may inadvertently zero pad the representation of a number, effectively upsetting its sign. Let's start by shoring this up.

from cascade.

This turned into a pretty large edit which involved gutting our dependence on libgmp and rolling our own big int library. All tests are currently passing and we have support for signed integers now with no performance regression (actually a bit of a performance increase). I need to check correctness on the de10 since we don't have automated regression tests there yet. Once that's done, I'll commit back against master.

from cascade.

All tests pass in software and hardware (including new sign tests). Time to make signs official.

from cascade.

Next on the list is support for arrays. I'm going to make this a separate ticket, since I anticipate we'll see more tickets like this soon, and it's nice to keep them from getting too large.

from cascade.