* Split up `PartitionWitness` data
This addresses two minor inefficiencies:
- Some preprocessed forest data was being cloned during proving.
- Some of the `ForestNode` data (like node sizes) is only needed in preprocessing, not proving. It was taking up cache space during proving because it was interleaved with data that is used during proving (parents, values).
Now `Forest` contains the disjoint-set forest. `PartitionWitness` is now mainly a Vec of target values; it also holds a reference to the (preprocessed) representative map.
On my laptop, this speeds up witness generation ~12%, resulting in an overall ~0.5% speedup.
* Feedback
* No size data (#278)
* No size data
* feedback
* Some changes to generator_indices_by_watches
- Index generators by the representatives (in disjoint-set forest terminology) of their watched targets, rather than the watched targets themselves. Enqueuing generators based on their watch lists then works correctly, so we no longer need the step where we reenqueue all generators.
- In #195, it was pointed out that this slows down witness generation a bit. I moved the indexing code to preprocessing, so the prover is a bit faster (~7ms for me).
* Outdated comment
* Panic instead of infinite loop if we get stuck
* BTree
* fmt
* Refactor GMiMC code
Adds a sub-trait of `Field` called `GMiMCInterface`, which is similar to `PoseidonInterface`.
This lets us have different fields with different GMiMC constants in a type-safe way.
* Remove `Interface`
* Const generic for width
* Move some Field members to a Field64 subtrait
I.e. move anything specific to 64-bit fields.
Also, relatedly,
- Tweak a bunch of prover code to require `Field64`, since 64-bit stuff is used in a couple places, like the FRI proof-of-work
- Remove `bits()`, which was unused and assumed a 64-bit field
- Rename a couple methods to reflect that they're u64 variants
There are no functional changes.
* Field64 -> PrimeField
* Remove `exp_u32`, `kth_root_u32`
* PrimeField: PrimeField
* Move `to_canonical_biguint` as well
* Add back from_noncanonical_u128
- Made some methods public, if they seemed like they'd be useful crates that depend on plonky2, and seemed like good/stable APIs
- Deleted a few things I didn't think seemed very useful
- Left a few for now that I was on the fence about
Mainly storing pending generators in a Vec rather than a HashMap. Requires an extra check to make sure we don't run one twice after adding it to the Vec twice.
No functional changes here. The biggest change was moving certain files into new directories like `plonk` and `iop` (for things like `Challenger` that could be used in STARKs or other IOPs). I also split a few files, renames, etc, but again nothing functional, so I don't think a careful review is necessary (just a sanity check).
