Aihwkit

Added

* The `rpu_config` is now pretty-printed in a readable manner (excluding the
default settings and other readability tweak). (\60)
* Added a new `ReferenceUnitCell` which has two devices, where one is fixed and
the other updated and the effective weight is computed a difference between
the two. (\61)
* `VectorUnitCell` accepts now arbitrary weighting schemes that can be
user-defined by using a new `gamma_vec` property that specifies how to combine
the unit cell devices to form the effective weight. (\61)

Changed

* The unit cell items in `aihwkit.simulator.configs` have been renamed, removing
their `Device` suffix, for having a more consistent naming scheme. (\57)
* The `Exceptions` raised by the library have been revised, making use in some
cases of the ones introduced in a new `aihwkit.exceptions` module. (\49)
* Some `VectorUnitCell` properties have been renamed and extended with an update
policy specifying how to select the hidden devices. (\61)
* The `pybind11` version required has been bumped to 2.6.0, which can be
installed from `pip` and makes system-wide installation no longer required.
Please update your `pybind11` accordingly for compiling the library. (\44)

Removed

* The `BackwardIOParameters` specialization has been removed, as bound
management is now automatically ignored for the backward pass. Please use the
more general `IOParameters` instead. (\45)

Fixed

* Serialization of `Modules` that contain children analog layers is now
possible, both when using containers such as `Sequential` and when using
analog layers as custom Module attributes. (\74, \80)
* The build system has been improved, with experimental Windows support and
supporting using CUDA 11 correctly. (\58, \67, \68)

Added

* Added more types of resistive devices: `IdealResistiveDevice`, `LinearStep`,
`SoftBounds`, `ExpStep`, `VectorUnitCell`, `TransferCompoundDevice`,
`DifferenceUnitCell`. (\14)
* Added a new `InferenceTile` that supports basic hardware-aware training
and inference using a statistical noise model that was fitted by real PCM
devices. (\25)
* Added a new `AnalogSequential` layer that can be used in place of `Sequential`
for easier operation on children analog layers. (\34)

Changed

* Specifying the tile configuration (resistive device and the rest of the
properties) is now based on a new `RPUConfig` family of classes, that is
passed as a `rpu_config` argument instead of `resistive_device` to `Tiles`
and `Layers`. Please check the `aihwkit.simulator.config` module for more
details. (\23)
* The different analog tiles are now organized into a `aihwkit.simulator.tiles`
package. The internal `IndexedTiles` have been removed, and the rest of
previous top-level imports have been kept. (\29)

Fixed

* Improved package compatibility when using non-UTF8 encodings (version file,
package description). (\13)
* The build system can now detect and use `openblas` directly when using the
conda-installable version. (\22)
* When using analog layers as children of another module, the tiles are now
correctly moved to CUDA if using `AnalogSequential` (or by the optimizer if
using regular torch container modules). (\34)

Added

* Initial public release.
* Added `rpucuda` C++ simulator, exposed through a `pybind` interface.
* Added a PyTorch `AnalogLinear` neural network model.
* Added a PyTorch `AnalogConv2d` neural network model.