pytorch/torch/distributed/optim/utils.py
Rohan Varma f5a71ec2d6 [Opt Overlap] Implement as_functional_optim and create_functional_optim (#71604)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71604

Implement 2 helper functions:
- as_functional_optim which takes in a torch.optim class type and arguments and
  creates the corresponding functional optimizer.
- create_functional_optim which takes in the functional optimizer class type
  and constructs it. Note that as_functional_optim calls into
  create_functional_optim.

  The first will be used in future PRs as described in
  https://github.com/pytorch/pytorch/issues/67570 to create a functional
  optimizer from a traditional optimizer. The latter is used in
  _OptimizerHookState to create a functional optimizer.

  Both new helper functions are covered by unittests.
ghstack-source-id: 147577170

Test Plan: CI

Reviewed By: cbalioglu

Differential Revision: D33688995

fbshipit-source-id: 8b2daafd1b914efa90877cc4313aa9a428546fc1
(cherry picked from commit 42fdae2991)
2022-01-25 18:32:13 +00:00

42 lines
1.5 KiB
Python

from typing import Type
from torch import optim
from .functional_adagrad import _FunctionalAdagrad
from .functional_adam import _FunctionalAdam
from .functional_adamw import _FunctionalAdamW
from .functional_sgd import _FunctionalSGD
from .functional_adadelta import _FunctionalAdadelta
from .functional_rmsprop import _FunctionalRMSprop
from .functional_rprop import _FunctionalRprop
from .functional_adamax import _FunctionalAdamax
# dict to map a user passed in optimizer_class to a functional
# optimizer class if we have already defined inside the
# distributed.optim package, this is so that we hide the
# functional optimizer to user and still provide the same API.
functional_optim_map = {
optim.Adagrad: _FunctionalAdagrad,
optim.Adam: _FunctionalAdam,
optim.AdamW: _FunctionalAdamW,
optim.SGD: _FunctionalSGD,
optim.Adadelta: _FunctionalAdadelta,
optim.RMSprop: _FunctionalRMSprop,
optim.Rprop: _FunctionalRprop,
optim.Adamax: _FunctionalAdamax,
}
def as_functional_optim(optim_cls: Type, *args, **kwargs):
try:
functional_cls = functional_optim_map[optim_cls]
except KeyError:
raise ValueError(f"Optimizer {optim_cls} does not have a functional counterpart!")
return create_functional_optim(functional_cls, *args, **kwargs)
def create_functional_optim(functional_optim_cls: Type, *args, **kwargs):
return functional_optim_cls(
[],
*args,
**kwargs,
_allow_empty_param_list=True,
)