131 lines
3.9 KiB
Python
131 lines
3.9 KiB
Python
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# Copyright 2018 The JAX Authors.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# https://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from __future__ import annotations
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import types
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from typing import Any, Callable, Dict, TypeVar, Union, cast
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from jax._src import core
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from jax._src import traceback_util
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from jax._src.core import (lattice_join, Primitive, valid_jaxtype,
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raise_to_shaped, get_aval)
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from jax._src.tree_util import register_pytree_node
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from jax._src.typing import Array, ArrayLike
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from jax._src.util import safe_map
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traceback_util.register_exclusion(__file__)
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T = TypeVar('T')
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map = safe_map
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jaxval_adders: Dict[type, Callable[[ArrayLike, ArrayLike], Array]] = {}
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def add_jaxvals(x: ArrayLike, y: ArrayLike) -> Array:
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return add_jaxvals_p.bind(x, y)
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add_jaxvals_p: Primitive = Primitive('add_any')
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add_any_p = add_jaxvals_p
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@add_jaxvals_p.def_impl
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def add_impl(xs, ys):
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return jaxval_adders[type(xs)](xs, ys)
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@add_jaxvals_p.def_abstract_eval
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def add_abstract(xs, ys):
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return lattice_join(xs, ys)
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jaxval_zeros_likers: Dict[type, Callable[[Any], Array]] = {}
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def instantiate(z: Union[Zero, Array]) -> Array:
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if type(z) is Zero:
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return zeros_like_aval(z.aval)
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return cast(Array, z)
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def zeros_like_aval(aval: core.AbstractValue) -> Array:
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return aval_zeros_likers[type(aval)](aval)
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aval_zeros_likers: Dict[type, Callable[[Any], Array]] = {}
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def zeros_like_jaxval(val: ArrayLike) -> Array:
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return zeros_like_p.bind(val)
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zeros_like_p: Primitive = Primitive('zeros_like')
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@zeros_like_p.def_impl
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def zeros_like_impl(example):
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return jaxval_zeros_likers[type(example)](example)
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zeros_like_p.def_abstract_eval(lambda x: x)
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class Zero:
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__slots__ = ['aval']
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def __init__(self, aval: core.AbstractValue):
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self.aval = aval
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def __repr__(self) -> str:
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return f'Zero({self.aval})'
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@staticmethod
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def from_value(val: Any) -> Zero:
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return Zero(raise_to_shaped(get_aval(val)))
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register_pytree_node(Zero, lambda z: ((), z.aval), lambda aval, _: Zero(aval))
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def _stop_gradient_impl(x: T) -> T:
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if not valid_jaxtype(x):
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raise TypeError("stop_gradient only works on valid JAX arrays, but "
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f"input argument is: {x}")
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return x
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stop_gradient_p : Primitive = Primitive('stop_gradient')
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stop_gradient_p.def_impl(_stop_gradient_impl)
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stop_gradient_p.def_abstract_eval(lambda x: x)
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class SymbolicZero:
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def __init__(self, aval: core.AbstractValue) -> None:
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self.aval = aval
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def __repr__(self) -> str:
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return self.__class__.__name__
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# TODO(mattjj,frostig): this forwards attr lookup to self.aval delegate;
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# should dedup with core.Tracer.__getattr__ which does the same thing
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def __getattr__(self, name):
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# if the aval property raises an AttributeError, gets caught here
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try:
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attr = getattr(self.aval, name)
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except KeyError as err:
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raise AttributeError(
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f"{self.__class__.__name__} has no attribute {name}"
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) from err
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else:
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t = type(attr)
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if t is core.aval_property:
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return attr.fget(self)
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elif t is core.aval_method:
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return types.MethodType(attr.fun, self)
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else:
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return attr
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JaxTypeOrTracer = Any
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def replace_internal_symbolic_zeros(
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x: Union[JaxTypeOrTracer, Zero]) -> Union[JaxTypeOrTracer, SymbolicZero]:
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return SymbolicZero(x.aval) if type(x) is Zero else x
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def replace_rule_output_symbolic_zeros(
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x: Union[JaxTypeOrTracer, SymbolicZero]) -> Union[JaxTypeOrTracer, Zero]:
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return Zero(x.aval) if type(x) is SymbolicZero else x
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