2025-08-11 12:24:21 +08:00

1182 lines
50 KiB
Python

# Copyright 2022 The JAX Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Module for discharging state primitives."""
from __future__ import annotations
from collections.abc import Callable, Sequence
import dataclasses
from functools import partial
import math
import operator
from typing import Any, Protocol, TypeVar
from jax._src import ad_util
from jax._src import api_util
from jax._src import core
from jax._src import linear_util as lu
from jax._src import pjit
from jax._src import sharding_impls
from jax._src import source_info_util
from jax._src import tree_util
from jax._src.interpreters import ad
from jax._src.interpreters import mlir
from jax._src.interpreters import partial_eval as pe
from jax._src.lax import lax
from jax._src.lax import slicing as lax_slicing
from jax._src.state import indexing
from jax._src.state.primitives import addupdate_p, get_p, swap_p
from jax._src.state.types import (
AbstractRef,
RefBitcaster,
RefEffect,
RefReshaper,
get_ref_aval_from_value,
uninitialized,
)
from jax._src.state.utils import bitcast, hoist_consts_to_refs
from jax._src.typing import Array
from jax._src.util import (
foreach,
merge_lists,
partition_list,
safe_map,
safe_zip,
split_dict,
split_list,
unzip2,
weakref_lru_cache,
)
import numpy as np
## JAX utilities
map, unsafe_map = safe_map, map
zip, unsafe_zip = safe_zip, zip
PyTreeDef = tree_util.PyTreeDef
## Discharging state
# Let's say we have a jaxpr that takes in `Ref`s and outputs regular JAX values
# (`Ref`s should never be outputs from jaxprs). We'd like to convert that jaxpr
# into a "pure" jaxpr that takes in and outputs values and no longer has the
# `Read/Write/Accum` effects.
def discharge_state(jaxpr: core.Jaxpr, consts: Sequence[Any], * ,
should_discharge: bool | Sequence[bool] = True
) -> tuple[core.Jaxpr, list[Any]]:
"""Converts a jaxpr that takes in `Ref`s into one that doesn't."""
if isinstance(should_discharge, bool):
should_discharge = [should_discharge] * len(jaxpr.invars)
in_avals = [v.aval.inner_aval
if isinstance(v.aval, AbstractRef) and d
else v.aval for v, d in zip(jaxpr.invars, should_discharge)]
eval_jaxpr = lu.wrap_init(partial(_eval_jaxpr_discharge_state, jaxpr,
should_discharge, consts),
debug_info=jaxpr.debug_info)
new_jaxpr, _ , new_consts, () = pe.trace_to_jaxpr_dynamic(eval_jaxpr, in_avals)
return new_jaxpr, new_consts
@dataclasses.dataclass
class Environment:
env: dict[core.Var, Any]
def read(self, v: core.Atom) -> Any:
if type(v) is core.Literal:
return v.val
assert isinstance(v, core.Var)
return self.env[v]
def write(self, v: core.Var, val: Any) -> None:
self.env[v] = val
class DischargeRule(Protocol):
def __call__(self, in_avals: Sequence[core.AbstractValue],
out_avals: Sequence[core.AbstractValue], *args: Any,
**params: Any) -> tuple[Sequence[Any | None], Sequence[Any]]:
...
_discharge_rules: dict[core.Primitive, DischargeRule] = {}
class PartialDischargeRule(Protocol):
"""A partial discharge rule.
Exactly like a discharge rule only it accepts a `should_discharge`
argument that indicates which inputs should be discharged and the
return value returns a tuple of which the first element is the new
inputs or none but only the ones that correspond to `True` entries
in `should_charge`.
"""
def __call__(self, should_discharge: Sequence[bool],
in_avals: Sequence[core.AbstractValue],
out_avals: Sequence[core.AbstractValue], *args: Any,
**params: Any) -> tuple[Sequence[Any | None], Sequence[Any]]:
...
_partial_discharge_rules: dict[core.Primitive, PartialDischargeRule] = {}
def register_discharge_rule(prim: core.Primitive):
def register(f: DischargeRule):
_discharge_rules[prim] = f
return register
def register_partial_discharge_rule(prim: core.Primitive):
def register(f: PartialDischargeRule):
_partial_discharge_rules[prim] = f
return register
def _eval_jaxpr_discharge_state(
jaxpr: core.Jaxpr, should_discharge: Sequence[bool], consts: Sequence[Any],
*args: Any):
env = Environment({})
foreach(env.write, jaxpr.constvars, consts)
# Here some args may correspond to `Ref` avals but they'll be treated like
# regular values in this interpreter.
foreach(env.write, jaxpr.invars, args)
refs_to_discharge = {id(v.aval) for v, d in zip(jaxpr.invars, should_discharge)
if d and isinstance(v.aval, AbstractRef)}
for eqn in jaxpr.eqns:
name_stack = (
source_info_util.current_name_stack() + eqn.source_info.name_stack
)
traceback = eqn.source_info.traceback
with source_info_util.user_context(
traceback, name_stack=name_stack), eqn.ctx.manager:
should_discharge = [id(v.aval) in refs_to_discharge for v in eqn.invars]
if eqn.primitive is core.mutable_array_p:
[invar], [outvar] = eqn.invars, eqn.outvars
ans = env.read(invar)
refs_to_discharge.add(id(outvar.aval))
elif eqn.primitive is core.freeze_p:
[invar], [outvar] = eqn.invars, eqn.outvars
ans = env.read(invar)
refs_to_discharge.remove(id(invar.aval))
elif (any(should_discharge)
or core.internal_mutable_array_effect in eqn.effects
):
if eqn.primitive in _partial_discharge_rules:
rule: DischargeRule = partial(_partial_discharge_rules[eqn.primitive], should_discharge)
elif eqn.primitive in _discharge_rules:
rule = _discharge_rules[eqn.primitive]
else:
raise NotImplementedError("No state discharge rule implemented for "
f"primitive: {eqn.primitive}")
invals = map(env.read, eqn.invars)
in_avals = [v.aval for v in eqn.invars]
out_avals = [v.aval for v in eqn.outvars]
new_invals, ans = rule(
in_avals, out_avals, *invals, **eqn.params)
for invar, should, new_inval in zip(eqn.invars, should_discharge, new_invals):
if new_inval is not None:
if not should:
raise ValueError(
f"Did not ask for inval to be discharged but it was. ({invar=},"
f" {new_inval=})"
)
env.write(invar, new_inval) # type: ignore[arg-type]
else:
# Default primitive rule, similar to `core.eval_jaxpr`. Note that here
# we assume any higher-order primitives inside of the jaxpr are *not*
# stateful.
subfuns, bind_params = eqn.primitive.get_bind_params(eqn.params)
ans = eqn.primitive.bind(*subfuns, *map(env.read, eqn.invars),
**bind_params)
if eqn.primitive.multiple_results:
foreach(env.write, eqn.outvars, ans)
else:
env.write(eqn.outvars[0], ans)
# By convention, we return the outputs of the jaxpr first and then the final
# values of the `Ref`s. Callers to this function should be able to split
# them up by looking at `len(jaxpr.outvars)`.
out_vals = map(env.read, jaxpr.outvars)
ref_vals = map(
env.read, [v for v in jaxpr.invars if id(v.aval) in refs_to_discharge])
return out_vals + ref_vals
def _is_trivial_indexer(indexer: indexing.NDIndexer):
"""Returns whether the indexer selects the entire shape."""
for s, idx in zip(indexer.shape, indexer.indices):
if not isinstance(idx, indexing.Slice):
return False
if idx.is_dynamic_start or idx.is_dynamic_size:
return False
if idx.start != 0 or idx.size != s:
return False
return True
def _maybe_convert_to_slice(
indexer: indexing.NDIndexer
) -> list[tuple[int, int, int]] | None:
args = []
for i in indexer.indices:
if not isinstance(i, indexing.Slice):
return None
start = i.start
end = i.start + (i.size - 1) * i.stride + 1
stride = i.stride
# cannot convert to static `slice` if `start` or `end` is dynamic
if not isinstance(start, int) or not isinstance(end, int):
return None
args.append((start, end, stride))
return args
def _maybe_convert_to_dynamic_slice(
indexer: indexing.NDIndexer,
) -> (
tuple[tuple[Array | int, ...], tuple[Array | int, ...], tuple[int, ...]]
| None
):
# An NDIndexer only corresponds to a `dynamic_slice` or `dynamic_update_slice`
# if each of the indexers is a `Slice` or a ()-shaped value.
if not all(isinstance(i, indexing.Slice) or not np.shape(i)
for i in indexer.indices):
return None
# `lax.dynamic_slice` does not handle striding
for i in indexer.indices:
if isinstance(i, indexing.Slice) and i.stride > 1:
return None
_convert_i32 = lambda x: lax.convert_element_type(x, np.dtype("int32"))
starts = tuple(
_convert_i32(i.start) if isinstance(i, indexing.Slice)
else _convert_i32(i) for i in indexer.indices
)
sizes = tuple(
i.size if isinstance(i, indexing.Slice) else 1 for i in indexer.indices
)
squeeze_dims = tuple(
i
for i, idx in enumerate(indexer.indices)
if not isinstance(idx, indexing.Slice)
)
return starts, sizes, squeeze_dims
# In this code, indexing is handled in three ways: `slice`, `dynamic_slice`, and
# gather. For the gather case, the goal is to create a gather array, which means
# that we need to convert all other types of indexers into integer array
# indexers. This is done by looping over all indexers and checking if they are
# not integer array indexers, and if not, performing the conversion. However,
# during this process, the indexing semantics may change. Specifically,
# according to the indexing rules of NumPy, when there are integer array
# indexers separated by other indexers, the axes corresponding to the integer
# array indexers need to be moved to the front. After we convert all other
# indexers to integer array indexers, the distinction between integer array
# indexers and other types of indexers is lost. As a result, it becomes
# impossible to determine which axes should be moved to the front. In this case,
# we need to transpose the target array before the gather operation. We also
# need to transpose the target array back after the gather operation, if it is
# used in subsequent computations.
def _maybe_transpose_before_gather(
indexer: indexing.NDIndexer
) -> tuple[int, ...] | None:
is_int_indexing, _, _ = indexing.unpack_ndindexer(indexer)
int_indexers_contiguous = bool(
np.all(np.diff(np.where(is_int_indexing)[0]) == 1)
)
if int_indexers_contiguous:
return None # no transpose needed
int_indexer_idxs: list[int] = []
non_int_indexer_idxs: list[int] = []
for i, is_int_index in enumerate(is_int_indexing):
(int_indexer_idxs if is_int_index else non_int_indexer_idxs).append(i)
transpose_order = (*int_indexer_idxs, *non_int_indexer_idxs)
return transpose_order
def _perform_transpose_before_gather(
target_arr: Array,
indexer: indexing.NDIndexer,
transpose_order: tuple[int, ...],
) -> tuple[Array, indexing.NDIndexer]:
new_target_arr = target_arr.transpose(transpose_order)
reordered_indices = tuple(indexer.indices[i] for i in transpose_order)
new_indexer = indexing.NDIndexer(
indices=reordered_indices,
shape=indexer.shape,
int_indexer_shape=indexer.int_indexer_shape,
)
return new_target_arr, new_indexer
def _convert_to_gather_arrays(indexer: indexing.NDIndexer) -> tuple[Array, ...]:
# This is the general gather case. We need to create the gather arrays.
total_shape = indexer.get_indexer_shape()
is_int_indexing, _, _ = indexing.unpack_ndindexer(indexer)
if any(is_int_indexing):
n_idxers = len(indexer.indices)
int_indexer_shape = indexer.int_indexer_shape
n_int_indexers = sum(1 for p in is_int_indexing if p)
last_int_index_idx = n_idxers - 1 - is_int_indexing[::-1].index(True)
n_slice_index_dims_after_int = n_idxers - last_int_index_idx - 1
def get_idx_in_shape_after_indexing(i):
if not any(is_int_indexing):
return i
if i < n_idxers - n_slice_index_dims_after_int - n_int_indexers:
return i
if i < n_idxers - n_slice_index_dims_after_int:
raise ValueError
return i - n_int_indexers + len(int_indexer_shape)
arrs = []
for i, idxer in enumerate(indexer.indices):
if isinstance(idxer, indexing.Slice):
idx_in_shape_after_indexing = get_idx_in_shape_after_indexing(i)
arr = (
lax.iota(np.int32, total_shape[idx_in_shape_after_indexing])
* idxer.stride
+ idxer.start
)
diff = len(total_shape) - idx_in_shape_after_indexing - 1
arr = arr.reshape(arr.shape + (1,) * diff)
arrs.append(arr)
elif isinstance(idxer, (np.ndarray, Array)):
diff = n_idxers - 1 - last_int_index_idx
arr = idxer.reshape(idxer.shape + (1,) * diff)
arrs.append(arr)
else:
raise ValueError(f"Invalid type of idxer: {type(idxer).__name__}")
return tuple(arrs)
@register_discharge_rule(get_p)
def _get_discharge_rule(
in_avals: Sequence[core.AbstractValue],
out_avals: Sequence[core.AbstractValue], x, *idx,
tree):
del in_avals, out_avals
y = _get_discharge(x, idx, tree)
return (None,) * (len(idx) + 1), y
def _index_array(x, indexer: indexing.NDIndexer):
if _is_trivial_indexer(indexer):
return x
# Try the three APIs in the following order: `lax.slice`,
# `lax.dynamic_slice` and gather
if maybe_slice := _maybe_convert_to_slice(indexer):
x = lax_slicing.slice(x, *zip(*maybe_slice))
# If everything in the indexer is a slice or ()-shaped, we can also
# use `lax.dynamic_slice` with 1-sized slices for ()-shaped indices.
# We need to squeeze out the 1-sized slices at the end.
elif maybe_dynamic_slice := _maybe_convert_to_dynamic_slice(indexer):
starts, sizes, squeeze_dims = maybe_dynamic_slice
y = lax_slicing.dynamic_slice(x, starts, sizes)
x = lax.squeeze(y, squeeze_dims)
else:
transpose_order = _maybe_transpose_before_gather(indexer)
if transpose_order is not None:
x, indexer = _perform_transpose_before_gather(x, indexer, transpose_order)
arrays = _convert_to_gather_arrays(indexer)
x = x[arrays]
return x
def transform_array(x, transforms):
if transforms is None:
transforms = []
result = x
for transform in transforms:
if transform is None:
continue
match transform:
case indexing.NDIndexer():
result = _index_array(result, transform)
case RefBitcaster():
result = bitcast(result, transform.dtype)
case RefReshaper():
result = result.reshape(transform.shape)
case _:
raise NotImplementedError(f"Unsupported transform: {transform}")
return result
def transform_swap_array(x, transforms, val):
if transforms is None:
transforms = []
# Will hold the value read from `x` before the swap, and will have the same
# shape as `val`.
new_val = x
# List of intermediate results by transforming `x`.
intermediates = [x]
# Read phase (forward loop)
for transform in transforms:
match transform:
case indexing.NDIndexer():
indexer = transform
if _is_trivial_indexer(indexer):
intermediates.append(intermediates[-1])
continue
# If everything in the indexer is a slice or ()-shaped, we can also
# use `lax.dynamic_slice` with 1-sized slices for ()-shaped indices.
# We need to squeeze out the 1-sized slices at the end.
if maybe_slice := _maybe_convert_to_dynamic_slice(indexer):
starts, sizes, squeeze_dims = maybe_slice
new_val = lax.squeeze(
lax_slicing.dynamic_slice(new_val, starts, sizes), squeeze_dims
)
else:
transpose_order = _maybe_transpose_before_gather(indexer)
if transpose_order is not None:
new_val, indexer = _perform_transpose_before_gather(
new_val, indexer, transpose_order
)
arrays = _convert_to_gather_arrays(indexer)
new_val = new_val[arrays]
# Here, we don't need to transpose `new_val` back because it now holds
# the result of the indexing, and is no longer the original array that
# was indexed into.
intermediates.append(new_val)
case RefBitcaster():
intermediates.append(bitcast(new_val, transform.dtype))
case RefReshaper():
intermediates.append(new_val.reshape(transform.shape))
case _:
raise NotImplementedError(f"Unsupported transform: {transform}")
# Will hold the final state of the `x` after `val` has been written to the
# transformed location, and will have the same shape as `x`.
new_x = val
# Write phase (reversed loop)
for intermediate, transform in reversed(zip(intermediates[:-1], transforms)):
if isinstance(transform, indexing.NDIndexer):
indexer = transform
if _is_trivial_indexer(indexer):
continue
if maybe_slice := _maybe_convert_to_dynamic_slice(indexer):
starts, _, squeeze_dims = maybe_slice
new_x = lax_slicing.dynamic_update_slice(
intermediate, lax.expand_dims(new_x, squeeze_dims), starts
)
else:
transpose_order = _maybe_transpose_before_gather(indexer)
if transpose_order is not None:
intermediate, indexer = _perform_transpose_before_gather(
intermediate, indexer, transpose_order
)
arrays = _convert_to_gather_arrays(indexer)
new_x = intermediate.at[arrays].set(new_x) # pytype: disable=attribute-error
if transpose_order is not None:
transpose_order_inversed = np.argsort(transpose_order)
new_x = new_x.transpose(transpose_order_inversed)
else:
raise NotImplementedError(f"Unsupported transform: {transform}")
return new_val, new_x
def _get_discharge(x, idx, tree):
transforms = tree_util.tree_unflatten(tree, idx)
return transform_array(x, transforms)
@register_discharge_rule(swap_p)
def _swap_discharge_rule(
in_avals: Sequence[core.AbstractValue],
out_avals: Sequence[core.AbstractValue], x, val, *idx,
tree):
del in_avals, out_avals
z, x_new = _swap_discharge(x, val, idx, tree)
return (x_new, None) + (None,) * len(idx), z
def _swap_discharge(x, val, idx, tree):
transforms = tree_util.tree_unflatten(tree, idx)
return transform_swap_array(x, transforms, val)
@register_discharge_rule(addupdate_p)
def _addupdate_discharge_rule(
in_avals: Sequence[core.AbstractValue],
out_avals: Sequence[core.AbstractValue], x, val, *idx,
tree):
del in_avals, out_avals
ans = _addupdate_discharge(x, val, idx, tree)
return (ans, None) + (None,) * len(idx), []
def _addupdate_discharge(x, val, idx, tree):
transforms = tree_util.tree_unflatten(tree, idx)
if len(transforms) > 1:
raise NotImplementedError("Only single indexer is supported.")
indexer = transforms[0]
if _is_trivial_indexer(indexer):
return x + val
# If everything in the indexer is a slice or ()-shaped, we can also
# use `lax.dynamic_slice` with 1-sized slices for ()-shaped indices.
# We need to squeeze out the 1-sized slices at the end.
if maybe_slice := _maybe_convert_to_dynamic_slice(indexer):
starts, sizes, squeeze_dims = maybe_slice
x_old = lax_slicing.dynamic_slice(x, starts, sizes)
val = lax.expand_dims(val, squeeze_dims)
y = lax_slicing.dynamic_update_slice(x, x_old + val, starts)
return y
transpose_order = _maybe_transpose_before_gather(indexer)
if transpose_order is not None:
x, indexer = _perform_transpose_before_gather(x, indexer, transpose_order)
arrays = _convert_to_gather_arrays(indexer)
x = x.at[arrays].add(val)
if transpose_order is not None:
transpose_order_inversed = np.argsort(transpose_order)
x = x.transpose(transpose_order_inversed)
return x
@weakref_lru_cache
def _cached_closed_jaxpr_discharge(closed_jaxpr: core.ClosedJaxpr):
jaxpr, consts = closed_jaxpr.jaxpr, closed_jaxpr.consts
num_outs = len(jaxpr.outvars)
discharged_jaxpr, discharged_consts = discharge_state(jaxpr, consts)
discharged_closed_jaxpr = core.ClosedJaxpr(discharged_jaxpr, discharged_consts)
fun = lu.wrap_init(core.jaxpr_as_fun(discharged_closed_jaxpr),
debug_info=discharged_jaxpr.debug_info)
return discharged_closed_jaxpr, num_outs, fun
@register_discharge_rule(core.closed_call_p)
def _closed_call_discharge_rule(
in_avals: Sequence[core.AbstractValue], _,*args,
call_jaxpr: core.ClosedJaxpr):
discharged_closed_jaxpr, num_outs, fun = _cached_closed_jaxpr_discharge(call_jaxpr)
out_and_ref_vals = core.closed_call_p.bind(fun, *args,
call_jaxpr=discharged_closed_jaxpr)
out_vals, ref_vals = split_list(out_and_ref_vals, [num_outs])
ref_vals_iter = iter(ref_vals)
new_invals = tuple(next(ref_vals_iter) if isinstance(aval, AbstractRef)
else None for aval in in_avals)
sentinel = object()
assert next(ref_vals_iter, sentinel) is sentinel
return new_invals, out_vals
# # `run_state`
run_state_p = core.Primitive("run_state")
run_state_p.multiple_results = True
def _default_initialization(x):
assert hasattr(x, 'shape')
assert hasattr(x, 'dtype')
dtype = np.dtype(x)
if np.issubdtype(dtype, np.integer):
value = np.iinfo(dtype).min
else:
value = math.nan
return lax.full(x.shape, value, dtype)
def _run_state_impl(*args: Any, jaxpr: core.Jaxpr,
which_linear: tuple[bool, ...],
is_initialized: tuple[bool, ...]):
del which_linear
discharged_jaxpr, consts = discharge_state(jaxpr, ())
# Initialize the args that are not initialized.
args_it = iter(args)
args = tuple(
next(args_it) if is_init else _default_initialization(var.aval)
for is_init, var in zip(is_initialized, discharged_jaxpr.invars)
)
return core.eval_jaxpr(discharged_jaxpr, consts, *args)
run_state_p.def_impl(_run_state_impl)
mlir.register_lowering(run_state_p, mlir.lower_fun(_run_state_impl))
def _run_state_abstract_eval(*avals: core.AbstractValue, jaxpr: core.Jaxpr,
which_linear: tuple[bool, ...],
is_initialized: tuple[bool, ...]):
del which_linear
assert sum(is_initialized) == len(avals)
# When we abstractly evaluate `run_state`, we want to keep track of which
# input avals are `Ref`s and which are not. If an aval is a `Ref`, we want to
# "propagate" out its inner effects. Otherwise, the effects are local to this
# `run_state`.
inner_to_outer_aval_mapping = {}
outer_ref_index = 0
for i, is_init in enumerate(is_initialized):
if not is_init:
pass
inner_to_outer_aval_mapping[i] = outer_ref_index
outer_ref_index += 1
nonlocal_effects = set()
is_ref = {i for i, aval in enumerate(avals) if isinstance(aval, AbstractRef)}
for eff in jaxpr.effects:
if not isinstance(eff, RefEffect):
nonlocal_effects.add(eff)
continue
if eff.input_index not in inner_to_outer_aval_mapping:
# This means that this effect corresponds to an uninitialized Ref and
# should not propagate out of the primitive.
continue
# If we do propagate the effect, we need to update the input index to
# correspond to the outer index.
outer_index = inner_to_outer_aval_mapping[eff.input_index]
if outer_index in is_ref:
# This means that the effect corresponds to a Ref from an outside scope.
nonlocal_effects.add(
eff.replace(input_index=inner_to_outer_aval_mapping[eff.input_index])
)
assert len(jaxpr.invars) == len(is_initialized)
if not all(is_initialized):
raise NotImplementedError # Uninitialized refs are not in avals.
return avals, nonlocal_effects
run_state_p.def_effectful_abstract_eval(_run_state_abstract_eval)
def _run_state_jvp(primals: Sequence[Any], tangents: Sequence[Any], *,
jaxpr: core.Jaxpr, which_linear: tuple[bool, ...],
is_initialized: tuple[bool, ...]):
if not all(is_initialized):
raise NotImplementedError("Uninitialized Refs are not supported in jvp.")
nonzero_tangents = [not isinstance(t, ad_util.Zero) for t in tangents]
discharged_jaxpr, body_consts = discharge_state(jaxpr, ())
for _ in range(len(nonzero_tangents)):
_, out_nonzero_tangents = ad.jvp_jaxpr(
core.ClosedJaxpr(discharged_jaxpr, body_consts),
nonzero_tangents, instantiate=nonzero_tangents)
if out_nonzero_tangents == nonzero_tangents:
break
nonzero_tangents = map(operator.or_, nonzero_tangents, out_nonzero_tangents)
else:
raise Exception("Invalid fixpoint")
del discharged_jaxpr, body_consts, out_nonzero_tangents
tangents = [ad.instantiate_zeros(t) if inst else t
for t, inst in zip(tangents, nonzero_tangents)]
tangents = [t for t in tangents if type(t) is not ad_util.Zero]
closed_jvp_jaxpr, _ = ad.jvp_jaxpr(pe.close_jaxpr(jaxpr),
nonzero_tangents, [])
jvp_jaxpr_, jvp_consts = closed_jvp_jaxpr.jaxpr, closed_jvp_jaxpr.consts
jvp_jaxpr = hoist_consts_to_refs(jvp_jaxpr_)
jvp_which_linear = (*(False,) * len(jvp_consts), *which_linear, *(True,) * len(tangents))
out = run_state_p.bind(*jvp_consts, *primals, *tangents, jaxpr=jvp_jaxpr,
which_linear=jvp_which_linear,
# TODO(sharadmv): compute this in the general case
is_initialized=(True,) * len(jvp_jaxpr.invars))
out_consts, out_primals, out_tangents = split_list(out, [len(jvp_consts),
len(primals)])
del out_consts
out_tangents_iter = iter(out_tangents)
out_tangents = [next(out_tangents_iter) if nz else ad_util.Zero.from_primal_value(p)
for p, nz in zip(out_primals, nonzero_tangents)]
return out_primals, out_tangents
ad.primitive_jvps[run_state_p] = _run_state_jvp
_save_everything = lambda *_, **__: True
def _convert_outputs_to_writes(
jaxpr: core.Jaxpr) -> tuple[core.Jaxpr, list[core.ShapedArray]]:
assert not jaxpr.constvars, "Jaxpr shouldn't have constvars."
in_avals = [v.aval for v in jaxpr.invars]
def eval_jaxpr(*refs):
# We split the refs into the original input refs and the dummy residual
# refs.
orig_refs, residual_refs = split_list(refs, [len(in_avals)])
residual_vals = core.eval_jaxpr(jaxpr, (), *orig_refs)
for res_ref, res_val in zip(residual_refs, residual_vals):
res_ref[...] = res_val
return []
res_ref_avals = [AbstractRef(v.aval) if not isinstance(v.aval, AbstractRef)
else v.aval for v in jaxpr.outvars]
jaxpr, _, consts, () = pe.trace_to_jaxpr_dynamic(
lu.wrap_init(eval_jaxpr,
debug_info=jaxpr.debug_info),
[*in_avals, *res_ref_avals])
assert not consts
return jaxpr, [core.ShapedArray(a.shape, a.dtype) for a in res_ref_avals]
def _convert_inputs_to_reads(num_res: int, jaxpr: core.Jaxpr) -> core.Jaxpr:
assert not jaxpr.constvars, "Jaxpr should not have constvars"
def eval_jaxpr(*refs):
residual_refs, orig_refs = split_list(refs, [num_res])
residual_vals = [r[...] for r in residual_refs]
() = core.eval_jaxpr(jaxpr, (), *residual_vals, *orig_refs)
return []
res_val_avals, orig_ref_avals = \
split_list([v.aval for v in jaxpr.invars], [num_res])
res_ref_avals = [AbstractRef(aval) if not isinstance(aval, AbstractRef) else
aval for aval in res_val_avals]
jaxpr, _, (), () = pe.trace_to_jaxpr_dynamic(
lu.wrap_init(eval_jaxpr,
debug_info=jaxpr.debug_info),
[*res_ref_avals, *orig_ref_avals])
return jaxpr
def _run_state_partial_eval(trace: pe.JaxprTrace, *tracers: pe.JaxprTracer,
jaxpr: core.Jaxpr, which_linear: tuple[bool, ...],
is_initialized: tuple[bool, ...]):
if not all(is_initialized):
raise NotImplementedError(
"Uninitialized Refs are not supported in partial_eval."
)
num_inputs = len(tracers)
assert num_inputs == len(jaxpr.invars)
in_unknowns = [not t.pval.is_known() for t in tracers]
# We first need to run a fixpoint to determine which of the `Ref`s are unknown
# after running the for loop. We want to use the jaxpr to determine which
# `Ref`s are unknown after executing the for loop body given which `Ref`s are
# unknown before. However, the jaxpr has no outputs. Instead, we discharge
# the body and run the fixpoint with the discharged jaxpr. We can do this
# because the outputs of the jaxpr are one-to-one with the inputs.
discharged_jaxpr_, discharged_consts = discharge_state(jaxpr, ())
discharged_jaxpr = pe.convert_constvars_jaxpr(discharged_jaxpr_)
for _ in range(num_inputs):
jaxpr_in_unknowns = [False] * len(discharged_consts) + in_unknowns
_, _, out_unknowns, out_inst, _, _ = pe.partial_eval_jaxpr_stateful(
discharged_jaxpr, jaxpr_in_unknowns, jaxpr_in_unknowns,
in_unknowns, False, _save_everything)
# assert out_inst == out_unknowns
out_unknowns = list(out_unknowns)
if out_unknowns == in_unknowns:
break
in_unknowns = map(operator.or_, in_unknowns, out_unknowns)
else:
raise Exception("Invalid fixpoint")
del out_unknowns # redundant since it's the same as `in_unknowns`
tracers = tuple(trace.instantiate_const(t) if uk else t
for t, uk in zip(tracers, in_unknowns))
# We use `partial_eval_jaxpr_stateful` here because it won't remove effectful
# primitives like `get`/`set`.
jaxpr_known_resout, jaxpr_unknown_resin_, _, _, num_res_out, num_res_ref = \
pe.partial_eval_jaxpr_stateful(jaxpr, in_unknowns, in_inst=in_unknowns,
ensure_out_unknowns=[], ensure_out_inst=[],
saveable=_save_everything)
# # `partial_eval_jaxpr_stateful` will give us jaxprs that have hybrid `Ref`
# and regular valued input/outputs. However, we'd like to bind these jaxprs to
# a `for`, which expects only `Ref` inputs and no output. We need to convert
# both of these jaxprs into ones that are compatible with `for`.
# `jaxpr_known_resout` is a jaxpr that maps from all the input `Refs`
# to output residual values (none of them should be `Ref`s). We'll need to
# convert the output residual values into `Ref`s that are initially empty
# `Ref`s that are written to at the end of the jaxpr.
num_res = num_res_out + num_res_ref
num_invars = len(jaxpr_known_resout.invars) - num_res_ref
_, res_ref_avals = split_list(
[v.aval for v in jaxpr_known_resout.invars], [num_invars])
res_avals = [a.inner_aval for a in res_ref_avals] # pytype: disable=attribute-error
jaxpr_known, new_res_avals = _convert_outputs_to_writes(jaxpr_known_resout)
# We now run the known jaxpr to obtain our residual values.
known_tracers, _ = partition_list(in_unknowns, tracers)
known_which_linear, _ = partition_list(in_unknowns, which_linear)
known_vals = [t.pval.get_known() for t in known_tracers]
all_res_avals = [*res_avals, *new_res_avals]
empty_res = map(ad_util.zeros_like_aval, all_res_avals)
jaxpr_known_args = [*known_vals, *empty_res]
jaxpr_known_which_linear = (*known_which_linear, *(False,) * num_res)
out_flat = run_state_p.bind(*jaxpr_known_args, jaxpr=jaxpr_known,
which_linear=jaxpr_known_which_linear,
# TODO(sharadmv): compute this in the general case
is_initialized=(True,) * len(jaxpr_known.invars))
known_outputs, residuals = split_list(out_flat, [len(known_tracers)])
residuals = map(trace.new_instantiated_const, residuals)
ref_res, nonref_res = split_list(residuals, [num_res_ref])
# Now we handle the `jaxpr_unknown` that expects residual values as inputs.
# This jaxpr is the output of `partial_eval_jaxpr_stateful` that marks which
# inputs are actually used.
# `partial_eval_jaxpr_stateful` doesn't remove extra inputs/outputs for you
# so we use `dce_jaxpr` here to do that.
# To make it compatible with `for`, we need to convert those residual values
# into `Ref`s.
jaxpr_unknown = _convert_inputs_to_reads(len(new_res_avals),
jaxpr_unknown_resin_)
_, unknown_tracers = partition_list(in_unknowns, tracers)
_, uk_which_linear = partition_list(in_unknowns, which_linear)
unknown_which_linear = (False,) * num_res + tuple(uk_which_linear)
unknown_inputs = [*nonref_res, *ref_res, *unknown_tracers]
# Outputs match inputs so we construct output tracers that look like the input
# tracers.
res_ref_unknown_outputs = [
pe.JaxprTracer(trace, pe.PartialVal.unknown(t.aval), None)
for t in unknown_inputs]
name_stack = source_info_util.current_name_stack()[len(trace.name_stack):]
source = source_info_util.current().replace(name_stack=name_stack)
assert len(unknown_inputs) == len(res_ref_unknown_outputs)
assert len(unknown_inputs) == len(jaxpr_unknown.invars)
uk_params = dict(jaxpr=jaxpr_unknown, which_linear=unknown_which_linear,
# TODO(sharadmv); compute this in the general case
is_initialized=(True,) * len(jaxpr_unknown.invars))
_, eqn_effects = run_state_p.abstract_eval(*[v.aval for v in unknown_inputs],
**uk_params)
eqn = pe.new_eqn_recipe(trace, unknown_inputs, res_ref_unknown_outputs,
run_state_p, uk_params,
eqn_effects, source)
for t in res_ref_unknown_outputs: t.recipe = eqn
_, unknown_outputs = split_list(res_ref_unknown_outputs, [num_res])
return merge_lists(in_unknowns, known_outputs, unknown_outputs)
pe.custom_partial_eval_rules[run_state_p] = _run_state_partial_eval
def _run_state_partial_eval_custom(
saveable: Callable[..., pe.RematCases_],
in_unknowns: Sequence[bool],
in_inst: Sequence[bool],
eqn: core.JaxprEqn):
if not any(in_unknowns):
return eqn, None, in_unknowns, [False] * len(in_unknowns), []
jaxpr, which_linear, is_initialized = split_dict(
eqn.params, ["jaxpr", "which_linear", "is_initialized"]
)
if not all(is_initialized):
raise NotImplementedError(
"Uninitialized Refs are not supported in partial_eval_custom."
)
num_inputs = len(eqn.invars)
# We first need to run a fixpoint to determine which of the `Ref`s are unknown
# after running the for loop. However, the jaxpr has no outputs. Instead, we
# discharge the body and run the fixpoint with the discharged jaxpr. We can do
# this because the outputs of the discharged jaxpr are one-to-one with the
# inputs.
discharged_jaxpr, discharged_consts = discharge_state(jaxpr, ())
discharged_jaxpr = discharged_jaxpr.replace(
invars=discharged_jaxpr.constvars + discharged_jaxpr.invars,
constvars=[])
in_unknowns, in_inst = list(in_unknowns), list(in_inst)
out_unknowns, out_inst = in_unknowns, in_unknowns
for _ in range(num_inputs):
jaxpr_in_unknowns = [False] * len(discharged_consts) + in_unknowns
_, _, out_unknowns, out_inst, _, _ = pe.partial_eval_jaxpr_stateful(
discharged_jaxpr,
in_unknowns=jaxpr_in_unknowns,
in_inst=jaxpr_in_unknowns,
ensure_out_unknowns=in_unknowns,
ensure_out_inst=in_unknowns,
saveable=saveable)
out_unknowns = list(out_unknowns)
if out_unknowns == in_unknowns:
break
in_unknowns = map(operator.or_, in_unknowns, out_unknowns)
else:
if num_inputs > 0:
raise Exception("Invalid fixpoint")
del out_unknowns # Redundant since it's the same as `in_unknowns`
new_inst = [x for x, already, inst in zip(eqn.invars, in_inst, out_inst)
if type(x) is core.Var and inst and not already]
# We use `partial_eval_jaxpr_stateful` here because it won't remove effectful
# primitives like `get`/`set`.
jaxpr_known_resout, jaxpr_staged_resin_, _, _, num_res_out, num_res_ref = \
pe.partial_eval_jaxpr_stateful(jaxpr, in_unknowns,
in_unknowns, [], [], saveable)
num_res = num_res_ref + num_res_out
# `partial_eval_jaxpr_stateful` will give us jaxprs that have hybrid `Ref` and
# non-Ref input/outputs. However, we'd like to bind these jaxprs to a
# `for`, which expects only `Ref` inputs and no output. We need to convert
# both of these jaxprs into ones that are compatible with `for`.
# TODO(sharadmv,mattjj): implement "passthrough" optimization.
# `jaxpr_known_resout` is a jaxpr that maps from all the input `Refs`
# to output residual values (none of them should be `Ref`s). We'll need to
# convert the output residual values into `Ref`s that are initially empty
# `Ref`s that are written to at the end of the jaxpr.
jaxpr_known, res_avals = _convert_outputs_to_writes(jaxpr_known_resout)
# In a stateful partial_eval, the residuals should be `Ref`s.
res_avals = map(AbstractRef, res_avals)
known_invars, staged_invars = partition_list(in_unknowns, eqn.invars)
known_outvars, staged_outvars = partition_list(in_unknowns, eqn.outvars)
newvar = core.gensym()
_, res_ref_avals = split_list([v.aval for v in jaxpr_known_resout.invars],
[len(known_invars)])
nonref_resvars = map(newvar, res_avals)
ref_resvars = map(newvar, res_ref_avals)
known_out_resvars = map(newvar, [*res_ref_avals, *res_avals])
known_which_linear, _ = partition_list(in_unknowns, which_linear)
jaxpr_known_which_linear = (*known_which_linear, *(False,) * num_res)
known_and_res_invars = [*known_invars, *ref_resvars, *nonref_resvars]
known_params = dict(jaxpr=jaxpr_known, which_linear=jaxpr_known_which_linear,
# TODO(sharadmv): compute this in the general case
is_initialized=(True,) * len(jaxpr_known.invars))
_, known_effects = run_state_p.abstract_eval(
*[v.aval for v in known_and_res_invars], **known_params)
eqn_known = pe.new_jaxpr_eqn(known_and_res_invars,
[*known_outvars, *known_out_resvars],
run_state_p, known_params,
known_effects, eqn.source_info, eqn.ctx)
jaxpr_staged = _convert_inputs_to_reads(len(res_avals), jaxpr_staged_resin_)
_, staged_which_linear = partition_list(in_unknowns, which_linear)
which_linear_unknown = (*[False] * num_res, *staged_which_linear)
staged_params = dict(jaxpr=jaxpr_staged, which_linear=which_linear_unknown,
# TODO(sharadmv): compute this in the general case
is_initialized=(True,) * len(jaxpr_staged.invars))
rejiggered_resvars = [*nonref_resvars, *ref_resvars]
_, staged_invars = partition_list(in_unknowns, eqn.invars)
res_staged_invars = [*rejiggered_resvars, *staged_invars]
_, staged_effects = run_state_p.abstract_eval(
*[v.aval for v in res_staged_invars], **staged_params)
_, staged_outvars = partition_list(in_unknowns, eqn.outvars)
if num_res:
def staged(*args):
out = run_state_p.bind(*args, **staged_params)
return out[num_res:]
staged_call_jaxpr, _, (), () = pe.trace_to_jaxpr_dynamic(
lu.wrap_init(staged, debug_info=jaxpr_staged.debug_info),
[v.aval for v in res_staged_invars])
eqn_staged = pe.new_jaxpr_eqn(res_staged_invars,
staged_outvars,
core.closed_call_p,
dict(call_jaxpr=pe.close_jaxpr(staged_call_jaxpr)),
staged_effects, eqn.source_info, eqn.ctx)
assert len(res_staged_invars) == len(staged_call_jaxpr.invars)
assert len(staged_outvars) == len(staged_call_jaxpr.outvars)
else:
eqn_staged = pe.new_jaxpr_eqn(staged_invars,
staged_outvars,
run_state_p,
staged_params,
staged_effects, eqn.source_info, eqn.ctx)
new_vars = [*new_inst, *nonref_resvars, *ref_resvars]
return eqn_known, eqn_staged, in_unknowns, in_unknowns, new_vars
pe.partial_eval_jaxpr_custom_rules[run_state_p] = _run_state_partial_eval_custom
def _transpose_jaxpr(jaxpr: core.Jaxpr, which_linear: Sequence[bool],
is_initialized: tuple[bool, ...]) -> tuple[core.Jaxpr, Any]:
if not all(is_initialized):
raise NotImplementedError(
"Uninitialized Refs are not supported in transpose."
)
def trans(*args):
# First we want to run the computation to read all the residual refs. We can
# do that by using partial evaluation with all linear inputs unknown.
res_jaxpr_, tangent_jaxpr_, *_, num_res_out, num_res_ref = \
pe.partial_eval_jaxpr_stateful(jaxpr, which_linear, in_inst=which_linear,
ensure_out_inst=[],
ensure_out_unknowns=[],
saveable=_save_everything)
num_unknown = sum(which_linear)
num_known = len(jaxpr.invars) - num_unknown
res_args, _ = partition_list(which_linear, args)
res_jaxpr_avals = [v.aval for v in res_jaxpr_.invars]
_, res_avals = split_list(res_jaxpr_avals, [num_known])
res_avals = [a.inner_aval for a in res_avals] # pytype: disable=attribute-error
all_avals = [*res_avals, *[v.aval for v in res_jaxpr_.outvars]]
empty_res = map(ad.zeros_like_aval, all_avals)
res_jaxpr, _ = _convert_outputs_to_writes(res_jaxpr_)
res = run_state_p.bind(
*res_args,
*empty_res,
jaxpr=res_jaxpr,
which_linear=(False,) * (len(res_args) + len(empty_res)),
# TODO(sharadmv): compute this in the general case
is_initialized=(True,) * len(res_jaxpr.invars),
)
res = res[len(res_args):]
ref_res_, nonref_res_ = split_list(res, [num_res_ref])
# Now that we have residual values, we run the tangent jaxpr. It takes as
# input the residuals, the loop index, and all the refs (at least, the ones
# that are used in the body). Luckily, `tangent_jaxpr_` has all known and
# unknown inputs!
tangent_jaxpr, used_inputs = pe.dce_jaxpr(tangent_jaxpr_, [])
used_res, used_cts = split_list(used_inputs, [len(res)])
used_nonref_res, used_ref_res = split_list(used_res, [num_res_out])
_, nonref_res = partition_list(used_nonref_res, nonref_res_)
_, ref_res = partition_list(used_ref_res, ref_res_)
primals_args = [*nonref_res, *ref_res]
_, tangent_args = partition_list(which_linear, args)
_, ct_args = partition_list(used_cts, tangent_args)
ad.backward_pass(tangent_jaxpr, False, (), (*primals_args, *ct_args), ())
return []
jaxpr_trans, _, consts, () = pe.trace_to_jaxpr_dynamic(
lu.wrap_init(trans,
debug_info=jaxpr.debug_info),
[v.aval for v in jaxpr.invars])
return jaxpr_trans, consts
def _run_state_transpose(in_cts, *args, jaxpr: core.Jaxpr,
which_linear: tuple[bool, ...],
is_initialized: tuple[bool, ...]):
if not all(is_initialized):
raise NotImplementedError(
"Uninitialized Refs are not supported in transpose."
)
# if any in_ct is nonzero, we definitely want it in args_ (and the
# corresponding x in args could be an undefined primal, but doesn't have to be)
# for non-res stuff:
# getting and setting => (nonzero ct, UndefinedPrimal arg)
# just setting => (nonzero ct, not UndefinedPrimal, dummy value)
# just getting => (zero ct , UndefinedPrimal arg)
# for res stuff:
# (zero ct , not UndefinedPrimal)
assert any(which_linear)
transpose_args = []
for x, ct in zip(args, in_cts):
if type(ct) is ad_util.Zero and not ad.is_undefined_primal(x):
# this is a residual, take x!
transpose_args.append(x)
elif type(ct) is ad_util.Zero and ad.is_undefined_primal(x):
# the loop was 'just getting', plug in a zero
transpose_args.append(ad_util.zeros_like_aval(x.aval))
elif type(ct) is not ad_util.Zero and not ad.is_undefined_primal(x):
# the loop was 'just setting', grab that cotangent! x is dummy
transpose_args.append(ct)
elif type(ct) is not ad_util.Zero and ad.is_undefined_primal(x):
# the loop was 'getting and setting', grab that cotangent!
transpose_args.append(ct)
jaxpr_transpose_, consts = _transpose_jaxpr(
jaxpr, which_linear, is_initialized
)
jaxpr_transpose = hoist_consts_to_refs(jaxpr_transpose_)
which_linear = (*[False] * len(consts), *which_linear)
const_all_outs = run_state_p.bind(
*consts,
*transpose_args,
jaxpr=jaxpr_transpose,
which_linear=which_linear,
# TODO(sharadmv): compute this in the general case
is_initialized=(True,) * len(jaxpr_transpose.invars),
)
_, all_outs = split_list(const_all_outs, [len(consts)])
ct_outs = [ct if ad.is_undefined_primal(x) else None
for x, ct in zip(args, all_outs)]
return ct_outs
ad.primitive_transposes[run_state_p] = _run_state_transpose
@register_discharge_rule(run_state_p)
def _run_state_discharge_rule(in_avals: Sequence[core.AbstractValue],
out_avals: Sequence[core.AbstractValue],
*args: Any, jaxpr: core.Jaxpr,
which_linear: Sequence[bool],
is_initialized: tuple[bool, ...]):
if not all(is_initialized):
raise NotImplementedError(
"Uninitialized Refs are not supported in discharge."
)
del out_avals
out_vals = run_state_p.bind(*args, jaxpr=jaxpr, which_linear=which_linear,
is_initialized=is_initialized)
new_invals = []
for aval, out_val in zip(in_avals, out_vals):
new_invals.append(out_val if isinstance(aval, AbstractRef) else None)
return new_invals, out_vals
def initial_style_jaxpr(
fun: Callable, in_tree: PyTreeDef, in_avals: Sequence[core.AbstractValue],
dbg: core.DebugInfo,
) -> tuple[core.Jaxpr, list[Any], PyTreeDef]:
return _initial_style_jaxpr(fun, in_tree, tuple(in_avals), dbg)
@weakref_lru_cache
def _initial_style_jaxpr(fun: Callable,
in_tree: api_util.PyTreeDef,
in_avals: Sequence[core.AbstractValue],
debug: core.DebugInfo):
fun_, out_tree_thunk = api_util.flatten_fun_nokwargs(
lu.wrap_init(fun, debug_info=debug),
tree_util.treedef_tuple((in_tree,)))
jaxpr, _, consts, () = pe.trace_to_jaxpr_dynamic(fun_, in_avals)
return jaxpr, consts, out_tree_thunk()
T = TypeVar('T')
def run_state(f: Callable[..., None]) -> Callable[[T], T]:
def wrapped(args):
dbg = api_util.debug_info("run_state", f, (args,), {})
flat_args, in_tree = tree_util.tree_flatten(args)
ref_avals, ref_args = unzip2(map(get_ref_aval_from_value, flat_args))
# There may be some uninitialized values here in ref_args.
jaxpr_, consts, _ = initial_style_jaxpr(f, in_tree, ref_avals, dbg)
jaxpr = hoist_consts_to_refs(jaxpr_)
which_linear = (False,) * (len(consts) + len(ref_args))
refs_is_initialized = tuple(r is not uninitialized for r in ref_args)
init_args = tuple(r for r in ref_args if r is not uninitialized)
# Consts are always initialized.
is_initialized = (True,) * len(consts) + refs_is_initialized
out_const_flat = run_state_p.bind(*consts, *init_args, jaxpr=jaxpr,
which_linear=which_linear,
is_initialized=is_initialized)
_, out_flat = split_list(out_const_flat, [len(consts)])
return in_tree.unflatten(out_flat)
return wrapped
def run_state_reference(f: Callable[..., None]):
def wrapped(args):
dbg = api_util.debug_info("run_state", f, (args,), {})
flat_args, in_tree = tree_util.tree_flatten(args)
ref_avals, ref_args = unzip2(map(get_ref_aval_from_value, flat_args))
jaxpr_, consts, _ = initial_style_jaxpr(f, in_tree, ref_avals, dbg)
jaxpr = hoist_consts_to_refs(jaxpr_)
discharged_jaxpr, discharged_consts = discharge_state(jaxpr, ())
# Initialize any uninitialized values here in ref_args in the reference.
ref_args = [
_default_initialization(aval) if r is uninitialized else r
for r, aval in zip(ref_args, ref_avals)
]
out_const_flat = core.eval_jaxpr(discharged_jaxpr, discharged_consts,
*consts, *ref_args)
_, out_flat = split_list(out_const_flat, [len(consts)])
return in_tree.unflatten(out_flat)
return wrapped
@register_discharge_rule(pjit.pjit_p)
def _pjit_state_discharge_rule(
in_avals, out_avals, *args, jaxpr, in_shardings, out_shardings,
in_layouts, out_layouts, **params):
if not all(isinstance(s, sharding_impls.UnspecifiedValue) for s in (*in_shardings, *out_shardings)):
raise NotImplementedError
if not (all(l is None for l in in_layouts) and
all(l is None for l in out_layouts)):
raise NotImplementedError
jaxpr, consts = jaxpr.jaxpr, jaxpr.consts
num_outs = len(jaxpr.outvars)
discharged_jaxpr, discharged_consts = discharge_state(jaxpr, consts)
discharged_closed_jaxpr = core.ClosedJaxpr(discharged_jaxpr, discharged_consts)
new_in_shardings = (sharding_impls.UNSPECIFIED,) * len(discharged_jaxpr.invars)
new_out_shardings = (sharding_impls.UNSPECIFIED,) * len(discharged_jaxpr.outvars)
new_in_layouts = (None,) * len(discharged_jaxpr.invars)
new_out_layouts = (None,) * len(discharged_jaxpr.outvars)
out_and_ref_vals = pjit.pjit_p.bind(
*args, jaxpr=discharged_closed_jaxpr, in_shardings=new_in_shardings,
out_shardings=new_out_shardings, in_layouts=new_in_layouts,
out_layouts=new_out_layouts, **params)
out_vals, ref_vals = split_list(out_and_ref_vals, [num_outs])
ref_vals_iter = iter(ref_vals)
new_invals = tuple(next(ref_vals_iter) if isinstance(aval, AbstractRef)
else None for aval in in_avals)
sentinel = object()
assert next(ref_vals_iter, sentinel) is sentinel
return new_invals, out_vals