def _cond_batching_rule(args, dims, true_jaxpr, false_jaxpr, true_nconsts,
false_nconsts):
# TODO: maybe avoid moving arg axes to front if we're promoting to select?
args = [batching.moveaxis(x, d, 0) if d is not batching.not_mapped and d != 0
else x for x, d in zip(args, dims)]
true_nops = len(true_jaxpr.in_avals) - true_nconsts
(pred,), true_consts, true_ops, false_consts, false_ops = split_list(
args, [1, true_nconsts, true_nops, false_nconsts])
size, = {x.shape[d] for x, d in zip(args, dims) if d is not batching.not_mapped}
orig_bat = [d is not batching.not_mapped for d in dims]
(pred_bat,), tconst_bat, t_bat, fconst_bat, f_bat = split_list(
orig_bat, [1, true_nconsts, true_nops, false_nconsts])
_, true_out_bat = batching.batch_jaxpr(true_jaxpr, size, tconst_bat + t_bat, False)
_, false_out_bat = batching.batch_jaxpr(false_jaxpr, size, fconst_bat + f_bat, False)
out_bat = [a or b for a, b in zip(true_out_bat, false_out_bat)]
true_jaxpr_batched, _ = batching.batch_jaxpr(true_jaxpr, size, tconst_bat + t_bat, out_bat)
false_jaxpr_batched, _ = batching.batch_jaxpr(false_jaxpr, size, fconst_bat + f_bat, out_bat)
if pred_bat:
true_out = core.jaxpr_as_fun(true_jaxpr_batched)(*(true_consts + true_ops))
false_out = core.jaxpr_as_fun(false_jaxpr_batched)(*(false_consts + false_ops))
true_out = [batching.broadcast(x, size, 0) if not b else x
for x, b in zip(true_out, out_bat)]
false_out = [batching.broadcast(x, size, 0) if not b else x
for x, b in zip(false_out, out_bat)]
return [_cond_pred_bcast_select(pred, t, f)
for t, f in zip(true_out, false_out)], [0] * len(true_out)
else:
out_dims = [0 if b else batching.not_mapped for b in out_bat]
return cond_p.bind(
*itertools.chain([pred], true_consts, true_ops, false_consts, false_ops),
true_jaxpr=true_jaxpr_batched, false_jaxpr=false_jaxpr_batched,
true_nconsts=len(true_consts), false_nconsts=len(false_consts)), out_dims
def _while_loop_batching_rule(args, dims, cond_nconsts, cond_jaxpr,
body_nconsts, body_jaxpr):
size, = {x.shape[d] for x, d in zip(args, dims) if d is not batching.not_mapped}
orig_batched = [d is not batching.not_mapped for d in dims]
cconst_bat, bconst_bat, init_bat = split_list(orig_batched, [cond_nconsts, body_nconsts])
carry_bat = init_bat
for _ in range(1000):
batched = bconst_bat + carry_bat
body_jaxpr_batched, carry_bat_out = batching.batch_jaxpr(
body_jaxpr, size, batched, instantiate=carry_bat)
cond_jaxpr_batched, (pred_bat,) = batching.batch_jaxpr(
cond_jaxpr, size, cconst_bat + carry_bat, instantiate=False)
carry_bat_out = _map(partial(operator.or_, pred_bat), carry_bat_out)
if carry_bat_out == carry_bat:
break
else:
carry_bat = carry_bat_out
else:
raise FixedPointError
consts, init = split_list(args, [cond_nconsts + body_nconsts])
const_dims, init_dims = split_list(dims, [cond_nconsts + body_nconsts])
new_consts = [batching.moveaxis(x, d, 0) if d is not batching.not_mapped and d != 0
else x for x, d in zip(consts, const_dims)]
new_init = [batching.broadcast(x, size, 0) if now_bat and not was_bat
else batching.moveaxis(x, d, 0) if now_bat else x
for x, d, was_bat, now_bat in zip(init, init_dims, init_bat, carry_bat)]
outs = while_p.bind(*(new_consts + new_init),
cond_nconsts=cond_nconsts, cond_jaxpr=cond_jaxpr_batched,
body_nconsts=body_nconsts, body_jaxpr=body_jaxpr_batched)
out_bdims = [0 if b else batching.not_mapped for b in carry_bat]
return outs, out_bdims
def _cond_batching_rule(axis_size, axis_name, main_type, args, dims, branches,
linear):
index, *ops = args
index_dim, *op_dims = dims
if index_dim is not batching.not_mapped:
# Convert to a lax.select. While we could get away with not broadcasting
# some operands yet, because all outputs must be broadcast together anyway
# for the select we broadcast the input operands for simplicity and leave
# optimizations to XLA.
# TODO(mattjj,frostig): assumes branches are side-effect-free, revise!
index, *ops = (batching.bdim_at_front(x, d, axis_size)
for x, d in zip(args, dims))
in_batched = [True] * len(branches[0].in_avals)
out_batched = [True] * len(branches[0].out_avals)
branches_batched = [
batching.batch_jaxpr(jaxpr, axis_size, in_batched, out_batched,
axis_name, main_type)[0] for jaxpr in branches
]
branch_outs = []
for i, jaxpr in enumerate(branches_batched):
# Perform a select on the inputs for safety of reverse-mode autodiff; see
# https://github.com/google/jax/issues/1052
predicate = lax.eq(index, lax._const(index, i))
ops_ = [
_bcast_select(predicate, x, lax.stop_gradient(x)) for x in ops
]
branch_outs.append(core.jaxpr_as_fun(jaxpr)(*ops_))
out = [_bcast_select_n(index, *outs) for outs in zip(*branch_outs)]
return out, [0 if b else None for b in out_batched]
else:
ops_bat = [d is not batching.not_mapped for d in op_dims]
ops = [
batching.moveaxis(x, d, 0) if b else x
for b, x, d in zip(ops_bat, ops, op_dims)
]
branches_out_bat = [
batching.batch_jaxpr(jaxpr, axis_size, ops_bat, False, axis_name,
main_type)[1] for jaxpr in branches
]
out_bat = [any(bat) for bat in zip(*branches_out_bat)]
branches_batched = tuple(
batching.batch_jaxpr(jaxpr, axis_size, ops_bat, out_bat, axis_name,
main_type)[0] for jaxpr in branches)
out_dims = [0 if b else batching.not_mapped for b in out_bat]
out = cond_p.bind(index,
*ops,
branches=branches_batched,
linear=linear)
return out, out_dims
def batched_jvp_jaxpr_thunk():
jvp_jaxpr = core.ClosedJaxpr(*jvp_jaxpr_thunk()) # consts can be tracers
_, args_batched = split_list(in_batched, [num_consts])
_, all_batched = batching.batch_jaxpr(jvp_jaxpr, size, args_batched * 2, False,
axis_name, main_type)
primals_batched, tangents_batched = split_list(all_batched, [num_out])
out_batched = map(op.or_, primals_batched, tangents_batched)
out_dims2.append([0 if b else not_mapped for b in out_batched])
batched_jvp_jaxpr, _ = batching.batch_jaxpr(
jvp_jaxpr, size, args_batched * 2, out_batched * 2,
axis_name, main_type)
return batched_jvp_jaxpr.jaxpr, batched_jvp_jaxpr.consts
def batched_fwd_jaxpr_thunk():
fwd_jaxpr = core.ClosedJaxpr(
*fwd_jaxpr_thunk()) # consts can be tracers
batched_fwd_jaxpr, out_batched = batching.batch_jaxpr(
fwd_jaxpr, axis_size, args_batched, False, axis_name, main_type)
out_dims2.append([0 if b else not_mapped for b in out_batched])
return batched_fwd_jaxpr.jaxpr, batched_fwd_jaxpr.consts
def _custom_vjp_call_jaxpr_vmap(
args, in_dims, axis_name, main_type, *, fun_jaxpr: core.ClosedJaxpr,
fwd_jaxpr_thunk: Callable[[], Tuple[core.Jaxpr, Sequence[Any]]],
bwd: lu.WrappedFun, out_trees: Callable, num_consts: int):
axis_size, = {x.shape[d] for x, d in zip(args, in_dims) if d is not not_mapped}
args = [batching.moveaxis(x, d, 0) if d is not not_mapped and d != 0
else x for x, d in zip(args, in_dims)]
in_batched = [d is not not_mapped for d in in_dims]
_, args_batched = split_list(in_batched, [num_consts])
batched_fun_jaxpr, out_batched = batching.batch_jaxpr(
fun_jaxpr, axis_size, in_batched, False, axis_name, main_type)
out_dims1 = [0 if b else not_mapped for b in out_batched]
out_dims2 = []
@pe._memoize
def batched_fwd_jaxpr_thunk():
fwd_jaxpr = core.ClosedJaxpr(*fwd_jaxpr_thunk()) # consts can be tracers
batched_fwd_jaxpr, out_batched = batching.batch_jaxpr(
fwd_jaxpr, axis_size, args_batched, False, axis_name, main_type)
out_dims2.append([0 if b else not_mapped for b in out_batched])
return batched_fwd_jaxpr.jaxpr, batched_fwd_jaxpr.consts
fwd_args_batched = [0 if b else not_mapped for b in args_batched]
fwd_out_dims = lambda: out_dims2[0]
batched_bwd = batching.batch_custom_vjp_bwd(bwd, axis_name, axis_size, fwd_out_dims,
fwd_args_batched, main_type)
batched_outs = custom_vjp_call_jaxpr_p.bind(
*args, fun_jaxpr=batched_fun_jaxpr,
fwd_jaxpr_thunk=batched_fwd_jaxpr_thunk, bwd=batched_bwd,
out_trees=out_trees, num_consts=num_consts)
out_dims = out_dims2[0] if out_dims2 else out_dims1
return batched_outs, out_dims
def _custom_jvp_call_jaxpr_vmap(
args, in_dims, axis_name, main_type, *, fun_jaxpr: core.ClosedJaxpr,
jvp_jaxpr_thunk: Callable[[], Tuple[core.Jaxpr, Sequence[Any]]],
num_consts: int):
size, = {x.shape[d] for x, d in zip(args, in_dims) if d is not not_mapped}
args = [batching.moveaxis(x, d, 0) if d is not not_mapped and d != 0
else x for x, d in zip(args, in_dims)]
num_out = len(fun_jaxpr.out_avals)
in_batched = [d is not not_mapped for d in in_dims]
batched_fun_jaxpr, out_batched = batching.batch_jaxpr(
fun_jaxpr, size, in_batched, False, axis_name, main_type)
out_dims1 = [0 if b else not_mapped for b in out_batched]
out_dims2 = [] # mutable cell updated by batched_jvp_jaxpr_thunk
@pe._memoize
def batched_jvp_jaxpr_thunk():
jvp_jaxpr = core.ClosedJaxpr(*jvp_jaxpr_thunk()) # consts can be tracers
_, args_batched = split_list(in_batched, [num_consts])
_, all_batched = batching.batch_jaxpr(jvp_jaxpr, size, args_batched * 2, False,
axis_name, main_type)
primals_batched, tangents_batched = split_list(all_batched, [num_out])
out_batched = map(op.or_, primals_batched, tangents_batched)
out_dims2.append([0 if b else not_mapped for b in out_batched])
batched_jvp_jaxpr, _ = batching.batch_jaxpr(
jvp_jaxpr, size, args_batched * 2, out_batched * 2,
axis_name, main_type)
return batched_jvp_jaxpr.jaxpr, batched_jvp_jaxpr.consts
batched_outs = custom_jvp_call_jaxpr_p.bind(
*args, fun_jaxpr=batched_fun_jaxpr,
jvp_jaxpr_thunk=batched_jvp_jaxpr_thunk, num_consts=num_consts)
out_dims = out_dims2[0] if out_dims2 else out_dims1
return batched_outs, out_dims
def _scan_batching_rule(args, dims, forward, length, jaxpr, num_consts,
num_carry, linear):
num_ys = len(jaxpr.out_avals) - num_carry
size, = {
x.shape[d]
for x, d in zip(args, dims) if d is not batching.not_mapped
}
orig_batched = [d is not batching.not_mapped for d in dims]
const_batched, init_batched, xs_batched = split_list(
orig_batched, [num_consts, num_carry])
carry_batched = init_batched
for _ in range(1000):
batched = const_batched + carry_batched + xs_batched
jaxpr_batched, batched_out = batching.batch_jaxpr(
jaxpr, size, batched, instantiate=carry_batched + [False] * num_ys)
carry_batched_out, ys_batched = batched_out[:num_carry], batched_out[
num_carry:]
if carry_batched_out == carry_batched:
break
else:
carry_batched = carry_batched_out
else:
raise FixedPointError
consts, init, xs = split_list(args, [num_consts, num_carry])
consts_bdims, init_bdims, xs_bdims = split_list(dims,
[num_consts, num_carry])
new_consts = [
batching.moveaxis(x, d, 0)
if d is not batching.not_mapped and d != 0 else x
for x, d in zip(consts, consts_bdims)
]
new_init = [
batching.broadcast(x, size, 0) if now_batched and not was_batched else
batching.moveaxis(x, d, 0) if now_batched else x
for x, d, was_batched, now_batched in zip(init, init_bdims,
init_batched, carry_batched)
]
new_xs = [
batching.moveaxis(x, d, 1)
if d is not batching.not_mapped and d != 1 else x
for x, d in zip(xs, xs_bdims)
]
new_args = new_consts + new_init + new_xs
outs = scan_p.bind(*new_args,
forward=forward,
length=length,
jaxpr=jaxpr_batched,
num_consts=num_consts,
num_carry=num_carry,
linear=linear)
carry_bdims = [0 if b else batching.not_mapped for b in carry_batched]
ys_bdims = [1 if b else batching.not_mapped for b in ys_batched]
return outs, carry_bdims + ys_bdims
def remat_vmap(axis_size, axis_name, main_type, args, dims, *, jaxpr, **params):
assert not jaxpr.constvars
in_batched = [d is not batching.not_mapped for d in dims]
jaxpr_ = core.ClosedJaxpr(jaxpr, ())
jaxpr_batched_, out_batched = batching.batch_jaxpr(
jaxpr_, axis_size, in_batched, instantiate=False, axis_name=axis_name,
main_type=main_type)
jaxpr_batched, consts = jaxpr_batched_.jaxpr, jaxpr_batched_.consts
out_dims = [0 if b else None for b in out_batched]
return remat_p.bind(*consts, *args, jaxpr=jaxpr_batched, **params), out_dims
def _scan_batching_rule(batched_args, batch_dims, forward, length, jaxpr):
consts, init, xs = batched_args
consts_bdim, init_bdim, xs_bdim = batch_dims
sizes = lax._reduce(set.union,
map(batching.dimsize, batch_dims, batched_args))
size = sizes.pop()
assert not sizes
consts_batched = batching.where_batched(consts_bdim)
init_batched = batching.where_batched(init_bdim)
xs_batched = batching.where_batched(xs_bdim)
carry_batched = init_batched
for _ in range(1000):
which_batched = (consts_batched, carry_batched, xs_batched)
jaxpr_batched, batched_out = batching.batch_jaxpr(
jaxpr, size, which_batched, instantiate=(carry_batched, False))
carry_batched_out, ys_batched = batched_out
if _binary_lattice_eq(carry_batched_out, carry_batched):
break
else:
carry_batched = _binary_lattice_join(carry_batched_out,
carry_batched)
else:
raise FixedPointError
consts_batched = batching.instantiate_bdim(size, 0, consts_batched,
consts_bdim, consts)
init_batched = batching.instantiate_bdim(size, 0, carry_batched, init_bdim,
init)
xs_batched = batching.instantiate_bdim(size, 1, xs_batched, xs_bdim, xs)
carry_out, ys = scan_p.bind(consts_batched,
init_batched,
xs_batched,
forward=forward,
length=length,
jaxpr=jaxpr_batched)
carry_out_bdim = batching.bools_to_bdims(0, carry_batched)
ys_bdim = batching.bools_to_bdims(1, ys_batched)
return core.pack((carry_out, ys)), (carry_out_bdim, ys_bdim)
def _linear_solve_batching_rule(axis_size, axis_name, main_type, args, dims,
const_lengths, jaxprs):
orig_bat = [d is not batching.not_mapped for d in dims]
params, b = _split_linear_solve_args(args, const_lengths)
params_dims, b_dims = _split_linear_solve_args(dims, const_lengths)
params_bat, orig_b_bat = _split_linear_solve_args(orig_bat, const_lengths)
(matvec, vecmat, solve, solve_t) = jaxprs
(matvec_bat, vecmat_bat, solve_bat, solve_t_bat) = params_bat
num_aux = len(solve.out_avals) - len(matvec.out_avals)
# Fixpoint computation of which parts of x and b are batched; we need to
# ensure this is consistent between all four jaxprs
b_bat = orig_b_bat
x_bat = [False] * len(solve.out_avals)
for i in range(1 + len(orig_b_bat) + len(solve.out_avals)):
# Apply vecmat and solve -> new batched parts of x
solve_jaxpr_batched, solve_x_bat = batching.batch_jaxpr(
solve,
axis_size,
solve_bat + b_bat,
instantiate=x_bat,
axis_name=axis_name,
main_type=main_type)
if vecmat is None:
vecmat_jaxpr_batched = None
x_bat_out = solve_x_bat
else:
vecmat_jaxpr_batched, vecmat_x_bat = batching.batch_jaxpr(
vecmat,
axis_size,
vecmat_bat + b_bat,
instantiate=x_bat,
axis_name=axis_name,
main_type=main_type)
# batch all aux data by default
x_bat_out = _map(operator.or_, vecmat_x_bat + [True] * num_aux,
solve_x_bat)
# Apply matvec and solve_t -> new batched parts of b
matvec_jaxpr_batched, matvec_b_bat = batching.batch_jaxpr(
matvec,
axis_size,
matvec_bat + x_bat_out,
instantiate=b_bat,
axis_name=axis_name,
main_type=main_type)
if solve_t is None:
solve_t_jaxpr_batched = None
b_bat_out = _map(operator.or_, matvec_b_bat, orig_b_bat)
else:
solve_t_jaxpr_batched, solve_t_b_aux_bat = batching.batch_jaxpr(
solve_t,
axis_size,
solve_t_bat + x_bat_out,
instantiate=b_bat,
axis_name=axis_name,
main_type=main_type)
assert len(solve_t_b_aux_bat) == len(orig_b_bat) + num_aux
solve_t_b_bat, _ = split_list(solve_t_b_aux_bat, [len(orig_b_bat)])
b_bat_out = _map(lambda m, s, o: m or s or o, matvec_b_bat,
solve_t_b_bat, orig_b_bat)
if x_bat_out == x_bat and b_bat_out == b_bat:
break
else:
x_bat = x_bat_out
b_bat = b_bat_out
else:
assert False, "Fixedpoint not reached"
batched_jaxprs = _LinearSolveTuple(matvec_jaxpr_batched,
vecmat_jaxpr_batched,
solve_jaxpr_batched,
solve_t_jaxpr_batched)
# Move batched axes to the front
new_params = [
batching.moveaxis(x, d, 0)
if d is not batching.not_mapped and d != 0 else x
for x, d in zip(_flatten(params), _flatten(params_dims))
]
# Broadcast out b if necessary
new_b = [
batching.broadcast(x, axis_size, 0) if now_bat and not was_bat else
batching.moveaxis(x, d, 0) if now_bat and d != 0 else x
for x, d, was_bat, now_bat in zip(b, b_dims, orig_b_bat, b_bat)
]
outs = linear_solve_p.bind(*(new_params + new_b),
const_lengths=const_lengths,
jaxprs=batched_jaxprs)
out_dims = [
0 if batched else batching.not_mapped for batched in solve_x_bat
]
return outs, out_dims
