[jax2tf] Implement jax2tf(pjit) for experimental_native_lowering

This implementation is for the case jax2tf.convert(pjit(f_jax)),
that is, the `pjit` appears at the top-level of the function to
be lowered.
This commit is contained in:
George Necula 2022-09-06 09:32:45 +03:00
parent ff17d3d9fe
commit 9c879adb73
4 changed files with 117 additions and 45 deletions

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@ -422,6 +422,21 @@ def flatten_fun_jax(fun_jax: Callable, args_tf: Sequence[TfVal],
out_tree_ref = out_tree
return res_flat_jax
if hasattr(fun_jax, "lower"):
# If the fun_jax is already a jit(f) or pjit(f), we must
# preserve the lowering function. This will be used in the _lower_native_and_run.
# We rely on the fact that the lowering is the same for the function
# taking pytrees, and the one taking flat args.
def fun_flat_jax_lower(*args_flat_jax):
tree_args, tree_kwargs = tree_util.tree_unflatten(in_tree, args_flat_jax)
lowered = fun_jax.lower(*tree_args, **tree_kwargs)
out_tree = lowered.out_tree
nonlocal out_tree_ref
assert out_tree_ref is None or out_tree_ref == out_tree
out_tree_ref = out_tree
return lowered
setattr(fun_flat_jax, "lower", fun_flat_jax_lower)
return fun_flat_jax, args_flat_tf, in_tree, lambda: out_tree_ref
def preprocess_arg_tf(arg_idx: int,
@ -604,19 +619,24 @@ def _lower_native_and_run(fun_jax: Callable,
abstracted_axes = None # type: ignore
arg_specs_jax = [
jax.ShapeDtypeStruct(aval.shape, aval.dtype)
jax.ShapeDtypeStruct(aval.shape, aval.dtype, named_shape=aval.named_shape)
for aval in args_avals
]
# TODO: specify the backend for experimental_native_lowering
backend = jax.default_backend()
lowered = jax.jit(fun_jax, backend=backend,
keep_unused=True, # TODO: allow dropping unused
abstracted_axes=abstracted_axes).lower(*arg_specs_jax)._lowering
if not hasattr(fun_jax, "lower") or abstracted_axes:
# We support convert(pjit(f_jax, ...)) and convert(jit(f_jax)) but also
# convert(f_jax), in which case a "jit" is implied. We also add a jit when
# we need to pass the abstracted axes.
fun_jax_lower = jax.jit(fun_jax, backend=backend,
keep_unused=True, # TODO: allow dropping unused
abstracted_axes=abstracted_axes).lower
else:
fun_jax_lower = fun_jax.lower
lowered = fun_jax_lower(*arg_specs_jax)._lowering
mhlo_module = lowered.mhlo()
mhlo_module_text = mlir.module_to_string(mhlo_module)
if jaxlib.version <= (0, 3, 14):
mhlo_module_text = _fixup_mhlo_module_text(mhlo_module_text)
logging.vlog(2, f"XlaCallModule {mhlo_module_text}")
# We do not support custom_call, try to give an error for now
if "mhlo.custom_call" in mhlo_module_text:
# Try to give a nice error message. We could just dump the module...
@ -626,20 +646,25 @@ def _lower_native_and_run(fun_jax: Callable,
"work on TPU.")
custom_calls = re.findall(r'mhlo.custom_call.*call_target_name\s+=\s+"([^"]+)".*loc\(([^\)]+)\)',
mhlo_module_text)
for cc in custom_calls:
msg += f"\n{cc[0]}"
# Get the line number
m = re.search('^' + cc[1] + ' =.*', mhlo_module_text, re.MULTILINE)
if m:
msg += f"\n from line {m.group(0)}"
raise NotImplementedError(msg)
logging.vlog(2, f"XlaCallModule {mhlo_module_text}")
bad_custom_calls = tuple(filter(lambda cc: cc[0] != "Sharding", custom_calls))
if bad_custom_calls:
for cc in bad_custom_calls:
msg += f"\n{cc[0]}"
# Get the line number
m = re.search('^' + cc[1] + ' =.*', mhlo_module_text, re.MULTILINE)
if m:
msg += f"\n from line {m.group(0)}"
raise NotImplementedError(msg)
# Figure out the result types and shapes
if config.jax_array:
if "global_out_avals" in lowered.compile_args:
# This is currently the case for pjit
out_avals = lowered.compile_args["global_out_avals"]
else:
out_avals = lowered.compile_args["out_avals"]
if lowered.compile_args["host_callbacks"]:
raise NotImplementedError("host_callbacks are not yet implemented for the jax2tf native lowering")
# TODO(necula): handle d being InDBIdx
out_shapes = tuple(
tuple(d if type(d) is int else None
@ -652,12 +677,22 @@ def _lower_native_and_run(fun_jax: Callable,
return jax_type
out_types = tuple(_out_type(out_aval.dtype) for out_aval in out_avals)
# Apply the shardings on arguments and results for pjit. This is redundant
# because the mhlo_module_text will already contain the shardings, but it
# makes it easier for tools like the TPU inference converter to see the
# sharding without digging into the `module` attribute of the `XlaCallModule`
# op, in the same way as it is done for the legacy jax2tf conversion.
if "in_shardings" in lowered.compile_args:
args_tf = tuple(
map(_shard_value, args_tf, args_avals, lowered.compile_args["in_shardings"]))
res = tfxla.call_module(
args_tf,
module=mhlo_module_text,
Tout=out_types,
Sout=out_shapes,
dim_args_spec=dim_args_spec)
if "out_shardings" in lowered.compile_args:
res = list(map(_shard_value, res, out_avals, lowered.compile_args["out_shardings"]))
# Convert the results to the needed TF types
def _convert_res(res_val, res_jax_type):
@ -672,15 +707,6 @@ def _lower_native_and_run(fun_jax: Callable,
for res_val, out_aval in zip(res, out_avals))
return res, out_avals
def _fixup_mhlo_module_text(mhlo_module_text: str) -> str:
# A workaround for MHLO not (yet) having backwards compatibility. With
# jaxlib 0.3.14 we have an old serialization method that puts "..." around
# MHLO attributes. The parser is new and does not accept those attributes.
# We try to fix it up here, temporarily.
import re
return re.sub(r'#mhlo<"([^"]+)">', "#mhlo<\\1>", mhlo_module_text)
def _call_wrapped_with_new_constant_cache(fun: lu.WrappedFun,
in_vals: Sequence[TfVal],
fresh_constant_cache: bool = False

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@ -12,6 +12,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
"""Tests for the jax2tf conversion for control-flow primitives."""
import unittest
from absl.testing import absltest
@ -29,6 +30,12 @@ config.parse_flags_with_absl()
class ControlFlowOpsTest(tf_test_util.JaxToTfTestCase):
def setUp(self):
super().setUp()
# TODO(b/252947617): re-enable these tests
if config.jax_array and config.jax2tf_default_experimental_native_lowering:
raise unittest.SkipTest("Test disabled for JAX_ARRAY")
@jtu.ignore_warning(category=UserWarning,
message="Explicitly requested dtype .* requested in array is not available")
def test_cond(self):

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@ -51,6 +51,12 @@ config.parse_flags_with_absl()
class Jax2TfTest(tf_test_util.JaxToTfTestCase):
def setUp(self):
super().setUp()
# TODO(b/252943725): re-enable these tests
if config.jax_array and config.jax2tf_default_experimental_native_lowering:
raise unittest.SkipTest("Test disabled for JAX_ARRAY")
def test_empty(self):
f_jax = lambda x, y: x
self.ConvertAndCompare(f_jax, 0.7, 1)
@ -117,8 +123,16 @@ class Jax2TfTest(tf_test_util.JaxToTfTestCase):
def test_nested_jit(self):
f_jax = jax.jit(lambda x: jnp.sin(jax.jit(jnp.cos)(x)))
f_tf = jax2tf.convert(f_jax)
np.testing.assert_allclose(f_jax(0.7), f_tf(0.7))
x = 0.7
self.ConvertAndCompare(f_jax, x)
def test_nested_jit_pytree(self):
@jax.jit
def f_jax(xy):
x, y = xy
return x + y
xy = (0.7, 0.8)
self.ConvertAndCompare(f_jax, xy)
def test_nested_jit_is_compiled(self):
# Check that nested jax.jit are compiled with tf.function(jit_compile=True)
@ -1241,8 +1255,17 @@ class Jax2TfTest(tf_test_util.JaxToTfTestCase):
def get_serialized_computation(
f_jax: Callable,
*args,
abstracted_axes: Optional[Tuple[Dict[int, str]]] = None) -> str:
lowered = jax.jit(f_jax, abstracted_axes=abstracted_axes).lower(*args)
abstracted_axes: Optional[Tuple[Dict[int, str]]] = None,
use_pjit: bool = False,
in_axis_resources = None,
out_axis_resources = None) -> str:
if use_pjit:
assert not abstracted_axes
lowered = pjit(f_jax,
in_axis_resources=in_axis_resources,
out_axis_resources=out_axis_resources).lower(*args)
else:
lowered = jax.jit(f_jax, abstracted_axes=abstracted_axes).lower(*args)
mhlo_module = lowered.compiler_ir(dialect='mhlo')
mhlo_module_text = mlir.module_to_string(mhlo_module)
if jaxlib.version <= (0, 3, 14):
@ -1364,23 +1387,29 @@ class XlaCallModuleTest(tf_test_util.JaxToTfTestCase):
# TODO(b/243146552) We can switch to ConvertAndCompare after this bug fix.
np.array_equal(jax_out._value, np.array(tf_out))
# Test 2: use GDA as JAX function input
def jax_func_2(input_data, params):
handle = pjit(
jnp.matmul,
in_axis_resources=(P("y", "x"), P(("x", "y"),)),
out_axis_resources=None)
return handle(input_data, params)
@jtu.with_mesh([("x", 2)])
def test_pjit_basic1D(self):
def func_jax(x, y):
return x + y
with global_mesh:
tf_func_2 = tf.function(
jax2tf.convert(jax_func_2, enable_xla=True),
jit_compile=True,
)
jax_out_2 = jax_func_2(input_data=input_data, params=params)
tf_out_2 = tf_func_2(input_data=input_data, params=params)
# TODO(b/243146552) We can switch to ConvertAndCompare after this bug fix.
np.array_equal(jax_out_2._value, np.array(tf_out_2))
shape = (8, 10)
x = np.arange(np.prod(shape), dtype=np.float32).reshape(shape)
in_axis_resources = (P("x"), P("x"))
out_axis_resources = None
res_jax = pjit(func_jax,
in_axis_resources=in_axis_resources,
out_axis_resources=out_axis_resources)(x, x)
module = get_serialized_computation(func_jax, x, x,
use_pjit=True,
in_axis_resources=in_axis_resources,
out_axis_resources=out_axis_resources)
def f_tf(x_tf, y_tf):
return tfxla.call_module([x_tf, y_tf],
module=module,
Tout=[x.dtype],
Sout=[x.shape])
res_tf = tf.function(f_tf, jit_compile=True, autograph=False)(x, x)[0]
self.assertAllClose(res_tf.numpy(), res_jax)
if __name__ == "__main__":

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@ -696,6 +696,16 @@ class ShapePolyTest(tf_test_util.JaxToTfTestCase):
dict(a="(_,)", b="(4,)")],
expected_output_signature=tf.TensorSpec([4]))
def test_with_nested_jit(self):
@jax.jit
def f_jax(x):
return jnp.sin(x)
self.CheckShapePolymorphism(
f_jax,
input_signature=[tf.TensorSpec([1, None])],
polymorphic_shapes=["1, b"])
def test_with_custom_vjp(self):
"""Shape-polymorphic custom VJP."""