[sharding_in_types] Default axis_types to Auto for all axis_names if user does not set any AxisType. Also resolve some TODOs now that we have a way for user to set the mesh.

PiperOrigin-RevId: 704944255

Author: yashk2810

jax/_src/core.py

@@ -1626,10 +1626,8 @@ def get_sharding(sharding, ndim):
     return _maybe_modify_sharding(sharding)
 
   context_mesh = mesh_lib.get_abstract_mesh()
-  # TODO(yashkatariya): Error out and ask users to set the context mesh in their
-  # code.
   if not context_mesh:
-    return None
+    return RuntimeError("Please set the mesh via `jax.set_mesh` API.")
   assert sharding is None
   return NamedSharding(context_mesh, P(*[None] * ndim))
 
@@ -1692,7 +1690,7 @@ def str_short(self, short_dtypes=False):
               self.dtype.name)
     dt_str = dt_str.replace('void', 'float0')
     if hasattr(self, 'sharding') and self.sharding is not None:
-      shapestr = _get_shape_sharding_str(self.shape, self.sharding.spec)
+      shapestr = _get_shape_sharding_str(self.shape, self.sharding.spec)  # type: ignore
       return f'{dt_str}[{shapestr}]'
     else:
       shapestr = ','.join(map(str, self.shape))
@@ -2658,16 +2656,10 @@ def substitute(aval: AbstractValue):
     return aval
   for v, x in zip(call_jaxpr.invars, in_atoms):
     if not typecompat(substitute(v.aval), x.aval):
-      # TODO(yashkatariya): Remove this once numpy array's aval has a sharding
-      # on it.
-      if (config.sharding_in_types.value and isinstance(x, Literal) and
-          v.aval.sharding is not None and x.val.ndim == 0):
-        pass
-      else:
-        # TODO(mattjj): vars in error message are confusing b/c of Var.__repr__
-        raise JaxprTypeError(f"Call primitive {prim} passes operand {x} of type "
-                            f"{x.aval} to jaxpr expecting type "
-                            f"{substitute(v.aval)}")
+      # TODO(mattjj): vars in error message are confusing b/c of Var.__repr__
+      raise JaxprTypeError(f"Call primitive {prim} passes operand {x} of type "
+                           f"{x.aval} to jaxpr expecting type "
+                           f"{substitute(v.aval)}")
     env[v] = x if type(x) is Var else x.val
 
   _check_jaxpr(ctx_factory, call_jaxpr)

jax/_src/mesh.py

@@ -111,8 +111,6 @@ def __repr__(self):
     return self.name
 
 def axis_names_to_types(axis_types) -> dict[str, AxisTypes]:
-  if axis_types is None:
-    return {}
   d = {}
   for t, names in axis_types.items():
     if isinstance(names, tuple):
@@ -179,7 +177,7 @@ class Mesh(contextlib.ContextDecorator):
 
   devices: np.ndarray
   axis_names: tuple[MeshAxisName, ...]
-  axis_types: MeshAxisType | None
+  axis_types: MeshAxisType
 
   def __new__(cls, devices: np.ndarray | Sequence[xc.Device],
               axis_names: str | Sequence[MeshAxisName], *,
@@ -199,9 +197,9 @@ def __new__(cls, devices: np.ndarray | Sequence[xc.Device],
           f"devices.ndim == {devices.ndim} and "
           f"len(axis_names) == {len(axis_names)}.")
 
-    # TODO(yashkatariya): If axis_types is None, set all axes to AUTO.
-    axis_types_tuple = (None if axis_types is None else
-                        tuple(axis_types.items()))
+    axis_types = ({AxisTypes.Auto: axis_names} if axis_types is None else
+                  axis_types)
+    axis_types_tuple = tuple(axis_types.items())
     key = (axis_names, devices.shape, tuple(devices.flat), axis_types_tuple)
     val = _mesh_object_dict.get(key, None)
     if val is not None:
@@ -337,7 +335,7 @@ def __str__(self):
   def _repr(self):
     if self.empty:
       return "Mesh(device_ids=[], axis_names=())"
-    atr = '' if self.axis_types is None else f", axis_types={self.axis_types}"
+    atr = f", axis_types={self.axis_types}"
     return f"Mesh(device_ids={self.device_ids!r}, axis_names={self.axis_names!r}{atr})"
 
   def __repr__(self):
@@ -378,14 +376,13 @@ class AbstractMesh:
   def __init__(self, shape_tuple: tuple[tuple[str, int], ...], *,
                axis_types: MeshAxisType | None = None):
     self.shape_tuple = shape_tuple
-    self.axis_types = axis_types
     if self.shape_tuple:
       self._axis_names, self._axis_sizes = list(zip(*self.shape_tuple))
     else:
       self._axis_names, self._axis_sizes = (), ()
-    # TODO(yashkatariya): If axis_types is None, set all axes to AUTO.
-    self._axis_types_tuple = (None if axis_types is None else
-                              tuple(axis_types.items()))
+    self.axis_types = ({AxisTypes.Auto: self._axis_names} if axis_types is None
+                       else axis_types)
+    self._axis_types_tuple = tuple(self.axis_types.items())
 
   def __hash__(self):
     return hash((self.shape_tuple, self._axis_types_tuple))
@@ -399,7 +396,7 @@ def __eq__(self, other):
             self._axis_types_tuple == other._axis_types_tuple)
 
   def __repr__(self):
-    atr = '' if self.axis_types is None else f", axis_types={self.axis_types}"
+    atr = f", axis_types={self.axis_types}"
     return f"AbstractMesh({self.shape_tuple}{atr})"
 
   @property
@@ -432,26 +429,18 @@ def empty(self):
 
   @functools.cached_property
   def _are_all_axes_collective(self) -> bool:
-    if self.axis_types is None:
-      return False
     return all(t == AxisTypes.Collective for t in self.axis_types.keys())
 
   @functools.cached_property
   def _are_all_axes_auto(self) -> bool:
-    if self.axis_types is None:
-      return False
     return all(t == AxisTypes.Auto for t in self.axis_types.keys())
 
   @functools.cached_property
   def _any_axis_collective(self) -> bool:
-    if self.axis_types is None:
-      return False
     return any(t == AxisTypes.Collective for t in self.axis_types.keys())
 
   @functools.cached_property
   def _any_axis_auto(self) -> bool:
-    if self.axis_types is None:
-      return False
     return any(t == AxisTypes.Auto for t in self.axis_types.keys())
 
   @property
@@ -494,8 +483,6 @@ def _raise_value_error(name):
 
 @contextlib.contextmanager
 def set_abstract_mesh(mesh: AbstractMesh):
-  if mesh is not None and mesh.axis_types is None:
-    raise RuntimeError('Please set the AxisTypes of Mesh.')
   prev_val = jax_config.abstract_mesh_context_manager.swap_local(mesh)
   try:
     yield

jax/_src/pjit.py

@@ -698,9 +698,6 @@ def get_abstract_mesh_from_avals(in_avals):
     return None
   m = None
   for a in in_avals:
-    # TODO(yashkatariya): Remove this when mesh context can be set by the user.
-    if a.sharding is None:  # type: ignore
-      continue
     if m is not None and m != a.sharding.mesh:
       raise ValueError(
           f'Mesh for all inputs should be equal. Got one mesh: {m} and'
@@ -1788,9 +1785,7 @@ def _pjit_lower(
     lowering_parameters: mlir.LoweringParameters,
     pgle_profiler: profiler.PGLEProfiler | None):
   if config.sharding_in_types.value:
-    cur_mesh = mesh_lib.get_concrete_mesh()
-    mesh = cur_mesh if isinstance(cur_mesh, mesh_lib.Mesh) else None
-    api_name = 'jit'
+    mesh, api_name = mesh_lib.get_concrete_mesh(), 'jit'
   else:
     mesh, api_name = ((resource_env.physical_mesh, 'pjit')
                       if resource_env is not None else (None, 'jit'))

tests/pjit_test.py

@@ -5483,6 +5483,24 @@ def f(x):
 
     self.assertIn('@Sharding', f.lower(arr).as_text())
 
+  @jtu.with_user_mesh((2, 2), ('x', 'y'), {mesh_lib.AxisTypes.Auto: ('x', 'y')})
+  def test_only_auto(self, mesh):
+    np_inp = np.arange(16.).reshape(8, 2)
+    arr = jax.device_put(np_inp, NamedSharding(mesh, P('x', None)))
+
+    @jax.jit
+    def f(x, x2):
+      y = x * 2
+      self.assertEqual(y.sharding.spec, P(P.UNCONSTRAINED, None))
+      z = jnp.sin(y)
+      self.assertEqual(z.sharding.spec, P(P.UNCONSTRAINED, None))
+      a = z @ x2
+      self.assertEqual(a.sharding.spec, P(P.UNCONSTRAINED, P.UNCONSTRAINED))
+      return a
+
+    out = f(arr, arr.T)
+    self.assertEqual(out.sharding, NamedSharding(mesh, P('x', None)))
+
   def test_auto_user(self):
     mesh = jtu.create_mesh((2, 2), ('x', 'y'),
                            axis_types={mesh_lib.AxisTypes.Auto: ('x', 'y')})