basic sharding support for quant tensors

sharktank/sharktank/ops/default_impls.py

@@ -438,8 +438,8 @@ def to_default(tensor: Tensor, *args, **kwargs):
     return unbox_tensor(tensor).to(*args, **kwargs)
 
 
-@transfer_to_logical_device.override(Tensor)
-def transfer_to_logical_device_default(tensor: Tensor, ordinal: int):
+@transfer_to_logical_device.override(AllOfType(AnyTensor, QuantizedTensor))
+def transfer_to_logical_device_default(tensor, ordinal: int):
     return iree.turbine.ops.iree.transfer_to_logical_device(
         f"{ordinal}", unbox_tensor(tensor)
     )

sharktank/sharktank/ops/sharded_impls.py

@@ -15,6 +15,8 @@
     AnyTensor,
     DefaultPrimitiveTensor,
     InferenceTensor,
+    QuantizedTensor,
+    PlanarQuantizedTensor,
     PrimitiveTensor,
     ReplicatedTensor,
     ShardedTensor,
@@ -28,6 +30,8 @@
 from .signatures import *
 from .shape import broadcast_dims, broadcast_dim, unbroadcast_dim
 from ..utils import longest_equal_range
+from ..utils.math import ceildiv
+from sharktank.types.tensors import REGISTERED_LAYOUT_CLASSES
 
 
 @all_gather.override(SplitPrimitiveTensor)
@@ -1264,3 +1268,82 @@ def view_split(tensor: SplitPrimitiveTensor, shape: List[int]) -> SplitPrimitive
     res = SplitPrimitiveTensor(shard_dim=shard_dim, ts=shards)
     assert math.prod(res.shape) == math.prod(tensor.shape)
     return res
+
+
+@split.override(QuantizedTensor)
+def split_QuantizedTensor(tensor: QuantizedTensor, split_size_or_sections, dim):
+    tensors = []
+    unpacked = tensor.unpack()
+    num_outputs = ceildiv(unpacked._qs.shape[dim], split_size_or_sections)
+    new_shape = unpacked._shape
+    new_shape[dim] = split_size_or_sections
+    new_qs = torch.split(unpacked._qs, split_size_or_sections, dim)
+    if unpacked._d.ndim > 0:
+        new_d = torch.split(unpacked._d, split_size_or_sections, dim)
+    if unpacked.serialized_name() == "SuperBlockOffsetScaled_4_6_Layout":
+        new_dmin = torch.split(unpacked._dmin, split_size_or_sections, dim)
+        new_sb_scales_high = torch.split(
+            unpacked._sb_scales_high, split_size_or_sections, dim
+        )
+        new_sb_scales_low = torch.split(
+            unpacked._sb_scales_low, split_size_or_sections, dim
+        )
+        new_sb_mins_high = torch.split(
+            unpacked._sb_mins_high, split_size_or_sections, dim
+        )
+        new_sb_mins_low = torch.split(
+            unpacked._sb_mins_low, split_size_or_sections, dim
+        )
+        for i in range(num_outputs):
+            layout_clazz = REGISTERED_LAYOUT_CLASSES[unpacked.serialized_name()]
+            new_layout = layout_clazz(
+                shape=new_shape,
+                d=new_d[i],
+                dmin=new_dmin[i],
+                sb_scales_high=new_sb_scales_high[i],
+                sb_scales_low=new_sb_scales_low[i],
+                sb_mins_high=new_sb_mins_high[i],
+                sb_mins_low=new_sb_mins_low[i],
+                qs=new_qs[i],
+            )
+            new_tensor = tensor.__class__
+            new_tensor_layout = new_layout.create(
+                new_layout.shape, new_layout.metadata, new_layout.planes
+            )
+            new_tensor = tensor.__class__(
+                shape=new_shape, layout=new_tensor_layout, name=tensor._name + str(i)
+            )
+            tensors.append(new_tensor)
+    else:
+        if split_size_or_sections > unpacked._qs.shape[dim]:
+            raise ValueError("split size greater than tensor dim")
+
+        if unpacked._m is not None:
+            if unpacked._m.ndim > 0:
+                new_m = torch.split(unpacked._m, split_size_or_sections, dim)
+        for i in range(num_outputs):
+            layout_clazz = REGISTERED_LAYOUT_CLASSES[unpacked.serialized_name()]
+            if unpacked._m is not None:
+                if unpacked._d.ndim > 0:
+                    new_layout = layout_clazz(
+                        shape=new_shape, d=new_d[i], qs=new_qs[i], m=new_m[i]
+                    )
+                else:
+                    new_layout = layout_clazz(
+                        shape=new_shape, d=unpacked._d, qs=new_qs[i], m=unpacked._m
+                    )
+            else:
+                if unpacked._d.ndim > 0:
+                    new_layout = layout_clazz(shape=new_shape, d=new_d[i], qs=new_qs[i])
+                else:
+                    new_layout = layout_clazz(
+                        shape=new_shape, d=unpacked._d, qs=new_qs[i]
+                    )
+            new_tensor_layout = new_layout.create(
+                new_layout.shape, new_layout.metadata, new_layout.planes
+            )
+            new_tensor = tensor.__class__(
+                shape=new_shape, layout=new_tensor_layout, name=tensor._name + str(i)
+            )
+            tensors.append(new_tensor)
+        return tensors

sharktank/sharktank/ops/signatures.py

@@ -11,7 +11,15 @@
 import torch
 import numbers
 from torch import Tensor, dtype
-from ..types import AnyTensor, ShardedTensor, Theta, sharding, InferenceTensor
+from ..types import (
+    AnyTensor,
+    ShardedTensor,
+    Theta,
+    sharding,
+    InferenceTensor,
+    QuantizedTensor,
+    PlanarQuantizedTensor,
+)
 from numbers import Number
 
 from ._registry import *
@@ -59,6 +67,7 @@
     "unshard",
     "unsqueeze",
     "view",
+    "split",
 ]
 
 IntOrSequenceInt = Union[int, Sequence[int]]
@@ -101,8 +110,9 @@ def _all_reduce_trampoline(d: SignatureDispatcher, tensor: AnyTensor):
 
 
 @overridable
-def cat(tensors: Tuple[AnyTensor, ...] | List[AnyTensor], dim: int = 0) -> AnyTensor:
-    ...
+def cat(
+    tensors: Tuple[AnyTensor, ...] | List[AnyTensor], dim: int = 0
+) -> AnyTensor: ...
 
 
 @cat.trampoline
@@ -919,8 +929,7 @@ def _sharded_cat_trampoline(d: SignatureDispatcher, maybe_sharded: AnyTensor):
 
 
 @overridable
-def sharded_sum(maybe_sharded: AnyTensor):
-    ...
+def sharded_sum(maybe_sharded: AnyTensor): ...
 
 
 @sharded_sum.trampoline
@@ -976,14 +985,18 @@ def _to_trampoline(d: SignatureDispatcher, tensor: AnyTensor, *args, **kwargs):
 
 
 @overridable
-def transfer_to_logical_device(tensor: AnyTensor, ordinal: int) -> AnyTensor:
+def transfer_to_logical_device(
+    tensor: Union[AnyTensor, QuantizedTensor, PlanarQuantizedTensor], ordinal: int
+) -> Union[AnyTensor, QuantizedTensor, PlanarQuantizedTensor]:
     """Transfer the tensor to a device with ordinal `ordinal`."""
     ...
 
 
 @transfer_to_logical_device.trampoline
 def _transfer_to_logical_device_trampoline(
-    d: SignatureDispatcher, tensor: AnyTensor, ordinal: int
+    d: SignatureDispatcher,
+    tensor: Union[AnyTensor, QuantizedTensor, PlanarQuantizedTensor],
+    ordinal: int,
 ):
     tensors = (tensor,)
     for override in d.find_overrides(tensors):
@@ -1085,3 +1098,27 @@ def _view_trampoline(
             return override, result
     else:
         d.fail(tensors)
+
+
+@overridable
+def split(
+    tensor: QuantizedTensor, split_size_or_sections: List[int], dim: int
+) -> [QuantizedTensor]:
+    """See torch.Tensor.split"""
+    ...
+
+
+@split.trampoline
+def _split_trampoline(
+    d: SignatureDispatcher,
+    tensor: QuantizedTensor,
+    split_size_or_sections: List[int],
+    dim: int,
+) -> [QuantizedTensor]:
+    tensors = (tensor,)
+    for override in d.find_overrides(tensors):
+        result = override(tensor, split_size_or_sections, dim)
+        if result is not NotImplemented:
+            return override, result
+        else:
+            d.fail(tensors)

sharktank/sharktank/types/sharding.py

@@ -60,15 +60,17 @@ def __init__(self, *args, **kwargs):
         for k, v in d.items():
             d[k] = tree.map_nodes(
                 tree=v,
-                f=lambda x: x
-                if isinstance(
-                    x,
-                    (
-                        TensorSharding,
-                        ThetaSharding,
-                    ),
-                )
-                else ThetaSharding(x),
+                f=lambda x: (
+                    x
+                    if isinstance(
+                        x,
+                        (
+                            TensorSharding,
+                            ThetaSharding,
+                        ),
+                    )
+                    else ThetaSharding(x)
+                ),
             )
         super().__init__(d)
 

sharktank/sharktank/types/tensors.py

@@ -62,8 +62,7 @@
 
 class QuantizedLayout(ABC):
     @abstractmethod
-    def dequant(self, dtype: Optional[torch.dtype] = None) -> torch.Tensor:
-        ...
+    def dequant(self, dtype: Optional[torch.dtype] = None) -> torch.Tensor: ...
 
     @classmethod
     @abstractmethod
@@ -78,8 +77,7 @@ def create(
         shape: list[int],
         metadata: Optional[dict[str, MetaDataValueType]],
         planes: dict[str, torch.Tensor],
-    ) -> "QuantizedLayout":
-        ...
+    ) -> "QuantizedLayout": ...
 
     @property
     @abstractmethod
@@ -559,8 +557,7 @@ def __init__(
         self.layout_type = layout_type
 
     @abstractmethod
-    def unpack(self) -> QuantizedLayoutT:
-        ...
+    def unpack(self) -> QuantizedLayoutT: ...
 
     def to_planar(self) -> "PlanarQuantizedTensor":
         """Converts this QuantizedTensor to a generic planar form.
@@ -581,6 +578,11 @@ def add_to_archive(self, builder: ShardedArchiveBuilder) -> InferenceTensorMetad
         """
         return self.to_planar().add_to_archive(builder)
 
+    def split(self, split_size_or_sections: [int], dim: int) -> "[QuantizedTensor]":
+        from ..ops import split
+
+        return split(self, split_size_or_sections, dim)
+
 
 @register_inference_tensor
 class PlanarQuantizedTensor(QuantizedTensor):
@@ -717,8 +719,7 @@ def __init__(
 
     @property
     @abstractmethod
-    def shard_count(self) -> int:
-        ...
+    def shard_count(self) -> int: ...
 
     @property
     @abstractmethod
@@ -941,9 +942,8 @@ def __init__(
         will be split along dimension `shard_dim` into `shard_count`
         number of pieces.
         """
-        if isinstance(ts, torch.Tensor):
+        if isinstance(ts, torch.Tensor) or isinstance(ts, InferenceTensor):
             from ..ops import transfer_to_logical_device
-
             assert shard_count is not None
             ts = ts.split(ceildiv(ts.shape[shard_dim], shard_count), dim=shard_dim)
             ts = [transfer_to_logical_device(t, i) for i, t in enumerate(ts)]

sharktank/tests/ops/ops_test.py

@@ -194,26 +194,6 @@ def testTorchImplTransposedQuantizedRHS_BlockScaledLayout(self):
             ops.custom_impls.matmul_generic_tensor_block_scaled,
         )
 
-    def testTorchImplTransposedQuantizedRHS_BlockScaledOffsetI4(self):
-        ops._registry._test_enable_last_op_dispatch(True)
-        a_dtype = torch.float32
-        d_dtype = torch.float32
-        ref_dtype = torch.float32
-        a = torch.rand([4, 16, 3200], dtype=a_dtype) / 256.0
-        d = torch.rand([3200, 100, 1], dtype=d_dtype) / 256.0
-        qs = (torch.rand([3200, 100, 16], dtype=ref_dtype) * 255.0).to(torch.uint8)
-        m = torch.rand([3200, 100, 1], dtype=d_dtype) + 16.0
-        rhs_pqt = PlanarQuantizedTensor(
-            shape=[3200, 3200],
-            layout=BlockScaledI4Layout([3200, 3200], d, qs, m=m, signed=False),
-        )
-        result = ops.matmul(a, rhs_pqt, transpose_rhs=True)
-        # Just verifying dispatch. Numerics are tested at the kernel level.
-        self.assertIs(
-            ops._registry._test_get_last_op_dispatch(),
-            ops.custom_impls.matmul_generic_tensor_block_scaled_i4,
-        )
-
     # TODO: mmt_super_block_scaled_offset_q4_unsigned