New embedding quant fusion

Differential Revision: D73381542

Pull Request resolved: #10325

Author: metascroy

exir/TARGETS

@@ -16,6 +16,7 @@ python_library(
         "//caffe2:torch",
         "//executorch/exir/operator:convert",
         "//executorch/extension/pytree:pylib",
+        "//pytorch/ao:torchao",
     ],
 )
 

exir/passes/_quant_patterns_and_replacements.py

@@ -22,6 +22,56 @@
     "get_quant_patterns_and_replacements",
 ]
 
+
+from torch import Tensor
+from torch.library import custom_op
+
+
+@custom_op("quant_fusion::_pack_embedding_weight", mutates_args=())
+def _pack_embedding_weight(weight: Tensor, bitwidth: int) -> Tensor:
+    num_embeddings, embedding_dim = weight.shape
+
+    if bitwidth == 2:
+        assert embedding_dim % 4 == 0, "embedding_dim must be divisible by 4"
+        weight_range_shifted = weight.add(2).view(torch.uint8)
+        weight_view = weight_range_shifted.view(num_embeddings, embedding_dim // 4, 4)
+        weight_0 = weight_view[:, :, 0]
+        weight_1 = weight_view[:, :, 1] << 2
+        weight_2 = weight_view[:, :, 2] << 4
+        weight_3 = weight_view[:, :, 3] << 6
+        packed_weight = weight_0 | weight_1 | weight_2 | weight_3
+        return packed_weight
+    elif bitwidth == 4:
+        assert embedding_dim % 2 == 0, "embedding_dim must be divisible by 2"
+        weight_range_shifted = weight.add(8).view(torch.uint8)
+        weight_view = weight_range_shifted.view(
+            weight.shape[0], weight.shape[1] // 2, 2
+        )
+        weight_even = weight_view[:, :, 0] << 4
+        weight_odd = weight_view[:, :, 1]
+        packed_weight = weight_even | weight_odd
+        return packed_weight
+    elif bitwidth == 8:
+        return weight
+
+    raise RuntimeError(f"Unsupported bitwidth {bitwidth}")
+
+
+# Use register_fake to add a ``FakeTensor`` kernel for the operator
+@_pack_embedding_weight.register_fake
+def _(weight, bit_width):
+    assert bit_width in [2, 4, 8]
+    num_embeddings, embedding_dim = weight.shape
+    values_per_byte = 8 // bit_width
+    assert embedding_dim % values_per_byte == 0
+    return torch.empty(
+        num_embeddings,
+        embedding_dim // values_per_byte,
+        dtype=torch.uint8,
+        device=weight.device,
+    )
+
+
 # TODO: extending an existing library that is defined in OSS might be a bit
 # confusing, we can investigate if it is possible to define a new library
 
@@ -69,9 +119,10 @@ def embedding_weight_checks(weight, weight_scales, weight_zero_points):
     assert (
         weight_zero_points is None or weight_zero_points.dtype == weight_scales.dtype
     ), "Expecting weight_zero_points to be None or have same dtype as weight_scales"
-    assert (
-        weight_zero_points is None or weight_zero_points.dim() == 1
-    ), f"Expecting weight_zero_points tensor to be None or have dim()==1, but found {weight_zero_points.dim()}"
+    assert weight_zero_points is None or weight_zero_points.dim() in [
+        1,
+        2,
+    ], f"Expecting weight_zero_points tensor to be None or have dim()==1, but found {weight_zero_points.dim()}"
     assert weight_zero_points is None or weight_zero_points.size(0) == weight.size(
         0
     ), f"Expecting weight_zero_points tensor to be None or have same number of rows as weights, but found {weight.size()} and {weight_zero_points.size()}"
@@ -234,6 +285,21 @@ def embedding_2bit(
     return torch.ops.aten.embedding.default(weight, indices)
 
 
+@register_fake("quantized_decomposed::embedding_2bit")
+def _(
+    weight: torch.Tensor,
+    weight_scales: torch.Tensor,
+    weight_zero_points: Optional[torch.Tensor],
+    weight_quant_min: int,
+    weight_quant_max: int,
+    indices: torch.Tensor,
+):
+    num_embeddings, packed_embedding_dim = weight.shape
+    embedding_dim = packed_embedding_dim * 4
+    embedding = torch.nn.Embedding(num_embeddings, embedding_dim, device=weight.device)
+    return embedding(indices)
+
+
 @register_fake("quantized_decomposed::embedding_2bit.out")
 def embedding_2bit_out_meta(
     weight: torch.Tensor,
@@ -296,6 +362,22 @@ def embedding_2bit_dtype(
     return torch.ops.aten.embedding.default(weight, indices)
 
 
+@register_fake("quantized_decomposed::embedding_2bit.dtype")
+def _(
+    weight: torch.Tensor,
+    weight_scales: torch.Tensor,
+    weight_zero_points: Optional[torch.Tensor],
+    weight_quant_min: int,
+    weight_quant_max: int,
+    indices: torch.Tensor,
+    dtype: Optional[torch.dtype],
+) -> torch.Tensor:
+    num_embeddings, packed_embedding_dim = weight.shape
+    embedding_dim = packed_embedding_dim * 4
+    embedding = torch.nn.Embedding(num_embeddings, embedding_dim, device=weight.device)
+    return embedding(indices).to(dtype)
+
+
 @register_fake("quantized_decomposed::embedding_2bit.dtype_out")
 def embedding_2bit_dtype_out_meta(
     weight: torch.Tensor,
@@ -378,6 +460,21 @@ def embedding_4bit(
     return torch.ops.aten.embedding.default(weight, indices)
 
 
+@register_fake("quantized_decomposed::embedding_4bit")
+def _(
+    weight: torch.Tensor,
+    weight_scales: torch.Tensor,
+    weight_zero_points: Optional[torch.Tensor],
+    weight_quant_min: int,
+    weight_quant_max: int,
+    indices: torch.Tensor,
+):
+    num_embeddings, packed_embedding_dim = weight.shape
+    embedding_dim = packed_embedding_dim * 2
+    embedding = torch.nn.Embedding(num_embeddings, embedding_dim, device=weight.device)
+    return embedding(indices)
+
+
 @register_fake("quantized_decomposed::embedding_4bit.out")
 def embedding_4bit_out_meta(
     weight: torch.Tensor,
@@ -438,6 +535,22 @@ def embedding_4bit_dtype(
     return torch.ops.aten.embedding.default(weight, indices)
 
 
+@register_fake("quantized_decomposed::embedding_4bit.dtype")
+def _(
+    weight: torch.Tensor,
+    weight_scales: torch.Tensor,
+    weight_zero_points: Optional[torch.Tensor],
+    weight_quant_min: int,
+    weight_quant_max: int,
+    indices: torch.Tensor,
+    dtype: Optional[torch.dtype],
+) -> torch.Tensor:
+    num_embeddings, packed_embedding_dim = weight.shape
+    embedding_dim = packed_embedding_dim * 2
+    embedding = torch.nn.Embedding(num_embeddings, embedding_dim, device=weight.device)
+    return embedding(indices).to(dtype)
+
+
 @register_fake("quantized_decomposed::embedding_4bit.dtype_out")
 def embedding_4bit_dtype_out_meta(
     weight: torch.Tensor,
@@ -873,6 +986,186 @@ def replacement(x, dim, start, end, x_scale, x_zero_point, x_qmin, x_qmax):
     ]
 
 
+def _get_embedding_ops_patterns_and_replacements_torchao() -> (  # noqa C901
+    List[Tuple[Callable, Callable, List[Callable]]]
+):
+    def embedding_byte_pattern(indices, int_data, group_size, scale, zero_point):
+        dq = torch.ops.torchao.dequantize_affine.default(
+            int_data, [1, group_size], scale, zero_point, torch.int8, -128, 127
+        )
+        return torch.ops.aten.embedding.default(dq, indices)
+
+    def embedding_byte_replacement(indices, int_data, group_size, scale, zero_point):
+        zero_point_dtype_cast = torch.ops.aten.to.dtype(zero_point, scale.dtype)
+        return torch.ops.quantized_decomposed.embedding_byte.default(
+            int_data,
+            scale,
+            zero_point_dtype_cast,
+            -128,
+            127,
+            indices,
+        )
+
+    def embedding_byte_dtype_pattern(
+        indices, int_data, group_size, scale, zero_point, output_dtype
+    ):
+        dq = torch.ops.torchao.dequantize_affine.default(
+            int_data,
+            [1, group_size],
+            scale,
+            zero_point,
+            torch.int8,
+            -128,
+            127,
+            "INT",
+            output_dtype,
+        )
+        return torch.ops.aten.embedding.default(dq, indices)
+
+    def embedding_byte_dtype_replacement(
+        indices, int_data, group_size, scale, zero_point, output_dtype
+    ):
+        zero_point_dtype_cast = torch.ops.aten.to.dtype(zero_point, scale.dtype)
+        return torch.ops.quantized_decomposed.embedding_byte.dtype(
+            int_data,
+            scale,
+            zero_point_dtype_cast,
+            -128,
+            127,
+            indices,
+            dtype=output_dtype,
+        )
+
+    def embedding_2bit_pattern(indices, int_data, group_size, scale, zero_point):
+        dq = torch.ops.torchao.dequantize_affine.default(
+            int_data, [1, group_size], scale, zero_point, torch.int8, -2, 1
+        )
+        return torch.ops.aten.embedding.default(dq, indices)
+
+    def embedding_2bit_replacement(indices, int_data, group_size, scale, zero_point):
+        packed_int_data = torch.ops.quant_fusion._pack_embedding_weight.default(
+            int_data, 2
+        )
+        zero_point_dtype_cast = torch.ops.aten.to.dtype(zero_point, scale.dtype)
+        return torch.ops.quantized_decomposed.embedding_2bit.default(
+            packed_int_data, scale, zero_point_dtype_cast, -2, 1, indices
+        )
+
+    def embedding_2bit_dtype_pattern(
+        indices, int_data, group_size, scale, zero_point, output_dtype
+    ):
+        dq = torch.ops.torchao.dequantize_affine.default(
+            int_data,
+            [1, group_size],
+            scale,
+            zero_point,
+            torch.int8,
+            -2,
+            1,
+            "INT",
+            output_dtype,
+        )
+        return torch.ops.aten.embedding.default(dq, indices)
+
+    def embedding_2bit_dtype_replacement(
+        indices, int_data, group_size, scale, zero_point, output_dtype
+    ):
+        packed_int_data = torch.ops.quant_fusion._pack_embedding_weight.default(
+            int_data, 2
+        )
+        zero_point_dtype_cast = torch.ops.aten.to.dtype(zero_point, scale.dtype)
+        return torch.ops.quantized_decomposed.embedding_2bit.dtype(
+            packed_int_data,
+            scale,
+            zero_point_dtype_cast,
+            -2,
+            1,
+            indices,
+            dtype=output_dtype,
+        )
+
+    def embedding_4bit_pattern(indices, int_data, group_size, scale, zero_point):
+        dq = torch.ops.torchao.dequantize_affine.default(
+            int_data, [1, group_size], scale, zero_point, torch.int8, -8, 7
+        )
+        return torch.ops.aten.embedding.default(dq, indices)
+
+    def embedding_4bit_replacement(indices, int_data, group_size, scale, zero_point):
+        packed_int_data = torch.ops.quant_fusion._pack_embedding_weight.default(
+            int_data, 4
+        )
+        zero_point_dtype_cast = torch.ops.aten.to.dtype(zero_point, scale.dtype)
+        return torch.ops.quantized_decomposed.embedding_4bit.default(
+            packed_int_data, scale, zero_point_dtype_cast, -8, 7, indices
+        )
+
+    def embedding_4bit_dtype_pattern(
+        indices, int_data, group_size, scale, zero_point, output_dtype
+    ):
+        dq = torch.ops.torchao.dequantize_affine.default(
+            int_data,
+            [1, group_size],
+            scale,
+            zero_point,
+            torch.int8,
+            -8,
+            7,
+            "INT",
+            output_dtype,
+        )
+        return torch.ops.aten.embedding.default(dq, indices)
+
+    def embedding_4bit_dtype_replacement(
+        indices, int_data, group_size, scale, zero_point, output_dtype
+    ):
+        packed_int_data = torch.ops.quant_fusion._pack_embedding_weight.default(
+            int_data, 4
+        )
+        zero_point_dtype_cast = torch.ops.aten.to.dtype(zero_point, scale.dtype)
+        return torch.ops.quantized_decomposed.embedding_4bit.dtype(
+            packed_int_data,
+            scale,
+            zero_point_dtype_cast,
+            -8,
+            7,
+            indices,
+            dtype=output_dtype,
+        )
+
+    return [
+        (
+            _trace_and_lower_to_edge_ops(embedding_byte_pattern),
+            _trace_and_lower_to_edge_ops(embedding_byte_replacement),
+            [],
+        ),
+        (
+            _trace_and_lower_to_edge_ops(embedding_byte_dtype_pattern),
+            _trace_and_lower_to_edge_ops(embedding_byte_dtype_replacement),
+            [],
+        ),
+        (
+            _trace_and_lower_to_edge_ops(embedding_2bit_pattern),
+            _trace_and_lower_to_edge_ops(embedding_2bit_replacement),
+            [],
+        ),
+        (
+            _trace_and_lower_to_edge_ops(embedding_2bit_dtype_pattern),
+            _trace_and_lower_to_edge_ops(embedding_2bit_dtype_replacement),
+            [],
+        ),
+        (
+            _trace_and_lower_to_edge_ops(embedding_4bit_pattern),
+            _trace_and_lower_to_edge_ops(embedding_4bit_replacement),
+            [],
+        ),
+        (
+            _trace_and_lower_to_edge_ops(embedding_4bit_dtype_pattern),
+            _trace_and_lower_to_edge_ops(embedding_4bit_dtype_replacement),
+            [],
+        ),
+    ]
+
+
 def _get_embedding_ops_patterns_and_replacements() -> (
     List[Tuple[Callable, Callable, List[Callable]]]
 ):
@@ -1167,5 +1460,6 @@ def get_quant_patterns_and_replacements() -> (
             *_get_slice_patterns_and_replacements(),
             # *_get_fixed_qparams_ops_patterns_and_replacements(),
             *_get_embedding_ops_patterns_and_replacements(),
+            *_get_embedding_ops_patterns_and_replacements_torchao(),
         ]
     )

exir/passes/quant_fusion_pass.py

@@ -90,6 +90,18 @@ def _get_qparams(node):
         model.graph.erase_node(qnode)
 
 
+def _remove_dtype_getattr_nodes(model: GraphModule) -> None:
+    for n in model.graph.nodes:
+        if n.op == "call_function" and n.target == getattr:
+            if isinstance(n.args[0], torch.fx.Node) and n.args[1] == "dtype":
+                dtype = n.args[0].meta["val"].dtype
+                n.replace_all_uses_with(dtype)
+                model.graph.erase_node(n)
+    model.graph.eliminate_dead_code()
+    model.graph.lint()
+    model.recompile()
+
+
 class QuantFusionPass(ExportPass):
     def __init__(self, _fix_node_meta_val=False):
         super().__init__()
@@ -123,6 +135,7 @@ def call(self, graph_module: GraphModule) -> PassResult:
                         torch.fx.Node, lambda x: x.meta["val"], (n.args, n.kwargs)
                     )
                     n.meta["val"] = n.target(*args, **kwargs)
+        _remove_dtype_getattr_nodes(graph_module)
         graph_module.graph.lint()
         graph_module.graph.eliminate_dead_code()
         return PassResult(graph_module, True)

exir/tests/TARGETS

@@ -298,6 +298,8 @@ python_unittest(
         "//caffe2:torch",
         "//executorch/exir:lib",
         "//executorch/exir/passes:quant_fusion_pass",
+        "//pytorch/ao:torchao",
+        "//executorch/exir/passes:constant_prop_pass",
     ],
 )