convert: support DT_BF16 tensors (#1309)

Co-authored-by: Pavol Rusnak <pavol@rusnak.io>
This commit is contained in:
Ivan Stepanov 2023-05-04 19:54:37 +03:00 committed by GitHub
parent 360cfe5bec
commit d3e8093e9b
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@ -67,6 +67,7 @@ FTYPE_TO_DATA_TYPE: Dict[int, DataType] = \
{ftype: dtype for (dtype, ftype) in DATA_TYPE_TO_FTYPE.items()}
DATA_TYPE_TO_NUMPY: Dict[DataType, 'np.dtype[Any]'] = {
DT_BF16: np.dtype(np.uint16),
DT_F16: np.dtype(np.float16),
DT_F32: np.dtype(np.float32),
DT_I32: np.dtype(np.int32),
@ -276,6 +277,12 @@ class Tensor(metaclass=ABCMeta):
def to_ggml(self) -> 'GGMLCompatibleTensor': ...
def bf16_to_fp32(bf16_arr: np.ndarray) -> np.ndarray:
assert bf16_arr.dtype == np.uint16, f"Input array should be of dtype uint16, but got {bf16_arr.dtype}"
fp32_arr = bf16_arr.astype(np.uint32) << 16
return fp32_arr.view(np.float32)
class UnquantizedTensor(Tensor):
def __init__(self, ndarray: NDArray) -> None:
assert isinstance(ndarray, np.ndarray)
@ -284,6 +291,8 @@ class UnquantizedTensor(Tensor):
def astype(self, data_type: DataType) -> Tensor:
dtype = DATA_TYPE_TO_NUMPY[data_type]
if self.data_type == DT_BF16:
self.ndarray = bf16_to_fp32(self.ndarray)
return UnquantizedTensor(self.ndarray.astype(dtype))
def to_ggml(self) -> 'UnquantizedTensor':
@ -686,6 +695,7 @@ class LazyUnpickler(pickle.Unpickler):
description = f'storage data_type={data_type} path-in-zip={filename} path={self.zip_file.filename}'
return LazyStorage(load=load, kind=pid[1], description=description)
@staticmethod
def lazy_rebuild_tensor_v2(storage: Any, storage_offset: Any, size: Any, stride: Any, # pyright: ignore[reportSelfClsParameterName]
requires_grad: Any, backward_hooks: Any, metadata: Any = None) -> LazyTensor:
assert isinstance(storage, LazyStorage)
@ -696,12 +706,18 @@ class LazyUnpickler(pickle.Unpickler):
description = f'pickled storage_offset={storage_offset} in {storage.description}'
return LazyTensor(load, list(size), storage.kind.data_type, description)
@staticmethod
def rebuild_from_type_v2(func, new_type, args, state):
return func(*args)
CLASSES: Dict[Any, Any] = {
('torch._tensor', '_rebuild_from_type_v2'): rebuild_from_type_v2,
('torch._utils', '_rebuild_tensor_v2'): lazy_rebuild_tensor_v2,
('torch', 'BFloat16Storage'): LazyStorageKind(DT_BF16),
('torch', 'HalfStorage'): LazyStorageKind(DT_F16),
('torch', 'FloatStorage'): LazyStorageKind(DT_F32),
('torch', 'IntStorage'): LazyStorageKind(DT_I32),
('torch', 'Tensor'): LazyTensor,
}
def find_class(self, module: str, name: str) -> Any:
@ -961,7 +977,7 @@ class OutputFile:
def pick_output_type(model: LazyModel, output_type_str: Optional[str]) -> GGMLFileType:
wq_type = model["layers.0.attention.wq.weight"].data_type
if output_type_str == "f32" or (output_type_str is None and wq_type == DT_F32):
if output_type_str == "f32" or (output_type_str is None and wq_type in (DT_F32, DT_BF16)):
return GGMLFileType.AllF32
if output_type_str == "f16" or (output_type_str is None and wq_type == DT_F16):
return GGMLFileType.MostlyF16