pytorch/functorch/dim/reference.py
Aaron Gokaslan 7f65a20884 [BE]: Enable ruff SLOT checks (#146276)
This enables a check that which a class which only inherits from immutable classes like str, tuple, and NamedTuple, also defined `__slots__` so they don't allocate memory unnecessarily. This also ensure contributors think about how they define their classes with subclass NamedTuples and str, of which we have many in our codebase

Pull Request resolved: https://github.com/pytorch/pytorch/pull/146276
Approved by: https://github.com/aorenste
2025-02-04 19:18:23 +00:00

646 lines
20 KiB
Python

# Copyright (c) Facebook, Inc. and its affiliates.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.
# reference python implementations for C ops
import torch
from functorch._C import dim as _C
from . import op_properties
from .batch_tensor import _enable_layers
from .tree_map import tree_flatten, tree_map
DimList = _C.DimList
import operator
from functools import reduce
# use dict to avoid writing C++ bindings for set
pointwise = set(op_properties.pointwise)
def prod(x):
return reduce(operator.mul, x, 1)
def _wrap_dim(d, N, keepdim):
from . import Dim
if isinstance(d, Dim):
assert not keepdim, "cannot preserve first-class dimensions with keepdim=True"
return d
elif d >= 0:
return d - N
else:
return d
def _dims(d, N, keepdim, single_dim):
from . import Dim
if isinstance(d, (Dim, int)):
return ltuple((_wrap_dim(d, N, keepdim),))
assert not single_dim, f"expected a single dimension or int but found: {d}"
return ltuple(_wrap_dim(x, N, keepdim) for x in d)
def _bind_dims_to_size(lhs_size, rhs, lhs_debug):
from . import DimensionMismatchError
not_bound = tuple((i, r) for i, r in enumerate(rhs) if not r.is_bound)
if len(not_bound) == 1:
idx, d = not_bound[0]
rhs_so_far = prod(r.size for r in rhs if r.is_bound)
if lhs_size % rhs_so_far != 0:
rhs_s = tuple("?" if not r.is_bound else str(r.size) for r in rhs)
raise DimensionMismatchError(
f"inferred dimension does not evenly fit into larger dimension: {lhs_size} vs {rhs_s}"
)
new_size = lhs_size // rhs_so_far
d.size = new_size
elif len(not_bound) > 1:
rhs_s = tuple("?" if not r.is_bound else str(r.size) for r in rhs)
raise DimensionMismatchError(
f"cannot infer the size of two dimensions at once: {rhs} with sizes {rhs_s}"
)
else:
rhs_size = prod(r.size for r in rhs)
if lhs_size != rhs_size:
raise DimensionMismatchError(
f"Dimension sizes to do not match ({lhs_size} != {rhs_size}) when matching {lhs_debug} to {rhs}"
)
def _tensor_levels(inp):
from . import _Tensor
if isinstance(inp, _Tensor):
return inp._tensor, llist(inp._levels), inp._has_device
else:
return inp, llist(range(-inp.ndim, 0)), True
def _match_levels(v, from_levels, to_levels):
view = []
permute = []
requires_view = False
size = v.size()
for t in to_levels:
try:
idx = from_levels.index(t)
permute.append(idx)
view.append(size[idx])
except ValueError:
view.append(1)
requires_view = True
if permute != list(range(len(permute))):
v = v.permute(*permute)
if requires_view:
v = v.view(*view)
return v
# make a single dimension positional but do not permute it,
# used to do multi-tensor operators where the dim being acted on
# should not physically move if possible
def _positional_no_permute(self, dim, expand_dim=False):
from . import Tensor
ptensor, levels = self._tensor, llist(self._levels)
try:
idx = levels.index(dim)
except ValueError:
if not expand_dim:
raise
idx = 0
ptensor = ptensor.expand(dim.size, *ptensor.size())
levels.insert(0, 0)
idx_batched = 0
for i in range(idx):
if isinstance(levels[i], int):
levels[i] -= 1
idx_batched += 1
levels[idx] = -idx_batched - 1
return Tensor.from_positional(ptensor, levels, self._has_device), idx_batched
def seq(a, b):
from . import Dim
if isinstance(a, Dim) != isinstance(b, Dim):
return False
if isinstance(a, Dim):
return a is b
else:
return a == b
class isin:
__slots__ = ()
def __contains__(self, item):
for x in self:
if seq(item, x):
return True
return False
def index(self, item):
for i, x in enumerate(self):
if seq(item, x):
return i
raise ValueError
class llist(isin, list):
__slots__ = ()
class ltuple(isin, tuple):
__slots__ = ()
empty_dict = {}
@classmethod
def __torch_function__(self, orig, cls, args, kwargs=empty_dict):
from . import _Tensor, Tensor, TensorLike
from .delayed_mul_tensor import DelayedMulTensor
if orig is torch.Tensor.__mul__:
lhs, rhs = args
if (
isinstance(lhs, _Tensor)
and isinstance(rhs, _Tensor)
and lhs.ndim == 0
and rhs.ndim == 0
):
return DelayedMulTensor(lhs, rhs)
all_dims = llist()
flat_args, unflatten = tree_flatten((args, kwargs))
device_holding_tensor = None
for f in flat_args:
if isinstance(f, _Tensor):
if f._has_device:
device_holding_tensor = f._batchtensor
for d in f.dims:
if d not in all_dims:
all_dims.append(d)
def unwrap(t):
if isinstance(t, _Tensor):
r = t._batchtensor
if device_holding_tensor is not None and not t._has_device:
r = r.to(device=device_holding_tensor.device)
return r
return t
if orig in pointwise:
result_levels = llist()
to_expand = []
for i, f in enumerate(flat_args):
if isinstance(f, TensorLike):
ptensor, levels, _ = _tensor_levels(f)
if (
isinstance(f, _Tensor)
and not f._has_device
and device_holding_tensor is not None
):
ptensor = ptensor.to(device=device_holding_tensor.device)
flat_args[i] = ptensor
for l in levels:
if l not in result_levels:
result_levels.append(l)
to_expand.append((i, levels))
for i, levels in to_expand:
flat_args[i] = _match_levels(flat_args[i], levels, result_levels)
args, kwargs = unflatten(flat_args)
result = orig(*args, **kwargs)
def wrap(t):
if isinstance(t, TensorLike):
return Tensor.from_positional(
t, result_levels, device_holding_tensor is not None
)
return t
return tree_map(wrap, result)
else:
def wrap(t):
if isinstance(t, TensorLike):
return Tensor.from_batched(t, device_holding_tensor is not None)
return t
with _enable_layers(all_dims):
print(f"batch_tensor for {orig}")
args, kwargs = unflatten(unwrap(f) for f in flat_args)
result = orig(*args, **kwargs)
# print("END", orig)
return tree_map(wrap, result)
def positional(self, *dims):
from . import Dim, DimensionBindError, Tensor
ptensor, levels = self._tensor, llist(self._levels)
flat_dims = llist()
view = []
needs_view = False
ndim = self.ndim
for d in dims:
if isinstance(d, DimList):
flat_dims.extend(d)
view.extend(e.size for e in d)
elif isinstance(d, Dim):
flat_dims.append(d)
view.append(d.size)
elif isinstance(d, int):
d = _wrap_dim(d, ndim, False)
flat_dims.append(d)
view.append(ptensor.size(d))
else:
flat_dims.extend(d)
view.append(prod(e.size for e in d))
needs_view = True
permute = list(range(len(levels)))
for i, d in enumerate(flat_dims):
try:
idx = levels.index(d)
except ValueError as e:
raise DimensionBindError(
f"tensor of dimensions {self.dims} does not contain dim {d}"
) from e
p = permute[idx]
del levels[idx]
del permute[idx]
levels.insert(i, 0)
permute.insert(i, p)
ptensor = ptensor.permute(*permute)
seen = 0
for i in range(len(levels) - 1, -1, -1):
if isinstance(levels[i], int):
seen += 1
levels[i] = -seen
result = Tensor.from_positional(ptensor, levels, self._has_device)
if needs_view:
result = result.reshape(*view, *result.size()[len(flat_dims) :])
return result
def _contains_dim(input):
from . import Dim
for i in input:
if isinstance(i, Dim):
return True
def expand(self, *sizes):
if not _contains_dim(sizes):
return self.__torch_function__(torch.Tensor.expand, None, (self, *sizes))
dims = sizes
sizes = [d.size for d in dims] + [-1] * self.ndim
self = self.expand(*sizes)
return self[dims]
_not_present = object()
def _getarg(name, offset, args, kwargs, default):
if len(args) > offset:
return args[offset]
return kwargs.get(name, default)
def _patcharg(name, offset, args, kwargs, value):
if len(args) > offset:
args[offset] = value
else:
kwargs[name] = value
def _wrap(
orig, dim_offset=0, keepdim_offset=1, dim_name="dim", single_dim=False, reduce=True
):
from . import Dim, Tensor, TensorLike
def fn(self, *args, **kwargs):
dim = _getarg(dim_name, dim_offset, args, kwargs, _not_present)
if dim is _not_present or (single_dim and not isinstance(dim, Dim)):
with _enable_layers(self.dims):
print(f"dim fallback batch_tensor for {orig}")
return Tensor.from_batched(
orig(self._batchtensor, *args, **kwargs), self._has_device
)
keepdim = (
_getarg("keepdim", keepdim_offset, args, kwargs, False) if reduce else False
)
t, levels = self._tensor, llist(self._levels)
dims = _dims(dim, self._batchtensor.ndim, keepdim, single_dim)
dim_indices = tuple(levels.index(d) for d in dims)
if reduce and not keepdim:
new_levels = [l for i, l in enumerate(levels) if i not in dim_indices]
else:
new_levels = levels
if len(dim_indices) == 1:
dim_indices = dim_indices[
0
] # so that dims that really only take a single argument work...
args = list(args)
_patcharg(dim_name, dim_offset, args, kwargs, dim_indices)
def wrap(t):
if isinstance(t, TensorLike):
return Tensor.from_positional(t, new_levels, self._has_device)
return t
with _enable_layers(new_levels):
print(f"dim used batch_tensor for {orig}")
r = orig(t, *args, **kwargs)
return tree_map(wrap, r)
return fn
def _def(name, *args, **kwargs):
from . import _Tensor
orig = getattr(torch.Tensor, name)
setattr(_Tensor, name, _wrap(orig, *args, **kwargs))
no_slice = slice(None)
_orig_getitem = torch.Tensor.__getitem__
class dim_tracker:
def __init__(self) -> None:
self.dims = llist()
self.count = []
def record(self, d):
if d not in self.dims:
self.dims.append(d)
self.count.append(1)
def __getitem__(self, d):
return self.count[self.dims.index(d)]
def t__getitem__(self, input):
from . import _Tensor, Dim, DimensionBindError, DimList, Tensor, TensorLike
# * bail to original example if we have a single non-Dim tensor, or a non-tensor
# * locate ... or an unbound tensor list, and determine its size, bind dim list
# (remember that None does not count to the total dim count)
# * bind simple dims and dim-packs to their sizes, count the number of uses of each dim,
# produce the re-view if needed
# * for each single-use dim index, replace with no_slice and mark that it will be added
# (keep track of whether we have to call super)
# * call super if needed
# * if we have dims to bind, bind them (it will help if we eliminated ... and None before)
# this handles bool indexing handling, as well as some other simple cases.
is_simple = (
not isinstance(input, Dim)
and not isinstance(input, (tuple, list))
and
# WAR for functorch bug where zero time tensors in getitem are not handled correctly.
not (isinstance(input, TensorLike) and input.ndim == 0)
)
if is_simple:
if isinstance(self, _Tensor):
return _Tensor.__torch_function__(_orig_getitem, None, (self, input))
else:
return _orig_getitem(self, input)
# can further optimize this case
if not isinstance(input, tuple):
input = [input]
else:
input = list(input)
dims_indexed = 0
expanding_object = None
dimlists = []
for i, s in enumerate(input):
if s is ... or isinstance(s, DimList) and not s.is_bound:
if expanding_object is not None:
msg = (
"at most one ... or unbound dimension list can exist in indexing list but"
f" found 2 at offsets {i} and {expanding_object}"
)
raise DimensionBindError(msg)
expanding_object = i
if isinstance(s, DimList):
dims_indexed += len(s) if s.is_bound else 0
dimlists.append(i)
elif s is not None and s is not ...:
dims_indexed += 1
ndim = self.ndim
if dims_indexed > ndim:
raise IndexError(
f"at least {dims_indexed} indices were supplied but the tensor only has {ndim} dimensions."
)
if expanding_object is not None:
expanding_ndims = ndim - dims_indexed
obj = input[expanding_object]
if obj is ...:
input[expanding_object : expanding_object + 1] = [
no_slice
] * expanding_ndims
else:
obj.bind_len(expanding_ndims)
# flatten the dimslists into the indexing
for i in reversed(dimlists):
input[i : i + 1] = input[i]
dims_indexed = 0
requires_view = False
size = self.size()
view_sizes = []
dims_seen = dim_tracker()
def add_dims(t):
if not isinstance(t, _Tensor):
return
for d in t.dims:
dims_seen.record(d)
add_dims(self)
dim_packs = []
for i, idx in enumerate(input):
if idx is None:
input[i] = no_slice
view_sizes.append(1)
requires_view = True
else:
sz = size[dims_indexed]
if isinstance(idx, Dim):
idx.size = sz
dims_seen.record(idx)
view_sizes.append(sz)
elif isinstance(idx, (tuple, list)) and idx and isinstance(idx[0], Dim):
for d in idx:
dims_seen.record(idx)
_bind_dims_to_size(sz, idx, f"offset {i}")
view_sizes.extend(d.size for d in idx)
requires_view = True
dim_packs.append(i)
else:
add_dims(idx)
view_sizes.append(sz)
dims_indexed += 1
if requires_view:
self = self.view(*view_sizes)
for i in reversed(dim_packs):
input[i : i + 1] = input[i]
# currenty:
# input is flat, containing either Dim, or Tensor, or something valid for standard indexing
# self may have first-class dims as well.
# to index:
# drop the first class dims from self, they just become direct indices of their positions
# figure out the dimensions of the indexing tensors: union of all the dims in the tensors in the index.
# these dimensions will appear and need to be bound at the first place tensor occures
if isinstance(self, _Tensor):
ptensor_self, levels = self._tensor, list(self._levels)
# indices to ptensor rather than self which has first-class dimensions
input_it = iter(input)
flat_inputs = [next(input_it) if isinstance(l, int) else l for l in levels]
has_device = self._has_device
to_pad = 0
else:
ptensor_self, flat_inputs = self, input
to_pad = ptensor_self.ndim - len(flat_inputs)
has_device = True
result_levels = []
index_levels = []
tensor_insert_point = None
to_expand = {}
requires_getindex = False
for i, inp in enumerate(flat_inputs):
if isinstance(inp, Dim) and dims_seen[inp] == 1:
flat_inputs[i] = no_slice
result_levels.append(inp)
elif isinstance(inp, TensorLike):
requires_getindex = True
if tensor_insert_point is None:
tensor_insert_point = len(result_levels)
ptensor, levels, _ = _tensor_levels(inp)
to_expand[i] = levels
flat_inputs[i] = ptensor
for l in levels:
if l not in index_levels:
index_levels.append(l)
else:
requires_getindex = True
result_levels.append(0)
if tensor_insert_point is not None:
result_levels[tensor_insert_point:tensor_insert_point] = index_levels
for i, levels in to_expand.items():
flat_inputs[i] = _match_levels(flat_inputs[i], levels, index_levels)
if requires_getindex:
result = _orig_getitem(ptensor_self, flat_inputs)
else:
result = ptensor_self
next_positional = -1
if to_pad > 0:
result_levels.extend([0] * to_pad)
for i, r in enumerate(reversed(result_levels)):
if isinstance(r, int):
result_levels[-1 - i] = next_positional
next_positional -= 1
return Tensor.from_positional(result, result_levels, has_device)
# XXX - dim is optional and can be the outer-most dimension...
def stack(tensors, new_dim, dim=0, out=None):
if isinstance(dim, int):
return torch.stack(tensors, dim, out).index(dim, new_dim)
index = None
if out is not None:
out, index = _positional_no_permute(out, dim, expand_dim=True)
ptensors = []
for t in tensors:
pt, pi = _positional_no_permute(t, dim, expand_dim=True)
if index is not None and pi != index:
pt = pt.move_dim(pi, index)
else:
index = pi
ptensors.append(pt)
pr = torch.stack(ptensors, index, out=out)
return pr.index((index, index + 1), (new_dim, dim))
_orig_split = torch.Tensor.split
def split(self, split_size_or_sections, dim=0):
from . import _Tensor, Dim
if isinstance(split_size_or_sections, int) or any(
isinstance(t, int) for t in split_size_or_sections
):
if isinstance(dim, Dim):
raise ValueError(
"when dim is specified as a Dim object, split sizes must also be dimensions."
)
return _orig_split(self, split_size_or_sections, dim=dim)
if isinstance(dim, Dim):
assert isinstance(self, _Tensor), f"Tensor does not have dimension {dim}"
self, dim = _positional_no_permute(self, dim)
size = self.size(dim)
total_bound_size = 0
unbound = []
sizes = []
for i, d in enumerate(split_size_or_sections):
if d.is_bound:
sizes.append(d.size)
total_bound_size += d.size
else:
sizes.append(0)
unbound.append(i)
if unbound:
assert (
total_bound_size <= size
), f"result dimensions are larger than original: {total_bound_size} vs {size} ({split_size_or_sections})"
remaining_size = size - total_bound_size
chunk_size = -(-remaining_size // len(unbound))
for u in unbound:
sz = min(chunk_size, remaining_size)
split_size_or_sections[u].size = sz
sizes[u] = sz
remaining_size -= sz
else:
assert (
total_bound_size == size
), f"result dimensions do not match original: {total_bound_size} vs {size} ({split_size_or_sections})"
return tuple(
t.index(dim, d)
for d, t in zip(split_size_or_sections, _orig_split(self, sizes, dim=dim))
)