pytorch/torch/_meta_registrations.py
lezcano dc7066a8f0 Add support for multiple inputs to out_wrapper and strict dtype checking (#79941)
When a function returns multiple parameters in PyTorch, the `out`
parameter takes a tuple of tensors (see `linalg.svd` for example).
The current implementation in `out_wrapper_multi` modelled this wrong,
as it assumed that it would take a number of different named
parameters.

This PR implements the correct behaviour in `out_wrapper`. As a small
side-effect, we now need to call `@out_wrapper()` when the output is
just one tensor.

This PR also implements an additional optional parameter that checks
whether the dtype of the given `out` is exactly the dtype that the meta
function requires. This is the behaviour that we currently have in
PyTorch, and this check is necessary in eager when we call with these
tensors into external libraries.

We also make the functions with several outputs return a namedtuple,
similar to what we do in PyTorch.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/79941
Approved by: https://github.com/mruberry, https://github.com/ezyang
2022-06-30 02:47:16 +00:00

571 lines
19 KiB
Python

import torch
from torch import Tensor
from torch._prims import utils
from torch._prims.utils import (
ELEMENTWISE_TYPE_PROMOTION_KIND,
check,
elementwise_dtypes,
)
from torch._prims.wrappers import out_wrapper
from typing import List, Optional
meta_lib = torch.library.Library("aten", "IMPL", "Meta")
def toRealValueType(dtype):
from_complex = {
torch.complex32: torch.half,
torch.cfloat: torch.float,
torch.cdouble: torch.double,
}
return from_complex.get(dtype, dtype)
@torch.library.impl(meta_lib, "_fft_c2c")
def meta_fft_c2c(self, dim, normalization, forward):
assert self.dtype.is_complex
return self.new_empty(self.size())
@torch.library.impl(meta_lib, "_fft_r2c")
def meta_fft_r2c(self, dim, normalization, onesided):
assert self.dtype.is_floating_point
output_sizes = list(self.size())
if onesided:
last_dim = dim[-1]
last_dim_halfsize = (output_sizes[last_dim] // 2) + 1
output_sizes[last_dim] = last_dim_halfsize
return self.new_empty(
output_sizes, dtype=utils.corresponding_complex_dtype(self.dtype)
)
@torch.library.impl(meta_lib, "_fft_c2r.out")
@torch.library.impl(meta_lib, "_fft_c2r")
@out_wrapper()
def meta_fft_c2r(self, dim, normalization, lastdim):
assert self.dtype.is_complex
output_sizes = list(self.size())
output_sizes[dim[-1]] = lastdim
return self.new_empty(output_sizes, dtype=toRealValueType(self.dtype))
@torch.library.impl(meta_lib, "conj_physical.out")
def meta_conj_physical_out(self, out):
return torch._resize_output_(out, self.size(), self.device)
# Implementations below are taken from https://github.com/albanD/subclass_zoo/blob/main/python_meta_tensor.py
@torch.library.impl(meta_lib, "index_select")
def meta_index_select(self, dim, index):
result_size = list(self.size())
if self.dim() > 0:
result_size[dim] = index.numel()
return self.new_empty(result_size)
@torch.library.impl(meta_lib, "index_select.out")
def meta_index_select_out(self, dim, index, out):
torch._resize_output_(out, self.size(), self.device)
return out.copy_(torch.index_select(self, dim, index))
@torch.library.impl(meta_lib, "max")
def meta_max(self):
return self.new_empty(())
@torch.library.impl(meta_lib, "min")
def meta_min(self):
return self.new_empty(())
@torch.library.impl(meta_lib, "angle")
def meta_angle(self):
_, result_dtype = elementwise_dtypes(
self, type_promotion_kind=ELEMENTWISE_TYPE_PROMOTION_KIND.INT_TO_FLOAT
)
return self.new_empty(self.size(), dtype=result_dtype)
@torch.library.impl(meta_lib, "angle.out")
def meta_angle_out(self, out):
torch._resize_output_(out, self.size(), self.device)
return out.copy_(torch.angle(self))
def squareCheckInputs(self, f_name):
assert (
self.dim() >= 2
), f"{f_name}: The input tensor must have at least 2 dimensions."
assert self.size(-1) == self.size(
-2
), f"{f_name}: A must be batches of square matrices, but they are {self.size(-2)} by {self.size(-1)} matrices"
def checkUplo(uplo: str):
uplo_uppercase = uplo.upper()
assert (
len(uplo) == 1 and uplo_uppercase == "U" or uplo_uppercase == "L"
), f"Expected UPLO argument to be 'L' or 'U', but got {uplo}"
# Keeping this meta impl around, but we don't want to register it directly to the meta key
# because `aten::linalg_eigh` is composite.
# `_linalg_eigh` is implemented internally as a structured kernel, so we have meta support.
def meta_linalg_eigh(self, uplo="L"):
squareCheckInputs(self, "linalg_eigh")
checkUplo(uplo)
real_dtype = toRealValueType(self.dtype)
assert self.dim() >= 2
values = self.new_empty(self.shape, dtype=real_dtype)
values.transpose_(-2, -1)
vectors = self.new_empty(self.shape[:-1])
return (values, vectors)
@torch.library.impl(meta_lib, "reflection_pad2d")
def meta_pad2d(self, padding):
valid_dims = self.size(1) != 0 and self.size(2) != 0
check(
(self.ndim == 3 and valid_dims)
or (self.ndim == 4 and valid_dims and self.size(3) != 0),
lambda: f"3D or 4D (batch mode) tensor expected for input, but got: {self}",
)
if self.ndim == 4:
nbatch, nplane, input_h, input_w = self.shape
else:
nbatch = 1
nplane, input_h, input_w = self.shape
pad_l, pad_r, pad_t, pad_b = padding
output_h = input_h + pad_t + pad_b
output_w = input_w + pad_l + pad_r
if self.ndim == 3:
return self.new_empty((nplane, output_h, output_w))
else:
return self.new_empty((nbatch, nplane, output_h, output_w))
@torch.library.impl(meta_lib, "dot")
def meta_dot(self, tensor):
check(
self.dim() == 1 and tensor.dim() == 1,
lambda: f"1D tensors expected, but got {self.dim()}D and {tensor.dim()}D tensors",
)
return self.new_empty(())
def _compute_reduction_shape(self, dims, keepdim):
if keepdim:
return tuple(self.shape[i] if i not in dims else 1 for i in range(self.ndim))
return utils.compute_reduction_output_shape(self.shape, dims)
@torch.library.impl(meta_lib, "var_mean.correction")
def meta_var_mean_correction(self, dim, *, correction, keepdim=False):
dim = utils.reduction_dims(self.shape, dim)
output_shape = _compute_reduction_shape(self, dim, keepdim)
result1 = self.new_empty(output_shape, dtype=toRealValueType(self.dtype))
result2 = self.new_empty(output_shape)
return result1, result2
@torch.library.impl(meta_lib, "inverse")
def meta_inverse(self):
# Bug: https://github.com/pytorch/pytorch/issues/77498
if self.numel() == 0:
return torch.empty_like(self)
r = self.new_empty(self.shape)
r.transpose_(-2, -1)
return r
@torch.library.impl(meta_lib, "bernoulli.out")
def meta_bernoulli(self, *, generator=None, out):
torch._resize_output_(out, self.size(), self.device)
return out
@torch.library.impl(meta_lib, "_adaptive_avg_pool2d")
def meta_adaptive_avg_pool2d(self, output_size):
check(
self.ndim == 3 or self.ndim == 4,
lambda: f"Expected 3D or 4D tensor, but got {self.shape}",
)
return self.new_empty(self.shape[:-2] + tuple(output_size))
@torch.library.impl(meta_lib, "_adaptive_avg_pool3d")
def meta_adaptive_avg_pool3d(self, output_size):
check(
self.ndim == 4 or self.ndim == 5,
lambda: f"Expected 4D or 5D tensor, but got {self.shape}",
)
return self.new_empty(self.shape[:-3] + tuple(output_size))
@torch.library.impl(meta_lib, "repeat_interleave.Tensor")
def meta_repeat_interleave_Tensor(repeats, output_size=None):
if output_size is None:
raise RuntimeError("cannot repeat_interleave a meta tensor without output_size")
return repeats.new_empty(output_size)
# Leaving this function around because a python implementation
# of indexing shape inference is useful,
# but not registering it to the dispatcher because we already
# get shape inference through structured kernels
def meta_index_Tensor(self, indices):
check(indices, lambda: "at least one index must be provided")
# aten::index is the internal advanced indexing implementation
# checkIndexTensorTypes and expandTensors
result: List[Optional[Tensor]] = []
for i, index in enumerate(indices):
if index is not None:
check(
index.dtype in [torch.long, torch.int8, torch.bool],
lambda: "tensors used as indices must be long, byte or bool tensors",
)
if index.dtype in [torch.int8, torch.bool]:
nonzero = index.nonzero()
k = len(result)
check(
k + index.ndim <= self.ndim,
lambda: f"too many indices for tensor of dimension {self.ndim}",
IndexError,
)
for j in range(index.ndim):
check(
index.shape[j] == self.shape[k + j],
lambda: f"The shape of the mask {index.shape} at index {i} "
f"does not match the shape of the indexed tensor {self.shape} at index {k + j}",
IndexError,
)
result.append(nonzero.select(1, j))
else:
result.append(index)
else:
result.append(index)
indices = result
check(
len(indices) <= self.ndim,
lambda: f"too many indices for tensor of dimension {self.ndim} (got {len(indices)})",
)
# expand_outplace
import torch._refs as refs # avoid import cycle in mypy
indices = list(refs._maybe_broadcast(*indices))
# add missing null tensors
while len(indices) < self.ndim:
indices.append(None)
# hasContiguousSubspace
# true if all non-null tensors are adjacent
# See:
# https://numpy.org/doc/stable/user/basics.indexing.html#combining-advanced-and-basic-indexing
# https://stackoverflow.com/questions/53841497/why-does-numpy-mixed-basic-advanced-indexing-depend-on-slice-adjacency
state = 0
has_contiguous_subspace = False
for index in indices:
if state == 0:
if index is not None:
state = 1
elif state == 1:
if index is None:
state = 2
else:
if index is not None:
break
else:
has_contiguous_subspace = True
# transposeToFront
# This is the logic that causes the newly inserted dimensions to show up
# at the beginning of the tensor, if they're not contiguous
if not has_contiguous_subspace:
dims = []
transposed_indices = []
for i, index in enumerate(indices):
if index is not None:
dims.append(i)
transposed_indices.append(index)
for i, index in enumerate(indices):
if index is None:
dims.append(i)
transposed_indices.append(index)
self = self.permute(dims)
indices = transposed_indices
# AdvancedIndex::AdvancedIndex
# Now we can assume the indices have contiguous subspace
# This is simplified from AdvancedIndex which goes to more effort
# to put the input and indices in a form so that TensorIterator can
# take them. If we write a ref for this, probably that logic should
# get implemented
before_shape: List[int] = []
after_shape: List[int] = []
replacement_shape: List[int] = []
for dim, index in enumerate(indices):
if index is None:
if replacement_shape:
after_shape.append(self.shape[dim])
else:
before_shape.append(self.shape[dim])
else:
replacement_shape = list(index.shape)
return self.new_empty(before_shape + replacement_shape + after_shape)
@torch.library.impl(meta_lib, "addbmm")
@torch.library.impl(meta_lib, "addbmm.out")
@out_wrapper()
def meta_addbmm(self, batch1, batch2, *, beta=1, alpha=1):
dim1 = batch1.size(1)
dim2 = batch2.size(2)
self = self.expand((dim1, dim2))
check(batch1.dim() == 3, lambda: "batch1 must be a 3D tensor")
check(batch2.dim() == 3, lambda: "batch2 must be a 3D tensor")
check(
batch1.size(0) == batch2.size(0),
lambda: f"batch1 and batch2 must have same number of batches, got {batch1.size(0)} and {batch2.size(0)}",
)
check(
batch1.size(2) == batch2.size(1),
lambda: (
f"Incompatible matrix sizes for bmm ({batch1.size(1)}x{batch1.size(2)} "
f"and {batch2.size(1)}x{batch2.size(2)})"
),
)
check(
self.size(0) == dim1 and self.size(1) == dim2,
lambda: "self tensor does not match matmul output shape",
)
return self.new_empty(self.size())
@torch.library.impl(meta_lib, "_cdist_forward")
def meta_cdist_forward(x1, x2, p, compute_mode):
check(
x1.dim() >= 2,
lambda: f"cdist only supports at least 2D tensors, X1 got: {x1.dim()}D",
)
check(
x2.dim() >= 2,
lambda: f"cdist only supports at least 2D tensors, X2 got: {x2.dim()}D",
)
check(
x1.size(-1) == x2.size(-1),
lambda: f"X1 and X2 must have the same number of columns. X1: {x1.size(-1)} X2: {x2.size(-1)}",
)
check(
utils.is_float_dtype(x1.dtype),
lambda: "cdist only supports floating-point dtypes, X1 got: {x1.dtype}",
)
check(
utils.is_float_dtype(x2.dtype),
lambda: "cdist only supports floating-point dtypes, X2 got: {x2.dtype}",
)
check(p >= 0, lambda: "cdist only supports non-negative p values")
check(
compute_mode >= 0 and compute_mode <= 2,
lambda: f"possible modes: 0, 1, 2, but was: {compute_mode}",
)
r1 = x1.size(-2)
r2 = x2.size(-2)
batch_tensor1 = x1.shape[:-2]
batch_tensor2 = x2.shape[:-2]
output_shape = list(torch.broadcast_shapes(batch_tensor1, batch_tensor2))
output_shape.extend([r1, r2])
return x1.new_empty(output_shape)
@torch.library.impl(meta_lib, "_embedding_bag")
def meta_embedding_bag(
weight,
indices,
offsets,
scale_grad_by_freq=False,
mode=0,
sparse=False,
per_sample_weights=None,
include_last_offset=False,
padding_idx=-1,
):
check(
indices.dtype in (torch.long, torch.int),
lambda: f"expected indices to be long or int, got {indices.dtype}",
)
check(
offsets.dtype in (torch.long, torch.int),
lambda: f"expected offsets to be long or int, got {offsets.dtype}",
)
check(
utils.is_float_dtype(weight.dtype),
lambda: f"expected weight to be floating point type, got {weight.dtype}",
)
num_bags = offsets.size(0)
if include_last_offset:
check(
num_bags >= 1, lambda: "include_last_offset: numBags should be at least 1"
)
num_bags -= 1
output = weight.new_empty(num_bags, weight.size(1))
MODE_SUM, MODE_MEAN, MODE_MAX = range(3)
if per_sample_weights is not None:
check(
mode == MODE_SUM,
lambda: "embedding_bag: per_sample_weights only supported with mode='sum'",
)
check(
per_sample_weights.dtype == weight.dtype,
lambda: f"expected weight ({weight.dtype}) and per_sample_weights ({per_sample_weights.dtype}) to have same dtype",
)
check(
per_sample_weights.ndim == 1,
lambda: f"expected per_sample_weights to be 1D tensor, got {per_sample_weights.ndim}D",
)
check(
per_sample_weights.numel() == indices.numel(),
lambda: (
f"expected per_sample_weights.numel() ({per_sample_weights.numel()} "
f"to be the same as indices.numel() ({indices.numel()})"
),
)
def is_fast_path_index_select_scale(src, scale, output, padding_idx):
return (
is_fast_path_index_select(src, output, padding_idx) and scale.stride(0) == 1
)
def is_fast_path_index_select(src, output, padding_idx):
return (
(src.dtype == torch.float or src.dtype == torch.half)
and src.stride(1) == 1
and output.stride(1) == 1
and padding_idx < 0
)
def is_fast_path(src, scale, output, padding_idx):
if scale is not None:
return is_fast_path_index_select_scale(src, scale, output, padding_idx)
else:
return is_fast_path_index_select(src, output, padding_idx)
if offsets.device.type != "cpu":
offset2bag = indices.new_empty(indices.size(0))
bag_size = indices.new_empty(offsets.size())
if mode == MODE_MAX:
max_indices = indices.new_empty(num_bags, weight.size(1))
else:
max_indices = indices.new_empty(0)
else:
fast_path_sum = is_fast_path(weight, per_sample_weights, output, padding_idx)
if mode == MODE_MEAN or mode == MODE_MAX or not fast_path_sum:
offset2bag = offsets.new_empty(indices.size(0))
else:
offset2bag = offsets.new_empty(0)
bag_size = offsets.new_empty(num_bags)
max_indices = offsets.new_empty(bag_size.size())
return output, offset2bag, bag_size, max_indices
@torch.library.impl(meta_lib, "diag")
@torch.library.impl(meta_lib, "diag.out")
@out_wrapper()
def meta_diag(self, dim=0):
check(self.dim() in (1, 2), lambda: "matrix or a vector expected")
if self.dim() == 1:
sz = self.size(0) + abs(dim)
return self.new_empty((sz, sz))
# case: dim is 2
if dim >= 0:
sz = min(self.size(0), self.size(1) - dim)
else:
sz = min(self.size(0) + dim, self.size(1))
return self.new_empty((sz,))
@torch.library.impl(meta_lib, "_embedding_bag_forward_only")
def meta_embedding_bag_forward_only(weight, indices, offsets, *args):
output, offset2bag, bag_size, max_indices = meta_embedding_bag(
weight, indices, offsets, *args
)
if offsets.device.type == "cpu":
bag_size = offsets.new_empty(offsets.size())
return output, offset2bag, bag_size, max_indices
def _get_reduction_dtype(input, dtype, promote_int_to_long=True):
# if specified, dtype takes precedence
if dtype:
return dtype
if input.dtype.is_floating_point or input.dtype.is_complex:
return input.dtype
elif promote_int_to_long:
return torch.long
return input.dtype
@torch.library.impl(meta_lib, "nansum")
@torch.library.impl(meta_lib, "nansum.out")
@out_wrapper()
def meta_nansum(input, dims=None, keepdim=False, *, dtype=None):
output_dtype = _get_reduction_dtype(input, dtype, promote_int_to_long=True)
dims = utils.reduction_dims(input.shape, dims)
output_shape = _compute_reduction_shape(input, dims, keepdim)
return input.new_empty(output_shape, dtype=output_dtype)
@torch.library.impl(meta_lib, "nanmedian")
def meta_nanmedian(input):
output_shape = utils.compute_reduction_output_shape(
input.shape, tuple(range(input.dim()))
)
return input.new_empty(output_shape)
@torch.library.impl(meta_lib, "nanmedian.dim_values")
@torch.library.impl(meta_lib, "nanmedian.dim")
@out_wrapper("values", "indices")
def meta_nanmedian_dim(input, dim=-1, keepdim=False):
dim = utils.reduction_dims(input.shape, (dim,))
output_shape = _compute_reduction_shape(input, dim, keepdim)
return input.new_empty(output_shape), input.new_empty(
output_shape, dtype=torch.long
)
@torch.library.impl(meta_lib, "nan_to_num")
def meta_nan_to_num(self, nan=None, posinf=None, neginf=None):
return self.new_empty(self.shape)
@torch.library.impl(meta_lib, "remainder.Scalar_Tensor")
def meta_remainder_scalar(scalar, other):
return other % scalar
@torch.library.impl(meta_lib, "logical_not_")
def meta_logical_not_(self):
return self
# We must also trigger meta registrations from PrimTorch ref
# decompositions
import torch._refs
import torch._refs.nn.functional
import torch._refs.special