Summary:
Changelog:
- Port `symeig` from TH/THC to ATen
- Enable batching of matrix inputs for `symeig`
- Modify derivative computation based on batching
- Update docs to reflect the change
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21858
Test Plan: - Added additional tests in `test_torch.py` (with a port to `test_cuda.py`) and `common_methods_invocations.py` to test if both the port and batching work.
Differential Revision: D15981789
Pulled By: soumith
fbshipit-source-id: ab9af8361f8608db42318aabc8421bd99a1ca7ae
Summary:
This change is backwards incompatible in *C++ only* on mean(), sum(), and prod() interfaces that accepted either of:
```
Tensor sum(IntArrayRef dim, bool keepdim=false) const;
Tensor sum(IntArrayRef dim, ScalarType dtype) const;
```
but now to specify both the dim and dtype will require the keepdim parameter:
```
Tensor sum(IntArrayRef dim, bool keepdim=false, c10::optional<ScalarType> dtype=c10::nullopt) const;
```
[xla ci]
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21088
Reviewed By: ailzhang
Differential Revision: D15944971
Pulled By: nairbv
fbshipit-source-id: 53473c370813d9470b190aa82764d0aea767ed74
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21709
Change the return type from Scalar to double/int64_t so we don't need to do conversion when we call other quantize related aten functions
Differential Revision: D15793003
fbshipit-source-id: 510936c69fa17a4d67340a31ebb03415647feb04
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21852
To enable change of q_scale and q_zero_point in `copy_`
Differential Revision: D15793427
fbshipit-source-id: a7040b5b956d161fd6af6176287f4a4aa877c9be
Summary:
Something flaky is going on with `test_inplace_view_saved_output` on Windows.
With my PR #20598 applied, the test fails, even though there is no obvious reason it should be related, so the PR was reverted.
Based on commenting out various parts of my change and re-building, I think the problem is with the name -- renaming everything from `T` to `asdf` seems to make the test stop failing. I can't be sure that this is actually the case though, since I could just be seeing patterns in non-deterministic build output...
I spoke with colesbury offline and we agreed that it is okay to just disable this test on Windows for now and not block landing the main change. He will look into why it is failing.
**Test Plan:** I will wait to make sure the Windows CI suite passes before landing this.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21175
Differential Revision: D15566970
Pulled By: umanwizard
fbshipit-source-id: edf223375d41faaab0a3a14dca50841f08030da3
Summary:
This PR covers two important points with respect to the QR decomposition:
- batching of input matrices (#7500)
- adding `some` as an option in `torch.qr` akin to NumPy's `mode` option (#10538)
Changelog:
- Enable batching for inputs to `torch.qr`
- Move QR decomposition implementation to ATen (CPU and CUDA)
- Remove existing implementations in TH/THC
- Add a `some` option to `torch.qr` that will enable users to switch between complete and reduced decomposition
- Modify doc strings
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20689
Differential Revision: D15529230
Pulled By: soumith
fbshipit-source-id: 16af82b1d2db8a3a758fa8a5f798d83f5f950efb
Summary:
in functional interfaces we do boolean dispatch, but all to max_pool\*d_with_indices. This change it to emit max_pool\*d op instead when it's not necessary to expose with_indices ops to different backends (for jit).
It also bind max_pool\*d to the torch namespace, which is the same behavior with avg_pool\*d
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19449
Differential Revision: D15016839
Pulled By: wanchaol
fbshipit-source-id: f77cd5f0bcd6d8534c1296d89b061023a8288a2c
Summary:
Make it possible to construct a pinned memory tensor without creating a storage first and without calling pin_memory() function. It is also faster, as copy operation is unnecessary.
Supported functions:
```python
torch.rand_like(t, pin_memory=True)
torch.randn_like(t, pin_memory=True)
torch.empty_like(t, pin_memory=True)
torch.full_like(t, 4, pin_memory=True)
torch.zeros_like(t, pin_memory=True)
torch.ones_like(t, pin_memory=True)
torch.tensor([10,11], pin_memory=True)
torch.randn(3, 5, pin_memory=True)
torch.rand(3, pin_memory=True)
torch.zeros(3, pin_memory=True)
torch.randperm(3, pin_memory=True)
torch.empty(6, pin_memory=True)
torch.ones(6, pin_memory=True)
torch.eye(6, pin_memory=True)
torch.arange(3, 5, pin_memory=True)
```
Part of the bigger: `Remove Storage` plan.
Now compatible with both torch scripts:
` _1 = torch.zeros([10], dtype=6, layout=0, device=torch.device("cpu"), pin_memory=False)`
and
` _1 = torch.zeros([10], dtype=6, layout=0, device=torch.device("cpu"))`
Same checked for all similar functions `rand_like`, `empty_like` and others
It is fixed version of #18455
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18952
Differential Revision: D14801792
Pulled By: VitalyFedyunin
fbshipit-source-id: 8dbc61078ff7a637d0ecdb95d4e98f704d5450ba
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18230
Implementing minimum qtensor API to unblock other workstreams in quantization
Changes:
- Added Quantizer which represents different quantization schemes
- Added qint8 as a data type for QTensor
- Added a new ScalarType QInt8
- Added QTensorImpl for QTensor
- Added following user facing APIs
- quantize_linear(scale, zero_point)
- dequantize()
- q_scale()
- q_zero_point()
Reviewed By: dzhulgakov
Differential Revision: D14524641
fbshipit-source-id: c1c0ae0978fb500d47cdb23fb15b747773429e6c
Summary:
Make it possible to construct a pinned memory tensor without creating a storage first and without calling pin_memory() function. It is also faster, as copy operation is unnecessary.
Supported functions:
```python
torch.rand_like(t, pin_memory=True)
torch.randn_like(t, pin_memory=True)
torch.empty_like(t, pin_memory=True)
torch.full_like(t, 4, pin_memory=True)
torch.zeros_like(t, pin_memory=True)
torch.ones_like(t, pin_memory=True)
torch.tensor([10,11], pin_memory=True)
torch.randn(3, 5, pin_memory=True)
torch.rand(3, pin_memory=True)
torch.zeros(3, pin_memory=True)
torch.randperm(3, pin_memory=True)
torch.empty(6, pin_memory=True)
torch.ones(6, pin_memory=True)
torch.eye(6, pin_memory=True)
torch.arange(3, 5, pin_memory=True)
```
Part of the bigger: `Remove Storage` plan.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18455
Reviewed By: ezyang
Differential Revision: D14672084
Pulled By: VitalyFedyunin
fbshipit-source-id: 9d0997ec00f59500ee018f8b851934d334012124
Summary:
Changelog:
- Renames `btrifact` and `btrifact_with_info` to `lu`to remain consistent with other factorization methods (`qr` and `svd`).
- Now, we will only have one function and methods named `lu`, which performs `lu` decomposition. This function takes a get_infos kwarg, which when set to True includes a infos tensor in the tuple.
- Rename all tests, fix callsites
- Create a tentative alias for `lu` under the name `btrifact` and `btrifact_with_info`, and add a deprecation warning to not promote usage.
- Add the single batch version for `lu` so that users don't have to unsqueeze and squeeze for a single square matrix (see changes in determinant computation in `LinearAlgebra.cpp`)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18435
Differential Revision: D14680352
Pulled By: soumith
fbshipit-source-id: af58dfc11fa53d9e8e0318c720beaf5502978cd8
Summary:
Changelog:
- Renames `trtrs` to `triangular_solve` to remain consistent with `cholesky_solve` and `solve`.
- Rename all tests, fix callsites
- Create a tentative alias for `triangular_solve` under the name `trtrs`, and add a deprecation warning to not promote usage.
- Move `isnan` to _torch_docs.py
- Remove unnecessary imports
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18213
Differential Revision: D14566902
Pulled By: ezyang
fbshipit-source-id: 544f57c29477df391bacd5de700bed1add456d3f
Summary:
Why do we need this workaround? `PythonArgParser` handles these two cases well.
The discussion started at https://github.com/pytorch/pytorch/pull/6201#issuecomment-378724406. The conclusion at that time by goldsborough was:
> Because we wanted to allow `dim=None` in Python and route to a different function. Essentially the problem was wanting to wrap the C++ function in Python. AFAIK there is no way of translating `dim=None` behavior into C++? So Richard and I came up with this strategy
Maybe at that time `PythonArgParser` was not powerful enough to handle the routing of two function with same name but different C++ signature.
Will keep an eye on the CI.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/17103
Differential Revision: D14523503
Pulled By: VitalyFedyunin
fbshipit-source-id: cae3e2678062da2eccd93b51d4050578c7a9ab80
Summary:
Changelog:
- Renames `gesv` to `solve` to remain consistent with `cholesky_solve`.
- Rename all tests, fix callsites
- Create a tentative alias for `solve` under the name `gesv`, and add a deprecated warning to not promote usage.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18060
Differential Revision: D14503117
Pulled By: zou3519
fbshipit-source-id: 99c16d94e5970a19d7584b5915f051c030d49ff5
Summary:
Motivation:
- Earlier, `torch.btrifact` could not handle tensors with greater than 3 dimensions. This is because of the check:
> AT_CHECK(THTensor_(nDimension)(a) == 3, "expected 3D tensor, got size: ", a->sizes());
What is in this PR?:
- Move `btrifact` to ATen
- Remove relation to TH/THC.
- Handle tensors with more than three dimensions
- Tests
- Docs modifications: added a note about the non-pivoting variant.
[blocked due to old magma-cuda binaries]
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14964
Differential Revision: D14405106
Pulled By: soumith
fbshipit-source-id: f051f5d6aaa45f85836a2867176c065733563184
Summary:
The main problem there is with differentiating batch norm statically
is that we make a lot of complex run-time decisions about the backend
we choose. Then, the autograd derivatives are implemented for every
backend separately, which makes sense, because they might be saving
buffers containing different values. To resolve the issue, the forward
op returns an index of the chosen backend, and the backward function
takes it as an argument, such that it knows how to interpret the buffers.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15403
Differential Revision: D14098815
Pulled By: ailzhang
fbshipit-source-id: 7fcd3e6e0566433e81fe8286fb441c1ecaf198ad
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16751
This was made more complicated by the fact that ivalue::IntList
is a thing. So I had to fix all of the sites where we referring
to IValue post facto.
The following codemods were run, in this order:
```
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in IntList IntArrayRef
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in IntArrayRef::create IntList::create
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in ivalue::IntArrayRef ivalue::IntList
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in Tag::IntArrayRef Tag::IntList
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in isIntArrayRef isIntList
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in toIntArrayRef toIntList
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in 'Shared<IntArrayRef>' 'Shared<IntList>'
codemod -m -d . --extensions cc,cpp,cu,cuh,h,hpp,py,cwrap,yaml,in 'intrusive_ptr<IntArrayRef>' 'intrusive_ptr<IntList>'
```
Some manual fixups were done afterwards; they can be reviewed separately
at https://github.com/pytorch/pytorch/pull/16752
Reviewed By: dzhulgakov
Differential Revision: D13954363
fbshipit-source-id: b5c40aacba042402155a2f5a229fa6db7992ac64
Summary:
We have:
- This is an initial stab at creating a type stub `torch/__init__.pyi` .
- This is only tested on Python 3, since that's the only Python version mypy
works on.
- So far, we only aim at doing this for torch functions and torch.Tensor.
- Quite a few methods and functions have to be typed manually. These are
done in `torch/__init__.pyi.in`
For me, PyCharm (the non-paid one) didn't seem to indicate errors in the .pyi when opening and seemed to be able to get the type hint for the few functions I tried, but I don't use PyCharm for my usual PyTorch activities, so I didn't extensively try this out.
An example of a generated PYI is at [this gist](https://gist.github.com/ezyang/bf9b6a5fa8827c52152858169bcb61b1).
Pull Request resolved: https://github.com/pytorch/pytorch/pull/12500
Differential Revision: D13695553
Pulled By: ezyang
fbshipit-source-id: 4566c71913ede4e4c23ebc4a72c17151f94e8e21
Summary:
Partially fixes: https://github.com/pytorch/pytorch/issues/394
Implementation detail:
Codegen is modified to generate codes that looks like below:
```C++
static PyObject * THPVariable_svd(PyObject* self_, PyObject* args, PyObject* kwargs)
{
HANDLE_TH_ERRORS
static PythonArgParser parser({
"svd(Tensor input, bool some=True, bool compute_uv=True, *, TensorList[3] out=None)",
}, /*traceable=*/true);
ParsedArgs<6> parsed_args;
auto r = parser.parse(args, kwargs, parsed_args);
static PyStructSequence_Field fields0[] = {
{"U", ""}, {"S", ""}, {"V", ""}, {nullptr}
};
static PyStructSequence_Desc desc0 = {
"torch.return_types.svd_out", nullptr,
fields0, 3
};
static PyTypeObject type0;
static bool namedtuple_type_initialized0 = false;
if (!namedtuple_type_initialized0) {
PyStructSequence_InitType(&type0, &desc0);
namedtuple_type_initialized0 = true;
}
static PyStructSequence_Field fields1[] = {
{"U", ""}, {"S", ""}, {"V", ""}, {nullptr}
};
static PyStructSequence_Desc desc1 = {
"torch.return_types.svd", nullptr,
fields1, 3
};
static PyTypeObject type1;
static bool namedtuple_type_initialized1 = false;
if (!namedtuple_type_initialized1) {
PyStructSequence_InitType(&type1, &desc1);
namedtuple_type_initialized1 = true;
}
if (r.idx == 0) {
if (r.isNone(3)) {
return wrap(&type1, dispatch_svd(r.tensor(0), r.toBool(1), r.toBool(2)));
} else {
auto results = r.tensorlist_n<3>(3);
return wrap(&type0, dispatch_svd(r.tensor(0), r.toBool(1), r.toBool(2), results[0], results[1], results[2]));
}
}
Py_RETURN_NONE;
END_HANDLE_TH_ERRORS
}
```
Types are defined as static member of `THPVariable_${op_name}` functions, and initialized at the first time the function is called.
When parsing function prototypes in `native_functions.yaml`, the parser will set the specified name as `field_name` when see things like `-> (Tensor t1, ...)`. These field names will be the field names of namedtuple. The class of namedtuples will be named `torch.return_types.${op_name}`.
In some python 2, `PyStructSequence` is not a subtype of tuple, so we have to create some functions to check if an object is a tuple or namedtuple for compatibility issue.
Operators in `native_functions.yaml` are changed such that only `max` and `svd` are generated as namedtuple. Tests are added for these two operators to see if the return value works as expected. Docs for these two ops are also updated to explicitly mention the return value is a namedtuple. More ops will be added in later PRs.
There is some issue with Windows build of linker unable to resolve `PyStructSequence_UnnamedField`, and some workaround is added to deal with this case.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15429
Differential Revision: D13709678
Pulled By: ezyang
fbshipit-source-id: 23a511c9436977098afc49374e9a748b6e30bccf
Summary:
This PR does three things:
~~Allow `int64_t?` in function schema, which provide an elegant way of implementing null-able int arguments, as discussed in https://github.com/pytorch/pytorch/pull/15208#pullrequestreview-185230081~~
~~Originally implemented in https://github.com/pytorch/pytorch/pull/15235~~
~~Example:~~
```yaml
- func: myop(Tensor self, int64_t? dim=None) -> Tensor
variants: function
```
~~cc: zou3519~~
Edit: implemented in https://github.com/pytorch/pytorch/pull/15234
Previously tried in https://github.com/pytorch/pytorch/pull/12064. There was a problem that C++ does not have kwarg support, which makes it confusing to know whether `unique(t, 1)` actually means `unique(t, dim=1)` or `unique(t, sorted=1)`.
Now I think I have a better idea on how to implement this: there are two ATen operators: `unique` and `unique_dim`. `unique` has the same signature as in python, and exported to both python and C++. `unique_dim` has signature `unique_dim(tensor, dim, sorted=False, return_inverse=False)`, and only exported to C++, which could be used more naturally for a C++ user.
Differential Revision: D13540278
Pulled By: wanchaol
fbshipit-source-id: 3768c76a90b0881f565a1f890459ebccbdfe6ecd
Summary:
This PR implements infrastructure for post-processing a model to apply int8 quantization to its `nn.Linear` modules. Highlights of the implementation:
1) Inputs and outputs are `float` (quantized and packed internally), but the weight is quantized and packed ahead of time for efficiency. This implementation performs well in small-batch size GEMM calls. It should not be considered a general-purpose quantized GEMM kernel.
2) Weight packing is dependent on machine architecture (e.g. vector register width), so it is done just-in-time. Concretely, it is done on model load for the weights and it is done during operator execution for the input value.
3) Biases are unquantized
4) We fail loudly if we are attempting to run this on a machine that does not support FBGEMM. This is because we do not want a model's numerics to differ based on which machine it is run on. A model containing these FBGEMM ops *must* be run with FBGEMM
The API can be seen in the added test case. Highlights are:
1) `torch.jit.quantized.quantize_linear_modules` walks the module hierarchy of the passed-in Module and replaces all `nn.Linear` modules with a new `QuantizedLinear` module, which encapsulates the behavior described above.
2) `_pack()` and `_unpack()` script methods are present on `QuantizedLinear` modules. These methods should be called before serialization and after deserialization, respectively. This ensures that the weight matrix is properly packed for the running machine's architecture. Note that in the long term, we would like to move toward a more Pickle-style serialization technique, rather than having these explicit methods that mutate member values. This is blocked on being able to assign attributes in a ScriptMethod, among other things.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/13777
Differential Revision: D13383276
Pulled By: jamesr66a
fbshipit-source-id: 00f29c9f34544add2b90107e3cf55a287802c344
Summary:
Optional clean up. This PR remove python_default_init from the yaml files, and the code-gen, and utilize optional type to do the work.
This also fix the bug in the #13149 to correctly adopt as_strided backward.
Fixes#9941
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15234
Differential Revision: D13502044
Pulled By: wanchaol
fbshipit-source-id: 774b61fc4414482cf11d56e22bd0275aefb352a4
Summary:
For #6593 and #9515
This completes the support for optional<ScalarType> in native, JIT and autograd.
Note: Mostly following the existing implementation for optional<Scalar> that was added in https://github.com/pytorch/pytorch/pull/12582.
This PR introduces a way to make functions accept an optional dtype and it will unblock #9515 by allowing the `dtype` param for type promotion interface:
```
func: name(inputs, *, ScalarType? dtype=None, Casting casting=same_kind)
```
An alternative approach could have been using `ScalarType::Undefined` for the same purpose but without optional, though it would have been a bit hacky.
```
func: name(inputs, *, ScalarType dtype=Undefined, Casting casting=same_kind)
```
Here's an example use of this in action: 971f69eac6
There are already a bunch of native functions that were getting optional `dtype` through function overloading. https://github.com/pytorch/pytorch/pull/15133 is the attempt to migrate all of those. I will send those changes separately after this since some functions (e.g. sum) need quite a bit of change in the codebase. See the commits over there.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15154
Differential Revision: D13457760
Pulled By: tugrulates
fbshipit-source-id: 706134f0bd578683edd416b96329b49a1ba8ab48
Summary:
This is an optimized implementation that does the following:
1. created an empty Tensor of correct size.
2. fill the Tensor with correct values.
The following three designs to fill in the Tensor result in roughly the same performance. Hence, the 2nd option is taken for simpler code, and to return contiguous tensors.
1. Sequential: fill row coordinates first, then columns. This results in two for-loop and more arithmetic operations.
2. Interleaved: fill in index coordinates one by one, which jumps between the two output Tensor rows in every iteration.
3. Transpose: create a n X 2 Tensor, fill the Tensor sequentially, and then transpose it.
<img width="352" alt="screen shot 2018-12-10 at 3 54 39 pm" src="https://user-images.githubusercontent.com/16999635/49769172-07bd3580-fc94-11e8-8164-41839185e9f9.png">
NOTE:
This implementation returns a 2D tensor, instead of a tuple of two tensors. It means that users will not be able to do the following:
```python
x = torch.ones(3, 3)
i = torch.tril_indices(3, 3)
x[i] # need to first convert the 2D tensor into a tuple of two 1D tensors.
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14904
Reviewed By: zou3519
Differential Revision: D13433027
Pulled By: mrshenli
fbshipit-source-id: 41c876aafcf584832d7069f7c5929ffb59e0ae6a
Summary:
Make `at::_local_scalar` more "official" by renaming it to `item()`.
gchanan
Pull Request resolved: https://github.com/pytorch/pytorch/pull/13676
Differential Revision: D13003020
Pulled By: goldsborough
fbshipit-source-id: 0ac25f5237fb81a1576304a0a02f840ff44168a4
Summary:
Implements batching for the Cholesky decomposition.
Performance could be improved with a dedicated batched `tril` and `triu` op, which is also impeding autograd operations.
Changes made:
- batching code
- tests in `test_torch.py`, `test_cuda.py` and `test_autograd.py`.
- doc string modification
- autograd modification
- removal of `_batch_potrf` in `MultivariateNormal`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14017
Differential Revision: D13087945
Pulled By: ezyang
fbshipit-source-id: 2386db887140295475ffc247742d5e9562a42f6e
Summary:
This is needed for moving nn functions to native functions, but since some functions are already named
this way, I'm going to stop binding pre-emptively so we can check if there are any current dependencies.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14101
Differential Revision: D13102219
Pulled By: gchanan
fbshipit-source-id: 6bbcca33a03ab1bf648f1b73cadfe84339fa3050
Summary:
- This is a straightforward PR, building up on the batch inverse PR, except for one change:
- The GENERATE_LINALG_HELPER_n_ARGS macro has been removed, since it is not very general and the resulting code is actually not very copy-pasty.
Billing of changes:
- Add batching for `potrs`
- Add relevant tests
- Modify doc string
Minor changes:
- Remove `_gesv_single`, `_getri_single` from `aten_interned_strings.h`.
- Add test for CUDA `potrs` (2D Tensor op)
- Move the batched shape checking to `LinearAlgebraUtils.h`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/13453
Reviewed By: soumith
Differential Revision: D12942039
Pulled By: zou3519
fbshipit-source-id: 1b8007f00218e61593fc415865b51c1dac0b6a35
Summary:
While using gbenchmark, I found `tensor.resize_({0})` would take 300ns
if tensor already has the correct size. This is important for
`at::empty({0})` perf because `at::empty` always calls `resize_`, which
in turn is a important for JIT perf: the fusion compiler creates empty
tensors and then `resize_`s them to computed sizes. Most of the 300ns is
due to DeviceGuard (200ns)
Summary of findings:
- `at::empty({0}, cuda)`: 851ns
- `empty_tensor.resize({0})`: 308ns
- `DeviceGuard(tensor)`: ctor + dtor: 200ns (Going to look into this
next because it impacts `resize_` perf).
- vdispatch overhead (`tensor.resize_()` vs
`at::native::resize__cuda(tensor)`): ~10ns
This PR rips out the TH `resize_` implementation and adds it to ATen
with the following modifications:
- DeviceGuard used only after the same-size check.
- Same-size check rewritten for simplicity. The new check doesn't
affect perf.
- empty_cpu / empty_cuda avoid the dispatch overhead to
tensor.resize_.
Timing with this PR:
- `at::empty({0}, cuda)`: 363ns
- `empty_tensor.resize_({0})`: 17ns
Future:
- Investigate `resize_(sizes)` slowness when `tensor.sizes() != sizes`
- Should tell resize_as_ to use the new resize_ implementation...
(because resize_as_ is in TH, it is calling the old TH resize_)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/12824
Differential Revision: D10449209
Pulled By: zou3519
fbshipit-source-id: cecae5e6caf390017c07cd44a8eaf2fa6e3fdeb6
