In particular this ensures we release the GIL when serializing:
- PyBytes objects (this is how we get the pickle object)
- Storage objects
Other string-like objects keep the gil which is fine because we only use this for very small strings today (for endianess) and so releasing the GIL is not important there
Co-authored-by: Mikayla Gawarecki <mikaylagawarecki@gmail.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120818
Approved by: https://github.com/colesbury
Fixes https://github.com/pytorch/pytorch/issues/117361
The implementation here slightly diverges from what was proposed in the issue, so I will recap what this PR is doing here. Today, when doing computations involving size-like unbacked SymInts, we assume for all operations that the compile time range of the integer is `[2, inf]`, even though at runtime we also accept zero and one.
This PR removes the carte blanche assumption, and instead does the analysis in a much more limited and controlled fashion: only for guards which we have designated as "size oblivious" are we willing to do the analysis under the assumption that the range of all size-like unbacked SymInts is `[2, inf]`; otherwise, we will faithfully only do analysis with `[0, inf]` (or whatever the user provided) bounds.
The infra pieces of this PR are:
* Remove runtime_var_to_range from torch/fx/experimental/symbolic_shapes.py; modify `_constrain_range_for_size` to refine the range without clamping min to 2, and instead add the symbol to a `size_like` set in the ShapeEnv
* When evaluating an expression, if the expression is requested to be evaluated in a `size_oblivious` way, we attempt to statically compute the value of the expression with the assumption that all symbols in `size_like` are updated to assume that they are `>= 2`.
* Add Python and C++ APIs for guarding on a SymBool in a size-oblivious way. In C++, I also need to add some helpers for performing symbolic comparisons, since the stock comparisons immediately specialize in the "normal" way.
The rest of the changes of the PR are marking various spots in PyTorch framework code as size oblivious, based on what our current test suite exercises.
As you review the places where we have marked things as size oblivious, it may become clear why I ended up not opting for the "designate a branch as the default branch when it's not statically obvious which way to go": for some of the conditions, this answer is rather non-obvious. I think potentially there is another refinement on top of this PR, which is something like "I don't care if you can't figure it out with ValueRange analysis, go down this path anyway if there are unbacked sizes involved." But even if we add this API, I think we are obligated to attempt the ValueRange analysis first, since it can lead to better outcomes sometimes (e.g., we are able to figure out that something is contiguous no matter what the unbacked size is.)
When is it permissible to mark something as size oblivious? Heuristically, it is OK anywhere in framework code if it gets you past a guard on unbacked SymInt problem. It is somewhat difficult to provide a true semantic answer, however. In particular, these annotations don't have any observational equivalence guarantee; for example, if I have `torch.empty(u0, 1).squeeze()`, we will always produce a `[u0]` size tensor, even though if `u0 == 1` PyTorch will actually produce a `[]` size tensor. The argument that I gave to Lezcano is that we are in fact defining an alternate semantics for a "special" size = 0, 1, for which we have these alternate eager mode semantics. In particular, suppose that we have a constant `special1` which semantically denotes 1, but triggers alternate handling rules. We would define `torch.empty(special1, 1).squeeze()` to always produce a `[special1]` size tensor, making its semantics coincide with unbacked SymInt semantics. In this model, the decision to designate guards as size oblivious is simply a user API question: you put them where ever you need some handling for special1! As we conservatively error out whenever it is not obvious what `special1` semantics should be, it is always valid to expand these semantics to cover more cases (although you can always choose the wrong semantics!)
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118579
Approved by: https://github.com/eellison, https://github.com/lezcano
Summary:
See internal diff for more changes. Whenever we encounter a non-compliant op,
we add it to a set on the OutputGraph. When a compilation event happens, we log
the contents of this set.
I'm planning on flipping the `only_allow_pt2_compliant_ops` config from False
to True after the logging determines that existing models do not use
non-compliant ops.
Test Plan: - Tested the logging internally locally
Differential Revision: D50884828
Pull Request resolved: https://github.com/pytorch/pytorch/pull/112581
Approved by: https://github.com/yanboliang
I need this for later. This roughly returns all the OpOverloads
for an OpOverloadPacket in the order that the OpOverloadPacket decides
to resolve them in.
Test Plan:
- wait for CI
Pull Request resolved: https://github.com/pytorch/pytorch/pull/112198
Approved by: https://github.com/ezyang
Summary:
When raising an exception here this causes pybind11's dispatcher to kick in, which causes aiplatform's logic to kick in (aiplatform::error_reporting::util::printAddressesWithBestEffortLocationInfo), which ultimately uses `folly::symbolizer::Symbolizer::symbolize` for building up the stack trace. In 3.8 this uses about 3.62% of the CPU time per pyperf (https://fburl.com/scuba/pyperf_experimental/on_demand/oi554uvy). In Cinder 3.8 for some reason this is worse - using 5.94% of the CPU.
This exception is happening when doing a hasattr() on `prims` for things like `bitwise_left_shift` which don't exist: https://www.internalfb.com/code/fbsource/[2d695f650d00]/fbcode/caffe2/torch/_inductor/lowering.py?lines=590
That exception is ultimately going to be swallowed anyway, and the stack trace has no meaningful value. Furthermore because this is kind of an expected outcome in the code versus some random C++ exception the stack trace is less valuable as well.
This changes this to return a (None, None) on the failure case instead of returning a valid op/overload list, avoiding the exception, and reclaiming the 3.62%-5.94% of time.
Test Plan: Existing CI and perf run: https://fburl.com/scuba/pyperf_experimental/on_demand/oi554uvy
Differential Revision: D50018789
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111438
Approved by: https://github.com/davidberard98
Removes the existing integration code & build of nvfuser in TorchScript.
Note that I intentionally left the part where we wipe out `third_party/nvfuser` repo. I'll do that in a separate PR.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111093
Approved by: https://github.com/albanD
We want to be able to use SingletonSymNode to represent strides for Jagged layout tensor. The following is for 3D, but easily generalizable to higher dimensions.
Constraints:
- [B, x, D] (where x represents the "variably lengthed dim") can be strided in two ways [x, 1, sum(x)] and [dx, d, 1]. We need two different placeholder values depending on how the jagged tensor is strided.
- When doing operations we need the strides of output tensors to be expressable in terms of the strides and sizes of the inner tensors. Given [B, x, D] @ [D, D'], the output strides is [x * D', D', 1] rather than some opaque [x2, D', 1]. This constraint exists because if I'm tracing, I need a symint to represent the output stride. This symint needs to come from somewhere; I get it in several ways: (1) create a constant, (2) unbacked symint, (3) create a new input using a source, (4) output of an operation on an existing symint. It is clear that (4) is what we want here, which brings us to the design below.
Design:
Given the two constraints, the most straightforward way to implement this is actually to update SingletonSymNode to include some scalar factor, i.e. Morally, SingletonSymNode represents `factor * [s_0, s_1, …, s_n]` This enables us to symbolically compute strides from sizes.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110369
Approved by: https://github.com/ezyang
ghstack dependencies: #110044
Removing the functionalities from nvfuser python APIs.
Since the use of nvfuser has been deprecated before the last release cut. We are removing torch script support.
I'll have the next PR to actually remove the code base.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110124
Approved by: https://github.com/davidberard98
Bugfix:
- previously, SymBool does not implement `__eq__`, Python falls back to default `__eq__ `and `__hash__`
- in this PR, we make SymBool implement `__eq__`
- symbolic SymBool now raises an error when hashed just like SymInt/SymFloat
New feature:
- previously, SymInt and SymFloat are unhashable (even if you are singleton or constant)
- in this PR, SymInt and SymBool are hashable if singleton/constant
Stay the same:
- SymNode are hashable due to default Python behavior
Pull Request resolved: https://github.com/pytorch/pytorch/pull/109170
Approved by: https://github.com/ezyang
ghstack dependencies: #109169
In this PR:
- When Constant SymNode are detected in unary/binary ops demote them to plain int/bool before proceeding. Sometimes this means doing a unary op with a Constant SymNode would result in a plain bool.
- Introduce an is_symbolic method, only available from Python. We need this because isinstance(x, SymInt) is no longer sufficient to check whether a given int/SymInt is symbolic or not. See later PR in the stack to see how this is used.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/109169
Approved by: https://github.com/ezyang
Summary:
In fbcode, aten and jit ops can get registered in different orders depending on build mode. In dev mode, aten is registered first; in opt mode, jit is registered first.
This causes problems in torch.ops.aten.* calls; these calls use `torch._C._jit_get_operation`, which selects an overload based on the inputs to the call. It searches through the overloads for the op with the given name, and chooses the first one that matches the input types. "First" depends on whether aten or jit ops were registered first - e.g. in `test_both_scalars_cuda` in opt mode, it chooses `add.complex` and returns a complex value.
We also saw this issue in https://github.com/pytorch/pytorch/pull/103576.
This PR sorts the list of overloads first, putting the aten ops first.
Differential Revision: D48304930
Pull Request resolved: https://github.com/pytorch/pytorch/pull/107138
Approved by: https://github.com/ezyang, https://github.com/eellison
This pattern shows up in torchrec KeyedJaggedTensor. Most
of the change in this PR is mechanical: whenever we failed
an unbacked symint test due to just error checking, replace the
conditional with something that calls expect_true (e.g.,
torch._check or TORCH_SYM_CHECK).
Some of the changes are a bit more nuanced, I've commented on the PR
accordingly.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/106788
Approved by: https://github.com/lezcano
ghstack dependencies: #106720
Here's what it does from the comments:
```
Assume that a boolean is true for the purposes of subsequent symbolic
reasoning. This will keep track of corresponding runtime checks to verify
that the result is upheld: either as a regular guard, or as a special set
of asserts which are triggered when an unbacked SymInt is allocated.
DO NOT use this function for these cases:
- This is inappropriate for "branching" conditions (where both
true and false result in valid programs). We will always assume
the condition evaluates true, and so it will never be possible
to trace the false condition when you use it. For true branching
on unbacked SymInts, you must use torch.cond.
- This is inappropriate for situations where you know some other system
invariant guarantees that this property holds, since you don't
really need to insert a runtime check in that case. Use something
like constrain_range in that case.
This API has a hitch. To avoid having to reimplement error reporting
capabilities, this function CAN return False. The invariant is that
the surrounding code must raise an error when this function returns
False. This is quite low level, so we recommend using other functions
like check() which enforce this in a more intuitive way.
By the way, this name is a nod to the __builtin_expect likely macro,
which is used similarly (but unlike __builtin_expect, you MUST fail
in the unlikely branch.)
```
We don't do anything with this right now, except use it to discharge regular guards. Follow up PRs to (1) use it at important error checking sites, (2) actually ensure the runtime asserts make there way into the exported IR / inductor generated code.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/106720
Approved by: https://github.com/ysiraichi, https://github.com/voznesenskym
Using [`nanoGPT/model.py`](https://github.com/karpathy/nanoGPT/blob/master/model.py) run
<details><summary><b>Click for script to save gpt2-xlarge (1.5B params)</b></summary>
```
# test_load_save_gpt.py
from model import GPT
import torch
import time
torch.manual_seed(5)
# gpt2-xlarge 1558M parameters
class GPTConfig:
block_size: int = 1024
vocab_size: int = 50304 # GPT-2 vocab_size of 50257, padded up to nearest multiple of 64 for efficiency
n_layer: int = 48
n_head: int = 25
n_embd: int = 1600
dropout: float = 0.0
bias: bool = True # True: bias in Linears and LayerNorms, like GPT-2. False: a bit better and faster
def f():
model = GPT(GPTConfig())
state_dict = model.state_dict()
start_saving = time.time()
torch.save(state_dict, "gpt2-xlarge.pth")
end_saving = time.time()
if __name__ == "__main__":
f()
```
</details>
<details><summary><b>Click for script to load</b></summary>
```
# test_load_gpt.py
import torch
from model import GPT
from test_load_save_gpt import GPTConfig
import time
import argparse
def f(mmap, meta):
device = 'meta' if meta else 'cpu'
assign = True if meta else False
with torch.device(device):
model = GPT(GPTConfig())
start_loading = time.time()
loaded_state_dict = torch.load("gpt2-xlarge.pth", _mmap=mmap)
end_loading = time.time()
print(f"loading time using torch.load with mmap={mmap}: ", end_loading - start_loading)
model.load_state_dict(loaded_state_dict, assign=assign)
end_load_state_dict = time.time()
print("load_state_dict time: ", end_load_state_dict - end_loading)
model.cuda()
end_cuda = time.time()
print("cuda time using torch.load with mmap: ", end_cuda - end_load_state_dict)
if __name__ == "__main__":
parser = argparse.ArgumentParser(prog='load_gpt_xlarge')
parser.add_argument('-m', '--mmap', action='store_true')
parser.add_argument('-d', '--devicemeta', action='store_true')
args = parser.parse_args()
mmap = args.mmap
meta = args.devicemeta
f(mmap, meta)
```
</details>
`python test_load_gpt.py`
<img width="614" alt="Screenshot 2023-06-06 at 1 35 43 PM" src="https://github.com/pytorch/pytorch/assets/35276741/ee06e5b3-b610-463b-a867-df995d21af29">
`python test_load_gpt.py --mmap`
<img width="622" alt="Screenshot 2023-06-06 at 1 35 30 PM" src="https://github.com/pytorch/pytorch/assets/35276741/00d2fdd0-b1f5-4313-83dc-e540b654b2af">
If we further use the `with torch.device('meta')` context manager and pull the changes from https://github.com/pytorch/pytorch/pull/102212 that allow the model to reuse tensors from the state_dict, we have
`python test_load_gpt.py --mmap --devicemeta`
<img width="727" alt="Screenshot 2023-06-06 at 1 35 51 PM" src="https://github.com/pytorch/pytorch/assets/35276741/b50257d9-092a-49c3-acae-876ee44d009f">
\
\
Running the above in a docker container containing a build of PyTorch with RAM limited to 512mb by
1) running `make -f docker.Makefile` from `pytorch/` directory
2) `docker run -m 512m -it <image> bash`
3) docker cp `gpt2-xlarge.pth` and `test_load_gpt.py` into the image
`python test_load_gpt.py`
Docker will Kill the process due to OOM whereas
`python test_load_gpt.py --mmap --devicemeta`
<img width="635" alt="Screenshot 2023-06-06 at 1 55 48 PM" src="https://github.com/pytorch/pytorch/assets/35276741/f3820d9e-f24c-43e7-885b-3bfdf24ef8ad">
Pull Request resolved: https://github.com/pytorch/pytorch/pull/102549
Approved by: https://github.com/albanD
Summary:
In order to better track models after serialization, this change writes a serialization_id as a UUID to inline container. Having this ID enables traceability of model in saving and loading events.
serialization_id is generated as a new UUID everytime serialization takes place. It can be thought of as a model snapshot identifier at the time of serialization.
Test Plan:
```
buck2 test @//mode/dev //caffe2/caffe2/serialize:inline_container_test
```
Local tests:
```
buck2 run @//mode/opt //scripts/atannous:example_pytorch_package
buck2 run @//mode/opt //scripts/atannous:example_pytorch
buck2 run @//mode/opt //scripts/atannous:example_pytorch_script
```
```
$ unzip -l output.pt
Archive: output.pt
Length Date Time Name
--------- ---------- ----- ----
36 00-00-1980 00:00 output/.data/serialization_id
358 00-00-1980 00:00 output/extra/producer_info.json
58 00-00-1980 00:00 output/data.pkl
261 00-00-1980 00:00 output/code/__torch__.py
326 00-00-1980 00:00 output/code/__torch__.py.debug_pkl
4 00-00-1980 00:00 output/constants.pkl
2 00-00-1980 00:00 output/version
--------- -------
1045 7 files
```
```
unzip -p output.pt "output/.data/serialization_id"
a9f903df-cbf6-40e3-8068-68086167ec60
```
Differential Revision: D45683657
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100994
Approved by: https://github.com/davidberard98
The basic idea behind this PR is that we want to continue using the guarding implementations of contiguity tests, if all of the elements are backend (aka, have hints). If they don't have hints, we'll have to do something slower (use the non-short circuiting, non guarding implementations of contiguity), but most of the time you aren't dealing with unbacked SymInts.
So this PR has three parts.
1. We expose `has_hint` on `SymNode`. This allows us to query whether or not a SymInt is backed or not from C++. Fairly self explanatory. Will require LTC/XLA updates; but for backends that don't support unbacked SymInts you can just always return true.
2. We update `compute_non_overlapping_and_dense` to test if the inputs are hinted. If they are all hinted, we use the conventional C++ implementation. Otherwise we call into Python. The Python case is not heavily tested right now because I haven't gotten all of the pieces for unbacked SymInts working yet. Coming soon.
3. We add stubs for all of the other contiguity tests. The intention is to apply the same treatment to them as well, but this is not wired up yet for safety reasons.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/94431
Approved by: https://github.com/voznesenskym
We want to make TorchRec sharded models TorchScriptable.
TorchRec sharded models uses generic types Awaitable[W] and LazyAwaitable[W] (https://github.com/pytorch/torchrec/blob/main/torchrec/distributed/types.py#L212).
In sharded model those types are used instead of contained type W, having the initialization function that produces object of type W.
At the moment when the first attribute of W is requested - `LazyAwaitable[W]` will call its initialization function (on the same stack), cache the result inside and work transparently as an object of W. So we can think about it as a delayed object initialization.
To support this behavior in TorchScript - we propose a new type to TorchScript - `Await`.
In eager mode it works the same as `LazyAwaitable[W]` in TorchRec, being dynamically typed - acting as a type `W` while it is `Await[W]`.
Within torchscript it is `Await[W]` and can be only explicitly converted to W, using special function `torch.jit.awaitable_wait(aw)`.
Creation of this `Await[W]` is done via another special function `torch.jit.awaitable(func, *args)`.
The semantic is close to `torch.jit.Future`, fork, wait and uses the same jit mechanics (inline fork Closures) with the difference that it does not start this function in parallel on fork. It only stores as a lambda inside IValue that will be called on the same thread when `torch.jit.awaitable_wait` is called.
For example (more examples in this PR `test/jit/test_await.py`)
```
def delayed(z: Tensor) -> Tensor:
return Tensor * 3
@torch.jit.script
def fn(x: Tensor):
aw: Await[int] = torch.jit._awaitable(delayed, 99)
a = torch.eye(2)
b = torch.jit._awaitable_wait(aw)
return a + b + x
```
Functions semantics:
`_awaitable(func -> Callable[Tuple[...], W], *args, **kwargs) -> Await[W]`
Creates Await object, owns args and kwargs. Once _awaitable_wait calls, executes function func and owns the result of the function. Following _awaitable_wait calls will return this result from the first function call.
`_awaitable_wait(Await[W]) -> W`
Returns either cached result of W if it is not the first _awaitable_wait call to this Await object or calls specified function if the first.
`_awaitable_nowait(W) -> Await[W]`
Creates trivial Await[W] wrapper on specified object To be type complaint for the corner cases.
Differential Revision: [D42502706](https://our.internmc.facebook.com/intern/diff/D42502706)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/90863
Approved by: https://github.com/davidberard98
Not only is this change usually shorter and more readable, it also can yield better performance. size() is not always a constant time operation (such as on LinkedLists), but empty() always is.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/93236
Approved by: https://github.com/malfet
This PR is the first step towards refactors the build for nvfuser in order to have the coegen being a standalone library.
Contents inside this PR:
1. nvfuser code base has been moved to `./nvfuser`, from `./torch/csrc/jit/codegen/cuda/`, except for registration code for integration (interface.h/interface.cpp)
2. splits the build system so nvfuser is generating its own `.so` files. Currently there are:
- `libnvfuser_codegen.so`, which contains the integration, codegen and runtime system of nvfuser
- `nvfuser.so`, which is nvfuser's python API via pybind. Python frontend is now exposed via `nvfuser._C.XXX` instead of `torch._C._nvfuser`
3. nvfuser cpp tests is currently being compiled into `nvfuser_tests`
4. cmake is refactored so that:
- nvfuser now has its own `CMakeLists.txt`, which is under `torch/csrc/jit/codegen/cuda/`.
- nvfuser backend code is not compiled inside `libtorch_cuda_xxx` any more
- nvfuser is added as a subdirectory under `./CMakeLists.txt` at the very end after torch is built.
- since nvfuser has dependency on torch, the registration of nvfuser at runtime is done via dlopen (`at::DynamicLibrary`). This avoids circular dependency in cmake, which will be a nightmare to handle. For details, look at `torch/csrc/jit/codegen/cuda/interface.cpp::LoadingNvfuserLibrary`
Future work that's scoped in following PR:
- Currently since nvfuser codegen has dependency on torch, we need to refactor that out so we can move nvfuser into a submodule and not rely on dlopen to load the library. @malfet
- Since we moved nvfuser into a cmake build, we effectively disabled bazel build for nvfuser. This could impact internal workload at Meta, so we need to put support back. cc'ing @vors
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89621
Approved by: https://github.com/davidberard98
We have known for a while that we should in principle support SymBool as a separate concept from SymInt and SymFloat ( in particular, every distinct numeric type should get its own API). However, recent work with unbacked SymInts in, e.g., https://github.com/pytorch/pytorch/pull/90985 have made this a priority to implement. The essential problem is that our logic for computing the contiguity of tensors performs branches on the passed in input sizes, and this causes us to require guards when constructing tensors from unbacked SymInts. Morally, this should not be a big deal because, we only really care about the regular (non-channels-last) contiguity of the tensor, which should be guaranteed since most people aren't calling `empty_strided` on the tensor, however, because we store a bool (not a SymBool, prior to this PR it doesn't exist) on TensorImpl, we are forced to *immediately* compute these values, even if the value ends up not being used at all. In particular, even when a user allocates a contiguous tensor, we still must compute channels-last contiguity (as some contiguous tensors are also channels-last contiguous, but others are not.)
This PR implements SymBool, and makes TensorImpl use SymBool to store the contiguity information in ExtraMeta. There are a number of knock on effects, which I now discuss below.
* I introduce a new C++ type SymBool, analogous to SymInt and SymFloat. This type supports logical and, logical or and logical negation. I support the bitwise operations on this class (but not the conventional logic operators) to make it clear that logical operations on SymBool are NOT short-circuiting. I also, for now, do NOT support implicit conversion of SymBool to bool (creating a guard in this case). This does matter too much in practice, as in this PR I did not modify the equality operations (e.g., `==` on SymInt) to return SymBool, so all preexisting implicit guards did not need to be changed. I also introduced symbolic comparison functions `sym_eq`, etc. on SymInt to make it possible to create SymBool. The current implementation of comparison functions makes it unfortunately easy to accidentally introduce guards when you do not mean to (as both `s0 == s1` and `s0.sym_eq(s1)` are valid spellings of equality operation); in the short term, I intend to prevent excess guarding in this situation by unit testing; in the long term making the equality operators return SymBool is probably the correct fix.
* ~~I modify TensorImpl to store SymBool for the `is_contiguous` fields and friends on `ExtraMeta`. In practice, this essentially meant reverting most of the changes from https://github.com/pytorch/pytorch/pull/85936 . In particular, the fields on ExtraMeta are no longer strongly typed; at the time I was particularly concerned about the giant lambda I was using as the setter getting a desynchronized argument order, but now that I have individual setters for each field the only "big list" of boolean arguments is in the constructor of ExtraMeta, which seems like an acceptable risk. The semantics of TensorImpl are now that we guard only when you actually attempt to access the contiguity of the tensor via, e.g., `is_contiguous`. By in large, the contiguity calculation in the implementations now needs to be duplicated (as the boolean version can short circuit, but the SymBool version cannot); you should carefully review the duplicate new implementations. I typically use the `identity` template to disambiguate which version of the function I need, and rely on overloading to allow for implementation sharing. The changes to the `compute_` functions are particularly interesting; for most of the functions, I preserved their original non-symbolic implementation, and then introduce a new symbolic implementation that is branch-less (making use of our new SymBool operations). However, `compute_non_overlapping_and_dense` is special, see next bullet.~~ This appears to cause performance problems, so I am leaving this to an update PR.
* (Update: the Python side pieces for this are still in this PR, but they are not wired up until later PRs.) While the contiguity calculations are relatively easy to write in a branch-free way, `compute_non_overlapping_and_dense` is not: it involves a sort on the strides. While in principle we can still make it go through by using a data oblivious sorting network, this seems like too much complication for a field that is likely never used (because typically, it will be obvious that a tensor is non overlapping and dense, because the tensor is contiguous.) So we take a different approach: instead of trying to trace through the logic computation of non-overlapping and dense, we instead introduce a new opaque operator IsNonOverlappingAndDenseIndicator which represents all of the compute that would have been done here. This function returns an integer 0 if `is_non_overlapping_and_dense` would have returned `False`, and an integer 1 otherwise, for technical reasons (Sympy does not easily allow defining custom functions that return booleans). The function itself only knows how to evaluate itself if all of its arguments are integers; otherwise it is left unevaluated. This means we can always guard on it (as `size_hint` will always be able to evaluate through it), but otherwise its insides are left a black box. We typically do NOT expect this custom function to show up in actual boolean expressions, because we will typically shortcut it due to the tensor being contiguous. It's possible we should apply this treatment to all of the other `compute_` operations, more investigation necessary. As a technical note, because this operator takes a pair of a list of SymInts, we need to support converting `ArrayRef<SymNode>` to Python, and I also unpack the pair of lists into a single list because I don't know if Sympy operations can actually validly take lists of Sympy expressions as inputs. See for example `_make_node_sizes_strides`
* On the Python side, we also introduce a SymBool class, and update SymNode to track bool as a valid pytype. There is some subtlety here: bool is a subclass of int, so one has to be careful about `isinstance` checks (in fact, in most cases I replaced `isinstance(x, int)` with `type(x) is int` for expressly this reason.) Additionally, unlike, C++, I do NOT define bitwise inverse on SymBool, because it does not do the correct thing when run on booleans, e.g., `~True` is `-2`. (For that matter, they don't do the right thing in C++ either, but at least in principle the compiler can warn you about it with `-Wbool-operation`, and so the rule is simple in C++; only use logical operations if the types are statically known to be SymBool). Alas, logical negation is not overrideable, so we have to introduce `sym_not` which must be used in place of `not` whenever a SymBool can turn up. To avoid confusion with `__not__` which may imply that `operators.__not__` might be acceptable to use (it isn't), our magic method is called `__sym_not__`. The other bitwise operators `&` and `|` do the right thing with booleans and are acceptable to use.
* There is some annoyance working with booleans in Sympy. Unlike int and float, booleans live in their own algebra and they support less operations than regular numbers. In particular, `sympy.expand` does not work on them. To get around this, I introduce `safe_expand` which only calls expand on operations which are known to be expandable.
TODO: this PR appears to greatly regress performance of symbolic reasoning. In particular, `python test/functorch/test_aotdispatch.py -k max_pool2d` performs really poorly with these changes. Need to investigate.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92149
Approved by: https://github.com/albanD, https://github.com/Skylion007
It turns out our old max/min implementation didn't do anything, because `__max__` and `__min__` are not actually magic methods in Python. So I give 'em the `sym_` treatment, similar to the other non-overrideable builtins.
NB: I would like to use `sym_max` when computing contiguous strides but this appears to make `python test/functorch/test_aotdispatch.py -v -k test_aot_autograd_symbolic_exhaustive_nn_functional_max_pool2d_cpu_float32` run extremely slowly. Needs investigating.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92107
Approved by: https://github.com/albanD, https://github.com/voznesenskym, https://github.com/Skylion007
As we live in C++17 world
This is a functional no-op, just
- `s/namespace at { namespace native {/namespace at::native {/`
- `s/namespace torch { namespace jit {/namespace torch::jit {/`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92100
Approved by: https://github.com/izaitsevfb
Apply clang-tidy check modernize-use-emplace. This is slightly more efficient by using an inplace constructor and is the recommended style in parts of the codebase covered by clang-tidy. This just manually applies the check to rest of the codebase. Pinging @ezyang as this is related to my other PRs he reviewed like #89000
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91077
Approved by: https://github.com/ezyang
Avoid double exception in destructor if attempting to serialize to
python object that does not have `write` method
Use `Finalizer` class in `PyTorchStreamWriter::writeEndOfFile()` to a
always set `finailized_` property even if excretion occurs. (as there
isn't much one can do at this point)
Add expicit check for the attribue to `_open_zipfile_writer_buffer` and
add unitests
Modernize code a bit by using Python-3 `super()` method
Fixes https://github.com/pytorch/pytorch/issues/87997
Pull Request resolved: https://github.com/pytorch/pytorch/pull/88128
Approved by: https://github.com/albanD
Fixes minor perf regression I saw in #85688 and replaced throughout the code base. `obj == Py_None` is directly equivalent to is_none(). Constructing a temporary py::none() object needlessly incref/decref the refcount of py::none, this method avoids that and therefore is more efficient.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/88051
Approved by: https://github.com/albanD
This refactor was prompted by challenges handling mixed int/float
operations in C++. A previous version of this patch
added overloads for each permutation of int/float and was unwieldy
https://github.com/pytorch/pytorch/pull/87722/ This PR takes a different
approach.
The general outline of the patch is to combine the C++ types SymIntNode
and SymFloatNode into a single type, SymNode. This is type erased; we
no longer know statically at C++ if we have an int/float and have to test
it with the is_int()/is_float() virtual methods. This has a number of
knock on effects.
- We no longer have C++ classes to bind to Python. Instead, we take an
entirely new approach to our Python API, where we have a SymInt/SymFloat
class defined entirely in Python, which hold a SymNode (which corresponds
to the C++ SymNode). However, SymNode is not pybind11-bound; instead,
it lives as-is in Python, and is wrapped into C++ SymNode using PythonSymNode
when it goes into C++. This implies a userland rename.
In principle, it is also possible for the canonical implementation of SymNode
to be written in C++, and then bound to Python with pybind11 (we have
this code, although it is commented out.) However, I did not implement
this as we currently have no C++ implementations of SymNode.
Because we do return SymInt/SymFloat from C++ bindings, the C++ binding
code needs to know how to find these classes. Currently, this is done
just by manually importing torch and getting the attributes.
- Because SymInt/SymFloat are easy Python wrappers, __sym_dispatch__ now
takes SymInt/SymFloat, rather than SymNode, bringing it in line with how
__torch_dispatch__ works.
Some miscellaneous improvements:
- SymInt now has a constructor that takes SymNode. Note that this
constructor is ambiguous if you pass in a subclass of SymNode,
so an explicit downcast is necessary. This means toSymFloat/toSymInt
are no more. This is a mild optimization as it means rvalue reference
works automatically.
- We uniformly use the caster for c10::SymInt/SymFloat, rather than
going the long way via the SymIntNode/SymFloatNode.
- Removed some unnecessary toSymInt/toSymFloat calls in normalize_*
functions, pretty sure this doesn't do anything.
- guard_int is now a free function, since to guard on an int you cannot
assume the method exists. A function can handle both int and SymInt
inputs.
- We clean up the magic method definition code for SymInt/SymFloat/SymNode.
ONLY the user classes (SymInt/SymFloat) get magic methods; SymNode gets
plain methods; this is to help avoid confusion between the two types.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
cc @jansel @mlazos @soumith @voznesenskym @yanboliang @penguinwu @anijain2305
Pull Request resolved: https://github.com/pytorch/pytorch/pull/87817
Approved by: https://github.com/albanD, https://github.com/anjali411
