pytorch/docs
Henry Tsang 350bc2a166 [export] Add support for symbool to make it usable for torch.cond (#138765)
# Why?

I want the following code to work.

minimal repro:
```
class M(torch.nn.Module):
    def forward(self, dilate_flag):
        return dilate_flag.item()

input1 = (torch.tensor([1], dtype=torch.bool, device="cuda"),)
model = M().cuda()

ep = torch.export.export(model, input1, strict=True)
path = torch._inductor.aot_compile(ep.module(), input1)
aot_model = torch._export.aot_load(path, device="cuda")
actual_output = aot_model(*input1)
```

error: AssertionError: Encountered an unsupported object of type <class 'torch.SymBool'> while writing the metadata for exported program

second error will be handled by https://github.com/pytorch/pytorch/pull/138760

# Motivation

I could technically bypass it with a torch.int tensor. However, it doesn't work with torch.cond. I want the following to work. It would also require https://github.com/pytorch/pytorch/pull/138760 for aot compile to work.

```
class M(torch.nn.Module):
    def __init__(self) -> None:
        super().__init__()
        self.dilate_flag = 0

    def forward(self, dilate_flag):
        self.dilate_flag = dilate_flag.item()

        def true_fn(dilate_flag):
            return dilate_flag.clone()

        def false_fn(dilate_flag):
            return dilate_flag.clone()

        torch.cond(
            self.dilate_flag,
            true_fn,
            false_fn,
            (dilate_flag,),
        )
        return self.dilate_flag

input1 = (torch.tensor([1], dtype=torch.bool, device="cuda"),)
input2 = (torch.tensor([0], dtype=torch.bool, device="cuda"),)
inputs = (input1, input2)
model = M().cuda()

for input in inputs:
    expected_output = model(*input)

    ep = torch.export.export(model, input, strict=False)
    path = torch._inductor.aot_compile(ep.module(), input)
    aot_model = torch._export.aot_load(path, device="cuda")
    actual_output = aot_model(*input)

    assert (
        expected_output == actual_output
    ), f"henry they are not equal {expected_output} != {actual_output}"
```

Differential Revision: D64867504

Pull Request resolved: https://github.com/pytorch/pytorch/pull/138765
Approved by: https://github.com/ydwu4
2024-11-04 23:31:49 +00:00
..
cpp Update copyrights to 2024 (#138638) 2024-10-22 21:00:58 +00:00
source [export] Add support for symbool to make it usable for torch.cond (#138765) 2024-11-04 23:31:49 +00:00
.gitignore
libtorch.rst Add ROCm documentation to libtorch (C++) reST. (#136378) 2024-09-25 02:30:56 +00:00
make.bat
Makefile
README.md
requirements.txt

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