test_fake_tensor.py

# Owner(s): ["module: meta tensors"]

import sys

from torch.testing._internal.common_utils import (
    TestCase, TEST_WITH_TORCHDYNAMO, run_tests, skipIfCrossRef, skipIfRocm, skipIfTorchDynamo, parametrize,
    instantiate_parametrized_tests, TemporaryFileName)
import torch
import torch._dynamo
import itertools
import numpy as np
from torch.testing._internal.jit_utils import RUN_CUDA
from torch._guards import tracing, TracingContext
from torch._subclasses.fake_tensor import (
    extract_tensor_metadata,
    FakeTensor,
    FakeTensorMode,
    FakeTensorConverter,
    DynamicOutputShapeException,
    UnsupportedOperatorException,
    unset_fake_temporarily,
)
from torch.fx.experimental.symbolic_shapes import ShapeEnv, DimDynamic, free_symbols, StatelessSymbolicContext, ShapeEnvSettings
from torch.testing._internal.custom_op_db import custom_op_db
from torch.testing._internal.common_device_type import ops
from torch.testing._internal.common_device_type import instantiate_device_type_tests, OpDTypes
from torch.testing._internal.common_cuda import PLATFORM_SUPPORTS_FLASH_ATTENTION
from torch.fx.passes.fake_tensor_prop import FakeTensorProp
from torch._dynamo.testing import rand_strided
from torch._C._functorch import is_batchedtensor, _add_batch_dim, get_unwrapped
from torch.testing import FileCheck
import dataclasses
import inspect
import unittest
import torch._prims as prims
import contextlib
import weakref
import copy
import pickle
import torch._functorch.config
import torch.testing._internal.optests as optests
from unittest.mock import patch

from torch import distributed as dist
from torch.utils._mode_utils import no_dispatch
from torch.utils._python_dispatch import TorchDispatchMode
import torch.utils._pytree as pytree

aten = torch.ops.aten

torch._dynamo.config.fake_tensor_cache_enabled = True
torch._dynamo.config.fake_tensor_cache_crosscheck_enabled = True

class FakeTensorTest(TestCase):
    def checkType(self, t, device_str, size):
        self.assertTrue(isinstance(t, FakeTensor))
        self.assertEqual(t.device.type, device_str)
        self.assertEqual(list(t.size()), size)


    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_cuda_initialized(self):
        # doesnt error
        with FakeTensorMode():
            p = torch.randn(4, 2, requires_grad=True, device='cuda')
            x = torch.randn(8, 4, device='cuda')
            y = torch.mm(x, p).square().sum()
            y.backward()

    def test_basic(self):
        x = torch.empty(2, 2, device="cpu")
        y = torch.empty(4, 2, 2, device="cpu")
        with FakeTensorMode() as mode:
            x = mode.from_tensor(x)
            y = mode.from_tensor(y)
            z = x + y
            self.assertEqual(z.shape, (4, 2, 2))
            self.assertEqual(z.device, torch.device("cpu"))
            self.assertTrue(isinstance(z, FakeTensor))

    def test_custom_op_fallback(self):
        from torch.library import Library, impl

        test_lib = Library("my_test_op", "DEF")  # noqa: TOR901
        test_lib.define('foo(Tensor self) -> Tensor')

        @impl(test_lib, 'foo', 'CPU')
        def foo_impl(self):
            return self.cos()

        x = torch.empty(2, 2, device="cpu")
        with self.assertRaisesRegex(UnsupportedOperatorException, "my_test_op.foo.default"):
            with FakeTensorMode(allow_fallback_kernels=True) as mode:
                x = mode.from_tensor(x)
                torch.ops.my_test_op.foo(x)

    def test_parameter_instantiation(self):
        with FakeTensorMode():
            x = torch.rand([4])
            y = torch.nn.parameter.Parameter(x)
            self.assertTrue(isinstance(y, torch.nn.Parameter))

    @unittest.skipIf(not dist.is_available(), "requires distributed")
    def test_fsdp_flat_param(self):
        from torch.distributed.fsdp._flat_param import FlatParameter
        with FakeTensorMode() as m:
            data = torch.randn(2, 2)
            param = FlatParameter(data, requires_grad=True)
        self.assertIsInstance(param, FlatParameter)
        self.assertIsInstance(param, torch.nn.Parameter)
        self.assertIsInstance(param, FakeTensor)

    def test_non_parameter_grad(self):
        mode = FakeTensorMode()
        t = torch.rand([4], requires_grad=True)
        fake_t = mode.from_tensor(t)
        self.assertEqual(fake_t.requires_grad, t.requires_grad)

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_index_cuda_with_cpu(self):
        with FakeTensorMode():
            x = torch.rand([2048], device='cuda')
            out = x[torch.zeros([36], dtype=torch.int64)]
            self.checkType(out, "cuda", [36])

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_shape_take_not_device(self):
        with FakeTensorMode():
            x = torch.empty(1, device="cpu")
            y = torch.empty(8, 8, device="cuda")
            out = x.resize_as_(y)
            self.assertEqual(out.shape, (8, 8))
            self.assertEqual(out.device.type, "cpu")
            self.assertTrue(isinstance(out, FakeTensor))

    def test_repr(self):
        with FakeTensorMode():
            x = torch.empty(2, 2, device="cpu")
            self.assertEqual(repr(x), 'FakeTensor(..., size=(2, 2))')
            x = torch.empty(2, 2, device="meta")
            self.assertEqual(repr(x), "FakeTensor(..., device='meta', size=(2, 2))")

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_zero_dim(self):
        with FakeTensorMode() as mode:
            x = torch.tensor(0.)
            y = torch.rand([4, 4], device="cuda")
            out = x + y
            self.assertEqual(out.shape, (4, 4))
            self.assertEqual(out.device, y.device)
            self.assertTrue(isinstance(out, FakeTensor))

    def test_nan_to_num(self):
        with FakeTensorMode():
            for dtype in [torch.float16, torch.float32]:
                x = torch.rand([4], dtype=dtype)
                y = torch.nan_to_num(x, nan=None)
                z = torch.nan_to_num(x, 0.0)
                self.assertEqual(dtype, y.dtype)
                self.assertEqual(dtype, z.dtype)

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_throw(self):
        x = torch.tensor(0.)  # TODO: tensor() errors
        with FakeTensorMode() as mode:
            x_conv = mode.from_tensor(x)
            y = torch.rand([4, 4], device="cuda")
            z = torch.rand([4, 4], device="cpu")
            self.assertRaises(Exception, lambda: torch.lerp(x_conv, y, z))

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_type_as(self):
        with FakeTensorMode():
            x = torch.rand([16, 1], device="cpu")
            y = torch.rand([4, 4], device="cuda")
            out = x.type_as(y)
            self.assertEqual(out.device.type, "cuda")
            self.assertTrue(isinstance(out, FakeTensor))

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_setitem(self):
        for device in ["cpu", "cuda"]:
            with FakeTensorMode():
                x = torch.rand([16, 1], device=device)
                x[..., 0] = 0

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_device_inplace_copy(self):
        with FakeTensorMode():
            x = torch.rand([8, 8], device="cpu")
            y = torch.rand([8, 8], device="cuda")
            assert x.copy_(y).device.type == "cpu"
            assert y.copy_(x).device.type == "cuda"

    def test_fake_dispatch_keys(self):
        with FakeTensorMode():
            x = torch.rand([4])
            f = FileCheck().check("CPU").check("ADInplaceOrView").check("AutogradCPU").check("AutocastCPU")
            f.run(torch._C._dispatch_key_set(x))

            with torch.inference_mode():
                x = torch.rand([4])
                y = x + x
                FileCheck().check("CPU").check("AutocastCPU").run(torch._C._dispatch_key_set(y))
                FileCheck().check_not("ADInplaceOrView").check_not("Autograd").run(torch._C._dispatch_key_set(y))

    def test_batch_tensor(self):
        x = torch.rand((3, 4, 5))
        b = _add_batch_dim(x, 0, 0)
        mode = FakeTensorMode()
        fake_b = mode.from_tensor(b)
        prims.utils.compare_tensor_meta(b, fake_b, check_strides=True)

        b1 = _add_batch_dim(x, 1, 1)
        b2 = _add_batch_dim(b1, 0, 2)
        fake_b2 = mode.from_tensor(b2)
        prims.utils.compare_tensor_meta(b2, fake_b2, check_strides=True)
        self.assertTrue(is_batchedtensor(fake_b2))
        fake_b1 = get_unwrapped(fake_b2)
        self.assertTrue(is_batchedtensor(fake_b1))
        fake_tensor = get_unwrapped(fake_b1)
        self.assertIsInstance(fake_tensor, FakeTensor)

    def test_constructor(self):
        with FakeTensorMode():
            x = torch.rand([4, 4], device="cpu")

        self.assertTrue(isinstance(x, FakeTensor))
        self.assertTrue(x.device.type == "cpu")

    def test_mode(self):
        with FakeTensorMode():
            y = torch.rand([4], device="cpu")
            out = y + y

        self.assertTrue(isinstance(out, FakeTensor))

    def test_full(self):
        # Test torch.full returns tensor with correct dtype
        with torch._subclasses.CrossRefFakeMode():
            y = torch.full((4, 4), 1)

    def check_function_with_fake(self, fn):
        out = fn()
        with torch._subclasses.FakeTensorMode():
            out_fake = fn()

        for a, b in zip(pytree.tree_leaves(out), pytree.tree_leaves(out_fake)):
            if not isinstance(a, torch.Tensor):
                self.assertTrue(not isinstance(b, torch.Tensor))
                continue

            prims.utils.compare_tensor_meta(a, b, check_strides=True)

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_non_kwarg_device(self):
        with FakeTensorMode():
            x = torch.rand([16, 1], device="cpu")
            y = x.to(torch.device("cpu"))
            self.assertIs(x, y)
            z = x.to(torch.device("cuda"))
            self.assertEqual(z.device.type, "cuda")

    def test_non_overlapping_stride_zero(self):
        def foo():
            x = torch.empty_strided([1, 3, 427, 640], (0, 1, 1920, 3))
            return x.half()

        self.check_function_with_fake(foo)

    def test_fake_mode_error(self):
        x = torch.rand([4, 4])

        with self.assertRaisesRegex(Exception, "Please convert all Tensors"):
            with FakeTensorMode():
                y = x[0]

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    def test_fake_grad_copy(self):
        x = torch.rand([4, 4], requires_grad=True)
        x.grad = torch.rand([4, 4])
        mode = FakeTensorMode()
        fake_x = mode.from_tensor(x)
        prims.utils.compare_tensor_meta(fake_x, x)
        prims.utils.compare_tensor_meta(fake_x.grad, x.grad)

        self.assertTrue(isinstance(fake_x.grad, FakeTensor))

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_index_put_error(self):
        mode = FakeTensorMode()
        for context in [contextlib.nullcontext, lambda: mode]:
            with context():
                y = torch.randn(2, 2, 3)
                x = torch.randn(2, 2, 3).to('cuda')
                with self.assertRaises(RuntimeError):
                    x[[1, 1]] = y

                with self.assertRaises(RuntimeError):
                    torch.ops.aten.index_put(x, torch.tensor([1, 1], device="cuda"), y)

                # no error
                torch.ops.aten.index_put(x, torch.tensor([1, 1], device="cuda"), torch.tensor(5.))
                torch.ops.aten.index_put_(x, torch.tensor([1, 1], device="cuda"), torch.tensor(5.))



    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_like_constructor(self):
        with FakeTensorMode():
            x = torch.rand([4, 4])
            y = torch.ones_like(x)
            self.assertTrue(isinstance(y, FakeTensor))
            self.assertEqual(y.device.type, "cpu")
            z = torch.ones_like(x, device="cuda")
            self.assertTrue(isinstance(z, FakeTensor))
            self.assertEqual(z.device.type, "cuda")

    def test_binary_op_type_promotion(self):
        with FakeTensorMode():
            x = torch.empty([2, 2], dtype=torch.float)
            y = torch.empty([2, 2], dtype=torch.int64)
            out = x / y
            self.assertEqual(out.dtype, torch.float)
            self.assertEqual(out.device.type, "cpu")

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    def test_from_numpy(self):
        with FakeTensorMode():
            x = torch.tensor(np.zeros([4, 4]))
            self.checkType(x, "cpu", [4, 4])

    def test_randperm(self):
        x = torch.randperm(10)
        y = torch.randperm(5, device="cpu")
        with FakeTensorMode():
            x1 = torch.randperm(10)
            prims.utils.compare_tensor_meta(x, x1)
            y1 = torch.randperm(5, device="cpu")
            prims.utils.compare_tensor_meta(y, y1)

    def test_print_in_fake_mode(self):
        x = torch.zeros(2)
        # does not fail
        with FakeTensorMode():
            out = str(x)
        assert "FakeTensor" not in out

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_upsample_bilinear_small_channels(self):
        out = []
        mode = FakeTensorMode()
        for i, context in enumerate([contextlib.nullcontext, lambda: mode]):
            with context():
                arg0_1 = torch.empty_strided((3, 427, 640), (1, 1920, 3), dtype=torch.float32, device='cuda')
                unsqueeze = torch.ops.aten.unsqueeze.default(arg0_1, 0)
                out.append(torch.ops.aten.upsample_bilinear2d.default(unsqueeze, [800, 1199], False))

        self.assertTrue(out[1].is_contiguous())
        self.checkMetaProps(out[0], out[1])

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_cpu_fallback(self):
        with FakeTensorMode(allow_fallback_kernels=False):
            filters = torch.randn(8, 4, 3, 3).cuda()
            inputs = torch.randn(1, 4, 5, 5).cuda()
            out = torch.nn.functional.conv2d(inputs, filters, padding=1)
            self.assertEqual(out.device.type, "cuda")
            self.assertEqual(list(out.size()), [1, 8, 5, 5])

        with FakeTensorMode(allow_fallback_kernels=True):
            # intentionally bad inputs
            filters = torch.randn(8, 20, 3, 3).cuda()
            inputs = torch.randn(1, 7, 10, 5).cuda()
            with self.assertRaises(RuntimeError):
                torch.nn.functional.conv2d(inputs, filters, padding=1)

        with FakeTensorMode(allow_fallback_kernels=True):
            filters = torch.randn(8, 4, 3, 3).cuda()
            inputs = torch.randn(1, 4, 5, 5).cuda()

            out = torch.nn.functional.conv2d(inputs, filters, padding=1)
            self.assertEqual(out.device.type, "cuda")
            self.assertEqual(list(out.size()), [1, 8, 5, 5])

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_out_multi_device(self):
        with FakeTensorMode():
            x = torch.rand([4])
            y = torch.rand([4], device="cuda")

            with self.assertRaisesRegex(Exception, "found two different devices"):
                torch.sin(x, out=y)

            with self.assertRaisesRegex(Exception, "found two different devices"):
                x.add_(y)


    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_normalize_device(self):
        with FakeTensorMode():
            x = torch.empty(1, device="cuda")
            y = torch.empty(1, device=f"cuda:{torch.cuda.current_device()}")
            out = x + y
        self.checkType(out, "cuda", [1])

    def test_recursive_invocation(self):
        mode = FakeTensorMode()
        with mode:
            x = torch.tensor(2)
            mode.in_kernel_invocation = True
            y = x + x
            self.assertTrue(mode.in_kernel_invocation)

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    @skipIfRocm
    @parametrize("allow_fallback_kernels", [False, True],
                 lambda a: 'with_fallback' if a else 'without_fallback')
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_cudnn_rnn(self, allow_fallback_kernels):
        def fn(
            a0,
            b0,
            b1,
            b2,
            b3,
            b4,
            b5,
            b6,
            b7,
            b8,
            b9,
            b10,
            b11,
            b12,
            b13,
            b14,
            b15,
            a3,
            a4,
            a5,
        ):
            a1 = [
                b0,
                b1,
                b2,
                b3,
                b4,
                b5,
                b6,
                b7,
                b8,
                b9,
                b10,
                b11,
                b12,
                b13,
                b14,
                b15,
            ]
            return torch.ops.aten._cudnn_rnn(
                a0,
                a1,
                4,
                a3,
                a4,
                a5,
                2,
                2048,
                0,
                2,
                False,
                0.0,
                False,
                True,
                [],
                None,
            )

        mode = FakeTensorMode(allow_fallback_kernels=allow_fallback_kernels)
        for i, context in enumerate([contextlib.nullcontext, lambda: mode]):
            with context():
                inps1 = [
                    torch.randn([92, 8, 2048]).cuda(),
                    torch.randn([8192, 2048]).cuda(),
                    torch.randn([8192, 2048]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([8192, 2048]).cuda(),
                    torch.randn([8192, 2048]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([8192, 4096]).cuda(),
                    torch.randn([8192, 2048]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([8192, 4096]).cuda(),
                    torch.randn([8192, 2048]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([8192]).cuda(),
                    torch.randn([167837696]).cuda(),
                    torch.randn([4, 8, 2048]).cuda(),
                    torch.randn([4, 8, 2048]).cuda(),
                ]
                inps2 = inps1
                inps2[len(inps2) - 1] = None  # argument `cx` can be None

                for inps in [inps1, inps2]:
                    out = fn(*inps)
                    self.assertIs(out[4], inps[-3])
                    for ten in out:
                        if i == 1:
                            self.assertTrue(isinstance(ten, FakeTensor))
                        self.assertEqual(ten.device.type, 'cuda')

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_cuda_lstm(self):
        # Ensure CUDA (non-cuDNN) impl succeeds with fake tensors.
        with torch.backends.cudnn.flags(enabled=False):
            fake_tensor_mode = FakeTensorMode(allow_fallback_kernels=False)
            with fake_tensor_mode:
                N = 5
                L = 4
                H_in = 2
                hidden_size = 3
                proj_size = 2
                num_layers = 2
                bidir = False
                D = 2 if bidir else 1
                H_out = proj_size if proj_size > 0 else hidden_size

                lstm = torch.nn.LSTM(input_size=H_in, hidden_size=hidden_size,
                                     num_layers=num_layers, proj_size=proj_size, batch_first=False,
                                     bias=True, bidirectional=bidir, device='cuda')

                h_0 = torch.randn((num_layers * D, N, H_out), device='cuda')
                c_0 = torch.randn((num_layers * D, N, hidden_size), device='cuda')
                inp = torch.randn((L, N, H_in), device='cuda')
                (output, (h_n, c_n)) = lstm(inp, (h_0, c_0))
                output.sum().backward()

                self.assertEqual(output.shape, (L, N, D * H_out))
                self.assertEqual(h_n.shape, (D * num_layers, N, H_out))
                self.assertEqual(c_n.shape, (D * num_layers, N, hidden_size))

    def test_data_dependent_operator(self):
        with FakeTensorMode(allow_fallback_kernels=False):
            x = torch.rand([10, 10])

            self.assertRaises(DynamicOutputShapeException, lambda: torch.nonzero(x))

    def test_tolist(self):
        shape_env = ShapeEnv()
        with FakeTensorMode(allow_fallback_kernels=False, shape_env=shape_env):
            x = torch.rand([10])
            x.tolist()

    def test_same_shape_env_preserved(self):
        shape_env = ShapeEnv()
        mode1 = FakeTensorMode(shape_env=shape_env)
        t1 = mode1.from_tensor(
            torch.randn(10),
            symbolic_context=StatelessSymbolicContext(
                dynamic_sizes=[DimDynamic.DYNAMIC],
                constraint_sizes=[None]
            )
        )
        mode2 = FakeTensorMode(shape_env=shape_env)
        t2 = mode2.from_tensor(t1)
        # t2.size(0) is still dynamic, even though we didn't pass DYNAMIC here
        self.assertIsNot(t2, t1)
        self.assertIs(t1.fake_mode, mode1)
        self.assertIs(t2.fake_mode, mode2)
        self.assertIs(t2.size(0).node.shape_env, t1.size(0).node.shape_env)
        self.assertEqual(str(t2.size(0)), str(t1.size(0)))

    def test_jagged_fake_to_fake_preserved(self):
        from torch.nested._internal.nested_tensor import jagged_from_list

        S0, S1, S2 = 3, 4, 5
        D = 4
        a = torch.randn(S0, D, requires_grad=True, dtype=torch.float64)
        b = torch.randn(S1, D, requires_grad=True, dtype=torch.float64)
        c = torch.randn(S2, D, requires_grad=True, dtype=torch.float64)
        offsets = None
        jt, _ = jagged_from_list([a, b, c], offsets)
        shape_env = ShapeEnv()
        mode1 = FakeTensorMode(shape_env=shape_env)
        t1 = mode1.from_tensor(jt)
        mode2 = FakeTensorMode(shape_env=shape_env)
        t2 = mode2.from_tensor(t1)
        # It's not obvious that the invocation above makes it dynamic but it
        # does!
        self.assertTrue(free_symbols(t1.size()))
        self.assertIsNot(t2, t1)
        self.assertIs(t1.offsets().fake_mode, mode1)
        self.assertIs(t2.offsets().fake_mode, mode2)
        self.assertIs(t2.size(1).node.shape_env, t1.size(1).node.shape_env)
        self.assertEqual(str(t2.size(1)), str(t1.size(1)))

    def checkMetaProps(self, t1, t2):
        prims.utils.compare_tensor_meta(t1, t2, check_strides=True)

    @skipIfCrossRef
    def test_deepcopy(self):
        with FakeTensorMode() as mode:
            pass
        mod = torch.nn.BatchNorm2d(10)
        with torch._subclasses.fake_tensor.FakeCopyMode(mode):
            mod_copied = copy.deepcopy(mod)

        def check_copy(mod, mod_copied):
            for name, param in itertools.chain(mod.named_parameters(), mod.named_buffers()):
                param_copied = getattr(mod_copied, name)
                self.checkMetaProps(param, param_copied)
                self.assertTrue(isinstance(param_copied, FakeTensor))
                self.assertEqual(isinstance(param, torch.nn.Parameter), isinstance(param_copied, torch.nn.Parameter))
                self.assertEqual(param.requires_grad, param_copied.requires_grad)

        check_copy(mod, mod_copied)

        class ModuleNew(torch.nn.Module):
            def __init__(self):
                super().__init__()
                self.a = torch.rand([10, 2])
                self.b = self.a
                self.c = self.a[0]

        mod = ModuleNew()
        with torch._subclasses.fake_tensor.FakeCopyMode(mode):
            mod_copied = copy.deepcopy(mod)

        self.assertIs(mod_copied.a, mod_copied.b)
        self.assertEqual(mod_copied.b.storage()._cdata, mod_copied.a.storage()._cdata)

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_new(self):
        with FakeTensorMode():
            a = torch.rand([16, 1])
            self.checkType(a.new(10, 10), "cpu", [10, 10])
            self.checkType(a.new([1, 2, 3, 4]), "cpu", [4])
            b = torch.rand([4, 4], device='cuda')
            self.checkType(b.new(device='cuda'), "cuda", [0])
            self.checkType(a.new(torch.rand([1])), "cpu", [1])

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    def test_scalar_inputs(self):
        with FakeTensorMode():
            self.checkType(torch.div(3, 2), "cpu", [])
            ten = torch.zeros(2, dtype=torch.int32) * 2.0
            self.assertEqual(ten.dtype, torch.float)
            self.checkType(ten, "cpu", [2])

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    def test_allow_meta(self):
        def run_meta():
            with FakeTensorMode():
                x = torch.rand([4], device="meta")
                return x + x

        self.checkType(run_meta(), "meta", [4])

        with patch.object(torch._functorch.config, "fake_tensor_allow_meta", False):
            self.assertRaises(Exception, run_meta)

    def test_embedding_bag_meta(self):
        def f():
            # This behavior was originally unintentional but we see people
            # relying on it
            embedding = torch.nn.EmbeddingBag(10, 3, mode='sum', device='meta')
            input = torch.tensor([1, 2, 4, 5, 4, 3, 2, 9], dtype=torch.long)
            offsets = torch.tensor([0, 4], dtype=torch.long)
            return embedding(input, offsets)

        real_out = f()
        with FakeTensorMode():
            fake_out = f()

        for r, f in zip(real_out, fake_out):
            self.assertEqual(r.size(), f.size())
            self.assertEqual(r.device, f.device)

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    def test_mixed_real_and_fake_inputs(self):
        class _TestPattern(torch.nn.Module):
            def __init__(self):
                super().__init__()
                self.conv = torch.nn.Conv2d(1, 1, 1)
                self.bn = torch.nn.BatchNorm2d(1)

            def forward(self, input):
                running_std = torch.sqrt(self.bn.running_var + self.bn.eps)
                scale_factor = self.bn.weight / running_std
                weight_shape = [1] * len(self.conv.weight.shape)
                weight_shape[0] = -1
                bias_shape = [1] * len(self.conv.weight.shape)
                bias_shape[1] = -1
                scaled_weight = self.conv.weight * scale_factor.reshape(weight_shape)
                zero_bias = torch.zeros_like(self.conv.bias, dtype=input.dtype)
                conv = self.conv._conv_forward(input, scaled_weight, zero_bias)
                conv_orig = conv / scale_factor.reshape(bias_shape)
                conv_orig = conv_orig + self.conv.bias.reshape(bias_shape)
                conv = self.bn(conv_orig)
                return conv

        example_inputs = (torch.randn(1, 1, 3, 3),)
        mod = _TestPattern()
        with FakeTensorMode(allow_non_fake_inputs=True):
            out = mod(torch.randn(1, 1, 3, 3))
        self.checkType(out, "cpu", (1, 1, 3, 3))

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_aten_copy_multi_device(self):
        with FakeTensorMode():
            x1 = torch.rand(4, device="cpu")
            x2 = torch.rand(4, device="cuda")
            copy1 = torch.ops.aten.copy.default(x1, x2)
            copy2 = torch.ops.aten.copy.default(x2, x1)
            out = torch.empty(4, device="cpu")
            torch.ops.aten.copy.out(x1, x2, out=out)
        self.checkType(copy1, "cpu", (4,))
        self.checkType(copy2, "cuda", (4,))
        self.checkType(out, "cpu", (4,))

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_aten_index_multi_device(self):
        with FakeTensorMode():
            x1 = torch.rand(4, 4, device="cpu")
            x2 = torch.rand(4, 4, device="cuda")
            i1 = torch.tensor([0, 1], device="cuda")
            i2 = torch.tensor([0, 1], device="cpu")
            r1 = torch.ops.aten.index(x1, i1)
            r2 = torch.ops.aten.index(x2, i2)

            y1 = torch.rand(4, device="cpu")
            y2 = torch.rand(4, device="cuda")
            j1 = torch.tensor([2], device="cuda")
            j2 = torch.tensor([2], device="cpu")
            r3 = torch.ops.aten.index_put.default(x1, j1, y1)
            r4 = torch.ops.aten.index_put.default(x2, j2, y2)
        self.checkType(r1, "cpu", ())
        self.checkType(r2, "cuda", ())
        self.checkType(r3, "cpu", (4, 4))
        self.checkType(r4, "cuda", (4, 4))

    @unittest.skipIf(TEST_WITH_TORCHDYNAMO, "isinstance check for FakeTensor won't work with compile")
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_aten_slice_scatter_multi_device(self):
        with FakeTensorMode():
            x1 = torch.rand(4, 4, device="cpu")
            y1 = torch.rand(2, 4, device="cuda")
            x2 = torch.rand(4, 4, device="cuda")
            y2 = torch.rand(2, 4, device="cpu")
            out = torch.empty(4, 4, device="cpu")
            r1 = torch.ops.aten.slice_scatter.default(x1, y1, start=2)
            r2 = torch.ops.aten.slice_scatter.default(x2, y2, start=2)
            r3 = torch.ops.aten.slice_scatter.out(x1, y1, out=out, start=2)
        self.checkType(r1, "cpu", (4, 4))
        self.checkType(r2, "cuda", (4, 4))
        self.checkType(r3, "cpu", (4, 4))
        self.checkType(out, "cpu", (4, 4))

    def test__adaptive_avg_pool2d_backward(self):
        with FakeTensorMode():
            grad_out = torch.rand(2, 3, 4, 4)
            inp = torch.rand(2, 3, 4, 4).to(memory_format=torch.channels_last)
            grad_in = torch.ops.aten._adaptive_avg_pool2d_backward(grad_out, inp)
            self.assertTrue(torch._prims_common.suggest_memory_format(grad_in) == torch.channels_last)

    @unittest.skipIf(
        sys.version_info >= (3, 12), "torch.compile is not supported on python 3.12+"
    )
    def test_export_numpy(self):
        class MyNumpyModel(torch.nn.Module):
            def forward(self, input):
                input = input.numpy()
                return input + np.random.randn(*input.shape)

        with FakeTensorMode():
            ep = torch.export.export(MyNumpyModel(), args=(torch.randn(1000),))
            self.assertTrue(isinstance(ep, torch.export.ExportedProgram))


class FakeTensorConstHandling(TestCase):
    def assertConst(self, *args):
        for arg in args:
            self.assertTrue(arg.constant is not None)

    def assertNotConst(self, *args):
        for arg in args:
            self.assertTrue(arg.constant is None)

    def test_simple(self):
        with FakeTensorMode():
            x = torch.tensor(4.)
            self.assertEqual(x.item(), 4.)

    def test_inplace_add(self):
        with FakeTensorMode():
            x = torch.tensor(4.)
            y = x.add_(1)
            self.assertEqual(x.item(), 5.)
            self.assertEqual(y.item(), 5.)
            self.assertConst(x, y)

    def test_shared_storages(self):
        with FakeTensorMode():
            x = torch.tensor([4.])
            y = x[:]

            self.assertEqual(x.storage()._cdata, y.storage()._cdata)
            self.assertEqual(x.constant.storage()._cdata, y.constant.storage()._cdata)

    def test_constant_invalidation(self):
        with FakeTensorMode():
            x = torch.tensor([1.])
            self.assertConst(x)
            y = torch.rand([1])
            x.add_(y)
            self.assertNotConst(x)

    def test_inplace_view_invalidation(self):
        with FakeTensorMode():
            x = torch.tensor([1])
            self.assertConst(x)
            x.resize_([2])
            self.assertEqual(x.size(0), 2)
            self.assertNotConst(x)

    def test_fake_tensor_in_intlist_repro(self):

        def fn(tensors):
            max_size = torch.tensor([800, 1216], dtype=torch.int64)
            batch_shape = [len(tensors)] + list(tensors[0].shape[:-2]) + list(max_size)
            return tensors[0].new_full(batch_shape, 0.0)

        with self.assertRaises(torch._subclasses.fake_tensor.DataDependentOutputException):
            with torch._subclasses.fake_tensor.FakeTensorMode():
                a = torch.randn(3, 800, 1199)
                b = torch.randn(3, 800, 800)
                inputs = [a, b]
                ref = fn(inputs)

    def test_fake_tensor_batch_norm_cpu(self):
        with torch._subclasses.CrossRefFakeMode():
            m = torch.nn.Sequential(
                torch.nn.BatchNorm2d(10),
                torch.nn.ReLU(),
            )
            m.eval()
            out = m(torch.randn([2, 10, 8, 8]))

    def test_shared_storage_invalidation(self):
        with FakeTensorMode():
            x = torch.tensor([1.])
            y = x[:]
            self.assertConst(x, y)
            y.add_(torch.rand([1]))
            self.assertNotConst(x, y)

    def test_aliased_const_write(self):
        with FakeTensorMode():
            x = torch.tensor([1])
            y = x.expand([4])
            self.assertNotConst(y)
            y[0] = 1
            self.assertNotConst(x)

    def test_constant_propagate_through_functions(self):
        with FakeTensorMode():
            y = torch.div(4, 4, rounding_mode='trunc')
            self.assertConst(y)

def contains_type(type: torch._C.Type, maybe_contained_type: torch._C.Type):
    return maybe_contained_type.isSubtypeOf(type) or any(
        contains_type(e, maybe_contained_type) for e in type.containedTypes()
    )


class FakeTensorOpInfoTest(TestCase):
    @ops(custom_op_db, dtypes=OpDTypes.any_one)
    def test_fake(self, device, dtype, op):
        sample_inputs_itr = op.sample_inputs(device, dtype, requires_grad=False)
        for sample_input in sample_inputs_itr:
            args = (sample_input.input,) + sample_input.args
            kwargs = sample_input.kwargs
            optests.fake_check(op, args, kwargs)


class FakeTensorConverterTest(TestCase):
    def test_memoized_conversion_to_meta(self):
        x = torch.rand(2, 2, 2)
        mode = FakeTensorMode()
        self.assertTrue(mode.from_tensor(x) is mode.from_tensor(x))

    def test_memoized_conversion_from_meta(self):
        x = torch.rand(2, 2).to(device="meta")
        mode = FakeTensorMode()
        converter = mode.fake_tensor_converter
        self.assertTrue(converter.from_meta_and_device(mode, x, "cpu") is converter.from_meta_and_device(mode, x, "cpu"))

    def test_separate_tensor_storages_view(self):
        x = torch.rand(2, 2, 2)
        y = x[0]
        mode = FakeTensorMode()
        converter = mode.fake_tensor_converter
        x_conv = converter.from_real_tensor(mode, x)
        y_conv = converter.from_real_tensor(mode, y)
        self.assertEqual(torch._C._storage_id(x_conv), torch._C._storage_id(y_conv))

    @skipIfTorchDynamo("https://github.com/pytorch/torchdynamo/issues/1991")
    def test_separate_tensor_storages_non_view(self):
        x = torch.rand(2, 2, 2)
        y = torch.rand(4, 2)
        y.set_(x.storage())
        mode = FakeTensorMode()
        converter = mode.fake_tensor_converter
        x_conv = converter.from_real_tensor(mode, x)
        y_conv = converter.from_real_tensor(mode, y)
        stor_id = torch._C._storage_id(x_conv)
        self.assertEqual(stor_id, torch._C._storage_id(y_conv))
        del x
        del x_conv
        self.assertEqual(len(converter.tensor_memo), 1)
        self.assertEqual(len(converter.meta_converter.storage_memo), 1)
        del y
        del y_conv
        self.assertEqual(len(converter.tensor_memo), 0)
        self.assertEqual(len(converter.meta_converter.storage_memo), 0)


    @skipIfTorchDynamo("https://github.com/pytorch/torchdynamo/issues/1991")
    def test_dead_weak_ref(self):
        x = torch.rand(2, 2, 2)
        y = x[0]
        mode = FakeTensorMode()
        converter = FakeTensorConverter()
        x_conv = converter.from_real_tensor(mode, x)
        x_conv_storage = x_conv.untyped_storage()
        del x_conv
        self.assertFalse(x in converter.tensor_memo)
        y_conv = converter.from_real_tensor(mode, y)
        self.assertIs(x_conv_storage, y_conv.untyped_storage())

    @skipIfTorchDynamo("https://github.com/pytorch/torchdynamo/issues/1991")
    def test_dead_key(self):
        x = torch.rand(2, 2, 2)
        mode = FakeTensorMode()
        converter = FakeTensorConverter()
        x_conv = converter.from_real_tensor(mode, x)
        self.assertEqual(len(converter.tensor_memo), 1)
        x_conv2 = converter.from_real_tensor(mode, x)
        assert x_conv2 is x_conv
        del x
        del x_conv
        del x_conv2
        self.assertEqual(len(converter.tensor_memo), 0)

    def test_no_active_mode(self):
        with FakeTensorMode() as mode:
            x = torch.empty(2, 2, device="cpu")
            y = torch.empty(2, 2, device="cpu")

        out = x + y
        self.assertEqual(mode, out.fake_mode)
        self.assertTrue(isinstance(out, FakeTensor))
        self.assertEqual(out.device.type, "cpu")

    def test_multiple_modes(self):
        t = torch.rand([4])
        t2 = torch.rand([4])
        with FakeTensorMode() as m:
            with FakeTensorMode() as m2:
                t_fake = m.from_tensor(t)
                t2_fake = m2.from_tensor(t2)

                with self.assertRaisesRegex(Exception, "Mixing fake modes"):
                    t_fake + t2_fake

    def test_separate_mode_error(self):
        with FakeTensorMode():
            x = torch.empty(2, 2, device="cpu")
        with FakeTensorMode():
            y = torch.empty(2, 2, device="cpu")
        self.assertRaises(Exception, lambda: x, y)

    @skipIfTorchDynamo("https://github.com/pytorch/torchdynamo/issues/1991")
    def test_no_ref_cycle(self):
        x = torch.rand([4])
        mode = FakeTensorMode()
        y = mode.from_tensor(x)
        self.assertEqual(len(mode.fake_tensor_converter.tensor_memo), 1)
        mode_weak = weakref.ref(mode)
        y_weak = weakref.ref(mode)
        del mode
        del y
        assert mode_weak() is None
        assert y_weak() is None


class FakeTensorOperatorInvariants(TestCase):
    @staticmethod
    def get_aten_op(schema):
        namespace, name = schema.name.split("::")
        overload = schema.overload_name if schema.overload_name else "default"
        assert namespace == "aten"
        return getattr(getattr(torch.ops.aten, name), overload)

    @staticmethod
    def get_all_aten_schemas():
        for schema in torch._C._jit_get_all_schemas():
            namespace = schema.name.split("::")[0]
            if namespace != "aten":
                continue
            yield schema

    def test_non_kwarg_only_device(self):
        for schema in self.get_all_aten_schemas():
            ten_type = torch._C.TensorType.get()
            if not any(
                contains_type(arg.type, ten_type)
                for arg in itertools.chain(schema.arguments, schema.returns)
            ):
                continue

            opt_device = torch._C.OptionalType(torch._C.DeviceObjType.get())
            has_non_kwarg_device = any(
                not arg.kwarg_only and arg.type.isSubtypeOf(opt_device)
                for arg in schema.arguments
            )
            if has_non_kwarg_device:
                self.assertTrue(
                    self.get_aten_op(schema) in torch._subclasses.fake_tensor._device_not_kwarg_ops
                )

    def test_tensor_constructors_all_have_kwarg_device(self):
        for schema in self.get_all_aten_schemas():
            op = self.get_aten_op(schema)
            if not torch._subclasses.fake_tensor._is_tensor_constructor(op):
                continue

            opt_device = torch._C.OptionalType(torch._C.DeviceObjType.get())
            has_kwarg_device = any(
                arg.kwarg_only and arg.type.isSubtypeOf(opt_device)
                for arg in schema.arguments
            )

            self.assertTrue(
                has_kwarg_device or op == torch.ops.aten._list_to_tensor.default
            )

    @unittest.expectedFailure
    def test_sparse_new(self):
        with FakeTensorMode():
            indices = torch.randn(1, 1, dtype=torch.int64)
            values = torch.randn(1)
            extra = (2,)
            sparse = torch.randn(1).to_sparse()
            # This used to segfault, now it does not, but it still raises an
            # error
            sparse2 = sparse.new(indices, values, extra)

    def test_tensor_new(self):
        with FakeTensorMode():
            x = torch.Tensor([1, 2, 3])
        self.assertIsInstance(x, FakeTensor)

    def test_like_ops(self):
        for schema in self.get_all_aten_schemas():
            if "_like" == schema.name[-5:]:
                op = self.get_aten_op(schema)
                self.assertIn(op, torch._subclasses.fake_tensor._like_tensor_constructors)

    def test_str_storage(self):
        x = torch.zeros(3)
        with FakeTensorMode() as m:
            y = m.from_tensor(x)
            self.assertExpectedInline(str(x.storage()), '''\
 0.0
 0.0
 0.0
[torch.storage.TypedStorage(dtype=torch.float32, device=cpu) of size 3]''')
            self.assertExpectedInline(str(y.storage()), '''\
...
[torch.storage.TypedStorage(dtype=torch.float32, device=meta) of size 3]''')

        self.assertExpectedInline(str(y.storage()), '''\
...
[torch.storage.TypedStorage(dtype=torch.float32, device=meta) of size 3]''')

    # at::_embedding_bag has no op info,
    # and returns extra tensors that at::embedding bag throws away
    def test_embedding_bag_private(self):
        args = [
            torch.ones(6, 1),
            torch.ones(6, dtype=torch.int64),
            torch.arange(2, dtype=torch.int64),
            False,
            2,  # mode = max
        ]

        ref_out = torch.ops.aten._embedding_bag(*args)
        with FakeTensorMode() as m:
            meta_args = [m.from_tensor(a) if isinstance(a, torch.Tensor) else a for a in args]
            meta_out = torch.ops.aten._embedding_bag(*meta_args)

        self.assertEqual(len(ref_out), len(meta_out))
        for ref_o, meta_o in zip(ref_out, meta_out):
            self.assertEqual(ref_o.size(), meta_o.size())

    def test_cross_entropy_loss(self):
        inp = torch.randn(3, 5)
        target = torch.randint(5, (3,), dtype=torch.long)
        weight = torch.rand(5)
        fn = torch.nn.functional.cross_entropy
        for w in (weight, None):
            args = (inp, target, w)
            ref = fn(*args)
            with FakeTensorMode() as m:
                meta_args = [m.from_tensor(a) if isinstance(a, torch.Tensor) else a for a in args]
                meta_out = torch.nn.functional.cross_entropy(*meta_args, label_smoothing=0.5)

            self.assertEqual(ref.size(), meta_out.size())

    @skipIfRocm
    @unittest.skipIf(not PLATFORM_SUPPORTS_FLASH_ATTENTION, "Does not support SDPA or pre-SM80 hardware")
    def test_flash_attention(self):
        class Repro(torch.nn.Module):
            def __init__(self):
                super().__init__()

            def forward(self, arg1, arg2, arg3):
                torch.ops.aten._scaled_dot_product_flash_attention(arg1, arg2, arg3, scale=0.17677669529663687)

        args_new = [
            [
                ((1, 48, 64, 64), (0, 4096, 64, 1), torch.float16, "cuda"),
                ((1, 48, 64, 64), (0, 4096, 64, 1), torch.float16, "cuda"),
                ((1, 48, 64, 64), (0, 4096, 64, 1), torch.float16, "cuda"),
            ],
            [
                ((4, 2, 16, 32), (1024, 512, 32, 1), torch.float16, "cuda"),
                ((4, 2, 16, 32), (1024, 512, 32, 1), torch.float16, "cuda"),
                ((4, 2, 16, 32), (1024, 512, 32, 1), torch.float16, "cuda"),
            ]
        ]
        for args_list in args_new:
            args = [rand_strided(bsz, num_heads, seq_len, head_dim) for
                    (bsz, num_heads, seq_len, head_dim) in args_list]
            try:
                with torch._subclasses.CrossRefFakeMode():
                    Repro()(*args)
            except RuntimeError as e:
                # We expect the cross ref to succed for the first output to fail
                # for the rng state, see Note [Seed and Offset]
                self.assertTrue("output[0]" not in str(e))
                self.assertTrue("found mismatched tensor metadata for output[6]: Devices cpu and cuda:0 are not equal!" in str(e))

    # IMPORTANT!!! Always run even if CUDA is not available
    def test_fake_cuda_no_init(self):
        with FakeTensorMode():
            torch.empty(10, device='cuda')
            torch.ones(10, device='cuda')
            torch.zeros(10, device='cuda')
            torch.rand(10, device='cuda')

    @skipIfRocm
    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_conv_c1_backward(self):
        class Repro(torch.nn.Module):
            def __init__(self):
                super().__init__()

            def forward(self, arg1, arg2, arg3):
                torch.ops.aten.convolution_backward.default(
                    arg1,
                    arg2,
                    arg3,
                    [1],
                    [1, 1],
                    [1, 1],
                    [1, 1],
                    False,
                    [0, 0],
                    1,
                    [True, True, False],
                )

        args_new = [
            ((16, 1, 128, 128), (16384, 16384, 128, 1), torch.float16, "cuda"),
            ((16, 64, 128, 128), (1048576, 1, 8192, 64), torch.float16, "cuda"),
            ((1, 64, 3, 3), (576, 9, 3, 1), torch.float16, "cuda"),
        ]
        args = [rand_strided(sh, st, dt, dev) for (sh, st, dt, dev) in args_new]

        with torch._subclasses.CrossRefFakeMode():
            Repro()(*args)

    def test_no_dispatch_with_like_function(self):
        class CountingMode(TorchDispatchMode):
            def __init__(self):
                self.count = 0

            def __torch_dispatch__(self, func, types, args=(), kwargs=None):
                self.count += 1
                return func(*args, **kwargs)

        with FakeTensorMode():
            x = torch.randn(2)
            with CountingMode() as mode:
                with no_dispatch():
                    torch.zeros_like(x)

        self.assertEqual(mode.count, 0)


class FakeTensorPropTest(TestCase):
    def test_fake_tensor_prop_on_nn_module(self):
        class ToyNnModuleWithParameters(torch.nn.Module):
            def __init__(self):
                super().__init__()
                self.layer1 = torch.nn.Linear(4, 3)
                self.layer2 = torch.nn.Linear(3, 2)

            def forward(self, value):
                value = self.layer1(value)
                value = torch.relu(value)
                value = self.layer2(value)
                return value

        model = ToyNnModuleWithParameters()
        value = torch.randn(5, 4)
        # Convert nn.Module to GraphModule so that FakeTensorProp runs.
        graph_model = torch.fx.symbolic_trace(model, (value,))
        # The following block runs FakeTensorProp on graph_module w/to the same FakeTensorMode
        #
        # TODO(wschin): there should be an API to run FakeTensorProp for GraphModule
        # with parameters and buffers.
        with FakeTensorMode() as fake_tensor_mode:

            def to_fake_tensor(x):
                if isinstance(x, torch.Tensor) and not isinstance(x, FakeTensor):
                    return fake_tensor_mode.from_tensor(x)
                return x

            fake_parameters_and_buffers = {
                k: to_fake_tensor(v)
                for k, v in itertools.chain(
                    graph_model.named_parameters(), graph_model.named_buffers()
                )
            }
            with torch.nn.utils.stateless._reparametrize_module(
                graph_model, fake_parameters_and_buffers
            ):
                # This case uses the **same** fake tensor mode to
                #  1. create fake parameters and fake buffers, and
                #  2. run FakeTensorProp
                # The result should be correct.
                result = FakeTensorProp(graph_model, fake_tensor_mode).propagate(value)
                self.assertTrue(isinstance(result, FakeTensor))
                self.assertEqual(result.shape, (5, 2))
                # This case uses the **different** fake tensor modes to
                #  1. create fake parameters and fake buffers, and
                #  2. run FakeTensorProp
                # The following code should fail.
                failed = False
                try:
                    FakeTensorProp(graph_model).propagate(value)
                except AssertionError:
                    # AssertionError: tensor's device must be `meta`, got cpu instead
                    failed = True
                self.assertTrue(failed)


    def test_fake_tensor_prop_on_nn_module_with_optional_args(self):
        class OptionalArgumentInBetween(torch.nn.Module):
            def __init__(self):
                super().__init__()
                self.layer1 = torch.nn.Linear(4, 3)
                self.layer2 = torch.nn.Linear(3, 2)

            def forward(self, value, another_value=None, another_optional_value=None):
                # Mimic huggingface's `forward` methods which have several optional arguments.
                # For example, GPT accepts forward(self, input_ids, None, attention_mask, ...).
                # To apply FakeTensorProp, its from_real_tensor(...) needs to accept None.
                if another_value is None:
                    another_value = torch.rand_like(value)
                if another_optional_value is None:
                    another_optional_value = torch.rand_like(value)
                value = value + another_value + another_optional_value
                return value * value

        fake_mode = FakeTensorMode(allow_non_fake_inputs=True, allow_fallback_kernels=False)
        with fake_mode:
            model = OptionalArgumentInBetween()
            value = torch.randn(5, 4)
            another_optional_value = torch.randn(5, 4)
            graph_model = torch.fx.symbolic_trace(model, (value, None, another_optional_value))
            FakeTensorProp(graph_model, fake_mode).propagate(value, None, another_optional_value)


    def test_torch_load_with_fake_mode(self):

        class TheModelClass(torch.nn.Module):
            def __init__(self):
                super().__init__()
                self.fc1 = torch.nn.Linear(5, 10)

            def forward(self, x):
                return self.fc1(x)

        with TemporaryFileName() as state_dict_file:
            # Create state_dict to be loaded later
            model = TheModelClass()
            torch.save(model.state_dict(), state_dict_file)

            fake_mode = FakeTensorMode()
            with fake_mode:
                torch.load(state_dict_file)  # scenario 1
                torch.load(state_dict_file, map_location="cpu")  # scenario 2


class FakeTensorSerialization(TestCase):
    def test_serialization(self):
        x = torch.tensor([0], device="cpu")
        with FakeTensorMode():
            y = pickle.loads(pickle.dumps(x))
            self.assertEqual(type(y), FakeTensor)
            self.assertEqual(y.device.type, "meta")

            with unset_fake_temporarily():
                y = pickle.loads(pickle.dumps(x))
                self.assertEqual(x.device, y.device)

    def test_serialization_with_tracing(self):
        x = torch.tensor([0], device="cpu")
        with tracing(TracingContext(FakeTensorMode())):
            y = pickle.loads(pickle.dumps(x))
            self.assertEqual(x.device, y.device)


class FakeTensorDispatchCache(TestCase):
    def test_shape_env_settings(self):
        """
        Validation that any boolean settings in ShapeEnv are present in the
        ShapeEnvSettings. We hope to ensure that any new settings that might
        affect FakeTensor dispatch are included in the cache key calculation.
        If this test fails, consider updating ShapeEnvSettings or change this
        test to omit checking for the new field.
        """
        init_sig = inspect.signature(ShapeEnv._init)
        args = [
            name for name, param in init_sig.parameters.items()
            if type(param.default) is bool
        ]

        settings = [f.name for f in dataclasses.fields(ShapeEnvSettings)]
        for arg in args:
            self.assertTrue(arg in settings)

    def _test_cache_key(self, fm, x, y, z):
        """
        Helper for all test_cache_key_* tests below. Assert that the
        cache keys for inputs x and y are the same, but z is different.
        """
        func = aten.add.Tensor
        key_x = fm._cache_key(func, [x], {})
        key_y = fm._cache_key(func, [y], {})
        key_z = fm._cache_key(func, [z], {})

        self.assertEqual(key_x, key_y)
        self.assertNotEqual(key_x, key_z)

    def test_cache_key_dtype(self):
        with FakeTensorMode() as fm:
            x = torch.randn(4, 3, dtype=torch.float16)
            y = torch.randn(4, 3, dtype=torch.float16)
            z = x.to(dtype=torch.float32)
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_shape(self):
        with FakeTensorMode() as fm:
            x = torch.randn(4, 3)
            y = torch.randn(4, 3)
            z = torch.randn(4, 2)
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_stride(self):
        with FakeTensorMode() as fm:
            x = torch.randn(4, 2)
            y = torch.randn(4, 2)
            z = x.as_strided((4, 2), (1, 2))
            self._test_cache_key(fm, x, y, z)

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_cache_key_device(self):
        with FakeTensorMode() as fm:
            x = torch.randn(4, 3)
            y = torch.randn(4, 3)
            z = x.to(device="cuda")
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_memory_format(self):
        with FakeTensorMode() as fm:
            x = torch.randn(1, 2, 3, 4)
            y = torch.randn(1, 2, 3, 4)
            z = x.to(memory_format=torch.channels_last)
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_storage_offset(self):
        with FakeTensorMode() as fm:
            x = torch.randn(3)[1:]
            y = torch.randn(3)[1:]
            z = torch.randn(2)
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_requires_grad(self):
        with FakeTensorMode() as fm:
            x = torch.randn(4, 3)
            y = torch.randn(4, 3)
            z = torch.randn(4, 3, requires_grad=True)
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_is_conj(self):
        with FakeTensorMode() as fm:
            x = torch.randn(4, 3, dtype=torch.complex64)
            y = torch.randn(4, 3, dtype=torch.complex64)
            z = torch.randn(4, 3, dtype=torch.complex64)
            torch._C._set_conj(z, not z.is_conj())
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_is_neg(self):
        with FakeTensorMode() as fm:
            x = torch.randn(4, 3, dtype=torch.complex64)
            y = torch.randn(4, 3, dtype=torch.complex64)
            z = torch.randn(4, 3, dtype=torch.complex64)
            torch._C._set_neg(z, not z.is_neg())
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_is_inference(self):
        with torch.inference_mode(True):
            t = torch.randn(4, 3)
        with FakeTensorMode() as fm:
            x = torch.randn(4, 3)
            y = torch.randn(4, 3)
            z = fm.from_tensor(t)
            self._test_cache_key(fm, x, y, z)

    def test_cache_key_constants(self):
        with FakeTensorMode() as fm:
            # Python hashes 1.0 to the same value as 1. Make sure the
            # cache key calculation differentiates them.
            self._test_cache_key(fm, 1.0, 1.0, 1)
            self._test_cache_key(fm, 0.0, 0.0, 0)

    def assertHitsMisses(self, hits, misses):
        """
        Helper to assert on the number of recorded hits and misses.
        """
        info = FakeTensorMode.cache_info()
        self.assertEqual(info.hits, hits)
        self.assertEqual(info.misses, misses)

    def assertBypasses(self, reason, count):
        """
        Helper to assert on the number of recorded bypasses.
        """
        info = FakeTensorMode.cache_info()
        if count > 0:
            self.assertIn(reason, info.bypasses)
            self.assertEqual(info.bypasses[reason], count)
        else:
            self.assertNotIn(reason, info.bypasses)

    def test_cache_hit(self):
        """
        Test that cache hit/miss counters are updated correctly.
        """
        with FakeTensorMode():
            x = torch.randn(4, 3)
            y = torch.randn(4, 3)

            FakeTensorMode.cache_clear()
            self.assertHitsMisses(0, 0)
            res1 = x + y
            self.assertHitsMisses(0, 1)
            res2 = x + y
            self.assertHitsMisses(1, 1)

            self.assertEqual(
                extract_tensor_metadata(res1),
                extract_tensor_metadata(res2),
            )

    def test_cache_bypass(self):
        """
        Test that cache bypass counters are updated correctly.
        """
        with FakeTensorMode():
            x = torch.randn(1, 2)

            FakeTensorMode.cache_clear()
            self.assertBypasses("inplace view", 0)

            x.unsqueeze_(0)
            self.assertBypasses("inplace view", 1)

    def test_cache_default_dtype(self):
        """
        Test that the default dtype is respected when serving cached results.
        """
        with FakeTensorMode():
            x = torch.tensor([1, 2], dtype=torch.int32)
            torch.set_default_dtype(torch.float32)

            FakeTensorMode.cache_clear()
            self.assertHitsMisses(0, 0)

            y = x + 1.0
            self.assertEqual(y.dtype, torch.float32)
            self.assertHitsMisses(0, 1)

            torch.set_default_dtype(torch.float16)
            y = x + 1.0
            self.assertEqual(y.dtype, torch.float16)
            self.assertHitsMisses(0, 2)

            torch.set_default_dtype(torch.float32)
            y = x + 1.0
            self.assertEqual(y.dtype, torch.float32)
            self.assertHitsMisses(1, 2)

    @unittest.skipIf(not RUN_CUDA, "requires cuda")
    def test_cache_default_device(self):
        """
        Test that the default device is respected when serving cached results.
        """
        with FakeTensorMode():
            FakeTensorMode.cache_clear()
            self.assertHitsMisses(0, 0)

            torch.set_default_device("cpu")
            x = torch.tensor([1, 2])
            y = x + 1.0
            self.assertEqual(y.device.type, "cpu")
            self.assertHitsMisses(0, 1)

            torch.set_default_device("cuda")
            x = torch.tensor([1, 2])
            y = x + 1.0
            self.assertEqual(y.device.type, "cuda")
            self.assertHitsMisses(0, 2)

            torch.set_default_device("cpu")
            x = torch.tensor([1, 2])
            y = x + 1.0
            self.assertEqual(y.device.type, "cpu")
            self.assertHitsMisses(1, 2)

    def test_cache_inplace_op(self):
        """
        Test that inplace ops served from the cache correctly reference the
        input parameter.
        """
        with FakeTensorMode():
            x = torch.randn(1, 2)
            y = torch.randn(1, 2)

            FakeTensorMode.cache_clear()
            self.assertHitsMisses(0, 0)

            z = x.add_(y)
            self.assertHitsMisses(0, 1)
            self.assertEqual(id(x), id(z))

            w = x.add_(y)
            self.assertHitsMisses(1, 1)
            self.assertEqual(id(x), id(w))

    def test_cache_view_op(self):
        """
        Test that view ops are handled correctly when served from the cache.
        """
        with FakeTensorMode():
            x1 = torch.ones(2, requires_grad=True).clone()
            x2 = torch.ones(2, requires_grad=True).clone()
            y2 = x2.view(-1)

            # Test operating on a non-view tensor, then the same operation
            # on a view tensor. Assert that the view property is set correctly.
            z1 = x1.mul_(2)
            self.assertFalse(z1._is_view())

            z2 = y2.mul_(2)
            self.assertTrue(z2._is_view())

            # Now the other way around: first operate on a view tensor, then
            # the same operation on a non-view tensor.
            z2 = y2.mul_(2)
            self.assertTrue(z2._is_view())

            z1 = x1.mul_(2)
            self.assertFalse(z1._is_view())

    def test_cache_dispatch_key_set(self):
        """
        Test that operations that change the dispatch key set bypass caching.
        """
        with FakeTensorMode():
            FakeTensorMode.cache_clear()
            self.assertBypasses("dispatch_key_set mismatch", 0)

            x = torch._efficientzerotensor(3)
            self.assertTrue(x._is_zerotensor())
            self.assertBypasses("dispatch_key_set mismatch", 1)

            y = torch._efficientzerotensor(3)
            self.assertTrue(y._is_zerotensor())
            self.assertBypasses("dispatch_key_set mismatch", 2)

    def test_inference_mode(self):
        """
        Test that caching handles inference mode correctly.
        """
        with FakeTensorMode():
            x = torch.randn(4, 3)
            y = torch.randn(4, 3)

            FakeTensorMode.cache_clear()
            self.assertHitsMisses(0, 0)

            # Expect a miss when the inference mode is different
            res1 = x + y
            with torch.inference_mode():
                res2 = x + y

            self.assertHitsMisses(0, 2)
            self.assertFalse(res1.is_inference())
            self.assertTrue(res2.is_inference())

            # Second tries should see hits
            res3 = x + y

            self.assertHitsMisses(1, 2)
            self.assertFalse(res3.is_inference())
            self.assertEqual(
                extract_tensor_metadata(res1),
                extract_tensor_metadata(res3),
            )

            with torch.inference_mode():
                res4 = x + y

            self.assertHitsMisses(2, 2)
            self.assertTrue(res4.is_inference())
            self.assertEqual(
                extract_tensor_metadata(res2),
                extract_tensor_metadata(res4),
            )


instantiate_parametrized_tests(FakeTensorTest)

only_for = ("cpu", "cuda")
instantiate_device_type_tests(FakeTensorOpInfoTest, globals(), only_for=only_for)

if __name__ == "__main__":
    run_tests()