initial check in

apex/normalization/__init__.py

@@ -1 +1,2 @@
 from .fused_layer_norm import FusedLayerNorm, MixedFusedLayerNorm, FusedRMSNorm, MixedFusedRMSNorm
+from .instance_norm import InstanceNorm3dNVFuser

apex/normalization/instance_norm.py

@@ -0,0 +1,149 @@
+import importlib
+
+import torch
+from torch import Tensor
+from torch.nn.modules.batchnorm import _NormBase
+
+global instance_norm_nvfuser_cuda
+instance_norm_nvfuser_cuda = None
+
+class InstanceNormNVFuserFunction(torch.autograd.Function):
+    @staticmethod
+    def forward(ctx, input, weight, bias, running_mean, running_var,
+                use_input_stats, momentum, eps):
+        global instance_norm_nvfuser_cuda
+        if instance_norm_nvfuser_cuda is None:
+            instance_norm_nvfuser_cuda = importlib.import_module("instance_norm_nvfuser_cuda")
+
+        channels_last = input.is_contiguous(memory_format=torch.channels_last) or input.is_contiguous(memory_format=torch.channels_last_3d)
+        if channels_last:
+            order = [0] + [i for i in range(2, len(input.shape))] + [1]
+            _input = input.permute(order)
+        else:
+            _input = input
+        assert _input.is_contiguous()
+        result = instance_norm_nvfuser_cuda.forward(_input, weight, bias, running_mean, running_var,
+                                                    use_input_stats, momentum, eps, channels_last)
+        if len(result) == 3:
+            out, mean, invstd = result
+        else:
+            running_mean, running_var, out, mean, invstd = result
+        ctx.use_input_stats = use_input_stats
+        ctx.eps = eps
+        ctx.channels_last = channels_last
+        # saving for backward in "explicit channels-last format"
+        ctx.save_for_backward(_input, weight, running_mean, running_var, mean, invstd)
+        if channels_last:
+            order = [0, len(_input.shape) - 1] + [i for i in range(1, len(_input.shape) - 1)]
+            out = out.permute(order)
+            if len(out.shape) == 4:
+                assert out.is_contiguous(memory_format=torch.channels_last)
+                assert input.is_contiguous(memory_format=torch.channels_last)
+            elif len(out.shape) == 5:
+                assert out.is_contiguous(memory_format=torch.channels_last_3d)
+                assert input.is_contiguous(memory_format=torch.channels_last_3d)
+            else:
+                assert False, "unhandled channels_last format variation in forward"
+        return out
+
+    @staticmethod
+    def backward(ctx, grad_output):
+        global instance_norm_nvfuser_cuda
+        if instance_norm_nvfuser_cuda is None:
+            instance_norm_nvfuser_cuda = importlib.import_module("instance_norm_nvfuser_cuda")
+
+        if ctx.channels_last:
+            order = [0] + [i for i in range(2, len(grad_output.shape))] + [1]
+            grad_output = grad_output.permute(order)
+        # input was saved in "explicit channels-last format"
+        assert ctx.saved_tensors[0].is_contiguous()
+        grad_output = grad_output.contiguous()
+        saved = list(ctx.saved_tensors)
+        saved.insert(1, grad_output)
+        running_mean = saved[3]
+        running_var = saved[4]
+        mean = saved[-2]
+        var = saved[-1]
+        grad_input, grad_weight, grad_bias = instance_norm_nvfuser_cuda.backward(*saved, ctx.use_input_stats, ctx.eps, ctx.channels_last)
+        if ctx.channels_last:
+            order = [0, len(grad_input.shape) - 1] + [i for i in range(1, len(grad_input.shape) - 1)]
+            grad_input = grad_input.permute(order)
+            if len(grad_input.shape) == 4:
+                assert grad_input.is_contiguous(memory_format=torch.channels_last)
+            elif len(grad_input.shape) == 5:
+                assert grad_input.is_contiguous(memory_format=torch.channels_last_3d)
+            else:
+                assert False, "unhandled channels_last format variation in backward"
+        return grad_input, grad_weight, grad_bias, None, None, None, None, None, None  
+
+
+class _InstanceNormNVFuser(_NormBase):
+    def __init__(
+        self,
+        num_features: int,
+        eps: float = 1e-5,
+        momentum: float = 0.1,
+        affine: bool = False,
+        track_running_stats: bool = False,
+        device=None,
+        dtype=None
+    ) -> None:
+        factory_kwargs = {'device': device, 'dtype': dtype}
+        super(_InstanceNormNVFuser, self).__init__(
+            num_features, eps, momentum, affine, track_running_stats, **factory_kwargs)
+        self.dummy = torch.empty([], device='cuda')
+
+    def _check_input_dim(self, input):
+        raise NotImplementedError
+
+    def _load_from_state_dict(self, state_dict, prefix, local_metadata, strict,
+                              missing_keys, unexpected_keys, error_msgs):
+        version = local_metadata.get('version', None)
+        # at version 1: removed running_mean and running_var when
+        # track_running_stats=False (default)
+        if version is None and not self.track_running_stats:
+            running_stats_keys = []
+            for name in ('running_mean', 'running_var'):
+                key = prefix + name
+                if key in state_dict:
+                    running_stats_keys.append(key)
+            if len(running_stats_keys) > 0:
+                error_msgs.append(
+                    'Unexpected running stats buffer(s) {names} for {klass} '
+                    'with track_running_stats=False. If state_dict is a '
+                    'checkpoint saved before 0.4.0, this may be expected '
+                    'because {klass} does not track running stats by default '
+                    'since 0.4.0. Please remove these keys from state_dict. If '
+                    'the running stats are actually needed, instead set '
+                    'track_running_stats=True in {klass} to enable them. See '
+                    'the documentation of {klass} for details.'
+                    .format(names=" and ".join('"{}"'.format(k) for k in running_stats_keys),
+                            klass=self.__class__.__name__))
+                for key in running_stats_keys:
+                    state_dict.pop(key)
+
+        super(_InstanceNormNVFuser, self)._load_from_state_dict(
+            state_dict, prefix, local_metadata, strict,
+            missing_keys, unexpected_keys, error_msgs)
+
+    def forward(self, input: Tensor) -> Tensor:
+        assert input.is_cuda, "NVFuser InstanceNorm is CUDA only"
+        self._check_input_dim(input)
+        if self.running_mean is not None:
+            out = InstanceNormNVFuserFunction.apply(
+                    input, self.weight if self.weight is not None else self.dummy,
+                    self.bias if self.bias is not None else self.dummy, self.running_mean, self.running_var,
+                    self.training or not self.track_running_stats, self.momentum, self.eps)
+        else:
+            out = InstanceNormNVFuserFunction.apply(
+                    input, self.weight if self.weight is not None else self.dummy,
+                    self.bias if self.bias is not None else self.dummy, self.dummy, self.dummy,
+                    self.training or not self.track_running_stats, self.momentum, self.eps)
+        return out
+
+class InstanceNorm3dNVFuser(_InstanceNormNVFuser):
+    def _check_input_dim(self, input):
+        if input.dim() != 5:
+            raise ValueError('expected 5D input (got {}D input)'
+                             .format(input.dim()))
+

csrc/instance_norm_nvfuser.cpp

@@ -0,0 +1,35 @@
+#include <iostream>
+#include <vector>
+
+#include <torch/extension.h>
+
+std::vector<at::Tensor> instance_norm_nvfuser_forward(
+  at::Tensor input,
+  at::Tensor weight,
+  at::Tensor bias,
+  at::Tensor run_mean,
+  at::Tensor run_var,
+  const bool use_input_stats,
+  const float momentum,
+  const float eps,
+  const bool channels_last = false
+  );
+
+std::vector<at::Tensor> instance_norm_nvfuser_backward(
+  at::Tensor input,
+  at::Tensor grad_output,
+  at::Tensor weight,
+  at::Tensor running_mean,
+  at::Tensor running_var,
+  at::Tensor save_mean,
+  at::Tensor save_invstd,
+  const bool use_input_stats,
+  const float eps,
+  // const std::vector<bool>& output_mask,
+  bool channels_last = false
+  );
+
+PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
+  m.def("forward", &instance_norm_nvfuser_forward, "instance_norm forward (CUDA)");
+  m.def("backward", &instance_norm_nvfuser_backward, "instance_norm backward (CUDA)");
+}