Upload apex-master/csrc/megatron/scaled_upper_triang_masked_softmax_cuda.cu with huggingface_hub

apex-master/csrc/megatron/scaled_upper_triang_masked_softmax_cuda.cu

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+/* coding=utf-8
+ * Copyright (c) 2021, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ATen/ATen.h>
+#include <cuda.h>
+#include <cuda_runtime.h>
+#include <cuda_fp16.h>
+#include <cuda_profiler_api.h>
+#include <ATen/cuda/CUDAContext.h>
+#include <torch/extension.h>
+#include "scaled_upper_triang_masked_softmax.h"
+#include "type_shim.h"
+
+namespace multihead_attn {
+namespace fused_softmax {
+namespace scaled_upper_triang_masked_softmax {
+
+torch::Tensor fwd_cuda(
+    torch::Tensor const& input, 
+    float scale_factor)
+{
+  // input is a 3d tensor with dimensions [attn_batches, seq_len, seq_len]
+  const int attn_batches = input.size(0);
+  const int seq_len = input.size(1);
+  TORCH_INTERNAL_ASSERT(seq_len <= 16384);
+
+  // Output 
+  auto act_options = input.options().requires_grad(false);
+  torch::Tensor softmax_results = 
+      torch::empty({attn_batches, seq_len, seq_len}, act_options);
+
+  // Softmax Intermediate Result Ptr
+  void* input_ptr = static_cast<void*>(input.data_ptr());
+  void* softmax_results_ptr = static_cast<void*>(softmax_results.data_ptr());
+
+  DISPATCH_HALF_AND_BFLOAT(
+      input.scalar_type(),
+      "dispatch_scaled_upper_triang_masked_softmax_forward",
+      dispatch_scaled_upper_triang_masked_softmax_forward<scalar_t, scalar_t, float>(
+	  reinterpret_cast<scalar_t*>(softmax_results_ptr),
+	  reinterpret_cast<const scalar_t*>(input_ptr),
+	  scale_factor,
+	  seq_len,
+	  seq_len,
+	  attn_batches);
+      );
+  return softmax_results;
+}
+				      
+
+torch::Tensor bwd_cuda(
+    torch::Tensor const& output_grads_, 
+    torch::Tensor const& softmax_results_, 
+    float scale_factor)  {
+	
+  auto output_grads = output_grads_.contiguous();
+  auto softmax_results = softmax_results_.contiguous();
+
+  //output grads is a 3d tensor with dimensions [attn_batches, seq_len, seq_len]
+  const int attn_batches = output_grads.size(0);
+  const int seq_len = output_grads.size(1);
+  TORCH_INTERNAL_ASSERT(output_grads.size(1) == output_grads.size(2));
+
+  void* output_grads_ptr = static_cast<void*>(output_grads.data_ptr());
+
+  //Softmax Grad
+  DISPATCH_HALF_AND_BFLOAT(
+      output_grads_.scalar_type(),
+      "dispatch_scaled_upper_triang_masked_softmax_backward",
+      dispatch_scaled_upper_triang_masked_softmax_backward<scalar_t, scalar_t, float>(
+          reinterpret_cast<scalar_t*>(output_grads_ptr), 
+	  reinterpret_cast<scalar_t*>(output_grads_ptr), 
+	  reinterpret_cast<scalar_t const*>(softmax_results.data_ptr()),
+	  scale_factor,
+	  seq_len,
+	  seq_len,
+	  attn_batches);
+      );
+  
+  //backward pass is completely in-place
+  return output_grads;
+}
+}
+}
+}