text: #include <torch/extension.h>
  
  // CUDA forward declaration
  void fused_adam_cuda(at::Tensor & p, at::Tensor & p_copy, at::Tensor & m, at::Tensor & v, at::Tensor & g, float lr, float beta1, float beta2, float eps, float grad_scale, int step, int mode);
  
  #define CHECK_CUDA(x) AT_ASSERTM(x.type().is_cuda(), #x " must be a CUDA tensor")
  #define CHECK_CONTIGUOUS(x) AT_ASSERTM(x.is_contiguous(), #x " must be contiguous")
  #define CHECK_INPUT(x) CHECK_CUDA(x); CHECK_CONTIGUOUS(x)
  
  // C++ interface
  void adam(at::Tensor & p, at::Tensor & p_copy, at::Tensor & m, at::Tensor & v, at::Tensor & g, float lr, float beta1, float beta2, float eps, float grad_scale, int step, int mode) {
          CHECK_INPUT(p)
          if (p_copy.numel() > 0) CHECK_INPUT(p_copy);
          CHECK_INPUT(m);
          CHECK_INPUT(v);
          CHECK_INPUT(g);
          int64_t num_elem = p.numel();
          AT_ASSERTM(m.numel() == num_elem, "number of elements in m and p tensors should be equal");
          AT_ASSERTM(v.numel() == num_elem, "number of elements in v and p tensors should be equal");
          AT_ASSERTM(g.numel() == num_elem, "number of elements in g and p tensors should be equal");
          AT_ASSERTM(p_copy.numel() == num_elem || p_copy.numel() == 0, "number of elements in p_copy and p tensors should be equal, or p_copy should be empty");
  
          fused_adam_cuda(p, p_copy, m, v, g, lr, beta1, beta2, eps, grad_scale, step, mode);
  }
  
  PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
          m.def("adam", &adam, "Adam optimized CUDA implementation.");
  }
  