add contraction_bilinear

example/26_contraction/CMakeLists.txt

 add_example_executable(example_contraction_bilinear_xdl_fp32 contraction_bilinear_xdl_fp32.cpp)
 add_example_executable(example_contraction_scale_xdl_fp32 contraction_scale_xdl_fp32.cpp)
+
+add_example_executable(example_contraction_bilinear_xdl_fp64 contraction_bilinear_xdl_fp64.cpp)

include/ck/tensor_operation/gpu/element/binary_element_wise_operation.hpp

@@ -118,6 +118,13 @@ struct Bilinear
     template <typename Y, typename X0, typename X1>
     __host__ __device__ constexpr void operator()(Y&, const X0&, const X1&) const;
 
+    template <>
+    __host__ __device__ constexpr void
+    operator()<double, double, double>(double& y, const double& x0, const double& x1) const
+    {
+        y = alpha_ * x0 + beta_ * x1;
+    };
+
     template <>
     __host__ __device__ constexpr void
     operator()<float, float, float>(float& y, const float& x0, const float& x1) const