Add broadcast div, the final step of softmax

example/19_gemm_softmax/gemm_softmax_xdl_fp16.cpp

@@ -155,9 +155,21 @@ struct Sub_Exp
     }
 };
 
-using DeviceElementwiseInstance = ck::tensor_operation::device::
+struct Div
+{
+    __host__ __device__ constexpr void
+    operator()(CDataType& dst, const CDataType& src1, const CDataType& src2) const
+    {
+        dst = src1 / src2;
+    }
+};
+
+using DeviceElementwiseSubExpInstance = ck::tensor_operation::device::
     DeviceElementwise_2D<CDataType, CDataType, CDataType, Sub_Exp, 16, 16, 8, 8, 1, 1, 1, 1, 1>;
 
+using DeviceElementwiseDivInstance = ck::tensor_operation::device::
+    DeviceElementwise_2D<CDataType, CDataType, CDataType, Div, 16, 16, 8, 8, 1, 1, 1, 1, 1>;
+
 using ReferenceGemmInstance = ck::tensor_operation::host::
     ReferenceGemm<ADataType, BDataType, CDataType, PassThrough, PassThrough, PassThrough>;
 
@@ -230,6 +242,7 @@ int main(int argc, char* argv[])
     Tensor<CDataType> exp_m_n(f_host_tensor_descriptor(M, N, StrideC, CLayout{}));
     Tensor<CDataType> exp_n_sum(std::vector<std::size_t>({static_cast<std::size_t>(N)}),
                                 std::vector<std::size_t>({1}));
+    Tensor<CDataType> softmax_m_n(f_host_tensor_descriptor(M, N, StrideC, CLayout{}));
 
     const auto c_m_n_shape     = ck::to_int_vector(c_m_n.mDesc.GetLengths());
     const auto c_m_n_stride    = ck::to_int_vector(c_m_n.mDesc.GetStrides());
@@ -244,6 +257,7 @@ int main(int argc, char* argv[])
     std::cout << "c_n_max: " << c_n_max.mDesc << std::endl;
     std::cout << "exp_m_n: " << exp_m_n.mDesc << std::endl;
     std::cout << "exp_n_sum: " << exp_n_sum.mDesc << std::endl;
+    std::cout << "softmax_m_n: " << softmax_m_n.mDesc << std::endl;
 
     switch(init_method)
     {
@@ -264,6 +278,7 @@ int main(int argc, char* argv[])
     DeviceMem indices_device_buf(0);
     DeviceMem exp_m_n_device_buf(sizeof(CDataType) * exp_m_n.mDesc.GetElementSpace());
     DeviceMem exp_n_sum_device_buf(sizeof(CDataType) * exp_n_sum.mDesc.GetElementSpace());
+    DeviceMem softmax_m_n_device_buf(sizeof(CDataType) * softmax_m_n.mDesc.GetElementSpace());
 
     a_m_k_device_buf.ToDevice(a_m_k.mData.data());
     b_k_n_device_buf.ToDevice(b_k_n.mData.data());
@@ -324,7 +339,7 @@ int main(int argc, char* argv[])
     reduce_max_invoker_ptr->Run(reduce_max_argument_ptr.get(), nrepeat);
 
     // do broadcast sub and exp
-    auto broadcastSubExp = DeviceElementwiseInstance{};
+    auto broadcastSubExp = DeviceElementwiseSubExpInstance{};
     auto broadcastSubExp_argument_ptr =
         broadcastSubExp.MakeArgumentPointer(c_m_n_device_buf.GetDeviceBuffer(),
                                             c_n_max_device_buf.GetDeviceBuffer(),
@@ -373,7 +388,27 @@ int main(int argc, char* argv[])
     auto reduce_sum_invoker_ptr = reduce_sum.MakeInvokerPointer();
     reduce_sum_invoker_ptr->Run(reduce_sum_argument_ptr.get(), nrepeat);
 
-    // TODO - Need BroadcastDiv
+    // do broadcast div
+    auto broadcastDiv = DeviceElementwiseDivInstance{};
+    auto broadcastDiv_argument_ptr =
+        broadcastDiv.MakeArgumentPointer(exp_m_n_device_buf.GetDeviceBuffer(),
+                                         exp_n_sum_device_buf.GetDeviceBuffer(),
+                                         softmax_m_n_device_buf.GetDeviceBuffer(),
+                                         {M, N},
+                                         {StrideC, 1},
+                                         {0, 1},
+                                         {StrideC, 1},
+                                         Div{});
+
+    if(!broadcastDiv.IsSupportedArgument(broadcastDiv_argument_ptr.get()))
+    {
+        throw std::runtime_error("The runtime parameters seems not supported by the "
+                                 "DeviceElementwise_2D instance, exiting!");
+    };
+
+    auto broadcastDiv_invoker_ptr = broadcastDiv.MakeInvokerPointer();
+    broadcastDiv_invoker_ptr->Run(broadcastDiv_argument_ptr.get(), nrepeat);
+
     // TODO = do_verification
     (void)do_verification;
     return 0;