Add more helper methods in 'DeviceElementwise'

include/ck/tensor_operation/gpu/device/device_elementwise.hpp

@@ -222,14 +222,9 @@ struct DeviceElementwise
         }
     };
 
-    bool IsSupportedArgument(const BaseArgument* p_arg) override
+    static bool IsSupportedArgument(const Argument& arg)
     {
-        const Argument* pArg = dynamic_cast<const Argument*>(p_arg);
-
-        if(pArg == nullptr)
-            return false;
-
-        if(pArg->lengths_.back() % MPerThread != 0)
+        if(arg.lengths_.back() % MPerThread != 0)
             return false;
 
         auto IsScalarPerVectorValid = [&](const std::array<index_t, NumDim>& lengths,
@@ -247,19 +242,34 @@ struct DeviceElementwise
         bool valid = true;
         static_for<0, NumInput, 1>{}([&](auto I) {
             if(!IsScalarPerVectorValid(
-                   pArg->lengths_, pArg->inStridesArray_[I.value], InScalarPerVectorSeq::At(I)))
+                   arg.lengths_, arg.inStridesArray_[I.value], InScalarPerVectorSeq::At(I)))
                 valid = false;
         });
 
         static_for<0, NumOutput, 1>{}([&](auto I) {
             if(!IsScalarPerVectorValid(
-                   pArg->lengths_, pArg->outStridesArray_[I.value], OutScalarPerVectorSeq::At(I)))
+                   arg.lengths_, arg.outStridesArray_[I.value], OutScalarPerVectorSeq::At(I)))
                 valid = false;
         });
 
         return valid;
     };
 
+    bool IsSupportedArgument(const BaseArgument* p_arg) override
+    {
+        return IsSupportedArgument(*dynamic_cast<const Argument*>(p_arg));
+    }
+
+    static auto MakeArgument(const std::array<index_t, NumDim> lengths,
+                 const std::array<std::array<index_t, NumDim>, NumInput> inStridesArray,
+                 const std::array<std::array<index_t, NumDim>, NumOutput> outStridesArray,
+                 const std::array<const void*, NumInput> in_dev_buffers,
+                 const std::array<void*, NumOutput> out_dev_buffers,
+                 ElementwiseOperation elementwise_op)
+    {
+       return Argument{lengths, inStridesArray, outStridesArray, in_dev_buffers, out_dev_buffers, elementwise_op};
+    }
+
     std::unique_ptr<BaseArgument>
     MakeArgumentPointer(const std::array<index_t, NumDim> lengths,
                         const std::array<std::array<index_t, NumDim>, NumInput> inStridesArray,