Initial

src/include/migraphx/op/topk.hpp

@@ -42,6 +42,7 @@ struct topk
     int64_t k        = 1;
     int64_t axis     = 0;
     bool largest     = true;
+    bool use_dynamic = false;
 
     template <class Self, class F>
     static auto reflect(Self& self, F f)
@@ -60,15 +61,40 @@ struct topk
 
     shape normalize_compute_shape(std::vector<shape> inputs) const
     {
+        if(use_dynamic)
+        {
+            // input tensor and k value
+            check_shapes{inputs, *this, true}.has(2);
+            auto type = inputs.at(0).type();
+            std::vector<shape::dynamic_dimension> dyn_dims;
+            if(inputs.at(0).dynamic())
+            {
+                dyn_dims = inputs.at(0).dyn_dims();
+            }
+            else
+            {
+                auto dyn_shape = fixed_to_dynamic(inputs.at(0));
+                dyn_dims       = dyn_shape.dyn_dims();
+            }
+            shape s_val{type, dyn_dims};
+            shape s_ind{shape::int64_type, dyn_dims};
+            return {{s_val, s_ind}};
+        }
+        else
+        {
+            return fixed_compute_shape(inputs, this->k);
+        }
+    }
+
+    shape fixed_compute_shape(std::vector<shape> inputs, int64_t in_k) const
+    {
+        // TODO: is standard layout needed here? No, it should not be needed.
         check_shapes{inputs, *this}.has(1).standard();
         auto lens  = inputs.at(0).lens();
         auto type  = inputs.at(0).type();
-
-        lens[axis] = k;
-
+        lens[axis] = in_k;
         shape s_val{type, lens};
         shape s_ind{shape::int64_type, lens};
-
         return {{s_val, s_ind}};
     }
 
@@ -109,7 +135,10 @@ struct topk
 
     argument compute(const shape& output_shape, std::vector<argument> args) const
     {
-        auto vec_ss = output_shape.sub_shapes();
+        auto vec_ss =
+            use_dynamic ? fixed_compute_shape({args.front().get_shape()}, args.at(1).at<int64_t>())
+                              .sub_shapes()
+                        : output_shape.sub_shapes();
         argument res_val{vec_ss.front()};
         argument res_ind{vec_ss.back()};
         auto in_s      = args.front().get_shape();

src/include/migraphx/shape.hpp

@@ -332,6 +332,11 @@ struct shape
 void migraphx_to_value(value& v, const shape& s);
 void migraphx_from_value(const value& v, shape& s);
 
+/*!
+ * Make a dynamic shape from a fixed shape.
+ */
+shape fixed_to_dynamic(const shape& s);
+
 } // namespace MIGRAPHX_INLINE_NS
 } // namespace migraphx
 

src/shape.cpp

@@ -577,5 +577,15 @@ void migraphx_from_value(const value& v, shape& s)
     }
 }
 
+shape fixed_to_dynamic(const shape& s)
+{
+    auto fixed_lens = s.lens();
+    std::vector<shape::dynamic_dimension> dyn_dims;
+    std::transform(fixed_lens.cbegin(), fixed_lens.cend(), dyn_dims.begin(), [](auto l) {
+        return shape::dynamic_dimension{l, l, 0};
+    });
+    return {s.type(), dyn_dims};
+}
+
 } // namespace MIGRAPHX_INLINE_NS
 } // namespace migraphx