Interpolate tuning param

src/targets/gpu/jit/ck_gemm.cpp

@@ -137,6 +137,8 @@ struct instance
     std::string str() const { return join_strings(params, ","); }
 };
 
+static bool transposed_matrix(const shape& s) { return s.strides().back() != 1; }
+
 template <class F, class Action>
 auto action_decorate(F f, Action action)
 {
@@ -154,6 +156,18 @@ static std::vector<tuning_entry> read_tuning(const std::string& s)
     return from_value<std::vector<tuning_entry>>(from_json_string(read_string(s)));
 }
 
+static float matrix_distance(const shape& x, const shape& y)
+{
+    if (x.type() != y.type())
+        return std::numeric_limits<float>::max();
+    if (transposed_matrix(x) != transposed_matrix(y))
+        return std::numeric_limits<float>::max();
+    auto sum_squared = std::inner_product(x.lens().rbegin(), x.lens().rbegin()+2, y.lens().rbegin(), 0, std::plus<>{}, [](auto a, auto b) {
+        return (a - b) * (a - b);
+    });
+    return std::sqrt(sum_squared);
+}
+
 static std::size_t get_tuning_for(const std::vector<shape>& inputs)
 {
     static auto tuning = read_tuning(string_value_of(MIGRAPHX_CK_TUNING{}, ""));
@@ -164,14 +178,26 @@ static std::size_t get_tuning_for(const std::vector<shape>& inputs)
     if(it == tuning.end())
     {
         std::cout << "*********** Warning: CK tuning missing for config!" << std::endl;
-        return value_of(MIGRAPHX_CK_TUNING_VALUE{}, 4);
+        std::vector<std::pair<float, std::size_t>> w;
+        std::transform(tuning.begin(), tuning.end(), std::back_inserter(w), [&](const auto& p) {
+            if (inputs.size() < 3 or p.first.size() < 3)
+                MIGRAPHX_THROW("Invalid CK config");
+            auto avg_distance = std::inner_product(p.first.begin(), p.first.begin()+3, inputs.begin(), 0.0f, std::plus<>{}, [](const auto& x, const auto& y) {
+                return matrix_distance(x, y) / 3.0f;
+            });
+            return std::make_pair(avg_distance, p.second);
+        });
+        std::sort(w.begin(), w.end());
+        std::size_t default_value = 4;
+        if (not w.empty())
+            default_value = w.front().second;
+        return value_of(MIGRAPHX_CK_TUNING_VALUE{}, default_value);
     }
     return it->second;
 }
 
 struct ck_gemm_compiler : compiler<ck_gemm_compiler>
 {
-    static bool transposed_matrix(const shape& s) { return s.strides().back() != 1; }
     static std::string get_layout(const shape& s)
     {
         return transposed_matrix(s) ? "ck::tensor_layout::gemm::ColumnMajor"