Rewrite add splits

src/simplify_algebra.cpp

@@ -773,6 +773,37 @@ struct find_split_concat
     }
 };
 
+struct find_add_split
+{
+    auto matcher() const
+    {
+        auto add = [](auto... ms) {
+            return match::name("add")(match::either_arg(0, 1)(ms...));
+        };
+        auto slice = match::name("slice").bind("slice");
+        auto constant = match::is_constant().bind("a");
+        auto any = match::any().bind("x");
+        auto slice_a_x = add(slice, add(constant, any));
+        auto a_slice_x = add(constant, add(slice, any));
+        return match::any_of(
+                slice_a_x,
+                a_slice_x
+            );
+    }
+
+    void apply(module& m, const match::matcher_result& r) const
+    {
+        auto ins = r.result;
+        auto slice = r.instructions["slice"];
+        auto a = r.instructions["a"];
+        auto x = r.instructions["x"];
+
+        auto slice_add = m.insert_instruction(ins, migraphx::make_op("add"), slice, a);
+        m.replace_instruction(ins, migraphx::make_op("add"), slice_add, x);
+
+    }
+};
+
 bool axis_equal(const std::vector<std::size_t>& x,
                 const std::vector<std::size_t>& y,
                 std::size_t axis)
@@ -1235,6 +1266,7 @@ void simplify_algebra::apply(module& m) const
                             find_div_const{},
                             find_sub_const{},
                             find_rsqrt{},
+                            find_add_split{},
                             find_concat_op{},
                             find_split_concat{},
                             find_splits{},