Merge pull request #157 from ROCmSoftwarePlatform/onnx-multi-out

Add support for multiple outputs in onnx parser

src/onnx/onnx.cpp

@@ -24,7 +24,8 @@ struct onnx_parser
 {
     using attribute_map = std::unordered_map<std::string, onnx::AttributeProto>;
     using node_map      = std::unordered_map<std::string, onnx::NodeProto>;
-    using op_func = std::function<instruction_ref(attribute_map, std::vector<instruction_ref>)>;
+    using op_func =
+        std::function<std::vector<instruction_ref>(attribute_map, std::vector<instruction_ref>)>;
     node_map nodes;
     std::unordered_map<std::string, instruction_ref> instructions;
     program prog    = program();
@@ -88,6 +89,15 @@ struct onnx_parser
 
     template <class F>
     void add_op(std::string name, F f)
+    {
+        ops.emplace(name, [=](auto&&... xs) {
+            return std::vector<instruction_ref>{f(std::forward<decltype(xs)>(xs)...)};
+        });
+    }
+
+    // Multi output op
+    template <class F>
+    void add_multi_op(std::string name, F f)
     {
         ops.emplace(name, f);
     }
@@ -95,7 +105,7 @@ struct onnx_parser
     template <class F>
     void add_mem_op(std::string name, F f)
     {
-        ops.emplace(name, [=](auto&&... xs) {
+        add_op(name, [=](auto&&... xs) {
             return std::mem_fn(f)(*this, name, std::forward<decltype(xs)>(xs)...);
         });
     }
@@ -103,7 +113,7 @@ struct onnx_parser
     template <class T>
     void add_binary_op(std::string name, T x)
     {
-        ops.emplace(name, [this, x](attribute_map attributes, std::vector<instruction_ref> args) {
+        add_op(name, [this, x](attribute_map attributes, std::vector<instruction_ref> args) {
             if(args.size() != 2)
                 MIGRAPHX_THROW("binary operators should have 2 operands");
             if(contains(attributes, "broadcast") and contains(attributes, "axis"))
@@ -172,7 +182,7 @@ struct onnx_parser
     template <class T>
     void add_generic_op(std::string name, T x)
     {
-        ops.emplace(name, [this, x](attribute_map, std::vector<instruction_ref> args) {
+        add_op(name, [this, x](attribute_map, std::vector<instruction_ref> args) {
             return prog.add_instruction(x, args);
         });
     }
@@ -180,7 +190,7 @@ struct onnx_parser
     template <class T>
     void add_variadic_op(std::string name, T x)
     {
-        ops.emplace(name, [this, x](attribute_map, std::vector<instruction_ref> args) {
+        add_op(name, [this, x](attribute_map, std::vector<instruction_ref> args) {
             return std::accumulate(std::next(args.begin()),
                                    args.end(),
                                    args.front(),
@@ -643,7 +653,7 @@ struct onnx_parser
         }
         else
         {
-            throw std::runtime_error("Failed reading");
+            MIGRAPHX_THROW("Failed reading onnx file.");
         }
     }
 
@@ -673,7 +683,7 @@ struct onnx_parser
         }
         for(auto&& p : nodes)
         {
-            this->parse_node(get_name(p.second));
+            this->parse_node(p.first);
         }
     }
 
@@ -689,23 +699,37 @@ struct onnx_parser
             {
                 if(nodes.count(input) > 0)
                 {
-                    auto&& iname = get_name(nodes.at(input));
-                    assert(name != iname);
-                    this->parse_node(iname);
-                    args.push_back(instructions.at(iname));
+                    assert(name != input);
+                    this->parse_node(input);
+                    args.push_back(instructions.at(input));
                 }
                 else
                 {
                     args.push_back(instructions.at(input));
                 }
             }
+            std::vector<instruction_ref> result;
             if(ops.count(node.op_type()) == 0)
             {
-                instructions[name] = prog.add_instruction(unknown{node.op_type()}, args);
+                result.push_back(prog.add_instruction(unknown{node.op_type()}, args));
             }
             else
             {
-                instructions[name] = ops[node.op_type()](get_attributes(node), args);
+                result = ops[node.op_type()](get_attributes(node), args);
+            }
+            // Even no output nodes produce output in migraphx
+            if(node.output().empty() and result.size() == 1)
+            {
+                instructions[name] = result.front();
+            }
+            else
+            {
+                assert(node.output().size() >= result.size());
+                std::transform(result.begin(),
+                               result.end(),
+                               node.output().begin(),
+                               std::inserter(instructions, instructions.end()),
+                               [](auto&& x, auto&& y) { return std::make_pair(y, x); });
             }
         }
     }
@@ -720,25 +744,24 @@ struct onnx_parser
         return result;
     }
 
-    static std::string get_name(const onnx::NodeProto& node)
-    {
-        if(node.name().empty())
-        {
-            std::string generated = "migraphx_unnamed_node";
-            return std::accumulate(node.output().begin(),
-                                   node.output().end(),
-                                   generated,
-                                   [](auto x, auto y) { return x + "_" + y; });
-        }
-        return node.name();
-    }
-
     static node_map get_nodes(const onnx::GraphProto& graph)
     {
         std::unordered_map<std::string, onnx::NodeProto> result;
+        std::size_t n = 0;
         for(auto&& node : graph.node())
         {
-            result[get_name(node)] = node;
+            if(node.output().empty())
+            {
+                if(node.name().empty())
+                {
+                    result["migraphx_unamed_node_" + std::to_string(n)] = node;
+                    n++;
+                }
+                else
+                {
+                    result[node.name()] = node;
+                }
+            }
             for(auto&& output : node.output())
             {
                 result[output] = node;