Add more validation

src/include/migraph/instruction.hpp

@@ -62,16 +62,26 @@ struct instruction
         return std::addressof(i) == std::addressof(*ref);
     }
 
-    bool valid() const
+    bool valid(instruction_ref start) const
     {
-        return std::all_of(output.begin(),
+        std::vector<shape> shapes(arguments.size());
+        std::transform(arguments.begin(), arguments.end(), shapes.begin(), [](instruction_ref ins) { return ins->result; });
+        shape computed;
+        try
+        {
+            computed = op.compute_shape(shapes);
+        } 
+        catch(migraph::exception&) { return false; }
+        return result == computed &&
+        std::all_of(output.begin(),
                            output.end(),
                            [&](instruction_ref i) {
                                return std::find(i->arguments.begin(), i->arguments.end(), *this) !=
                                       i->arguments.end();
                            }) &&
                std::all_of(arguments.begin(), arguments.end(), [&](instruction_ref i) {
-                   return std::find(i->output.begin(), i->output.end(), *this) != i->output.end();
+                   auto self = std::find(i->output.begin(), i->output.end(), *this);
+                   return self != i->output.end() && std::distance(start, i) < std::distance(start, *self);
                });
     }
 

src/program.cpp

@@ -129,7 +129,7 @@ instruction_ref program::validate() const
 {
     return std::find_if(impl->instructions.begin(),
                         impl->instructions.end(),
-                        [](const instruction& i) { return i.valid(); });
+                        [&](const instruction& i) { return i.valid(impl->instructions.begin()); });
 }
 
 void program::compile(const target& t)