Merge pull request #221 from NervanaSystems/aprocter/autodiff_nested_adds

Fix bug with multiple updates to adjoint map

src/ngraph/autodiff/adjoints.cpp

@@ -160,6 +160,6 @@ void autodiff::Adjoints::add_delta(const std::shared_ptr<Node>& x,
     }
     else
     {
-        m_adjoint_map.insert({x.get(), std::make_shared<op::Add>(adjoint_it->second, delta)});
+        adjoint_it->second = std::make_shared<op::Add>(adjoint_it->second, delta);
     }
 }

test/CMakeLists.txt

@@ -22,6 +22,7 @@ include_directories(
     )
 
 set (SRC
+    autodiff.cpp
     build_graph.cpp
     eigen.cpp
     execute.cpp
@@ -36,7 +37,6 @@ set (SRC
     topological_sort.cpp
     type_prop.cpp
     util/all_close.cpp
-    util/autodiff.cpp
     util/test_tools.cpp
     util.cpp
     uuid.cpp

test/util/autodiff.cpp → test/autodiff.cpp

@@ -19,12 +19,12 @@
 
 #include "gtest/gtest.h"
 
-#include "all_close.hpp"
 #include "ngraph/autodiff/backprop_derivative.hpp"
 #include "ngraph/autodiff/backprop_function.hpp"
 #include "ngraph/autodiff/numeric_derivative.hpp"
 #include "ngraph/ngraph.hpp"
-#include "random.hpp"
+#include "util/all_close.hpp"
+#include "util/random.hpp"
 
 using namespace std;
 using namespace ngraph;
@@ -65,6 +65,26 @@ TEST(backwards, add)
         manager, backend, make_graph, {x0, x1}, .01f, .01f));
 }
 
+TEST(backwards, add_nested)
+{
+    auto manager = runtime::Manager::get("NGVM");
+    auto backend = manager->allocate_backend();
+
+    test::Uniform<element::Float32> rng(-1.0f, 1.0f);
+    auto shape = Shape{2, 3};
+    auto x0 = rng.initialize(backend->make_parameterized_tensor_view<element::Float32>(shape));
+    auto x1 = rng.initialize(backend->make_parameterized_tensor_view<element::Float32>(shape));
+
+    auto make_graph = [shape]() {
+        auto X0 = make_shared<op::Parameter>(element::Float32::element_type(), shape);
+        auto X1 = make_shared<op::Parameter>(element::Float32::element_type(), shape);
+        return make_shared<Function>(
+            (X0 + X1) + (X1 + X0), nullptr, std::vector<std::shared_ptr<op::Parameter>>{X0, X1});
+    };
+    EXPECT_TRUE(autodiff_numeric_compare<element::Float32>(
+        manager, backend, make_graph, {x0, x1}, .01f, .01f));
+}
+
 TEST(backwards, broadcast0)
 {
     auto manager = runtime::Manager::get("NGVM");