- concat empty scalar fix

- couple of tests for empty scalar concat

Signed-off-by: raver119 <raver119@gmail.com>

libnd4j/include/ops/declarable/generic/transforms/concat.cpp

@@ -124,7 +124,9 @@ DECLARE_SHAPE_FN(concat) {
     for(int i = 0; i < block.width(); ++i) {
 
         if(inputShape->at(i)[0] == 0) {
-            // FIXME, use this instead: block.dataType()
+            if (shape::isEmpty(inputShape->at(i)))
+                arrShapes.push_back(ConstantShapeHelper::getInstance()->vectorShapeInfo(0, INPUT_VARIABLE(0)->dataType()));
+            else
                 arrShapes.push_back(ConstantShapeHelper::getInstance()->vectorShapeInfo(1, INPUT_VARIABLE(0)->dataType()));
         }
         else{
@@ -165,7 +167,9 @@ DECLARE_SHAPE_FN(concat) {
     }
 
     for(int i = 1; i < numOfArrs; ++i)
+        if (!shape::isEmpty(arrShapes[i])) {
             outShapeInfo[axis + 1] += arrShapes[i][axis + 1];
+        }
 
     ShapeUtils::updateStridesAndType(outShapeInfo, arrShapes[0], shape::order(arrShapes[0]));
 

libnd4j/tests_cpu/layers_tests/EmptyTests.cpp

@@ -107,6 +107,46 @@ TEST_F(EmptyTests, Test_Concat_2) {
     delete result;
 }
 
+TEST_F(EmptyTests, Test_Concat_3) {
+    auto empty = NDArrayFactory::empty<float>(); //NDArrayFactory::empty_<float>();
+    auto scalar1 =  NDArrayFactory::create<float>(1.0f);
+    auto scalar2  = NDArrayFactory::create<float>(2.0f);
+    auto exp = NDArrayFactory::create<float>('c', {2}, {1.f, 2.f});
+
+    ASSERT_TRUE(empty.isEmpty());
+
+    nd4j::ops::concat op;
+    auto result = op.execute({&empty, &scalar1, &scalar2}, {}, {0});
+    ASSERT_EQ(Status::OK(), result->status());
+
+    auto z = result->at(0);
+
+    z->printIndexedBuffer("z");
+    ASSERT_EQ(exp, *z);
+
+    delete result;
+}
+
+TEST_F(EmptyTests, Test_Concat_4) {
+    auto empty = NDArrayFactory::empty<float>(); //NDArrayFactory::empty_<float>();
+    auto scalar1 =  NDArrayFactory::create<float>(1.0f);
+    auto scalar2  = NDArrayFactory::create<float>(2.0f);
+    auto exp = NDArrayFactory::create<float>('c', {2}, {1.f, 2.f});
+
+    ASSERT_TRUE(empty.isEmpty());
+
+    nd4j::ops::concat op;
+    auto result = op.execute({&scalar1, &empty, &scalar2}, {}, {0});
+    ASSERT_EQ(Status::OK(), result->status());
+
+    auto z = result->at(0);
+
+    z->printIndexedBuffer("z");
+    ASSERT_EQ(exp, *z);
+
+    delete result;
+}
+
 TEST_F(EmptyTests, Test_Reshape_1) {
     auto vector = NDArrayFactory::create<float>('c', {1}, {119.0f});
     auto exp = NDArrayFactory::create<float>(119.f);