From 679e42199ae30f06561fa682946e8a3e254e22c1 Mon Sep 17 00:00:00 2001
From: shugeo <sgazeos@gmail.com>
Date: Thu, 7 Nov 2019 12:44:02 +0200
Subject: [PATCH] Shugeo strided slice bp fix2 (#33)

* Fixed crash and restored brocken functionality for strided slice.

* Added comments for strided_slice_bp main step.
---
 .../generic/parity_ops/strided_slice.cpp      | 13 +++++----
 .../layers_tests/DeclarableOpsTests6.cpp      | 28 ++++++++++++++++++-
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/libnd4j/include/ops/declarable/generic/parity_ops/strided_slice.cpp b/libnd4j/include/ops/declarable/generic/parity_ops/strided_slice.cpp
index e0bc57923..4b622e821 100644
--- a/libnd4j/include/ops/declarable/generic/parity_ops/strided_slice.cpp
+++ b/libnd4j/include/ops/declarable/generic/parity_ops/strided_slice.cpp
@@ -620,14 +620,15 @@ namespace nd4j {
             // FIXME: remove this method once we get 1D vectors supported
             vectorize(input_shape);
             REQUIRE_TRUE(_preprocess_strided_slice(&indices, &final_shape, input_shape, begin, end, strides, begin_mask, ellipsis_mask, end_mask, new_axis_mask, shrink_axis_mask, &is_identity, &is_simple_slice, &is_dim0), 0, "StridedSliceBP: shape calculation failed");
-
-			//Zero output array, so unused elements have 0 gradient
-			output->nullify();
-            std::sort(indices.begin(), indices.end());
-            if(indices.size() == 3 && (indices[1] - indices[0]) == 1) {
+            //REQUIRE_TRUE(epsNext->isSameShape(final_shape), 0, "StridedSlice_bp: gradOut shape should be equals to output from strided_slice op.");
+            //Zero output array, so unused elements have 0 gradient
+            output->nullify();
+            //
+            // the first case: only for scalar gradient step
+            if(epsNext->lengthOf() == 1 && (indices.size() == 3 && (indices[1] - indices[0]) == 1 || (indices[2] - indices[0] == 1))) {
                 output->p(indices[0], *epsNext);
             }
-            else {
+            else { // else for other cases
                 auto sub = (*output)(indices, true, true);
                 sub.assign(epsNext);
             }           
diff --git a/libnd4j/tests_cpu/layers_tests/DeclarableOpsTests6.cpp b/libnd4j/tests_cpu/layers_tests/DeclarableOpsTests6.cpp
index b1d080b20..34b66c61a 100644
--- a/libnd4j/tests_cpu/layers_tests/DeclarableOpsTests6.cpp
+++ b/libnd4j/tests_cpu/layers_tests/DeclarableOpsTests6.cpp
@@ -248,7 +248,7 @@ TEST_F(DeclarableOpsTests6, Test_StridedSlice_BP_1) {
 //    auto e = NDArrayFactory::create<int>('c', {1}, {zero});
 //    auto s = NDArrayFactory::create<int>('c', {1}, {1});
 
-    auto grad = NDArrayFactory::create<double>('c', {5,4});
+    auto grad = NDArrayFactory::create<double>('c', {5});
 
     matrix.linspace(1);
     grad.linspace(1);
@@ -264,6 +264,7 @@ TEST_F(DeclarableOpsTests6, Test_StridedSlice_BP_1) {
 
     delete result;
 }
+
 TEST_F(DeclarableOpsTests6, Test_StridedSlice_BP_2) {
     int zero = 0;
     auto matrix = NDArrayFactory::create<double>('c', {1, 2});
@@ -287,6 +288,31 @@ TEST_F(DeclarableOpsTests6, Test_StridedSlice_BP_2) {
 
     delete result;
 }
+
+TEST_F(DeclarableOpsTests6, Test_StridedSlice_BP_3) {
+    int zero = 0;
+    auto matrix = NDArrayFactory::create<float>('c', {4, 8192});
+//    auto b = NDArrayFactory::create<int>('c', {1}, {zero});
+//    auto e = NDArrayFactory::create<int>('c', {1}, {zero});
+//    auto s = NDArrayFactory::create<int>('c', {1}, {1});
+
+    auto grad = NDArrayFactory::create<double>('c', {4, 256});
+
+    matrix.linspace(1);
+    grad.linspace(1);
+
+    nd4j::ops::strided_slice_bp op;
+    auto result = op.execute({&matrix, &grad}, {}, {1, 0, 1, 0, 0, 0, 0, 0, 256, 1, 1});
+    ASSERT_EQ(Status::OK(), result->status());
+
+    auto z = result->at(0);
+    z->printShapeInfo("Output shape");
+    z->printIndexedBuffer("Output");
+    //ASSERT_TRUE(exp.equalsTo(z));
+
+    delete result;
+}
+
 TEST_F(DeclarableOpsTests6, Test_Simple_Scalar_1) {
     auto x = NDArrayFactory::create<double>('c', {1, 1}, {2.0f});
     auto exp = NDArrayFactory::create<double>('c', {1, 1}, {4.0f});