Fixing a bug in strided slice. The op was not handling negative indices correctly.

PiperOrigin-RevId: 193245539

1 files changed, 11 insertions, 11 deletions

diff --git a/tensorflow/contrib/lite/kernels/strided_slice.cc b/tensorflow/contrib/lite/kernels/strided_slice.cc
index e6d5c300dc..40ac436b7d 100644
--- a/tensorflow/contrib/lite/kernels/strided_slice.cc
+++ b/tensorflow/contrib/lite/kernels/strided_slice.cc
@@ -87,6 +87,8 @@ inline int32_t ClampedIndex(int32_t index, int dim, bool pos_stride) {
                           std::min(std::max(index, -dim), dim - 1), dim));
 }
 
+// TODO(b/77971377) this logic should be removed, as it's a duplication of
+// StartForAxis() & StopForAxis() in kernels/internal/reference/reference_ops.h
 inline int32_t GetBeginValueAtIndex(StridedSliceContext* op_context, int idx) {
   const int dim = op_context->input->dims->data[idx];
   const bool pos_stride = GetTensorData<int32_t>(op_context->strides)[idx] > 0;
@@ -188,8 +190,8 @@ TfLiteStatus Eval(TfLiteContext* context, TfLiteNode* node) {
   std::vector<int32_t> strides;
 
   for (int idx = op_context.dims - 1; idx >= 0; --idx) {
-    starts.emplace_back(GetBeginValueAtIndex(&op_context, idx));
-    stops.emplace_back(GetEndValueAtIndex(&op_context, idx));
+    starts.emplace_back(GetTensorData<int32_t>(op_context.begin)[idx]);
+    stops.emplace_back(GetTensorData<int32_t>(op_context.end)[idx]);
     strides.emplace_back(GetTensorData<int32_t>(op_context.strides)[idx]);
   }
 
@@ -202,15 +204,13 @@ TfLiteStatus Eval(TfLiteContext* context, TfLiteNode* node) {
   int begin_mask =
       ReverseMaskBits(op_context.params->begin_mask, op_context.dims);
   int end_mask = ReverseMaskBits(op_context.params->end_mask, op_context.dims);
-  int shrink_axis_mask =
-      ReverseMaskBits(op_context.params->shrink_axis_mask, op_context.dims);
-
-#define TF_LITE_STRIDED_SLICE(kernel_type, data_type)                          \
-  kernel_type::StridedSlice(                                                   \
-      GetTensorData<data_type>(op_context.input),                              \
-      GetTensorDims(op_context.input), begin_mask, end_mask, shrink_axis_mask, \
-      starts, stops, strides, GetTensorData<data_type>(op_context.output),     \
-      GetTensorDims(op_context.output))
+
+#define TF_LITE_STRIDED_SLICE(kernel_type, data_type)                    \
+  kernel_type::StridedSlice(GetTensorData<data_type>(op_context.input),  \
+                            GetTensorDims(op_context.input), begin_mask, \
+                            end_mask, starts, stops, strides,            \
+                            GetTensorData<data_type>(op_context.output), \
+                            GetTensorDims(op_context.output))
 
   switch (op_context.input->type) {
     case kTfLiteFloat32: