update code

Author: wanghaox

paddle/operators/iou_similarity_op.cu

@@ -18,4 +18,5 @@ limitations under the License. */
 namespace ops = paddle::operators;
 REGISTER_OP_CUDA_KERNEL(
     iou_similarity,
-    ops::IOUSimilarityKernel<paddle::platform::CUDADeviceContext, float>);
+    ops::IOUSimilarityKernel<paddle::platform::CUDADeviceContext, float>,
+    ops::IOUSimilarityKernel<paddle::platform::CUDADeviceContext, double>);

paddle/operators/iou_similarity_op.h

@@ -46,7 +46,7 @@ struct IOUSimilarityFunctor {
     T y_min1 = x_[row_id * 4 + 1];
     T x_max1 = x_[row_id * 4 + 2];
     T y_max1 = x_[row_id * 4 + 3];
-    for (int i = 0; i < cols_; ++i) {
+    for (size_t i = 0; i < cols_; ++i) {
       T x_min2 = y_[i * 4];
       T y_min2 = y_[i * 4 + 1];
       T x_max2 = y_[i * 4 + 2];