Implement gather with hip backend.
ADD
thrust/system/hip/detail/gather.h
+/******************************************************************************
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of the NVIDIA CORPORATION nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ******************************************************************************/
+#pragma once
+
+
+#if THRUST_DEVICE_COMPILER == THRUST_DEVICE_COMPILER_HCC
+#include <thrust/system/hip/detail/transform.h>
+#include <thrust/iterator/permutation_iterator.h>
+
+BEGIN_NS_THRUST
+namespace hip_rocprim {
+
+template <class Derived,
+ class MapIt,
+ class ItemsIt,
+ class ResultIt>
+ResultIt __host__ __device__
+gather(execution_policy<Derived>& policy,
+ MapIt map_first,
+ MapIt map_last,
+ ItemsIt items,
+ ResultIt result)
+{
+ return hip_rocprim::transform(policy,
+ thrust::make_permutation_iterator(items, map_first),
+ thrust::make_permutation_iterator(items, map_last),
+ result,
+ identity());
+}
+
+
+template <class Derived,
+ class MapIt,
+ class StencilIt,
+ class ItemsIt,
+ class ResultIt,
+ class Predicate>
+ResultIt __host__ __device__
+gather_if(execution_policy<Derived>& policy,
+ MapIt map_first,
+ MapIt map_last,
+ StencilIt stencil,
+ ItemsIt items,
+ ResultIt result,
+ Predicate predicate)
+{
+ return hip_rocprim::transform_if(policy,
+ thrust::make_permutation_iterator(items, map_first),
+ thrust::make_permutation_iterator(items, map_last),
+ stencil,
+ result,
+ identity(),
+ predicate);
+}
+
+template <class Derived,
+ class MapIt,
+ class StencilIt,
+ class ItemsIt,
+ class ResultIt>
+ResultIt __host__ __device__
+gather_if(execution_policy<Derived>& policy,
+ MapIt map_first,
+ MapIt map_last,
+ StencilIt stencil,
+ ItemsIt items,
+ ResultIt result)
+{
+ return hip_rocprim::gather_if(policy,
+ map_first,
+ map_last,
+ stencil,
+ items,
+ result,
+ identity());
+}
+
+
+} // namespace hip_rocprim
+END_NS_THRUST
+
+#endif

Implement gather with hip backend.