/* * Copyright 2008-2012 NVIDIA Corporation * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <thrust/detail/config.h> #include <thrust/system/detail/generic/adjacent_difference.h> #include <thrust/adjacent_difference.h> #include <thrust/functional.h> #include <thrust/iterator/iterator_traits.h> #include <thrust/detail/temporary_array.h> #include <thrust/transform.h> namespace thrust { namespace system { namespace detail { namespace generic { template <typename DerivedPolicy, class InputIterator, class OutputIterator> OutputIterator adjacent_difference(thrust::execution_policy<DerivedPolicy> &exec, InputIterator first, InputIterator last, OutputIterator result) { typedef typename thrust::iterator_traits<InputIterator>::value_type InputType; thrust::minus<InputType> binary_op; return thrust::adjacent_difference(exec, first, last, result, binary_op); } // end adjacent_difference() template <typename DerivedPolicy, class InputIterator, class OutputIterator, class BinaryFunction> OutputIterator adjacent_difference(thrust::execution_policy<DerivedPolicy> &exec, InputIterator first, InputIterator last, OutputIterator result, BinaryFunction binary_op) { typedef typename thrust::iterator_traits<InputIterator>::value_type InputType; if(first == last) { // empty range, nothing to do return result; } else { // an in-place operation is requested, copy the input and call the entry point // XXX a special-purpose kernel would be faster here since // only block boundaries need to be copied thrust::detail::temporary_array<InputType, DerivedPolicy> input_copy(exec, first, last); *result = *first; thrust::transform(exec, input_copy.begin() + 1, input_copy.end(), input_copy.begin(), result + 1, binary_op); } return result + (last - first); } } // end namespace generic } // end namespace detail } // end namespace system } // end namespace thrust