Vc/common/interleave.h

0001 /*  This file is part of the Vc library. {{{
0002 Copyright © 2014-2015 Matthias Kretz <kretz@kde.org>
0003
0004 Redistribution and use in source and binary forms, with or without
0005 modification, are permitted provided that the following conditions are met:
0006     * Redistributions of source code must retain the above copyright
0007       notice, this list of conditions and the following disclaimer.
0008     * Redistributions in binary form must reproduce the above copyright
0009       notice, this list of conditions and the following disclaimer in the
0010       documentation and/or other materials provided with the distribution.
0011     * Neither the names of contributing organizations nor the
0012       names of its contributors may be used to endorse or promote products
0013       derived from this software without specific prior written permission.
0014
0015 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
0016 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
0017 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
0018 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
0019 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
0020 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
0021 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
0022 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
0023 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
0024 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0025
0026 }}}*/
0027
0028 #ifndef VC_COMMON_INTERLEAVE_H_
0029 #define VC_COMMON_INTERLEAVE_H_
0030
0031 #include "macros.h"
0032
0033 namespace Vc_VERSIONED_NAMESPACE
0034 {
0035 /** \ingroup Utilities
0036  Interleaves the entries from \p a and \p b into two vectors of the same type. The order
0037  in the returned vector contains the elements `a[0], b[0], a[1], b[1], a[2], b[2], a[3],
0038  b[3], ...`.
0039
0040 Example:
0041 \code
0042 Vc::SimdArray<int, 4> a = { 1, 2, 3, 4 };
0043 Vc::SimdArray<int, 4> b = { 9, 8, 7, 6 };
0044 std::tie(a, b) = Vc::interleave(a, b);
0045 std::cout << a << b;
0046 // prints:
0047 // <1 9 2 8><3 7 4 6>
0048 \endcode
0049
0050  \param a input vector whose data will appear at even indexes in the output
0051  \param b input vector whose data will appear at odd indexes in the output
0052  \return two vectors with data from \p a and \p b interleaved
0053  */
0054 template <typename V, typename = enable_if<Traits::is_simd_vector<V>::value>>
0055 std::pair<V, V> interleave(const V &a, const V &b)
0056 {
0057     return {a.interleaveLow(b), a.interleaveHigh(b)};
0058 }
0059 }  // namespace Vc
0060
0061 #endif  // VC_COMMON_INTERLEAVE_H_
0062
0063 // vim: foldmethod=marker