text: //==================================================================================================
  /**
    Copyright 2016 NumScale SAS
  
    Distributed under the Boost Software License, Version 1.0.
    (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
  **/
  //==================================================================================================
  #include <boost/simd/function/rsqrt.hpp>
  #include <boost/simd/function/fast.hpp>
  #include <boost/simd/pack.hpp>
  #include <simd_test.hpp>
  
  namespace bs = boost::simd;
  
  template <typename T, std::size_t N, typename Env>
  void test_fast(Env& $)
  {
    using p_t = bs::pack<T, N>;
  
    T a1[N], b[N];
    for(std::size_t i = 0; i < N; ++i)
    {
      a1[i] = (i%2) ? T(2*i) : T(2*i+1);
      b[i] = bs::fast_(bs::rsqrt)(a1[i]) ;
    }
    p_t aa1(&a1[0], &a1[0]+N);
    p_t bb (&b[0], &b[0]+N);
  
    STF_ULP_EQUAL(bs::fast_(bs::rsqrt)(aa1), bb, 2048);
  }
  
  STF_CASE_TPL("Check fast rsqrt on pack" , STF_IEEE_TYPES)
  {
    static const std::size_t N = bs::pack<T>::static_size;
  
    test_fast<T, N>($);
    test_fast<T, N/2>($);
    test_fast<T, N*2>($);
  }
  
  template <typename T, std::size_t N, typename Env>
  void test(Env& $)
  {
    namespace bs = boost::simd;
    using p_t = bs::pack<T, N>;
  
    T a1[N], b[N];
    for(std::size_t i = 0; i < N; ++i)
    {
      a1[i] = (i%2) ? T(2*i) : T(2*i+1);
      b[i]  = bs::rsqrt(a1[i]) ;
    }
    p_t aa1(&a1[0], &a1[0]+N);
    p_t bb (&b[0], &b[0]+N);
  
    STF_ULP_EQUAL(bs::rsqrt(aa1), bb, 1);
  }
  
  STF_CASE_TPL("Check rsqrt on pack" , STF_IEEE_TYPES)
  {
    static const std::size_t N = bs::pack<T>::static_size;
  
    test<T, N>($);
    test<T, N/2>($);
    test<T, N*2>($);
  }
  