scatter

auto eve::scatter = functor<scatter_t>

inlineconstexpr

Store each element of a given SIMD value vin different memory address computed form a base SIMD compatible iterator ptr and a SIMD integral value idx used as indexes.

A call to eve::scatter(v,ptr,idx) is semantically equivalent to:

for(std::size_t i=0;i<v.size();++i)
  ptr[idx.get(i)] = v.get(i);

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
  template<simd_value T, integral_simd_value Idx, simd_compatible_ptr<T> Ptr>
  requires(T::size() == Idx::size())
  void scatter(T const& v, Ptr ptr, Idx const& idx) noexcept;
}

Parameters

• v: simd value to scatter
• ptr: Base pointer to scatter to.
• idx: Integral simd value containing the index to scatter to.

Semantic Modifiers

• Masked Call

eve::scatter can be masked using Relative conditionals to skip scattering of certain elements.

The call eve::scatter[cond](v,p,i) is semantically equivalent to:

auto m = cond.mask( as<as_logical_t<T>>{} );
for(std::size_t n=0;n<v.size();++n)
{
  if(m.get(n)) write(v.get(n),p+idx.get(n));
}

Example

#include <eve/module/core.hpp>
#include <iostream>
 
int main()
{
  float data[2*eve::wide<float>::size()] = {};
 
  eve::wide<int>   indexes  = [](auto i, auto) { return 2*i; };
  eve::wide<float> values   = [](auto i, auto) { return 1.5f * (1+i); };
 
  eve::scatter(values, data, indexes);
 
  for(auto e : data)
    std::cout << e << " ";
  std::cout << "\n";
}