sub

eve::sub = {}

inlineconstexpr

Computes the sum of its arguments.

Defined in Header

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   template< eve::value... Ts>
   eve::common_compatible_t<Ts ...> sub(Ts ... xs) noexcept;
}

Parameters

• ... xs : real or complex arguments.

Return value

If the arguments are \((x_i)_{0\le i\le n}\) The value of \(x_0-\sum_1^n x_i\) is returned.

Example

#include <eve/module/core.hpp>
#include <eve/wide.hpp>
#include <iostream>
 
int main()
{
  using w_t = eve::wide<std::int16_t, eve::fixed<4>>;
  w_t pi = {3, 2, -32700, 32700}, qi = {4, 1, 100, -100};
  using wf_t = eve::wide<float, eve::fixed<4>>;
  wf_t pf = {3, 2.5, -32.7, 1327.43}, qf = {-4.2, -1.5, 100.834, -10.02};
 
  std::cout << "---- simd" << '\n'
            << " <- pi          = " << pi << '\n'
            << " <- qi          = " << qi << '\n'
            << " -> sub(pi, qi) = " << eve::sub(pi, qi) << '\n'
            << " -> pi - qi     = " << pi - qi << '\n'
            << " -> pf - qf     = " << pf - qf << '\n';
 
  std::int16_t xi = 100, yi = 32700;
 
  std::cout << "---- scalar" << '\n'
            << " <- xi          = " << xi << '\n'
            << " <- yi          = " << yi << '\n'
            << " -> sub(xi, yi) = " << eve::sub(xi, yi) << '\n'
            << " -> xi - yi     = " << xi - yi << '\n'; // C++ promotion to int
  return 0;
}

Semantic Modifiers

• Masked Call

  The call eve::sub[mask](x, ...) provides a masked version of sub which is equivalent to if_else(mask, sub(x, ...), x)

  Example

  #include <eve/module/core.hpp>
  #include <eve/wide.hpp>
  #include <iostream>
   
  int main()
  {
    using w_t = eve::wide<std::int16_t, eve::fixed<4>>;
    w_t pi = {3, 2, -32700, 32700}, qi = {4, 1, 100, -100};
   
    std::cout << "---- simd" << '\n'
              <<  " -> sub[pi > qi](pi, qi) = " << eve::sub[pi > qi](pi, qi) << '\n'; 
    return 0;
  }

• eve::saturated

  The call eve::saturated(eve::sub)(...) computes a saturated version of eve::sub.

  Take care that for signed integral entries this kind of operation is highly order dependant. We do not advise to use it for more than 2 parameters.

  Example

  #include <eve/module/core.hpp>
  #include <eve/wide.hpp>
  #include <iostream>
   
  int main()
  {
    using w_t = eve::wide<std::int16_t, eve::fixed<4>>;
    w_t pi = {3, 2, -32700, 32700}, qi = {4, 1, 100, -100};
   
    std::cout << "---- simd" << '\n'
              << " <- pi                      = " << pi << '\n'
              << " <- qi                      = " << qi << '\n'
              <<  " -> saturated(sub)(pi, qi) = " << eve::saturated(eve::sub)(pi, qi) << '\n';
   
     return 0;
  }