ldexp

eve::ldexp = functor<ldexp_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto ldexp(floating_value auto x, integral_value N)                           noexcept; // 1
 
   // Lanes masking
   constexpr auto ldexp[conditional_expr auto c](floating_value auto x), integral_value N) noexcept; // 2
   constexpr auto ldexp[logical_value auto m](floating_value auto x, integral_value N)     noexcept; // 2
 
   // Semantic options
   constexpr auto abs[pedantic](floating_value auto x, integral_value N)                   noexcept; // 3
}

Parameters

• x: value.
• c: Conditional expression masking the operation.
• n: integral value argument.
• m: Logical value masking the operation.

Return value

1. The value of $\textstyle x 2^n$ is returned.
2. The operation is performed conditionnaly.
3. Takes extra care to handling limit values.
   • If x is $\pm0$, it is returned, unmodified.
   • If x is $\pm\infty$, it is returned, unmodified.
   • If n is 0, then x is returned, unmodified.
   • If x is NaN, NaN is returned.

External references

• C++ standard reference

Example

// revision 0
#include <eve/module/core.hpp>
#include <iostream>
 
int main()
{
  eve::wide wf0{0.0, 1.0, 2.0, 3.0, -1.0, -2.0, -3.0, -4.0};
  eve::wide wi0{0, 1, 2, 3, -1, -2, -3, -4};
  eve::wide wi1{0, 1, 2, 3, 4, 5, 6, 7};
 
  std::cout << "<- wf0                      = " << wf0 << "\n";
  std::cout << "<- wi0                      = " << wi0 << "\n";
  std::cout << "<- wi1                      = " << wi1 << "\n";
 
  std::cout << "-> ldexp(wf0, wi0)                 = " << eve::ldexp(wf0, wi0) << "\n";
  std::cout << "-> ldexp[ignore_last(2)](wf0, wi0) = " << eve::ldexp[eve::ignore_last(2)](wf0, 2*wi0) << "\n";
  std::cout << "-> ldexp[wf0 != 0](wf0, wi0)       = " << eve::ldexp[wf0 != 0](wf0, wi0) << "\n";
  std::cout << "-> ldexp(wf0, wi1)                 = " << eve::ldexp(wf0, wi1) << "\n";
  std::cout << "-> ldexp[ignore_last(2)](wf0, wi1  = " << eve::ldexp[eve::ignore_last(2)](wf0, wi1) << "\n";
  std::cout << "-> ldexp[wi1 != 2](wf0, wi1)        = " << eve::ldexp[wi1 != 2](wf0, wi1) << "\n";
}