E.V.E  0.1-beta

◆ log2

eve::log2 = {}
inlineconstexpr

Callable object computing the base 2 logarithm: \(\log_2 x\).

Required header: #include <eve/function/log2.hpp>

Members Functions

Member Effect
operator() the computation of the base 2 logarithm
operator[] Construct a conditional version of current function object

auto operator()( floating_value auto x ) const noexcept;
Definition: value.hpp:83

Parameters

x: floating real value.

Return value

Returns the elementwise the base 2 logarithm of x In particular, for floating inputs:

  • If the element is \(\pm0\), \(-\infty\) is returned.
  • If the element is \(1\), \(+0\) is returned.
  • If the element is \(\infty\), \(\infty\) is returned.
  • If the element is less than 0, NaN is returned.

auto operator[]( conditional_expression auto cond ) const noexcept;

Higher-order function generating a masked version of eve::log2

Parameters

cond : conditional expression

Return value

A Callable object so that the expression log2[cond](x, ...) is equivalent to if_else(cond,log2(x, ...),x)


Supported decorators

Example

See it live on Compiler Explorer

#include <eve/function/log2.hpp>
#include <eve/wide.hpp>
#include <eve/constant/inf.hpp>
#include <eve/constant/nan.hpp>
#include <iostream>
int main()
{
wide_ft pf = {0.0f, -0.0f, -1.0f, 1.0f, 2.0f,
std::cout << "---- simd" << '\n'
<< "<- pf = " << pf << '\n'
<< "-> log2(pf) = " << eve::log2(pf) << '\n';
float xf = 1.0f;
std::cout << "---- scalar" << '\n'
<< "<- xf = " << xf << '\n'
<< "-> log2(xf) = " << eve::log2(xf) << '\n';
return 0;
}
constexpr callable_nan_ nan
Callable object computing the nan value.
Definition: nan.hpp:52
constexpr callable_inf_ inf
Callable object computing the infinity ieee value.
Definition: inf.hpp:54
constexpr callable_log2_ log2
Callable object computing the base 2 logarithm: .
Definition: log2.hpp:83
Lightweight type-wrapper.
Definition: as.hpp:29
Wrapper for SIMD registers.
Definition: wide.hpp:65