E.V.E
v2022.03.00

◆ ceil

eve::ceil = {}
inlineconstexpr

Computes the smallest integer not less than the input.

Defined in Header

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
template< eve::value T >
T ceil(T x) noexcept;
}
constexpr callable_ceil_ ceil
Computes the smallest integer not less than the input.
Definition: ceil.hpp:80
Definition: all_of.hpp:22

Parameters

Return value

The smallest integer not less than x.

The standard proposes 4 rounding modes namely: FE_TONEAREST, FE_DOWNWARD, FE_UPWARD, FE_TOWARDZERO. This function object implements the FE_UPWARD version.

For complex inputs the ceil operation is applied to both real and imaginary parts.

Example

#include <eve/module/core.hpp>
#include <eve/wide.hpp>
#include <iostream>
int main()
{
wide_ft pf = {-1.0f, -1.3f, -1.5f, -1.7f, 2.0f, 2.3f, 2.5f, 2.7f};
std::cout << "---- simd" << '\n'
<< "<- pf = " << pf << '\n'
<< "-> ceil(pf) = " << eve::ceil(pf) << '\n';
float xf = -32.768f;
std::cout << "---- scalar" << '\n'
<< "<- xf = " << xf << '\n'
<< "-> ceil(xf) = " << eve::ceil(xf) << '\n';
return 0;
}
Wrapper for SIMD registers.
Definition: wide.hpp:65

Semantic Modifiers

  • Masked Call

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

    Example

    #include <eve/module/core.hpp>
    #include <eve/wide.hpp>
    #include <iostream>
    int main()
    {
    wide_ft pf = {-1.0f, -1.3f, -1.5f, -1.7f, 2.0f, 2.3f, 2.5f, 2.7f};
    std::cout << "---- simd" << '\n'
    << "<- pf = " << pf << '\n'
    << "-> ceil[pf > -1.5f](pf) = " << eve::ceil[pf > -1.5f](pf) << '\n';
    return 0;
    }
  • eve::tolerant

    The expression tolerant(ceil)(x, tol) computes a tolerant ceil value for x, where x must be a floating value.

    • If tol is a floating value, computes the floor with a tolerance tol using Hagerty's FL5 function.
    • If tol is an integral value n, computes the floor of the next nth representable value in the x type.
    • If tol is omitted, the tolerance is taken to 3 times the machine \(\epsilon\) in the x type (3*eve::eps (eve::as (x))).
    #include <eve/module/core.hpp>
    #include <eve/wide.hpp>
    #include <iostream>
    #include <iomanip>
    int main()
    {
    wide_ft pf = {-1.0f, -1.3f, -1.5f, -1.7f, 2.0f, 2.3f, 2.5f, 2.7f};
    pf += 3*eve::eps(eve::as<float>());
    std::cout << "---- simd" << std::setprecision(8) << '\n'
    << "<- pf = " << pf << '\n'
    << "-> ceil(pf) = " << eve::ceil(pf) << '\n'
    << "-> tolerant(ceil)(pf) = " << eve::tolerant(eve::ceil)(pf) << '\n'
    << "-> tolerant(ceil)(pf, 1) = " << eve::tolerant(eve::ceil)(pf, 1) << '\n';
    return 0;
    }
    constexpr tolerant_type const tolerant
    Higher-order Callable Object imbuing a less strict semantic onto other Callable Objects.
    Definition: fuzzy.hpp:147
    Lightweight type-wrapper.
    Definition: as.hpp:29