gcd

auto eve::gcd = functor<gcd_t>

inlineconstexpr

Header file

#include <eve/module/combinatorial.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   template <integral_value T0, integral_value T1> constexpr common_value_t<T0, T1> gcd(T0 p, T1 n) noexcept; // 1
 
   // Lanes masking
   constexpr auto gcd[conditional_expr auto c](integral_value auto p, integral_value auto n)        noexcept; // 2
   constexpr auto gcd[logical_value auto m](integral_value auto p, integral_value auto n)           noexcept; // 2
}

Parameters

• p, n: integral values.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. If both p and n are zero, returns zero. Otherwise, returns the greatest common divisor of |p| and |n|.
2. The operation is performed conditionnaly.

External references

• Wikipedia: Least common multiple
• C++ standard reference: lcm

Example

#include <eve/eve.hpp>
#include <eve/module/combinatorial.hpp>
#include <iostream>
 
int main() {
   eve::wide<float> wf0([](auto i, auto c)->float{ return (i-c/2);});
   eve::wide<float> wf1([](auto i, auto )->float{ return 10*i; });
   eve::wide n{93, 25, 32, 368,  216,  43, 18, 25};
   eve::wide p{42, 30, 27, 1024, 36, 12, 51, 44};
 
   std::cout << "<- wf0 = " << wf0 << "\n";
   std::cout << "<- wf1 = " << wf1 << "\n";
   std::cout << "<- n   = " << n   << "\n";
   std::cout << "<- p   = " << p   << "\n";
 
   std::cout << "-> gcd(wf0, wf1)                = " << eve::gcd(wf0, wf1) << "\n";
   std::cout << "-> gcd[ignore_last(2)](wf0, wf1)= " << eve::gcd[eve::ignore_last(2)](wf0, wf1) << "\n";
   std::cout << "-> gcd[wf0 != -2.0f](wf0, wf1)  = " << eve::gcd[wf0 != -2.0f](wf0, wf1) << "\n";
   std::cout << "-> gcd(p, n)                    = " << eve::gcd(p, n) << "\n";
}