bitofsign

eve::bitofsign = functor<bitofsign_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto bitofsign(value auto x)                          noexcept; // 1
 
   // Lanes masking
   constexpr auto bitofsign[conditional_expr auto c](value auto x) noexcept; // 2
   constexpr auto bitofsign[logical_value auto m](value auto x)    noexcept; // 2
}

Parameters

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

Return value

1. The value of the bit of sign is returned.
2. The operation is performed conditionnaly.

Note

• bitofsign does NOT return a logical value
• In particular, take care that for floating real values bitofsign does NOT return a logical value that can be tested, but mzero(as(x)) if x is negative and zero(as(x)) if x is positive, which both satisfy the eve::is_eqz predicate.
• If you want to test if the bit of sign is set is_negative is the right function to call.

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 wu0{0u, 1u, 2u, 3u, 4u, 5u, 6u, 7u};
 
  std::cout << "<- wf0                            = " << wf0 << "\n";
  std::cout << "<- wi0                            = " << wi0 << "\n";
  std::cout << "<- wu0                            = " << wu0 << "\n";
                                                  
  std::cout << "-> bitofsign(wf0)                 = " << eve::bitofsign(wf0) << "\n";
  std::cout << "-> bitofsign[ignore_last(2)](wf0) = " << eve::bitofsign[eve::ignore_last(2)](wf0) << "\n";
  std::cout << "-> bitofsign[wf0 != 0](wf0)       = " << eve::bitofsign[wf0 != 0](wf0) << "\n";
  std::cout << "-> bitofsign(wu0)                 = " << eve::bitofsign(wu0) << "\n";
  std::cout << "-> bitofsign[ignore_last(2)](wu0) = " << eve::bitofsign[eve::ignore_last(2)](wu0) << "\n";
  std::cout << "-> bitofsign[wu0 != 0](wu0)       = " << eve::bitofsign[wu0 != 0](wu0) << "\n";
  std::cout << "-> bitofsign(wi0)                 = " << eve::bitofsign(wi0) << "\n";
  std::cout << "-> bitofsign[ignore_last(2)](wi0) = " << eve::bitofsign[eve::ignore_last(2)](wi0) << "\n";
  std::cout << "-> bitofsign[wi0 != 0](wi0)       = " << eve::bitofsign[wi0 != 0](wi0) << "\n";
}