E.V.E  0.1-beta

◆ mul

eve::mul = {}
inlineconstexpr

Callable object computing the mul operation.

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

Members Functions

Member Effect
operator() the mul operation
operator[] Construct a conditional version of current function object

template< value T, value ...Ts> auto operator()( T x,Ts... args ) const noexcept
requires (compatiblevalues< T, Ts > && ...);
Definition: value.hpp:31

Parameters

x, args: values.

Return value

Return the multiplication of the values.

The result type is the common compatible type of the parameters.

The call mul(x, args, ...) is equivalent to (x * args * ...) if x or one of the args is an simd value.

Warning
Although the infix notation with * is supported for two parameters, the * operator on standard scalar types is the original one and so can lead to automatic promotion.

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

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

Parameters

cond : conditional expression

Return value

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


Supported decorators

  • eve::saturated

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

    The call saturated(mul)(x, args...) computes the saturated multiplication of x and args.... The saturation is obtained in the common compatible type of the N parameters. The computation is done as if all arguments were converted to this type and the saturated multiplication applied recursively on all parameters. No overflow occurs.

  • eve::diff, eve::diff_1st, eve::diff_2nd, eve::diff_3rd, eve::diff_nth

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

    The expression diff_< N >(mul)(x,args,...) computes the partial diff of the function relative to the Nth parameter.

    If the actual parameters are \(x_1, ... x_n\) the value returned is \(\prod_{i \neq N} x_i\) if \(1\le N \le n\) otherwise 0.

    Warning
    This is only available for floating point entries.

Example

See it live on Compiler Explorer

#include <eve/function/mul.hpp>
#include <eve/wide.hpp>
#include <iostream>
int main()
{
w_t pi = {3, 2, 3, 32700}, qi = {4, 1, 1, 100};
std::cout << "---- simd" << '\n'
<< " <- pi = " << pi << '\n'
<< " <- qi = " << qi << '\n'
<< " -> mul(pi, qi) = " << eve::mul(pi, qi) << '\n'
<< " -> pi * qi = " << pi * qi << '\n';
std::int16_t xi = 100, yi = 32700;
std::cout << "---- scalar" << '\n'
<< " xi = " << xi << '\n'
<< " yi = " << yi << '\n'
<< " -> mul(xi, yi) = " << eve::mul(xi, yi) << '\n'
<< " -> xi * yi = " << xi * yi << '\n'; // C++ promotion
return 0;
}
constexpr callable_pi_ pi
Callable object computing the value.
Definition: pi.hpp:54
constexpr callable_mul_ mul
Callable object computing the mul operation.
Definition: mul.hpp:103
Wrapper for SIMD registers.
Definition: wide.hpp:65