std::experimental::simd<T,Abi>::copy_from

 

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std::experimental::simd

Member functions
simd copy_from copy_to size	operator!operator~operator+operator-	operator[] operator++operator--
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operator+operator-operator*operator/operator%operator&operator|operator^operator<<operator>>	operator+=operator-=operator*=operator/=operator%=operator&=operator|=operator^=operator<<=operator>>=	operator==operator!=operator>=operator<=operator>operator<

 

template< class U, class Flags > void copy_from( const U* mem, Flags flags );		(parallelism TS v2)

The load function replaces all elements of a simd such that the i^th element is assigned with static_cast<T>(mem[i]) for all i in the range of [​0​, size()).

Parameters

mem	-	a pointer into an array where [mem, mem + size()) is a valid range
flags	-	if of type vector_aligned_tag, the load constructor may assume mem to point to storage aligned by memory_alignment_v<simd, U>
Type requirements
- U must be a vectorizable type.
- is_simd_flag_type_v<Flags> must be true.

Example

Run this code

#include <cstddef>
#include <experimental/simd>
#include <iostream>
#include <numeric>
namespace stdx = std::experimental;
 
void print(auto const& a)
{
    for (std::size_t i{}; i != std::size(a); ++i)
        std::cout << a[i] << ' ';
    std::cout << '\n';
}
 
int main()
{
    alignas(stdx::memory_alignment_v<stdx::native_simd<int>>)
        std::array<int, stdx::native_simd<int>::size() * 2> mem = {};
    std::iota(mem.begin(), mem.end(), 0);
    print(mem);
 
    stdx::native_simd<int> a; / uninitialized
 
    a.copy_from(&mem[0], stdx::vector_aligned);
    print(a);
 
    a.copy_from(&mem[1], stdx::element_aligned); / vector_aligned would likely crash
    print(a);
}

Possible output:

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0 1 2 3 4 5 6 7
1 2 3 4 5 6 7 8

See also

memory_alignment (parallelism TS v2)	obtains an appropriate alignment for vector_aligned (class template)
copy_to (parallelism TS v2)	stores simd elements to contiguous memory (public member function)
(constructor) (parallelism TS v2)	constructs a simd object (public member function)

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