NAME¶

std::experimental::simd::copy_from - std::experimental::simd::copy_from

Synopsis¶

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

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