std::experimental::simd<T,Abi>::copy_from
From cppreference.com
< cpp | experimental | simd | simd
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Experimental
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals TS v2)
Library fundamentals 3 (library fundamentals TS v3)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Extensions for concurrency 2 (concurrency TS v2)
Concepts (concepts TS)
Ranges (ranges TS)
Reflection (reflection TS)
Mathematical special functions (special functions TR)
Extensions for parallelism v2
Parallel exceptions
Additional execution policies
Algorithms
Task blocks
std::experimental::simd
Member functions
Non-member functions
template< class U, class Flags >
void copy_from( const U* mem, Flags flags );
(parallelism TS v2)
void copy_from( const U* mem, Flags flags );
The load function replaces all elements of a simd such that the ith element is assigned with static_cast<T>(mem[i]) for all i in the range of [0, size() ).
[edit] 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.
[edit] 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