std::experimental::simd<T,Abi>::simd
From cppreference.com
| simd() noexcept = default; |
(1) | (parallelism TS v2) |
| template<class U> simd( U&& value ) noexcept; |
(2) | (parallelism TS v2) |
| template<class U> simd( const simd<U, simd_abi::fixed_size<size()>>& other ) noexcept; |
(3) | (parallelism TS v2) |
| template<class G> explicit simd( G&& generator ) noexcept; |
(4) | (parallelism TS v2) |
| template<class U, class Flags> simd( const U* mem, Flags flags ); |
(5) | (parallelism TS v2) |
| simd( const simd& other ) noexcept = default; |
(6) | (parallelism TS v2) (implicitly declared) |
| simd( simd&& other ) noexcept = default; |
(7) | (parallelism TS v2) (implicitly declared) |
1) Constructs a
simd using default initialization (constructed without initializer) or value initialization (constructed with an empty initializer).2) The broadcast constructor constructs a
simd with all values initialized to value. This overload participates in overload resolution only if the conversion from U to T is value-preserving, or U is either int or unsigned int if T is an unsigned integral type.3) Constructs a
simd where the i-th element is initialized to static_cast<T>(other[i]) for all i in the range of [0, size()). This overload participates in overload resolution only if Abi is simd_abi::fixed_size<size()> and the conversion from U to T is value-preserving, and, if both U and T are integral, the integer conversion rank of T is greater than the integer conversion rank of U.4) The generator constructor constructs a
simd where the i-th element is initialized to generator(std::integral_constant<std::size_t, i>()). This overload participates in overload resolution only if simd(gen(std::integral_constant<std::size_t, i>())) is well-formed for all i in the range of [0, size()). The calls to generator are unsequenced with respect to each other. Vectorization-unsafe standard library functions may not be invoked by generator.5) The load constructor constructs a
simd where the i-th element is initialized to static_cast<T>(mem[i]) for all i in the range of [0, size()).6-7) Implicitly declared copy and move constructors. Constructs a
simd where each element is initialized from the values of the elements in other.Parameters
| value | - | the value used for initialization of all simd elements
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| other | - | another simd to copy from
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| generator | - | a function object used for initialization of each simd element
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| mem | - | a pointer into an array where [mem, mem + size()) is a valid range
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| flags | - | if of type vector_aligned_tag, the load constructor may assume mem to point to storage aligned by memory_alignment_v<simd, U>
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| Type requirements | ||
-The conversion from U to T must be value-preserving. The broadcast constructor (2) additionally allows U to be int or to be unsigned int if T is an unsigned integral type.
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-is_simd_flag_type_v<Flags> must be true.
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Example
Run this code
#include <experimental/simd> #include <iostream> namespace stdx = std::experimental; int main() { stdx::native_simd<int> a; // uninitialized a = 1; // all elements set to 1 stdx::native_simd<int> b([](int i) { return i; }); // {0, 1, 2, 3, ...} alignas(stdx::memory_alignment_v<stdx::native_simd<int>>) std::array<int, stdx::native_simd<int>::size() * 2> mem = {}; for (std::size_t i = 0; i < mem.size(); ++i) mem[i] = i & 1; stdx::native_simd<int> c(&mem[0], stdx::vector_aligned); // {0, 1, 0, 1, ...} stdx::native_simd<int> d(&mem[1], stdx::element_aligned); // {1, 0, 1, 0, ...} auto sum = a + b + c + d; for (std::size_t i = 0; i < sum.size(); ++i) std::cout << sum[i] << ' '; std::cout << '\n'; }
Possible output:
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
See also
| (parallelism TS v2) |
loads simd elements from contiguous memory (public member function) |
