std::assume_aligned 定义于头文件<memory> template<std::size_tN,classT> [[nodiscard]]constexprT*assume_aligned(T*ptr); (C++20 起) 告知编译器ptr所指向的对象至少对齐到N。实现可用此信息生成更高效的代码,但仅会对通过assume_aligned的返回值进行的访问做此假设。
为确保程序能从以 assume_aligned 启用的优化受益,最好通过其返回值访问对象: void f(int* p) { int* p1 = std::assume_aligned<256>(p); // 用 p1 而非 p,以确保从对齐假设受益。 // 然而,若 p 未对齐则程序有未定义行为,无关乎是否使用 p1。 }...
似乎assume_aligned在RHEL的GCC中不被支持(它还没有被反向移植到上游的GCC -4_8分支，并且在Ubuntu14....
__builtin_assume_aligned只是gcc的一个提示，即指针已经对齐，因此它通常可以对以下代码进行向量化;它不...
在 C++ 标准库中，std::transform() 是一个非常有用的算法函数，它能够将给定范围中的每个元素进行...
When ASSUME_ALIGNED Directive is used on a pointer it specifies the pointer is alligned but not the data to which it points. Is there a syntax which can be used to specify the data to which a pointer points is aligned? I know I can work around this by calling a subroutine with the ...
Consider: static inline void atomic16_set(__int128 *ptr, __int128 val) { __int128_t *ptr_align = __builtin_assume_aligned(ptr, 16); __int128_t old; __sync_bool_compare_and_swap_16(ptr_align, old, 0); } On s390, this causes a warning from...
__builtin_assume_aligned只是gcc的一个提示，即指针已经对齐，因此它通常可以对以下代码进行向量化;它不...
The "assume_aligned" directive is only allowed to reference dummy arguments. What is the declaration for your array pnm? If this is a local array or one declared in a module, and you want to force/enforce a certain alignment, you can use !dir$ align : 64 :: pnm --Lorri Translate 0...
aIt is important to note in light of the discussion above, that virtually all of the conceptual and empirical efforts to identify horizontally aligned HR practices have used generic HR practices such as "pay for performance" or "valid employment tests." These approaches assume that the generic pr...