编译过度对齐的动态分配变量时出现 icpc 错误
icpc error in compiling over-aligned dynamic allocated variables
我正在尝试用 C++ 编译代码,它使用了过度对齐的变量。如果我尝试编译以下代码(MWE)
#include <new>
#include <iostream>
int main()
{
alignas(32) double *r = new (std::align_val_t{32}) double[3];
std::cout << "alignof(r) is " << alignof(r) << '\n';
return 0;
}
如果我使用 icpx
或 g++
一切都会顺利进行(在所有情况下,标志 -std=c++17
都会提供给编译器)。但是,当使用 Intel icpc
进行编译时,出现以下错误
mwe.cpp(6): error: no instance of overloaded "operator new[]" matches the argument list
argument types are: (unsigned long, std::align_val_t)
alignas(32) double *r = new (std::align_val_t{32}) double[3];
^
/usr/include/c++/9/new(175): note: this candidate was rejected because arguments do not match
_GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
^
/usr/include/c++/9/new(141): note: this candidate was rejected because arguments do not match
_GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
^
/usr/include/c++/9/new(127): note: this candidate was rejected because mismatch in count of arguments
_GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
^
mwe.cpp(7): warning #3464: the standard "alignof" operator does not accept an expression argument (use a type instead)
std::cout << "alignof(r) is " << alignof(r) << '\n';
^
compilation aborted for mwe.cpp (code 2)
而且我不明白错误可能是什么。
我该如何解决这个问题?
icpc 似乎不符合对齐分配的标准。引用 2021.5 版本的文档:
In this release of the compiler, all that is necessary in order to get correct dynamic allocation for aligned data is to include a new header:
#include <aligned_new>
After this header is included, a new-expression for any aligned type will automatically allocate memory with the alignment of that type.
现场演示:https://godbolt.org/z/5xMqKGrTG
icpx 文档中缺少此部分:https://www.intel.com/content/www/us/en/develop/documentation/oneapi-dpcpp-cpp-compiler-dev-guide-and-reference/top.html。
我正在尝试用 C++ 编译代码,它使用了过度对齐的变量。如果我尝试编译以下代码(MWE)
#include <new>
#include <iostream>
int main()
{
alignas(32) double *r = new (std::align_val_t{32}) double[3];
std::cout << "alignof(r) is " << alignof(r) << '\n';
return 0;
}
如果我使用 icpx
或 g++
一切都会顺利进行(在所有情况下,标志 -std=c++17
都会提供给编译器)。但是,当使用 Intel icpc
进行编译时,出现以下错误
mwe.cpp(6): error: no instance of overloaded "operator new[]" matches the argument list
argument types are: (unsigned long, std::align_val_t)
alignas(32) double *r = new (std::align_val_t{32}) double[3];
^
/usr/include/c++/9/new(175): note: this candidate was rejected because arguments do not match
_GLIBCXX_NODISCARD inline void* operator new[](std::size_t, void* __p) _GLIBCXX_USE_NOEXCEPT
^
/usr/include/c++/9/new(141): note: this candidate was rejected because arguments do not match
_GLIBCXX_NODISCARD void* operator new[](std::size_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT
^
/usr/include/c++/9/new(127): note: this candidate was rejected because mismatch in count of arguments
_GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc)
^
mwe.cpp(7): warning #3464: the standard "alignof" operator does not accept an expression argument (use a type instead)
std::cout << "alignof(r) is " << alignof(r) << '\n';
^
compilation aborted for mwe.cpp (code 2)
而且我不明白错误可能是什么。 我该如何解决这个问题?
icpc 似乎不符合对齐分配的标准。引用 2021.5 版本的文档:
In this release of the compiler, all that is necessary in order to get correct dynamic allocation for aligned data is to include a new header:
#include <aligned_new>
After this header is included, a new-expression for any aligned type will automatically allocate memory with the alignment of that type.
现场演示:https://godbolt.org/z/5xMqKGrTG
icpx 文档中缺少此部分:https://www.intel.com/content/www/us/en/develop/documentation/oneapi-dpcpp-cpp-compiler-dev-guide-and-reference/top.html。