https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115693
Levy Hsu <admin at levyhsu dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |admin at levyhsu dot com
--- Comment #7 from Levy Hsu <admin at levyhsu dot com> ---
Looks like the problem is solved:
https://godbolt.org/z/Y7bn77bjG
#include <array>
#include <bit>
#include <cstdint>
bool compare1(const std::array<std::byte, 8> &p, std::array<std::byte, 8> r)
{
return p == r;
}
bool compare2(const std::array<char, 8> &p, std::array<char, 8> r)
{
return p == r;
}
// same assembly if you use char instead of byte
bool compare3(const std::array<std::byte, 8> &p, std::array<std::byte, 8> r)
{
return std::bit_cast<uint64_t>(p) == std::bit_cast<uint64_t>(r);
}
compiled with trunk and --std=c++20 -O3 flags produces:
compare1(std::array<std::byte, 8ul> const&, std::array<std::byte, 8ul>):
cmp QWORD PTR [rdi], rsi
sete al
ret
compare2(std::array<char, 8ul> const&, std::array<char, 8ul>):
cmp QWORD PTR [rdi], rsi
sete al
ret
compare3(std::array<std::byte, 8ul> const&, std::array<std::byte, 8ul>):
cmp QWORD PTR [rdi], rsi
sete al
ret
