percona/percona-server
cmake/compiler_features.cmake
:68
CHECK_CXX_SOURCE_RUNS("
#include <cstdint>
int main() {
uint64_t a = 0xffffFFFFffffFFFF;
__uint128_t b = __uint128_t(a) * a;
a = static_cast<uint64_t>(b >> 64);
return 0;
}
" HAVE_UINT128_EXTENSION)