On Wed, 6 Dec 2023 11:59:19 GMT, Magnus Ihse Bursie <i...@openjdk.org> wrote:
>> Hi Magnus (@magicus), >> >>> Are you saying that when compiling with GCC 6, it will just silently ignore >>> `-std=c++17`? I'd have assumed that it printed a warning or error about an >>> unknown or invalid option, if C++17 is not supported. >> >> The GCC complier for versions 6 (and even 5) silently ignores the flag >> `-std=c++17`. It does not print any warning or error. I tested it with a toy >> C++ program and also by building OpenJDK using GCC 6. >> >>> You can't check for if compiler options should be enabled or not inside >>> source code files. >> >> what I meant was, there are #ifdef guards using predefined macros in the >> C++ source code to check for GCC version and make the simdsort code >> available for compilation or not based on the GCC version >> >> >> // src/java.base/linux/native/libsimdsort/simdsort-support.hpp >> #if defined(_LP64) && (defined(__GNUC__) && ((__GNUC__ > 7) || ((__GNUC__ == >> 7) && (__GNUC_MINOR__ >= 5)))) >> #define __SIMDSORT_SUPPORTED_LINUX >> #endif >> >> >> >> //src/java.base/linux/native/libsimdsort/avx2-linux-qsort.cpp >> #include "simdsort-support.hpp" >> #ifdef __SIMDSORT_SUPPORTED_LINUX >> <simdsort functions> >> #endif > > Okay, then I guess I am fine with this. Thank you Magnus! ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/16534#discussion_r1417707661
