On Tue, 5 Dec 2023 17:26:06 GMT, Srinivas Vamsi Parasa <d...@openjdk.org> wrote:
>> That sounds weird. You can't check for if compiler options should be enabled >> or not inside source code files. >> >> 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. > > 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. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/16534#discussion_r1417170882
