Hi Martin, this makes sense. This is the right way to force alignment. I do not like the platform code in the shared file but do not think this is a big deal.
+#if defined (_WIN32) && defined (_MSC_VER) Why do you think we need _MSC_VER too? Is OpenJDK on Windows even buildable with anything other than VC++? Cheers, Thomas On Mon, Dec 2, 2019 at 4:14 PM Doerr, Martin <martin.do...@sap.com> wrote: > Hi, > > I'd like to propose a fix for an old issue on 32 bit Windows (also for an > 11u backport): > https://bugs.openjdk.java.net/browse/JDK-8220348 > > Some jdk native methods use jni_SetLongArrayRegion with a stack allocated > buffer. > jni_SetLongArrayRegion uses Copy::conjoint_jlongs_atomic which requires > jlongs to be 8 byte aligned (asserted). > However, Windows 32 bit only uses 4 byte alignment for jlong arrays by > default. > I found such issues in the following files: > src/java.prefs/windows/native/libprefs/WindowsPreferences.c > src/java.security.jgss/share/native/libj2gss/GSSLibStub.c > I suggest to use __declspec(align(8)) there. > > Webrev: > http://cr.openjdk.java.net/~mdoerr/8220348_ntintel_stack_align/webrev.00/ > Please review. > > I think using 8 byte alignment is not a disadvantage for 64 bit. > > I guess there are still people interested in this platform with jdk14. > Otherwise I could contribute it as 11u only fix. > > Is there a better way to force 8 byte alignment for jlongs or jlong arrays > on stack? > Best regards, > Martin > >
