Please review the below change which removes *most* uses of the register keyword/storage class specifier. Bug: https://bugs.openjdk.java.net/browse/JDK-8207011 <https://bugs.openjdk.java.net/browse/JDK-8207011> Webrev: http://cr.openjdk.java.net/~mikael/webrevs/8207011/webrev.01/open/webrev/ <http://cr.openjdk.java.net/~mikael/webrevs/8207011/webrev.01/open/webrev/> * Background (from the bug) The C/C++ register keyword/storage class specifier may have made a difference many moons ago, but the C++11 standard deprecated it, and starting with C++17 it is a reserved keyword. Some compilers emit deprecation warnings even when targeting earlier C++ standards such as C++14. * Commentary The one case where the register keyword remains is when compiling (effectively) inline assembly with gcc, patterns like: address os::current_stack_pointer() { … #else // gcc register void *esp __asm__ (SPELL_REG_SP); return (address) esp; #endif } Removing the register keyword here breaks the code, and gcc does *not* complain about using it for these patterns, so I chose to leave it there. An alternative to that would be to always use the “clang” style mov instruction. I know there is another thread[1] discussing how to move forward with the current_stack_pointer on clang 4.0. I’ll keep my eyes on that to make sure we don’t collide (and cc:ing Martin for good luck). Would appreciate some help from the respective porting folks to verify the aix/ppc/s390 changes. Cheers, Mikael [1] http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2018-July/029099.... <http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2018-July/029099.html>