Currently, EGPR register save ordering[1] does not comply with the precomputed stack offsets[2], this leads to incorrect register value reconstruction and various runtime clients using callee's RegisterMap like GC root set enumeration, de-optimization object reconstruction experience incorrectness issues or hit exception failure, etc.

The issue was discovered during our internal validation of SPECjvm2008 worklets with -XX:+UseAPX runtime flag using Intel SDE tool.

[1] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp#L268
[2] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp#L105