[11u] RFR 8206895: aarch64: rework error-prone cmp instuction

[Andrew Haley]

On 3/22/21 3:08 PM, Dmitry Chuyko wrote:
> Hello,
> 
> Original bug: https://bugs.openjdk.java.net/browse/JDK-8206895
> 
> Original patch applies with minor fuzz and requires minor adjustments: 
> few rejected changes in macroAssembler_aarch64.cpp and 
> stubGenerator_aarch64.cpp were recreated -- all because of already 
> ported stuff [1][2][3][4].

I'm tempted to say no to this one, because it's too intrusive. If
that means a ton of enhancements such as JDK-8229351 are more difficult
to backport, is that a bad thing? Otherwise we're basically porting all
of the AArch64 back end from head to 11u.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671