[aarch64-port-dev ] RFR: 8195588: AArch64: Codegen fix after JDK-8194256

Dmitrij Pochepko dmitrij.pochepko at bell-sw.com
Wed Jan 17 13:36:40 UTC 2018

On 17.01.2018 13:14, Andrew Haley wrote:
> On 17/01/18 10:01, Ningsheng Jian wrote:
>> Please help to review this fix.
> There's insufficient explanation for anyone to review this patch.
> What exactly has been done, and why?

"shl", "ushr" and "sshr" instructions had incorrect encoding and thus 
all these instructions usages were using workaround(as part of 
http://hg.openjdk.java.net/jdk10/hs/rev/97b3293d261) to produce correct 
encoding. Shift values were modified in specific way before passing it 
to "shl", "ushr" and "sshr". It's not clear to me why this workaround 
was added instead of fixing instruction encoding. Now that instruction 
encoding was fixed by me, this workaround is no longer needed. So, 
Ningsheng removed this workaround code and codegen code became shorter 
and simplier, without any "strange-at-first-sight" constant 
manipulations(all these manipulations are now in instruction encoding 


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