[11] RFR: 8145665: Make UseSSE an x86 specific option and cleanup its usage in shared code

[Vladimir Kozlov]

Hi Rahul

Good job. This should be tested and reviewed by our colleges in SAP and 
RH on their platforms.

I surprise that the flag is not reset to 0 on Aarch64, s390 and our arm 
ports.

I am concern about changes in c1_LinearScan.cpp. Before changes first 
block was executed for S390 and 'else' block was executed for other 
platforms.

Also we should remove code associated with Use24BitFP (as separate RFE). 
It should not be used anymore because it was for old x64 CPUs where FPU 
was used for float operations. I think it will be hard to find 
processors without SSE now. I hope other architectures do not use it.

Thanks,
Vladimir

On 4/5/18 8:06 AM, Rahul Raghavan wrote:
> Hi,
> 
> JBS - https://bugs.openjdk.java.net/browse/JDK-8145665
> 
> Request help to review, confirm if 8145665 requirement can be achieved 
> with following proposed changes.
> 
> webrev.00 - http://cr.openjdk.java.net/~rraghavan/8145665/webrev.00/
> 
> 
> -- UseSSE option moved from globals.hpp to globals_x86.hpp,
> usages in shared code guarded for x86 wherever missing.
> 
> -- Also found two tests required to use -XX:UseSSE option.
> (Test6579789.java, Test6855215.java)
> (confirmed the UseSSE requirement for these tests from the old related 
> bugs notes.)
> So added @requires for the tests to prevent from running and failing in 
> Sparc after 8145665 changes.
> 
> -- No issues with local builds, hs-tier1,hs-tier2 testing, 
> pre-integeration testing in progress
> 
> -- I will also work for other related task - JDK-8038595
> 'Using platform specific flags may cause VM crash'
> 
> 
> Thanks,
> Rahul