RFR: JDK-8205055: Fix compilation optimization errors with new Solaris toolchain

[Erik Joelsson]

Hello,

On 2018-06-15 05:44, Magnus Ihse Bursie wrote:
> On 2018-06-15 01:26, gary.adams at oracle.com wrote:
>> Locally tested the fix below and via mach5 jobs.
>> The ~50 failed tests all completed successfully.
>> It'd be good for Erik to repeat his full testing with
>> this patch included in case it blocked other issues
>> from being observed.
>>
>> This fix can be integrated after the sync from jdk/client.
>>
>>  Issue: https://bugs.openjdk.java.net/browse/JDK-8205055
>>
>> Proposed fix:
>>
>> diff --git a/make/hotspot/lib/JvmOverrideFiles.gmk 
>> b/make/hotspot/lib/JvmOverrideFiles.gmk
>> --- a/make/hotspot/lib/JvmOverrideFiles.gmk
>> +++ b/make/hotspot/lib/JvmOverrideFiles.gmk
>> @@ -74,6 +74,8 @@
>>
>>  else ifeq ($(OPENJDK_TARGET_OS), solaris)
>>    ifneq ($(DEBUG_LEVEL), slowdebug)
>> + # dev studio 12.6 workaround
>> + BUILD_LIBJVM_arguments.cpp_OPTIMIZATION := LOW
>
> The if should test
> ifeq ($(TOOLCHAIN_TYPE), solstudio)
> since this is a compiler issue, not an OS issue.
>
> Ideally, it should also test if using version 12.6, but unfortunately 
> there's currently no elegant way of expressing that in the makefiles, 
> so I'm OK with the workaround of just having a comment. I assume, from 
> the name and a quick glance at the file, that the contents makes it 
> unlikely that a lowevered optimization level wouldprovoke a 
> performance regression in pre-12.6 solstudio compilations.
>
> Still, it would be nice if you are able to drill down the issue to 
> figure out exactly why a higher optimization level causes this file to 
> be incorrectly compiled. It might be code in hotspot with undefined 
> behavior, or it might be bugs in solstudio. In any case, it should be 
> addressed. As an initial fix to allow compilation to proceed, this is 
> fine, though.
>
I have run more testing using this patch and it does look like it works 
pretty well with just this change. Nothing sticks out.

I agree with Magnus that it needs a TOOLCHAIN_TYPE check.

Will you file a followup for investigating what actually goes wrong?

/Erik