RFR : JDK-8067744 : XMM/SSE float register values corrupted by JNI_CreateVM call in JRE 8 (Windows)

[Berg, Michael C]

Dmitry:

The bottom two restore contexts can use the immediately prior values and set function:

VM_Version::set_evex_cpuFeatures(); // 466..468 and 497..499
UseAVX =
UseSSE =
// can be removed.

Wrt the values set right before, they have not changed, so you will not need the additional code to change state its already done.

362..382 can be cleaned up to only require one set of avx/sse and cpuFeatures.

Regards,
Michael

-----Original Message-----
From: hotspot-compiler-dev [mailto:hotspot-compiler-dev-bounces at openjdk.java.net] On Behalf Of Vladimir Kozlov
Sent: Thursday, October 27, 2016 7:19 AM
To: Dmitry Chuyko <dmitry.chuyko at oracle.com>; hotspot-compiler-dev at openjdk.java.net
Subject: Re: RFR : JDK-8067744 : XMM/SSE float register values corrupted by JNI_CreateVM call in JRE 8 (Windows)

Looks good.

thanks,
Vladimir

On 10/27/16 4:11 AM, Dmitry Chuyko wrote:
> Now generate_get_cpu_info() preserves full xmm7,8,31 in AVX512 case and lower xmm7,8,15 in non-512 case (touched ones).
>
> Webrev: 
> http://cr.openjdk.java.net/~vlivanov/dchuyko/8067744/webrev.01/
>
> General testing done, and new test passes with the patch on the machine where the bug is reproducible.
>
> Also thanks to Vladimir Ivanov for initial test draft and help with webrev.
>
> -Dmitry
>
> On 10/20/2016 08:25 PM, Vladimir Kozlov wrote:
>> Hi Dmitry,
>>
>> New code does not restore whole 64-bit of xmm7,8,15 in AVX512 case. I 
>> think you can totally separate save/restore for these cases.
>>
>> thanks,
>> Vladimir
>>
>> On 10/19/16 4:49 AM, Dmitry Chuyko wrote:
>>> Summary: Few xmm registers saved on stack and restored in 
>>> generate_get_cpu_info on Windows, a bit different on 2 detection paths.
>>> New test calls native executable that loads jvm shared library and 
>>> checks if some double values are corrupted. The test reproduced the 
>>> problem on my machine with current devkit but not on Aurora.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8067744
>>>
>>> Webrev: 
>>> http://javaweb.us.oracle.com/~dchuyko/webrevs/8067744/webrev.00/
>>>
>>> ...............
>>>
>