RFR(M) 8078122 : YMM registers upper 128 bits may get clobbered by a JNI call on windows

[Kharbas, Kishor]

Thanks Vladimir!

-----Original Message-----
From: Vladimir Kozlov [mailto:vladimir.kozlov at oracle.com] 
Sent: Tuesday, September 6, 2016 10:12 AM
To: Kharbas, Kishor <kishor.kharbas at intel.com>; hotspot-compiler-dev at openjdk.java.net
Subject: Re: RFR(M) 8078122 : YMM registers upper 128 bits may get clobbered by a JNI call on windows

Good. I start testing these changes. I will push it if testing pass.

Thanks,
Vladimir

On 9/2/16 3:07 PM, Kharbas, Kishor wrote:
> Thanks Vladimir,
>
> I have updated the patch : 
> http://cr.openjdk.java.net/~vdeshpande/8078122/webrev.02/
>
> I looked for other places in src/cpu/x86/vm. I feel every case is covered.
>
> - Kishor
>
> -----Original Message-----
> From: Vladimir Kozlov [mailto:vladimir.kozlov at oracle.com]
> Sent: Thursday, September 1, 2016 11:39 AM
> To: Kharbas, Kishor <kishor.kharbas at intel.com>; 
> hotspot-compiler-dev at openjdk.java.net
> Subject: Re: RFR(M) 8078122 : YMM registers upper 128 bits may get 
> clobbered by a JNI call on windows
>
> Good. But looks like some code relied on old stack layout in stubs, for example sha256_AVX2():
>
> #ifndef _WIN64
>    _XMM_SAVE_SIZE = 0,
> #else
>    _XMM_SAVE_SIZE = 8*16,
> #endif
>
> Please, check that all other related code is fixed too. (I looked on all cases of _WIN64 in src/cpu/x86/vm/).
>
> Thanks,
> Vladimir
>
> On 8/31/16 10:17 PM, Kharbas, Kishor wrote:
>> Hello,
>>
>> I removed the unwanted save and restore of registers in the range XMM6-XMM31 from the x64_64 stubs.
>> I also removed the #ifdef _WIN64 block from x86.ad file.
>>
>> Link to the new patch :
>> http://cr.openjdk.java.net/~vdeshpande/8078122/webrev.01/
>>
>> Thanks
>> Kishor
>>
>>
>> -----Original Message-----
>> From: Kharbas, Kishor
>> Sent: Wednesday, August 24, 2016 6:24 PM
>> To: Vladimir Kozlov <vladimir.kozlov at oracle.com>; 
>> hotspot-compiler-dev at openjdk.java.net
>> Cc: Kharbas, Kishor <kishor.kharbas at intel.com>
>> Subject: RE: RFR(M) 8078122 : YMM registers upper 128 bits may get 
>> clobbered by a JNI call on windows
>>
>> Thanks Vladimir for quick feedback.
>> I will look into the stubs which save the registers in the range XMM6-XMM31. Also the first comment makes perfect sense.
>>
>> Thanks
>> Kishor
>>
>> -----Original Message-----
>> From: Vladimir Kozlov [mailto:vladimir.kozlov at oracle.com]
>> Sent: Wednesday, August 24, 2016 3:08 PM
>> To: Kharbas, Kishor <kishor.kharbas at intel.com>; 
>> hotspot-compiler-dev at openjdk.java.net
>> Subject: Re: RFR(M) 8078122 : YMM registers upper 128 bits may get 
>> clobbered by a JNI call on windows
>>
>> Hi Kishor,
>>
>> First, #ifdef _WIN64 is not needed anymore since calling convention is similat to unix now.
>>
>> Second, I would like you to look more broadly. With this change we don't need to preserve XMM6-XMM31 in our stubs for WIN64. I am not sure that we can remove all #ifdef _WIN64 there but for most of them I think we can do. Please, look.
>>
>> Thanks,
>> Vladimir
>>
>> On 8/24/16 2:40 PM, Kharbas, Kishor wrote:
>>> Requesting the community to review the patch for
>>> https://bugs.openjdk.java.net/browse/JDK-8078122
>>>
>>> Webrev : http://cr.openjdk.java.net/~vdeshpande/8078122/webrev.00
>>>
>>> The patch changes the definitions of registers XMM6-XMM31 for WIN64.
>>>
>>> Thank you.
>>>
>>> Kishor
>>>