RFR(XS):8216580:X86: Fix generation of VNNI vector code by allowing adjacent LoadS nodes to be isomorphic

[Vladimir Kozlov]

Hi Vivek,

Most of new checks are loop invariant: !s1_ctrl_inv and 
!s1_ctrl->is_RangeCheck()

I think you don't need to search for is_muladds2i() if those checks 
return false.

Most general question is: why it should apply only to muladds2i nodes 
only? Can we do the same for others?

Thanks,
Vladimir

On 2/8/19 2:17 PM, Deshpande, Vivek R wrote:
> Hi Vladimir
> 
> Would you please take a look at this patch.
> 
> The Adjacent LoadS have different control RangeCheck node for accesses of type a[2i] and a[2i+1].
> This patch allows those nodes to be isomorphic as they belong same counted loop and MulAddS2I nodes.
>   
> Webrev:
> http://cr.openjdk.java.net/~vdeshpande/8216580/webrev.01/
> Bug ID:
> https://bugs.openjdk.java.net/browse/JDK-8216580
> 
> Regards,
> Vivek
> 
> -----Original Message-----
> From: Deshpande, Vivek R
> Sent: Monday, January 28, 2019 9:45 AM
> To: Tobias Hartmann <tobias.hartmann at oracle.com>; hotspot-compiler-dev at openjdk.java.net compiler <hotspot-compiler-dev at openjdk.java.net>; Vladimir Kozlov <vladimir.kozlov at oracle.com>
> Cc: Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Raj, Guru <guru.raj at intel.com>
> Subject: RE: RFR(XS):8216580:X86: Fix generation of VNNI vector code by allowing adjacent LoadS nodes to be isomorphic
> 
> Hi Vladimir
> 
> Would you please take a look at the patch.
> The Adjacent LoadS have different control RangeCheck node for accesses of type a[2i] and a[2i+1].
> This patch allows those nodes to be isomorphic as they belong same counted loop and MulAddS2I nodes.
>   
> Webrev:
> http://cr.openjdk.java.net/~vdeshpande/8216580/webrev.01/
> 
> Regards,
> Vivek
> 
> -----Original Message-----
> From: Tobias Hartmann [mailto:tobias.hartmann at oracle.com]
> Sent: Tuesday, January 15, 2019 2:57 AM
> To: Deshpande, Vivek R <vivek.r.deshpande at intel.com>; hotspot-compiler-dev at openjdk.java.net compiler <hotspot-compiler-dev at openjdk.java.net>
> Cc: Vladimir Kozlov <vladimir.kozlov at oracle.com>; Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Raj, Guru <guru.raj at intel.com>
> Subject: Re: RFR(XS):8216580:X86: Fix generation of VNNI vector code by allowing adjacent LoadS nodes to be isomorphic
> 
> Hi Vivek,
> 
> please add parentheses around the == comparison in lines 1225,1226.
> 
> Otherwise this looks reasonable to me but I'm not too familiar with that code.
> 
> Best regards,
> Tobias
> 
> On 12.01.19 01:03, Deshpande, Vivek R wrote:
>> Hi Tobias
>>
>> The webrev for the bug JDK-821650 is here:
>> http://cr.openjdk.java.net/~vdeshpande/8216580/webrev.00/
>> This fixes generation of vector code by allowing adjacent LoadS nodes to be isomorphic when they have different control RangeCheck nodes for a[i] and a[i+1] accesses in same MulAddS2I node.
>> Could you please review it.
>>
>> Regards,
>> Vivek
>>
>> -----Original Message-----
>> From: Deshpande, Vivek R
>> Sent: Friday, January 11, 2019 11:38 AM
>> To: 'Tobias Hartmann' <tobias.hartmann at oracle.com>;
>> hotspot-compiler-dev at openjdk.java.net compiler
>> <hotspot-compiler-dev at openjdk.java.net>
>> Cc: Vladimir Kozlov <vladimir.kozlov at oracle.com>; Viswanathan, Sandhya
>> <sandhya.viswanathan at intel.com>; Raj, Guru <guru.raj at intel.com>
>> Subject: RE: RFR(S):8216050:X86: Fix for Superword optimization fails
>> with assert(0 <= i && i < _len) failed: illegal index
>>
>> Hi Tobias
>>
>> Thanks for reviewing the patch.
>> I have made the changes according to your suggestion.
>> In this webrev:
>> http://cr.openjdk.java.net/~vdeshpande/8216050/webrev.01/
>> I have fix for the crash reported in the 8216050.
>>
>> The lower cost is needed for generation of vpdpwssd instruction, by combining AddVI and MulAddVS2VI.
>> For other instructions pmaddwd and vpmaddwd, they get generated on platforms upto skylake with default cost.
>>
>> I have updated the bug also with the link to webrev.
>>
>> I have created a different bug JDK-8216580 for
>>   3) Fix generation of vector code by allowing adjacent LoadS nodes to be isomorphic when they have different control RangeCheck nodes
>>       for a[i] and a[i+1] accesses in same MulAddS2I node
>>
>> Thank you.
>> Regards,
>> Vivek
>>
>> -----Original Message-----
>> From: Tobias Hartmann [mailto:tobias.hartmann at oracle.com]
>> Sent: Friday, January 11, 2019 4:49 AM
>> To: Deshpande, Vivek R <vivek.r.deshpande at intel.com>;
>> hotspot-compiler-dev at openjdk.java.net compiler
>> <hotspot-compiler-dev at openjdk.java.net>
>> Cc: Vladimir Kozlov <vladimir.kozlov at oracle.com>; Viswanathan, Sandhya
>> <sandhya.viswanathan at intel.com>; Raj, Guru <guru.raj at intel.com>
>> Subject: Re: RFR(S):8216050:X86: Fix for Superword optimization fails
>> with assert(0 <= i && i < _len) failed: illegal index
>>
>> Hi Vivek,
>>
>> On 11.01.19 07:58, Deshpande, Vivek R wrote:
>>> 1) Fix for the crash by matching the operand by swapping to right positions.
>>
>> Looks good but the change to loopopts.cpp:530 screwed up the indentation around the ifs, please fix.
>>
>>> 2) Cost based generation of vpdpwssd instruction.
>>
>> Other instructions added by JDK-8214751 still miss a cost definition, for example:
>> http://hg.openjdk.java.net/jdk/jdk/rev/4bb6e0871bf7#l5.20
>>
>>> 3) Fix generation of vector code by allowing adjacent LoadS nodes to
>>> be isomorphic when they have different control RangeCheck nodes
>>>      for a[i] and a[i+1] accesses in same MulAddS2I node
>>
>> This is unrelated to the original bug, right? If so, this should be integrated with a separate RFE.
>>
>> Thanks,
>> Tobias
>>