RFR(M):8214751: X86: Support for VNNI instruction
vladimir.kozlov at oracle.com
Wed Dec 12 16:39:53 UTC 2018
This looks good to me. Let me test it.
On 12/10/18 3:46 PM, Deshpande, Vivek R wrote:
> Hi Vladimir
> I have the patch which adds the check that all the nodes belong to same loop.
> Also I have added a jtreg test.
> Could you please take a look at the patch.
> -----Original Message-----
> From: Vladimir Kozlov [mailto:vladimir.kozlov at oracle.com]
> Sent: Friday, December 7, 2018 11:22 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: Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Raj, Guru <guru.raj at intel.com>
> Subject: Re: RFR(M):8214751: X86: Support for VNNI instruction
> On 12/7/18 10:33 AM, Deshpande, Vivek R wrote:
>> Hi Vladimir
>> This patch is useful for AI ML/DL applications such convolution based Neural Nets.
> Add to RFE's Description this comment. May be have some JMH benchmark results to show improvement.
>> I have updated the patch with your suggestion.
>> I am creating the MulAddS2I patch late and before vectoriztion.
> Add check that all combined nodes belongs to the same loop - you have this information since you inside loopopts.
>> The updated webrev is here:
>> I am also working on the test.
>> -----Original Message-----
>> From: Vladimir Kozlov [mailto:vladimir.kozlov at oracle.com]
>> Sent: Thursday, December 6, 2018 11:59 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>
>> Subject: Re: RFR(M):8214751: X86: Support for VNNI instruction
>> Hi Vivek,
>> What applications benefit this optimizations?
>> This optimization may prevent some constant folding and others IGVN optimizations and RA since MulAddS2INode is generated too early I think. The only benefit we will have only if vectors are generated. Can you generate vectors without MulAddS2INode? Or create MulAddS2INode just before vectorization and expand it if vectorization failed? I would prefer first solution to have a struct in SuperWord code which find such pattern and try to vectorize it.
>> You need to add test to verify correctness of results.
>> Add UseAVX == 0 check to predicates which use SSE2 code. Otherwise they may be selected even if UseAVX > 0.
>> On 12/3/18 8:58 PM, Deshpande, Vivek R wrote:
>>> Hi All
>>> Could you please review the VNNI VPDPWSSD instruction support with autovectorization.
>>> It can vectorize this operation in the loop:
>>> out[i] += ((in1[2*i] * in2[2*i]) + (in1[2*i+1] * in2[2*i+1])); More
>>> information on VNNI can be found here:
>>> t ure-instruction-set-extensions-programming-reference.pdf
>>> The initial performance gains with micro on skylake with AVX3 is 10.8x.
>>> and it generates
>>> vmovdqu xmm3, xmmword ptr [rbp+r8*2+0x10] vmovdqu xmm6, xmmword ptr
>>> [rdx+r8*2+0x10] vpmaddwd xmm3, xmm6, xmm3 vpaddd xmm3, xmm3, xmmword
>>> ptr [r9+rdi*4+0x10] vmovdqu xmmword ptr [r9+rdi*4+0x10], xmm3
>>> It can generate vpdpwssd instruction on cascadelake.
>>> The webrev is here:
>>> The jbs entry for the same is here:
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