[14] RFR (L): 8235405: C2: Merge AD instructions for different vector operations

[Vladimir Ivanov]

Hi Sandhya,

We need 1 more (R)eview before I can push it.

PS: and 8234392 [1] which it depends on.

Best regards,
Vladimir Ivanov

[1] 
https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-December/036291.html

On 09.12.2019 21:54, Viswanathan, Sandhya wrote:
> Hi Vladimir,
> 
> It will be wonderful if we can get this checked in by Thursday deadline for JDK 14.
> 
> Best Regards,
> Sandhya
> 
> 
> -----Original Message-----
> From: Vladimir Ivanov <vladimir.x.ivanov at oracle.com>
> Sent: Thursday, December 05, 2019 4:01 AM
> To: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>
> Cc: Bhateja, Jatin <jatin.bhateja at intel.com>; Viswanathan, Sandhya <sandhya.viswanathan at intel.com>
> Subject: [14] RFR (L): 8235405: C2: Merge AD instructions for different vector operations
> 
> http://cr.openjdk.java.net/~vlivanov/jbhateja/8235405/webrev.00/all
> https://bugs.openjdk.java.net/browse/JDK-8235405
> 
> Reduce the number of AD instructions needed to implement vector operations by merging existing ones. The patch covers the following
> operations:
>     - LoadVector
>     - StoreVector
>     - RoundDoubleModeV
>     - AndV
>     - OrV
>     - XorV
>     - MulAddVS2VI
>     - PopCountVI
> 
> Indiviual patches:
>   
> http://cr.openjdk.java.net/~vlivanov/jbhateja/8235405/webrev.00/individual
> 
> As Jatin described, merging is applied only to AD instructions of similar shape. There are some more opportunities for reduction/merging left, but they are deliberately left out for future work.
> 
> The patch is derived from the inintial version of generic vector support [1]. Generic vector support was reviewed earlier and the other parts of refactorings in x86.ad  will be posted for review separately (7 more patches pending).
> 
> Testing: tier1-4, test run on different CPU flavors (KNL, SKL, etc)
> 
> Contributed-by: Jatin Bhateja <jatin.bhateja at intel.com>
> Reviewed-by: vlivanov, sviswanathan, ?
> 
> Best regards,
> Vladimir Ivanov
> 
> [1]
> https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-August/034822.html
>