[vector] RFR: Remove VShiftV nodes

[Viswanathan, Sandhya]

Hi Vladimir,

I have only one comment, the following method can be in x86.ad:

1374 bool Matcher::supports_vector_variable_shifts(void) {
1375   return false; // UseAVX >= 2
1376 }

Both 32-bit and 64-bit support vector_variable_shifts when UseAVX >= 2.

Overall, the code looks much cleaner now.  As John said, the code is becoming smaller and smaller :).

Best Regards,
Sandhya

-----Original Message-----
From: panama-dev <panama-dev-bounces at openjdk.java.net> On Behalf Of Vladimir Ivanov
Sent: Thursday, April 09, 2020 1:20 PM
To: panama-dev <panama-dev at openjdk.java.net>
Subject: [vector] RFR: Remove VShiftV nodes

http://cr.openjdk.java.net/~vlivanov/panama/vector/vshift/webrev.00/

Get rid of dedicated nodes for variable shifts and reuse existing [UR|R|L]ShiftV nodes.

Overall, it simplifies the code except detecting when variable shifts are supported. Introduced Matcher::supports_vector_variable_shifts() for that.

The patch is against vectorIntrinsics branch.

Best regards,
Vladimir Ivanov