RFR: 8278868: Add x86 vectorization support for Long.bitCount()

Mon Dec 20 19:49:10 UTC 2021

On Wed, 15 Dec 2021 23:51:19 GMT, Vamsi Parasa <duke at openjdk.java.net> wrote:

> Vectorization support of Integer.bitCount() already exists but currently the same support is lacking for Long.bitCount(). Similar to the C2 PopCountVI node, we created a C2 PopCountVL node and used vpopcntq x86 instruction to enable vectorized Long.bitCount(). This patch shows 2.57x improvement in performance on a JMH micro benchmark due to x86 vectorization.

This patch shows 2.57x improvement in performance on a JMH micro benchmark due to x86 vectorization.

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PR: https://git.openjdk.java.net/jdk/pull/6857