[8u] RFR (M) 8181809 PPC64: Leverage mtfprd/mffprd on POWER8
mbrandy at linux.vnet.ibm.com
Thu Oct 12 16:17:12 UTC 2017
On 9/28/17 12:53 PM, Matthew Brandyberry wrote:
> Please review this backport of 8181809 for jdk8u.
> It applies cleanly to jdk8u except for the lack of C1 support on PPC
> in 8u -- thus those changes are omitted here.
> This is a PPC-specific hotspot optimization that leverages the
> mtfprd/mffprd instructions for for movement between general purpose
> and floating point registers (rather than through memory). It yields a
> ~35% improvement measured via a microbenchmark.
> webrev :http://cr.openjdk.java.net/~mbrandy/8181809/jdk8u/v1
> bug :https://bugs.openjdk.java.net/browse/JDK-8181809
> Thank you.
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