RFR(M) JDK-8181809 PPC64: Leverage mtfprd/mffprd on POWER8

[Matthew Brandyberry]

Hi Adrian,

These instructions were introduced with POWER8 and are not available in 
earlier ISAs.

On 6/20/17 8:44 AM, John Paul Adrian Glaubitz wrote:
> Hi Matthew!
>
> On Mon, Jun 19, 2017 at 11:27:36AM -0500, Matthew Brandyberry wrote:
>> 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).
> Do these instructions also exist on POWER5 or is this POWER8+ only?
>
> Adrian
>