RFR: 8217629: RegMask::find_lowest_bit can reuse count_trailing_zeros utility

[Tobias Hartmann]

Hi Claes,

looks good to me too.

Best regards,
Tobias

On 23.01.19 13:00, Claes Redestad wrote:
> Hi,
> 
> reusing the count_trailing_zeros utility from RegMask is a simple
> cleanup which may enable optimizations on many platforms, like tzcnt
> on Intel/AMD, and improves inlining.
> 
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8217629
> Webrev: http://cr.openjdk.java.net/~redestad/8217629/open.00/
> 
> On my startup tests and profiles this reduces instructions spent in C2s
> register allocator by ~4%, and ~2% on the total.
> 
> Testing: tier1-3
> 
> Thanks!
> 
> /Claes