RFR: 8217629: RegMask::find_lowest_bit can reuse count_trailing_zeros utility
Nils Eliasson
nils.eliasson at oracle.com
Wed Jan 23 15:16:00 UTC 2019
Hi Claes,
Looks great!
Consider it trivial.
/ Nils
On 2019-01-23 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
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