RFR: 8217869: Add count_leading_zeros utility
nils.eliasson at oracle.com
Mon Jan 28 09:36:19 UTC 2019
A very welcome improvement.
Thank you Claes!
On 2019-01-28 10:34, Claes Redestad wrote:
> adding a count_leading_zeros implementation using compiler intrinsics
> means a straightforward optimization of RegMask::find_highest_bit. For
> platforms lacking intrinsic support a more efficient algorithm is
> Adding a 64-bit version would be straightforward, but let's do that
> when we need it.
> Bug: https://bugs.openjdk.java.net/browse/JDK-8217869
> Webrev: http://cr.openjdk.java.net/~redestad/8217869/open.00/
> Testing: tier1-3
> The xlc changes are untested, so it'd be much appreciated if someone
> can run the test on that platform.
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