RFR (S): JDK-8191328: Avoid unnecessary overhead in CRC32C

Andrew Haley aph at redhat.com
Wed Nov 15 18:44:13 UTC 2017

On 15/11/17 18:38, Vitaly Davidovich wrote:
> On Wed, Nov 15, 2017 at 12:40 PM, Andrew Haley <aph at redhat.com> wrote:
>> On 15/11/17 15:38, Alan Bateman wrote:
>>> Moving the nativeOrder out of the loop make sense but I'm curious about
>>> the context for improving this implementation.
>> I wonder about lifting ByteOrder.nativeOrder().  Maybe it fails to
>> inline because the method is too large: if that happens, we really
>> lose.  I'm not seeing that, though: it seems to be inlined just fine,
>> and has no effect.
>> In any case, this patch doesn't help anything on my test hardware.
> Is this with -Xcomp though? That can generate crap code because
> there's no profiling information.  Not that -Xcomp should be the way
> to test peak performance IMO, but that is the setting that was used I
> believe.

Shrug; maybe.  We shouldn't mess the code up for -Xcomp.

Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671

More information about the core-libs-dev mailing list