Thanks, John!
Will fix the typo before pushing the fix.
Best regards,
Vladimir Ivanov
On 3/16/15 9:51 PM, John Rose wrote:
Good fix, thanks. — John
P.S. I noticed a typo: "it's" (contraction of "it is") should be "its" (genitive of
"it").
On Mar 16, 2015, at 11:26 AM, Vladimir Ivanov <vladimir.x.iva...@oracle.com>
wrote:
http://cr.openjdk.java.net/~vlivanov/8074548/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8074548
MethodHandleImpl::profileBoolean doesn't update never-taken branch count when
hitting a deopt on it. As a result, for rarely taken branches consequent
compilations consider them as never-taken and prune them again causing repeated
deopts. It severely affects peak performance.
The fix is to update MHI::profileBoolean intrinsic to insert a guard and
uncommon trap w/ reexecute bit set for never-seen value. Once previously never
seen value is encountered, the execution resumes after deopt in
MHI::profileBoolean and corresponding count becomes non-zero.
The guard doesn't add any additional overhead, since it dominates all value
usages and all branches on the same value are eliminated.
Testing: java/lang/invoke, nashorn, octane
_______________________________________________
mlvm-dev mailing list
mlvm-dev@openjdk.java.net
http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
