Thanks for cc:ing us.
This is not the correct way to check for compiler versions. Nor is it
the correct place.
I don't have time for a full reply tonight, but will return with a
better reply tomorrow.
/Magnus
On 2020-06-03 19:47, Daniel D. Daugherty wrote:
Adding build-dev@... since this is a build system change.
As for the right HotSpot team, I'm not sure who should be making
the call on changing the way unsafe.cpp is built for macOSX. My guess
when I moved the bug to hotspot/runtime was that someone on the Runtime
team would know, but...
Dan
On 6/3/20 1:38 PM, Vladimir Kempik wrote:
Hello
Can somebody please review this simple change ?
Thanks
6 мая 2020 г., в 12:43, Vladimir Kempik <vkem...@azul.com> написал(а):
Adding hotspot-runtime-dev
23 апр. 2020 г., в 18:26, Vladimir Kempik <vkem...@azul.com>
написал(а):
Hello
Please review a fix for JDK-8243470
Long time ago as part of JEP284: New HotSpot Build System this fix
was applied to jdk9 https://bugs.openjdk.java.net/browse/JDK-8152666
At that time it was decided to lower optimisation level for
unsafe.cpp from O2 to O1 only for clang on Macosx.
I suppose it was done due to issues in Set/Get<Object> helper
functions where too optimistic optimisations were eliminating some
null pointer checks. it was probably a clang bug.
That issue could be checked with test
jdk/test/sun/misc/CopyMemory.java.
I believe that workaround (going from O2 to O1) produced this issue
- https://bugs.openjdk.java.net/browse/JDK-8234963
(Thread.getStackTrace is slow with clang).
JDK-8234963 can only be seen on mac with libjvm compiled by clang.
Here I propose the patch which eliminates that workaround for clang
8+.
I have tested clang versions 8/9/9.1/10, all of them showed good
results:
1) CopyMemory test passes fine on 11/14/15.
2) jdk11/jdk14 passed tck. Regression testing were good as well.
jdk15: no new failures in tck.
3) The testRandom "benchmark" from 8234963 shows great improvements
on my machine, going down from ~200 seconds to ~150 seconds (the
newer clang the better result). For comparision, gcc built libjvm
for jdk11 shows ~130 seconds on my machine.
The webrev: http://cr.openjdk.java.net/~vkempik/8243470/webrev.00/
getStackTrace benchmark:
http://cr.openjdk.java.net/~vkempik/8243470/TestRandom.java
The bug: https://bugs.openjdk.java.net/browse/JDK-8243470
Thanks, Vladimir
