Looks like only 32-bit is affected. Both Server (C2) and Client (C1) VMs.
64-bit VM pass all combinations: Tiered, C2 only (-TieredCompilation),
C1 only (-XX:+TieredCompilation -XX:TieredStopAtLevel=1) with and
without intrinsics.
32-bit Client VM (C1) fails with both, -XX:-UseUnalignedAccesses and
-XX:+UseUnalignedAccesses.
$ bin/java -client -XX:+UnlockDiagnosticVMOptions
-XX:-UseUnalignedAccesses HeapByteBufferTest
Exception in thread "main" java.lang.RuntimeException
at MyByteBuffer.ck(HeapByteBufferTest.java:201)
at MyByteBuffer.getLong(HeapByteBufferTest.java:211)
at HeapByteBufferTest.step(HeapByteBufferTest.java:311)
at HeapByteBufferTest.run(HeapByteBufferTest.java:347)
at HeapByteBufferTest.main(HeapByteBufferTest.java:362)
$ bin/java -client -XX:+UnlockDiagnosticVMOptions
-XX:+UseUnalignedAccesses HeapByteBufferTest
Exception in thread "main" java.lang.RuntimeException
at MyByteBuffer.ck(HeapByteBufferTest.java:201)
at MyByteBuffer.getLong(HeapByteBufferTest.java:211)
at HeapByteBufferTest.step(HeapByteBufferTest.java:311)
at HeapByteBufferTest.run(HeapByteBufferTest.java:347)
at HeapByteBufferTest.main(HeapByteBufferTest.java:362)
32-bit Server VM without tiered (-TieredCompilation) FAILS too in both
cases! Note, without intrinsics it failed in different place.
$ bin/java -server -XX:-TieredCompilation -XX:+UnlockDiagnosticVMOptions
-XX:-UseUnalignedAccesses HeapByteBufferTest
Exception in thread "main" java.lang.RuntimeException
at MyByteBuffer.ck(HeapByteBufferTest.java:207)
at MyByteBuffer.getDouble(HeapByteBufferTest.java:215)
at HeapByteBufferTest.step(HeapByteBufferTest.java:329)
at HeapByteBufferTest.run(HeapByteBufferTest.java:347)
at HeapByteBufferTest.main(HeapByteBufferTest.java:362)
$ bin/java -server -XX:-TieredCompilation -XX:+UnlockDiagnosticVMOptions
-XX:+UseUnalignedAccesses HeapByteBufferTest
Exception in thread "main" java.lang.RuntimeException
at MyByteBuffer.ck(HeapByteBufferTest.java:201)
at MyByteBuffer.getLong(HeapByteBufferTest.java:211)
at HeapByteBufferTest.step(HeapByteBufferTest.java:311)
at HeapByteBufferTest.run(HeapByteBufferTest.java:347)
at HeapByteBufferTest.main(HeapByteBufferTest.java:362)
For some reasons Server VM only pass when TieredCompilation is enabled.
Looking on -XX:+PrintCompilation -XX:+PrintInlining output I see that
UseUnalignedAccesses affects intrinsics as designed.
Thanks,
Vladimir
On 3/25/15 2:13 AM, Andrew Haley wrote:
On 24/03/15 23:40, Vladimir Kozlov wrote:
The test failed when run it in JPRT with 32-bit fastdebug *Client* VM (-client)
on linux-x86:
java.lang.RuntimeException
at MyByteBuffer.ck(HeapByteBufferTest.java:201)
at MyByteBuffer.getLong(HeapByteBufferTest.java:211)
at HeapByteBufferTest.step(HeapByteBufferTest.java:311)
at HeapByteBufferTest.run(HeapByteBufferTest.java:347)
at HeapByteBufferTest.main(HeapByteBufferTest.java:362)
Could be intrinsic in C1 does not work correctly? Please, look.
I certainly will. That is odd: there's no reason I can think of why
this might happen, and I know that the test running on a server build
runs C1 code for a while so it has been tested. I guess it must be a
rare edge case. Still, I'm quite pleased that the test I wrote
detected the failure.
Do you know if this was running with +UseUnalignedAccesses?
I'm not going to be able to analyse this for a few days. Expect a
report (and hopefully a fix) next week.
Thanks,
Andrew.
