RFR: 8073093: AARCH64: C2 generates poor code for ByteBuffer accesses

Andrew Haley aph at redhat.com
Fri Feb 13 16:07:13 UTC 2015


On 02/13/2015 04:05 PM, Alan Bateman wrote:
> On 13/02/2015 13:38, Andrew Haley wrote:
>> java.​nio.​DirectByteBuffer.getXXX is slow for types larger than byte
>> because the runtime does not know that AArch64 can perform unaligned
>> memory accesses.
>>
>> The problem is due to this code in java.nio.Bits.unaligned():
>>
>>          unaligned = arch.equals("i386") || arch.equals("x86")
>>              || arch.equals("amd64") || arch.equals("x86_64");
>>
>> If we add AArch64 to this list code quality is very much improved.
>>
>> http://cr.openjdk.java.net/~aph/8073093/
>>
> Make sense, I assume this will go in when JEP 237 is pushed.

It will, but I need approval to push to the JEP 237 staging repo.
'Cos them's the rules.  :-)

Andrew.




More information about the core-libs-dev mailing list