Hi Mikael, I tried a release and fastdebug build on aarch64. The release build builds fine and passes a basic smoke test but the fastdebug build fails with the following errors. /home/ed/new_jdk9/hs-comp/hotspot/src/share/vm/jvmci/jvmciCompilerToVM.cpp: In static member function 'static void CompilerToVM::Data::initialize()': /home/ed/new_jdk9/hs-comp/hotspot/src/share/vm/jvmci/jvmciCompilerToVM.cpp:153:37: error: cannot convert 'ByteSize' to 'int' in assignment InstanceKlass_vtable_start_offset = InstanceKlass::vtable_start_offset(); ^ /home/ed/new_jdk9/hs-comp/hotspot/src/share/vm/jvmci/jvmciCompilerToVM.cpp:154:38: error: cannot convert 'ByteSize' to 'int' in assignment InstanceKlass_vtable_length_offset = InstanceKlass::vtable_length_offset() * HeapWordSize; ^ After fixing these the fastdebug build completed and passed the same basic tests. All the best, Ed. On Fri, 2016-01-15 at 18:04 +0100, Mikael Gerdin wrote:
Hi all,
As per the previous discussion in mid-December[0] about moving the _vtable_length field to class Klass, here's the first RFR and webrev, according to my suggested plan[1]:
My current plan is to first modify the vtable_length_offset accessor to return a byte offset (which is what it's translated to by all callers).
Then I'll tackle moving the _vtable_len field to Klass.
Finally I'll try to consolidate the vtable related methods to Klass, where they belong.
This change actually consists of three changes: * modifying InstanceKlass::vtable_length_offset to become a byte offset and use the ByteSize type to communicate the scaling. * modifying InstanceKlass::vtable_start_offset to become a byte offset and use the ByteSize type, for symmetry reasons mainly. * adding a vtableEntry::size_in_bytes() since in many places the vtable entry size is used in combination with the vtable start to compute a byte offset for vtable lookups.
I don't foresee any issues with the fact that the byte offset is represented as an int, for two reasons: 1) If the offset of any of these grows to over 2 gigabytes then we have a huge footprint problem with InstanceKlass 2) The offsets are converted to byte offsets and stored in ints already in the cpu specific code I've modified.
Bug link: https://bugs.openjdk.java.net/browse/JDK-8147461 Webrev: http://cr.openjdk.java.net/~mgerdin/8147461/webrev.0/
Testing: JPRT on Oracle supported platforms, testing on AARCH64 and PPC64 would be much appreciated, appropriate mailing lists have been CC:ed to notify them of the request.
[0] http://mail.openjdk.java.net/pipermail/hotspot-dev/2015-December/021152.html [1] http://mail.openjdk.java.net/pipermail/hotspot-dev/2015-December/021224.html
Thanks! /Mikael