RFR(XS): 8149973: Optimize object alignment check in debug builds.

[Coleen Phillimore]

From
http://cr.openjdk.java.net/~ddmitriev/8149973/webrev.00/src/share/vm/gc/g1/g1OopClosures.inline.hpp.udiff.html
http://cr.openjdk.java.net/~ddmitriev/8149973/webrev.00/src/share/vm/gc/g1/g1RemSet.inline.hpp.udiff.html

Can you just call

    assert(check_obj_alignment(o), "not oop aligned");

rather than repeating the & expression?   The check_obj_alignment is 
inlined.

Coleen

On 2/24/16 5:42 AM, Dmitry Dmitriev wrote:
> Hello,
>
> Please, review small optimization to the object alignment check in the 
> debug builds. In this fix I replace division by MinObjAlignmentInBytes 
> to bitwise AND operation with MinObjAlignmentInBytesMask, because 
> MinObjAlignmentInBytes is a power of two. Suggested construction 
> already used in MacroAssembler, e.g. 
> hotspot/src/cpu/x86/vm/c1_MacroAssembler_x86.cpp).
>
> JBS: https://bugs.openjdk.java.net/browse/JDK-8149973
> webrev.00: http://cr.openjdk.java.net/~ddmitriev/8149973/webrev.00/ 
> <http://cr.openjdk.java.net/%7Eddmitriev/8149973/webrev.00/>
> Testing: jprt, hotspot_all
>
> Thanks,
> Dmitry