hg: jdk9/hs-comp/hotspot: 8087341: C2 doesn't optimize redundant memory operations with G1

[roland.westrelin at oracle.com]

Changeset: 55778b6121e3
Author:    roland
Date:      2016-02-15 10:14 +0100
URL:       http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/55778b6121e3

8087341: C2 doesn't optimize redundant memory operations with G1
Summary: effect of memory barrier in post barrier is too wide
Reviewed-by: kvn, aph
Contributed-by: adinn <adinn at redhat.com>

! src/cpu/aarch64/vm/aarch64.ad
! src/share/vm/opto/graphKit.cpp
! src/share/vm/opto/graphKit.hpp