The c2 compiler inserts MemBarAcquire/Release nodes to enforce memory ordering in various places. Some order a certain load/store with other operations. inline_unsafe_fence() inserts MemBars that do not correspont to a memory operation. So far, the same nodes were used. This change introduces MemBarFenceAcquire/Release to use where no dedicated load/store is ordered. With this change, these nodes can be matched differently, what is needed on PPC64. ---------------------------- This is preparation for PPC64 integration: http://openjdk.java.net/jeps/175 This and following ppc64 changes will go into staging repository first and tested there: http://hg.openjdk.java.net/ppc-aix-port/stage/ Extend Load and Store nodes to know about memory ordering. http://hg.openjdk.java.net/ppc-aix-port/jdk8/hotspot/file/df79d76c17ab/ppc_patches/0113_opto-Extend_Load_and_Store_nodes_to_know_about_memory_ordering.patch
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