aarch64 Memory Model: LDAR/STLR Visibility Limits Under Concurrent Access
Synchronization Constraints in Weakly Ordered Memory The ARMv8-A architecture utilizes a weakly ordered memory model where hardware may reorder memory accesses to maximize throughput. To manage synchronization, the architecture provides Load-Acquire (LDAR) and Store-Release (STLR) instructions, which establish one-way barriers to ensure specific ordering bet