#define mb() asm volatile("mfence":::"memory")
#define rmb() asm volatile("lfence":::"memory")
#define wmb() asm volatile("sfence"::: "memory")
#define mb() asm volatile("mfence":::"memory")
#define rmb() asm volatile("lfence":::"memory")
#define wmb() asm volatile("sfence"::: "memory")