w (f) add s4,s2,t2 (c) sw t1,0(s1) (f) lw a2,0(s1) (c) fence r,r (g) fence r,r dma_wmb() fence w,w mb() fence iorw,iorw rmb() fence ri,ri wmb() fence wo,wo smp_load_acquire() l{b|h|w|d}; fence r,rw