| Primitive | Description |
| lwarx | CPU-provided operation to atomically read a memory location and set a reservation flag. |
| stwcx | CPU-provided operation to atomically write to a memory location. If the reservation flag is set, and in any case return the value of the reservation flag. |
| aAdd | Atomically mem[addr] += delta; return mem[addr]. |
| aSwap | Atomically tmp = mem[addr1]; mem[addr1] = mem[addr2]; mem[addr2] = tmp. |
| aIandF | Atomically tmp = mem[addr1]; mem[tmp] += delta;return tmp. |