8 bytes or 4 bytes. The pointer size of 32-bit compiler of 64-bit operating system on 64-bit processor is 8 bytes, and the pointer size of 16-bit compiler of 32-bit operating system on 64-bit processor is 4 bytes, so the length of 64-bit arm pointer is 8 bytes or 4 bytes. British ARM company is the world's leading provider of semiconductor intellectual property rights, and more than 95% of smartphones and tablets in the world adopt ARM architecture.