INS
show disass and source set disassemble-next-line on
enter func si/s
show register value i r $rbx x $rbx
examine memory
以16进制格式打印数组前a16个byte的值：
(gdb) x/16xb a
0x7fffffffe4a0: 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07
0x7fffffffe4a8: 0x08 0x09 0x0a 0x0b 0x0c 0x0d 0x0e 0x0f