tomasz@tomasz-lenovo-ideapad-Y530:~$ lscpu
Architecture:          i686
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                2
On-line CPU(s) list:   0,1
Thread(s) per core:    1
Core(s) per socket:    2
Socket(s):             1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 23
Stepping:              6
CPU MHz:               2000.000
BogoMIPS:              4000.12
Cache L1d:             32K
Cache L1i:             32K
Cache L2:              3072K

I can see that my architecture is 32-bit (i686). But CPU op-mode(s) are 32-bit and 64-bit. The question is: how come? How is it handled that a 32-bit processor performs 64-bit operations? I guess it's a lot slower than native 32-bit operations. Is it built-in processor functionality (to emulate being 64-bit) or is it software dependent? When does it make sense for a 32-bit processor to run 64-bit operations?