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?