23. BSWAP Instruction Swap Bytes

• The XCHG instruction is useful for conversion of 16-bit data between little endian and big endian forms.

          xchg    al, ah
  

• For example, the following XCHG converts the data in AX into the other endian form.

• Pentium provides BSWAP instruction to do similar conversion on 32-bit data:

  • BSWAP 32-bit register

• Note: BSWAP works only on data located in a 32-bit register.

• BSWAP swaps bytes of its operand. For example,

          bswap eax
  

• Result of BSWAP EAX