Reverses the byte order of a 32-bit (destination) register: bits 0 through 7 are swapped with bits 24 through 31, and bits 8 through 15 are swapped with bits 16 through 23. This instruction is provided for converting little-endian values to big-endian format and vice versa.
To swap bytes in a word value (16-bit register), use the XCHG instruction. When the BSWAP instruction references a 16-bit register, the result is undefined.
The BSWAP instruction is not supported on IA-32 processors earlier than the Intel486 processor family. For compatibility with this instruction, include functionally equivalent code for execution on Intel processors earlier than the Intel486 processor family.