Intel Pentium CPU Instruction Set Reference
BSWAP instruction - Byte Swap
| Code |
Mnemonic |
Description |
| 0F C8+ rd |
BSWAP r32 |
Reverses the byte order of a 32-bit register. |
Description
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.
| Operands |
Bytes |
Clocks |
| r32 |
2 |
1 |
NP |
Flags
| ID |
unaffected |
DF |
unaffected |
| VIP |
unaffected |
IF |
unaffected |
| VIF |
unaffected |
TF |
unaffected |
| AC |
unaffected |
SF |
unaffected |
| VM |
unaffected |
ZF |
unaffected |
| RF |
unaffected |
AF |
unaffected |
| NT |
unaffected |
PF |
unaffected |
| IOPL |
unaffected |
CF |
unaffected |
| OF |
unaffected |
