SHLD shifts “dest” to the left “count” times and the bit positions opened are filled with the most significant bits of “src”.
SHRD shifts “dest” to the right “count” times and the bit positions opened are filled with the least significant bits of the second operand.
Only the 5 lower bits of “count” are used.
Usage:
SHLD dest,src,count SHRD dest,src,count
Modifies flags:
CF PF SF ZF (OF,AF undefined)
| Clocks | Size | |||||
|---|---|---|---|---|---|---|
| Operands | 808x | 286 | 386 | 486 | Bytes | |
| reg16,reg16,immed8 | - | - | 3 | 2 | 4 | |
| reg32,reg32,immed8 | - | - | 3 | 2 | 4 | |
| mem16,reg16,immed8 | - | - | 7 | 3 | 6 | |
| mem32,reg32,immed8 | - | - | 7 | 3 | 6 | |
| reg16,reg16,CL | - | - | 3 | 3 | 3 | |
| reg32,reg32,CL | - | - | 3 | 3 | 3 | |
| mem16,reg16,CL | - | - | 7 | 4 | 5 | |
| mem32,reg32,CL | - | - | 7 | 4 | 5 | |