# PSRLDQ
# Shift Double Quadword Right Logical
| Opcode | Mnemonic | Description |
|---|---|---|
| 66 0F 73 /3 ib | PSRLDQ xmm1, imm8 | Shift xmm1 right by imm8 while shifting in 0s. |
# Description
Shifts the destination operand (first operand) to the right by the number of bytes specified in the count operand (second operand). The empty high-order bytes are cleared (set to all 0s). If the value specified by the count operand is greater than 15, the destination operand is set to all 0s.
The destination operand is an XMM register. The count operand is an 8-bit immediate.
# Operation
Temporary = Count;
if(Temporary > 15) Temporary = 16;
Destination = Destination >> (Temporary * 8);
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# Flags affected
None.
| Instruction | Latency | Throughput | Execution Unit |
|---|---|---|---|
| CPUID | 0F3n/0F2n/069n | 0F3n/0F2n/069n | 0F2n |
| PSRLDQ xmm, imm8 | 4/4/4 | 2/2/4 | MMX_SHFT |