cmpxchg16b

Compare and Exchange 16 Bytes

CMPXCHG16B m128

Atomically compares 128-bit memory with RDX:RAX.

Details

The Compare and Exchange 16 Bytes instruction atomically compares 128-bit memory with RDX:RAX.

Pseudocode Operation

// Atomically compares 128-bit memory with RDX:RAX

Example

CMPXCHG16B [rbp-16]

Encoding

Binary Layout
0F
+0
C7
+1
ModRM
+2
 
Format Base (64-bit)
Opcode 0F C7 /1
Extension Base (64-bit)

Operands

  • dest
    128-bit memory operand