Write Back Cache Line

Encoding

EncodingOperand
mModRM.r/m[w]

Description

The CLWB instruction writes back the cache line (if modified) containing m8 into main memory. The data may remain in the cache line afterwards, but this is not guaranteed.

Operation

public void CLWB(IntPtr addr)
{
    CacheLineWriteBack(addr)
}

Flags Affected

None.

Intrinsics

Exceptions

Real-Address Mode

#UD
  • If the
  • LOCK
  • prefix is used.
#SS(0)
  • If a memory operand using the
  • SS
  • segment has an effective address that is outside the
  • SS
  • segment's limit.
#GP(0)
  • If a memory operand (using a segment other than
  • SS
  • ) has an effective address that is outside the segment's limit.

Virtual-8086 Mode

#UD
  • If the
  • LOCK
  • prefix is used.
#SS(0)
  • If a memory operand using the
  • SS
  • segment has an effective address that is outside the
  • SS
  • segment's limit.
#GP(0)
  • If a memory operand (using a segment other than
  • SS
  • ) has an effective address that is outside the segment's limit.
#PF(fc)
  • If a page fault occurs.

Protected Mode

#UD
  • If the
  • LOCK
  • prefix is used.
#SS(0)
  • If a memory operand using the
  • SS
  • segment has an effective address that is outside the
  • SS
  • segment's limit.
#GP(0)
  • If the destination is located in a non-writable segment.
  • If a memory operand uses a segment containing a NULL selector.
  • If a memory operand (using a segment other than SS) has an effective address that is outside the segment's limit.
#PF(fc)
  • If a page fault occurs.

Compatibility Mode

#UD
  • If the
  • LOCK
  • prefix is used.
#SS(0)
  • If a memory operand using the
  • SS
  • segment has an effective address that is outside the
  • SS
  • segment's limit.
#GP(0)
  • If the destination is located in a non-writable segment.
  • If a memory operand uses a segment containing a NULL selector.
  • If a memory operand (using a segment other than SS) has an effective address that is outside the segment's limit.
#PF(fc)
  • If a page fault occurs.

Long Mode

#UD
  • If the
  • LOCK
  • prefix is used.
#SS(0)
  • If a memory operand using the SS segment is in non-canonical form.
  • If a memory operand using the SS segment has an effective address that is outside the SS segment's limit.
#GP(0)
  • If a memory operand (using a segment other than SS) is in non-canonical form.
  • If the destination is located in a non-writable segment.
  • If a memory operand uses a segment containing a NULL selector.
  • If a memory operand (using a segment other than SS) has an effective address that is outside the segment's limit.
#PF(fc)
  • If a page fault occurs.