A.5.21 CLFLUSH: Flush Cache Line
CLFLUSH mem ; 0F AE /7 [WILLAMETTE,SSE2]
CLFLUSH invalidates the cache line that contains the linear address
specified by the source operand from all levels of the processor
cache hierarchy (data and instruction). If, at any level of the cache
hierarchy, the line is inconsistent with memory (dirty) it is written to
memory before invalidation. The source operand points to a byte-sized
memory location.
Although CLFLUSH is flagged SSE2 and above, it may not be present on all
processors which have SSE2 support, and it may be supported on other
processors; the CPUID instruction (section A.5.34) will return a bit
which indicates support for the CLFLUSH instruction.