dstst

Data Stream Touch for Store

dstst RA, RB, STRM

Initiates a prefetch for writing.

Details

Initiates a hardware prefetch stream for data that is likely to be written in the near future. The instruction computes an effective address from RA and RB and hints to the memory subsystem to begin preparing the cache line for write-back operations with the temporal locality specified by STRM. This is an advisory instruction supporting store-stream prefetching.

Pseudocode Operation

EA ← (RA | 0) + RB; InitiateDataStream(EA, STRM, isStore=1, isTransient=0)

Example

dstst r4, r5, 0

Encoding

Binary Layout
31
0
STRM
6
RA
11
RB
16
374
21
/
31
 
Format X-form
Opcode 0x7C0002EC
Extension Base

Operands

  • RA
    Base
  • RB
    Index
  • STRM
    Stream ID