You copied the Doc URL to your clipboard.

ARM Compiler armasm User Guide : PRFM (register)

PRFM (register)

Prefetch memory (register offset).

Syntax

PRFM prfop, [Xn|SP, Rm{, extend {amount}}]

Where:

prfop

Is the prefetch operation, and contains the following fields without spaces between them:

type target policy

type

Can be one of:

Table 17-15 PRFM (register) type options

option meaning
PLD prefetch for load
PST prefetch for store
target

Can be one of:

Table 17-16 PRFM (register) target options

option meaning
L1 Level 1 cache
L2 Level 2 cache
L3 Level 3 cache
policy

Can be one of:

Table 17-17 PRFM (register) policy options

option meaning
KEEP keep in cache
STRM Streaming data

For example, PLDL1KEEP.

Xn|SP

Is the 64-bit name of the general-purpose base register or stack pointer.

R

Is the index width specifier, and can be either W or X.

m

Is the number [0-30] of the general-purpose index register or the name ZR (31).

extend

Is the index extend/shift specifier, defaulting to LSL, and can be one of the values shown in Usage.

amount

Is the index shift amount, optional and defaulting to #0 when extend is not LSL, and can be either #0 or #3.

Usage

The following table shows the valid specifier combinations:

Table 17-18 PRFM specifier combinations

R extend
W SXTW
W UXTW
X LSL
X SXTX
Was this page helpful? Yes No