Index

PACDB, PACDZB

Pointer Authentication Code for Data address, using key B. This instruction computes and inserts a pointer authentication code for a data address, using a modifier and key B.

The address is in the general-purpose register that is specified by <Xd>.

The modifier is:

Integer
(FEAT_PAuth)

31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 0 1 1 0 1 0 1 1 0 0 0 0 0 1 0 0 Z 0 1 1 Rn Rd

PACDB (Z == 0)

PACDB <Xd>, <Xn|SP>

PACDZB (Z == 1 && Rn == 11111)

PACDZB <Xd>

boolean source_is_sp = FALSE;
integer d = UInt(Rd);
integer n = UInt(Rn);

if !IsFeatureImplemented(FEAT_PAuth) then
    UNDEFINED;

if Z == '0' then // PACDB
    if n == 31 then source_is_sp = TRUE;
else // PACDZB
    if n != 31 then UNDEFINED;

Assembler Symbols

<Xd>

Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.
<Xn|SP>

Is the 64-bit name of the general-purpose source register or stack pointer, encoded in the "Rn" field.

Operation

if source_is_sp then
    X[d, 64] = AddPACDB(X[d, 64], SP[]);
else
    X[d, 64] = AddPACDB(X[d, 64], X[n, 64]);