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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:

  • In the general-purpose register or stack pointer that is specified by <Xn|SP> for PACDB.
  • The value zero, for PACDZB.

Integer
(Armv8.3)

313029282726252423222120191817161514131211109876543210
110110101100000100Z011RnRd

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 !HavePACExt() 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] = AddPACDB(X[d], SP[]);
else
    X[d] = AddPACDB(X[d], X[n]);
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