Index

AUTIA, AUTIA1716, AUTIASP, AUTIAZ, AUTIZA

Authenticate Instruction address, using key A. This instruction authenticates an instruction address, using a modifier and key A.

If the authentication passes, the upper bits of the address are restored to enable subsequent use of the address. For information on behavior if the authentication fails, see Faulting on pointer authentication.

The address is:

The modifier is:

If FEAT_PAuth_LR is implemented and PSTATE.PACM is 1, then AUTIA1716 and AUTIASP include a second modifier that is:

It has encodings from 2 classes: Integer and System

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 1 0 0 Rn Rd

AUTIA (Z == 0)

AUTIA <Xd>, <Xn|SP>

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

AUTIZA <Xd>

boolean source_is_sp = FALSE;
boolean autia1716 = FALSE;
integer d = UInt(Rd);
integer n = UInt(Rn);

if !IsFeatureImplemented(FEAT_PAuth) then
    UNDEFINED;

if Z == '0' then // AUTIA
    if n == 31 then source_is_sp = TRUE;
else // AUTIZA
    if n != 31 then UNDEFINED;

System
(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 0 1 0 1 0 0 0 0 0 0 1 1 0 0 1 0 0 0 x 1 1 0 x 1 1 1 1 1
CRm op2

AUTIA1716 (CRm == 0001 && op2 == 100)

AUTIA1716

AUTIASP (CRm == 0011 && op2 == 101)

AUTIASP

AUTIAZ (CRm == 0011 && op2 == 100)

AUTIAZ

integer d;
integer n;
boolean source_is_sp = FALSE;
boolean autia1716 = FALSE;

case CRm:op2 of
    when '0011 100'    // AUTIAZ
        d = 30;
        n = 31;
    when '0011 101'    // AUTIASP
        d = 30;
        source_is_sp = TRUE;
    when '0001 100'    // AUTIA1716
        d = 17;
        n = 16;
        autia1716 = TRUE;
    when '0001 000' SEE "PACIA";
    when '0001 010' SEE "PACIB";
    when '0001 110' SEE "AUTIB";
    when '0011 00x' SEE "PACIA";
    when '0011 01x' SEE "PACIB";
    when '0011 11x' SEE "AUTIB";
    when '0000 111' SEE "XPACLRI";
    otherwise SEE "HINT";

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 IsFeatureImplemented(FEAT_PAuth) then
    if source_is_sp then
        if IsFeatureImplemented(FEAT_PAuth_LR) && PSTATE.PACM == '1' then
            X[d, 64] = AuthIA2(X[d, 64], SP[], X[16, 64], FALSE);
        else
            X[d, 64] = AuthIA(X[d, 64], SP[], FALSE);
    else
        if IsFeatureImplemented(FEAT_PAuth_LR) && PSTATE.PACM == '1' && autia1716 then
            X[d, 64] = AuthIA2(X[d, 64], X[n, 64], X[15, 64], FALSE);
        else
            X[d, 64] = AuthIA(X[d, 64], X[n, 64], FALSE);