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:

• In the general-purpose register that is specified by <Xd> for AUTIA and AUTIZA.
• In X17, for AUTIA1716.
• In X30, for AUTIASP and AUTIAZ.

The modifier is:

• In the general-purpose register or stack pointer that is specified by <Xn|SP> for AUTIA.
• The value zero, for AUTIZA and AUTIAZ.
• In X16, for AUTIA1716.
• In SP, for AUTIASP.

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

• In X15, for AUTIA1716.
• In X16, for AUTIASP.

It has encodings from 2 classes: Integer and System

Integer
(FEAT_PAuth)

if !IsFeatureImplemented(FEAT_PAuth) then UNDEFINED; if Z == '1' && Rn != '11111' then UNDEFINED; boolean autia1716 = FALSE; integer d = UInt(Rd); integer n = UInt(Rn); boolean auth_combined = FALSE; boolean source_is_sp = Z == '0' && n == 31;

System
(FEAT_PAuth)

if !IsFeatureImplemented(FEAT_PAuth) then EndOfInstruction(); // Instruction executes as NOP integer d; integer n; boolean source_is_sp = FALSE; boolean autia1716 = FALSE; boolean auth_combined = 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";