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)

Decode for all variants of this encoding

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

System
(FEAT_PAuth)

Decode for all variants of this encoding

if !IsFeatureImplemented(FEAT_PAuth) then EndOfDecode(Decode_NOP); end; var d : integer; var n : integer; var source_is_sp : boolean = FALSE; var autia1716 : boolean = FALSE; let auth_combined : boolean = 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; end;