Authenticate instruction address, using key B
This instruction authenticates an instruction address, using a modifier and key B.
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 AUTIB1716 and AUTIBSP include a second modifier that is:
It has encodings from 2 classes: Integer and System
| 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 | 1 | Rn | Rd | ||||||||
| sf | S | opcode2 | |||||||||||||||||||||||||||||
AUTIZB <Xd>
if !IsFeatureImplemented(FEAT_PAuth) then EndOfDecode(Decode_UNDEF); if Z == '1' && Rn != '11111' then EndOfDecode(Decode_UNDEF); constant boolean autib1716 = FALSE; constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant boolean auth_combined = FALSE; constant boolean source_is_sp = Z == '0' && n == 31;
| 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 | 1 | x | 1 | 1 | 1 | 1 | 1 |
| CRm | op2 | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_PAuth) then EndOfDecode(Decode_NOP); integer d; integer n; boolean source_is_sp = FALSE; boolean autib1716 = FALSE; constant boolean auth_combined = FALSE; case CRm:op2 of when '0011 110' // AUTIBZ d = 30; n = 31; when '0011 111' // AUTIBSP d = 30; source_is_sp = TRUE; when '0001 110' // AUTIB1716 d = 17; n = 16; autib1716 = TRUE;
| <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. |
if source_is_sp then if IsFeatureImplemented(FEAT_PAuth_LR) && PSTATE.PACM == '1' then X[d, 64] = AuthIB2(X[d, 64], SP[64], X[16, 64], auth_combined); else X[d, 64] = AuthIB(X[d, 64], SP[64], auth_combined); else if IsFeatureImplemented(FEAT_PAuth_LR) && PSTATE.PACM == '1' && autib1716 then X[d, 64] = AuthIB2(X[d, 64], X[n, 64], X[15, 64], auth_combined); else X[d, 64] = AuthIB(X[d, 64], X[n, 64], auth_combined);
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