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 class

(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	0	1	1	Rn					Rd
sf		S									opcode2

PACDB encoding

(Z == 0)

PACDB <Xd>, <Xn|SP>

PACDZB encoding

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

PACDZB <Xd>

Decode (all encodings)

if !IsFeatureImplemented(FEAT_PAuth) then EndOfDecode(Decode_UNDEF); boolean source_is_sp = FALSE; constant integer d = UInt(Rd); constant integer n = UInt(Rn); if Z == '0' then // PACDB if n == 31 then source_is_sp = TRUE; else // PACDZB if n != 31 then EndOfDecode(Decode_UNDEF);

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, 64] = AddPACDB(X[d, 64], SP[64]); else X[d, 64] = AddPACDB(X[d, 64], X[n, 64]);

This site is provided as a community resource and is NOT affiliated with nor endorsed by Arm Limited.