XPACD, XPACI, XPACLRI

Strip Pointer Authentication Code

This instruction removes the Pointer Authentication Code from an address. The address is in the specified general-purpose register for XPACI and XPACD, and is in LR for XPACLRI.

The XPACD instruction is used for data addresses, and XPACI and XPACLRI are used for instruction addresses.

Encoding: Integer

Variants: FEAT_PAuth (ARMv8.3)

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	1	0	0	0		1	1	1	1	1
sf		S									opcode2										D	Rn					Rd

XPACD (D == 1)

XPACD <Xd>

XPACI (D == 0)

XPACI <Xd>

Decoding algorithm

if !IsFeatureImplemented(FEAT_PAuth) then EndOfDecode(Decode_UNDEF);
constant integer d = UInt(Rd);
constant boolean data = (D == '1');

Encoding: System

Variants: FEAT_PAuth (ARMv8.3)

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	0	0	1	1	1	1	1	1	1	1
																				CRm				op2

XPACLRI

Decoding algorithm

if !IsFeatureImplemented(FEAT_PAuth) then EndOfDecode(Decode_NOP);
constant integer d = 30;
constant boolean data = FALSE;

Operation

X[d, 64] = Strip(X[d, 64], data);

Explanations

<Xd>: Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.