STLLRB

Store LORelease register byte

This instruction stores a byte from a 32-bit register to a memory location. The instruction also has memory ordering semantics as described in Load LOAcquire, Store LORelease. For information about addressing modes, see Load/Store addressing modes.

Encoding: No offset

Variants: FEAT_LOR (PROFILE_A)

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
0	0	0	0	1	0	0	0	1	0	0	(1)	(1)	(1)	(1)	(1)	0	(1)	(1)	(1)	(1)	(1)
size									L		Rs					o0	Rt2					Rn					Rt

STLLRB <Wt>, [<Xn|SP>{, #0}]

Decoding algorithm

if !IsFeatureImplemented(FEAT_LOR) then EndOfDecode(Decode_UNDEF);
constant integer t = UInt(Rt);
constant integer n = UInt(Rn);
constant boolean tagchecked = n != 31;

Operation

bits(64) address;

constant AccessDescriptor accdesc = CreateAccDescLOR(MemOp_STORE, tagchecked);

if n == 31 then
    CheckSPAlignment();
    address = SP[64];
else
    address = X[n, 64];

Mem[address, 1, accdesc] = X[t, 8];

Explanations

<Wt>: Is the 32-bit name of the general-purpose register to be transferred, encoded in the "Rt" field.
<Xn|SP>: Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field.

Operational Notes

If PSTATE.DIT is 1, the timing of this instruction is insensitive to the value of the data being loaded or stored.