STNP
Store pair of registers, with non-temporal hint
This instruction
calculates an address from a base register value and an immediate offset,
and stores two 32-bit words or two 64-bit doublewords to the calculated address,
from two registers.
For information about addressing modes, see
Load/Store addressing modes.
For information about non-temporal pair instructions, see
Load/Store non-temporal pair.
If PSTATE.DIT is 1, the timing of this instruction is insensitive to the value of the data being loaded or stored.
x
0
1
0
1
0
0
0
0
0
0
STNP <Wt1>, <Wt2>, [<Xn|SP>{, #<imm>}]
1
STNP <Xt1>, <Xt2>, [<Xn|SP>{, #<imm>}]
// Empty.
<Wt1>
Is the 32-bit name of the first general-purpose register to be transferred, encoded in the "Rt" field.
<Wt2>
Is the 32-bit name of the second general-purpose register to be transferred, encoded in the "Rt2" field.
<Xn|SP>
Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field.
<imm>
For the 32-bit variant: is the optional signed immediate byte offset, a multiple of 4 in the range -256 to 252, defaulting to 0 and encoded in the "imm7" field as <imm>/4.
<imm>
For the 64-bit variant: is the optional signed immediate byte offset, a multiple of 8 in the range -512 to 504, defaulting to 0 and encoded in the "imm7" field as <imm>/8.
<Xt1>
Is the 64-bit name of the first general-purpose register to be transferred, encoded in the "Rt" field.
<Xt2>
Is the 64-bit name of the second general-purpose register to be transferred, encoded in the "Rt2" field.
if opc<0> == '1' then UNDEFINED;
constant integer t = UInt(Rt);
constant integer t2 = UInt(Rt2);
constant integer n = UInt(Rn);
constant boolean nontemporal = TRUE;
constant integer scale = 2 + UInt(opc<1>);
constant integer datasize = 8 << scale;
constant bits(64) offset = LSL(SignExtend(imm7, 64), scale);
constant boolean tagchecked = n != 31;
bits(64) address;
bits(64) address2;
constant integer dbytes = datasize DIV 8;
constant boolean privileged = PSTATE.EL != EL0;
constant AccessDescriptor accdesc = CreateAccDescGPR(MemOp_STORE, nontemporal, privileged,
tagchecked);
if n == 31 then
CheckSPAlignment();
address = SP[];
else
address = X[n, 64];
address = AddressAdd(address, offset, accdesc);
address2 = AddressIncrement(address, dbytes, accdesc);
Mem[address , dbytes, accdesc] = X[t, datasize];
Mem[address2, dbytes, accdesc] = X[t2, datasize];