Index

ADD (immediate)

Add (immediate) adds a register value and an optionally-shifted immediate value, and writes the result to the destination register.

This instruction is used by the alias MOV (to/from SP).

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
sf 0 0 1 0 0 0 1 0 sh imm12 Rn Rd
op S

32-bit (sf == 0)

ADD <Wd|WSP>, <Wn|WSP>, #<imm>{, <shift>}

64-bit (sf == 1)

ADD <Xd|SP>, <Xn|SP>, #<imm>{, <shift>}

integer d = UInt(Rd);
integer n = UInt(Rn);
constant integer datasize = 32 << UInt(sf);
bits(datasize) imm;

case sh of
    when '0' imm = ZeroExtend(imm12, datasize);
    when '1' imm = ZeroExtend(imm12:Zeros(12), datasize);

Assembler Symbols

<Wd|WSP>

Is the 32-bit name of the destination general-purpose register or stack pointer, encoded in the "Rd" field.
<Wn|WSP>

Is the 32-bit name of the source general-purpose register or stack pointer, encoded in the "Rn" field.
<Xd|SP>

Is the 64-bit name of the destination general-purpose register or stack pointer, encoded in the "Rd" field.
<Xn|SP>

Is the 64-bit name of the source general-purpose register or stack pointer, encoded in the "Rn" field.
<imm>

Is an unsigned immediate, in the range 0 to 4095, encoded in the "imm12" field.
<shift>

Is the optional left shift to apply to the immediate, defaulting to LSL #0 and encoded in sh:

sh <shift>
0 LSL #0
1 LSL #12

Alias Conditions

Alias Is preferred when
MOV (to/from SP) sh == '0' && imm12 == '000000000000' && (Rd == '11111' || Rn == '11111')

Operation

bits(datasize) result;
bits(datasize) operand1 = if n == 31 then SP[]<datasize-1:0> else X[n, datasize];

(result, -) = AddWithCarry(operand1, imm, '0');

if d == 31 then
    SP[] = ZeroExtend(result, 64);
else
    X[d, datasize] = result;

Operational information

If PSTATE.DIT is 1: