ANDS (shifted register) -- A64

This instruction performs a bitwise AND of a register value and an optionally-shifted register value, and writes the result to the destination register. It updates the condition flags based on the result.

Decode for all variants of this encoding

if sf == '0' && imm6<5> == '1' then EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer datasize = 32 << UInt(sf); constant ShiftType shift_type = DecodeShift(shift); constant integer shift_amount = UInt(imm6);

Assembler Symbols

<Wd>	Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Wn>	Is the 32-bit name of the first general-purpose source register, encoded in the "Rn" field.

<Wm>	Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field.

<shift>

Is the optional shift to be applied to the final source, defaulting to LSL and encoded in shift:

shift	<shift>
00	LSL
01	LSR
10	ASR
11	ROR

<amount>	For the "32-bit" variant: is the shift amount, in the range 0 to 31, defaulting to 0 and encoded in the "imm6" field.
	For the "64-bit" variant: is the shift amount, in the range 0 to 63, defaulting to 0 and encoded in the "imm6" field.

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

<Xn>	Is the 64-bit name of the first general-purpose source register, encoded in the "Rn" field.

<Xm>	Is the 64-bit name of the second general-purpose source register, encoded in the "Rm" field.

Alias Conditions

Alias	Is preferred when
TST (shifted register)	Rd == '11111'

Operation

constant bits(datasize) operand1 = X[n, datasize]; constant bits(datasize) operand2 = ShiftReg(m, shift_type, shift_amount, datasize); constant bits(datasize) result = operand1 AND operand2; X[d, datasize] = result; PSTATE.<N,Z,C,V> = result<datasize-1>:IsZeroBit(result):'00';

Operational information

If PSTATE.DIT is 1:

The execution time of this instruction is independent of:
- The values of the data supplied in any of its registers.
- The values of the NZCV flags.
The response of this instruction to asynchronous exceptions does not vary based on:
- The values of the data supplied in any of its registers.
- The values of the NZCV flags.

Internal version only: aarchmrs v2024-12_rel, pseudocode v2024-12_rel ; Build timestamp: 2024-12-15T22:18