ANDS (shifted register) -- A64

Bitwise AND (shifted register), setting flags, 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.

integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); integer datasize = if sf == '1' then 64 else 32; boolean setflags; LogicalOp op; case opc of when '00' op = LogicalOp_AND; setflags = FALSE; when '01' op = LogicalOp_ORR; setflags = FALSE; when '10' op = LogicalOp_EOR; setflags = FALSE; when '11' op = LogicalOp_AND; setflags = TRUE; if sf == '0' && imm6<5> == '1' then UNDEFINED; ShiftType shift_type = DecodeShift(shift); integer shift_amount = UInt(imm6); boolean invert = (N == '1');

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.

<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.

<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,

Alias Conditions

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

Operation

bits(datasize) operand1 = X[n]; bits(datasize) operand2 = ShiftReg(m, shift_type, shift_amount); if invert then operand2 = NOT(operand2); case op of when LogicalOp_AND result = operand1 AND operand2; when LogicalOp_ORR result = operand1 OR operand2; when LogicalOp_EOR result = operand1 EOR operand2; if setflags then PSTATE.<N,Z,C,V> = result<datasize-1>:IsZeroBit(result):'00'; X[d] = result;

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: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

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	1	1	0	1	0	1	0	shift		0	Rm					imm6						Rn					Rd
	opc									N