SETF8, SETF16

Evaluation of 8-bit or 16-bit flag values

This instruction sets the PSTATE.NZV flags based on the value in the specified general-purpose register. SETF8 treats the value as an 8-bit value. SETF16 treats the value as a 16-bit value.

The PSTATE.C flag is not affected by these instructions.

Integer class

(FEAT_FlagM)

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	1	1	1	0	1	0	0	0	0	0	0	0	0	0	0	sz	0	0	1	0	Rn					0	1	1	0	1
sf	op	S									opcode2																o3	mask

SETF8 encoding

(sz == 0)

SETF8 <Wn>

SETF16 encoding

(sz == 1)

SETF16 <Wn>

Decode (all encodings)

if !IsFeatureImplemented(FEAT_FlagM) then EndOfDecode(Decode_UNDEF); constant integer size = 8 << UInt(sz); constant integer n = UInt(Rn);

Assembler Symbols

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

Operation

constant bits(32) reg = X[n, 32]; PSTATE.N = reg<size-1>; PSTATE.Z = if (reg<size-1:0> == Zeros(size)) then '1' else '0'; PSTATE.V = reg<size> EOR reg<size-1>; //PSTATE.C unchanged;

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.

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