TFLTNZ

Test bit and fault if nonzero

This instruction compares the value of a bit in a general-purpose register with zero, and conditionally generates a Conditional fault exception if the comparison is not equal. This instruction does not affect condition flags.

Fault class

(FEAT_CFLT)

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
b5	1	1	1	0	1	1	0	b40					0	0	0	0	0	0	0	imm2		1	0	0	1	1	Rt
																										op

Encoding

TFLTNZ #<reason>, <R><t>, #<imm>

Decode

if !IsFeatureImplemented(FEAT_CFLT) then EndOfDecode(Decode_UNDEF); end; let datasize : integer{} = 32 << UInt(b5); let t : integer = UInt(Rt); let bit_pos : integer = UInt(b5::b40); let reason : bits(16) = ZeroExtend{}(imm2);

Assembler Symbols

Is a 2-bit unsigned immediate, in the range 0 to 3, encoded in the "imm2" field.

<R>

Is a width specifier, encoded in b5:

b5	<R>
0	W
1	X

In assembler source code an 'X' specifier is always permitted, but a 'W' specifier is permitted only when the bit number is less than 32.

<t>	Is the number [0-30] of the general-purpose register to be tested or the name ZR (31), encoded in the "Rt" field.

<imm>

Is the bit number to be tested, in the range 0 to 63, encoded in "b5:b40".

Operation

CheckCFLTEnabled(); let operand : bits(datasize) = X{}(t); if operand[bit_pos] != '0' then let isflt : boolean = FALSE; AArch64_ConditionalFault(isflt, reason); end;