TST (immediate) -- AArch32

Test (immediate) performs a bitwise AND operation on a register value and an immediate value. It updates the condition flags based on the result, and discards the result.

It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 ) .

constant n = UInt(Rn); constant a32 = FALSE; constant bits(12) imm = i:imm3:imm8; // Armv8-A removes UNPREDICTABLE for R13 if n == 15 then UNPREDICTABLE;

Assembler Symbols

Operation

if ConditionPassed() then EncodingSpecificOperations(); constant (imm32, carry) = (if a32 then A32ExpandImm_C(imm, PSTATE.C) else T32ExpandImm_C(imm, PSTATE.C)); constant result = R[n] AND imm32; PSTATE.N = result<31>; PSTATE.Z = IsZeroBit(result); PSTATE.C = carry; // PSTATE.V unchanged

Operational information

If CPSR.DIT is 1, this instruction has passed its condition execution check, and does not use R15 as either its source or destination:

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 v01_31, pseudocode v2024-03_rel ; Build timestamp: 2024-03-25T10:05

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
!= 1111				0	0	1	1	0	0	0	1	Rn				(0)	(0)	(0)	(0)	imm12
cond

15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
1	1	1	1	0	i	0	0	0	0	0	1	Rn				0	imm3			1	1	1	1	imm8

<Rn>	For encoding A1: is the general-purpose source register, encoded in the "Rn" field. The PC can be used, but this is deprecated.
	For encoding T1: is the general-purpose source register, encoded in the "Rn" field.

<const>	For encoding A1: an immediate value. See Modified immediate constants in A32 instructions for the range of values.
	For encoding T1: an immediate value. See Modified immediate constants in T32 instructions for the range of values.