TST Instruction

Purpose:Arithmetic compare of a scaler quantity to 0
Format:opcode src.rx
Operation:src compared to 0;
Condition
Codes:		 N <- src LSS 0;
Z <- src EQL 0;
V <- 0;
C <- 0;
Exceptions:None (Integer);
Reserved Operand (Floating Point)
Opcodes:
95TSTBTest Byte
B5TSTWTest Word
D5TSTLTest Long
53TSTFTest Float
73TSTDTest Double
Description: The source operand is compared with 0. The source operand is unaffected. The only action is to affect the codition codes.
Notes:
1.
TSTx src is equivalent to CMPx src, #0, but is one byte shorter.
2.
On a floating reserved operand fault, the condition codes are unpredictable.