ARM and Thumb instructions can execute conditionally on the condition flags set by a previous instruction.
The conditional instruction can occur either:
The instructions that you can make conditional
depends on whether the processor is in ARM state or Thumb state.
To make an instruction conditional, you must add a condition
code suffix to the instruction mnemonic. The condition code suffix
enables the processor to test a condition based on the flags. If
the condition test of a conditional instruction fails, the instruction:
Does not execute.
Does not write any value to its destination register.
Does not affect any of the flags.
Does not generate any exception.