A processor for floating point underflow detection includes circuitry to decode a first instruction and a floating point unit. The decoded instruction, when executed by the processor, may be for performing a fused multiply-add (FMA) operation. The floating point unit includes circuitry to determine a non-normalized result of the first instruction based on a first input, a second input, and a third input. The floating point unit further includes circuitry to determine whether underflow exists in the non-normalized result based on a first exponent of the first input, a second exponent of the second input, and a third exponent of the third input.