The rapid adoption of low-precision arithmetic in artificial intelligence and edge computing has created a strong demand for energy-efficient and flexible floating-point multiply-accumulate (MAC) units. This paper presents a dual-precision floating-point MAC processing element supporting FP8 (E4M3, E5M2) and FP4 (2 x E2M1, 2 x E1M2) formats, specifically optimized for low-power and high-throughput AI workloads. The proposed architecture employs a novel bit-partitioning technique that enables a single 4-bit unit multiplier to operate either as a standard 4 x 4 multiplier for FP8 or as two parallel 2 x 2 multipliers for 2-bit operands, achieving maximum hardware utilization without duplicating logic. Implemented in 28 nm technology, the proposed PE achieves an operating frequency of 1.94 GHz with an area of 0.00396 mm^2 and power consumption of 2.13 mW, resulting in up to 60.4% area reduction and 86.6% power savings compared to state-of-the-art designs, making it well suited for energy-constrained AI inference and mixed-precision computing applications when deployed within larger accelerator architectures.