Fused multiply-add (fma) low functional unit

Abstract

An example processor includes a register and a fused multiply-add (FMA) low functional unit. The register stores first, second, and third floating point (FP) values. The FMA low functional unit receives a request to perform an FMA low operation: multiplies the first FP value with the second FP value to obtain a first product value; adds the first product with the third FP value to generate a first result value; rounds the first result to generate a first FMA value; multiplies the first FP value with the second FP value to obtain a second product value; adds the second product value with the third FP value to generate a second result value; and subtracts the FMA value from the second result value to obtain a third result value, which can then be normalized and rounded (FMA low result) and sent the FMA low result to an application.