I agree that using fused multiply-add in almost all cases improves the accuracy of the results. Nevertheless, I consider that a compiler option that gives you

I agree that using fused multiply-add in almost all cases improves the accuracy of the results. Nevertheless, I consider that a compiler option that gives you good FMA, but only together with bad behavior at underflows, is something exceedingly stupid. FMA is a standard operation, while ignoring underflows is rightly prohibited by the floating-point standard. There should never have been a compiler option that mixes standard operations with non-standard operations. In C or C++, you can use the "fma" function to get FMA where desired. This is more awkward, but it is safe. Any better solution requires a change in the programming language. For instance, it could be required that adjacent * and + must always be contracted into an FMA, unless separated by parentheses. This would allow the programmer to select between FMA and FMUL+FADD, as desired. FMA has appeared in 1990 (in IBM POWER) and it has been the greatest advance in floating-point computation after the introduction of Intel 8087 in 1980 (which has resulted in the IEEE standard a few years later). It is weird that 34 years later, most, if not all, programming languages do not handle well the generation of FMA operations.