Fused Multiply Add (FMA) was not always being disabled when the switch -ffp-contract=off was used. More specifically, FMA is enabled when -ffp-contract=fast is used, and it also is enabled implicitly with -ffast-math. The combination:
is intended to leave most of fast-math enabled (for example, leave reassociation, reciprocal transformations, etc.) enabled, but disable the use of FMA. However, FMA was incorrectly left enabled with the above switch combination. This commit fixes this, allowing users to enable most of the fast-math optimizations, while disabling the FMA feature.