-qfloat=nomaf

The nomaf option is provided for cases where it is necessary to exactly duplicate the double results of an implementation that does not have multiply-add operations. The nomaf option prevents the compiler from generating any multiply-add operations. Not using multiply-add operations decreases accuracy and performance but strictly conforms to the IEEE standard for double-precision arithmetic.

To duplicate the single-precision results from other implementations, you may also need to use the -qfloat=rndsngl option.

Overview
-qfloat=hssngl
-qfloat=nans
-qfloat=hsflt
-qfloat=rndsngl
-qflttrap

Sample TRAP Exception Handler

float Compiler Option
flttrap Compiler Option