Aliasing in Fortran

As described in the section “Inhibitors of localization”, an alias is an alternate name for some object. Fortran EQUIVALENCE statements, C pointers, and procedure calls in both languages can potentially cause aliasing problems. The examples presented in Chapter 3 concern aliasing problems that occur at optimization levels +O3 and above. However, code motion can also cause aliasing problems at optimization levels +O1 and above.