If you do not specify -xalias_level, the compiler sets the option to -xalias_level=any. If you specify -xalias_level but do not provide a value, the compiler sets the option to -xalias_level=compatible.
The compiler does not perform type-based alias analysis at optimization level -xO2 and below.
If you are using reinterpret_cast or an equivalent old-style cast, the program may violate the assumptions of the analysis. Also, union type punning, as shown in the following example, violates the assumptions of the analysis.
union bitbucket{ int i; float f; }; int bitsof(float f){ bitbucket var; var.f=3.6; return var.i; } |