* - a global variable and a local one never alias (R1 b)
* - a global variable and a TLS one never alias (R1 c)
* - a local variable and a TLS one never alias (R1 d)
+ * - a local variable and a parameter never alias (R1 e)
* - two different variables never alias (R2)
* - if one is a variable which address has never taken
* there is no alias (R3)