Fortran compilers sometimes produce faster code for a limited subdomain of problems because fortran's language semantics are less restrictive: all arrays are as

Fortran compilers sometimes produce faster code for a limited subdomain of problems because fortran's language semantics are less restrictive: all arrays are assumed to not alias and the compiler has more freedom to reassociate arithmetic and apply other unsafe arithmetic transformations that are disallowed by C's stricter model. C compilers let you specify that you want similarly relaxed semantics via compiler flags and language keywords; however, they also allow the programmer to have stricter behavior when necessary, e.g. allowing one to operate on memory that may actually alias and still get correct behavior.