The Fortran standard does not specify anything about passing by references or value. Instead, it specifies the expected results. The compilers do it however the

The Fortran standard does not specify anything about passing by references or value. Instead, it specifies the expected results. The compilers do it however they want or can, which means that they can pass pointers, values, copies, or pointers to copies depending on the situation. Sometimes (most of the time, to be fair), the compiler can work out the best solution. Sometimes, the developer has to jump through some hoops to avoid unnecessary copies.