Language Extensions
-------------------
`g77' offers several extensions to FORTRAN 77 language that `f2c'
doesn't:
* Automatic arrays
* `CYCLE' and `EXIT'
* Construct names
* `SELECT CASE'
* `KIND=' and `LEN=' notation
* Semicolon as statement separator
* Constant expressions in `FORMAT' statements (such as
`FORMAT(I<J>)', where `J' is a `PARAMETER' named constant)
* `MvBits' intrinsic
* `libU77' (Unix-compatibility) library, with routines known to
compiler as intrinsics (so they work even when compiler options
are used to change the interfaces used by Fortran routines)
`g77' also implements iterative `DO' loops so that they work even in
the presence of certain "extreme" inputs, unlike `f2c'. Note:Loops.
However, `f2c' offers a few that `g77' doesn't, such as:
* Intrinsics in `PARAMETER' statements
* Array bounds expressions (such as `REAL M(N(2))')
* `AUTOMATIC' statement
It is expected that `g77' will offer some or all of these missing
features at some time in the future.