Open Watcom Fortran compiler help needed 
Author Message
 Open Watcom Fortran compiler help needed

The Open Watcom open source compiler project,  www.openwatcom.org ,
needs help in improving the fortran compiler from F77 to F90/F95/F2k3.
Also needed is help in porting the Fortran compiler runtime library to
Linux and to AMD64.  Most of the compiler internals and runtime library
are written in C code.  The Open Watcom compilers and linker currently
support Dos16, Dos32, Win16, Win32, OS/2 and Netware 4.  The Linux
porting project is about 75% complete but needs a lot of "cleanup".

An article on improving the C and C++ compilers is at
    http://www.*-*-*.com/ ; Please note that any code
generation improvements in the C and C++ compilers will automatically
accrue to the Fortran compiler since all the Open Watcom compilers use
the same code generator and code optimizer.

The Fortran compiler is currently at the F77 level but already has many
F90 improvements added.  A few other improvements are also needed
such as the Integer*8, Logical*8 and Real*16 data types.

Now is your chance to get experience working on what used to to be
the premier compiler for the PC environment.   With a lot of work <g>,
that place can be regained.

Sincerely,
Lynn McGuire



Sat, 19 Jul 2008 00:05:40 GMT  
 Open Watcom Fortran compiler help needed


Quote:
> The Open Watcom open source compiler project,  www.openwatcom.org ,
> needs help in improving the Fortran compiler from F77 to F90/F95/F2k3.
> Also needed is help in porting the Fortran compiler runtime library to
> Linux and to AMD64.  Most of the compiler internals and runtime library
> are written in C code.  The Open Watcom compilers and linker currently
> support Dos16, Dos32, Win16, Win32, OS/2 and Netware 4.  The Linux
> porting project is about 75% complete but needs a lot of "cleanup".

> An article on improving the C and C++ compilers is at
>    http://www.theinquirer.net/?article=29332 .   Please note that any code
> generation improvements in the C and C++ compilers will automatically
> accrue to the Fortran compiler since all the Open Watcom compilers use
> the same code generator and code optimizer.

> The Fortran compiler is currently at the F77 level but already has many
> F90 improvements added.  A few other improvements are also needed
> such as the Integer*8, Logical*8 and Real*16 data types.

> Now is your chance to get experience working on what used to to be
> the premier compiler for the PC environment.   With a lot of work <g>,
> that place can be regained.

> Sincerely,
> Lynn McGuire

My skills are not compiler development, so I'm probably not much use - but
but I'm puzzled about OpenWatcom:

*    What kind of people are using the Fortran compiler?
            Supporting legacy Watcom Fortran code, with Watcom extensions?
(and not really interested in any real development in the compiler?)
            Doing any new work in Watcom Fortran?

* Can the OpenWatcom project inherit any code from GNU Fortran of g95?

* Should OpenWatcom consider dropping the Fortran and trying to make
themselves compatible with GNU GCC, so that gfortran & g95 can just plug in?

* Why would you want LOGICAL * 8? Why not just LOGICAL? I can understand
INTEGER * 8 and REAL * 16; is there already underlying support in the
compiler back-end?



Sat, 19 Jul 2008 07:34:49 GMT  
 Open Watcom Fortran compiler help needed

Quote:
>* Why would you want LOGICAL * 8? Why not just LOGICAL? I can understand
>INTEGER * 8 and REAL * 16; is there already underlying support in the
>compiler back-end?

There are legacy codes that equivalence (i.e., map, union) INTEGER and LOGICAL onto
the same storage.  Having identical lengths avoids array index funnies.


Sat, 19 Jul 2008 08:44:12 GMT  
 Open Watcom Fortran compiler help needed

Quote:
>*    What kind of people are using the Fortran compiler?
>            Supporting legacy Watcom Fortran code, with Watcom extensions?
>(and not really interested in any real development in the compiler?)
>            Doing any new work in Watcom Fortran?

Yes, no and Yes.

It is not "not interested in any real development in the compiler", it is rather
too steep a learning curve for most Fortran people to make effective contributions.
At least those of us with day jobs. ;-)  And then there are some, like me, with
multiple day jobs ;-), and the resulting serious lack of spare time.

The C and C++ sides are being upgraded, the F77 side (relatively) languishes.

Quote:
>* Should OpenWatcom consider dropping the Fortran and trying to make
>themselves compatible with GNU GCC, so that gfortran & g95 can just plug in?

With all due respect - Blecchh!  GNU compilers are fine and dandy, but they
aren't the same.  FOr one thing, those of us who need embedded dev support
(and think that embedded 32 bit OSes are grotesque overkill for many things)
enjoy the 16 bit real mode DOS support.  GNU compilers really won't do anything
less than 32 bits, even DJDelorie abandoned his 16 port attempts (LONG ago).

The GNU compiler suites have certain strengths and weaknesses, OW has a different
mix of these.



Sat, 19 Jul 2008 08:50:52 GMT  
 Open Watcom Fortran compiler help needed

Quote:
> *    What kind of people are using the Fortran compiler?
>            Supporting legacy Watcom Fortran code, with Watcom extensions?
> (and not really interested in any real development in the compiler?)

Yup, you got us.  I have fixed a couple of bugs in the runtime library
but that is it.  Dont know about the other users.  BTW, we build our
calculation engine with OW: 550,000 lines of f77 code and 10,000
lines of c code.

Quote:
>            Doing any new work in Watcom Fortran?

All the time for us.   But we may move to to Intel Fortran someday since
the compiler is somewhat better (more diagnostics) and can be built
with Visual C++ (we may merge our calculation engine and our C++ user
interface - and moon is made of green cheese <g>).

Quote:
> * Can the OpenWatcom project inherit any code from GNU Fortran of g95?

Dont have a clue but I highly doubt it.

Quote:
> * Should OpenWatcom consider dropping the Fortran and trying to make

It may happen.  The source code maintainer would like to reduce the
scope of OW.

Quote:
> themselves compatible with GNU GCC, so that gfortran & g95 can just plug in?

That might be a whole lot of work.  I have heard the OW de{*filter*} is
much better than GDB though.  Supposedly the OW de{*filter*} is
already compatible with GCC on Linux (but I have not witnessed this).

Quote:
> * Why would you want LOGICAL * 8? Why not just LOGICAL? I can understand
> INTEGER * 8 and REAL * 16; is there already underlying support in the
> compiler back-end?

So that you can:
        integer*8 intarrary (100)
        logical*8 logarray (100)
        equivalence (intarray, logarray)

Yes and No, OW C supports I*8 but it does not support R*16 (that I know of).

BTW, did I mention that the code to build Open Watcom is over 1,000,000
lines of code. 1.95 GB and contains a couple of internal languages ?  The
OW compilers generate "intermediate" code which the code generator
converts into optimized / unoptimized machine language.

Lynn



Sat, 19 Jul 2008 09:08:31 GMT  
 
 [ 5 post ] 

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