porting gcc/binutils

[Meissner, Michael]

The original intention was that CGEN would eventually be able to generate the MD file for GCC.  When I last used CGEN 2 years ago, it was not able to do that at the time, and I suspect the problem is very complex for real machines, because often times you have to have various tweaks that don't necessarily fit in the CGEN framework (errata, timing changes, etc.).

In terms of paperwork, if a company does not distribute GNU code, it does not have make the changes available (and if it does distribute the compiler, it only has to make the changes available to the people it distributes the compiler binaries to).  Obviously it is the best if the code is contributed back to the FSF, but there are machine ports out there that haven't been contributed for various reasons.

-----Original Message-----
From: Andrija Radičević [mailto:andrija.radicevic@zg.t-com.hr] 
Sent: Tuesday, December 20, 2005 5:43 PM
To: Meissner, Michael
Cc: gcc@gnu.org
Subject: RE: porting gcc/binutils

Hi Michael,

first, thanks for your detailed instructions

<snip>

> If your target is a regular target like a RISC platform, the CGEN system
> can be used to simplify building the instruction tables:
> http://sourceware.org/cgen/
> 
<snip>

I have already stumbled over cgen on the net and skimmed the manual. I
have noticed that it uses RTL CPU descriptions, I hope this code can be
reused for gcc machine description file.

<snip>

> If you intend to have the port contributed to the FSF, be sure you start
> your paperwork early.  If you are being paid for the work, you will need
> signatures from the appropriate corporate officers to verify that you
> are legally allowed to contribute the code.  If you are doing this in
> your spare time, make sure you know what your legal status is for code
> that you write.
> 
<snip>

I'd be happy to contribute to the FSF, so thanks for reminding me on the
legal stuff. But, since all the tools are under GPL, should't the
company be obliged to make the code public, i.e. fall under GPL
automatically ?


Andrija