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Re: Need graph coloring code
- To: Michael Meissner <meissner at cygnus dot com>
- Subject: Re: Need graph coloring code
- From: Igor Markov <imarkov at umich dot edu>
- Date: Mon, 22 Jan 2001 20:44:51 -0500
- CC: gcc at gcc dot gnu dot org
- Organization: U. of Michigan, EECS
- References: <3A6CDA50.6A7C408B@umich.edu> <20010122203636.E29264@cse.cygnus.com>
I am no patent attorney, but it appears to me that
IBM could only patent a specific way to use of graph coloring
for register allocation, not the very idea to use graph coloring for it.
Otherwise, T.J. Watson would probably have patented
the use of machines to do business :)
Michael Meissner wrote:
> On Mon, Jan 22, 2001 at 08:11:44PM -0500, Igor Markov wrote:
> > If anyone needs high-performance high-quality source-code
> > to solve the optimization version of the [graph-theoretic]
> > graph coloring problem, take a look at
> > http://vlsicad.cs.ucla.edu/GSRC/bookshelf/Slots/GraphColoring/
> > These codes are not mine, but, knowing the authors, I hope that
> > there will be no difficult copyright issues if the codes turn useful
> > for gcc.
> > As I recall, the paper by D. Kirovski and M. Potkonjak describing graph
> > coloring algos used in those codes was published in Proc. Design Automation
> > Conf. in 1998 and is available online from http://www.cs.ucla.edu/~darko/
> > (Darko now works for MSFT).
> But the problem is IBM *patented* the use of graph coloring for register
> allocation, which trumps copyright.
> Michael Meissner, Red Hat, Inc. (GCC group)
> PMB 198, 174 Littleton Road #3, Westford, Massachusetts 01886, USA
> Work: firstname.lastname@example.org phone: +1 978-486-9304
> Non-work: email@example.com fax: +1 978-692-4482
Igor Markov (734) 936-7829 EECS 2211