On Fri, 18 Apr 2008 21:56:38 -0400, Alan Lehotsky <[EMAIL PROTECTED]> wrote: >Martin, > >I did a port of GCC to the Analog Devices SHARC chip. I ended up supporting 3 >kinds of pointers for this chip (two for address >spaces and one for byte pointers - the chip itself is only word addressable >(although words can be from 16 to 48 bits in size >depending on what memory is being accessed.) > >I also worked on the Bliss-36 compiler at DEC, so I'm well acquainted with the >PDP10 architecture. > >I don't have access to any 10/20 HW, but I'd be happy to act as a >reviewer/advisor to your changes. > >Al Lehotsky > >On Apr 18, 2008, at 20:21, Martin Chaney wrote: >> >> Hi, >> >> I'm am the proprietor of a gcc compiler for the PDP10 architecture. >> >> (This is a compiler previously worked on by Lars Brinkhoff who left XKL some >>while before I joined XKL. It's possible some of you may have been familiar with >>him or the compiler from that time.) >> >> The compiler is currently in a state where it is synched with the both the 4.3 >>and 4.4 branches, and it passes the testsuite tests (with the exception of some >>I've flagged as expected failures for the pdp10). >> >> My employer is happy to release my work on the gcc compiler back to the >>gcc community and I've sent in a request for the necessary forms. >> >> The PDP10 architecture is unusual in various ways that distinguish it from >>the mainstream architectures supported by the gcc compiler and this has >>made the development of this compiler a significant task. Undoubtedly I've >>made customizations in inappropriate ways. I'm seeking contacts with people >>who might be able to advise me on how to cleanup my implementation to >>reduce the amount of #ifdef __PDP10_H__ I've sprinkled liberally throughout the >>source. Also, if its possible to get simple changes made to prevent breaking >>my PDP10 version and that are otherwise innocuous that would be wonderful. >>For example, the PDP10 word size is 36 bits; Fairly recently people have taken >>to writing code that assumes word size is a power of 2 even when it's >>straightforward to write in a manner that doesn't make that assumption. >> >> Considering the large number of files customized to get the PDP10 compiler >>working, I'm not sure whether it's possible to get it to build directly from the gcc >>trunk, but it would be nice to work toward that goal. >> >> Some other things which distinguish the PDP10 architecture from >>assumptions in the gcc code base include: its variety of formats of pointers >>only one of which can be viewed as an integer and that one is capable of >>referencing only word aligned data, a functional difference between signed and >>unsigned integers, and peculiarities to the use of PDP10 byte arrays which are >>very difficult to describe. >> >> Any help or advise would be appreciated. >> >> Martin Chaney >> XKL, LLC
In http://pdp-10.trailing-edge.com/ there are ~6.5GB about PDP10 files where inside ~1.5GB are tapes in tap.bz2 format. It's a lot of obsolete software of more >20 years ago, it's only for hobbies because you won't find archaic 36 bit machines, and all the current modern machines are 32 and 64 bit.
