Re: Licensing/Media question - VMS

This is a discussion on Re: Licensing/Media question - VMS ; "Douglas A. Gwyn" wrote: |Toby Thain wrote: |> I recently read a bit about Johnson's pcc and pcc2, which had trouble |> beating Ritchie's. | |They weren't really in competition. The PCC family |was meant as a base for porting ...

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Thread: Re: Licensing/Media question

  1. Re: Licensing/Media question

    "Douglas A. Gwyn" wrote:

    |Toby Thain wrote:
    |> I recently read a bit about Johnson's pcc and pcc2, which had trouble
    |> beating Ritchie's.
    |
    |They weren't really in competition. The PCC family
    |was meant as a base for porting to various platforms,
    |sort of like GCC but much earlier.

    pcc was incredibly handy when you wanted to quickly port an application
    that depended heavily on unsigned characters or such to the 11, but it
    never produced code as fast/small as Ritchie's and the version that came
    with 2.xBSD (at least) had some nasty bugs. (Bugs like, if you incremented
    a long in a context where you wouldn't normally use a long on an 11--say
    as an array index--the arithmetic got screwed up. And of course, things
    like that showed up in programs written on vaxen by people who reasoned that
    long and int are the same, so use long everywhere.)

    Once there was a (short-lived) project to try to compile the 2.9 kernel
    with pcc so it would be easier to incorporate 4.2 code. (Yes, I realize
    that the goal in itself didn't make a lot of sense.) Beyond the spectacular
    compiler crashes and and buggy code generation, it was observed that it would
    be necessary to implement a different overlay scheme to get the resulting
    objects to even fit...

    Dan Lanciani
    ddl@danlan.*com
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  2. Re: Licensing/Media question

    Dan Lanciani wrote:
    > pcc was incredibly handy when you wanted to quickly port an application
    > that depended heavily on unsigned characters or such to the 11, ...


    Later versions of the Ritchie compiler supported the more
    recent language features, although AT&T quit supporting
    the PDP-11 around Unix System V Release 2, so that is the
    latest version I have. There were some bugs I fixed (not
    due to Dennis), some tweaks I made to work around PDP-11
    problems (e.g. upon function entry, if the function
    involves the FPU I touch the stack bottom to ensure that
    there is not a page fault in the middle of a floating
    operation, because there is not enough information
    available to the OS to correctly recover after growing
    the stack), and support for overlays (JHU/BRL PDP-11
    Unix; our implementation was slicker than the one added
    contemporaneously to 2BSD).

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