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Re: Alignment requirement of basic types

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John Temples <usenet@xargs-spam.com> wrote:
> On 2015-04-03, James Kuyper <jameskuyper@verizon.net> wrote:
>> C2011 requires that alignments must be powers of 2, no such requirement
>> existed in earlier versions of the C standard. I've no idea whether
>> there's ever been an implementation of C where that wasn't the case.
 
> I have used 8-bit platforms with C compilers that supported 24-bit
> integer and floating point types.  These platforms had no alignment
> requirements for multi-byte objects, so it was possible to have
> objects aligned on a three-byte boundary.

It would be interesting to have a machine with 24 bit int that
required 3 byte (multiple of three) alignment. I suppose it isn't
so hard to build a 24 bit wide memory with byte addressing.

I have wondered about cache systems using other than power of two
interleave. 

Fortran allows for any integer base greater than 1, so one could
have a trinary computer with trinary addressing, and multiple of
three alignment.

There have been decimal computers with decimal addressing, but 
I believe with no alignment requirement.

-- glen

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Alignment requirement of basic types Noob <root@127.0.0.1> - 2015-04-03 15:48 +0200
  Re: Alignment requirement of basic types Tim Prince <tprince@computer.org> - 2015-04-03 10:23 -0400
  Re: Alignment requirement of basic types James Kuyper <jameskuyper@verizon.net> - 2015-04-03 11:37 -0400
    Re: Alignment requirement of basic types John Temples <usenet@xargs-spam.com> - 2015-04-03 17:21 +0000
      Re: Alignment requirement of basic types James Kuyper <jameskuyper@verizon.net> - 2015-04-03 13:45 -0400
        Re: Alignment requirement of basic types Kaz Kylheku <kaz@kylheku.com> - 2015-04-03 18:40 +0000
      Re: Alignment requirement of basic types Keith Thompson <kst-u@mib.org> - 2015-04-03 10:50 -0700
      Re: Alignment requirement of basic types glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-04-03 19:02 +0000
    Re: Alignment requirement of basic types Kaz Kylheku <kaz@kylheku.com> - 2015-04-03 18:01 +0000
  Re: Alignment requirement of basic types Richard Damon <Richard@Damon-Family.org> - 2015-04-03 12:05 -0400
    Re: Alignment requirement of basic types glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-04-03 16:48 +0000
  Re: Alignment requirement of basic types Kaz Kylheku <kaz@kylheku.com> - 2015-04-03 16:46 +0000
    Re: Alignment requirement of basic types Keith Thompson <kst-u@mib.org> - 2015-04-03 11:06 -0700
      Re: Alignment requirement of basic types Robert Wessel <robertwessel2@yahoo.com> - 2015-04-05 22:22 -0500
  Re: Alignment requirement of basic types Waldek Hebisch <hebisch@antispam.uni.wroc.pl> - 2015-04-04 23:15 +0000

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