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Re: Bug#285396: [ARM] wide chars don't work

[I am not subscribed to debian-arm.]

On Tue, Jan 11, 2005 at 11:03:59PM +0000, Phil Blundell wrote:
> On Tue, 2005-01-11 at 12:37 -0500, Branden Robinson wrote:
> > Here are his remarks, recast a bit from IRC-speak into something more
> > conventional.
> > 
> >   GCC on ARM is doing something different from every other C compiler I've
> >   seen.  It may not deviate from what the C specification allows, but it
> >   appears to deviate from common practice.  The ARM folks would find code
> >   would work with fewer problems if they fixed GCC to behave like other C
> >   compilers do.  Having an array of structs of a byte each usually forces
> >   16 bit alignment only on other compilers I've seen.
> Jim is correct.  This behaviour of the ARM compiler seemed like a good
> idea in 1988, but subsequent experience has shown that it was a mistake
> to pad structs in this way.
> Changing the default behaviour of the compiler definitely would result
> in ABI breakage for some programs.  We plan to take care of this, and a
> variety of other historical goofs, by switching to the new ARM "EABI".
> This change will involve a flag day at some point during the next Debian
> release cycle, but will result in better performance (by a factor of
> more than 10 for some code) and greater compatibility with other
> architectures.
> > I'm also curious to know if xterm has always had this problem on Debian
> > ARM, or if it has cropped up only with recent revisions of GCC.  Can anyone
> > tell me?
> I don't have any direct experience of the bug, but from the description
> I've seen it sounds like it would always have been this way.  GCC's
> behaviour certainly hasn't changed recently.

Since the discussion seems to have died down:

I am reaching the conclusion that I'm going to need to apply the patch more
or less as written.  It can have a lot of #if guards around it, but it
sounds like for GNU C and the ARM architecture until this new "EABI"
happens[1], this is just something that will have to be done if we want X
to work right on Debian/ARM.

Jim, do I read this correctly?

[1] ...even then it would no doubt have to be kept around for a while,
thanks to people not migrating to the new ABI.

G. Branden Robinson                |    Those who fail to remember the laws
Debian GNU/Linux                   |    of science are condemned to
branden@debian.org                 |    rediscover some of the worst ones.
http://people.debian.org/~branden/ |    -- Harold Gordon

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