This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: BITS_PER_UNIT larger than 8 -- word addressing
- From: Ian Lance Taylor <iant at google dot com>
- To: Boris Boesler <baembel at gmx dot de>
- Cc: GCC <gcc at gcc dot gnu dot org>
- Date: 05 Dec 2007 13:32:35 -0800
- Subject: Re: BITS_PER_UNIT larger than 8 -- word addressing
- References: <2649CC51-1ACF-4C2B-88BA-396CB39D4BEE@gmx.de>
Boris Boesler <baembel@gmx.de> writes:
> I assume that GCC internals assume that memory can be byte (8 bits)
> addressed - for historical reasons.
No. gcc internals assume that memory can be addressed in units of
size BITS_PER_UNIT. The default for BITS_PER_UNIT is 8. I have
written backends for machines for which that is not true.
It is unusual, and there is only one official target with
BITS_PER_UNIT != 8 (c4x), so there is often some minor breakage.
Ian