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From: Lawrence D'Oliveiro <ldo@nz.invalid>
Newsgroups: comp.lang.c
Subject: Re: technology discussion =?UTF-8?B?4oaS?= does the world need a
 "new" C ?
Date: Thu, 11 Jul 2024 02:51:39 -0000 (UTC)
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On Wed, 10 Jul 2024 03:16:18 -0400, James Kuyper wrote:

> On 7/9/24 20:57, Lawrence D'Oliveiro wrote:
>
>> On Sat, 6 Jul 2024 21:34:29 -0400, James Kuyper wrote:
>> 
>>> On many platforms, if _Alignof(type) is less than the word size, then
>>> a C pointer to that type is implemented as the combination of the
>>> machine address of the correct word, combined with an offset within
>>> that word of the first byte of that object.
>> 
>> Which is a terrific idea, except it cannot be carried to its logical 
>> conclusion (addressing of arbitrarily-aligned dynamically-defined 
>> bitfields) because of the requirement in the C spec that the size of a 
>> “byte” be at least 8 bits.
> 
> I will grant you that I failed to mention the fact that this is a
> feasible way of implementing C only on platforms with a word size of 16
> bits or longer.

Don’t you think C needs a better way of handling bitfields than shift-and-
mask? Many architectures have bitfield instructions, but C cannot easily 
make use of them without the ability to have arbitrarily-bit-aligned 
pointers.