linux-kernel - Re: The type of bitops

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Message-ID: <CALCETrVMwbFbAo1OHtuuAKstTG9S-v78taNh4b_AUtwnUmdYfA@mail.gmail.com>
Date:	Tue, 7 May 2013 16:36:13 -0700
From:	Andy Lutomirski <luto@...capital.net>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	linux-arch <linux-arch@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: The type of bitops

On Tue, May 7, 2013 at 4:18 PM, H. Peter Anvin <hpa@...or.com> wrote:
> On 05/07/2013 04:17 PM, Andy Lutomirski wrote:
>>
>> The one and only time I tried to use this, I thought this was odd.  Long
>> has a different size on 32 vs 64 bit architectures, and bit ops seem
>> like they'd want to be the same size everywhere so you can allocate the
>> appropriate number of bits.  (Also, if you only want 32 bits, you have
>> to do some evil cheating, and I don't trust casting int* to long* on
>> big-endian architectures.)
>>
>> Would offering a u32* option make sense?
>>
>
> Honestly, the only thing that makes sense on bigendian architectures is
> either byte-by-byte elements or counting bit numbers from the MSB, but
> that is serious water under the bridge at this point...

Sure... but would some important data structure that only need 32 bits
get shorter if there were 32-bit bitops?

--Andy
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