Re: [PATCH] Athlon/Opteron Prefetch Fix for 2.6.0test5 + numbers

[Andreas Schwab]

kaih@xxxxxxxxxxxxxxxxx (Kai Henningsen) writes:

> ak@xxxxxxx (Andi Kleen)  wrote on 17.09.03 in <20030917211200.GA5997@xxxxxxxxxxxxx>:
>
>> On Wed, Sep 17, 2003 at 01:50:59PM -0700, Linus Torvalds wrote:
>
>> > Also, you do things like comparing pointers for less/greater than, and at
>> > least some versions of gcc has done that wrong - using signed comparisons.
>>
>> Really? Is that any version we still support (2.95+) ?
>> It is certainly legal ISO-C. I changed it for now.
>
> It certainly is *not* legal ISO C, and never was.

Certainly the kernel isn't using ISO C, and never will.

IMHO you can just compare two pointers to char in GNU C and expect to get
a meaningful result.  I think the bug Linus was thinking of was some
problems with counting loops where gcc transformed the index variable into
a pointer, but then got the terminating comparison wrong.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@xxxxxxx
SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg
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