From: Oleg Nesterov <oleg@redhat.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
behlendorf1@llnl.gov
Subject: Re: [PATCH] remove abs64()
Date: Wed, 13 Apr 2011 16:27:03 +0200 [thread overview]
Message-ID: <20110413142703.GA1511@redhat.com> (raw)
In-Reply-To: <20110412210045.GA19901@p183>
On 04/13, Alexey Dobriyan wrote:
>
> +#define abs(x) \
> +({ \
> + typeof(x) _x = (x); \
> + \
> + __builtin_choose_expr( \
> + __builtin_types_compatible_p(typeof(_x), signed char), \
> + (unsigned char)({ _x < 0 ? -_x : _x; }), \
> + __builtin_choose_expr( \
> + __builtin_types_compatible_p(typeof(_x), short), \
> + (unsigned short)({ _x < 0 ? -_x : _x; }), \
> + __builtin_choose_expr( \
> + __builtin_types_compatible_p(typeof(_x), int), \
> + (unsigned int)({ _x < 0 ? -_x : _x; }), \
> + __builtin_choose_expr( \
> + __builtin_types_compatible_p(typeof(_x), long), \
> + (unsigned long)({ _x < 0 ? -_x : _x; }), \
> + __builtin_choose_expr( \
> + __builtin_types_compatible_p(typeof(_x), long long), \
> + (unsigned long long)({ _x < 0 ? -_x : _x; }), \
> + _x))))); \
> +})
Personally I agree.
But, we have some stupid users which do something like abs(u32_value)
and expecting that abs() should treat this value as "signed".
Oleg.
next prev parent reply other threads:[~2011-04-13 14:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-12 21:00 [PATCH] remove abs64() Alexey Dobriyan
2011-04-12 21:07 ` Randy Dunlap
2011-04-12 21:10 ` Andrew Morton
2011-04-12 21:16 ` Alexey Dobriyan
2011-04-12 21:33 ` Andrew Morton
2011-04-12 21:40 ` Randy Dunlap
2011-04-12 21:14 ` Alexey Dobriyan
2011-04-13 14:27 ` Oleg Nesterov [this message]
2011-04-13 18:48 ` Andrew Morton
2011-04-13 20:20 ` Oleg Nesterov
2011-04-13 20:26 ` Andrew Morton
2011-04-13 20:36 ` Alexey Dobriyan
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