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From: Joe Perches <joe@perches.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Jean Delvare <khali@linux-fr.org>,
	"Darrick J. Wong" <djwong@us.ibm.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	lm-sensors <lm-sensors@lm-sensors.org>
Subject: Re: [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do
Date: Tue, 11 Nov 2008 18:51:50 +0000	[thread overview]
Message-ID: <1226429510.10478.1061.camel@localhost> (raw)
In-Reply-To: <20081111090702.94be2a19.akpm@linux-foundation.org>

On Tue, 2008-11-11 at 09:07 -0800, Andrew Morton wrote:
> On Tue, 11 Nov 2008 11:04:54 +0100 Jean Delvare <khali@linux-fr.org> wrote:
> > On Mon, 10 Nov 2008 17:01:32 -0800, Darrick J. Wong wrote:
> > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> > > index fba141d..fb02266 100644
> > > --- a/include/linux/kernel.h
> > > +++ b/include/linux/kernel.h
> > > @@ -48,6 +48,12 @@ extern const char linux_proc_banner[];
> > >  #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
> > >  #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
> > >  #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
> > > +#define DIV_ROUND_CLOSEST(x, divisor)(			\
> > > +{							\
> > > +	typeof(divisor) __divisor = divisor;		\
> > > +	(((x) + ((__divisor) / 2)) / (__divisor));	\
> > > +}							\
> > > +) 
> > I don't get why you implement this as a macro rather than an inline
> > function? A function would look much better.
> The idea is that DIV_ROUND_CLOSEST() can be used with arguments of any
> size (char, short, ...  long long) and will do all the suitable
> promotion and will return a type of the appropriate width and
> signedness.

Perhaps the macro should be placed directly after
DIV_ROUND_UP and should use the same argument naming.

Perhaps HALF_UP is more descriptive and fairly common.
http://java.sun.com/j2se/1.5.0/docs/api/java/math/RoundingMode.html



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WARNING: multiple messages have this Message-ID (diff)
From: Joe Perches <joe@perches.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Jean Delvare <khali@linux-fr.org>,
	"Darrick J. Wong" <djwong@us.ibm.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	lm-sensors <lm-sensors@lm-sensors.org>
Subject: Re: [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with  rounding
Date: Tue, 11 Nov 2008 10:51:50 -0800	[thread overview]
Message-ID: <1226429510.10478.1061.camel@localhost> (raw)
In-Reply-To: <20081111090702.94be2a19.akpm@linux-foundation.org>

On Tue, 2008-11-11 at 09:07 -0800, Andrew Morton wrote:
> On Tue, 11 Nov 2008 11:04:54 +0100 Jean Delvare <khali@linux-fr.org> wrote:
> > On Mon, 10 Nov 2008 17:01:32 -0800, Darrick J. Wong wrote:
> > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> > > index fba141d..fb02266 100644
> > > --- a/include/linux/kernel.h
> > > +++ b/include/linux/kernel.h
> > > @@ -48,6 +48,12 @@ extern const char linux_proc_banner[];
> > >  #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
> > >  #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
> > >  #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
> > > +#define DIV_ROUND_CLOSEST(x, divisor)(			\
> > > +{							\
> > > +	typeof(divisor) __divisor = divisor;		\
> > > +	(((x) + ((__divisor) / 2)) / (__divisor));	\
> > > +}							\
> > > +) 
> > I don't get why you implement this as a macro rather than an inline
> > function? A function would look much better.
> The idea is that DIV_ROUND_CLOSEST() can be used with arguments of any
> size (char, short, ...  long long) and will do all the suitable
> promotion and will return a type of the appropriate width and
> signedness.

Perhaps the macro should be placed directly after
DIV_ROUND_UP and should use the same argument naming.

Perhaps HALF_UP is more descriptive and fairly common.
http://java.sun.com/j2se/1.5.0/docs/api/java/math/RoundingMode.html



  parent reply	other threads:[~2008-11-11 18:51 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-11  1:01 [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Darrick J. Wong
2008-11-11  1:01 ` [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Darrick J. Wong
2008-11-11  1:01 ` [lm-sensors] [PATCH 2/2] adt74{62, 70, Darrick J. Wong
2008-11-11  1:01   ` [PATCH 2/2] adt74{62, 70, 73}: Use DIV_ROUND_CLOSEST for rounded division Darrick J. Wong
2008-11-11 10:04 ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Jean Delvare
2008-11-11 10:04   ` [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Jean Delvare
2008-11-11 17:07   ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Andrew Morton
2008-11-11 17:07     ` [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Andrew Morton
2008-11-11 17:11     ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Jean Delvare
2008-11-11 17:11       ` [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Jean Delvare
2008-11-11 18:51     ` Joe Perches [this message]
2008-11-11 18:51       ` Joe Perches
2008-11-11 23:05 ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Trent Piepho
2008-11-11 23:05   ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Trent Piepho
2008-11-11 23:20   ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Andrew Morton
2008-11-11 23:20     ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Andrew Morton
2008-11-11 23:42     ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Trent Piepho
2008-11-11 23:42       ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Trent Piepho
2008-11-12  0:08       ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Andrew Morton
2008-11-12  0:08         ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Andrew Morton
2008-11-14 21:46         ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Trent Piepho
2008-11-14 21:46           ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Trent Piepho
2008-11-14 22:24           ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Andrew Morton
2008-11-14 22:24             ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Andrew Morton
2008-11-11 23:50     ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Jochen Voß
2008-11-11 23:50       ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Jochen Voß
2009-08-03 11:57 ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Peter Zijlstra
2009-08-03 11:57   ` [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Peter Zijlstra
2009-08-03 12:21   ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Jean Delvare
2009-08-03 12:21     ` [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Jean Delvare
2009-08-03 12:27     ` [lm-sensors] [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do Peter Zijlstra
2009-08-03 12:27       ` [PATCH 1/2] Create a DIV_ROUND_CLOSEST macro to do division with rounding Peter Zijlstra

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