Commit f27c85c5 authored Oct 26, 2010 by Hagen Paul Pfeifer Committed by Linus Torvalds Oct 26, 2010

kernel.h: add {min,max}3 macros



Introduce two additional min/max macros to compare three operands.  This
will save some cycles as well as some bytes on the stack and last but not
least more pleasing as macro nesting.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent c5c6dd4e

include/linux/kernel.h

+18 −0

Original line number	Diff line number	Diff line
		@@ -651,6 +651,24 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
		(void) (&_max1 == &_max2); \
		_max1 > _max2 ? _max1 : _max2; })

		#define min3(x, y, z) ({ \
		typeof(x) _min1 = (x); \
		typeof(y) _min2 = (y); \
		typeof(z) _min3 = (z); \
		(void) (&_min1 == &_min2); \
		(void) (&_min1 == &_min3); \
		_min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
		(_min2 < _min3 ? _min2 : _min3); })

		#define max3(x, y, z) ({ \
		typeof(x) _max1 = (x); \
		typeof(y) _max2 = (y); \
		typeof(z) _max3 = (z); \
		(void) (&_max1 == &_max2); \
		(void) (&_max1 == &_max3); \
		_max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
		(_max2 > _max3 ? _max2 : _max3); })

		/**
		* min_not_zero - return the minimum that is _not_ zero, unless both are zero
		* @x: value1

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