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Subject[PATCH 1/2] kernel.h: add {min,max}3 macros
Date
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.

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Ingo Molnar <mingo@elte.hu>
---
include/linux/kernel.h | 16 ++++++++++++++++
1 files changed, 16 insertions(+), 0 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2b0a35e..9a9b52c 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -640,6 +640,22 @@ 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 == &_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 == &_max3); \
+ _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
+ (_max2 > _max3 ? _max2 : _max3); })
+
/**
* clamp - return a value clamped to a given range with strict typechecking
* @val: current value
--
1.7.2.1.95.g3d045.dirty


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