[PATCH 08/45] C++: Implement abs() as an inline template function

From: David Howells
Date: Sun Apr 01 2018 - 16:41:09 EST


Implement abs() as an C++ inline template function as that greatly
simplifies the source.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

include/linux/kernel.h | 19 +++++--------------
1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index e779a7487c34..59089f76c7d8 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -246,20 +246,11 @@ extern int _cond_resched(void);
*
* Return: an absolute value of x.
*/
-#define abs(x) __abs_choose_expr(x, long long, \
- __abs_choose_expr(x, long, \
- __abs_choose_expr(x, int, \
- __abs_choose_expr(x, short, \
- __abs_choose_expr(x, char, \
- __builtin_choose_expr( \
- __builtin_types_compatible_p(typeof(x), char), \
- (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
- ((void)0)))))))
-
-#define __abs_choose_expr(x, type, other) __builtin_choose_expr( \
- __builtin_types_compatible_p(typeof(x), signed type) || \
- __builtin_types_compatible_p(typeof(x), unsigned type), \
- ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
+template<typename T>
+static inline T abs(T v)
+{
+ return v < 0 ? -v : v;
+}

/**
* reciprocal_scale - "scale" a value into range [0, ep_ro)