[PATCH v2 5/8] minmax: Factor out the zero-extension logic from umin/umax.

David Laight
2024-07-28T14:22:25Z

The '+ 0u + 0ul + 0ull' to zero extend to 64bit on both 32bit and
64bit systems was replicated 4 times.
Factor out and then join up some 'not overlong' lines.

Signed-off-by: David Laight <david.laight@aculab.com>
---
v2 - no change

include/linux/minmax.h | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/include/linux/minmax.h b/include/linux/minmax.h
index b9b5348a3879..a0c948ad576d 100644
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -72,22 +72,26 @@
*/
#define max(x, y) __careful_cmp(max, x, y)

+/*
+ * Zero extend a non-negative value to 64bits.
+ * Undefined for negative values.
+ * The extension to 64 bits is often optimised away.
+ */
+#define __zero_extend(x) ((x) + 0u + 0ul + 0ull)
+
/**
* umin - return minimum of two non-negative values
- * Signed types are zero extended to match a larger unsigned type.
* @x: first value
* @y: second value
*/
-#define umin(x, y) \
- __careful_cmp(min, (x) + 0u + 0ul + 0ull, (y) + 0u + 0ul + 0ull)
+#define umin(x, y) __careful_cmp(min, __zero_extend(x), __zero_extend(y))

/**
* umax - return maximum of two non-negative values
* @x: first value
* @y: second value
*/
-#define umax(x, y) \
- __careful_cmp(max, (x) + 0u + 0ul + 0ull, (y) + 0u + 0ul + 0ull)
+#define umax(x, y) __careful_cmp(max, __zero_extend(x), __zero_extend(y))

/**
* min3 - return minimum of three values
--
2.17.1

-
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