Le 23/06/2023 à 10:58, Herve Codina a écrit :
Introduce min_array() (resp max_array()) in order to get the minimal (resp maximum) of values present in an array.
Signed-off-by: Herve Codina herve.codina@bootlin.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com
Reviewed-by: Christophe Leroy christophe.leroy@csgroup.eu
include/linux/minmax.h | 64 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+)
diff --git a/include/linux/minmax.h b/include/linux/minmax.h index 396df1121bff..798c6963909f 100644 --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -133,6 +133,70 @@ */ #define max_t(type, x, y) __careful_cmp((type)(x), (type)(y), >)
+/*
- Remove a const qualifier from integer types
- _Generic(foo, type-name: association, ..., default: association) performs a
- comparison against the foo type (not the qualified type).
- Do not use the const keyword in the type-name as it will not match the
- unqualified type of foo.
- */
+#define __unconst_integer_type_cases(type) \
- unsigned type: (unsigned type)0, \
- signed type: (signed type)0
+#define __unconst_integer_typeof(x) typeof( \
- _Generic((x), \
char: (char)0, \__unconst_integer_type_cases(char), \__unconst_integer_type_cases(short), \__unconst_integer_type_cases(int), \__unconst_integer_type_cases(long), \__unconst_integer_type_cases(long long), \default: (x)))+/*
- Do not check the array parameter using __must_be_array().
- In the following legit use-case where the "array" passed is a simple pointer,
- __must_be_array() will return a failure.
- --- 8< ---
- int *buff
- ...
- min = min_array(buff, nb_items);
- --- 8< ---
- The first typeof(&(array)[0]) is needed in order to support arrays of both
- 'int *buff' and 'int buff[N]' types.
- The array can be an array of const items.
- typeof() keeps the const qualifier. Use __unconst_integer_typeof() in order
- to discard the const qualifier for the __element variable.
- */
+#define __minmax_array(op, array, len) ({ \
- typeof(&(array)[0]) __array = (array); \
- typeof(len) __len = (len); \
- __unconst_integer_typeof(__array[0]) __element = __array[--__len]; \
- while (__len--) \
__element = op(__element, __array[__len]); \- __element; })
+/**
- min_array - return minimum of values present in an array
- @array: array
- @len: array length
- Note that @len must not be zero (empty array).
- */
+#define min_array(array, len) __minmax_array(min, array, len)
+/**
- max_array - return maximum of values present in an array
- @array: array
- @len: array length
- Note that @len must not be zero (empty array).
- */
+#define max_array(array, len) __minmax_array(max, array, len)
- /**
- clamp_t - return a value clamped to a given range using a given type
- @type: the type of variable to use