Hi Andy,
On Mon, 12 Jun 2023 17:10:40 +0300 Andy Shevchenko andy.shevchenko@gmail.com wrote:
On Mon, Jun 12, 2023 at 3:30 PM Herve Codina herve.codina@bootlin.com wrote:
Introduce min_array() (resp max_array()) in order to get the minimal (resp maximum) of values present in an array.
Some comments below, after addressing them, Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com
Signed-off-by: Herve Codina herve.codina@bootlin.com
include/linux/minmax.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)
diff --git a/include/linux/minmax.h b/include/linux/minmax.h index 396df1121bff..37a211f22404 100644 --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -133,6 +133,32 @@ */ #define max_t(type, x, y) __careful_cmp((type)(x), (type)(y), >)
+#define __minmax_array(op, array, len) ({ \
Maybe it's my MUA, maybe the code contains spaces, can you switch to TABs if it's the case?
typeof(array) __array = (array); \We have __must_be_array()
Using __must_be_array() will lead to some failure. Indeed, we can have: --- 8< --- int *buff ... min = min_array(buff, nb_item); --- 8< ---
In this case, __must_be_array() will report that buff is not an array.
To avoid any confusion, what do you think if I renamed {min,max}_array() to {min,max}_buffer() and replace __array by __buff and use *(__buff + xxx) instead of array[xxx] in the macro.
This will lead to: --- 8< --- #define __minmax_buffer(op, buff, len) ({ \ typeof(buff) __buff = (buff); \ typeof(len) __len = (len); \ typeof(*buff + 0) __element = *(__buff + --__len); \ while (__len--) \ __element = op(__element, *(__buff + __len])); \ __element; })
#define min_buffer(buffer, len) __minmax_array(min, buffer, len) #define max_buffer(buffer, len) __minmax_array(max, buffer, len) --- 8< ---
Regards, Hervé
You will need to fix the inclusions in minmax.h at the same time, it needs linux/build_bug.h (which includes compiler.h needed for __UNIQUE_ID() and for the above mentioned one).
typeof(len) __len = (len); \typeof(*__array + 0) __element = __array[--__len]; \After above, this can be written as __array[0].
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