include/linux/minmax.h

1 /* SPDX-License-Identifier: GPL-2.0 */
13  * - Avoid multiple evaluations of the arguments (so side-effects like
14  *   "x++" happen only once) when non-constant.
15  * - Retain result as a constant expressions when called with only
18  * - Perform signed v unsigned type-checking (to generate compile
20  * - Unsigned char/short are always promoted to signed int and can be
22  * - Unsigned arguments can be compared against non-negative signed constants.
23  * - Comparison of a signed argument against an unsigned constant fails
34 /* True for a non-negative signed int constant */
36 	(__builtin_choose_expr(__is_constexpr(x) && __is_signed(x), x, -1) >= 0)
56 	__builtin_choose_expr(__is_constexpr((x) - (y)),	\
75 	__builtin_choose_expr(__is_constexpr((val) - (lo) + (hi)),	\
81  * min - return minimum of two values of the same or compatible types
82  * @x: first value
83  * @y: second value
88  * max - return maximum of two values of the same or compatible types
89  * @x: first value
90  * @y: second value
95  * umin - return minimum of two non-negative values
97  * @x: first value
98  * @y: second value
104  * umax - return maximum of two non-negative values
105  * @x: first value
106  * @y: second value
112  * min3 - return minimum of three values
113  * @x: first value
114  * @y: second value
115  * @z: third value
120  * max3 - return maximum of three values
121  * @x: first value
122  * @y: second value
123  * @z: third value
128  * min_not_zero - return the minimum that is _not_ zero, unless both are zero
138  * clamp - return a value clamped to a given range with strict typechecking
139  * @val: current value
140  * @lo: lowest allowable value
141  * @hi: highest allowable value
156  * min_t - return minimum of two values, using the specified type
158  * @x: first value
159  * @y: second value
164  * max_t - return maximum of two values, using the specified type
166  * @x: first value
167  * @y: second value
173  * In the following legit use-case where the "array" passed is a simple pointer,
175  * --- 8< ---
179  * --- 8< ---
191 	__unqual_scalar_typeof(__array[0]) __element = __array[--__len];\
192 	while (__len--)							\
197  * min_array - return minimum of values present in an array
206  * max_array - return maximum of values present in an array
215  * clamp_t - return a value clamped to a given range using a given type
217  * @val: current value
218  * @lo: minimum allowable value
219  * @hi: maximum allowable value
227  * clamp_val - return a value clamped to a given range using val's type
228  * @val: current value
229  * @lo: minimum allowable value
230  * @hi: maximum allowable value
239 static inline bool in_range64(u64 val, u64 start, u64 len)  in in_range64()  argument
241 	return (val - start) < len;  in in_range64()
244 static inline bool in_range32(u32 val, u32 start, u32 len)  in in_range32()  argument
246 	return (val - start) < len;  in in_range32()
250  * in_range - Determine if a value lies within a range.
251  * @val: Value to test.
252  * @start: First value in range.
255  * This is more efficient than "if (start <= val && val < (start + len))".
256  * It also gives a different answer if @start + @len overflows the size of
258  * which behaviour you want, or prove that start + len never overflow.
261 #define in_range(val, start, len)					\  argument
262 	((sizeof(start) | sizeof(len) | sizeof(val)) <= sizeof(u32) ?	\
263 		in_range32(val, start, len) : in_range64(val, start, len))
266  * swap - swap values of @a and @b
267  * @a: first value
268  * @b: second value