[RFC PATCH v2 01/33] eal: add more min/max helpers

Bruce Richardson
2025-11-07T15:51:01Z

From: Stephen Hemminger <stephen@networkplumber.org>

Add RTE_MIN3() to handle case of RTE_MIN(RTE_MIN(...)), and similarly
add RTE_MAX3(). Change name of local temporary variables in RTE_MAX()
to allow for combinations of RTE_MIN(RTE_MAX(...)) without causing
shadow declaration warnings.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
lib/eal/include/rte_common.h | 31 ++++++++++++++++++++++++++++---
1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/lib/eal/include/rte_common.h b/lib/eal/include/rte_common.h
index 9e7d84f929..36400e8e43 100644
--- a/lib/eal/include/rte_common.h
+++ b/lib/eal/include/rte_common.h
@@ -799,6 +799,19 @@ __extension__ typedef uint64_t RTE_MARKER64[0];
_a < _b ? _a : _b; \
})

+/**
+ * Macro to return the minimum of three numbers
+ */
+#define RTE_MIN3(a, b, c) \
+ __extension__ ({ \
+ typeof (a) _a = (a); \
+ typeof (b) _b = (b); \
+ typeof (c) _c = (c); \
+ _a < _b ? (_a < _c ? _a : _c) \
+ : (_b < _c ? _b : _c); \
+ })
+
+
/**
* Macro to return the minimum of two numbers
*
@@ -814,9 +827,21 @@ __extension__ typedef uint64_t RTE_MARKER64[0];
*/
#define RTE_MAX(a, b) \
__extension__ ({ \
- typeof (a) _a = (a); \
- typeof (b) _b = (b); \
- _a > _b ? _a : _b; \
+ typeof (a) _ax = (a); \
+ typeof (b) _bx = (b); \
+ _ax > _bx ? _ax : _bx; \
+ })
+
+/**
+ * Macro to return the maximum of three numbers
+ */
+#define RTE_MAX3(a, b, c) \
+ __extension__ ({ \
+ typeof (a) _a = (a); \
+ typeof (b) _b = (b); \
+ typeof (c) _c = (c); \
+ _a > _b ? (_a > _c ? _a : _c) \
+ : (_b > _c ? _b : _c); \
})

/**
--
2.48.1