[dpdk-dev] [PATCH 01/10] eal: add API to align variable to previous power of 2
Pavan Nikhilesh
pbhagavatula at caviumnetworks.com
Fri Feb 16 22:36:51 CET 2018
Add 32b and 64b API's to align the given variable to the previous power
of 2.
Signed-off-by: Pavan Nikhilesh <pbhagavatula at caviumnetworks.com>
---
lib/librte_eal/common/include/rte_common.h | 36 ++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index c7803e41c..126914f07 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -259,6 +259,24 @@ rte_align32pow2(uint32_t x)
return x + 1;
}
+/**
+ * Aligns input parameter to the previous power of 2
+ *
+ * @param x
+ * The integer value to algin
+ *
+ * @return
+ * Input parameter aligned to the previous power of 2
+ */
+static inline uint32_t
+rte_align32lowpow2(uint32_t x)
+{
+ x = rte_align32pow2(x);
+ x--;
+
+ return x - (x >> 1);
+}
+
/**
* Aligns 64b input parameter to the next power of 2
*
@@ -282,6 +300,24 @@ rte_align64pow2(uint64_t v)
return v + 1;
}
+/**
+ * Aligns 64b input parameter to the previous power of 2
+ *
+ * @param v
+ * The 64b value to align
+ *
+ * @return
+ * Input parameter aligned to the previous power of 2
+ */
+static inline uint64_t
+rte_align64lowpow2(uint64_t v)
+{
+ v = rte_align64pow2(v);
+ v--;
+
+ return v - (v >> 1);
+}
+
/*********** Macros for calculating min and max **********/
/**
--
2.16.1
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