[PATCH 1/2] eal: add API to align integer to previous power of 2
From: Pavan Nikhilesh <hidden>
Date: 2018-02-17 10:50:07
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Add 32b and 64b API's to align the given integer to the previous power of 2. Signed-off-by: Pavan Nikhilesh <redacted> --- 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 **********/ /**
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2.16.1