/**
* Triggers an error at compilation time if the condition is true.
*/
-#ifndef __OPTIMIZE__
#define RTE_BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
-#else
-extern int RTE_BUILD_BUG_ON_detected_error;
-#define RTE_BUILD_BUG_ON(condition) do { \
- ((void)sizeof(char[1 - 2*!!(condition)])); \
- if (condition) \
- RTE_BUILD_BUG_ON_detected_error = 1; \
-} while(0)
-#endif
/**
* Combines 32b inputs most significant set bits into the least
return (uint32_t)__builtin_ctz(v);
}
+/**
+ * Searches the input parameter for the least significant set bit
+ * (starting from zero). Safe version (checks for input parameter being zero).
+ *
+ * @warning ``pos`` must be a valid pointer. It is not checked!
+ *
+ * @param v
+ * The input parameter.
+ * @param pos
+ * If ``v`` was not 0, this value will contain position of least significant
+ * bit within the input parameter.
+ * @return
+ * Returns 0 if ``v`` was 0, otherwise returns 1.
+ */
+static inline int
+rte_bsf32_safe(uint64_t v, uint32_t *pos)
+{
+ if (v == 0)
+ return 0;
+
+ *pos = rte_bsf32(v);
+ return 1;
+}
+
/**
* Return the rounded-up log2 of a integer.
*
return rte_bsf32(v);
}
+
+/**
+ * Return the last (most-significant) bit set.
+ *
+ * @note The last (most significant) bit is at position 32.
+ * @note rte_fls_u32(0) = 0, rte_fls_u32(1) = 1, rte_fls_u32(0x80000000) = 32
+ *
+ * @param x
+ * The input parameter.
+ * @return
+ * The last (most-significant) bit set, or 0 if the input is 0.
+ */
+static inline int
+rte_fls_u32(uint32_t x)
+{
+ return (x == 0) ? 0 : 32 - __builtin_clz(x);
+}
+
+/**
+ * Searches the input parameter for the least significant set bit
+ * (starting from zero).
+ * If a least significant 1 bit is found, its bit index is returned.
+ * If the content of the input parameter is zero, then the content of the return
+ * value is undefined.
+ * @param v
+ * input parameter, should not be zero.
+ * @return
+ * least significant set bit in the input parameter.
+ */
+static inline int
+rte_bsf64(uint64_t v)
+{
+ return (uint32_t)__builtin_ctzll(v);
+}
+
+/**
+ * Searches the input parameter for the least significant set bit
+ * (starting from zero). Safe version (checks for input parameter being zero).
+ *
+ * @warning ``pos`` must be a valid pointer. It is not checked!
+ *
+ * @param v
+ * The input parameter.
+ * @param pos
+ * If ``v`` was not 0, this value will contain position of least significant
+ * bit within the input parameter.
+ * @return
+ * Returns 0 if ``v`` was 0, otherwise returns 1.
+ */
+static inline int
+rte_bsf64_safe(uint64_t v, uint32_t *pos)
+{
+ if (v == 0)
+ return 0;
+
+ *pos = rte_bsf64(v);
+ return 1;
+}
+
+/**
+ * Return the last (most-significant) bit set.
+ *
+ * @note The last (most significant) bit is at position 64.
+ * @note rte_fls_u64(0) = 0, rte_fls_u64(1) = 1,
+ * rte_fls_u64(0x8000000000000000) = 64
+ *
+ * @param x
+ * The input parameter.
+ * @return
+ * The last (most-significant) bit set, or 0 if the input is 0.
+ */
+static inline int
+rte_fls_u64(uint64_t x)
+{
+ return (x == 0) ? 0 : 64 - __builtin_clzll(x);
+}
+
+/**
+ * Return the rounded-up log2 of a 64-bit integer.
+ *
+ * @param v
+ * The input parameter.
+ * @return
+ * The rounded-up log2 of the input, or 0 if the input is 0.
+ */
+static inline uint32_t
+rte_log2_u64(uint64_t v)
+{
+ if (v == 0)
+ return 0;
+ v = rte_align64pow2(v);
+ /* we checked for v being 0 already, so no undefined behavior */
+ return rte_bsf64(v);
+}
+
#ifndef offsetof
/** Return the offset of a field in a structure. */
#define offsetof(TYPE, MEMBER) __builtin_offsetof (TYPE, MEMBER)