Add missing implementation for 64-bit fls function, and extend
unit test to test the new function as well.
Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
---
lib/librte_eal/common/include/rte_common.h | 18 ++++++++++++++++++
test/test/test_common.c | 21 +++++++++++++++++++++
2 files changed, 39 insertions(+)
diff --git a/lib/librte_eal/common/include/rte_common.h
b/lib/librte_eal/common/include/rte_common.h
index d102f2cec..7b50b8479 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -547,6 +547,24 @@ rte_bsf64_safe(uint64_t v, uint32_t *pos)
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);
+}
+
#ifndef offsetof
/** Return the offset of a field in a structure. */
#define offsetof(TYPE, MEMBER) __builtin_offsetof (TYPE, MEMBER)
diff --git a/test/test/test_common.c b/test/test/test_common.c
index 4a42aaed8..f6dd4c18d 100644
--- a/test/test/test_common.c
+++ b/test/test/test_common.c
@@ -242,6 +242,8 @@ test_fls(void)
};
for (i = 0; i < RTE_DIM(test); i++) {
+ uint64_t arg64;
+
arg = test[i].arg;
rc = rte_fls_u32(arg);
expected = test[i].rc;
@@ -250,6 +252,25 @@ test_fls(void)
arg, rc, expected);
return TEST_FAILED;
}
+ /* 64-bit version */
+ arg = test[i].arg;
+ rc = rte_fls_u64(arg);
+ expected = test[i].rc;
+ if (rc != expected) {
+ printf("Wrong rte_fls_u64(0x%x) rc=%d, expected=%d\n",
+ arg, rc, expected);
+ return TEST_FAILED;
+ }
+ /* 64-bit version shifted by 32 bits */
+ arg64 = (uint64_t)test[i].arg << 32;
+ rc = rte_fls_u64(arg64);
+ /* don't shift zero */
+ expected = test[i].rc == 0 ? 0 : test[i].rc + 32;
+ if (rc != expected) {
+ printf("Wrong rte_fls_u64(0x%" PRIx64 ") rc=%d,
expected=%d\n",
+ arg64, rc, expected);
+ return TEST_FAILED;
+ }
}
return 0;
--
2.17.1
