From: Anatoly Burakov <anatoly.burakov@intel.com>
To: dev@dpdk.org
Cc: thomas@monjalon.net, jasvinder.singh@intel.com,
cristian.dumitrescu@intel.com, jerin.jacob@caviumnetworks.com
Subject: [dpdk-dev] [PATCH 3/6] common: add missing implementations
Date: Tue, 11 Dec 2018 17:57:11 +0000 [thread overview]
Message-ID: <e45a0cd3276537ce1d52b937bd2d08db9c4a348e.1544550999.git.anatoly.burakov@intel.com> (raw)
In-Reply-To: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com>
In-Reply-To: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com>
Implement missing functions for 32-bit safe bsf, as well as 64-bit
fls and log2.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
Notes:
v4:
- Fixed to use proper rte_bsf64
v3:
- Added clarification that pos is not checked
lib/librte_eal/common/include/rte_common.h | 62 +++++++++++++++++++++-
1 file changed, 61 insertions(+), 1 deletion(-)
diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h
index 2735dcca7..4bbfef7a0 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -447,6 +447,30 @@ rte_bsf32(uint32_t v)
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.
*
@@ -464,7 +488,6 @@ rte_log2_u32(uint32_t v)
return rte_bsf32(v);
}
-
/**
* Return the last (most-significant) bit set.
*
@@ -523,6 +546,43 @@ 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);
+}
+
+/**
+ * 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)
--
2.17.1
next prev parent reply other threads:[~2018-12-11 17:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 17:57 [dpdk-dev] [PATCH 1/6] bitmap: remove deprecated bsf64 function Anatoly Burakov
2018-12-11 17:57 ` [dpdk-dev] [PATCH 2/6] common: add bsf64 function similar to existing bsf32 Anatoly Burakov
2018-12-20 9:08 ` Thomas Monjalon
2018-12-11 17:57 ` Anatoly Burakov [this message]
2018-12-20 9:09 ` [dpdk-dev] [PATCH 3/6] common: add missing implementations Thomas Monjalon
2018-12-20 9:16 ` Burakov, Anatoly
2018-12-11 17:57 ` [dpdk-dev] [PATCH 4/6] memalloc: use library implementation of 64-bit log2 Anatoly Burakov
2018-12-11 17:57 ` [dpdk-dev] [PATCH 5/6] testpmd: " Anatoly Burakov
2018-12-12 11:22 ` Iremonger, Bernard
2018-12-11 17:57 ` [dpdk-dev] [PATCH 6/6] test/common: extend autotest to newly added functions Anatoly Burakov
2018-12-20 12:07 ` [dpdk-dev] [PATCH v2] common: add 64-bit log2 function Anatoly Burakov
2018-12-20 12:10 ` Burakov, Anatoly
2018-12-20 12:09 ` [dpdk-dev] [PATCH v2 1/4] bitmap: remove deprecated bsf64 function Anatoly Burakov
2018-12-20 23:44 ` Thomas Monjalon
2018-12-20 12:09 ` [dpdk-dev] [PATCH v2 2/4] common: add bsf64 and bsf32_safe functions Anatoly Burakov
2018-12-20 12:09 ` [dpdk-dev] [PATCH v2 3/4] common: add 64-bit fls function Anatoly Burakov
2018-12-20 12:09 ` [dpdk-dev] [PATCH v2 4/4] common: add 64-bit log2 function Anatoly Burakov
2018-12-20 22:37 ` Thomas Monjalon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e45a0cd3276537ce1d52b937bd2d08db9c4a348e.1544550999.git.anatoly.burakov@intel.com \
--to=anatoly.burakov@intel.com \
--cc=cristian.dumitrescu@intel.com \
--cc=dev@dpdk.org \
--cc=jasvinder.singh@intel.com \
--cc=jerin.jacob@caviumnetworks.com \
--cc=thomas@monjalon.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).