From: r k <rkerur@gmail.com>
To: "dev@dpdk.org" <dev@dpdk.org>
Subject: [dpdk-dev] [PATCH] Fix power_of_2 macro. Avoid branching when calculating RTE_MIN and RTE_MAX.
Date: Tue, 9 Dec 2014 13:05:22 -0800 [thread overview]
Message-ID: <CAFb4SLChYjhBGS4gnvfTGh-fqKTD7igFbwXdEypW7A=NMaQSdA@mail.gmail.com> (raw)
In-Reply-To: <EDD8E64855FBDA45ACDFE02112E795B70DC84A59B7@HQ1-EXCH03.corp.brocade.com>
Subject: [PATCH] Fix power_of_2 macro. Avoid branching when
calculating RTE_MIN and RTE_MAX.
---
lib/librte_eal/common/include/rte_common.h | 6 +++---
lib/librte_pmd_e1000/igb_pf.c | 4 ++--
lib/librte_pmd_ixgbe/ixgbe_pf.c | 4 ++--
3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/lib/librte_eal/common/include/rte_common.h
b/lib/librte_eal/common/include/rte_common.h
index 921b91f..21b17ad 100644
--- a/lib/librte_eal/common/include/rte_common.h
+++ b/lib/librte_eal/common/include/rte_common.h
@@ -203,7 +203,7 @@ extern int RTE_BUILD_BUG_ON_detected_error;
static inline int rte_is_power_of_2(uint32_t n) {
- return ((n-1) & n) == 0;
+ return n && !(n & (n - 1));
}
/**
@@ -259,7 +259,7 @@ rte_align64pow2(uint64_t v) #define RTE_MIN(a, b) ({ \
typeof (a) _a = (a); \
typeof (b) _b = (b); \
- _a < _b ? _a : _b; \
+ _b ^ ((_a ^ _b) & -(_a < _b)); \
})
/**
@@ -268,7 +268,7 @@ rte_align64pow2(uint64_t v) #define RTE_MAX(a, b) ({ \
typeof (a) _a = (a); \
typeof (b) _b = (b); \
- _a > _b ? _a : _b; \
+ _a ^ ((_a ^ _b) & -(_a < _b)); \
})
/*********** Other general functions / macros ********/ diff --git
a/lib/librte_pmd_e1000/igb_pf.c b/lib/librte_pmd_e1000/igb_pf.c index
bc3816a..546499c 100644
--- a/lib/librte_pmd_e1000/igb_pf.c
+++ b/lib/librte_pmd_e1000/igb_pf.c
@@ -321,11 +321,11 @@ igb_vf_set_mac_addr(struct rte_eth_dev *dev,
uint32_t vf, uint32_t *msgbuf) static int
igb_vf_set_multicast(struct rte_eth_dev *dev, __rte_unused uint32_t
vf, uint32_t *msgbuf) {
- int i;
+ int16_t i;
uint32_t vector_bit;
uint32_t vector_reg;
uint32_t mta_reg;
- int entries = (msgbuf[0] & E1000_VT_MSGINFO_MASK) >>
+ int32_t entries = (msgbuf[0] & E1000_VT_MSGINFO_MASK) >>
E1000_VT_MSGINFO_SHIFT;
uint16_t *hash_list = (uint16_t *)&msgbuf[1];
struct e1000_hw *hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
diff --git a/lib/librte_pmd_ixgbe/ixgbe_pf.c
b/lib/librte_pmd_ixgbe/ixgbe_pf.c index 51da1fd..426caf9 100644
--- a/lib/librte_pmd_ixgbe/ixgbe_pf.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_pf.c
@@ -390,7 +390,7 @@ ixgbe_vf_set_multicast(struct rte_eth_dev *dev,
__rte_unused uint32_t vf, uint32
struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
struct ixgbe_vf_info *vfinfo =
*(IXGBE_DEV_PRIVATE_TO_P_VFDATA(dev->data->dev_private));
- int nb_entries = (msgbuf[0] & IXGBE_VT_MSGINFO_MASK) >>
+ int32_t nb_entries = (msgbuf[0] & IXGBE_VT_MSGINFO_MASK) >>
IXGBE_VT_MSGINFO_SHIFT;
uint16_t *hash_list = (uint16_t *)&msgbuf[1];
uint32_t mta_idx;
@@ -399,7 +399,7 @@ ixgbe_vf_set_multicast(struct rte_eth_dev *dev,
__rte_unused uint32_t vf, uint32
const uint32_t IXGBE_MTA_BIT_SHIFT = 5;
const uint32_t IXGBE_MTA_BIT_MASK = (0x1 << IXGBE_MTA_BIT_SHIFT) - 1;
uint32_t reg_val;
- int i;
+ int16_t i;
/* only so many hash values supported */
nb_entries = RTE_MIN(nb_entries, IXGBE_MAX_VF_MC_ENTRIES);
--
1.9.1
next prev parent reply other threads:[~2014-12-09 21:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1418157854-7642-1-git-send-email-rkerur@gmail.com>
[not found] ` <EDD8E64855FBDA45ACDFE02112E795B70DC84A59B9@HQ1-EXCH03.corp.brocade.com>
2014-12-09 21:05 ` [dpdk-dev] [PATCH] Small fixes in rte_common.h r k
[not found] ` <1418157854-7642-2-git-send-email-rkerur@gmail.com>
[not found] ` <EDD8E64855FBDA45ACDFE02112E795B70DC84A59B7@HQ1-EXCH03.corp.brocade.com>
2014-12-09 21:05 ` r k [this message]
2014-12-10 12:58 ` [dpdk-dev] [PATCH] Fix power_of_2 macro. Avoid branching when calculating RTE_MIN and RTE_MAX Thomas Monjalon
2014-12-10 16:48 ` r k
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='CAFb4SLChYjhBGS4gnvfTGh-fqKTD7igFbwXdEypW7A=NMaQSdA@mail.gmail.com' \
--to=rkerur@gmail.com \
--cc=dev@dpdk.org \
/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).