net: rte_ether minor optimizations
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Commit Message
* rte_is_broadcast_ether_addr():
Use binary logic instead of comparisons and boolean logic, thus reducing
the number of branches.
It now resembles rte_is_zero_ether_addr().
* rte_ether_addr_copy():
The source code modifications were discussed on the mailing list:
http://mails.dpdk.org/archives/dev/2020-June/171584.html
Remove obsolete ICC-specific code and related comment.
Restrict pointer aliasing (suggested by Jerin Jacob).
Remove superfluous "Fast" from function description headline; all DPDK
data plane functions are supposed to be fast.
Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
---
lib/librte_net/rte_ether.h | 24 ++++++------------------
1 file changed, 6 insertions(+), 18 deletions(-)
Comments
On Fri, Jun 26, 2020 at 06:51:35PM +0200, Morten Brørup wrote:
> * rte_is_broadcast_ether_addr():
> Use binary logic instead of comparisons and boolean logic, thus reducing
> the number of branches.
> It now resembles rte_is_zero_ether_addr().
>
> * rte_ether_addr_copy():
> The source code modifications were discussed on the mailing list:
> http://mails.dpdk.org/archives/dev/2020-June/171584.html
> Remove obsolete ICC-specific code and related comment.
> Restrict pointer aliasing (suggested by Jerin Jacob).
> Remove superfluous "Fast" from function description headline; all DPDK
> data plane functions are supposed to be fast.
>
> Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
On 7/27/2020 8:34 AM, Olivier Matz wrote:
> On Fri, Jun 26, 2020 at 06:51:35PM +0200, Morten Brørup wrote:
>> * rte_is_broadcast_ether_addr():
>> Use binary logic instead of comparisons and boolean logic, thus reducing
>> the number of branches.
>> It now resembles rte_is_zero_ether_addr().
>>
>> * rte_ether_addr_copy():
>> The source code modifications were discussed on the mailing list:
>> http://mails.dpdk.org/archives/dev/2020-June/171584.html
>> Remove obsolete ICC-specific code and related comment.
>> Restrict pointer aliasing (suggested by Jerin Jacob).
>> Remove superfluous "Fast" from function description headline; all DPDK
>> data plane functions are supposed to be fast.
>>
>> Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
>
> Acked-by: Olivier Matz <olivier.matz@6wind.com>
>
Applied to dpdk-next-net/main, thanks.
@@ -146,10 +146,9 @@ static inline int rte_is_multicast_ether_addr(const struct rte_ether_addr *ea)
*/
static inline int rte_is_broadcast_ether_addr(const struct rte_ether_addr *ea)
{
- const uint16_t *ea_words = (const uint16_t *)ea;
+ const uint16_t *w = (const uint16_t *)ea;
- return (ea_words[0] == 0xFFFF && ea_words[1] == 0xFFFF &&
- ea_words[2] == 0xFFFF);
+ return (w[0] & w[1] & w[2]) == 0xFFFF;
}
/**
@@ -208,29 +207,18 @@ void
rte_eth_random_addr(uint8_t *addr);
/**
- * Fast copy an Ethernet address.
+ * Copy an Ethernet address.
*
* @param ea_from
* A pointer to a ether_addr structure holding the Ethernet address to copy.
* @param ea_to
* A pointer to a ether_addr structure where to copy the Ethernet address.
*/
-static inline void rte_ether_addr_copy(const struct rte_ether_addr *ea_from,
- struct rte_ether_addr *ea_to)
+static inline void
+rte_ether_addr_copy(const struct rte_ether_addr *__restrict ea_from,
+ struct rte_ether_addr *__restrict ea_to)
{
-#ifdef __INTEL_COMPILER
- uint16_t *from_words = (uint16_t *)(ea_from->addr_bytes);
- uint16_t *to_words = (uint16_t *)(ea_to->addr_bytes);
-
- to_words[0] = from_words[0];
- to_words[1] = from_words[1];
- to_words[2] = from_words[2];
-#else
- /*
- * Use the common way, because of a strange gcc warning.
- */
*ea_to = *ea_from;
-#endif
}
#define RTE_ETHER_ADDR_FMT_SIZE 18