[dpdk-dev] [PATCH 3/3] net: run-time function selection

[Elza Mathew]

Compile-time function selection can potentially lead to
lower performance on generic builds done by distros.
Replaced compile time flag checks with run-time
function selection.

Signed-off-by: Elza Mathew <elza.mat...@intel.com>
---
 lib/librte_net/rte_net_crc.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/librte_net/rte_net_crc.c b/lib/librte_net/rte_net_crc.c
index 661fe32..8f6a0e7 100644
--- a/lib/librte_net/rte_net_crc.c
+++ b/lib/librte_net/rte_net_crc.c
@@ -39,8 +39,8 @@
 #include <rte_common.h>
 #include <rte_net_crc.h>
 
-#if defined(RTE_ARCH_X86_64) && defined(RTE_MACHINE_CPUFLAG_PCLMULQDQ)
-#define X86_64_SSE42_PCLMULQDQ     1
+#ifdef RTE_ARCH_X86_64
+#include <net_crc_sse.h>
 #elif defined(RTE_ARCH_ARM64) && defined(RTE_MACHINE_CPUFLAG_PMULL)
 #define ARM64_NEON_PMULL           1
 #endif
@@ -71,7 +71,7 @@
        [RTE_NET_CRC32_ETH] = rte_crc32_eth_handler,
 };
 
-#ifdef X86_64_SSE42_PCLMULQDQ
+#ifdef RTE_ARCH_X86_64
 static rte_net_crc_handler handlers_sse42[] = {
        [RTE_NET_CRC16_CCITT] = rte_crc16_ccitt_sse42_handler,
        [RTE_NET_CRC32_ETH] = rte_crc32_eth_sse42_handler,
@@ -169,10 +169,12 @@
 rte_net_crc_set_alg(enum rte_net_crc_alg alg)
 {
        switch (alg) {
-#ifdef X86_64_SSE42_PCLMULQDQ
+#ifdef RTE_ARCH_X86_64
        case RTE_NET_CRC_SSE42:
-               handlers = handlers_sse42;
-               break;
+               if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_PCLMULQDQ)) {
+                       handlers = handlers_sse42;
+                       break;
+               }
 #elif defined ARM64_NEON_PMULL
                /* fall-through */
        case RTE_NET_CRC_NEON:
@@ -212,9 +214,11 @@ static inline void __attribute__((constructor))
 
        rte_net_crc_scalar_init();
 
-#ifdef X86_64_SSE42_PCLMULQDQ
-       alg = RTE_NET_CRC_SSE42;
-       rte_net_crc_sse42_init();
+#ifdef RTE_ARCH_X86_64
+       if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_PCLMULQDQ)) {
+               alg = RTE_NET_CRC_SSE42;
+               rte_net_crc_sse42_init();
+       }
 #elif defined ARM64_NEON_PMULL
        if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_PMULL)) {
                alg = RTE_NET_CRC_NEON;
-- 
1.9.1