[dpdk-dev] [PATCH v2] net: fix build with gcc 4.4.7 and strict aliasing

[Daniel Mrzyglod <danielx.t.mrzyglod@intel.com>]

This fix is for IPv6 checksum offload error on RHEL65.
Any optimalisation above -O0 provide error in IPv6 checksum
flag "-fstrict-aliasing" is default for optimalisation above -O0.

Fixes: 2b039d5f20a3 ("net: fix build with gcc 4.4.7 and strict aliasing")

Signed-off-by: Daniel Mrzyglod <danielx.t.mrzyglod@intel.com>
---
 lib/librte_net/rte_ip.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
index 71c519a..5b7554a 100644
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -169,7 +169,8 @@ __rte_raw_cksum(const void *buf, size_t len, uint32_t sum)
 {
 	/* workaround gcc strict-aliasing warning */
 	uintptr_t ptr = (uintptr_t)buf;
-	const uint16_t *u16 = (const uint16_t *)ptr;
+	typedef uint16_t __attribute__((__may_alias__)) u16_p;
+	const u16_p *u16 = (const u16_p *)ptr;
 
 	while (len >= (sizeof(*u16) * 4)) {
 		sum += u16[0];
-- 
2.5.0