Hi Thomas, What's going on with this patch?
I really do not have other better solution. Thanks, Michael On 12/8/2014 9:30 AM, Qiu, Michael wrote: > On 12/4/2014 9:35 PM, Michael Qiu wrote: >> app/test-pmd/csumonly.c: In function ?get_psd_sum?: >> build/include/rte_ip.h:161: error: dereferencing pointer ?u16? >> does break strict-aliasing rules >> build/include/rte_ip.h:157: note: initialized from here >> ... >> >> The root cause is that, compile enable strict aliasing by default, >> while in function rte_raw_cksum() try to convert 'const char *' >> to 'const uint16_t *'. >> >> This patch is one workaround fix. >> >> Signed-off-by: Michael Qiu <michael.qiu at intel.com> >> --- >> v3 --> v2: >> use uintptr_t instead of unsigned long to >> save pointer. >> >> v2 --> v1: >> Workaround solution instead of shut off the >> gcc params. >> >> 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 61e4457..cda3436 100644 >> --- a/lib/librte_net/rte_ip.h >> +++ b/lib/librte_net/rte_ip.h >> @@ -154,7 +154,8 @@ struct ipv4_hdr { >> static inline uint16_t >> rte_raw_cksum(const char *buf, size_t len) >> { >> - const uint16_t *u16 = (const uint16_t *)buf; >> + uintptr_t ptr = (uintptr_t)buf; >> + const uint16_t *u16 = (const uint16_t *)ptr; >> uint32_t sum = 0; >> >> while (len >= (sizeof(*u16) * 4)) { > This workaround is to solve the compile issue of GCC strict-aliasing(Two > different type pointers should not be point to the same memory address). > > For GCC 4.4.7 it will definitely occurs if flags "-fstrict-aliasing" > and "-Wall" used. > > Thanks, > Michael >