diff mbox

[dpdk-dev,v2] hash: fix breaking strict-aliasing rules

Message ID 3ba2a35fc1c2e9e3058d678908e2245d88bd7743.1427203852.git.e_zhumabekov@sts.kz (mailing list archive)
State Accepted, archived
Headers

Commit Message

Yerden Zhumabekov March 24, 2015, 1:31 p.m. UTC 
  Fix rte_hash_crc() function by making use of uintptr_t variable
to hold a pointer to data being hashed. In this way, casting uint64_t
pointer to uint32_t avoided.

Signed-off-by: Yerden Zhumabekov <e_zhumabekov@sts.kz>
---
 lib/librte_hash/rte_hash_crc.h |   21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

Comments

De Lara Guarch, Pablo March 26, 2015, 5:47 p.m. UTC | #1 
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Yerden
> Zhumabekov
> Sent: Tuesday, March 24, 2015 1:32 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v2] hash: fix breaking strict-aliasing rules
> 
> Fix rte_hash_crc() function by making use of uintptr_t variable
> to hold a pointer to data being hashed. In this way, casting uint64_t
> pointer to uint32_t avoided.
> 
> Signed-off-by: Yerden Zhumabekov <e_zhumabekov@sts.kz>

Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Thomas Monjalon March 27, 2015, 9:26 a.m. UTC | #2 
> > Fix rte_hash_crc() function by making use of uintptr_t variable
> > to hold a pointer to data being hashed. In this way, casting uint64_t
> > pointer to uint32_t avoided.
> > 
> > Signed-off-by: Yerden Zhumabekov <e_zhumabekov@sts.kz>
> 
> Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>

Applied, thanks
diff mbox

Patch

diff --git a/lib/librte_hash/rte_hash_crc.h b/lib/librte_hash/rte_hash_crc.h
index 1cd626c..abdbd9a 100644
--- a/lib/librte_hash/rte_hash_crc.h
+++ b/lib/librte_hash/rte_hash_crc.h
@@ -513,35 +513,36 @@  rte_hash_crc(const void *data, uint32_t data_len, uint32_t init_val)
 {
 	unsigned i;
 	uint64_t temp = 0;
-	const uint64_t *p64 = (const uint64_t *)data;
+	uintptr_t pd = (uintptr_t) data;
 
 	for (i = 0; i < data_len / 8; i++) {
-		init_val = rte_hash_crc_8byte(*p64++, init_val);
+		init_val = rte_hash_crc_8byte(*(const uint64_t *)pd, init_val);
+		pd += 8;
 	}
 
 	switch (7 - (data_len & 0x07)) {
 	case 0:
-		temp |= (uint64_t) *((const uint8_t *)p64 + 6) << 48;
+		temp |= (uint64_t) *((const uint8_t *)pd + 6) << 48;
 		/* Fallthrough */
 	case 1:
-		temp |= (uint64_t) *((const uint8_t *)p64 + 5) << 40;
+		temp |= (uint64_t) *((const uint8_t *)pd + 5) << 40;
 		/* Fallthrough */
 	case 2:
-		temp |= (uint64_t) *((const uint8_t *)p64 + 4) << 32;
-		temp |= *((const uint32_t *)p64);
+		temp |= (uint64_t) *((const uint8_t *)pd + 4) << 32;
+		temp |= *(const uint32_t *)pd;
 		init_val = rte_hash_crc_8byte(temp, init_val);
 		break;
 	case 3:
-		init_val = rte_hash_crc_4byte(*(const uint32_t *)p64, init_val);
+		init_val = rte_hash_crc_4byte(*(const uint32_t *)pd, init_val);
 		break;
 	case 4:
-		temp |= *((const uint8_t *)p64 + 2) << 16;
+		temp |= *((const uint8_t *)pd + 2) << 16;
 		/* Fallthrough */
 	case 5:
-		temp |= *((const uint8_t *)p64 + 1) << 8;
+		temp |= *((const uint8_t *)pd + 1) << 8;
 		/* Fallthrough */
 	case 6:
-		temp |= *((const uint8_t *)p64);
+		temp |= *(const uint8_t *)pd;
 		init_val = rte_hash_crc_4byte(temp, init_val);
 		/* Fallthrough */
 	default: