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From: Yerden Zhumabekov <e_zhumabekov@sts.kz>
To: <dev@dpdk.org>
Subject: [dpdk-dev] [PATCH v2] hash: fix breaking strict-aliasing rules
Date: Tue, 24 Mar 2015 19:31:55 +0600	[thread overview]
Message-ID: <3ba2a35fc1c2e9e3058d678908e2245d88bd7743.1427203852.git.e_zhumabekov@sts.kz> (raw)
In-Reply-To: <b441d020bd7830b1c66b6f4d2aa8d776a7f0bffd.1426697208.git.e_zhumabekov@sts.kz>

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(-)

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:
-- 
1.7.9.5

  parent reply	other threads:[~2015-03-24 13:30 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-18 16:51 [dpdk-dev] [PATCH] " Yerden Zhumabekov
2015-03-19 16:25 ` Bruce Richardson
2015-03-19 16:31   ` Bruce Richardson
2015-03-20  3:29     ` Yerden Zhumabekov
2015-03-20 12:41 ` Pawel Wodkowski
2015-03-20 12:47 ` Pawel Wodkowski
2015-03-21  6:57   ` Жумабеков Ерден Мирзагулович
2015-03-24 13:31 ` Yerden Zhumabekov [this message]
2015-03-26 17:47   ` [dpdk-dev] [PATCH v2] " De Lara Guarch, Pablo
2015-03-27  9:26     ` Thomas Monjalon

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