linux-kernel - [patch V4 12/31] lib: bch: use parity32

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Message-Id: <1462958308-25088-1-git-send-email-zengzhaoxiu@163.com>
Date:	Wed, 11 May 2016 17:18:26 +0800
From:	zengzhaoxiu@....com
To:	linux-kernel@...r.kernel.org, akpm@...ux-foundation.org
Cc:	Zhaoxiu Zeng <zhaoxiu.zeng@...il.com>
Subject: [patch V4 12/31] lib: bch: use parity32

From: Zhaoxiu Zeng <zhaoxiu.zeng@...il.com>

Signed-off-by: Zhaoxiu Zeng <zhaoxiu.zeng@...il.com>
---
 lib/bch.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/lib/bch.c b/lib/bch.c
index bc89dfe4..6c6e8d4 100644
--- a/lib/bch.c
+++ b/lib/bch.c
@@ -278,18 +278,6 @@ static inline int deg(unsigned int poly)
 	return fls(poly)-1;
 }
 
-static inline int parity(unsigned int x)
-{
-	/*
-	 * public domain code snippet, lifted from
-	 * http://www-graphics.stanford.edu/~seander/bithacks.html
-	 */
-	x ^= x >> 1;
-	x ^= x >> 2;
-	x = (x & 0x11111111U) * 0x11111111U;
-	return (x >> 28) & 1;
-}
-
 /* Galois field basic operations: multiply, divide, inverse, etc. */
 
 static inline unsigned int gf_mul(struct bch_control *bch, unsigned int a,
@@ -494,7 +482,7 @@ static int solve_linear_system(struct bch_control *bch, unsigned int *rows,
 		tmp = 0;
 		for (r = m-1; r >= 0; r--) {
 			mask = rows[r] & (tmp|1);
-			tmp |= parity(mask) << (m-r);
+			tmp |= parity32(mask) << (m-r);
 		}
 		sol[p] = tmp >> 1;
 	}
-- 
2.7.4