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authorAndre McCurdy <armcc2000@yahoo.com>2006-01-07 11:39:20 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-01-07 11:39:20 +0000
commit6351610d6906aacbf9176cbdd045dd3876eec4c0 (patch)
treeaf6219c7a958f91c4d62fd1622954ed91ed1a9e7
parent2c041f4b9be5cecbd0a042ecd9122a9db6f50416 (diff)
[ARM] 3239/1: Add ARM optimised swab32
Patch from Andre McCurdy Replaces generic swab32 routine with a more ARM friendly version. Reduces kernel text size by approx 1200 bytes when compiled with 3.4.4 and approx 2400 bytes with 4.0.2 Probably some performance benefit as well. Signed-off-by: Andre McCurdy <armccurdy@yahoo.co.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--include/asm-arm/byteorder.h15
1 files changed, 14 insertions, 1 deletions
diff --git a/include/asm-arm/byteorder.h b/include/asm-arm/byteorder.h
index d648a1915c3..af42f449b9a 100644
--- a/include/asm-arm/byteorder.h
+++ b/include/asm-arm/byteorder.h
@@ -15,9 +15,22 @@
#ifndef __ASM_ARM_BYTEORDER_H
#define __ASM_ARM_BYTEORDER_H
-
#include <asm/types.h>
+static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
+{
+ __u32 t;
+
+ t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
+ x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
+ t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
+ x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
+
+ return x;
+}
+
+#define __arch__swab32(x) ___arch__swab32(x)
+
#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
# define __BYTEORDER_HAS_U64__
# define __SWAB_64_THRU_32__