From 6351610d6906aacbf9176cbdd045dd3876eec4c0 Mon Sep 17 00:00:00 2001 From: Andre McCurdy Date: Sat, 7 Jan 2006 11:39:20 +0000 Subject: [PATCH] [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 Signed-off-by: Russell King --- include/asm-arm/byteorder.h | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/include/asm-arm/byteorder.h b/include/asm-arm/byteorder.h index d648a1915c33..af42f449b9a6 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 +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__ -- 2.39.2