X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-arm%2Fbyteorder.h;h=17eaf8bdf0925a7b0146df2d6e35f8ac08cf3484;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=d648a1915c334e5ef0001d6c479e917895aae09d;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/include/asm-arm/byteorder.h b/include/asm-arm/byteorder.h
index d648a1915..17eaf8bdf 100644
--- a/include/asm-arm/byteorder.h
+++ b/include/asm-arm/byteorder.h
@@ -15,9 +15,32 @@
 #ifndef __ASM_ARM_BYTEORDER_H
 #define __ASM_ARM_BYTEORDER_H
 
-
+#include <linux/compiler.h>
 #include <asm/types.h>
 
+static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
+{
+	__u32 t;
+
+	if (__builtin_constant_p(x)) {
+		t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
+	} else {
+		/*
+		 * The compiler needs a bit of a hint here to always do the
+		 * right thing and not screw it up to different degrees
+		 * depending on the gcc version.
+		 */
+		asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
+	}
+	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__