Add optimized version of the bswap macroes for constants if __OPTIMIZED__ is

defined.

1 files changed, 30 insertions, 2 deletions

diff --git a/sys/arm/include/endian.h b/sys/arm/include/endian.h
index 56d5d868db36..135392acac21 100644
--- a/sys/arm/include/endian.h
+++ b/sys/arm/include/endian.h
@@ -70,7 +70,7 @@ __bswap64(__uint64_t _x)
 }
 
 static __inline __uint32_t
-__bswap32(__uint32_t v)
+__bswap32_var(__uint32_t v)
 {
 	__uint32_t t1;
 
@@ -83,7 +83,7 @@ __bswap32(__uint32_t v)
  }
 
 static __inline __uint16_t
-__bswap16(__uint32_t v)
+__bswap16_var(__uint32_t v)
 {
 	__asm __volatile(
 	    "mov    %0, %1, ror #8\n"
@@ -94,4 +94,32 @@ __bswap16(__uint32_t v)
 	
 	return (v);
 }		
+
+#ifdef __OPTIMIZE__
+
+#define __bswap32_constant(x)	\
+    ((((x) & 0xff000000U) >> 24) |	\
+     (((x) & 0x00ff0000U) >>  8) |	\
+     (((x) & 0x0000ff00U) <<  8) |	\
+     (((x) & 0x000000ffU) << 24))
+
+#define __bswap16_constant(x)	\
+    ((((x) & 0xff00) >> 8) |		\
+     (((x) & 0x00ff) << 8))
+
+#define __bswap16(x)	\
+    (__builtin_constant_p(x) ?	\
+     __bswap16_constant(x) : \
+     __bswap16_var(x))
+
+#define __bswap32(x)	\
+    (__builtin_constant_p(x) ? 	\
+     __bswap32_constant(x) : \
+     __bswap32_var(x))
+
+#else
+#define __bswap16(x)	__bswap16_var(x)
+#define __bswap32(x)	__bswap32_var(x)
+
+#endif /* __OPTIMIZE__ */
 #endif /* !_ENDIAN_H_ */