In the replacement text of the __bswapN_const() macros encapsulate the

argument in parentheses so these macros are safe to use and invocations
with an expression as the argument like __bswap32_const(42 << 23 | 13)
work as expected. Additionally, mask all the individually shifted bytes
as appropriate so the bytes which exceed the width of the respective
__bswapN_const() macro in invocations like __bswap16_const(0xdead600d)
are ignored like it's the case with the corresponding __bswapN_var()
function.

MFC after:	3 days

1 files changed, 12 insertions, 8 deletions

diff --git a/sys/sun4v/include/endian.h b/sys/sun4v/include/endian.h
index a643dd3..1744784 100644
--- a/sys/sun4v/include/endian.h
+++ b/sys/sun4v/include/endian.h
@@ -69,14 +69,18 @@
 #define	__is_constant(x)	0
 #endif
 
-#define	__bswap16_const(x)	((x >> 8) | ((x << 8) & 0xff00))
-#define	__bswap32_const(x)	((x >> 24) | ((x >> 8) & 0xff00) |	\
-	((x << 8) & 0xff0000) | ((x << 24) & 0xff000000))
-#define	__bswap64_const(x)	((x >> 56) | ((x >> 40) & 0xff00) |	\
-	((x >> 24) & 0xff0000) | ((x >> 8) & 0xff000000) |		\
-	((x << 8) & ((__uint64_t)0xff << 32)) |				\
-	((x << 24) & ((__uint64_t)0xff << 40)) |			\
-	((x << 40) & ((__uint64_t)0xff << 48)) | ((x << 56)))
+#define	__bswap16_const(x)	((((x) >> 8) & 0xff) |			\
+	(((x) << 8) & 0xff00))
+#define	__bswap32_const(x)	((((x) >> 24) & 0xff) |			\
+	(((x) >> 8) & 0xff00) | (((x) << 8) & 0xff0000) |		\
+	(((x) << 24) & 0xff000000))
+#define	__bswap64_const(x)	((((x) >> 56) & 0xff) |			\
+	(((x) >> 40) & 0xff00) | (((x) >> 24) & 0xff0000) |		\
+	(((x) >> 8) & 0xff000000) |					\
+	(((x) << 8) & ((__uint64_t)0xff << 32)) |			\
+	(((x) << 24) & ((__uint64_t)0xff << 40)) |			\
+	(((x) << 40) & ((__uint64_t)0xff << 48)) |			\
+	(((x) << 56) & ((__uint64_t)0xff << 56)))
 
 static __inline __uint16_t
 __bswap16_var(__uint16_t _x)