svn commit: r216122 - head/sys/powerpc/include

[Nathan Whitehorn]

Author: nwhitehorn
Date: Thu Dec  2 15:10:27 2010
New Revision: 216122
URL: http://svn.freebsd.org/changeset/base/216122

Log:
  Define bswap macros for constants to allow the compiler to pre-compute
  byte-swapped versions of compile-time constants. This allows use of
  bswap() and htole*() in initializers, which is required to cross-build
  btxld.
  
  Obtained from:	sparc64

Modified:
  head/sys/powerpc/include/endian.h

Modified: head/sys/powerpc/include/endian.h
==============================================================================
--- head/sys/powerpc/include/endian.h	Thu Dec  2 13:40:21 2010	(r216121)
+++ head/sys/powerpc/include/endian.h	Thu Dec  2 15:10:27 2010	(r216122)
@@ -27,7 +27,6 @@
  * SUCH DAMAGE.
  *
  *	@(#)endian.h	8.1 (Berkeley) 6/10/93
- *	$NetBSD: endian.h,v 1.7 1999/08/21 05:53:51 simonb Exp $
  * $FreeBSD$
  */
 
@@ -79,17 +78,36 @@
 #define	BYTE_ORDER	_BYTE_ORDER
 #endif
 
-#ifdef __CC_SUPPORTS___INLINE
+#if defined(__GNUCLIKE_BUILTIN_CONSTANT_P)
+#define	__is_constant(x)	__builtin_constant_p(x)
+#else
+#define	__is_constant(x)	0
+#endif
+
+#define	__bswap16_const(x)	((((__uint16_t)(x) >> 8) & 0xff) |	\
+	(((__uint16_t)(x) << 8) & 0xff00))
+#define	__bswap32_const(x)	((((__uint32_t)(x) >> 24) & 0xff) |	\
+	(((__uint32_t)(x) >> 8) & 0xff00) |				\
+	(((__uint32_t)(x)<< 8) & 0xff0000) |				\
+	(((__uint32_t)(x) << 24) & 0xff000000))
+#define	__bswap64_const(x)	((((__uint64_t)(x) >> 56) & 0xff) |	\
+	(((__uint64_t)(x) >> 40) & 0xff00) |				\
+	(((__uint64_t)(x) >> 24) & 0xff0000) |				\
+	(((__uint64_t)(x) >> 8) & 0xff000000) |				\
+	(((__uint64_t)(x) << 8) & ((__uint64_t)0xff << 32)) |		\
+	(((__uint64_t)(x) << 24) & ((__uint64_t)0xff << 40)) |		\
+	(((__uint64_t)(x) << 40) & ((__uint64_t)0xff << 48)) |		\
+	(((__uint64_t)(x) << 56) & ((__uint64_t)0xff << 56)))
 
 static __inline __uint16_t
-__bswap16(__uint16_t _x)
+__bswap16_var(__uint16_t _x)
 {
 
 	return ((_x >> 8) | ((_x << 8) & 0xff00));
 }
 
 static __inline __uint32_t
-__bswap32(__uint32_t _x)
+__bswap32_var(__uint32_t _x)
 {
 
 	return ((_x >> 24) | ((_x >> 8) & 0xff00) | ((_x << 8) & 0xff0000) |
@@ -97,7 +115,7 @@ __bswap32(__uint32_t _x)
 }
 
 static __inline __uint64_t
-__bswap64(__uint64_t _x)
+__bswap64_var(__uint64_t _x)
 {
 
 	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
@@ -106,20 +124,16 @@ __bswap64(__uint64_t _x)
 	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
 }
 
+#define	__bswap16(x)	(__is_constant(x) ? __bswap16_const(x) : \
+	__bswap16_var(x))
+#define	__bswap32(x)	(__is_constant(x) ? __bswap32_const(x) : \
+	__bswap32_var(x))
+#define	__bswap64(x)	(__is_constant(x) ? __bswap64_const(x) : \
+	__bswap64_var(x))
+
 #define	__htonl(x)	((__uint32_t)(x))
 #define	__htons(x)	((__uint16_t)(x))
 #define	__ntohl(x)	((__uint32_t)(x))
 #define	__ntohs(x)	((__uint16_t)(x))
 
-#else /* !__CC_SUPPORTS___INLINE */
-
-/*
- * No optimizations are available for this compiler.  Fall back to
- * non-optimized functions by defining the constant usually used to prevent
- * redefinition.
- */
-#define	_BYTEORDER_FUNC_DEFINED
-
-#endif /* __CC_SUPPORTS___INLINE */
-
 #endif /* !_MACHINE_ENDIAN_H_ */