byteswap: unify common definitions

The majority of the byteswap functions are the same across all arches, so
setup a common header to provide definitions if they don't exist.  This
allows arches to override only the ones they actually want to implement
with inline assembly.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 21 insertions, 79 deletions

diff --git a/libc/sysdeps/linux/ia64/bits/byteswap.h b/libc/sysdeps/linux/ia64/bits/byteswap.h
index 6862aa0b6..346c82c04 100644
--- a/libc/sysdeps/linux/ia64/bits/byteswap.h
+++ b/libc/sysdeps/linux/ia64/bits/byteswap.h
@@ -17,94 +17,36 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
-#if !defined _BYTESWAP_H && !defined _NETINET_IN_H
-# error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
-#endif
-
-#ifndef _BITS_BYTESWAP_H
-#define _BITS_BYTESWAP_H 1
-
-/* Swap bytes in 16 bit value.  */
-#define __bswap_constant_16(x) \
-     ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))
+#ifndef _ASM_BITS_BYTESWAP_H
+#define _ASM_BITS_BYTESWAP_H 1
 
-#if defined __GNUC__ && __GNUC__ >= 2
-# define __bswap_16(x) \
+#define __bswap_non_constant_16(x) \
      (__extension__							      \
-      ({ register unsigned short int __v, __x = (x);			      \
-	 if (__builtin_constant_p (x))					      \
-	   __v = __bswap_constant_16 (__x);				      \
-	 else								      \
-	   __asm__ __volatile__ ("shl %0 = %1, 48 ;;"			      \
-				 "mux1 %0 = %0, @rev ;;"		      \
-				 : "=r" (__v)				      \
-				 : "r" ((unsigned short int) (__x)));	      \
+      ({ register unsigned short int __v;				      \
+	 __asm__ __volatile__ ("shl %0 = %1, 48 ;;"			      \
+				"mux1 %0 = %0, @rev ;;"			      \
+				: "=r" (__v)				      \
+				: "r" ((unsigned short int) (x)));	      \
 	 __v; }))
-#else
-/* This is better than nothing.  */
-static __inline unsigned short int
-__bswap_16 (unsigned short int __bsx)
-{
-  return __bswap_constant_16 (__bsx);
-}
-#endif
-
 
-/* Swap bytes in 32 bit value.  */
-#define __bswap_constant_32(x) \
-     ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |		      \
-      (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))
-
-#if defined __GNUC__ && __GNUC__ >= 2
-# define __bswap_32(x) \
+#define __bswap_non_constant_32(x) \
      (__extension__							      \
-      ({ register unsigned int __v, __x = (x);				      \
-	 if (__builtin_constant_p (x))					      \
-	   __v = __bswap_constant_32 (__x);				      \
-	 else								      \
-	   __asm__ __volatile__ ("shl %0 = %1, 32 ;;"			      \
-				 "mux1 %0 = %0, @rev ;;"		      \
-				 : "=r" (__v)				      \
-				 : "r" ((unsigned int) (__x)));		      \
+      ({ register unsigned int __v;					      \
+	 __asm__ __volatile__ ("shl %0 = %1, 32 ;;"			      \
+				"mux1 %0 = %0, @rev ;;"			      \
+				: "=r" (__v)				      \
+				: "r" ((unsigned int) (x)));		      \
 	 __v; }))
-#else
-static __inline unsigned int
-__bswap_32 (unsigned int __bsx)
-{
-  return __bswap_constant_32 (__bsx);
-}
-#endif
-
 
-/* Swap bytes in 64 bit value.  */
-#define __bswap_constant_64(x) \
-     ((((x) & 0xff00000000000000ul) >> 56)				      \
-      | (((x) & 0x00ff000000000000ul) >>  40)				      \
-      | (((x) & 0x0000ff0000000000ul) >> 24)				      \
-      | (((x) & 0x000000ff00000000ul) >> 8)				      \
-      | (((x) & 0x00000000ff000000ul) << 8)				      \
-      | (((x) & 0x0000000000ff0000ul) << 24)				      \
-      | (((x) & 0x000000000000ff00ul) << 40)				      \
-      | (((x) & 0x00000000000000fful) << 56))
-
-#if defined __GNUC__ && __GNUC__ >= 2
-# define __bswap_64(x) \
+#define __bswap_non_constant_64(x) \
      (__extension__							      \
-      ({ register unsigned long int __v, __x = (x);			      \
-	 if (__builtin_constant_p (x))					      \
-	   __v = __bswap_constant_64 (__x);				      \
-	 else								      \
-	   __asm__ __volatile__ ("mux1 %0 = %1, @rev ;;"		      \
-				 : "=r" (__v)				      \
-				 : "r" ((unsigned long int) (__x)));	      \
+      ({ register unsigned long int __v;				      \
+	 __asm__ __volatile__ ("mux1 %0 = %1, @rev ;;"			      \
+				: "=r" (__v)				      \
+				: "r" ((unsigned long int) (x)));	      \
          __v; }))
+#endif
 
-#else
-static __inline unsigned long int
-__bswap_64 (unsigned long int __bsx)
-{
-  return __bswap_constant_64 (__bsx);
-}
 #endif
 
-#endif /* _BITS_BYTESWAP_H */
+#include <bits/byteswap-common.h>