6729208 Optimize BSWAP_* and BE_* macros in sys/byteorder.h to use inline amd64 assembly

*** 98,111 ****
  
  /*
   * Macros to reverse byte order
   */
  #define BSWAP_8(x)      ((x) & 0xff)
  #define BSWAP_16(x)     ((BSWAP_8(x) << 8) | BSWAP_8((x) >> 8))
! #define BSWAP_32(x)     ((BSWAP_16(x) << 16) | BSWAP_16((x) >> 16))
! #define BSWAP_64(x)     ((BSWAP_32(x) << 32) | BSWAP_32((x) >> 32))
  
  #define BMASK_8(x)      ((x) & 0xff)
  #define BMASK_16(x)     ((x) & 0xffff)
  #define BMASK_32(x)     ((x) & 0xffffffff)
  #define BMASK_64(x)     (x)
  
--- 98,132 ----
  
  /*
   * Macros to reverse byte order
   */
  #define BSWAP_8(x)      ((x) & 0xff)
+ #if !defined(__i386) && !defined(__amd64)
  #define BSWAP_16(x)     ((BSWAP_8(x) << 8) | BSWAP_8((x) >> 8))
! #define BSWAP_32(x)     (((uint32_t)(x) << 24) | \
!                         (((uint32_t)(x) << 8) & 0xff0000) | \
!                         (((uint32_t)(x) >> 8) & 0xff00) | \
!                         ((uint32_t)(x)  >> 24))
! #else /* x86 */
! #define BSWAP_16(x)     htons(x)
! #define BSWAP_32(x)     htonl(x)
! #endif  /* !__i386 && !__amd64 */
  
+ #if (!defined(__i386) && !defined(__amd64)) || \
+         ((defined(_XPG4_2) || defined(_XPG5)) && !defined(__EXTENSIONS__))
+ #define BSWAP_64(x)     (((uint64_t)(x) << 56) | \
+                         (((uint64_t)(x) << 40) & 0xff000000000000ULL) | \
+                         (((uint64_t)(x) << 24) & 0xff0000000000ULL) | \
+                         (((uint64_t)(x) << 8)  & 0xff00000000ULL) | \
+                         (((uint64_t)(x) >> 8)  & 0xff000000ULL) | \
+                         (((uint64_t)(x) >> 24) & 0xff0000ULL) | \
+                         (((uint64_t)(x) >> 40) & 0xff00ULL) | \
+                         ((uint64_t)(x)  >> 56))
+ #else /* x86 with non-XPG extensions allowed */
+ #define BSWAP_64(x)     htonll(x)
+ #endif  /* (!__i386&&!__amd64) || ((_XPG4_2||_XPG5) && !__EXTENSIONS__) */
+ 
  #define BMASK_8(x)      ((x) & 0xff)
  #define BMASK_16(x)     ((x) & 0xffff)
  #define BMASK_32(x)     ((x) & 0xffffffff)
  #define BMASK_64(x)     (x)
  
*** 138,155 ****
   */
  
  #define BE_IN8(xa) \
          *((uint8_t *)(xa))
  
  #define BE_IN16(xa) \
!         (((uint16_t)BE_IN8(xa) << 8) | BE_IN8((uint8_t *)(xa)+1))
  
  #define BE_IN32(xa) \
!         (((uint32_t)BE_IN16(xa) << 16) | BE_IN16((uint8_t *)(xa)+2))
  
  #define BE_IN64(xa) \
!         (((uint64_t)BE_IN32(xa) << 32) | BE_IN32((uint8_t *)(xa)+4))
  
  #define LE_IN8(xa) \
          *((uint8_t *)(xa))
  
  #define LE_IN16(xa) \
--- 159,187 ----
   */
  
  #define BE_IN8(xa) \
          *((uint8_t *)(xa))
  
+ #if !defined(__i386) && !defined(__amd64)
  #define BE_IN16(xa) \
!         (((uint16_t)BE_IN8(xa) << 8) | BE_IN8((uint8_t *)(xa) + 1))
  
  #define BE_IN32(xa) \
!         (((uint32_t)BE_IN16(xa) << 16) | BE_IN16((uint8_t *)(xa) + 2))
  
+ #else /* x86 */
+ #define BE_IN16(xa) htons(*((uint16_t *)(void *)(xa)))
+ #define BE_IN32(xa) htonl(*((uint32_t *)(void *)(xa)))
+ #endif  /* !__i386 && !__amd64 */
+ 
+ #if (!defined(__i386) && !defined(__amd64)) || \
+         ((defined(_XPG4_2) || defined(_XPG5)) && !defined(__EXTENSIONS__))
  #define BE_IN64(xa) \
!         (((uint64_t)BE_IN32(xa) << 32) | BE_IN32((uint8_t *)(xa) + 4))
! #else /* x86 with non-XPG extensions allowed */
! #define BE_IN64(xa) htonll(*((uint64_t *)(void *)(xa)))
! #endif  /* (!__i386&&!__amd64) || ((_XPG4_2||_XPG5) && !__EXTENSIONS__) */
  
  #define LE_IN8(xa) \
          *((uint8_t *)(xa))
  
  #define LE_IN16(xa) \
*** 174,186 ****
--- 206,223 ----
  
  #define BE_OUT32(xa, yv) \
          BE_OUT16((uint8_t *)(xa) + 2, yv); \
          BE_OUT16((uint8_t *)(xa), (yv) >> 16);
  
+ #if (!defined(__i386) && !defined(__amd64)) || \
+         ((defined(_XPG4_2) || defined(_XPG5)) && !defined(__EXTENSIONS__))
  #define BE_OUT64(xa, yv) \
          BE_OUT32((uint8_t *)(xa) + 4, yv); \
          BE_OUT32((uint8_t *)(xa), (yv) >> 32);
+ #else /* x86 with non-XPG extensions allowed */
+ #define BE_OUT64(xa, yv) *((uint64_t *)(void *)(xa)) = htonll((uint64_t)(yv));
+ #endif  /* (!__i386&&!__amd64) || ((_XPG4_2||_XPG5) && !__EXTENSIONS__) */
  
  #define LE_OUT8(xa, yv) *((uint8_t *)(xa)) = (uint8_t)(yv);
  
  #define LE_OUT16(xa, yv) \
          LE_OUT8((uint8_t *)(xa), yv); \