2002-08-11 Roland McGrath <roland@redhat.com>
authorroland <roland>
Mon, 12 Aug 2002 02:01:24 +0000 (02:01 +0000)
committerroland <roland>
Mon, 12 Aug 2002 02:01:24 +0000 (02:01 +0000)
* sysdeps/i386/bits/byteswap.h (__bswap_16, __bswap_32, __bswap_64):
Evaluate argument exactly once.  Remove __volatile__ from asm's.

sysdeps/i386/bits/byteswap.h

index d08a342..6812c61 100644 (file)
 #if defined __GNUC__ && __GNUC__ >= 2
 # define __bswap_16(x) \
      (__extension__                                                          \
-      ({ register unsigned short int __v;                                    \
-        if (__builtin_constant_p (x))                                        \
-          __v = __bswap_constant_16 (x);                                     \
+      ({ register unsigned short int __v, __x = (x);                         \
+        if (__builtin_constant_p (__x))                                      \
+          __v = __bswap_constant_16 (__x);                                   \
         else                                                                 \
-          __asm__ __volatile__ ("rorw $8, %w0"                               \
-                                : "=r" (__v)                                 \
-                                : "0" ((unsigned short int) (x))             \
-                                : "cc");                                     \
+          __asm__ ("rorw $8, %w0"                                            \
+                   : "=r" (__v)                                              \
+                   : "0" (__x)                                               \
+                   : "cc");                                                  \
         __v; }))
 #else
 /* This is better than nothing.  */
-# define __bswap_16(x) __bswap_constant_16 (x)
+# define __bswap_16(x) \
+     (__extension__                                                          \
+      ({ register unsigned short int __x = (x); __bswap_constant_16 (__x); }))
 #endif
 
 
 /* To swap the bytes in a word the i486 processors and up provide the
    `bswap' opcode.  On i386 we have to use three instructions.  */
 # if !defined __i486__ && !defined __pentium__ && !defined __pentiumpro__
-#  define __bswap_32(x) \
+#  define __bswap_32(x)                                                              \
      (__extension__                                                          \
-      ({ register unsigned int __v;                                          \
-        if (__builtin_constant_p (x))                                        \
-          __v = __bswap_constant_32 (x);                                     \
+      ({ register unsigned int __v, __x = (x);                               \
+        if (__builtin_constant_p (__x))                                      \
+          __v = __bswap_constant_32 (__x);                                   \
         else                                                                 \
-          __asm__ __volatile__ ("rorw $8, %w0;"                              \
-                                "rorl $16, %0;"                              \
-                                "rorw $8, %w0"                               \
-                                : "=r" (__v)                                 \
-                                : "0" ((unsigned int) (x))                   \
-                                : "cc");                                     \
+          __asm__ ("rorw $8, %w0;"                                           \
+                   "rorl $16, %0;"                                           \
+                   "rorw $8, %w0"                                            \
+                   : "=r" (__v)                                              \
+                   : "0" (__x)                                               \
+                   : "cc");                                                  \
         __v; }))
 # else
 #  define __bswap_32(x) \
      (__extension__                                                          \
-      ({ register unsigned int __v;                                          \
-        if (__builtin_constant_p (x))                                        \
-          __v = __bswap_constant_32 (x);                                     \
+      ({ register unsigned int __v, __x = (x);                               \
+        if (__builtin_constant_p (__x))                                      \
+          __v = __bswap_constant_32 (__x);                                   \
         else                                                                 \
-          __asm__ __volatile__ ("bswap %0"                                   \
-                                : "=r" (__v)                                 \
-                                : "0" ((unsigned int) (x)));                 \
+          __asm__ ("bswap %0" : "=r" (__v) : "0" (__x));                     \
         __v; }))
 # endif
 #else
-# define __bswap_32(x) __bswap_constant_32 (x)
+# define __bswap_16(x) \
+     (__extension__                                                          \
+      ({ register unsigned int __x = (x); __bswap_constant_32 (__x); }))
 #endif
 
 
      (__extension__                                                          \
       ({ union { __extension__ unsigned long long int __ll;                  \
                 unsigned long int __l[2]; } __w, __r;                        \
-         if (__builtin_constant_p (x))                                       \
-          __r.__ll = __bswap_constant_64 (x);                                \
+        __w.__ll = (x);                                                      \
+         if (__builtin_constant_p (__w.__ll))                                \
+          __r.__ll = __bswap_constant_64 (__w.__ll);                         \
         else                                                                 \
           {                                                                  \
-            __w.__ll = (x);                                                  \
             __r.__l[0] = __bswap_32 (__w.__l[1]);                            \
             __r.__l[1] = __bswap_32 (__w.__l[0]);                            \
           }                                                                  \