[ia32] use __builtin_memcpy compiler intrinsic for small memcpy's

diff --git a/include/asm-i386/string.h b/include/asm-i386/string.h
index 10b2f0f9cea874147599859d480363024418580c..3a90a9e142cd47c0de9d9aa7d8fa92b8538e7d53 100644 (file)
--- a/include/asm-i386/string.h
+++ b/include/asm-i386/string.h
@@ -214,49 +214,9 @@ return (to);
  */
 static inline void * __constant_memcpy(void * to, const void * from, size_t n)
 {
-       switch (n) {
-               case 0:
-                       return to;
-               case 1:
-                       *(unsigned char *)to = *(const unsigned char *)from;
-                       return to;
-               case 2:
-                       *(unsigned short *)to = *(const unsigned short *)from;
-                       return to;
-               case 3:
-                       *(unsigned short *)to = *(const unsigned short *)from;
-                       *(2+(unsigned char *)to) = *(2+(const unsigned char *)from);
-                       return to;
-               case 4:
-                       *(unsigned long *)to = *(const unsigned long *)from;
-                       return to;
-               case 6: /* for Ethernet addresses */
-                       *(unsigned long *)to = *(const unsigned long *)from;
-                       *(2+(unsigned short *)to) = *(2+(const unsigned short *)from);
-                       return to;
-               case 8:
-                       *(unsigned long *)to = *(const unsigned long *)from;
-                       *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
-                       return to;
-               case 12:
-                       *(unsigned long *)to = *(const unsigned long *)from;
-                       *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
-                       *(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
-                       return to;
-               case 16:
-                       *(unsigned long *)to = *(const unsigned long *)from;
-                       *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
-                       *(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
-                       *(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
-                       return to;
-               case 20:
-                       *(unsigned long *)to = *(const unsigned long *)from;
-                       *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
-                       *(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
-                       *(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
-                       *(4+(unsigned long *)to) = *(4+(const unsigned long *)from);
-                       return to;
-       }
+       if (n <= 128)
+               return __builtin_memcpy(to, from, n);
+
 #define COMMON(x) \
 __asm__ __volatile__( \
        "rep ; movsl" \