Usermode/libc - Slightly smarter memcpy

diff --git a/Usermode/Libraries/libc.so_src/string.c b/Usermode/Libraries/libc.so_src/string.c
index ceafd99..a5becf8 100644 (file)
--- a/Usermode/Libraries/libc.so_src/string.c
+++ b/Usermode/Libraries/libc.so_src/string.c
@@ -217,12 +217,36 @@ EXPORT void *memset(void *dest, int val, size_t num)
  * \fn EXPORT void *memcpy(void *dest, const void *src, size_t count)
  * \brief Copy one memory area to another
  */
-EXPORT void *memcpy(void *dest, const void *src, size_t count)
+EXPORT void *memcpy(void *__dest, const void *__src, size_t count)
 {
-    char *sp = (char *)src;
-    char *dp = (char *)dest;
-    for(;count--;) *dp++ = *sp++;
-    return dest;
+       const int       wordmask = sizeof(void*)-1;
+       uintptr_t       src = (uintptr_t)__src;
+       uintptr_t       dst = (uintptr_t)__dest;
+
+       if( count < sizeof(void*)*2 || (dst & wordmask) != (src & wordmask) )
+       {
+               char    *dp = __dest;
+               const char      *sp = __src;
+               while(count--) *dp++ = *sp ++;
+       }
+       else
+       {
+               void    **dp, **sp;
+               for( ; count && (dst & wordmask) != 0; count -- )
+                       *(char*)dst++ = *(char*)src++;
+
+               dp = (void*)dst; sp = (void*)src;
+               while( count >= sizeof(void*) )
+               {
+                       *dp++ = *sp++;
+                       count -= sizeof(void*);
+               }
+               dst = (uintptr_t)dp; src = (uintptr_t)sp;
+               for( ; count; count -- )
+                       *(char*)dst++ = *(char*)src++;
+       }
+
+       return __dest;
 }
 
 /**