Included patch #5920: Create define to override C-library memcpy. 2 Defines are created: MEMCPY() for normal memcpy, SMEMCPY() for situations where some compilers might inline the copy and save a function call. Also replaced all calls to memcpy() with calls to (S)MEMCPY().

src/include/lwip/opt.h

@@ -53,6 +53,18 @@
 #define NO_SYS                          0
 #endif
 
+/* override this if you have a faster implementation at hand than the one
+   included in your C library */
+#ifndef MEMCPY
+#define MEMCPY(dst,src,len)             memcpy(dst,src,len)
+#endif
+
+/* override this with care: some compilers (e.g. gcc) can inline a call to
+   memcpy() if the length is known at compile time and is small */
+#ifndef SMEMCPY
+#define SMEMCPY(dst,src,len)            memcpy(dst,src,len)
+#endif
+
 /* ---------- Memory options ---------- */
 #ifndef MEM_LIBC_MALLOC
 #define MEM_LIBC_MALLOC                 0