gcc/testsuite/gcc.dg/string-opt-1.c

   1 /* Ensure mempcpy is not "optimized" into memcpy followed by addition.  */
   2 /* { dg-do compile } */
   3 /* { dg-options "-O2" } */
   4
   5 void *
   6 fn (char *x, char *y, int z)
   7 {
   8   return __builtin_mempcpy (x, y, z);
   9 }
  10
  11 /* { dg-final { scan-assembler-not "memcpy" } } */