It would be nice if (IWBNI), the compiler could recognize that the code below doesn't require a
temporary, since p can reside in DPTR the whole time. I guess this requires moving more of the
responsibility of optimization from the low level (peephole) to a higher lever (global).
void f( xdata char *p )
*p = 1;
*++p = 2;
*++p = 3;
*++p = 4;