Missed optimization in m68k

[Peter Barada]

I'm compiling the small snippet:

char *copy(const char *src, char *dst)
{
  char *dst0 = dst;
  while (*dst++ = *src++)
    ;
  return dst0;
}

And when compiled with 3.0.4 I get:

copy:
	move.l 4(%sp),%a1
	move.l 8(%sp),%a0
	move.l %a0,%d0
.L2:
	move.b (%a1)+,(%a0)
	tst.b (%a0)+
	jbne .L2
	rts


The problem is that the tst.b is not necessary since the move.b
updated the condition codes as part of the move.  How can I best
convince gcc that it should generate the follwing instead:

copy:
	move.l 4(%sp),%a1
	move.l 8(%sp),%a0
	move.l %a0,%d0
.L2:
	move.b (%a1)+,(%a0)+
	jbne .L2
	rts

Thanx...

-- 
Peter Barada                                   Peter.Barada@motorola.com
Wizard                                         781-852-2768 (direct)
WaveMark Solutions(wholly owned by Motorola)   781-270-0193 (fax)