Multiple set insns reload problem.

[Joern Rennecke]

> int a;
> main()
> {
>   int *ptr=&a;
>   asm("":"=r"(ptr):"0"(&a));  /* Hide the constant address behind cse */
>   asm("movl $0,%0 ; movl $0,%1":"=m,r"(*ptr),"=,c"(ptr));

I think you invoke undefined behaviour here, because you are updating
ptr in the same insn as you use it as address in a separate upadte, and
there is no sequence point between the updates.