On Fri, Jul 7, 2017 at 12:11 AM, Luc Van Oostenryck
<luc.vanoostenryck@xxxxxxxxx> wrote:
>> And remove_usage() is deleting the very same list
>> from with in the loop. That is the bug.
>
> Strange. kill_use_list() is only iterated via insn->phi_list
> or insn->arguments, not p->user.
>
> But yes, something is surely messing with the lists here.
>
I figure it out. It is a false alarm on the checking side.
The condition I want to check can still cause a bug,
but this report is not one of those conditions.
It is cause by this code:
static int dead_insn(struct instruction *insn, pseudo_t *src1,
pseudo_t *src2, pseudo_t *src3)
{
struct pseudo_user *pu;
FOR_EACH_PTR(insn->target->users, pu) {
if (*pu->userp != VOID)
return 0;
} END_FOR_EACH_PTR(pu);
So the return terminate the execution flow before
reaching to the END_FOR_EACH_PTR(pu).
The ptr->active still think we are in the loop
But we are not.
It is a bug in the checking side. I still think this kind
of checking is useful, but need some special handle
of bail out of the ptr_list loop.
Very sorry about that.
Chris
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