Re: [PATCH] Fix PR tree-opt/17529, ICE due to *&a not being folded to a[0]

[Andrew Pinski <pinskia@physics.uc.edu>]

On Oct 27, 2004, at 1:01 PM, Jeffrey A Law wrote:

> On Sat, 2004-10-23 at 21:08 -0400, Andrew Pinski wrote:
>> I think the subject says what causes the problem and the reason why
>> we don't fold *&a into a[0] is because fold does not handle it
>> but fold_stmt does.
> We might consider moving this logic into the fold one day, but I
> suspect that's more intrusive than we want to tackle right now.
>

> However, I don't think this will fix the other testcase in that
> PR:
>
> bar (const int *const x)
> {
>   int x1 = *x;
> }
> static const int y[1]={0};
> void
> foo (void)
> {
>   bar (y);
> }

The other test is already fixed by the fact we call fold_stmt on
MODIFY_EXPR already.  In fact the only two places in gimple
where INDIRECT_REF (at this point) can show up is ASM_EXPR
or a MODIFY_EXPR so all cases are already handled.

I tested the following the case where you might expect that the
INDIRECT_REF might show up not in either ASM_EXPR or a MODIFY_EXPR
but does not as we use a temporary variable to store the address:
struct t
{
   int i;
};
void f(const int*const);
bar (const struct t *const x)
{
   f(&x->i);
}
static const struct t y[1];
void
foo (void)
{
   bar (y);
}

Thanks,
Andrew Pinski