Re: IMA vs tree-ssa

[Dale Johannesen <dalej at apple dot com>]

On Feb 27, 2004, at 10:35 AM, Dale Johannesen wrote:
> On Feb 26, 2004, at 5:02 PM, Dale Johannesen wrote:
> > On Feb 26, 2004, at 4:21 PM, law@redhat.com wrote:
> > > In message <47CEA8A4-68B9-11D8-8C0E-000A95D7CD40@apple.com>, Dale 
> > > Johannesen wr
> > > ites:
> > > > Perhaps maybe_fold_offset_to_array_ref ought to ignore the type
> > > > "mismatch",
> > > > at least when offset is 0.    I can't see that *&x (for x an array)
> > > > should ever be anything but x[0].  Let me try that...
> > > My only concern would be that you might get a bad operand type 
> > > mis-match;
> > > though for this code I don't really see how that could happen.
> >
> > This gets farther than before in 176.gcc; there's an apparently 
> > unrelated BE crash later.
> > As you're OK with the idea, I'll bootstrap/test this overnight.
>
> Bootstrap and test passed but given rth's comments I'll look at a 
> langhook for
> comptypes  instead of submitting this.

This bit seems to be working, but doesn't solve the entire problem by 
any means.
The tree-based aliasing and structure-scalarizing code also think 
there's only
one copy of a struct type node, and work off pointers.   There may be 
more places
I haven't found yet; can you think of any?  (Most of the SPEC failures 
seem to be
due to aliasing; it thinks different copies of a struct from different 
files do not
alias, when in fact they do.  This breaks lots of things.)