[PATCH] Avoid bugs like PR68273 to trigger

[Jakub Jelinek]

On Fri, Feb 19, 2016 at 01:42:20PM +0100, Richard Biener wrote:
> On Fri, 19 Feb 2016, Bernd Schmidt wrote:
> 
> > On 02/19/2016 09:36 AM, Richard Biener wrote:
> > > Yup, so we should make sure we don't (even not "out of nowhere").  See
> > > my attempts on adding some SSA verification for this (needs to be
> > > restricted to overaligned, then it doesn't trigger that often...).
> > > One issue is that we've often got DECLs that are overaligned but at
> > > some point re-write them into SSA - and the SSA verifier expects the
> > > SSA name types to agree with their decls type.
> > 
> > Sounds like the verifier needs to be relaxed a little?
> 
> No, we really use those two types interchangeably.  If it's
> a DECL_INGORED var adjusting it is fine I think, but if it's a
> user var we'd drop some debug info (do we actually emit alignment

I think we don't right now, but DWARF5 is going to have attributes for this,
so we'll start soon.

> info?) and if it's a PARM_DECL then it may change the ABI
> (in which case their SSA names maybe should have overaligned type...)

	Jakub