On Wed, 13 Aug 2014, Jason Merrill wrote:
> On 08/13/2014 10:28 AM, Richard Biener wrote:
> > Sofar the patch survived building stage2 in a LTO bootstrap on the
> > 4.9 branch, full testing is scheduled for trunk.
>
> The patch breaks a lot of C++ testcases, such as
> g++.old-deja/g++.other/cvt1.C; I think you need to share the "set the
> canonical type" code with the template path.
>
> > Jason, are you happy with that (esp. ripping out the odd
> > type completion stuff that also messes with types recorded in
> > said hashtable)?
>
> I'm nervous about it, since it leads to ARRAY_TYPEs with different TYPE_ALIGN
> than their elements, though I'm not sure this actually breaks anything.
> Perhaps we could copy TYPE_ALIGN and TYPE_USER_ALIGN at the same place we copy
> TYPE_NEEDS_CONSTRUCTING.
Um, ok. I don't feel like fiddling with this C++ frontend part and
am going to try workaround it in tree.c with sth like
Index: gcc/tree.c
===================================================================
--- gcc/tree.c (revision 213814)
+++ gcc/tree.c (working copy)
@@ -6759,6 +6759,13 @@ type_hash_canon (unsigned int hashcode,
t1 = type_hash_lookup (hashcode, type);
if (t1 != 0)
{
+ if (TYPE_MAIN_VARIANT (t1) != t1)
+ {
+ /* Oops. C++ FE fun. Overwrite the entry. */
+ type_hash_add (hashcode, type);
+ return type;
+ }
+ gcc_assert (TYPE_MAIN_VARIANT (t1) == t1);
if (GATHER_STATISTICS)
{
tree_code_counts[(int) TREE_CODE (type)]--;
as I seem to have other GC-related LTO IL differences to chase.
So - can you take over this C++ frontend issue?
Thanks,
Richard.
