This avoids the odd cases where gimple_register_canonical_type could
end up running in cycles. I was able to reproduce this issue
with an intermediate tree and LTO bootstrap. While the following
patch is not the "real" fix (that one runs into a known cache-preloading
issue again ...) it certainly makes a lot of sense and avoids
the issue by design.
LTO bootstrapped on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2011-05-17 Richard Guenther <rguent...@suse.de>
* gimple.c (gimple_register_canonical_type): Use the main-variant
leader for computing the canonical type.
Index: gcc/gimple.c
===================================================================
*** gcc/gimple.c (revision 173825)
--- gcc/gimple.c (working copy)
*************** gimple_register_canonical_type (tree t)
*** 4856,4874 ****
if (TYPE_CANONICAL (t))
return TYPE_CANONICAL (t);
! /* Always register the type itself first so that if it turns out
! to be the canonical type it will be the one we merge to as well. */
! t = gimple_register_type (t);
if (TYPE_CANONICAL (t))
return TYPE_CANONICAL (t);
- /* Always register the main variant first. This is important so we
- pick up the non-typedef variants as canonical, otherwise we'll end
- up taking typedef ids for structure tags during comparison. */
- if (TYPE_MAIN_VARIANT (t) != t)
- gimple_register_canonical_type (TYPE_MAIN_VARIANT (t));
-
if (gimple_canonical_types == NULL)
gimple_canonical_types = htab_create_ggc (16381,
gimple_canonical_type_hash,
gimple_canonical_type_eq, 0);
--- 4856,4869 ----
if (TYPE_CANONICAL (t))
return TYPE_CANONICAL (t);
! /* Use the leader of our main variant for determining our canonical
! type. The main variant leader is a type that will always
! prevail. */
! t = gimple_register_type (TYPE_MAIN_VARIANT (t));
if (TYPE_CANONICAL (t))
return TYPE_CANONICAL (t);
if (gimple_canonical_types == NULL)
gimple_canonical_types = htab_create_ggc (16381,
gimple_canonical_type_hash,
gimple_canonical_type_eq, 0);
