On Thu, Jul 18, 2013 at 10:45:19AM -0600, Jeff Law wrote:
> If I understand you correctly, you're claiming that the DECL_UID can
> vary based on whether or not we're emitting debug info. This can be
> seen in iterative_hash_expr:
Yes, for e.g. SSA_NAME_VERSION, we require that it is the same in between
-g -fvar-tracking-assignments and -g0, for DECL_UIDs, only the relative
ordering must be preserved, as in, for VTA the gaps between DECL_UID
of decls seen both in -g0 and -g code can be bigger.
So -g0 can use for decls a, c, b uids say 12 13 14, while -g can use
12 27 39. Thus hashing the DECL_UID if e.g. the hash table is later on
traversed could lead to -fcompare-debug failures.
Jakub
