On May 4, 2017 6:03:46 PM GMT+02:00, Jakub Jelinek <ja...@redhat.com> wrote: >On Thu, May 04, 2017 at 05:54:47PM +0200, Richard Biener wrote: >> >2017-05-04 Jakub Jelinek <ja...@redhat.com> >> > >> > * tree.c (next_type_uid): Change type to unsigned. >> > (type_hash_canon): Decrement back next_type_uid if >> > freeing a type node with the highest TYPE_UID. For INTEGER_TYPEs >> > also ggc_free TYPE_MIN_VALUE, TYPE_MAX_VALUE and TYPE_CACHED_VALUES >> > if possible. >> > >> >--- gcc/tree.c.jj 2017-05-03 16:55:39.688052581 +0200 >> >+++ gcc/tree.c 2017-05-03 18:49:30.662185944 +0200 >> >@@ -151,7 +151,7 @@ static const char * const tree_node_kind >> > /* Unique id for next decl created. */ >> > static GTY(()) int next_decl_uid; >> > /* Unique id for next type created. */ >> >-static GTY(()) int next_type_uid = 1; >> >+static GTY(()) unsigned next_type_uid = 1; >> > /* Unique id for next debug decl created. Use negative numbers, >> > to catch erroneous uses. */ >> > static GTY(()) int next_debug_decl_uid; >> >@@ -7188,6 +7188,19 @@ type_hash_canon (unsigned int hashcode, >> > { >> > tree t1 = ((type_hash *) *loc)->type; >> > gcc_assert (TYPE_MAIN_VARIANT (t1) == t1); >> >+ if (TYPE_UID (type) + 1 == next_type_uid) >> >+ --next_type_uid; >> >+ if (TREE_CODE (type) == INTEGER_TYPE) >> >+ { >> >+ if (TYPE_MIN_VALUE (type) >> >+ && TREE_TYPE (TYPE_MIN_VALUE (type)) == type) >> >+ ggc_free (TYPE_MIN_VALUE (type)); >> >+ if (TYPE_MAX_VALUE (type) >> >+ && TREE_TYPE (TYPE_MAX_VALUE (type)) == type) >> >+ ggc_free (TYPE_MAX_VALUE (type)); >> >+ if (TYPE_CACHED_VALUES_P (type)) >> >+ ggc_free (TYPE_CACHED_VALUES (type)); >> >+ } >> > free_node (type); >> >> Shouldn't free_node handle this? That said, is freeing min/max safe? > The constants are shared after all. > >The next_type_uid handling, I think it is better in type_hash_canon,
Agreed. >the >only other user after all calls free_node in a loop, so it is highly >unlikely it would do anything there. > >If you mean the INTEGER_TYPE handling, then yes, I guess it could be >done in free_node too and can move it there. If it was without >the && TREE_TYPE (TYPE_M*_VALUE (type)) == type extra checks, then it >is certainly unsafe and breaks bootstrap even, e.g. build_range_type >and other spots happily create INTEGER_TYPEs with min/max value that >have some other type. But when the type of the INTEGER_CSTs is the >type we are ggc_freeing, anything that would refer to those constants >afterwards would be necessarily broken (as their TREE_TYPE would be >ggc_freed, possibly reused for something completely unrelated). >Thus I think it should be safe even in the LTO case and thus doable >in free_node. OK. OTOH LTO frees the whole SCC and thus doesn't expect any pointed to stuff to be freed. Not sure if we allow double ggc_free of stuff. Richard. > > Jakub