[Bug bootstrap/71071] [7 regression] ICE --enable-checking=fold : fold check: original tree changed by fold

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71071

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Then we need something like:
--- gcc/fold-const.c.jj 2016-05-11 15:15:49.000000000 +0200
+++ gcc/fold-const.c    2016-05-13 10:31:05.693911428 +0200
@@ -12130,7 +12130,8 @@ fold_checksum_tree (const_tree expr, str
               || TYPE_REFERENCE_TO (expr)
               || TYPE_CACHED_VALUES_P (expr)
               || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)
-              || TYPE_NEXT_VARIANT (expr)))
+              || TYPE_NEXT_VARIANT (expr)
+              || TYPE_ALIAS_SET_KNOWN_P (expr)))
     {
       /* Allow these fields to be modified.  */
       tree tmp;
@@ -12140,6 +12141,7 @@ fold_checksum_tree (const_tree expr, str
       TYPE_POINTER_TO (tmp) = NULL;
       TYPE_REFERENCE_TO (tmp) = NULL;
       TYPE_NEXT_VARIANT (tmp) = NULL;
+      TYPE_ALIAS_SET (tmp) = -1;
       if (TYPE_CACHED_VALUES_P (tmp))
        {
          TYPE_CACHED_VALUES_P (tmp) = 0;