re PR lto/63704 (-flto internal compiler error: in mems_in_disjoint_alias_sets_p, at alias.c:398)

2014-11-27  Richard Biener  <rguenther@suse.de>

	PR middle-end/63704
	* alias.c (mems_in_disjoint_alias_sets_p): Remove assert
	and instead return false when !fstrict-aliasing.

From-SVN: r218114

gcc/ChangeLog

 2014-11-27  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/63704
+	* alias.c (mems_in_disjoint_alias_sets_p): Remove assert
+	and instead return false when !fstrict-aliasing.
+
+2014-11-27  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/61634
 	* tree-vect-slp.c: Include gimple-walk.h.
 	(vect_detect_hybrid_slp_stmts): Rewrite to propagate hybrid

gcc/alias.c

@@ -417,17 +417,9 @@ get_alias_set_entry (alias_set_type alias_set)
 static inline int
 mems_in_disjoint_alias_sets_p (const_rtx mem1, const_rtx mem2)
 {
-/* Perform a basic sanity check.  Namely, that there are no alias sets
-   if we're not using strict aliasing.  This helps to catch bugs
-   whereby someone uses PUT_CODE, but doesn't clear MEM_ALIAS_SET, or
-   where a MEM is allocated in some way other than by the use of
-   gen_rtx_MEM, and the MEM_ALIAS_SET is not cleared.  If we begin to
-   use alias sets to indicate that spilled registers cannot alias each
-   other, we might need to remove this check.  */
-  gcc_assert (flag_strict_aliasing
-	      || (!MEM_ALIAS_SET (mem1) && !MEM_ALIAS_SET (mem2)));
-
-  return ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), MEM_ALIAS_SET (mem2));
+  return (flag_strict_aliasing
+	  && ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1),
+				      MEM_ALIAS_SET (mem2)));
 }
 
 /* Return true if the first alias set is a subset of the second.  */