tree-ssa-sccvn.c (vn_reference_lookup_3): Don't assume there are more…

tree-ssa-sccvn.c (vn_reference_lookup_3): Don't assume there are more VR->OPERANDS than LHS operands.

* tree-ssa-sccvn.c (vn_reference_lookup_3): Don't assume there are
        more VR->OPERANDS than LHS operands.  Free LHS before returning.

From-SVN: r151530

gcc/ChangeLog

@@ -89,6 +89,11 @@
 	(remove_from_deps): Also remove calls from
 	last_function_call_may_noreturn list.
 
+2009-09-07  Richard Henderson  <rth@redhat.com>
+
+	* tree-ssa-sccvn.c (vn_reference_lookup_3): Don't assume there are
+	more VR->OPERANDS than LHS operands.  Free LHS before returning.
+
 2009-09-07  Bernd Schmidt  <bernd.schmidt@analog.com>
 
 	* config/bfin/bfin.md (UNSPEC_VOLATILE_STALL): New constant.

gcc/tree-ssa-sccvn.c

@@ -1120,7 +1120,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_)
       copy_reference_ops_from_ref (gimple_assign_lhs (def_stmt), &lhs);
       i = VEC_length (vn_reference_op_s, vr->operands) - 1;
       j = VEC_length (vn_reference_op_s, lhs) - 1;
-      while (j >= 0
+      while (j >= 0 && i >= 0
 	     && vn_reference_op_eq (VEC_index (vn_reference_op_s,
 					       vr->operands, i),
 				    VEC_index (vn_reference_op_s, lhs, j)))
@@ -1128,13 +1128,14 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_)
 	  i--;
 	  j--;
 	}
+
+      VEC_free (vn_reference_op_s, heap, lhs);
       /* i now points to the first additional op.
 	 ???  LHS may not be completely contained in VR, one or more
 	 VIEW_CONVERT_EXPRs could be in its way.  We could at least
 	 try handling outermost VIEW_CONVERT_EXPRs.  */
       if (j != -1)
 	return (void *)-1;
-      VEC_free (vn_reference_op_s, heap, lhs);
 
       /* Now re-write REF to be based on the rhs of the assignment.  */
       copy_reference_ops_from_ref (gimple_assign_rhs1 (def_stmt), &rhs);