analyzer: fold -(-(VAL)) to VAL

Cherrypicked from r13-3075-g7f42f7adfa69fe.

gcc/analyzer/ChangeLog:
	* region-model-manager.cc
	(region_model_manager::maybe_fold_unaryop): Fold -(-(VAL)) to VAL.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

diff --git a/gcc/analyzer/region-model-manager.cc b/gcc/analyzer/region-model-manager.cc
index 6d248c98fcfc87b684192b41e946de18fa83f541..a5977c1d6b49e20054d799c73f26eb6bec926457 100644 (file)
--- a/gcc/analyzer/region-model-manager.cc
+++ b/gcc/analyzer/region-model-manager.cc
@@ -430,6 +430,17 @@ region_model_manager::maybe_fold_unaryop (tree type, enum tree_code op,
            }
       }
       break;
+    case NEGATE_EXPR:
+      {
+       /* -(-(VAL)) is VAL, for integer types.  */
+       if (const unaryop_svalue *unaryop = arg->dyn_cast_unaryop_svalue ())
+         if (unaryop->get_op () == NEGATE_EXPR
+             && type == unaryop->get_type ()
+             && type
+             && INTEGRAL_TYPE_P (type))
+           return unaryop->get_arg ();
+      }
+      break;
     }
 
   /* Constants.  */