[committed] analyzer: fold -(-(VAL)) to VAL

[David Malcolm via Gcc-patches]

Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Pushed to trunk as 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 <dmalc...@redhat.com>
---
 gcc/analyzer/region-model-manager.cc | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/gcc/analyzer/region-model-manager.cc 
b/gcc/analyzer/region-model-manager.cc
index ed5b9c75910..1956cfc3e8d 100644
--- a/gcc/analyzer/region-model-manager.cc
+++ b/gcc/analyzer/region-model-manager.cc
@@ -432,6 +432,17 @@ 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.  */
-- 
2.26.3