From a3bc77cd7bcd50f49388c789d4e42603102235a6 Mon Sep 17 00:00:00 2001
From: Alan Mishchenko <alanmi@berkeley.edu>
Date: Tue, 3 Dec 2013 00:03:09 -0800
Subject: Making 'fold' and 'unfold' skip constant POs.

---
 src/aig/saig/saigConstr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/aig/saig/saigConstr.c b/src/aig/saig/saigConstr.c
index 5f54ef83..f8782e5f 100644
--- a/src/aig/saig/saigConstr.c
+++ b/src/aig/saig/saigConstr.c
@@ -283,6 +283,8 @@ Aig_Man_t * Saig_ManDupUnfoldConstrs( Aig_Man_t * pAig )
     vConsAll = Vec_PtrAlloc( Saig_ManPoNum(pAig) );
     Saig_ManForEachPo( pAig, pObj, i )
     {
+        if ( Aig_ObjFanin0(pObj) == Aig_ManConst1(pAig) )
+            continue;
         RetValue = Saig_ManDetectConstr( pAig, i, &vOuts, &vCons );
         if ( RetValue == 0 )
         {
@@ -392,6 +394,8 @@ Aig_Man_t * Saig_ManDupFoldConstrs( Aig_Man_t * pAig, Vec_Int_t * vConstrs )
     // create primary output
     Saig_ManForEachPo( pAig, pObj, i )
     {
+        if ( Aig_ObjFanin0(pObj) == Aig_ManConst1(pAig) )
+            continue;
         pMiter = Aig_And( pAigNew, Aig_ObjChild0Copy(pObj), Aig_Not(pFlopIn) );
         Aig_ObjCreateCo( pAigNew, pMiter );
     }
-- 
cgit v1.2.3