From 6b00a88f286b75b67ff78b5406152164c4b17e62 Mon Sep 17 00:00:00 2001
From: stefan schippers <stefan.schippers@gmail.com>
Date: Sun, 8 Oct 2023 11:45:22 +0200
Subject: [PATCH] fix xschem simulator "mux" operator (M) to handle unknown
 selector state

---
 src/hilight.c                             | 2 +-
 xschem_library/xschem_simulator/dev-1.sym | 4 ++--
 xschem_library/xschem_simulator/dev-2.sym | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/hilight.c b/src/hilight.c
index 4c96e8d3..49f5f8c1 100644
--- a/src/hilight.c
+++ b/src/hilight.c
@@ -1380,7 +1380,7 @@ static int eval_logic_expr(int inst, int output)
         if(sp > 2) {
           s = stack[sp - 1];
           if(s < 2) {
-            stack[sp - 3] = (s == 0) ? stack[sp - 3]  : stack[sp - 2];
+            stack[sp - 3] = (s == 0) ? stack[sp - 3] : (s == 1) ? stack[sp - 2] : 2;
           }
           else stack[sp - 3] = 2; /* setting to 2 (X) may lead to simulation deadlocks */
           sp -=2;
diff --git a/xschem_library/xschem_simulator/dev-1.sym b/xschem_library/xschem_simulator/dev-1.sym
index 91cc2026..b21e1a2c 100644
--- a/xschem_library/xschem_simulator/dev-1.sym
+++ b/xschem_library/xschem_simulator/dev-1.sym
@@ -2,8 +2,8 @@ v {xschem version=3.4.5 file_version=1.2
 }
 G {}
 K {type=switch
-function1="0 Z 3 m"
-function2="Z 0 3 m"
+function1="0 Z 3 M"
+function2="Z 0 3 M"
 template="name=s1"
 }
 V {}
diff --git a/xschem_library/xschem_simulator/dev-2.sym b/xschem_library/xschem_simulator/dev-2.sym
index 56342996..4ab53e33 100644
--- a/xschem_library/xschem_simulator/dev-2.sym
+++ b/xschem_library/xschem_simulator/dev-2.sym
@@ -2,7 +2,7 @@ v {xschem version=3.4.5 file_version=1.2
 }
 G {}
 K {type=switch
-function0="1 2 3 m"
+function0="1 2 3 M"
 template="name=s1"
 format="* @name @pinlist @symname"
 }