From a18ac9c47449efce84c3c37576a197fb559fc99c Mon Sep 17 00:00:00 2001
From: h_vogt <h_vogt>
Date: Tue, 22 Dec 2015 00:02:45 +0100
Subject: [PATCH] include/ngspice/cm.h, xspice, introduce NAN for visual studio

---
 src/include/ngspice/cm.h              | 11 +++++++++++
 src/xspice/icm/xtradev/core/cfunc.mod |  4 ++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/include/ngspice/cm.h b/src/include/ngspice/cm.h
index 281880fcb..f1bd493c2 100644
--- a/src/include/ngspice/cm.h
+++ b/src/include/ngspice/cm.h
@@ -45,5 +45,16 @@ NON-STANDARD FEATURES
 #include "ngspice/cmproto.h"
 #include "ngspice/mifcmdat.h"
 
+#if defined (_MSC_VER)
+#ifndef NAN
+    static const __int64 global_nan = 0x7ff8000000000000i64;
+    #define NAN (*(const double *) &global_nan)
+#endif
+#endif
+
+#if !defined(NAN)
+#define NAN (0.0/0.0)
+#endif
+
 
 #endif
diff --git a/src/xspice/icm/xtradev/core/cfunc.mod b/src/xspice/icm/xtradev/core/cfunc.mod
index d88f691f9..86c2786c7 100644
--- a/src/xspice/icm/xtradev/core/cfunc.mod
+++ b/src/xspice/icm/xtradev/core/cfunc.mod
@@ -294,8 +294,8 @@ cm_core(ARGS)
             /*** must determine position progressively & then ***/
             /*** calculate required output. ***/
 
-            dout_din = 0.0 / 0.0;
-            B_out    = 0.0 / 0.0;
+            dout_din = NAN;
+            B_out    = NAN;
 
             for (i = 1; i < size; i++)
                 if (H_input < (H[i].rvalue + H[i+1].rvalue) / 2.0) {