try to catch isinf over ieeefp.h

ChangeLog

@@ -1,6 +1,7 @@
 2009-01-04 Dietmar Warning
  * src/math/misc/isinf.c, Makefile.am: a simple (but ugly) workaround for isinf 
    needed by some adms generated models
+ * src/iclude/ngspice.h, missing_math.h: try to catch isinf by ieeefp.h
  * adms/ekv/amsva/ekv.va: compatibility regarding S/D diode behaviour
 
 2009-01-02 Dietmar Warning

src/include/missing_math.h

@@ -33,13 +33,17 @@ extern int isnan(double);
 #endif
 
 #ifndef HAVE_DECL_ISINF
-# ifndef HAVE_ISINF
-#  if defined(HAVE_FINITE) && (defined (HAVE_DECL_ISNAN) || defined (HAVE_ISNAN))
-#   define isinf(x) (!finite(x) && !isnan(x))
-#  endif
-# else
-extern int isinf(double);
-# endif
+#ifndef HAVE_ISINF
+#if defined(HAVE_FINITE) && (defined (HAVE_DECL_ISNAN) || defined (HAVE_ISNAN))
+#define isinf(x) (!finite(x) && !isnan(x))
+#else
+#ifdef HAVE_IEEEFP_H
+    extern int isinf(double);
 #endif
+#endif
+#else  /* HAVE_ISINF */
+  extern int isinf(double);
+#endif /* HAVE_ISINF */
+#endif /* HAVE_DECL_ISINF */
 
 #endif /* MISSING_MATH_H_INCLUDED */

src/include/ngspice.h

@@ -31,6 +31,10 @@
 #include <math.h>
 #include <stdio.h>
 
+#ifdef HAVE_IEEEFP_H
+#include <ieeefp.h>
+#endif
+
 #include "missing_math.h"
 
 #ifdef STDC_HEADERS

src/maths/misc/isinf.c

@@ -1,26 +1,35 @@
 #include "ngspice.h"
 
-/* this is really ugly - but it is a emergency case */
-
 #ifndef HAVE_DECL_ISINF
+
 #ifndef HAVE_ISINF
 
-static int
-isinf(double x)
-{
-    volatile double a = x;
+#ifdef HAVE_IEEEFP_H
 
-    if (a > DBL_MAX)
-        return 1;
-    if (a < -DBL_MAX)
-        return -1;
-    return 0;
-}
+  int isinf(double x) { return !finite(x) && x==x; }
+
+#else /* HAVE_IEEEFP_H */
+
+  /* this is really ugly - but it is a emergency case */
+  
+  static int
+  isinf(double x)
+  {
+      volatile double a = x;
+  
+      if (a > DBL_MAX)
+          return 1;
+      if (a < -DBL_MAX)
+          return -1;
+      return 0;
+  }
+
+#endif /* HAVE_IEEEFP_H */
 
-/*
- * end isinf.c
- */
 #else /* HAVE_ISINF */
-int Dummy_Symbol_5;
+
+  int Dummy_Symbol_5;
+
 #endif /* HAVE_ISINF */
+
 #endif /* HAVE_DECL_ISINF */