--- a/QuadFloat.st	Thu Jun 06 22:55:04 2019 +0200
+++ b/QuadFloat.st	Thu Jun 06 23:01:38 2019 +0200
@@ -13,6 +13,11 @@
 !QuadFloat primitiveDefinitions!
 
 %{
+#if __POINTER_SIZE__ == 8
+# define SUPPORT_QUADFLOAT
+#endif
+
+#ifdef SUPPORT_QUADFLOAT
 /*----------------------------------------------------------------------------
 | Software floating-point underflow tininess-detection mode.
 *----------------------------------------------------------------------------*/
@@ -78,12 +83,16 @@
 };
 struct exp16_sig64 { int_fast16_t exp; uint_fast64_t sig; };
 
+#endif // SUPPORT_QUADFLOAT
+
 %}
 ! !
 
 !QuadFloat primitiveVariables!
 
 %{
+#ifdef SUPPORT_QUADFLOAT
+
 uint_fast8_t softfloat_exceptionFlags;
 uint_fast8_t softfloat_roundingMode = softfloat_round_near_even;
 uint_fast8_t softfloat_detectTininess = init_detectTininess;
@@ -107,12 +116,15 @@
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 };
+#endif // SUPPORT_QUADFLOAT
+
 %}
 ! !
 
 !QuadFloat primitiveFunctions!
 
 %{
+#ifdef SUPPORT_QUADFLOAT
 
 #if defined(LITTLEENDIAN) || defined(__LSB_FIRST__)
 #define wordIncr 1
@@ -842,6 +854,7 @@
     }
 
 }
+#endif // SUPPORT_QUADFLOAT
 
 %}
 ! !
@@ -898,7 +911,7 @@
       binary stored in a device independent format)."
 
 %{  /* NOCONTEXT */
-#ifndef __SCHTEAM__
+#ifdef SUPPORT_QUADFLOAT
     OBJ newFloat;
 
     if (sizeof(long double) == sizeof(float128_t)) {
@@ -909,8 +922,9 @@
 	__qMKQFLOAT(newFloat, qf);   /* OBJECT ALLOCATION */
     }
     RETURN (newFloat);
-#endif /* not SCHTEAM */
-%}
+#endif /* SUPPORT_QUADFLOAT */
+%}.
+    self error:'QuadFloats not supported on this patform'
 
     "Created: / 06-06-2019 / 17:18:58 / Claus Gittinger"
 !
@@ -919,7 +933,7 @@
     "return a new quadFloat, given a float value"
 
 %{  /* NOCONTEXT */
-#ifndef __SCHTEAM__
+#ifdef SUPPORT_QUADFLOAT
     OBJ newFloat;
     float128_t f;
 
@@ -931,8 +945,11 @@
 	__qMKQFLOAT(newFloat, qf);   /* OBJECT ALLOCATION */
 	RETURN (newFloat);
     }
-#endif
+#endif /* SUPPORT_QUADFLOAT */
 %}.
+    aFloat isFloat ifTrue:[
+	self error:'QuadFloats not supported on this patform'
+    ].
     self error:'invalid argument'
 
     "