diff --git a/src/cnglob.h b/src/cnglob.h
index 5bfc4e552..a508ebdfc 100644
--- a/src/cnglob.h
+++ b/src/cnglob.h
@@ -182,8 +182,12 @@ typedef std::string WStr;
 /*------------------------------- math -------------------------------------*/
 // error handling
 extern UINT doControlFP();
+#ifdef _WIN32
 #define FPCHECK __asm { fwait }	// trap pending FP exception (if any)
 								//   re searching for FP exceptions
+#else
+#define FPCHECK
+#endif
 
 // min and max (converted to template fcns, 10-12)
 #undef min
diff --git a/src/cnloads.cpp b/src/cnloads.cpp
index 2abbbf018..a4746f80b 100644
--- a/src/cnloads.cpp
+++ b/src/cnloads.cpp
@@ -3381,13 +3381,13 @@ RC RSYS::rs_EndSubhr()
 	// verify RSYSRES_IVL_SUB layout at compile time
 	// fixed sequence allows array access by rs_mode (see code below)
 	// rsmHEAT/rsmCOOL/rsmOAV definitions must be consistent with member sequences.
-#define QZONECHK( m, oDif) static_assert( &((RSYSRES_IVL_SUB *)0)->m-&((RSYSRES_IVL_SUB *)0)->qhZoneSen == oDif, "Bad seq " #m)
+#define QZONECHK( m, oDif) static_assert( offsetof(RSYSRES_IVL_SUB, m) - offsetof(RSYSRES_IVL_SUB, qhZoneSen) == oDif, "Bad seq " #m)
 	QZONECHK(qhZoneSen, (rsmHEAT - 1) * 2);
-	QZONECHK(qhZoneLat, (rsmHEAT - 1) * 2 + 1);
-	QZONECHK(qcZoneSen, (rsmCOOL - 1) * 2);
-	QZONECHK(qcZoneLat, (rsmCOOL - 1) * 2 + 1);
-	QZONECHK(qvZoneSen, (rsmOAV - 1) * 2);
-	QZONECHK(qvZoneLat, (rsmOAV - 1) * 2 + 1);
+	QZONECHK(qhZoneLat, (rsmHEAT - 1) * 2 + sizeof(float));
+	QZONECHK(qcZoneSen, (rsmCOOL - 1) * 2 * sizeof(float));
+	QZONECHK(qcZoneLat, (rsmCOOL - 1) * 2 * sizeof(float) + sizeof(float));
+	QZONECHK(qvZoneSen, (rsmOAV - 1) * 2 * sizeof(float));
+	QZONECHK(qvZoneLat, (rsmOAV - 1) * 2 * sizeof(float) + sizeof(float));
 	static_assert(rsmCOUNT == 4, "Bad rsm enum");
 #undef QZONECHK