diff --git a/modules/src/flt_arith/flt_chk.c b/modules/src/flt_arith/flt_chk.c
index 2a027d014..1ec3a1671 100644
--- a/modules/src/flt_arith/flt_chk.c
+++ b/modules/src/flt_arith/flt_chk.c
@@ -15,12 +15,14 @@ flt_chk(e)
 	if (e->flt_exp >= EXT_MAX) {
 		flt_status = FLT_OVFL;
 		e->flt_exp = EXT_MAX;
-		e->m1 = e->m2 = 0;
+		e->m1 = 0x80000000;
+		e->m2 = 0;
 	}
 	if (e->flt_exp <= EXT_MIN) {
 		flt_status = FLT_UNFL;
 		e->flt_exp = 0;
-		e->m1 = e->m2 = 0;
+		e->m1 = 0;
+		e->m2 = 0;
 		e->flt_sign = 0;
 	}
 }
diff --git a/modules/src/flt_arith/flt_cmp.c b/modules/src/flt_arith/flt_cmp.c
index fd21a9b40..847c8989e 100644
--- a/modules/src/flt_arith/flt_cmp.c
+++ b/modules/src/flt_arith/flt_cmp.c
@@ -11,9 +11,14 @@ int
 flt_cmp(e1, e2)
 	register flt_arith *e1, *e2;
 {
-	int sign = e1->flt_sign ? -1 : 1;
+	int sign;
 	int tmp;
 
+	if (e1->flt_exp == 0 && e1->m1 == 0 && e1->m2 == 0 &&
+	    e2->flt_exp == 0 && e2->m1 == 0 && e2->m2 == 0) {
+		return 0;
+	}
+	sign = e1->flt_sign ? -1 : 1;
 	if (e1->flt_sign > e2->flt_sign) return -1;
 	if (e1->flt_sign < e2->flt_sign) return 1;
 	if (e1->flt_exp < e2->flt_exp) return -sign;
diff --git a/modules/src/flt_arith/flt_div.c b/modules/src/flt_arith/flt_div.c
index 82fe7b120..39134bea4 100644
--- a/modules/src/flt_arith/flt_div.c
+++ b/modules/src/flt_arith/flt_div.c
@@ -22,7 +22,8 @@ flt_div(e1,e2,e3)
 	if ((e2->m1 | e2->m2) == 0) {
 		flt_status = FLT_DIV0;
 		e3->flt_exp = EXT_MAX;
-		e3->m1 = e3->m2 = 0L;
+		e3->m1 = 0x80000000;
+		e3->m2 = 0L;
 		return;
 	}
 	if ((e1->m1 | e1->m2) == 0) {	/* 0 / anything == 0 */
diff --git a/modules/src/flt_arith/flt_nrm.c b/modules/src/flt_arith/flt_nrm.c
index 988d8565d..107071a6f 100644
--- a/modules/src/flt_arith/flt_nrm.c
+++ b/modules/src/flt_arith/flt_nrm.c
@@ -10,8 +10,11 @@
 flt_nrm(e)
 	register flt_arith *e;
 {
-	if ((e->m1 | e->m2) == 0L)
+	if ((e->m1 | e->m2) == 0L) {
+		e->flt_exp = 0;
+		e->flt_sign = 0;
 		return;
+	}
 
 	/* if top word is zero mov low word	*/
 	/* to top word, adjust exponent value	*/
diff --git a/modules/src/flt_arith/flt_str2fl.c b/modules/src/flt_arith/flt_str2fl.c
index bc178a131..9a3b20e25 100644
--- a/modules/src/flt_arith/flt_str2fl.c
+++ b/modules/src/flt_arith/flt_str2fl.c
@@ -253,7 +253,7 @@ flt_str2flt(s, e)
 	while (c = *s++, isdigit(c) || (c == '.' && ! dotseen++)) {
 		if (c == '.') continue;
 		digitseen = 1;
-		if (e->m1 <= 0x7FFFFFFF/5) {
+		if (e->m1 >= 0 && e->m1 <= 0x7FFFFFFF/5) {
 			struct flt_mantissa	a1;
 
 			a1 = e->flt_mantissa;
@@ -415,7 +415,7 @@ flt_flt2str(e, buf, bufsize)
                 if (*s1) *s++ = *s1++;
                 else *s++ = '0';
 	}
-        if ((e->m1 | e->m2) || e->flt_exp == EXT_MIN || e->flt_exp == EXT_MAX) {
+        if (e->m1 | e->m2) {
 		--dp ;
 	}
 	if (dp != 0) {