diff --git a/src/V3AstNodes.h b/src/V3AstNodes.h
index 0be2fa713..4729b2264 100644
--- a/src/V3AstNodes.h
+++ b/src/V3AstNodes.h
@@ -3076,7 +3076,7 @@ struct AstLogIf : public AstNodeBiop {
     AstLogIf(FileLine* fl, AstNode* lhsp, AstNode* rhsp) : AstNodeBiop(fl, lhsp, rhsp) {
 	dtypeSetLogicBool(); }
     ASTNODE_NODE_FUNCS(LogIf, LOGIF)
-    virtual void numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs) { V3ERROR_NA; }
+    virtual void numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs) { out.opLogIf(lhs,rhs); }
     virtual string emitVerilog() { return "%k(%l %f-> %r)"; }
     virtual string emitC() { return "VL_LOGIF_%nq%lq%rq(%nw,%lw,%rw, %P, %li, %ri)"; }
     virtual string emitSimpleOperator() { return "->"; }
@@ -3089,7 +3089,7 @@ struct AstLogIff : public AstNodeBiCom {
     AstLogIff(FileLine* fl, AstNode* lhsp, AstNode* rhsp) : AstNodeBiCom(fl, lhsp, rhsp) {
 	dtypeSetLogicBool(); }
     ASTNODE_NODE_FUNCS(LogIff, LOGIFF)
-    virtual void numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs) { V3ERROR_NA; }
+    virtual void numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs) { out.opLogIff(lhs,rhs); }
     virtual string emitVerilog() { return "%k(%l %f<-> %r)"; }
     virtual string emitC() { return "VL_LOGIFF_%nq%lq%rq(%nw,%lw,%rw, %P, %li, %ri)"; }
     virtual string emitSimpleOperator() { return "<->"; }
diff --git a/src/V3Number.cpp b/src/V3Number.cpp
index efba062e7..fba516467 100644
--- a/src/V3Number.cpp
+++ b/src/V3Number.cpp
@@ -916,6 +916,18 @@ last:
     return setSingleBits(outc);
 }
 
+V3Number& V3Number::opLogIf (const V3Number& lhs, const V3Number& rhs) {
+    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to
+    // X/Z extend. Use opLogNot and opLogOr to do this for us.
+    return opLogOr(opLogNot(lhs), rhs);
+}
+
+V3Number& V3Number::opLogIff (const V3Number& lhs, const V3Number& rhs) {
+    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to
+    // X/Z extend. Use opLogNot and opLogXor to do this for us.
+    return opLogNot(opXor(lhs, rhs));
+}
+
 V3Number& V3Number::opEq (const V3Number& lhs, const V3Number& rhs) {
     // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
     char outc = 1;
diff --git a/src/V3Number.h b/src/V3Number.h
index c507ca9da..86d15b2d9 100644
--- a/src/V3Number.h
+++ b/src/V3Number.h
@@ -227,6 +227,8 @@ public:
     V3Number& opLogNot	(const V3Number& lhs);
     V3Number& opLogAnd	(const V3Number& lhs, const V3Number& rhs);
     V3Number& opLogOr	(const V3Number& lhs, const V3Number& rhs);
+    V3Number& opLogIf	(const V3Number& lhs, const V3Number& rhs);
+    V3Number& opLogIff	(const V3Number& lhs, const V3Number& rhs);
     V3Number& opAbsS    (const V3Number& lhs);
     V3Number& opNegate	(const V3Number& lhs);
     V3Number& opAdd	(const V3Number& lhs, const V3Number& rhs);