diff --git a/src/compiler.ts b/src/compiler.ts
index b637192733..6dded2c241 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -3779,7 +3779,7 @@ export class Compiler extends DiagnosticEmitter {
 
         rightExpr = this.compileExpression(right, leftType);
         rightType = this.currentType;
-        commonType = Type.commonDenominator(leftType, rightType, true);
+        commonType = Type.commonType(leftType, rightType, contextualType, true);
         if (!commonType || !commonType.isNumericValue) {
           this.error(
             DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -3814,7 +3814,7 @@ export class Compiler extends DiagnosticEmitter {
 
         rightExpr = this.compileExpression(right, leftType);
         rightType = this.currentType;
-        commonType = Type.commonDenominator(leftType, rightType, true);
+        commonType = Type.commonType(leftType, rightType, contextualType, true);
         if (!commonType || !commonType.isNumericValue) {
           this.error(
             DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -3849,7 +3849,7 @@ export class Compiler extends DiagnosticEmitter {
 
         rightExpr = this.compileExpression(right, leftType);
         rightType = this.currentType;
-        commonType = Type.commonDenominator(leftType, rightType, true);
+        commonType = Type.commonType(leftType, rightType, contextualType, true);
         if (!commonType || !commonType.isNumericValue) {
           this.error(
             DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -3884,7 +3884,7 @@ export class Compiler extends DiagnosticEmitter {
 
         rightExpr = this.compileExpression(right, leftType);
         rightType = this.currentType;
-        commonType = Type.commonDenominator(leftType, rightType, true);
+        commonType = Type.commonType(leftType, rightType, contextualType, true);
         if (!commonType || !commonType.isNumericValue) {
           this.error(
             DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -3921,7 +3921,7 @@ export class Compiler extends DiagnosticEmitter {
 
         rightExpr = this.compileExpression(right, leftType);
         rightType = this.currentType;
-        commonType = Type.commonDenominator(leftType, rightType, false);
+        commonType = Type.commonType(leftType, rightType, contextualType);
         if (!commonType) {
           this.error(
             DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -3973,7 +3973,7 @@ export class Compiler extends DiagnosticEmitter {
 
         rightExpr = this.compileExpression(right, leftType);
         rightType = this.currentType;
-        commonType = Type.commonDenominator(leftType, rightType, false);
+        commonType = Type.commonType(leftType, rightType, contextualType);
         if (!commonType) {
           this.error(
             DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4038,7 +4038,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isNumericValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4083,7 +4083,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !leftType.isNumericValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4128,7 +4128,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isNumericValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4173,7 +4173,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isNumericValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4218,7 +4218,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isNumericValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4263,7 +4263,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isNumericValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4390,7 +4390,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isIntegerValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4435,7 +4435,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isIntegerValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4480,7 +4480,7 @@ export class Compiler extends DiagnosticEmitter {
         } else {
           rightExpr = this.compileExpression(right, leftType);
           rightType = this.currentType;
-          commonType = Type.commonDenominator(leftType, rightType, false);
+          commonType = Type.commonType(leftType, rightType, contextualType);
           if (!commonType || !commonType.isIntegerValue) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
@@ -4537,8 +4537,21 @@ export class Compiler extends DiagnosticEmitter {
           this.currentType = Type.bool;
 
         } else {
-          rightExpr = this.compileExpression(right, leftType, inheritedConstraints | Constraints.ConvImplicit);
+          rightExpr = this.compileExpression(right, leftType, inheritedConstraints);
           rightType = this.currentType;
+          commonType = Type.commonType(leftType, rightType, contextualType);
+          if (!commonType) {
+            this.error(
+              DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
+              expression.range, "&&", leftType.toString(), rightType.toString()
+            );
+            this.currentType = contextualType;
+            return module.unreachable();
+          }
+          leftExpr = this.convertExpression(leftExpr, leftType, commonType, false, left);
+          leftType = commonType;
+          rightExpr = this.convertExpression(rightExpr, rightType, commonType, false, right);
+          rightType = commonType;
 
           // simplify if copying left is trivial
           if (expr = module.tryCopyTrivialExpression(leftExpr)) {
@@ -4562,7 +4575,7 @@ export class Compiler extends DiagnosticEmitter {
           flow.mergeBranch(rightFlow); // LHS && RHS -> RHS conditionally executes
           flow.noteThen(expr, rightFlow); // LHS && RHS == true -> RHS always executes
           this.currentFlow = flow;
-          this.currentType = leftType;
+          this.currentType = commonType;
         }
         break;
       }
@@ -4603,8 +4616,22 @@ export class Compiler extends DiagnosticEmitter {
           this.currentType = Type.bool;
 
         } else {
-          rightExpr = this.compileExpression(right, leftType, inheritedConstraints | Constraints.ConvImplicit);
+          rightExpr = this.compileExpression(right, leftType, inheritedConstraints);
           rightType = this.currentType;
+          commonType = Type.commonType(leftType, rightType, contextualType);
+          if (!commonType) {
+            this.error(
+              DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
+              expression.range, "||", leftType.toString(), rightType.toString()
+            );
+            this.currentType = contextualType;
+            return module.unreachable();
+          }
+          let possiblyNull = leftType.is(TypeFlags.Nullable) && rightType.is(TypeFlags.Nullable);
+          leftExpr = this.convertExpression(leftExpr, leftType, commonType, false, left);
+          leftType = commonType;
+          rightExpr = this.convertExpression(rightExpr, rightType, commonType, false, right);
+          rightType = commonType;
 
           // simplify if copying left is trivial
           if (expr = module.tryCopyTrivialExpression(leftExpr)) {
@@ -4629,7 +4656,9 @@ export class Compiler extends DiagnosticEmitter {
           flow.mergeBranch(rightFlow); // LHS || RHS -> RHS conditionally executes
           flow.noteElse(expr, rightFlow); // LHS || RHS == false -> RHS always executes
           this.currentFlow = flow;
-          this.currentType = leftType;
+          this.currentType = possiblyNull
+            ? commonType
+            : commonType.nonNullableType;
         }
         break;
       }
@@ -8945,7 +8974,7 @@ export class Compiler extends DiagnosticEmitter {
 
   private compileTernaryExpression(
     expression: TernaryExpression,
-    ctxType: Type,
+    contextualType: Type,
     constraints: Constraints
   ): ExpressionRef {
     let module = this.module;
@@ -8958,24 +8987,24 @@ export class Compiler extends DiagnosticEmitter {
     // FIXME: skips common denominator, inconsistently picking branch type
     let condKind = this.evaluateCondition(condExprTrueish);
     if (condKind == ConditionKind.True) {
-      return module.maybeDropCondition(condExprTrueish, this.compileExpression(ifThen, ctxType));
+      return module.maybeDropCondition(condExprTrueish, this.compileExpression(ifThen, contextualType));
     }
     if (condKind == ConditionKind.False) {
-      return module.maybeDropCondition(condExprTrueish, this.compileExpression(ifElse, ctxType));
+      return module.maybeDropCondition(condExprTrueish, this.compileExpression(ifElse, contextualType));
     }
 
     let outerFlow = this.currentFlow;
     let ifThenFlow = outerFlow.forkThen(condExpr);
     this.currentFlow = ifThenFlow;
-    let ifThenExpr = this.compileExpression(ifThen, ctxType);
+    let ifThenExpr = this.compileExpression(ifThen, contextualType);
     let ifThenType = this.currentType;
 
     let ifElseFlow = outerFlow.forkElse(condExpr);
     this.currentFlow = ifElseFlow;
-    let ifElseExpr = this.compileExpression(ifElse, ctxType == Type.auto ? ifThenType : ctxType);
+    let ifElseExpr = this.compileExpression(ifElse, contextualType == Type.auto ? ifThenType : contextualType);
     let ifElseType = this.currentType;
 
-    if (ctxType == Type.void) { // values, including type mismatch, are irrelevant
+    if (contextualType == Type.void) { // values, including type mismatch, are irrelevant
       if (ifThenType != Type.void) {
         ifThenExpr = module.drop(ifThenExpr);
         ifThenType = Type.void;
@@ -8986,13 +9015,13 @@ export class Compiler extends DiagnosticEmitter {
       }
       this.currentType = Type.void;
     } else {
-      let commonType = Type.commonDenominator(ifThenType, ifElseType, false);
+      let commonType = Type.commonType(ifThenType, ifElseType, contextualType);
       if (!commonType) {
         this.error(
           DiagnosticCode.Type_0_is_not_assignable_to_type_1,
           ifElse.range, ifElseType.toString(), ifThenType.toString()
         );
-        this.currentType = ctxType;
+        this.currentType = contextualType;
         return module.unreachable();
       }
       ifThenExpr = this.convertExpression(ifThenExpr, ifThenType, commonType, false, ifThen);
diff --git a/src/module.ts b/src/module.ts
index 20c05e8130..cad042b46b 100644
--- a/src/module.ts
+++ b/src/module.ts
@@ -128,6 +128,46 @@ export namespace HeapTypeRef {
   export function isSubtype(ht: HeapTypeRef, superHt: HeapTypeRef): bool {
     return binaryen._BinaryenHeapTypeIsSubType(ht, superHt);
   }
+
+  export function leastUpperBound(a: HeapTypeRef, b: HeapTypeRef): HeapTypeRef {
+    // see binaryen/src/wasm/wasm-type.cpp
+    if (a == b) return a;
+    if (getBottom(a) != getBottom(b)) return -1;
+    if (isBottom(a)) return b;
+    if (isBottom(b)) return a;
+    if (a > b) {
+      let t = a;
+      a = b;
+      b = t;
+    }
+    switch (a) {
+      case HeapTypeRef.Extern:
+      case HeapTypeRef.Func: return -1;
+      case HeapTypeRef.Any: return a;
+      case HeapTypeRef.Eq: {
+        return b == HeapTypeRef.I31 || b == HeapTypeRef.Data || b == HeapTypeRef.Array
+          ? HeapTypeRef.Eq
+          : HeapTypeRef.Any;
+      }
+      case HeapTypeRef.I31: {
+        return b == HeapTypeRef.Data || b == HeapTypeRef.Array
+          ? HeapTypeRef.Eq
+          : HeapTypeRef.Any;
+      }
+      case HeapTypeRef.Data: {
+        return b == HeapTypeRef.Array
+          ? HeapTypeRef.Data
+          : HeapTypeRef.Any;
+      }
+      case HeapTypeRef.Array:
+      case HeapTypeRef.String:
+      case HeapTypeRef.StringviewWTF8:
+      case HeapTypeRef.StringviewWTF16:
+      case HeapTypeRef.StringviewIter: return HeapTypeRef.Any;
+    }
+    assert(false);
+    return -1;
+  }
 }
 
 /** Packed array element respectively struct field types. */
diff --git a/src/program.ts b/src/program.ts
index 7ca4cab9f4..ba14333779 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -4415,6 +4415,27 @@ export class Class extends TypedElement {
     registerConcreteElement(program, this);
   }
 
+  /** Computes the least upper bound of two class types. */
+  static leastUpperBound(a: Class, b: Class): Class | null {
+    if (a == b) return a;
+    let candidates = new Set<Class>();
+    candidates.add(a);
+    candidates.add(b);
+    while (true) {
+      let aBase = a.base;
+      let bBase = b.base;
+      if (!aBase && !bBase) return null; // none
+      if (aBase) {
+        if (candidates.has(aBase)) return aBase;
+        candidates.add(a = aBase);
+      }
+      if (bBase) {
+        if (candidates.has(bBase)) return bBase;
+        candidates.add(b = bBase);
+      }
+    }
+  }
+
   /** Sets the base class. */
   setBase(base: Class): void {
     assert(!this.base);
diff --git a/src/resolver.ts b/src/resolver.ts
index 20005b954d..a3abb9d70e 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -83,7 +83,8 @@ import {
   Type,
   Signature,
   typesToString,
-  TypeKind
+  TypeKind,
+  TypeFlags
 } from "./types";
 
 import {
@@ -2070,12 +2071,12 @@ export class Resolver extends DiagnosticEmitter {
         }
         let rightType = this.resolveExpression(right, ctxFlow, leftType, reportMode);
         if (!rightType) return null;
-        let commonType = Type.commonDenominator(leftType, rightType, false);
+        let commonType = Type.commonType(leftType, rightType, ctxType);
         if (!commonType) {
           if (reportMode == ReportMode.Report) {
             this.error(
               DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
-              node.range, leftType.toString(), rightType.toString()
+              node.range, operatorTokenToString(operator), leftType.toString(), rightType.toString()
             );
           }
         }
@@ -2120,7 +2121,7 @@ export class Resolver extends DiagnosticEmitter {
         }
         let rightType = this.resolveExpression(right, ctxFlow, ctxType, reportMode);
         if (!rightType) return null;
-        let commonType = Type.commonDenominator(leftType, rightType, false);
+        let commonType = Type.commonType(leftType, rightType, ctxType);
         if (!commonType || !commonType.isIntegerValue) {
           if (reportMode == ReportMode.Report) {
             this.error(
@@ -2132,11 +2133,43 @@ export class Resolver extends DiagnosticEmitter {
         return commonType;
       }
 
-      // logical: result is LHS (RHS is converted to LHS), not supporting overloads
+      // logical
 
-      case Token.Ampersand_Ampersand:
+      case Token.Ampersand_Ampersand: {
+        let leftType = this.resolveExpression(left, ctxFlow, ctxType, reportMode);
+        if (!leftType) return null;
+        let rightType = this.resolveExpression(right, ctxFlow, leftType, reportMode);
+        if (!rightType) return null;
+        let commonType = Type.commonType(leftType, rightType, ctxType);
+        if (!commonType) {
+          if (reportMode == ReportMode.Report) {
+            this.error(
+              DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
+              node.range, "&&", leftType.toString(), rightType.toString()
+            );
+          }
+        }
+        return commonType;
+      }
       case Token.Bar_Bar: {
-        return this.resolveExpression(left, ctxFlow, ctxType, reportMode);
+        let leftType = this.resolveExpression(left, ctxFlow, ctxType, reportMode);
+        if (!leftType) return null;
+        let rightType = this.resolveExpression(right, ctxFlow, leftType, reportMode);
+        if (!rightType) return null;
+        let commonType = Type.commonType(leftType, rightType, ctxType);
+        if (!commonType) {
+          if (reportMode == ReportMode.Report) {
+            this.error(
+              DiagnosticCode.Operator_0_cannot_be_applied_to_types_1_and_2,
+              node.range, "||", leftType.toString(), rightType.toString()
+            );
+          }
+          return null;
+        }
+        // `LHS || RHS` can only be null if both LHS and RHS are null
+        return leftType.is(TypeFlags.Nullable) && rightType.is(TypeFlags.Nullable)
+          ? commonType
+          : commonType.nonNullableType;
       }
     }
     assert(false);
@@ -2317,7 +2350,7 @@ export class Resolver extends DiagnosticEmitter {
               if (!currentType) return null;
               if (elementType == Type.auto) elementType = currentType;
               else if (currentType != elementType) {
-                let commonType = Type.commonDenominator(elementType, currentType, false);
+                let commonType = Type.commonType(elementType, currentType, elementType);
                 if (commonType) elementType = commonType;
                 // otherwise triggers error on compilation
               }
@@ -2574,7 +2607,7 @@ export class Resolver extends DiagnosticEmitter {
     if (!thenType) return null;
     let elseType = this.resolveExpression(node.ifElse, ctxFlow, thenType, reportMode);
     if (!elseType) return null;
-    let commonType = Type.commonDenominator(thenType, elseType, false);
+    let commonType = Type.commonType(thenType, elseType, ctxType);
     if (!commonType) {
       if (reportMode == ReportMode.Report) {
         this.error(
diff --git a/src/types.ts b/src/types.ts
index 5e22db7ce3..acdf170ce8 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -65,12 +65,12 @@ export const enum TypeKind {
   /** A 128-bit vector. */
   V128,
 
-  // references
+  // references (keep in same order as in Binaryen)
 
-  /** Function reference. */
-  Funcref,
   /** External reference. */
   Externref,
+  /** Function reference. */
+  Funcref,
   /** Any reference. */
   Anyref,
   /** Equatable reference. */
@@ -546,10 +546,40 @@ export class Type {
     return true;
   }
 
-  /** Determines the common denominator type of two types, if there is any. */
-  static commonDenominator(left: Type, right: Type, signednessIsImportant: bool): Type | null {
-    if (right.isAssignableTo(left, signednessIsImportant)) return left;
-    else if (left.isAssignableTo(right, signednessIsImportant)) return right;
+  /** Computes the common type of a binary-like expression, if any. */
+  static commonType(
+    /** LHS type. */
+    left: Type,
+    /** RHS type. */
+    right: Type,
+    /** Contextual type, if any. */
+    contextualType: Type = Type.auto,
+    /** Whether signedness is relevant. */
+    signednessIsRelevant: bool = false
+  ): Type | null {
+    // Compute LUB of internal reference types (classes)
+    if (left.isInternalReference) {
+      if (!right.isInternalReference) return null;
+      // Prefer contextual type if meaningful
+      if (contextualType != Type.void && left.isAssignableTo(contextualType) && right.isAssignableTo(contextualType)) {
+        return contextualType;
+      }
+      let leftClass = left.getClass();
+      let rightClass = right.getClass();
+      if (leftClass && rightClass) {
+        let lubClass = Class.leastUpperBound(leftClass, rightClass);
+        if (lubClass) {
+          let ret = left.is(TypeFlags.Nullable) || right.is(TypeFlags.Nullable) ? lubClass.type.asNullable() : lubClass.type;
+          return ret;
+        }
+      }
+    } else if (right.isInternalReference) {
+      return null;
+    }
+    // TODO: External reference types (needs nullability)
+    // Otherwise do a trivial check
+    if (right.isAssignableTo(left, signednessIsRelevant)) return left;
+    else if (left.isAssignableTo(right, signednessIsRelevant)) return right;
     return null;
   }
 
diff --git a/tests/compiler/logical.debug.wat b/tests/compiler/logical.debug.wat
index ca79a86ba1..9c2b40df28 100644
--- a/tests/compiler/logical.debug.wat
+++ b/tests/compiler/logical.debug.wat
@@ -28,10 +28,12 @@
  (global $~lib/rt/itcms/fromSpace (mut i32) (i32.const 0))
  (global $~lib/rt/tlsf/ROOT (mut i32) (i32.const 0))
  (global $~lib/native/ASC_LOW_MEMORY_LIMIT i32 (i32.const 0))
+ (global $logical/b (mut i32) (i32.const 0))
+ (global $logical/c (mut i32) (i32.const 0))
  (global $~lib/rt/__rtti_base i32 (i32.const 464))
- (global $~lib/memory/__data_end i32 (i32.const 488))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 33256))
- (global $~lib/memory/__heap_base i32 (i32.const 33256))
+ (global $~lib/memory/__data_end i32 (i32.const 500))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 33268))
+ (global $~lib/memory/__heap_base i32 (i32.const 33268))
  (memory $0 1)
  (data (i32.const 12) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\14\00\00\00l\00o\00g\00i\00c\00a\00l\00.\00t\00s\00\00\00\00\00\00\00\00\00")
  (data (i32.const 60) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00(\00\00\00A\00l\00l\00o\00c\00a\00t\00i\00o\00n\00 \00t\00o\00o\00 \00l\00a\00r\00g\00e\00\00\00\00\00")
@@ -42,7 +44,7 @@
  (data (i32.const 316) ",\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s\00\00\00\00\00\00\00\00\00")
  (data (i32.const 368) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
  (data (i32.const 396) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
- (data (i32.const 464) "\05\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00")
+ (data (i32.const 464) "\08\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00 \00\00\00 \00\00\00 \00\00\00")
  (table $0 1 1 funcref)
  (elem $0 (i32.const 1))
  (export "memory" (memory $0))
@@ -2280,54 +2282,40 @@
   end
   return
  )
- (func $~lib/rt/itcms/__collect (type $none_=>_none)
-  i32.const 0
-  drop
-  global.get $~lib/rt/itcms/state
-  i32.const 0
-  i32.gt_s
-  if
-   loop $while-continue|0
-    global.get $~lib/rt/itcms/state
-    i32.const 0
-    i32.ne
-    if
-     call $~lib/rt/itcms/step
-     drop
-     br $while-continue|0
-    end
-   end
+ (func $logical/commonOr (type $i32_=>_i32) (param $b i32) (result i32)
+  local.get $b
+  if (result i32)
+   local.get $b
+  else
+   global.get $logical/c
   end
-  call $~lib/rt/itcms/step
-  drop
-  loop $while-continue|1
-   global.get $~lib/rt/itcms/state
-   i32.const 0
-   i32.ne
-   if
-    call $~lib/rt/itcms/step
-    drop
-    br $while-continue|1
-   end
+  return
+ )
+ (func $logical/commonAnd (type $i32_=>_i32) (param $b i32) (result i32)
+  local.get $b
+  if (result i32)
+   global.get $logical/c
+  else
+   local.get $b
   end
-  global.get $~lib/rt/itcms/total
-  i64.extend_i32_u
-  i32.const 200
-  i64.extend_i32_u
-  i64.mul
-  i64.const 100
-  i64.div_u
-  i32.wrap_i64
-  i32.const 1024
-  i32.add
-  global.set $~lib/rt/itcms/threshold
-  i32.const 0
-  drop
-  i32.const 0
-  drop
+  return
  )
  (func $~lib/rt/__visit_globals (type $i32_=>_none) (param $0 i32)
   (local $1 i32)
+  global.get $logical/b
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
+  global.get $logical/c
+  local.tee $1
+  if
+   local.get $1
+   local.get $0
+   call $~lib/rt/itcms/__visit
+  end
   i32.const 272
   local.get $0
   call $~lib/rt/itcms/__visit
@@ -2354,26 +2342,35 @@
  )
  (func $~lib/rt/__visit_members (type $i32_i32_=>_none) (param $0 i32) (param $1 i32)
   block $invalid
-   block $logical/Obj
-    block $~lib/arraybuffer/ArrayBufferView
-     block $~lib/string/String
-      block $~lib/arraybuffer/ArrayBuffer
-       block $~lib/object/Object
-        local.get $0
-        i32.const 8
-        i32.sub
-        i32.load $0
-        br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $logical/Obj $invalid
+   block $logical/C
+    block $logical/A
+     block $logical/B
+      block $logical/Obj
+       block $~lib/arraybuffer/ArrayBufferView
+        block $~lib/string/String
+         block $~lib/arraybuffer/ArrayBuffer
+          block $~lib/object/Object
+           local.get $0
+           i32.const 8
+           i32.sub
+           i32.load $0
+           br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $logical/Obj $logical/B $logical/A $logical/C $invalid
+          end
+          return
+         end
+         return
+        end
+        return
        end
+       local.get $0
+       local.get $1
+       call $~lib/arraybuffer/ArrayBufferView~visit
        return
       end
       return
      end
      return
     end
-    local.get $0
-    local.get $1
-    call $~lib/arraybuffer/ArrayBufferView~visit
     return
    end
    return
@@ -2388,8 +2385,8 @@
   global.get $~lib/memory/__data_end
   i32.lt_s
   if
-   i32.const 33280
-   i32.const 33328
+   i32.const 33296
+   i32.const 33344
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
@@ -2434,6 +2431,120 @@
   global.set $~lib/memory/__stack_pointer
   local.get $1
  )
+ (func $logical/A#constructor (type $i32_=>_i32) (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i64.const 0
+  i64.store $0
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 6
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store $0 offset=4
+  local.get $1
+  call $~lib/object/Object#constructor
+  local.tee $this
+  i32.store $0
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
+ (func $logical/B#constructor (type $i32_=>_i32) (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i64.const 0
+  i64.store $0
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 5
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store $0 offset=4
+  local.get $1
+  call $logical/A#constructor
+  local.tee $this
+  i32.store $0
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
+ (func $logical/C#constructor (type $i32_=>_i32) (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i64.const 0
+  i64.store $0
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 7
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store $0
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store $0 offset=4
+  local.get $1
+  call $logical/A#constructor
+  local.tee $this
+  i32.store $0
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
  (func $start:logical (type $none_=>_none)
   (local $0 f32)
   (local $1 f32)
@@ -2979,9 +3090,74 @@
    call $~lib/builtins/abort
    unreachable
   end
-  global.get $~lib/memory/__heap_base
-  global.set $~lib/memory/__stack_pointer
-  call $~lib/rt/itcms/__collect
+  i32.const 0
+  call $logical/B#constructor
+  global.set $logical/b
+  i32.const 0
+  call $logical/C#constructor
+  global.set $logical/c
+  global.get $logical/b
+  local.set $4
+  global.get $~lib/memory/__stack_pointer
+  local.get $4
+  i32.store $0
+  local.get $4
+  call $logical/commonOr
+  global.get $logical/b
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 106
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  call $logical/commonOr
+  global.get $logical/c
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 107
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $logical/b
+  local.set $4
+  global.get $~lib/memory/__stack_pointer
+  local.get $4
+  i32.store $0
+  local.get $4
+  call $logical/commonAnd
+  global.get $logical/c
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 112
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  call $logical/commonAnd
+  i32.const 0
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 113
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
   global.get $~lib/memory/__stack_pointer
   i32.const 4
   i32.add
diff --git a/tests/compiler/logical.json b/tests/compiler/logical.json
index b83788465e..1bdd02b1be 100644
--- a/tests/compiler/logical.json
+++ b/tests/compiler/logical.json
@@ -1,5 +1,4 @@
 {
   "asc_flags": [
-  ],
-  "asc_rtrace": true
+  ]
 }
diff --git a/tests/compiler/logical.release.wat b/tests/compiler/logical.release.wat
index 9dcaebeb19..704df6e73f 100644
--- a/tests/compiler/logical.release.wat
+++ b/tests/compiler/logical.release.wat
@@ -1,9 +1,9 @@
 (module
+ (type $i32_=>_i32 (func_subtype (param i32) (result i32) func))
  (type $none_=>_none (func_subtype func))
  (type $i32_=>_none (func_subtype (param i32) func))
  (type $i32_i32_=>_none (func_subtype (param i32 i32) func))
  (type $none_=>_i32 (func_subtype (result i32) func))
- (type $i32_=>_i32 (func_subtype (param i32) (result i32) func))
  (type $i32_i32_i32_i32_=>_none (func_subtype (param i32 i32 i32 i32) func))
  (type $i32_i32_i32_=>_none (func_subtype (param i32 i32 i32) func))
  (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
@@ -17,7 +17,9 @@
  (global $~lib/rt/itcms/white (mut i32) (i32.const 0))
  (global $~lib/rt/itcms/fromSpace (mut i32) (i32.const 0))
  (global $~lib/rt/tlsf/ROOT (mut i32) (i32.const 0))
- (global $~lib/memory/__stack_pointer (mut i32) (i32.const 34280))
+ (global $logical/b (mut i32) (i32.const 0))
+ (global $logical/c (mut i32) (i32.const 0))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 34292))
  (memory $0 1)
  (data (i32.const 1036) ",")
  (data (i32.const 1048) "\02\00\00\00\14\00\00\00l\00o\00g\00i\00c\00a\00l\00.\00t\00s")
@@ -31,12 +33,24 @@
  (data (i32.const 1352) "\02\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s")
  (data (i32.const 1420) "<")
  (data (i32.const 1432) "\02\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s")
- (data (i32.const 1488) "\05\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 ")
+ (data (i32.const 1488) "\08\00\00\00 \00\00\00 \00\00\00 \00\00\00\00\00\00\00 \00\00\00 \00\00\00 \00\00\00 ")
  (export "memory" (memory $0))
  (start $~start)
  (func $~lib/rt/itcms/visitRoots (type $none_=>_none)
   (local $0 i32)
   (local $1 i32)
+  global.get $logical/b
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
+  global.get $logical/c
+  local.tee $0
+  if
+   local.get $0
+   call $byn-split-outlined-A$~lib/rt/itcms/__visit
+  end
   i32.const 1296
   call $byn-split-outlined-A$~lib/rt/itcms/__visit
   i32.const 1104
@@ -114,7 +128,7 @@
     i32.load $0 offset=8
     i32.eqz
     local.get $0
-    i32.const 34280
+    i32.const 34292
     i32.lt_u
     i32.and
     i32.eqz
@@ -742,10 +756,10 @@
   if
    unreachable
   end
-  i32.const 34288
+  i32.const 34304
   i32.const 0
   i32.store $0
-  i32.const 35856
+  i32.const 35872
   i32.const 0
   i32.store $0
   loop $for-loop|0
@@ -756,7 +770,7 @@
     local.get $0
     i32.const 2
     i32.shl
-    i32.const 34288
+    i32.const 34304
     i32.add
     i32.const 0
     i32.store $0 offset=4
@@ -774,7 +788,7 @@
       i32.add
       i32.const 2
       i32.shl
-      i32.const 34288
+      i32.const 34304
       i32.add
       i32.const 0
       i32.store $0 offset=96
@@ -792,13 +806,13 @@
     br $for-loop|0
    end
   end
-  i32.const 34288
-  i32.const 35860
+  i32.const 34304
+  i32.const 35876
   memory.size $0
   i32.const 16
   i32.shl
   call $~lib/rt/tlsf/addMemory
-  i32.const 34288
+  i32.const 34304
   global.set $~lib/rt/tlsf/ROOT
  )
  (func $~lib/rt/itcms/step (type $none_=>_i32) (result i32)
@@ -883,7 +897,7 @@
      local.set $0
      loop $while-continue|0
       local.get $0
-      i32.const 34280
+      i32.const 34292
       i32.lt_u
       if
        local.get $0
@@ -983,7 +997,7 @@
      unreachable
     end
     local.get $0
-    i32.const 34280
+    i32.const 34292
     i32.lt_u
     if
      local.get $0
@@ -1006,7 +1020,7 @@
      i32.const 4
      i32.add
      local.tee $0
-     i32.const 34280
+     i32.const 34292
      i32.ge_u
      if
       global.get $~lib/rt/tlsf/ROOT
@@ -1360,16 +1374,32 @@
  )
  (func $~lib/rt/__visit_members (type $i32_=>_none) (param $0 i32)
   block $invalid
-   block $logical/Obj
-    block $~lib/arraybuffer/ArrayBufferView
-     block $~lib/string/String
-      block $~lib/arraybuffer/ArrayBuffer
-       block $~lib/object/Object
+   block $logical/C
+    block $logical/A
+     block $logical/B
+      block $logical/Obj
+       block $~lib/arraybuffer/ArrayBufferView
+        block $~lib/string/String
+         block $~lib/arraybuffer/ArrayBuffer
+          block $~lib/object/Object
+           local.get $0
+           i32.const 8
+           i32.sub
+           i32.load $0
+           br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $logical/Obj $logical/B $logical/A $logical/C $invalid
+          end
+          return
+         end
+         return
+        end
+        return
+       end
+       local.get $0
+       i32.load $0
+       local.tee $0
+       if
         local.get $0
-        i32.const 8
-        i32.sub
-        i32.load $0
-        br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $logical/Obj $invalid
+        call $byn-split-outlined-A$~lib/rt/itcms/__visit
        end
        return
       end
@@ -1377,13 +1407,6 @@
      end
      return
     end
-    local.get $0
-    i32.load $0
-    local.tee $0
-    if
-     local.get $0
-     call $byn-split-outlined-A$~lib/rt/itcms/__visit
-    end
     return
    end
    return
@@ -1392,191 +1415,316 @@
  )
  (func $~start (type $none_=>_none)
   (local $0 i32)
+  (local $1 i32)
+  block $__inlined_func$start:logical
+   global.get $~lib/memory/__stack_pointer
+   i32.const 4
+   i32.sub
+   global.set $~lib/memory/__stack_pointer
+   block $folding-inner0
+    global.get $~lib/memory/__stack_pointer
+    i32.const 1524
+    i32.lt_s
+    br_if $folding-inner0
+    global.get $~lib/memory/__stack_pointer
+    i32.const 0
+    i32.store $0
+    memory.size $0
+    i32.const 16
+    i32.shl
+    i32.const 34292
+    i32.sub
+    i32.const 1
+    i32.shr_u
+    global.set $~lib/rt/itcms/threshold
+    i32.const 1220
+    i32.const 1216
+    i32.store $0
+    i32.const 1224
+    i32.const 1216
+    i32.store $0
+    i32.const 1216
+    global.set $~lib/rt/itcms/pinSpace
+    i32.const 1252
+    i32.const 1248
+    i32.store $0
+    i32.const 1256
+    i32.const 1248
+    i32.store $0
+    i32.const 1248
+    global.set $~lib/rt/itcms/toSpace
+    i32.const 1396
+    i32.const 1392
+    i32.store $0
+    i32.const 1400
+    i32.const 1392
+    i32.store $0
+    i32.const 1392
+    global.set $~lib/rt/itcms/fromSpace
+    call $logical/Obj#constructor
+    local.set $0
+    global.get $~lib/memory/__stack_pointer
+    local.get $0
+    i32.store $0
+    local.get $0
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 1056
+     i32.const 87
+     i32.const 1
+     call $~lib/builtins/abort
+     unreachable
+    end
+    call $logical/Obj#constructor
+    local.set $0
+    global.get $~lib/memory/__stack_pointer
+    local.get $0
+    i32.store $0
+    local.get $0
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 1056
+     i32.const 92
+     i32.const 1
+     call $~lib/builtins/abort
+     unreachable
+    end
+    global.get $~lib/memory/__stack_pointer
+    i32.const 8
+    i32.sub
+    global.set $~lib/memory/__stack_pointer
+    global.get $~lib/memory/__stack_pointer
+    i32.const 1524
+    i32.lt_s
+    br_if $folding-inner0
+    global.get $~lib/memory/__stack_pointer
+    local.tee $0
+    i64.const 0
+    i64.store $0
+    local.get $0
+    i32.const 5
+    call $~lib/rt/itcms/__new
+    local.tee $0
+    i32.store $0
+    global.get $~lib/memory/__stack_pointer
+    local.tee $1
+    local.get $0
+    i32.store $0 offset=4
+    local.get $1
+    local.get $0
+    call $logical/A#constructor
+    local.tee $0
+    i32.store $0
+    global.get $~lib/memory/__stack_pointer
+    i32.const 8
+    i32.add
+    global.set $~lib/memory/__stack_pointer
+    local.get $0
+    global.set $logical/b
+    global.get $~lib/memory/__stack_pointer
+    i32.const 8
+    i32.sub
+    global.set $~lib/memory/__stack_pointer
+    global.get $~lib/memory/__stack_pointer
+    i32.const 1524
+    i32.lt_s
+    br_if $folding-inner0
+    global.get $~lib/memory/__stack_pointer
+    local.tee $0
+    i64.const 0
+    i64.store $0
+    local.get $0
+    i32.const 7
+    call $~lib/rt/itcms/__new
+    local.tee $0
+    i32.store $0
+    global.get $~lib/memory/__stack_pointer
+    local.tee $1
+    local.get $0
+    i32.store $0 offset=4
+    local.get $1
+    local.get $0
+    call $logical/A#constructor
+    local.tee $0
+    i32.store $0
+    global.get $~lib/memory/__stack_pointer
+    i32.const 8
+    i32.add
+    global.set $~lib/memory/__stack_pointer
+    local.get $0
+    global.set $logical/c
+    global.get $~lib/memory/__stack_pointer
+    global.get $logical/b
+    local.tee $0
+    i32.store $0
+    local.get $0
+    local.get $0
+    global.get $logical/c
+    local.get $0
+    select
+    i32.ne
+    if
+     i32.const 0
+     i32.const 1056
+     i32.const 106
+     i32.const 1
+     call $~lib/builtins/abort
+     unreachable
+    end
+    global.get $~lib/memory/__stack_pointer
+    global.get $logical/b
+    local.tee $0
+    i32.store $0
+    global.get $logical/c
+    local.tee $1
+    local.get $0
+    local.get $0
+    select
+    local.get $1
+    i32.ne
+    if
+     i32.const 0
+     i32.const 1056
+     i32.const 112
+     i32.const 1
+     call $~lib/builtins/abort
+     unreachable
+    end
+    global.get $~lib/memory/__stack_pointer
+    i32.const 4
+    i32.add
+    global.set $~lib/memory/__stack_pointer
+    br $__inlined_func$start:logical
+   end
+   i32.const 34320
+   i32.const 34368
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $logical/Obj#constructor (type $none_=>_i32) (result i32)
+  (local $0 i32)
+  (local $1 i32)
   global.get $~lib/memory/__stack_pointer
-  i32.const 4
+  i32.const 8
   i32.sub
   global.set $~lib/memory/__stack_pointer
   global.get $~lib/memory/__stack_pointer
-  i32.const 1512
+  i32.const 1524
   i32.lt_s
   if
-   i32.const 34304
-   i32.const 34352
+   i32.const 34320
+   i32.const 34368
    i32.const 1
    i32.const 1
    call $~lib/builtins/abort
    unreachable
   end
   global.get $~lib/memory/__stack_pointer
-  i32.const 0
-  i32.store $0
-  memory.size $0
-  i32.const 16
-  i32.shl
-  i32.const 34280
-  i32.sub
-  i32.const 1
-  i32.shr_u
-  global.set $~lib/rt/itcms/threshold
-  i32.const 1220
-  i32.const 1216
-  i32.store $0
-  i32.const 1224
-  i32.const 1216
-  i32.store $0
-  i32.const 1216
-  global.set $~lib/rt/itcms/pinSpace
-  i32.const 1252
-  i32.const 1248
-  i32.store $0
-  i32.const 1256
-  i32.const 1248
-  i32.store $0
-  i32.const 1248
-  global.set $~lib/rt/itcms/toSpace
-  i32.const 1396
-  i32.const 1392
-  i32.store $0
-  i32.const 1400
-  i32.const 1392
+  local.tee $0
+  i64.const 0
+  i64.store $0
+  local.get $0
+  i32.const 4
+  call $~lib/rt/itcms/__new
+  local.tee $0
   i32.store $0
-  i32.const 1392
-  global.set $~lib/rt/itcms/fromSpace
-  call $logical/Obj#constructor
-  local.set $0
   global.get $~lib/memory/__stack_pointer
+  local.tee $1
+  local.get $0
+  i32.store $0 offset=4
+  local.get $1
   local.get $0
+  call $~lib/object/Object#constructor
+  local.tee $0
   i32.store $0
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.add
+  global.set $~lib/memory/__stack_pointer
   local.get $0
-  i32.eqz
+ )
+ (func $logical/A#constructor (type $i32_=>_i32) (param $0 i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1524
+  i32.lt_s
   if
-   i32.const 0
-   i32.const 1056
-   i32.const 87
+   i32.const 34320
+   i32.const 34368
+   i32.const 1
    i32.const 1
    call $~lib/builtins/abort
    unreachable
   end
-  call $logical/Obj#constructor
-  local.set $0
   global.get $~lib/memory/__stack_pointer
-  local.get $0
-  i32.store $0
+  i64.const 0
+  i64.store $0
   local.get $0
   i32.eqz
   if
-   i32.const 0
-   i32.const 1056
-   i32.const 92
-   i32.const 1
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i32.const 34280
-  global.set $~lib/memory/__stack_pointer
-  global.get $~lib/rt/itcms/state
-  i32.const 0
-  i32.gt_s
-  if
-   loop $while-continue|0
-    global.get $~lib/rt/itcms/state
-    if
-     call $~lib/rt/itcms/step
-     drop
-     br $while-continue|0
-    end
-   end
-  end
-  call $~lib/rt/itcms/step
-  drop
-  loop $while-continue|1
-   global.get $~lib/rt/itcms/state
-   if
-    call $~lib/rt/itcms/step
-    drop
-    br $while-continue|1
-   end
+   global.get $~lib/memory/__stack_pointer
+   i32.const 6
+   call $~lib/rt/itcms/__new
+   local.tee $0
+   i32.store $0
   end
-  global.get $~lib/rt/itcms/total
-  i64.extend_i32_u
-  i64.const 200
-  i64.mul
-  i64.const 100
-  i64.div_u
-  i32.wrap_i64
-  i32.const 1024
-  i32.add
-  global.set $~lib/rt/itcms/threshold
   global.get $~lib/memory/__stack_pointer
-  i32.const 4
+  local.tee $1
+  local.get $0
+  i32.store $0 offset=4
+  local.get $1
+  local.get $0
+  call $~lib/object/Object#constructor
+  local.tee $0
+  i32.store $0
+  global.get $~lib/memory/__stack_pointer
+  i32.const 8
   i32.add
   global.set $~lib/memory/__stack_pointer
+  local.get $0
  )
- (func $logical/Obj#constructor (type $none_=>_i32) (result i32)
-  (local $0 i32)
-  (local $1 i32)
+ (func $~lib/object/Object#constructor (type $i32_=>_i32) (param $0 i32) (result i32)
   global.get $~lib/memory/__stack_pointer
-  i32.const 8
+  i32.const 4
   i32.sub
   global.set $~lib/memory/__stack_pointer
-  block $folding-inner0
-   global.get $~lib/memory/__stack_pointer
-   i32.const 1512
-   i32.lt_s
-   br_if $folding-inner0
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1524
+  i32.lt_s
+  if
+   i32.const 34320
+   i32.const 34368
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store $0
+  local.get $0
+  i32.eqz
+  if
    global.get $~lib/memory/__stack_pointer
-   local.tee $0
-   i64.const 0
-   i64.store $0
-   local.get $0
-   i32.const 4
+   i32.const 0
    call $~lib/rt/itcms/__new
    local.tee $0
    i32.store $0
-   global.get $~lib/memory/__stack_pointer
-   local.tee $1
-   local.get $0
-   i32.store $0 offset=4
-   local.get $1
-   i32.const 4
-   i32.sub
-   global.set $~lib/memory/__stack_pointer
-   global.get $~lib/memory/__stack_pointer
-   i32.const 1512
-   i32.lt_s
-   br_if $folding-inner0
-   global.get $~lib/memory/__stack_pointer
-   i32.const 0
-   i32.store $0
-   local.get $0
-   i32.eqz
-   if
-    global.get $~lib/memory/__stack_pointer
-    i32.const 0
-    call $~lib/rt/itcms/__new
-    local.tee $0
-    i32.store $0
-   end
-   global.get $~lib/memory/__stack_pointer
-   i32.const 4
-   i32.add
-   global.set $~lib/memory/__stack_pointer
-   local.get $1
-   local.get $0
-   i32.store $0
-   global.get $~lib/memory/__stack_pointer
-   i32.const 8
-   i32.add
-   global.set $~lib/memory/__stack_pointer
-   local.get $0
-   return
   end
-  i32.const 34304
-  i32.const 34352
-  i32.const 1
-  i32.const 1
-  call $~lib/builtins/abort
-  unreachable
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $0
  )
  (func $byn-split-outlined-A$~lib/rt/itcms/__visit (type $i32_=>_none) (param $0 i32)
   global.get $~lib/rt/itcms/white
diff --git a/tests/compiler/logical.ts b/tests/compiler/logical.ts
index cad6dbed6e..62a26f9d66 100644
--- a/tests/compiler/logical.ts
+++ b/tests/compiler/logical.ts
@@ -91,5 +91,23 @@ function testContextualBoolOr(someObj: Obj, someInt: i32): bool {
 }
 assert(testContextualBoolOr(new Obj(), 0));
 
-__stack_pointer = __heap_base;
-__collect();
+// Common type
+
+class A {}
+class B extends A {}
+class C extends A {}
+
+let b = new B();
+let c = new C();
+
+function commonOr(b: B | null): A {
+  return b || c;
+}
+assert(commonOr(b) == b);
+assert(commonOr(null) == c);
+
+function commonAnd(b: B | null): A | null {
+  return b && c;
+}
+assert(commonAnd(b) == c);
+assert(commonAnd(null) == null);