diff --git a/src/compiler.ts b/src/compiler.ts
index 7e4c3c9c40..3ab0e76b40 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -223,6 +223,8 @@ import {
   lowerRequiresExportRuntime
 } from "./bindings/js";
 
+import * as binaryen from "./glue/binaryen";
+
 /** Features enabled by default. */
 export const defaultFeatures = Feature.MutableGlobals
                              | Feature.SignExtension
@@ -375,7 +377,9 @@ export const enum Constraints {
   /** Indicates that static data is preferred. */
   PreferStatic = 1 << 4,
   /** Indicates that the value will become `this` of a property access or instance call. */
-  IsThis = 1 << 5
+  IsThis = 1 << 5,
+  /** Indicates that the expression is compiled for an immediate return position. */
+  WillReturn = 1 << 6
 }
 
 /** Runtime features to be activated by the compiler. */
@@ -2825,6 +2829,7 @@ export class Compiler extends DiagnosticEmitter {
     if (valueExpression) {
       let constraints = Constraints.ConvImplicit;
       if (flow.sourceFunction.is(CommonFlags.ModuleExport)) constraints |= Constraints.MustWrap;
+      if (!flow.isInline && this.options.hasFeature(Feature.TailCalls)) constraints |= Constraints.WillReturn;
 
       expr = this.compileExpression(valueExpression, returnType, constraints);
       if (!flow.canOverflow(expr, returnType)) flow.set(FlowFlags.ReturnsWrapped);
@@ -2854,6 +2859,8 @@ export class Compiler extends DiagnosticEmitter {
         : module.br(inlineReturnLabel);
     }
 
+    if (expr && this.options.hasFeature(Feature.TailCalls) && this.isTailReturnCallExpression(expr)) return expr;
+
     // Otherwise emit a normal return
     return expr
       ? this.currentType == Type.void
@@ -6145,6 +6152,7 @@ export class Compiler extends DiagnosticEmitter {
             Constraints.ConvImplicit | Constraints.IsThis
           );
         }
+        if (!this.canTailReturn(constraints, contextualType, functionInstance.signature.returnType))  constraints &= ~Constraints.WillReturn;
         return this.compileCallDirect(
           functionInstance,
           expression.args,
@@ -6159,13 +6167,15 @@ export class Compiler extends DiagnosticEmitter {
     let functionArg = this.compileExpression(expression.expression, Type.auto);
     let signature = this.currentType.getSignature();
     if (signature) {
+      if (!this.canTailReturn(constraints, contextualType, signature.returnType)) constraints &= ~Constraints.WillReturn;
       return this.compileCallIndirect(
         signature,
         functionArg,
         expression.args,
         expression,
         0,
-        contextualType == Type.void
+        contextualType == Type.void,
+        constraints
       );
     }
     this.error(
@@ -6184,6 +6194,38 @@ export class Compiler extends DiagnosticEmitter {
     return module.unreachable();
   }
 
+  private canTailReturn(constraints: Constraints, contextType: Type, returnType: Type): bool {
+    if ((constraints & Constraints.WillReturn) == 0) return false;
+    // Tail calls are only valid as long as no result conversions are needed.
+    // `compileExpression` skips conversion for:
+    // 1. `currentType == nonnull<contextType>`, and
+    // 2. nullable reference identity (`T | null` -> `T | null`) where conversion is a no-op.
+    let sameWithoutNullable = returnType.equals(contextType.nonNullableType);
+    let sameNullableRef = returnType.isReference && returnType.equals(contextType);
+    if (!sameWithoutNullable && !sameNullableRef) return false;
+    if ((constraints & Constraints.MustWrap) == 0) return true;
+    switch (returnType.kind) {
+      case TypeKind.I8:
+      case TypeKind.I16:
+      case TypeKind.U8:
+      case TypeKind.U16:
+        return false;
+      default:
+        return true;
+    }
+  }
+
+  private isTailReturnCallExpression(expr: ExpressionRef): bool {
+    switch (getExpressionId(expr)) {
+      case ExpressionId.Call:
+        return binaryen._BinaryenCallIsReturn(expr);
+      case ExpressionId.CallIndirect:
+        return binaryen._BinaryenCallIndirectIsReturn(expr);
+      default:
+        return false;
+    }
+  }
+
   /** Compiles the given arguments like a call expression according to the specified context. */
   private compileCallExpressionLike(
     /** Called expression. */
@@ -6439,7 +6481,7 @@ export class Compiler extends DiagnosticEmitter {
       operands[index] = paramExpr;
     }
     assert(index == numArgumentsInclThis);
-    return this.makeCallDirect(instance, operands, reportNode, (constraints & Constraints.WillDrop) != 0);
+    return this.makeCallDirect(instance, operands, reportNode, (constraints & Constraints.WillDrop) != 0, (constraints & Constraints.WillReturn) != 0);
   }
 
   makeCallInline(
@@ -6883,7 +6925,8 @@ export class Compiler extends DiagnosticEmitter {
     instance: Function,
     operands: ExpressionRef[] | null,
     reportNode: Node,
-    immediatelyDropped: bool = false
+    immediatelyDropped: bool = false,
+    isReturn: bool = false
   ): ExpressionRef {
     if (instance.hasDecorator(DecoratorFlags.Inline)) {
       if (!instance.is(CommonFlags.Overridden)) {
@@ -6982,8 +7025,10 @@ export class Compiler extends DiagnosticEmitter {
           lastOperand
         ], lastOperandType.toRef());
         this.operandsTostack(instance.signature, operands);
-        let expr = module.call(instance.internalName, operands, returnTypeRef);
-        if (returnType != Type.void && immediatelyDropped) {
+        let expr = isReturn
+          ? module.return_call(instance.internalName, operands, returnTypeRef)
+          : module.call(instance.internalName, operands, returnTypeRef);
+        if (!isReturn && returnType != Type.void && immediatelyDropped) {
           expr = module.drop(expr);
           this.currentType = Type.void;
         } else {
@@ -6999,7 +7044,9 @@ export class Compiler extends DiagnosticEmitter {
     }
 
     if (operands) this.operandsTostack(instance.signature, operands);
-    let expr = module.call(instance.internalName, operands, returnType.toRef());
+    let expr = isReturn
+      ? module.return_call(instance.internalName, operands, returnType.toRef())
+      : module.call(instance.internalName, operands, returnType.toRef());
     this.currentType = returnType;
     return expr;
   }
@@ -7011,7 +7058,8 @@ export class Compiler extends DiagnosticEmitter {
     argumentExpressions: Expression[],
     reportNode: Node,
     thisArg: ExpressionRef = 0,
-    immediatelyDropped: bool = false
+    immediatelyDropped: bool = false,
+    constraints: Constraints = Constraints.None
   ): ExpressionRef {
     let numArguments = argumentExpressions.length;
 
@@ -7041,7 +7089,7 @@ export class Compiler extends DiagnosticEmitter {
       );
     }
     assert(index == numArgumentsInclThis);
-    return this.makeCallIndirect(signature, functionArg, reportNode, operands, immediatelyDropped);
+    return this.makeCallIndirect(signature, functionArg, reportNode, operands, immediatelyDropped, (constraints & Constraints.WillReturn) != 0);
   }
 
   /** Creates an indirect call to a first-class function. */
@@ -7051,6 +7099,7 @@ export class Compiler extends DiagnosticEmitter {
     reportNode: Node,
     operands: ExpressionRef[] | null = null,
     immediatelyDropped: bool = false,
+    isReturn: bool = false,
   ): ExpressionRef {
     let module = this.module;
     let numOperands = operands ? operands.length : 0;
@@ -7101,13 +7150,21 @@ export class Compiler extends DiagnosticEmitter {
       ], sizeTypeRef);
     }
     if (operands) this.operandsTostack(signature, operands);
-    let expr = module.call_indirect(
-      null, // TODO: handle multiple tables
-      module.load(4, false, functionArg, TypeRef.I32), // ._index
-      operands,
-      signature.paramRefs,
-      signature.resultRefs
-    );
+    let expr = isReturn
+      ? module.return_call_indirect(
+          null,
+          module.load(4, false, functionArg, TypeRef.I32),
+          operands,
+          signature.paramRefs,
+          signature.resultRefs
+        )
+      : module.call_indirect(
+          null,
+          module.load(4, false, functionArg, TypeRef.I32),
+          operands,
+          signature.paramRefs,
+          signature.resultRefs
+        );
     this.currentType = returnType;
     return expr;
   }
diff --git a/src/module.ts b/src/module.ts
index 2719f60c50..67256396ea 100644
--- a/src/module.ts
+++ b/src/module.ts
@@ -1842,21 +1842,16 @@ export class Module {
     index: ExpressionRef,
     operands: ExpressionRef[] | null,
     params: TypeRef,
-    results: TypeRef,
-    isReturn: bool = false
+    results: TypeRef
   ): ExpressionRef {
     let cStr = this.allocStringCached(tableName != null
       ? tableName
       : CommonNames.DefaultTable
     );
     let cArr = allocPtrArray(operands);
-    let ret = isReturn
-      ? binaryen._BinaryenReturnCallIndirect(
-          this.ref, cStr, index, cArr, operands ? operands.length : 0, params, results
-        )
-      : binaryen._BinaryenCallIndirect(
-          this.ref, cStr, index, cArr, operands ? operands.length : 0, params, results
-        );
+    let ret = binaryen._BinaryenCallIndirect(
+      this.ref, cStr, index, cArr, operands ? operands.length : 0, params, results
+    );
     binaryen._free(cArr);
     return ret;
   }
@@ -1868,7 +1863,13 @@ export class Module {
     params: TypeRef,
     results: TypeRef
   ): ExpressionRef {
-    return this.call_indirect(tableName, index, operands, params, results, true);
+    let cStr = this.allocStringCached(tableName != null ? tableName : CommonNames.DefaultTable);
+    let cArr = allocPtrArray(operands);
+    let ret = binaryen._BinaryenReturnCallIndirect(
+      this.ref, cStr, index, cArr, operands ? operands.length : 0, params, results
+    );
+    binaryen._free(cArr);
+    return ret;
   }
 
   unreachable(): ExpressionRef {
diff --git a/tests/compiler/features/tail-calls.debug.wat b/tests/compiler/features/tail-calls.debug.wat
new file mode 100644
index 0000000000..76dc282b99
--- /dev/null
+++ b/tests/compiler/features/tail-calls.debug.wat
@@ -0,0 +1,2607 @@
+(module
+ (type $0 (func (param i32) (result i32)))
+ (type $1 (func (param i32 i32)))
+ (type $2 (func (param i32)))
+ (type $3 (func))
+ (type $4 (func (param i32 i32) (result i32)))
+ (type $5 (func (param i32) (result i64)))
+ (type $6 (func (param i32 i32 i32)))
+ (type $7 (func (param i32 i32) (result i64)))
+ (type $8 (func (param i32 i32 i32 i32)))
+ (type $9 (func (param i32 i32 i64) (result i32)))
+ (type $10 (func (result i32)))
+ (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
+ (global $~argumentsLength (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/total (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/threshold (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/state (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/visitCount (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/pinSpace (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/iter (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/toSpace (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/white (mut i32) (i32.const 0))
+ (global $~lib/shared/runtime/Runtime.Stub i32 (i32.const 0))
+ (global $~lib/shared/runtime/Runtime.Minimal i32 (i32.const 1))
+ (global $~lib/shared/runtime/Runtime.Incremental i32 (i32.const 2))
+ (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 $~lib/rt/__rtti_base i32 (i32.const 480))
+ (global $~lib/memory/__data_end i32 (i32.const 512))
+ (global $~lib/memory/__stack_pointer (mut i32) (i32.const 33280))
+ (global $~lib/memory/__heap_base i32 (i32.const 33280))
+ (memory $0 1)
+ (data $0 (i32.const 12) "\1c\00\00\00\00\00\00\00\00\00\00\00\04\00\00\00\08\00\00\00\01\00\00\00\00\00\00\00\00\00\00\00")
+ (data $1 (i32.const 44) "<\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")
+ (data $2 (i32.const 108) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00 \00\00\00~\00l\00i\00b\00/\00r\00t\00/\00i\00t\00c\00m\00s\00.\00t\00s\00\00\00\00\00\00\00\00\00\00\00\00\00")
+ (data $3 (i32.const 176) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
+ (data $4 (i32.const 208) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
+ (data $5 (i32.const 236) "<\00\00\00\00\00\00\00\00\00\00\00\02\00\00\00$\00\00\00I\00n\00d\00e\00x\00 \00o\00u\00t\00 \00o\00f\00 \00r\00a\00n\00g\00e\00\00\00\00\00\00\00\00\00")
+ (data $6 (i32.const 300) ",\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 $7 (i32.const 352) "\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00")
+ (data $8 (i32.const 380) "<\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 $9 (i32.const 444) "\1c\00\00\00\00\00\00\00\00\00\00\00\06\00\00\00\08\00\00\00\02\00\00\00\00\00\00\00\00\00\00\00")
+ (data $10 (i32.const 480) "\07\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 3 3 funcref)
+ (elem $0 (i32.const 1) $features/tail-calls/inc $features/tail-calls/maybeBox)
+ (export "direct" (func $features/tail-calls/direct))
+ (export "directVoid" (func $features/tail-calls/directVoid))
+ (export "indirect" (func $features/tail-calls/indirect))
+ (export "converted" (func $features/tail-calls/converted))
+ (export "convertedIndirect" (func $features/tail-calls/convertedIndirect))
+ (export "nullable" (func $features/tail-calls/nullable))
+ (export "nullableIndirect" (func $features/tail-calls/nullableIndirect))
+ (export "memory" (memory $0))
+ (start $~start)
+ (func $features/tail-calls/inc (param $x i32) (result i32)
+  local.get $x
+  i32.const 1
+  i32.add
+  return
+ )
+ (func $features/tail-calls/direct (param $x i32) (result i32)
+  local.get $x
+  return_call $features/tail-calls/inc
+ )
+ (func $features/tail-calls/noop
+ )
+ (func $features/tail-calls/directVoid
+  return_call $features/tail-calls/noop
+ )
+ (func $features/tail-calls/invoke (param $fn i32) (param $x i32) (result i32)
+  local.get $x
+  i32.const 1
+  global.set $~argumentsLength
+  local.get $fn
+  i32.load
+  return_call_indirect (type $0)
+ )
+ (func $features/tail-calls/converted (param $x i32) (result i64)
+  local.get $x
+  call $features/tail-calls/inc
+  i64.extend_i32_s
+  return
+ )
+ (func $features/tail-calls/widenInvoke (param $fn i32) (param $x i32) (result i64)
+  local.get $x
+  i32.const 1
+  global.set $~argumentsLength
+  local.get $fn
+  i32.load
+  call_indirect (type $0)
+  i64.extend_i32_s
+  return
+ )
+ (func $~lib/rt/itcms/Object#set:nextWithColor (param $this i32) (param $nextWithColor i32)
+  local.get $this
+  local.get $nextWithColor
+  i32.store offset=4
+ )
+ (func $~lib/rt/itcms/Object#set:prev (param $this i32) (param $prev i32)
+  local.get $this
+  local.get $prev
+  i32.store offset=8
+ )
+ (func $~lib/rt/itcms/initLazy (param $space i32) (result i32)
+  local.get $space
+  local.get $space
+  call $~lib/rt/itcms/Object#set:nextWithColor
+  local.get $space
+  local.get $space
+  call $~lib/rt/itcms/Object#set:prev
+  local.get $space
+  return
+ )
+ (func $~lib/rt/itcms/Object#get:nextWithColor (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=4
+ )
+ (func $~lib/rt/itcms/Object#get:next (param $this i32) (result i32)
+  local.get $this
+  call $~lib/rt/itcms/Object#get:nextWithColor
+  i32.const 3
+  i32.const -1
+  i32.xor
+  i32.and
+  return
+ )
+ (func $~lib/rt/itcms/Object#get:color (param $this i32) (result i32)
+  local.get $this
+  call $~lib/rt/itcms/Object#get:nextWithColor
+  i32.const 3
+  i32.and
+  return
+ )
+ (func $~lib/rt/itcms/visitRoots (param $cookie i32)
+  (local $pn i32)
+  (local $iter i32)
+  local.get $cookie
+  call $~lib/rt/__visit_globals
+  global.get $~lib/rt/itcms/pinSpace
+  local.set $pn
+  local.get $pn
+  call $~lib/rt/itcms/Object#get:next
+  local.set $iter
+  loop $while-continue|0
+   local.get $iter
+   local.get $pn
+   i32.ne
+   if
+    i32.const 1
+    drop
+    local.get $iter
+    call $~lib/rt/itcms/Object#get:color
+    i32.const 3
+    i32.eq
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 128
+     i32.const 160
+     i32.const 16
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $iter
+    i32.const 20
+    i32.add
+    local.get $cookie
+    call $~lib/rt/__visit_members
+    local.get $iter
+    call $~lib/rt/itcms/Object#get:next
+    local.set $iter
+    br $while-continue|0
+   end
+  end
+ )
+ (func $~lib/rt/itcms/Object#set:color (param $this i32) (param $color i32)
+  local.get $this
+  local.get $this
+  call $~lib/rt/itcms/Object#get:nextWithColor
+  i32.const 3
+  i32.const -1
+  i32.xor
+  i32.and
+  local.get $color
+  i32.or
+  call $~lib/rt/itcms/Object#set:nextWithColor
+ )
+ (func $~lib/rt/itcms/Object#get:prev (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=8
+ )
+ (func $~lib/rt/itcms/Object#set:next (param $this i32) (param $obj i32)
+  local.get $this
+  local.get $obj
+  local.get $this
+  call $~lib/rt/itcms/Object#get:nextWithColor
+  i32.const 3
+  i32.and
+  i32.or
+  call $~lib/rt/itcms/Object#set:nextWithColor
+ )
+ (func $~lib/rt/itcms/Object#unlink (param $this i32)
+  (local $next i32)
+  (local $prev i32)
+  local.get $this
+  call $~lib/rt/itcms/Object#get:next
+  local.set $next
+  local.get $next
+  i32.const 0
+  i32.eq
+  if
+   i32.const 1
+   drop
+   local.get $this
+   call $~lib/rt/itcms/Object#get:prev
+   i32.const 0
+   i32.eq
+   if (result i32)
+    local.get $this
+    global.get $~lib/memory/__heap_base
+    i32.lt_u
+   else
+    i32.const 0
+   end
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 128
+    i32.const 128
+    i32.const 18
+    call $~lib/builtins/abort
+    unreachable
+   end
+   return
+  end
+  local.get $this
+  call $~lib/rt/itcms/Object#get:prev
+  local.set $prev
+  i32.const 1
+  drop
+  local.get $prev
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 128
+   i32.const 132
+   i32.const 16
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $next
+  local.get $prev
+  call $~lib/rt/itcms/Object#set:prev
+  local.get $prev
+  local.get $next
+  call $~lib/rt/itcms/Object#set:next
+ )
+ (func $~lib/rt/itcms/Object#get:rtId (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=12
+ )
+ (func $~lib/shared/typeinfo/Typeinfo#get:flags (param $this i32) (result i32)
+  local.get $this
+  i32.load
+ )
+ (func $~lib/rt/__typeinfo (param $id i32) (result i32)
+  (local $ptr i32)
+  global.get $~lib/rt/__rtti_base
+  local.set $ptr
+  local.get $id
+  local.get $ptr
+  i32.load
+  i32.gt_u
+  if
+   i32.const 256
+   i32.const 320
+   i32.const 21
+   i32.const 28
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $ptr
+  i32.const 4
+  i32.add
+  local.get $id
+  i32.const 4
+  i32.mul
+  i32.add
+  call $~lib/shared/typeinfo/Typeinfo#get:flags
+  return
+ )
+ (func $~lib/rt/itcms/Object#get:isPointerfree (param $this i32) (result i32)
+  (local $rtId i32)
+  local.get $this
+  call $~lib/rt/itcms/Object#get:rtId
+  local.set $rtId
+  local.get $rtId
+  i32.const 2
+  i32.le_u
+  if (result i32)
+   i32.const 1
+  else
+   local.get $rtId
+   call $~lib/rt/__typeinfo
+   i32.const 32
+   i32.and
+   i32.const 0
+   i32.ne
+  end
+  return
+ )
+ (func $~lib/rt/itcms/Object#linkTo (param $this i32) (param $list i32) (param $withColor i32)
+  (local $prev i32)
+  local.get $list
+  call $~lib/rt/itcms/Object#get:prev
+  local.set $prev
+  local.get $this
+  local.get $list
+  local.get $withColor
+  i32.or
+  call $~lib/rt/itcms/Object#set:nextWithColor
+  local.get $this
+  local.get $prev
+  call $~lib/rt/itcms/Object#set:prev
+  local.get $prev
+  local.get $this
+  call $~lib/rt/itcms/Object#set:next
+  local.get $list
+  local.get $this
+  call $~lib/rt/itcms/Object#set:prev
+ )
+ (func $~lib/rt/itcms/Object#makeGray (param $this i32)
+  (local $1 i32)
+  local.get $this
+  global.get $~lib/rt/itcms/iter
+  i32.eq
+  if
+   local.get $this
+   call $~lib/rt/itcms/Object#get:prev
+   local.tee $1
+   i32.eqz
+   if (result i32)
+    i32.const 0
+    i32.const 128
+    i32.const 148
+    i32.const 30
+    call $~lib/builtins/abort
+    unreachable
+   else
+    local.get $1
+   end
+   global.set $~lib/rt/itcms/iter
+  end
+  local.get $this
+  call $~lib/rt/itcms/Object#unlink
+  local.get $this
+  global.get $~lib/rt/itcms/toSpace
+  local.get $this
+  call $~lib/rt/itcms/Object#get:isPointerfree
+  if (result i32)
+   global.get $~lib/rt/itcms/white
+   i32.eqz
+  else
+   i32.const 2
+  end
+  call $~lib/rt/itcms/Object#linkTo
+ )
+ (func $~lib/rt/itcms/__visit (param $ptr i32) (param $cookie i32)
+  (local $obj i32)
+  local.get $ptr
+  i32.eqz
+  if
+   return
+  end
+  local.get $ptr
+  i32.const 20
+  i32.sub
+  local.set $obj
+  i32.const 0
+  drop
+  local.get $obj
+  call $~lib/rt/itcms/Object#get:color
+  global.get $~lib/rt/itcms/white
+  i32.eq
+  if
+   local.get $obj
+   call $~lib/rt/itcms/Object#makeGray
+   global.get $~lib/rt/itcms/visitCount
+   i32.const 1
+   i32.add
+   global.set $~lib/rt/itcms/visitCount
+  end
+ )
+ (func $~lib/rt/itcms/visitStack (param $cookie i32)
+  (local $ptr i32)
+  global.get $~lib/memory/__stack_pointer
+  local.set $ptr
+  loop $while-continue|0
+   local.get $ptr
+   global.get $~lib/memory/__heap_base
+   i32.lt_u
+   if
+    local.get $ptr
+    i32.load
+    local.get $cookie
+    call $~lib/rt/itcms/__visit
+    local.get $ptr
+    i32.const 4
+    i32.add
+    local.set $ptr
+    br $while-continue|0
+   end
+  end
+ )
+ (func $~lib/rt/common/BLOCK#get:mmInfo (param $this i32) (result i32)
+  local.get $this
+  i32.load
+ )
+ (func $~lib/rt/itcms/Object#get:size (param $this i32) (result i32)
+  i32.const 4
+  local.get $this
+  call $~lib/rt/common/BLOCK#get:mmInfo
+  i32.const 3
+  i32.const -1
+  i32.xor
+  i32.and
+  i32.add
+  return
+ )
+ (func $~lib/rt/tlsf/Root#set:flMap (param $this i32) (param $flMap i32)
+  local.get $this
+  local.get $flMap
+  i32.store
+ )
+ (func $~lib/rt/common/BLOCK#set:mmInfo (param $this i32) (param $mmInfo i32)
+  local.get $this
+  local.get $mmInfo
+  i32.store
+ )
+ (func $~lib/rt/tlsf/Block#set:prev (param $this i32) (param $prev i32)
+  local.get $this
+  local.get $prev
+  i32.store offset=4
+ )
+ (func $~lib/rt/tlsf/Block#set:next (param $this i32) (param $next i32)
+  local.get $this
+  local.get $next
+  i32.store offset=8
+ )
+ (func $~lib/rt/tlsf/Block#get:prev (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=4
+ )
+ (func $~lib/rt/tlsf/Block#get:next (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=8
+ )
+ (func $~lib/rt/tlsf/Root#get:flMap (param $this i32) (result i32)
+  local.get $this
+  i32.load
+ )
+ (func $~lib/rt/tlsf/removeBlock (param $root i32) (param $block i32)
+  (local $blockInfo i32)
+  (local $size i32)
+  (local $fl i32)
+  (local $sl i32)
+  (local $6 i32)
+  (local $7 i32)
+  (local $boundedSize i32)
+  (local $prev i32)
+  (local $next i32)
+  (local $root|11 i32)
+  (local $fl|12 i32)
+  (local $sl|13 i32)
+  (local $root|14 i32)
+  (local $fl|15 i32)
+  (local $sl|16 i32)
+  (local $head i32)
+  (local $root|18 i32)
+  (local $fl|19 i32)
+  (local $slMap i32)
+  (local $root|21 i32)
+  (local $fl|22 i32)
+  (local $slMap|23 i32)
+  local.get $block
+  call $~lib/rt/common/BLOCK#get:mmInfo
+  local.set $blockInfo
+  i32.const 1
+  drop
+  local.get $blockInfo
+  i32.const 1
+  i32.and
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 268
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $blockInfo
+  i32.const 3
+  i32.const -1
+  i32.xor
+  i32.and
+  local.set $size
+  i32.const 1
+  drop
+  local.get $size
+  i32.const 12
+  i32.ge_u
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 270
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $size
+  i32.const 256
+  i32.lt_u
+  if
+   i32.const 0
+   local.set $fl
+   local.get $size
+   i32.const 4
+   i32.shr_u
+   local.set $sl
+  else
+   local.get $size
+   local.tee $6
+   i32.const 1073741820
+   local.tee $7
+   local.get $6
+   local.get $7
+   i32.lt_u
+   select
+   local.set $boundedSize
+   i32.const 31
+   local.get $boundedSize
+   i32.clz
+   i32.sub
+   local.set $fl
+   local.get $boundedSize
+   local.get $fl
+   i32.const 4
+   i32.sub
+   i32.shr_u
+   i32.const 1
+   i32.const 4
+   i32.shl
+   i32.xor
+   local.set $sl
+   local.get $fl
+   i32.const 8
+   i32.const 1
+   i32.sub
+   i32.sub
+   local.set $fl
+  end
+  i32.const 1
+  drop
+  local.get $fl
+  i32.const 23
+  i32.lt_u
+  if (result i32)
+   local.get $sl
+   i32.const 16
+   i32.lt_u
+  else
+   i32.const 0
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 284
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $block
+  call $~lib/rt/tlsf/Block#get:prev
+  local.set $prev
+  local.get $block
+  call $~lib/rt/tlsf/Block#get:next
+  local.set $next
+  local.get $prev
+  if
+   local.get $prev
+   local.get $next
+   call $~lib/rt/tlsf/Block#set:next
+  end
+  local.get $next
+  if
+   local.get $next
+   local.get $prev
+   call $~lib/rt/tlsf/Block#set:prev
+  end
+  local.get $block
+  block $~lib/rt/tlsf/GETHEAD|inlined.0 (result i32)
+   local.get $root
+   local.set $root|11
+   local.get $fl
+   local.set $fl|12
+   local.get $sl
+   local.set $sl|13
+   local.get $root|11
+   local.get $fl|12
+   i32.const 4
+   i32.shl
+   local.get $sl|13
+   i32.add
+   i32.const 2
+   i32.shl
+   i32.add
+   i32.load offset=96
+   br $~lib/rt/tlsf/GETHEAD|inlined.0
+  end
+  i32.eq
+  if
+   local.get $root
+   local.set $root|14
+   local.get $fl
+   local.set $fl|15
+   local.get $sl
+   local.set $sl|16
+   local.get $next
+   local.set $head
+   local.get $root|14
+   local.get $fl|15
+   i32.const 4
+   i32.shl
+   local.get $sl|16
+   i32.add
+   i32.const 2
+   i32.shl
+   i32.add
+   local.get $head
+   i32.store offset=96
+   local.get $next
+   i32.eqz
+   if
+    block $~lib/rt/tlsf/GETSL|inlined.0 (result i32)
+     local.get $root
+     local.set $root|18
+     local.get $fl
+     local.set $fl|19
+     local.get $root|18
+     local.get $fl|19
+     i32.const 2
+     i32.shl
+     i32.add
+     i32.load offset=4
+     br $~lib/rt/tlsf/GETSL|inlined.0
+    end
+    local.set $slMap
+    local.get $root
+    local.set $root|21
+    local.get $fl
+    local.set $fl|22
+    local.get $slMap
+    i32.const 1
+    local.get $sl
+    i32.shl
+    i32.const -1
+    i32.xor
+    i32.and
+    local.tee $slMap
+    local.set $slMap|23
+    local.get $root|21
+    local.get $fl|22
+    i32.const 2
+    i32.shl
+    i32.add
+    local.get $slMap|23
+    i32.store offset=4
+    local.get $slMap
+    i32.eqz
+    if
+     local.get $root
+     local.get $root
+     call $~lib/rt/tlsf/Root#get:flMap
+     i32.const 1
+     local.get $fl
+     i32.shl
+     i32.const -1
+     i32.xor
+     i32.and
+     call $~lib/rt/tlsf/Root#set:flMap
+    end
+   end
+  end
+ )
+ (func $~lib/rt/tlsf/insertBlock (param $root i32) (param $block i32)
+  (local $blockInfo i32)
+  (local $block|3 i32)
+  (local $right i32)
+  (local $rightInfo i32)
+  (local $block|6 i32)
+  (local $block|7 i32)
+  (local $left i32)
+  (local $leftInfo i32)
+  (local $size i32)
+  (local $fl i32)
+  (local $sl i32)
+  (local $13 i32)
+  (local $14 i32)
+  (local $boundedSize i32)
+  (local $root|16 i32)
+  (local $fl|17 i32)
+  (local $sl|18 i32)
+  (local $head i32)
+  (local $root|20 i32)
+  (local $fl|21 i32)
+  (local $sl|22 i32)
+  (local $head|23 i32)
+  (local $root|24 i32)
+  (local $fl|25 i32)
+  (local $root|26 i32)
+  (local $fl|27 i32)
+  (local $slMap i32)
+  i32.const 1
+  drop
+  local.get $block
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 201
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $block
+  call $~lib/rt/common/BLOCK#get:mmInfo
+  local.set $blockInfo
+  i32.const 1
+  drop
+  local.get $blockInfo
+  i32.const 1
+  i32.and
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 203
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  block $~lib/rt/tlsf/GETRIGHT|inlined.0 (result i32)
+   local.get $block
+   local.set $block|3
+   local.get $block|3
+   i32.const 4
+   i32.add
+   local.get $block|3
+   call $~lib/rt/common/BLOCK#get:mmInfo
+   i32.const 3
+   i32.const -1
+   i32.xor
+   i32.and
+   i32.add
+   br $~lib/rt/tlsf/GETRIGHT|inlined.0
+  end
+  local.set $right
+  local.get $right
+  call $~lib/rt/common/BLOCK#get:mmInfo
+  local.set $rightInfo
+  local.get $rightInfo
+  i32.const 1
+  i32.and
+  if
+   local.get $root
+   local.get $right
+   call $~lib/rt/tlsf/removeBlock
+   local.get $block
+   local.get $blockInfo
+   i32.const 4
+   i32.add
+   local.get $rightInfo
+   i32.const 3
+   i32.const -1
+   i32.xor
+   i32.and
+   i32.add
+   local.tee $blockInfo
+   call $~lib/rt/common/BLOCK#set:mmInfo
+   block $~lib/rt/tlsf/GETRIGHT|inlined.1 (result i32)
+    local.get $block
+    local.set $block|6
+    local.get $block|6
+    i32.const 4
+    i32.add
+    local.get $block|6
+    call $~lib/rt/common/BLOCK#get:mmInfo
+    i32.const 3
+    i32.const -1
+    i32.xor
+    i32.and
+    i32.add
+    br $~lib/rt/tlsf/GETRIGHT|inlined.1
+   end
+   local.set $right
+   local.get $right
+   call $~lib/rt/common/BLOCK#get:mmInfo
+   local.set $rightInfo
+  end
+  local.get $blockInfo
+  i32.const 2
+  i32.and
+  if
+   block $~lib/rt/tlsf/GETFREELEFT|inlined.0 (result i32)
+    local.get $block
+    local.set $block|7
+    local.get $block|7
+    i32.const 4
+    i32.sub
+    i32.load
+    br $~lib/rt/tlsf/GETFREELEFT|inlined.0
+   end
+   local.set $left
+   local.get $left
+   call $~lib/rt/common/BLOCK#get:mmInfo
+   local.set $leftInfo
+   i32.const 1
+   drop
+   local.get $leftInfo
+   i32.const 1
+   i32.and
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 400
+    i32.const 221
+    i32.const 16
+    call $~lib/builtins/abort
+    unreachable
+   end
+   local.get $root
+   local.get $left
+   call $~lib/rt/tlsf/removeBlock
+   local.get $left
+   local.set $block
+   local.get $block
+   local.get $leftInfo
+   i32.const 4
+   i32.add
+   local.get $blockInfo
+   i32.const 3
+   i32.const -1
+   i32.xor
+   i32.and
+   i32.add
+   local.tee $blockInfo
+   call $~lib/rt/common/BLOCK#set:mmInfo
+  end
+  local.get $right
+  local.get $rightInfo
+  i32.const 2
+  i32.or
+  call $~lib/rt/common/BLOCK#set:mmInfo
+  local.get $blockInfo
+  i32.const 3
+  i32.const -1
+  i32.xor
+  i32.and
+  local.set $size
+  i32.const 1
+  drop
+  local.get $size
+  i32.const 12
+  i32.ge_u
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 233
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 1
+  drop
+  local.get $block
+  i32.const 4
+  i32.add
+  local.get $size
+  i32.add
+  local.get $right
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 234
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $right
+  i32.const 4
+  i32.sub
+  local.get $block
+  i32.store
+  local.get $size
+  i32.const 256
+  i32.lt_u
+  if
+   i32.const 0
+   local.set $fl
+   local.get $size
+   i32.const 4
+   i32.shr_u
+   local.set $sl
+  else
+   local.get $size
+   local.tee $13
+   i32.const 1073741820
+   local.tee $14
+   local.get $13
+   local.get $14
+   i32.lt_u
+   select
+   local.set $boundedSize
+   i32.const 31
+   local.get $boundedSize
+   i32.clz
+   i32.sub
+   local.set $fl
+   local.get $boundedSize
+   local.get $fl
+   i32.const 4
+   i32.sub
+   i32.shr_u
+   i32.const 1
+   i32.const 4
+   i32.shl
+   i32.xor
+   local.set $sl
+   local.get $fl
+   i32.const 8
+   i32.const 1
+   i32.sub
+   i32.sub
+   local.set $fl
+  end
+  i32.const 1
+  drop
+  local.get $fl
+  i32.const 23
+  i32.lt_u
+  if (result i32)
+   local.get $sl
+   i32.const 16
+   i32.lt_u
+  else
+   i32.const 0
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 251
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  block $~lib/rt/tlsf/GETHEAD|inlined.1 (result i32)
+   local.get $root
+   local.set $root|16
+   local.get $fl
+   local.set $fl|17
+   local.get $sl
+   local.set $sl|18
+   local.get $root|16
+   local.get $fl|17
+   i32.const 4
+   i32.shl
+   local.get $sl|18
+   i32.add
+   i32.const 2
+   i32.shl
+   i32.add
+   i32.load offset=96
+   br $~lib/rt/tlsf/GETHEAD|inlined.1
+  end
+  local.set $head
+  local.get $block
+  i32.const 0
+  call $~lib/rt/tlsf/Block#set:prev
+  local.get $block
+  local.get $head
+  call $~lib/rt/tlsf/Block#set:next
+  local.get $head
+  if
+   local.get $head
+   local.get $block
+   call $~lib/rt/tlsf/Block#set:prev
+  end
+  local.get $root
+  local.set $root|20
+  local.get $fl
+  local.set $fl|21
+  local.get $sl
+  local.set $sl|22
+  local.get $block
+  local.set $head|23
+  local.get $root|20
+  local.get $fl|21
+  i32.const 4
+  i32.shl
+  local.get $sl|22
+  i32.add
+  i32.const 2
+  i32.shl
+  i32.add
+  local.get $head|23
+  i32.store offset=96
+  local.get $root
+  local.get $root
+  call $~lib/rt/tlsf/Root#get:flMap
+  i32.const 1
+  local.get $fl
+  i32.shl
+  i32.or
+  call $~lib/rt/tlsf/Root#set:flMap
+  local.get $root
+  local.set $root|26
+  local.get $fl
+  local.set $fl|27
+  block $~lib/rt/tlsf/GETSL|inlined.1 (result i32)
+   local.get $root
+   local.set $root|24
+   local.get $fl
+   local.set $fl|25
+   local.get $root|24
+   local.get $fl|25
+   i32.const 2
+   i32.shl
+   i32.add
+   i32.load offset=4
+   br $~lib/rt/tlsf/GETSL|inlined.1
+  end
+  i32.const 1
+  local.get $sl
+  i32.shl
+  i32.or
+  local.set $slMap
+  local.get $root|26
+  local.get $fl|27
+  i32.const 2
+  i32.shl
+  i32.add
+  local.get $slMap
+  i32.store offset=4
+ )
+ (func $~lib/rt/tlsf/addMemory (param $root i32) (param $start i32) (param $endU64 i64) (result i32)
+  (local $end i32)
+  (local $root|4 i32)
+  (local $tail i32)
+  (local $tailInfo i32)
+  (local $size i32)
+  (local $leftSize i32)
+  (local $left i32)
+  (local $root|10 i32)
+  (local $tail|11 i32)
+  local.get $endU64
+  i32.wrap_i64
+  local.set $end
+  i32.const 1
+  drop
+  local.get $start
+  i64.extend_i32_u
+  local.get $endU64
+  i64.le_u
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 382
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $start
+  i32.const 4
+  i32.add
+  i32.const 15
+  i32.add
+  i32.const 15
+  i32.const -1
+  i32.xor
+  i32.and
+  i32.const 4
+  i32.sub
+  local.set $start
+  local.get $end
+  i32.const 15
+  i32.const -1
+  i32.xor
+  i32.and
+  local.set $end
+  block $~lib/rt/tlsf/GETTAIL|inlined.0 (result i32)
+   local.get $root
+   local.set $root|4
+   local.get $root|4
+   i32.load offset=1568
+   br $~lib/rt/tlsf/GETTAIL|inlined.0
+  end
+  local.set $tail
+  i32.const 0
+  local.set $tailInfo
+  local.get $tail
+  if
+   i32.const 1
+   drop
+   local.get $start
+   local.get $tail
+   i32.const 4
+   i32.add
+   i32.ge_u
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 400
+    i32.const 389
+    i32.const 16
+    call $~lib/builtins/abort
+    unreachable
+   end
+   local.get $start
+   i32.const 16
+   i32.sub
+   local.get $tail
+   i32.eq
+   if
+    local.get $start
+    i32.const 16
+    i32.sub
+    local.set $start
+    local.get $tail
+    call $~lib/rt/common/BLOCK#get:mmInfo
+    local.set $tailInfo
+   else
+   end
+  else
+   i32.const 1
+   drop
+   local.get $start
+   local.get $root
+   i32.const 1572
+   i32.add
+   i32.ge_u
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 400
+    i32.const 402
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  local.get $end
+  local.get $start
+  i32.sub
+  local.set $size
+  local.get $size
+  i32.const 4
+  i32.const 12
+  i32.add
+  i32.const 4
+  i32.add
+  i32.lt_u
+  if
+   i32.const 0
+   return
+  end
+  local.get $size
+  i32.const 2
+  i32.const 4
+  i32.mul
+  i32.sub
+  local.set $leftSize
+  local.get $start
+  local.set $left
+  local.get $left
+  local.get $leftSize
+  i32.const 1
+  i32.or
+  local.get $tailInfo
+  i32.const 2
+  i32.and
+  i32.or
+  call $~lib/rt/common/BLOCK#set:mmInfo
+  local.get $left
+  i32.const 0
+  call $~lib/rt/tlsf/Block#set:prev
+  local.get $left
+  i32.const 0
+  call $~lib/rt/tlsf/Block#set:next
+  local.get $start
+  i32.const 4
+  i32.add
+  local.get $leftSize
+  i32.add
+  local.set $tail
+  local.get $tail
+  i32.const 0
+  i32.const 2
+  i32.or
+  call $~lib/rt/common/BLOCK#set:mmInfo
+  local.get $root
+  local.set $root|10
+  local.get $tail
+  local.set $tail|11
+  local.get $root|10
+  local.get $tail|11
+  i32.store offset=1568
+  local.get $root
+  local.get $left
+  call $~lib/rt/tlsf/insertBlock
+  i32.const 1
+  return
+ )
+ (func $~lib/rt/tlsf/initialize
+  (local $rootOffset i32)
+  (local $pagesBefore i32)
+  (local $pagesNeeded i32)
+  (local $root i32)
+  (local $root|4 i32)
+  (local $tail i32)
+  (local $fl i32)
+  (local $root|7 i32)
+  (local $fl|8 i32)
+  (local $slMap i32)
+  (local $sl i32)
+  (local $root|11 i32)
+  (local $fl|12 i32)
+  (local $sl|13 i32)
+  (local $head i32)
+  (local $memStart i32)
+  i32.const 0
+  drop
+  global.get $~lib/memory/__heap_base
+  i32.const 15
+  i32.add
+  i32.const 15
+  i32.const -1
+  i32.xor
+  i32.and
+  local.set $rootOffset
+  memory.size
+  local.set $pagesBefore
+  local.get $rootOffset
+  i32.const 1572
+  i32.add
+  i32.const 65535
+  i32.add
+  i32.const 65535
+  i32.const -1
+  i32.xor
+  i32.and
+  i32.const 16
+  i32.shr_u
+  local.set $pagesNeeded
+  local.get $pagesNeeded
+  local.get $pagesBefore
+  i32.gt_s
+  if (result i32)
+   local.get $pagesNeeded
+   local.get $pagesBefore
+   i32.sub
+   memory.grow
+   i32.const 0
+   i32.lt_s
+  else
+   i32.const 0
+  end
+  if
+   unreachable
+  end
+  local.get $rootOffset
+  local.set $root
+  local.get $root
+  i32.const 0
+  call $~lib/rt/tlsf/Root#set:flMap
+  local.get $root
+  local.set $root|4
+  i32.const 0
+  local.set $tail
+  local.get $root|4
+  local.get $tail
+  i32.store offset=1568
+  i32.const 0
+  local.set $fl
+  loop $for-loop|0
+   local.get $fl
+   i32.const 23
+   i32.lt_u
+   if
+    local.get $root
+    local.set $root|7
+    local.get $fl
+    local.set $fl|8
+    i32.const 0
+    local.set $slMap
+    local.get $root|7
+    local.get $fl|8
+    i32.const 2
+    i32.shl
+    i32.add
+    local.get $slMap
+    i32.store offset=4
+    i32.const 0
+    local.set $sl
+    loop $for-loop|1
+     local.get $sl
+     i32.const 16
+     i32.lt_u
+     if
+      local.get $root
+      local.set $root|11
+      local.get $fl
+      local.set $fl|12
+      local.get $sl
+      local.set $sl|13
+      i32.const 0
+      local.set $head
+      local.get $root|11
+      local.get $fl|12
+      i32.const 4
+      i32.shl
+      local.get $sl|13
+      i32.add
+      i32.const 2
+      i32.shl
+      i32.add
+      local.get $head
+      i32.store offset=96
+      local.get $sl
+      i32.const 1
+      i32.add
+      local.set $sl
+      br $for-loop|1
+     end
+    end
+    local.get $fl
+    i32.const 1
+    i32.add
+    local.set $fl
+    br $for-loop|0
+   end
+  end
+  local.get $rootOffset
+  i32.const 1572
+  i32.add
+  local.set $memStart
+  i32.const 0
+  drop
+  local.get $root
+  local.get $memStart
+  memory.size
+  i64.extend_i32_s
+  i64.const 16
+  i64.shl
+  call $~lib/rt/tlsf/addMemory
+  drop
+  local.get $root
+  global.set $~lib/rt/tlsf/ROOT
+ )
+ (func $~lib/rt/tlsf/checkUsedBlock (param $ptr i32) (result i32)
+  (local $block i32)
+  local.get $ptr
+  i32.const 4
+  i32.sub
+  local.set $block
+  local.get $ptr
+  i32.const 0
+  i32.ne
+  if (result i32)
+   local.get $ptr
+   i32.const 15
+   i32.and
+   i32.eqz
+  else
+   i32.const 0
+  end
+  if (result i32)
+   local.get $block
+   call $~lib/rt/common/BLOCK#get:mmInfo
+   i32.const 1
+   i32.and
+   i32.eqz
+  else
+   i32.const 0
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 562
+   i32.const 3
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $block
+  return
+ )
+ (func $~lib/rt/tlsf/freeBlock (param $root i32) (param $block i32)
+  i32.const 0
+  drop
+  local.get $block
+  local.get $block
+  call $~lib/rt/common/BLOCK#get:mmInfo
+  i32.const 1
+  i32.or
+  call $~lib/rt/common/BLOCK#set:mmInfo
+  local.get $root
+  local.get $block
+  call $~lib/rt/tlsf/insertBlock
+ )
+ (func $~lib/rt/tlsf/__free (param $ptr i32)
+  local.get $ptr
+  global.get $~lib/memory/__heap_base
+  i32.lt_u
+  if
+   return
+  end
+  global.get $~lib/rt/tlsf/ROOT
+  i32.eqz
+  if
+   call $~lib/rt/tlsf/initialize
+  end
+  global.get $~lib/rt/tlsf/ROOT
+  local.get $ptr
+  call $~lib/rt/tlsf/checkUsedBlock
+  call $~lib/rt/tlsf/freeBlock
+ )
+ (func $~lib/rt/itcms/free (param $obj i32)
+  local.get $obj
+  global.get $~lib/memory/__heap_base
+  i32.lt_u
+  if
+   local.get $obj
+   i32.const 0
+   call $~lib/rt/itcms/Object#set:nextWithColor
+   local.get $obj
+   i32.const 0
+   call $~lib/rt/itcms/Object#set:prev
+  else
+   global.get $~lib/rt/itcms/total
+   local.get $obj
+   call $~lib/rt/itcms/Object#get:size
+   i32.sub
+   global.set $~lib/rt/itcms/total
+   i32.const 0
+   drop
+   local.get $obj
+   i32.const 4
+   i32.add
+   call $~lib/rt/tlsf/__free
+  end
+ )
+ (func $~lib/rt/itcms/step (result i32)
+  (local $obj i32)
+  (local $1 i32)
+  (local $black i32)
+  (local $from i32)
+  block $break|0
+   block $case2|0
+    block $case1|0
+     block $case0|0
+      global.get $~lib/rt/itcms/state
+      local.set $1
+      local.get $1
+      i32.const 0
+      i32.eq
+      br_if $case0|0
+      local.get $1
+      i32.const 1
+      i32.eq
+      br_if $case1|0
+      local.get $1
+      i32.const 2
+      i32.eq
+      br_if $case2|0
+      br $break|0
+     end
+     i32.const 1
+     global.set $~lib/rt/itcms/state
+     i32.const 0
+     global.set $~lib/rt/itcms/visitCount
+     i32.const 0
+     call $~lib/rt/itcms/visitRoots
+     global.get $~lib/rt/itcms/toSpace
+     global.set $~lib/rt/itcms/iter
+     global.get $~lib/rt/itcms/visitCount
+     i32.const 1
+     i32.mul
+     return
+    end
+    global.get $~lib/rt/itcms/white
+    i32.eqz
+    local.set $black
+    global.get $~lib/rt/itcms/iter
+    call $~lib/rt/itcms/Object#get:next
+    local.set $obj
+    loop $while-continue|1
+     local.get $obj
+     global.get $~lib/rt/itcms/toSpace
+     i32.ne
+     if
+      local.get $obj
+      global.set $~lib/rt/itcms/iter
+      local.get $obj
+      call $~lib/rt/itcms/Object#get:color
+      local.get $black
+      i32.ne
+      if
+       local.get $obj
+       local.get $black
+       call $~lib/rt/itcms/Object#set:color
+       i32.const 0
+       global.set $~lib/rt/itcms/visitCount
+       local.get $obj
+       i32.const 20
+       i32.add
+       i32.const 0
+       call $~lib/rt/__visit_members
+       global.get $~lib/rt/itcms/visitCount
+       i32.const 1
+       i32.mul
+       return
+      end
+      local.get $obj
+      call $~lib/rt/itcms/Object#get:next
+      local.set $obj
+      br $while-continue|1
+     end
+    end
+    i32.const 0
+    global.set $~lib/rt/itcms/visitCount
+    i32.const 0
+    call $~lib/rt/itcms/visitRoots
+    global.get $~lib/rt/itcms/iter
+    call $~lib/rt/itcms/Object#get:next
+    local.set $obj
+    local.get $obj
+    global.get $~lib/rt/itcms/toSpace
+    i32.eq
+    if
+     i32.const 0
+     call $~lib/rt/itcms/visitStack
+     global.get $~lib/rt/itcms/iter
+     call $~lib/rt/itcms/Object#get:next
+     local.set $obj
+     loop $while-continue|2
+      local.get $obj
+      global.get $~lib/rt/itcms/toSpace
+      i32.ne
+      if
+       local.get $obj
+       call $~lib/rt/itcms/Object#get:color
+       local.get $black
+       i32.ne
+       if
+        local.get $obj
+        local.get $black
+        call $~lib/rt/itcms/Object#set:color
+        local.get $obj
+        i32.const 20
+        i32.add
+        i32.const 0
+        call $~lib/rt/__visit_members
+       end
+       local.get $obj
+       call $~lib/rt/itcms/Object#get:next
+       local.set $obj
+       br $while-continue|2
+      end
+     end
+     global.get $~lib/rt/itcms/fromSpace
+     local.set $from
+     global.get $~lib/rt/itcms/toSpace
+     global.set $~lib/rt/itcms/fromSpace
+     local.get $from
+     global.set $~lib/rt/itcms/toSpace
+     local.get $black
+     global.set $~lib/rt/itcms/white
+     local.get $from
+     call $~lib/rt/itcms/Object#get:next
+     global.set $~lib/rt/itcms/iter
+     i32.const 2
+     global.set $~lib/rt/itcms/state
+    end
+    global.get $~lib/rt/itcms/visitCount
+    i32.const 1
+    i32.mul
+    return
+   end
+   global.get $~lib/rt/itcms/iter
+   local.set $obj
+   local.get $obj
+   global.get $~lib/rt/itcms/toSpace
+   i32.ne
+   if
+    local.get $obj
+    call $~lib/rt/itcms/Object#get:next
+    global.set $~lib/rt/itcms/iter
+    i32.const 1
+    drop
+    local.get $obj
+    call $~lib/rt/itcms/Object#get:color
+    global.get $~lib/rt/itcms/white
+    i32.eqz
+    i32.eq
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 128
+     i32.const 229
+     i32.const 20
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $obj
+    call $~lib/rt/itcms/free
+    i32.const 10
+    return
+   end
+   global.get $~lib/rt/itcms/toSpace
+   global.get $~lib/rt/itcms/toSpace
+   call $~lib/rt/itcms/Object#set:nextWithColor
+   global.get $~lib/rt/itcms/toSpace
+   global.get $~lib/rt/itcms/toSpace
+   call $~lib/rt/itcms/Object#set:prev
+   i32.const 0
+   global.set $~lib/rt/itcms/state
+   br $break|0
+  end
+  i32.const 0
+  return
+ )
+ (func $~lib/rt/itcms/interrupt
+  (local $budget i32)
+  i32.const 0
+  drop
+  i32.const 0
+  drop
+  i32.const 1024
+  i32.const 200
+  i32.mul
+  i32.const 100
+  i32.div_u
+  local.set $budget
+  loop $do-loop|0
+   local.get $budget
+   call $~lib/rt/itcms/step
+   i32.sub
+   local.set $budget
+   global.get $~lib/rt/itcms/state
+   i32.const 0
+   i32.eq
+   if
+    i32.const 0
+    drop
+    i32.const 200
+    i32.const 100
+    i32.rem_u
+    i32.const 0
+    i32.eq
+    drop
+    global.get $~lib/rt/itcms/total
+    i32.const 200
+    i32.const 100
+    i32.div_u
+    i32.mul
+    i32.const 1024
+    i32.add
+    global.set $~lib/rt/itcms/threshold
+    i32.const 0
+    drop
+    return
+   end
+   local.get $budget
+   i32.const 0
+   i32.gt_s
+   br_if $do-loop|0
+  end
+  i32.const 0
+  drop
+  global.get $~lib/rt/itcms/total
+  i32.const 1024
+  global.get $~lib/rt/itcms/total
+  global.get $~lib/rt/itcms/threshold
+  i32.sub
+  i32.const 1024
+  i32.lt_u
+  i32.mul
+  i32.add
+  global.set $~lib/rt/itcms/threshold
+  i32.const 0
+  drop
+ )
+ (func $~lib/rt/tlsf/computeSize (param $size i32) (result i32)
+  local.get $size
+  i32.const 12
+  i32.le_u
+  if (result i32)
+   i32.const 12
+  else
+   local.get $size
+   i32.const 4
+   i32.add
+   i32.const 15
+   i32.add
+   i32.const 15
+   i32.const -1
+   i32.xor
+   i32.and
+   i32.const 4
+   i32.sub
+  end
+  return
+ )
+ (func $~lib/rt/tlsf/prepareSize (param $size i32) (result i32)
+  local.get $size
+  i32.const 1073741820
+  i32.gt_u
+  if
+   i32.const 64
+   i32.const 400
+   i32.const 461
+   i32.const 29
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $size
+  return_call $~lib/rt/tlsf/computeSize
+ )
+ (func $~lib/rt/tlsf/roundSize (param $size i32) (result i32)
+  local.get $size
+  i32.const 536870910
+  i32.lt_u
+  if (result i32)
+   local.get $size
+   i32.const 1
+   i32.const 27
+   local.get $size
+   i32.clz
+   i32.sub
+   i32.shl
+   i32.add
+   i32.const 1
+   i32.sub
+  else
+   local.get $size
+  end
+  return
+ )
+ (func $~lib/rt/tlsf/searchBlock (param $root i32) (param $size i32) (result i32)
+  (local $fl i32)
+  (local $sl i32)
+  (local $requestSize i32)
+  (local $root|5 i32)
+  (local $fl|6 i32)
+  (local $slMap i32)
+  (local $head i32)
+  (local $flMap i32)
+  (local $root|10 i32)
+  (local $fl|11 i32)
+  (local $root|12 i32)
+  (local $fl|13 i32)
+  (local $sl|14 i32)
+  (local $root|15 i32)
+  (local $fl|16 i32)
+  (local $sl|17 i32)
+  local.get $size
+  i32.const 256
+  i32.lt_u
+  if
+   i32.const 0
+   local.set $fl
+   local.get $size
+   i32.const 4
+   i32.shr_u
+   local.set $sl
+  else
+   local.get $size
+   call $~lib/rt/tlsf/roundSize
+   local.set $requestSize
+   i32.const 4
+   i32.const 8
+   i32.mul
+   i32.const 1
+   i32.sub
+   local.get $requestSize
+   i32.clz
+   i32.sub
+   local.set $fl
+   local.get $requestSize
+   local.get $fl
+   i32.const 4
+   i32.sub
+   i32.shr_u
+   i32.const 1
+   i32.const 4
+   i32.shl
+   i32.xor
+   local.set $sl
+   local.get $fl
+   i32.const 8
+   i32.const 1
+   i32.sub
+   i32.sub
+   local.set $fl
+  end
+  i32.const 1
+  drop
+  local.get $fl
+  i32.const 23
+  i32.lt_u
+  if (result i32)
+   local.get $sl
+   i32.const 16
+   i32.lt_u
+  else
+   i32.const 0
+  end
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 334
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  block $~lib/rt/tlsf/GETSL|inlined.2 (result i32)
+   local.get $root
+   local.set $root|5
+   local.get $fl
+   local.set $fl|6
+   local.get $root|5
+   local.get $fl|6
+   i32.const 2
+   i32.shl
+   i32.add
+   i32.load offset=4
+   br $~lib/rt/tlsf/GETSL|inlined.2
+  end
+  i32.const 0
+  i32.const -1
+  i32.xor
+  local.get $sl
+  i32.shl
+  i32.and
+  local.set $slMap
+  i32.const 0
+  local.set $head
+  local.get $slMap
+  i32.eqz
+  if
+   local.get $root
+   call $~lib/rt/tlsf/Root#get:flMap
+   i32.const 0
+   i32.const -1
+   i32.xor
+   local.get $fl
+   i32.const 1
+   i32.add
+   i32.shl
+   i32.and
+   local.set $flMap
+   local.get $flMap
+   i32.eqz
+   if
+    i32.const 0
+    local.set $head
+   else
+    local.get $flMap
+    i32.ctz
+    local.set $fl
+    block $~lib/rt/tlsf/GETSL|inlined.3 (result i32)
+     local.get $root
+     local.set $root|10
+     local.get $fl
+     local.set $fl|11
+     local.get $root|10
+     local.get $fl|11
+     i32.const 2
+     i32.shl
+     i32.add
+     i32.load offset=4
+     br $~lib/rt/tlsf/GETSL|inlined.3
+    end
+    local.set $slMap
+    i32.const 1
+    drop
+    local.get $slMap
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 400
+     i32.const 347
+     i32.const 18
+     call $~lib/builtins/abort
+     unreachable
+    end
+    block $~lib/rt/tlsf/GETHEAD|inlined.2 (result i32)
+     local.get $root
+     local.set $root|12
+     local.get $fl
+     local.set $fl|13
+     local.get $slMap
+     i32.ctz
+     local.set $sl|14
+     local.get $root|12
+     local.get $fl|13
+     i32.const 4
+     i32.shl
+     local.get $sl|14
+     i32.add
+     i32.const 2
+     i32.shl
+     i32.add
+     i32.load offset=96
+     br $~lib/rt/tlsf/GETHEAD|inlined.2
+    end
+    local.set $head
+   end
+  else
+   block $~lib/rt/tlsf/GETHEAD|inlined.3 (result i32)
+    local.get $root
+    local.set $root|15
+    local.get $fl
+    local.set $fl|16
+    local.get $slMap
+    i32.ctz
+    local.set $sl|17
+    local.get $root|15
+    local.get $fl|16
+    i32.const 4
+    i32.shl
+    local.get $sl|17
+    i32.add
+    i32.const 2
+    i32.shl
+    i32.add
+    i32.load offset=96
+    br $~lib/rt/tlsf/GETHEAD|inlined.3
+   end
+   local.set $head
+  end
+  local.get $head
+  return
+ )
+ (func $~lib/rt/tlsf/growMemory (param $root i32) (param $size i32)
+  (local $pagesBefore i32)
+  (local $root|3 i32)
+  (local $pagesNeeded i32)
+  (local $5 i32)
+  (local $6 i32)
+  (local $pagesWanted i32)
+  (local $pagesAfter i32)
+  i32.const 0
+  drop
+  local.get $size
+  i32.const 256
+  i32.ge_u
+  if
+   local.get $size
+   call $~lib/rt/tlsf/roundSize
+   local.set $size
+  end
+  memory.size
+  local.set $pagesBefore
+  local.get $size
+  i32.const 4
+  local.get $pagesBefore
+  i32.const 16
+  i32.shl
+  i32.const 4
+  i32.sub
+  block $~lib/rt/tlsf/GETTAIL|inlined.1 (result i32)
+   local.get $root
+   local.set $root|3
+   local.get $root|3
+   i32.load offset=1568
+   br $~lib/rt/tlsf/GETTAIL|inlined.1
+  end
+  i32.ne
+  i32.shl
+  i32.add
+  local.set $size
+  local.get $size
+  i32.const 65535
+  i32.add
+  i32.const 65535
+  i32.const -1
+  i32.xor
+  i32.and
+  i32.const 16
+  i32.shr_u
+  local.set $pagesNeeded
+  local.get $pagesBefore
+  local.tee $5
+  local.get $pagesNeeded
+  local.tee $6
+  local.get $5
+  local.get $6
+  i32.gt_s
+  select
+  local.set $pagesWanted
+  local.get $pagesWanted
+  memory.grow
+  i32.const 0
+  i32.lt_s
+  if
+   local.get $pagesNeeded
+   memory.grow
+   i32.const 0
+   i32.lt_s
+   if
+    unreachable
+   end
+  end
+  memory.size
+  local.set $pagesAfter
+  local.get $root
+  local.get $pagesBefore
+  i32.const 16
+  i32.shl
+  local.get $pagesAfter
+  i64.extend_i32_s
+  i64.const 16
+  i64.shl
+  call $~lib/rt/tlsf/addMemory
+  drop
+ )
+ (func $~lib/rt/tlsf/prepareBlock (param $root i32) (param $block i32) (param $size i32)
+  (local $blockInfo i32)
+  (local $remaining i32)
+  (local $spare i32)
+  (local $block|6 i32)
+  (local $block|7 i32)
+  local.get $block
+  call $~lib/rt/common/BLOCK#get:mmInfo
+  local.set $blockInfo
+  i32.const 1
+  drop
+  local.get $size
+  i32.const 4
+  i32.add
+  i32.const 15
+  i32.and
+  i32.eqz
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 361
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $blockInfo
+  i32.const 3
+  i32.const -1
+  i32.xor
+  i32.and
+  local.get $size
+  i32.sub
+  local.set $remaining
+  local.get $remaining
+  i32.const 4
+  i32.const 12
+  i32.add
+  i32.ge_u
+  if
+   local.get $block
+   local.get $size
+   local.get $blockInfo
+   i32.const 2
+   i32.and
+   i32.or
+   call $~lib/rt/common/BLOCK#set:mmInfo
+   local.get $block
+   i32.const 4
+   i32.add
+   local.get $size
+   i32.add
+   local.set $spare
+   local.get $spare
+   local.get $remaining
+   i32.const 4
+   i32.sub
+   i32.const 1
+   i32.or
+   call $~lib/rt/common/BLOCK#set:mmInfo
+   local.get $root
+   local.get $spare
+   call $~lib/rt/tlsf/insertBlock
+  else
+   local.get $block
+   local.get $blockInfo
+   i32.const 1
+   i32.const -1
+   i32.xor
+   i32.and
+   call $~lib/rt/common/BLOCK#set:mmInfo
+   block $~lib/rt/tlsf/GETRIGHT|inlined.3 (result i32)
+    local.get $block
+    local.set $block|7
+    local.get $block|7
+    i32.const 4
+    i32.add
+    local.get $block|7
+    call $~lib/rt/common/BLOCK#get:mmInfo
+    i32.const 3
+    i32.const -1
+    i32.xor
+    i32.and
+    i32.add
+    br $~lib/rt/tlsf/GETRIGHT|inlined.3
+   end
+   block $~lib/rt/tlsf/GETRIGHT|inlined.2 (result i32)
+    local.get $block
+    local.set $block|6
+    local.get $block|6
+    i32.const 4
+    i32.add
+    local.get $block|6
+    call $~lib/rt/common/BLOCK#get:mmInfo
+    i32.const 3
+    i32.const -1
+    i32.xor
+    i32.and
+    i32.add
+    br $~lib/rt/tlsf/GETRIGHT|inlined.2
+   end
+   call $~lib/rt/common/BLOCK#get:mmInfo
+   i32.const 2
+   i32.const -1
+   i32.xor
+   i32.and
+   call $~lib/rt/common/BLOCK#set:mmInfo
+  end
+ )
+ (func $~lib/rt/tlsf/allocateBlock (param $root i32) (param $size i32) (result i32)
+  (local $payloadSize i32)
+  (local $block i32)
+  local.get $size
+  call $~lib/rt/tlsf/prepareSize
+  local.set $payloadSize
+  local.get $root
+  local.get $payloadSize
+  call $~lib/rt/tlsf/searchBlock
+  local.set $block
+  local.get $block
+  i32.eqz
+  if
+   local.get $root
+   local.get $payloadSize
+   call $~lib/rt/tlsf/growMemory
+   local.get $root
+   local.get $payloadSize
+   call $~lib/rt/tlsf/searchBlock
+   local.set $block
+   i32.const 1
+   drop
+   local.get $block
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 400
+    i32.const 499
+    i32.const 16
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  i32.const 1
+  drop
+  local.get $block
+  call $~lib/rt/common/BLOCK#get:mmInfo
+  i32.const 3
+  i32.const -1
+  i32.xor
+  i32.and
+  local.get $payloadSize
+  i32.ge_u
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 400
+   i32.const 501
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $root
+  local.get $block
+  call $~lib/rt/tlsf/removeBlock
+  local.get $root
+  local.get $block
+  local.get $payloadSize
+  call $~lib/rt/tlsf/prepareBlock
+  i32.const 0
+  drop
+  local.get $block
+  return
+ )
+ (func $~lib/rt/tlsf/__alloc (param $size i32) (result i32)
+  global.get $~lib/rt/tlsf/ROOT
+  i32.eqz
+  if
+   call $~lib/rt/tlsf/initialize
+  end
+  global.get $~lib/rt/tlsf/ROOT
+  local.get $size
+  call $~lib/rt/tlsf/allocateBlock
+  i32.const 4
+  i32.add
+  return
+ )
+ (func $~lib/rt/itcms/Object#set:rtId (param $this i32) (param $rtId i32)
+  local.get $this
+  local.get $rtId
+  i32.store offset=12
+ )
+ (func $~lib/rt/itcms/Object#set:rtSize (param $this i32) (param $rtSize i32)
+  local.get $this
+  local.get $rtSize
+  i32.store offset=16
+ )
+ (func $~lib/rt/itcms/__new (param $size i32) (param $id i32) (result i32)
+  (local $obj i32)
+  (local $ptr i32)
+  local.get $size
+  i32.const 1073741804
+  i32.ge_u
+  if
+   i32.const 64
+   i32.const 128
+   i32.const 261
+   i32.const 31
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/rt/itcms/total
+  global.get $~lib/rt/itcms/threshold
+  i32.ge_u
+  if
+   call $~lib/rt/itcms/interrupt
+  end
+  i32.const 16
+  local.get $size
+  i32.add
+  call $~lib/rt/tlsf/__alloc
+  i32.const 4
+  i32.sub
+  local.set $obj
+  local.get $obj
+  local.get $id
+  call $~lib/rt/itcms/Object#set:rtId
+  local.get $obj
+  local.get $size
+  call $~lib/rt/itcms/Object#set:rtSize
+  local.get $obj
+  global.get $~lib/rt/itcms/fromSpace
+  global.get $~lib/rt/itcms/white
+  call $~lib/rt/itcms/Object#linkTo
+  global.get $~lib/rt/itcms/total
+  local.get $obj
+  call $~lib/rt/itcms/Object#get:size
+  i32.add
+  global.set $~lib/rt/itcms/total
+  local.get $obj
+  i32.const 20
+  i32.add
+  local.set $ptr
+  local.get $ptr
+  i32.const 0
+  local.get $size
+  memory.fill
+  local.get $ptr
+  return
+ )
+ (func $features/tail-calls/maybeBox (param $x i32) (result i32)
+  local.get $x
+  if (result i32)
+   i32.const 0
+   call $features/tail-calls/Box#constructor
+  else
+   i32.const 0
+  end
+  return
+ )
+ (func $features/tail-calls/nullable (param $x i32) (result i32)
+  local.get $x
+  return_call $features/tail-calls/maybeBox
+ )
+ (func $features/tail-calls/maybeInvoke (param $fn i32) (param $x i32) (result i32)
+  local.get $x
+  i32.const 1
+  global.set $~argumentsLength
+  local.get $fn
+  i32.load
+  return_call_indirect (type $0)
+ )
+ (func $~lib/rt/__visit_globals (param $0 i32)
+  (local $1 i32)
+  i32.const 256
+  local.get $0
+  call $~lib/rt/itcms/__visit
+  i32.const 64
+  local.get $0
+  call $~lib/rt/itcms/__visit
+ )
+ (func $~lib/arraybuffer/ArrayBufferView~visit (param $0 i32) (param $1 i32)
+  (local $2 i32)
+  local.get $0
+  local.get $1
+  call $~lib/object/Object~visit
+  local.get $0
+  i32.load
+  local.get $1
+  call $~lib/rt/itcms/__visit
+ )
+ (func $~lib/object/Object~visit (param $0 i32) (param $1 i32)
+ )
+ (func $~lib/function/Function<%28i32%29=>i32>#get:_env (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=4
+ )
+ (func $~lib/function/Function<%28i32%29=>i32>~visit (param $0 i32) (param $1 i32)
+  local.get $0
+  local.get $1
+  call $~lib/object/Object~visit
+  local.get $0
+  local.get $1
+  call $~lib/function/Function<%28i32%29=>i32>#__visit
+ )
+ (func $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>#get:_env (param $this i32) (result i32)
+  local.get $this
+  i32.load offset=4
+ )
+ (func $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>~visit (param $0 i32) (param $1 i32)
+  local.get $0
+  local.get $1
+  call $~lib/object/Object~visit
+  local.get $0
+  local.get $1
+  call $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>#__visit
+ )
+ (func $~lib/rt/__visit_members (param $0 i32) (param $1 i32)
+  block $invalid
+   block $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>
+    block $features/tail-calls/Box
+     block $~lib/function/Function<%28i32%29=>i32>
+      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
+          br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $~lib/function/Function<%28i32%29=>i32> $features/tail-calls/Box $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null> $invalid
+         end
+         return
+        end
+        return
+       end
+       return
+      end
+      local.get $0
+      local.get $1
+      call $~lib/arraybuffer/ArrayBufferView~visit
+      return
+     end
+     local.get $0
+     local.get $1
+     call $~lib/function/Function<%28i32%29=>i32>~visit
+     return
+    end
+    return
+   end
+   local.get $0
+   local.get $1
+   call $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>~visit
+   return
+  end
+  unreachable
+ )
+ (func $~start
+  memory.size
+  i32.const 16
+  i32.shl
+  global.get $~lib/memory/__heap_base
+  i32.sub
+  i32.const 1
+  i32.shr_u
+  global.set $~lib/rt/itcms/threshold
+  i32.const 176
+  call $~lib/rt/itcms/initLazy
+  global.set $~lib/rt/itcms/pinSpace
+  i32.const 208
+  call $~lib/rt/itcms/initLazy
+  global.set $~lib/rt/itcms/toSpace
+  i32.const 352
+  call $~lib/rt/itcms/initLazy
+  global.set $~lib/rt/itcms/fromSpace
+ )
+ (func $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__data_end
+  i32.lt_s
+  if
+   i32.const 33312
+   i32.const 33360
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+ )
+ (func $features/tail-calls/indirect (param $x i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  i32.const 32
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store
+  local.get $1
+  local.get $x
+  return_call $features/tail-calls/invoke
+ )
+ (func $features/tail-calls/convertedIndirect (param $x i32) (result i64)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  i32.const 32
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store
+  local.get $1
+  local.get $x
+  return_call $features/tail-calls/widenInvoke
+ )
+ (func $features/tail-calls/Box#constructor (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
+  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
+  end
+  global.get $~lib/memory/__stack_pointer
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store offset=4
+  local.get $1
+  call $~lib/object/Object#constructor
+  local.tee $this
+  i32.store
+  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 $features/tail-calls/nullableIndirect (param $x i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  i32.const 464
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  local.get $1
+  i32.store
+  local.get $1
+  local.get $x
+  return_call $features/tail-calls/maybeInvoke
+ )
+ (func $~lib/function/Function<%28i32%29=>i32>#__visit (param $this i32) (param $cookie i32)
+  (local $2 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  local.get $this
+  local.set $2
+  global.get $~lib/memory/__stack_pointer
+  local.get $2
+  i32.store
+  local.get $2
+  call $~lib/function/Function<%28i32%29=>i32>#get:_env
+  local.get $cookie
+  call $~lib/rt/itcms/__visit
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+ )
+ (func $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>#__visit (param $this i32) (param $cookie i32)
+  (local $2 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  local.get $this
+  local.set $2
+  global.get $~lib/memory/__stack_pointer
+  local.get $2
+  i32.store
+  local.get $2
+  call $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>#get:_env
+  local.get $cookie
+  call $~lib/rt/itcms/__visit
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+ )
+ (func $~lib/object/Object#constructor (param $this i32) (result i32)
+  (local $1 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  call $~stack_check
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  local.get $this
+  i32.eqz
+  if
+   global.get $~lib/memory/__stack_pointer
+   i32.const 0
+   i32.const 0
+   call $~lib/rt/itcms/__new
+   local.tee $this
+   i32.store
+  end
+  local.get $this
+  local.set $1
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+  local.get $1
+ )
+)
diff --git a/tests/compiler/features/tail-calls.json b/tests/compiler/features/tail-calls.json
new file mode 100644
index 0000000000..ba47225711
--- /dev/null
+++ b/tests/compiler/features/tail-calls.json
@@ -0,0 +1,6 @@
+{
+  "features": [
+    "tail-calls"
+  ],
+  "skipInstantiate": true
+}
diff --git a/tests/compiler/features/tail-calls.release.wat b/tests/compiler/features/tail-calls.release.wat
new file mode 100644
index 0000000000..065dfd2182
--- /dev/null
+++ b/tests/compiler/features/tail-calls.release.wat
@@ -0,0 +1,1649 @@
+(module
+ (type $0 (func (param i32) (result i32)))
+ (type $1 (func))
+ (type $2 (func (param i32)))
+ (type $3 (func (param i32) (result i64)))
+ (type $4 (func (param i32 i32)))
+ (type $5 (func (param i32 i32 i32 i32)))
+ (type $6 (func (param i32 i32 i64)))
+ (type $7 (func (result i32)))
+ (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
+ (global $~lib/rt/itcms/total (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/threshold (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/state (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/visitCount (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/pinSpace (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/iter (mut i32) (i32.const 0))
+ (global $~lib/rt/itcms/toSpace (mut i32) (i32.const 0))
+ (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 34304))
+ (memory $0 1)
+ (data $0 (i32.const 1036) "\1c")
+ (data $0.1 (i32.const 1048) "\04\00\00\00\08\00\00\00\01")
+ (data $1 (i32.const 1068) "<")
+ (data $1.1 (i32.const 1080) "\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")
+ (data $2 (i32.const 1132) "<")
+ (data $2.1 (i32.const 1144) "\02\00\00\00 \00\00\00~\00l\00i\00b\00/\00r\00t\00/\00i\00t\00c\00m\00s\00.\00t\00s")
+ (data $5 (i32.const 1260) "<")
+ (data $5.1 (i32.const 1272) "\02\00\00\00$\00\00\00I\00n\00d\00e\00x\00 \00o\00u\00t\00 \00o\00f\00 \00r\00a\00n\00g\00e")
+ (data $6 (i32.const 1324) ",")
+ (data $6.1 (i32.const 1336) "\02\00\00\00\14\00\00\00~\00l\00i\00b\00/\00r\00t\00.\00t\00s")
+ (data $8 (i32.const 1404) "<")
+ (data $8.1 (i32.const 1416) "\02\00\00\00\1e\00\00\00~\00l\00i\00b\00/\00r\00t\00/\00t\00l\00s\00f\00.\00t\00s")
+ (data $9 (i32.const 1468) "\1c")
+ (data $9.1 (i32.const 1480) "\06\00\00\00\08\00\00\00\02")
+ (data $10 (i32.const 1504) "\07\00\00\00 \00\00\00 \00\00\00 ")
+ (data $10.1 (i32.const 1528) " ")
+ (table $0 3 3 funcref)
+ (elem $0 (i32.const 1) $features/tail-calls/inc $features/tail-calls/maybeBox)
+ (export "direct" (func $features/tail-calls/inc))
+ (export "directVoid" (func $features/tail-calls/directVoid))
+ (export "indirect" (func $features/tail-calls/indirect))
+ (export "converted" (func $features/tail-calls/converted))
+ (export "convertedIndirect" (func $features/tail-calls/convertedIndirect))
+ (export "nullable" (func $features/tail-calls/nullable))
+ (export "nullableIndirect" (func $features/tail-calls/nullableIndirect))
+ (export "memory" (memory $0))
+ (start $~start)
+ (func $features/tail-calls/inc (param $0 i32) (result i32)
+  local.get $0
+  i32.const 1
+  i32.add
+ )
+ (func $features/tail-calls/directVoid
+ )
+ (func $features/tail-calls/converted (param $0 i32) (result i64)
+  local.get $0
+  i32.const 1
+  i32.add
+  i64.extend_i32_s
+ )
+ (func $~lib/rt/itcms/visitRoots
+  (local $0 i32)
+  (local $1 i32)
+  i32.const 1280
+  call $~lib/rt/itcms/__visit
+  i32.const 1088
+  call $~lib/rt/itcms/__visit
+  global.get $~lib/rt/itcms/pinSpace
+  local.tee $1
+  i32.load offset=4
+  i32.const -4
+  i32.and
+  local.set $0
+  loop $while-continue|0
+   local.get $0
+   local.get $1
+   i32.ne
+   if
+    local.get $0
+    i32.load offset=4
+    i32.const 3
+    i32.and
+    i32.const 3
+    i32.ne
+    if
+     i32.const 0
+     i32.const 1152
+     i32.const 160
+     i32.const 16
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $0
+    i32.const 20
+    i32.add
+    call $~lib/rt/__visit_members
+    local.get $0
+    i32.load offset=4
+    i32.const -4
+    i32.and
+    local.set $0
+    br $while-continue|0
+   end
+  end
+ )
+ (func $~lib/rt/itcms/__visit (param $0 i32)
+  (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  local.get $0
+  i32.eqz
+  if
+   return
+  end
+  global.get $~lib/rt/itcms/white
+  local.get $0
+  i32.const 20
+  i32.sub
+  local.tee $1
+  i32.load offset=4
+  i32.const 3
+  i32.and
+  i32.eq
+  if
+   local.get $1
+   global.get $~lib/rt/itcms/iter
+   i32.eq
+   if
+    local.get $1
+    i32.load offset=8
+    local.tee $0
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 1152
+     i32.const 148
+     i32.const 30
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $0
+    global.set $~lib/rt/itcms/iter
+   end
+   block $__inlined_func$~lib/rt/itcms/Object#unlink$123
+    local.get $1
+    i32.load offset=4
+    i32.const -4
+    i32.and
+    local.tee $0
+    i32.eqz
+    if
+     local.get $1
+     i32.load offset=8
+     i32.eqz
+     local.get $1
+     i32.const 34304
+     i32.lt_u
+     i32.and
+     i32.eqz
+     if
+      i32.const 0
+      i32.const 1152
+      i32.const 128
+      i32.const 18
+      call $~lib/builtins/abort
+      unreachable
+     end
+     br $__inlined_func$~lib/rt/itcms/Object#unlink$123
+    end
+    local.get $1
+    i32.load offset=8
+    local.tee $2
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 1152
+     i32.const 132
+     i32.const 16
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $0
+    local.get $2
+    i32.store offset=8
+    local.get $2
+    local.get $0
+    local.get $2
+    i32.load offset=4
+    i32.const 3
+    i32.and
+    i32.or
+    i32.store offset=4
+   end
+   global.get $~lib/rt/itcms/toSpace
+   local.set $2
+   local.get $1
+   i32.load offset=12
+   local.tee $0
+   i32.const 2
+   i32.le_u
+   if (result i32)
+    i32.const 1
+   else
+    local.get $0
+    i32.const 1504
+    i32.load
+    i32.gt_u
+    if
+     i32.const 1280
+     i32.const 1344
+     i32.const 21
+     i32.const 28
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $0
+    i32.const 2
+    i32.shl
+    i32.const 1508
+    i32.add
+    i32.load
+    i32.const 32
+    i32.and
+   end
+   local.set $3
+   local.get $2
+   i32.load offset=8
+   local.set $0
+   local.get $1
+   global.get $~lib/rt/itcms/white
+   i32.eqz
+   i32.const 2
+   local.get $3
+   select
+   local.get $2
+   i32.or
+   i32.store offset=4
+   local.get $1
+   local.get $0
+   i32.store offset=8
+   local.get $0
+   local.get $1
+   local.get $0
+   i32.load offset=4
+   i32.const 3
+   i32.and
+   i32.or
+   i32.store offset=4
+   local.get $2
+   local.get $1
+   i32.store offset=8
+   global.get $~lib/rt/itcms/visitCount
+   i32.const 1
+   i32.add
+   global.set $~lib/rt/itcms/visitCount
+  end
+ )
+ (func $~lib/rt/tlsf/removeBlock (param $0 i32) (param $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
+  (local $5 i32)
+  local.get $1
+  i32.load
+  local.tee $3
+  i32.const 1
+  i32.and
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 268
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $3
+  i32.const -4
+  i32.and
+  local.tee $3
+  i32.const 12
+  i32.lt_u
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 270
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $3
+  i32.const 256
+  i32.lt_u
+  if (result i32)
+   local.get $3
+   i32.const 4
+   i32.shr_u
+  else
+   i32.const 31
+   i32.const 1073741820
+   local.get $3
+   local.get $3
+   i32.const 1073741820
+   i32.ge_u
+   select
+   local.tee $3
+   i32.clz
+   i32.sub
+   local.tee $4
+   i32.const 7
+   i32.sub
+   local.set $2
+   local.get $3
+   local.get $4
+   i32.const 4
+   i32.sub
+   i32.shr_u
+   i32.const 16
+   i32.xor
+  end
+  local.tee $3
+  i32.const 16
+  i32.lt_u
+  local.get $2
+  i32.const 23
+  i32.lt_u
+  i32.and
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 284
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $1
+  i32.load offset=8
+  local.set $5
+  local.get $1
+  i32.load offset=4
+  local.tee $4
+  if
+   local.get $4
+   local.get $5
+   i32.store offset=8
+  end
+  local.get $5
+  if
+   local.get $5
+   local.get $4
+   i32.store offset=4
+  end
+  local.get $1
+  local.get $0
+  local.get $2
+  i32.const 4
+  i32.shl
+  local.get $3
+  i32.add
+  i32.const 2
+  i32.shl
+  i32.add
+  local.tee $1
+  i32.load offset=96
+  i32.eq
+  if
+   local.get $1
+   local.get $5
+   i32.store offset=96
+   local.get $5
+   i32.eqz
+   if
+    local.get $0
+    local.get $2
+    i32.const 2
+    i32.shl
+    i32.add
+    local.tee $1
+    i32.load offset=4
+    i32.const -2
+    local.get $3
+    i32.rotl
+    i32.and
+    local.set $3
+    local.get $1
+    local.get $3
+    i32.store offset=4
+    local.get $3
+    i32.eqz
+    if
+     local.get $0
+     local.get $0
+     i32.load
+     i32.const -2
+     local.get $2
+     i32.rotl
+     i32.and
+     i32.store
+    end
+   end
+  end
+ )
+ (func $~lib/rt/tlsf/insertBlock (param $0 i32) (param $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
+  (local $5 i32)
+  (local $6 i32)
+  local.get $1
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 201
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $1
+  i32.load
+  local.tee $3
+  i32.const 1
+  i32.and
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 203
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $1
+  i32.const 4
+  i32.add
+  local.get $1
+  i32.load
+  i32.const -4
+  i32.and
+  i32.add
+  local.tee $4
+  i32.load
+  local.tee $2
+  i32.const 1
+  i32.and
+  if
+   local.get $0
+   local.get $4
+   call $~lib/rt/tlsf/removeBlock
+   local.get $1
+   local.get $3
+   i32.const 4
+   i32.add
+   local.get $2
+   i32.const -4
+   i32.and
+   i32.add
+   local.tee $3
+   i32.store
+   local.get $1
+   i32.const 4
+   i32.add
+   local.get $1
+   i32.load
+   i32.const -4
+   i32.and
+   i32.add
+   local.tee $4
+   i32.load
+   local.set $2
+  end
+  local.get $3
+  i32.const 2
+  i32.and
+  if
+   local.get $1
+   i32.const 4
+   i32.sub
+   i32.load
+   local.tee $1
+   i32.load
+   local.tee $6
+   i32.const 1
+   i32.and
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 1424
+    i32.const 221
+    i32.const 16
+    call $~lib/builtins/abort
+    unreachable
+   end
+   local.get $0
+   local.get $1
+   call $~lib/rt/tlsf/removeBlock
+   local.get $1
+   local.get $6
+   i32.const 4
+   i32.add
+   local.get $3
+   i32.const -4
+   i32.and
+   i32.add
+   local.tee $3
+   i32.store
+  end
+  local.get $4
+  local.get $2
+  i32.const 2
+  i32.or
+  i32.store
+  local.get $3
+  i32.const -4
+  i32.and
+  local.tee $2
+  i32.const 12
+  i32.lt_u
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 233
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $4
+  local.get $1
+  i32.const 4
+  i32.add
+  local.get $2
+  i32.add
+  i32.ne
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 234
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $4
+  i32.const 4
+  i32.sub
+  local.get $1
+  i32.store
+  local.get $2
+  i32.const 256
+  i32.lt_u
+  if (result i32)
+   local.get $2
+   i32.const 4
+   i32.shr_u
+  else
+   i32.const 31
+   i32.const 1073741820
+   local.get $2
+   local.get $2
+   i32.const 1073741820
+   i32.ge_u
+   select
+   local.tee $2
+   i32.clz
+   i32.sub
+   local.tee $3
+   i32.const 7
+   i32.sub
+   local.set $5
+   local.get $2
+   local.get $3
+   i32.const 4
+   i32.sub
+   i32.shr_u
+   i32.const 16
+   i32.xor
+  end
+  local.tee $2
+  i32.const 16
+  i32.lt_u
+  local.get $5
+  i32.const 23
+  i32.lt_u
+  i32.and
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 251
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $0
+  local.get $5
+  i32.const 4
+  i32.shl
+  local.get $2
+  i32.add
+  i32.const 2
+  i32.shl
+  i32.add
+  i32.load offset=96
+  local.set $3
+  local.get $1
+  i32.const 0
+  i32.store offset=4
+  local.get $1
+  local.get $3
+  i32.store offset=8
+  local.get $3
+  if
+   local.get $3
+   local.get $1
+   i32.store offset=4
+  end
+  local.get $0
+  local.get $5
+  i32.const 4
+  i32.shl
+  local.get $2
+  i32.add
+  i32.const 2
+  i32.shl
+  i32.add
+  local.get $1
+  i32.store offset=96
+  local.get $0
+  local.get $0
+  i32.load
+  i32.const 1
+  local.get $5
+  i32.shl
+  i32.or
+  i32.store
+  local.get $0
+  local.get $5
+  i32.const 2
+  i32.shl
+  i32.add
+  local.tee $0
+  local.get $0
+  i32.load offset=4
+  i32.const 1
+  local.get $2
+  i32.shl
+  i32.or
+  i32.store offset=4
+ )
+ (func $~lib/rt/tlsf/addMemory (param $0 i32) (param $1 i32) (param $2 i64)
+  (local $3 i32)
+  (local $4 i32)
+  (local $5 i32)
+  local.get $2
+  local.get $1
+  i64.extend_i32_u
+  i64.lt_u
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 382
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $1
+  i32.const 19
+  i32.add
+  i32.const -16
+  i32.and
+  i32.const 4
+  i32.sub
+  local.set $1
+  local.get $0
+  i32.load offset=1568
+  local.tee $3
+  if
+   local.get $3
+   i32.const 4
+   i32.add
+   local.get $1
+   i32.gt_u
+   if
+    i32.const 0
+    i32.const 1424
+    i32.const 389
+    i32.const 16
+    call $~lib/builtins/abort
+    unreachable
+   end
+   local.get $3
+   local.get $1
+   i32.const 16
+   i32.sub
+   local.tee $5
+   i32.eq
+   if
+    local.get $3
+    i32.load
+    local.set $4
+    local.get $5
+    local.set $1
+   end
+  else
+   local.get $0
+   i32.const 1572
+   i32.add
+   local.get $1
+   i32.gt_u
+   if
+    i32.const 0
+    i32.const 1424
+    i32.const 402
+    i32.const 5
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  local.get $2
+  i32.wrap_i64
+  i32.const -16
+  i32.and
+  local.get $1
+  i32.sub
+  local.tee $3
+  i32.const 20
+  i32.lt_u
+  if
+   return
+  end
+  local.get $1
+  local.get $4
+  i32.const 2
+  i32.and
+  local.get $3
+  i32.const 8
+  i32.sub
+  local.tee $3
+  i32.const 1
+  i32.or
+  i32.or
+  i32.store
+  local.get $1
+  i32.const 0
+  i32.store offset=4
+  local.get $1
+  i32.const 0
+  i32.store offset=8
+  local.get $1
+  i32.const 4
+  i32.add
+  local.get $3
+  i32.add
+  local.tee $3
+  i32.const 2
+  i32.store
+  local.get $0
+  local.get $3
+  i32.store offset=1568
+  local.get $0
+  local.get $1
+  call $~lib/rt/tlsf/insertBlock
+ )
+ (func $~lib/rt/tlsf/initialize
+  (local $0 i32)
+  (local $1 i32)
+  memory.size
+  local.tee $1
+  i32.const 0
+  i32.le_s
+  if (result i32)
+   i32.const 1
+   local.get $1
+   i32.sub
+   memory.grow
+   i32.const 0
+   i32.lt_s
+  else
+   i32.const 0
+  end
+  if
+   unreachable
+  end
+  i32.const 34304
+  i32.const 0
+  i32.store
+  i32.const 35872
+  i32.const 0
+  i32.store
+  loop $for-loop|0
+   local.get $0
+   i32.const 23
+   i32.lt_u
+   if
+    local.get $0
+    i32.const 2
+    i32.shl
+    i32.const 34304
+    i32.add
+    i32.const 0
+    i32.store offset=4
+    i32.const 0
+    local.set $1
+    loop $for-loop|1
+     local.get $1
+     i32.const 16
+     i32.lt_u
+     if
+      local.get $0
+      i32.const 4
+      i32.shl
+      local.get $1
+      i32.add
+      i32.const 2
+      i32.shl
+      i32.const 34304
+      i32.add
+      i32.const 0
+      i32.store offset=96
+      local.get $1
+      i32.const 1
+      i32.add
+      local.set $1
+      br $for-loop|1
+     end
+    end
+    local.get $0
+    i32.const 1
+    i32.add
+    local.set $0
+    br $for-loop|0
+   end
+  end
+  i32.const 34304
+  i32.const 35876
+  memory.size
+  i64.extend_i32_s
+  i64.const 16
+  i64.shl
+  call $~lib/rt/tlsf/addMemory
+  i32.const 34304
+  global.set $~lib/rt/tlsf/ROOT
+ )
+ (func $~lib/rt/itcms/step (result i32)
+  (local $0 i32)
+  (local $1 i32)
+  (local $2 i32)
+  block $break|0
+   block $case2|0
+    block $case1|0
+     block $case0|0
+      global.get $~lib/rt/itcms/state
+      br_table $case0|0 $case1|0 $case2|0 $break|0
+     end
+     i32.const 1
+     global.set $~lib/rt/itcms/state
+     i32.const 0
+     global.set $~lib/rt/itcms/visitCount
+     call $~lib/rt/itcms/visitRoots
+     global.get $~lib/rt/itcms/toSpace
+     global.set $~lib/rt/itcms/iter
+     global.get $~lib/rt/itcms/visitCount
+     return
+    end
+    global.get $~lib/rt/itcms/white
+    i32.eqz
+    local.set $1
+    global.get $~lib/rt/itcms/iter
+    i32.load offset=4
+    i32.const -4
+    i32.and
+    local.set $0
+    loop $while-continue|1
+     local.get $0
+     global.get $~lib/rt/itcms/toSpace
+     i32.ne
+     if
+      local.get $0
+      global.set $~lib/rt/itcms/iter
+      local.get $1
+      local.get $0
+      i32.load offset=4
+      local.tee $2
+      i32.const 3
+      i32.and
+      i32.ne
+      if
+       local.get $0
+       local.get $2
+       i32.const -4
+       i32.and
+       local.get $1
+       i32.or
+       i32.store offset=4
+       i32.const 0
+       global.set $~lib/rt/itcms/visitCount
+       local.get $0
+       i32.const 20
+       i32.add
+       call $~lib/rt/__visit_members
+       global.get $~lib/rt/itcms/visitCount
+       return
+      end
+      local.get $0
+      i32.load offset=4
+      i32.const -4
+      i32.and
+      local.set $0
+      br $while-continue|1
+     end
+    end
+    i32.const 0
+    global.set $~lib/rt/itcms/visitCount
+    call $~lib/rt/itcms/visitRoots
+    global.get $~lib/rt/itcms/toSpace
+    global.get $~lib/rt/itcms/iter
+    i32.load offset=4
+    i32.const -4
+    i32.and
+    i32.eq
+    if
+     global.get $~lib/memory/__stack_pointer
+     local.set $0
+     loop $while-continue|0
+      local.get $0
+      i32.const 34304
+      i32.lt_u
+      if
+       local.get $0
+       i32.load
+       call $~lib/rt/itcms/__visit
+       local.get $0
+       i32.const 4
+       i32.add
+       local.set $0
+       br $while-continue|0
+      end
+     end
+     global.get $~lib/rt/itcms/iter
+     i32.load offset=4
+     i32.const -4
+     i32.and
+     local.set $0
+     loop $while-continue|2
+      local.get $0
+      global.get $~lib/rt/itcms/toSpace
+      i32.ne
+      if
+       local.get $1
+       local.get $0
+       i32.load offset=4
+       local.tee $2
+       i32.const 3
+       i32.and
+       i32.ne
+       if
+        local.get $0
+        local.get $2
+        i32.const -4
+        i32.and
+        local.get $1
+        i32.or
+        i32.store offset=4
+        local.get $0
+        i32.const 20
+        i32.add
+        call $~lib/rt/__visit_members
+       end
+       local.get $0
+       i32.load offset=4
+       i32.const -4
+       i32.and
+       local.set $0
+       br $while-continue|2
+      end
+     end
+     global.get $~lib/rt/itcms/fromSpace
+     local.set $0
+     global.get $~lib/rt/itcms/toSpace
+     global.set $~lib/rt/itcms/fromSpace
+     local.get $0
+     global.set $~lib/rt/itcms/toSpace
+     local.get $1
+     global.set $~lib/rt/itcms/white
+     local.get $0
+     i32.load offset=4
+     i32.const -4
+     i32.and
+     global.set $~lib/rt/itcms/iter
+     i32.const 2
+     global.set $~lib/rt/itcms/state
+    end
+    global.get $~lib/rt/itcms/visitCount
+    return
+   end
+   global.get $~lib/rt/itcms/iter
+   local.tee $0
+   global.get $~lib/rt/itcms/toSpace
+   i32.ne
+   if
+    local.get $0
+    i32.load offset=4
+    local.tee $1
+    i32.const -4
+    i32.and
+    global.set $~lib/rt/itcms/iter
+    global.get $~lib/rt/itcms/white
+    i32.eqz
+    local.get $1
+    i32.const 3
+    i32.and
+    i32.ne
+    if
+     i32.const 0
+     i32.const 1152
+     i32.const 229
+     i32.const 20
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $0
+    i32.const 34304
+    i32.lt_u
+    if
+     local.get $0
+     i32.const 0
+     i32.store offset=4
+     local.get $0
+     i32.const 0
+     i32.store offset=8
+    else
+     global.get $~lib/rt/itcms/total
+     local.get $0
+     i32.load
+     i32.const -4
+     i32.and
+     i32.const 4
+     i32.add
+     i32.sub
+     global.set $~lib/rt/itcms/total
+     local.get $0
+     i32.const 4
+     i32.add
+     local.tee $0
+     i32.const 34304
+     i32.ge_u
+     if
+      global.get $~lib/rt/tlsf/ROOT
+      i32.eqz
+      if
+       call $~lib/rt/tlsf/initialize
+      end
+      global.get $~lib/rt/tlsf/ROOT
+      local.get $0
+      i32.const 4
+      i32.sub
+      local.set $2
+      local.get $0
+      i32.const 15
+      i32.and
+      i32.const 1
+      local.get $0
+      select
+      if (result i32)
+       i32.const 1
+      else
+       local.get $2
+       i32.load
+       i32.const 1
+       i32.and
+      end
+      if
+       i32.const 0
+       i32.const 1424
+       i32.const 562
+       i32.const 3
+       call $~lib/builtins/abort
+       unreachable
+      end
+      local.get $2
+      local.get $2
+      i32.load
+      i32.const 1
+      i32.or
+      i32.store
+      local.get $2
+      call $~lib/rt/tlsf/insertBlock
+     end
+    end
+    i32.const 10
+    return
+   end
+   global.get $~lib/rt/itcms/toSpace
+   global.get $~lib/rt/itcms/toSpace
+   i32.store offset=4
+   global.get $~lib/rt/itcms/toSpace
+   global.get $~lib/rt/itcms/toSpace
+   i32.store offset=8
+   i32.const 0
+   global.set $~lib/rt/itcms/state
+  end
+  i32.const 0
+ )
+ (func $~lib/rt/tlsf/searchBlock (param $0 i32) (result i32)
+  (local $1 i32)
+  (local $2 i32)
+  local.get $0
+  i32.load offset=4
+  i32.const -2
+  i32.and
+  local.tee $1
+  if (result i32)
+   local.get $0
+   local.get $1
+   i32.ctz
+   i32.const 2
+   i32.shl
+   i32.add
+   i32.load offset=96
+  else
+   local.get $0
+   i32.load
+   i32.const -2
+   i32.and
+   local.tee $1
+   if (result i32)
+    local.get $0
+    local.get $1
+    i32.ctz
+    local.tee $2
+    i32.const 2
+    i32.shl
+    i32.add
+    i32.load offset=4
+    local.tee $1
+    i32.eqz
+    if
+     i32.const 0
+     i32.const 1424
+     i32.const 347
+     i32.const 18
+     call $~lib/builtins/abort
+     unreachable
+    end
+    local.get $0
+    local.get $1
+    i32.ctz
+    local.get $2
+    i32.const 4
+    i32.shl
+    i32.add
+    i32.const 2
+    i32.shl
+    i32.add
+    i32.load offset=96
+   else
+    i32.const 0
+   end
+  end
+ )
+ (func $~lib/rt/itcms/__new (param $0 i32) (result i32)
+  (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
+  global.get $~lib/rt/itcms/total
+  global.get $~lib/rt/itcms/threshold
+  i32.ge_u
+  if
+   block $__inlined_func$~lib/rt/itcms/interrupt$72
+    i32.const 2048
+    local.set $1
+    loop $do-loop|0
+     local.get $1
+     call $~lib/rt/itcms/step
+     i32.sub
+     local.set $1
+     global.get $~lib/rt/itcms/state
+     i32.eqz
+     if
+      global.get $~lib/rt/itcms/total
+      i32.const 1
+      i32.shl
+      i32.const 1024
+      i32.add
+      global.set $~lib/rt/itcms/threshold
+      br $__inlined_func$~lib/rt/itcms/interrupt$72
+     end
+     local.get $1
+     i32.const 0
+     i32.gt_s
+     br_if $do-loop|0
+    end
+    global.get $~lib/rt/itcms/total
+    global.get $~lib/rt/itcms/total
+    global.get $~lib/rt/itcms/threshold
+    i32.sub
+    i32.const 1024
+    i32.lt_u
+    i32.const 10
+    i32.shl
+    i32.add
+    global.set $~lib/rt/itcms/threshold
+   end
+  end
+  global.get $~lib/rt/tlsf/ROOT
+  i32.eqz
+  if
+   call $~lib/rt/tlsf/initialize
+  end
+  global.get $~lib/rt/tlsf/ROOT
+  local.tee $2
+  call $~lib/rt/tlsf/searchBlock
+  local.tee $1
+  i32.eqz
+  if
+   memory.size
+   local.tee $1
+   i32.const 4
+   local.get $2
+   i32.load offset=1568
+   local.get $1
+   i32.const 16
+   i32.shl
+   i32.const 4
+   i32.sub
+   i32.ne
+   i32.shl
+   i32.const 65563
+   i32.add
+   i32.const -65536
+   i32.and
+   i32.const 16
+   i32.shr_u
+   local.tee $3
+   local.get $1
+   local.get $3
+   i32.gt_s
+   select
+   memory.grow
+   i32.const 0
+   i32.lt_s
+   if
+    local.get $3
+    memory.grow
+    i32.const 0
+    i32.lt_s
+    if
+     unreachable
+    end
+   end
+   local.get $2
+   local.get $1
+   i32.const 16
+   i32.shl
+   memory.size
+   i64.extend_i32_s
+   i64.const 16
+   i64.shl
+   call $~lib/rt/tlsf/addMemory
+   local.get $2
+   call $~lib/rt/tlsf/searchBlock
+   local.tee $1
+   i32.eqz
+   if
+    i32.const 0
+    i32.const 1424
+    i32.const 499
+    i32.const 16
+    call $~lib/builtins/abort
+    unreachable
+   end
+  end
+  local.get $1
+  i32.load
+  i32.const -4
+  i32.and
+  i32.const 28
+  i32.lt_u
+  if
+   i32.const 0
+   i32.const 1424
+   i32.const 501
+   i32.const 14
+   call $~lib/builtins/abort
+   unreachable
+  end
+  local.get $2
+  local.get $1
+  call $~lib/rt/tlsf/removeBlock
+  local.get $1
+  i32.load
+  local.tee $3
+  i32.const -4
+  i32.and
+  i32.const 28
+  i32.sub
+  local.tee $4
+  i32.const 16
+  i32.ge_u
+  if
+   local.get $1
+   local.get $3
+   i32.const 2
+   i32.and
+   i32.const 28
+   i32.or
+   i32.store
+   local.get $1
+   i32.const 32
+   i32.add
+   local.tee $3
+   local.get $4
+   i32.const 4
+   i32.sub
+   i32.const 1
+   i32.or
+   i32.store
+   local.get $2
+   local.get $3
+   call $~lib/rt/tlsf/insertBlock
+  else
+   local.get $1
+   local.get $3
+   i32.const -2
+   i32.and
+   i32.store
+   local.get $1
+   i32.const 4
+   i32.add
+   local.get $1
+   i32.load
+   i32.const -4
+   i32.and
+   i32.add
+   local.tee $2
+   local.get $2
+   i32.load
+   i32.const -3
+   i32.and
+   i32.store
+  end
+  local.get $1
+  local.get $0
+  i32.store offset=12
+  local.get $1
+  i32.const 0
+  i32.store offset=16
+  global.get $~lib/rt/itcms/fromSpace
+  local.tee $0
+  i32.load offset=8
+  local.set $2
+  local.get $1
+  local.get $0
+  global.get $~lib/rt/itcms/white
+  i32.or
+  i32.store offset=4
+  local.get $1
+  local.get $2
+  i32.store offset=8
+  local.get $2
+  local.get $1
+  local.get $2
+  i32.load offset=4
+  i32.const 3
+  i32.and
+  i32.or
+  i32.store offset=4
+  local.get $0
+  local.get $1
+  i32.store offset=8
+  global.get $~lib/rt/itcms/total
+  local.get $1
+  i32.load
+  i32.const -4
+  i32.and
+  i32.const 4
+  i32.add
+  i32.add
+  global.set $~lib/rt/itcms/total
+  local.get $1
+  i32.const 20
+  i32.add
+  local.tee $0
+  i32.const 0
+  i32.const 0
+  memory.fill
+  local.get $0
+ )
+ (func $features/tail-calls/maybeBox (param $0 i32) (result i32)
+  (local $1 i32)
+  block $folding-inner0
+   local.get $0
+   if
+    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 1536
+    i32.lt_s
+    br_if $folding-inner0
+    global.get $~lib/memory/__stack_pointer
+    i64.const 0
+    i64.store
+    global.get $~lib/memory/__stack_pointer
+    i32.const 5
+    call $~lib/rt/itcms/__new
+    local.tee $0
+    i32.store
+    global.get $~lib/memory/__stack_pointer
+    global.get $~lib/memory/__stack_pointer
+    local.get $0
+    i32.store offset=4
+    global.get $~lib/memory/__stack_pointer
+    i32.const 4
+    i32.sub
+    global.set $~lib/memory/__stack_pointer
+    global.get $~lib/memory/__stack_pointer
+    i32.const 1536
+    i32.lt_s
+    br_if $folding-inner0
+    global.get $~lib/memory/__stack_pointer
+    i32.const 0
+    i32.store
+    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
+    end
+    global.get $~lib/memory/__stack_pointer
+    i32.const 4
+    i32.add
+    global.set $~lib/memory/__stack_pointer
+    local.get $0
+    i32.store
+    global.get $~lib/memory/__stack_pointer
+    i32.const 8
+    i32.add
+    global.set $~lib/memory/__stack_pointer
+   else
+    i32.const 0
+    local.set $0
+   end
+   local.get $0
+   return
+  end
+  i32.const 34336
+  i32.const 34384
+  i32.const 1
+  i32.const 1
+  call $~lib/builtins/abort
+  unreachable
+ )
+ (func $features/tail-calls/nullable (param $0 i32) (result i32)
+  local.get $0
+  return_call $features/tail-calls/maybeBox
+ )
+ (func $~lib/function/Function<%28i32%29=>i32>~visit (param $0 i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1536
+  i32.lt_s
+  if
+   i32.const 34336
+   i32.const 34384
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  global.get $~lib/memory/__stack_pointer
+  local.get $0
+  i32.store
+  local.get $0
+  i32.load offset=4
+  call $~lib/rt/itcms/__visit
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.add
+  global.set $~lib/memory/__stack_pointer
+ )
+ (func $~lib/rt/__visit_members (param $0 i32)
+  block $invalid
+   block $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null>
+    block $features/tail-calls/Box
+     block $~lib/function/Function<%28i32%29=>i32>
+      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
+          br_table $~lib/object/Object $~lib/arraybuffer/ArrayBuffer $~lib/string/String $~lib/arraybuffer/ArrayBufferView $~lib/function/Function<%28i32%29=>i32> $features/tail-calls/Box $~lib/function/Function<%28i32%29=>features/tail-calls/Box|null> $invalid
+         end
+         return
+        end
+        return
+       end
+       return
+      end
+      local.get $0
+      i32.load
+      call $~lib/rt/itcms/__visit
+      return
+     end
+     local.get $0
+     call $~lib/function/Function<%28i32%29=>i32>~visit
+     return
+    end
+    return
+   end
+   local.get $0
+   call $~lib/function/Function<%28i32%29=>i32>~visit
+   return
+  end
+  unreachable
+ )
+ (func $~start
+  memory.size
+  i32.const 16
+  i32.shl
+  i32.const 34304
+  i32.sub
+  i32.const 1
+  i32.shr_u
+  global.set $~lib/rt/itcms/threshold
+  i32.const 1204
+  i32.const 1200
+  i32.store
+  i32.const 1208
+  i32.const 1200
+  i32.store
+  i32.const 1200
+  global.set $~lib/rt/itcms/pinSpace
+  i32.const 1236
+  i32.const 1232
+  i32.store
+  i32.const 1240
+  i32.const 1232
+  i32.store
+  i32.const 1232
+  global.set $~lib/rt/itcms/toSpace
+  i32.const 1380
+  i32.const 1376
+  i32.store
+  i32.const 1384
+  i32.const 1376
+  i32.store
+  i32.const 1376
+  global.set $~lib/rt/itcms/fromSpace
+ )
+ (func $features/tail-calls/indirect (param $0 i32) (result i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1536
+  i32.lt_s
+  if
+   i32.const 34336
+   i32.const 34384
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1056
+  i32.store
+  local.get $0
+  i32.const 1056
+  i32.load
+  return_call_indirect (type $0)
+ )
+ (func $features/tail-calls/convertedIndirect (param $0 i32) (result i64)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1536
+  i32.lt_s
+  if
+   i32.const 34336
+   i32.const 34384
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1056
+  i32.store
+  local.get $0
+  i32.const 1056
+  i32.load
+  call_indirect (type $0)
+  i64.extend_i32_s
+ )
+ (func $features/tail-calls/nullableIndirect (param $0 i32) (result i32)
+  global.get $~lib/memory/__stack_pointer
+  i32.const 4
+  i32.sub
+  global.set $~lib/memory/__stack_pointer
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1536
+  i32.lt_s
+  if
+   i32.const 34336
+   i32.const 34384
+   i32.const 1
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  global.get $~lib/memory/__stack_pointer
+  i32.const 0
+  i32.store
+  global.get $~lib/memory/__stack_pointer
+  i32.const 1488
+  i32.store
+  local.get $0
+  i32.const 1488
+  i32.load
+  return_call_indirect (type $0)
+ )
+)
diff --git a/tests/compiler/features/tail-calls.ts b/tests/compiler/features/tail-calls.ts
new file mode 100644
index 0000000000..d820514541
--- /dev/null
+++ b/tests/compiler/features/tail-calls.ts
@@ -0,0 +1,51 @@
+function inc(x: i32): i32 {
+  return x + 1;
+}
+
+function noop(): void {}
+
+export function direct(x: i32): i32 {
+  return inc(x);
+}
+
+export function directVoid(): void {
+  return noop();
+}
+
+function invoke(fn: (x: i32) => i32, x: i32): i32 {
+  return fn(x);
+}
+
+export function indirect(x: i32): i32 {
+  return invoke(inc, x);
+}
+
+export function converted(x: i32): i64 {
+  return inc(x);
+}
+
+function widenInvoke(fn: (x: i32) => i32, x: i32): i64 {
+  return fn(x);
+}
+
+export function convertedIndirect(x: i32): i64 {
+  return widenInvoke(inc, x);
+}
+
+class Box {}
+
+function maybeBox(x: i32): Box | null {
+  return x ? new Box() : null;
+}
+
+function maybeInvoke(fn: (x: i32) => Box | null, x: i32): Box | null {
+  return fn(x);
+}
+
+export function nullable(x: i32): Box | null {
+  return maybeBox(x);
+}
+
+export function nullableIndirect(x: i32): Box | null {
+  return maybeInvoke(maybeBox, x);
+}
diff --git a/tests/features.json b/tests/features.json
index 5c47772500..f92c07759b 100644
--- a/tests/features.json
+++ b/tests/features.json
@@ -29,6 +29,13 @@
     "v8_flags": [
     ]
   },
+  "tail-calls": {
+    "asc_flags": [
+      "--enable tail-calls"
+    ],
+    "v8_flags": [
+    ]
+  },
   "simd": {
     "asc_flags": [
       "--enable simd"