diff --git a/cli/asc.js b/cli/asc.js
index 818408f6..1a6b02e6 100644
--- a/cli/asc.js
+++ b/cli/asc.js
@@ -414,7 +414,8 @@ exports.main = function main(argv, options, callback) {
   // Initialize default aliases
   assemblyscript.setGlobalAlias(compilerOptions, "Math", "NativeMath");
   assemblyscript.setGlobalAlias(compilerOptions, "Mathf", "NativeMathf");
-  assemblyscript.setGlobalAlias(compilerOptions, "abort", "~lib/env/abort"); // to disable: --use abort=
+  assemblyscript.setGlobalAlias(compilerOptions, "abort", "~lib/env/abort");
+  assemblyscript.setGlobalAlias(compilerOptions, "trace", "~lib/env/trace");
 
   // Add or override aliases if specified
   if (args.use) {
diff --git a/src/builtins.ts b/src/builtins.ts
index a22db6fa..6227410d 100644
--- a/src/builtins.ts
+++ b/src/builtins.ts
@@ -2700,6 +2700,7 @@ export function compileCall(
           }
         }
       }
+      compiler.currentType = Type.void;
       return exprs.length
         ? module.createBlock(null, exprs)
         : module.createNop();
diff --git a/src/program.ts b/src/program.ts
index debd1a50..4b53dacd 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -626,8 +626,8 @@ export class Program extends DiagnosticEmitter {
     }
 
     // register 'main' if present
-    if (this.elementsLookup.has("main")) {
-      let element = <Element>this.elementsLookup.get("main");
+    if (this.moduleLevelExports.has("main")) {
+      let element = (<ModuleExport>this.moduleLevelExports.get("main")).element;
       if (
         element.kind == ElementKind.FUNCTION_PROTOTYPE &&
         !(<FunctionPrototype>element).isAny(CommonFlags.GENERIC | CommonFlags.AMBIENT)
diff --git a/std/assembly/collector/itcm.ts b/std/assembly/collector/itcm.ts
index 691e34c9..71cdf23f 100644
--- a/std/assembly/collector/itcm.ts
+++ b/std/assembly/collector/itcm.ts
@@ -4,122 +4,15 @@
  * @module std/assembly/collector/itcm
  *//***/
 
-// Based on the concepts of Bach Le's μgc, see: https://github.com/bullno1/ugc
+// Largely based on the Bach Le's μgc, see: https://github.com/bullno1/ugc
+
+const TRACE = true;
 
 import {
   AL_MASK,
   MAX_SIZE_32
 } from "../internal/allocator";
 
-// ╒═══════════════ Managed object layout (32-bit) ════════════════╕
-//    3                   2                   1
-//  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0  bits
-// ├─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┼─┴─┴─┤      ┐
-// │                              next                       │  F  │ ◄─┐ = nextWithFlags
-// ├─────────────────────────────────────────────────────────┴─────┤   │ usize
-// │                              prev                             │ ◄─┘
-// ╞═══════════════════════════════════════════════════════════════╡ SIZE ┘
-// │                          ... data ...                         │
-// └───────────────────────────────────────────────────────────────┘
-// F: flags
-
-/** Managed object flags. */
-namespace Flags {
-  /** Object is unreachable (so far). */
-  export var WHITE = 0;
-  /** Object is reachable. */
-  export var BLACK = 1;
-  /** Object is reachable but its children have not yet been scanned. */
-  export const GRAY = 2;
-  /** Mask to obtain just the flag bits. */
-  export const MASK = AL_MASK;
-}
-
-/** Represents a managed object in memory, consisting of a header followed by the object's data. */
-@unmanaged
-class ManagedObject {
-
-  /** Pointer to the next object with additional flags stored in the alignment bits. */
-  nextWithFlags: usize;
-
-  /** Pointer to the previous object. */
-  prev: ManagedObject;
-
-  /** Visitor function called with the data pointer (excl. header). */
-  visitFn: (obj: usize) => void;
-
-  /** Size of a managed object after alignment. */
-  static readonly SIZE: usize = (offsetof<ManagedObject>() + AL_MASK) & ~AL_MASK;
-
-  /** Gets the pointer to the next object in the list. */
-  get next(): ManagedObject {
-    return changetype<ManagedObject>(this.nextWithFlags & ~Flags.MASK);
-  }
-
-  /** Sets the pointer to the next object in the list. */
-  set next(obj: ManagedObject) {
-    this.nextWithFlags = changetype<usize>(obj) | (this.nextWithFlags & Flags.MASK);
-  }
-
-  /** Inserts an object to this list. */
-  insert(obj: ManagedObject): void {
-    var prev = this.prev;
-    obj.next = this;
-    obj.prev = prev;
-    prev.next = obj;
-    this.prev = obj;
-  }
-
-  /** Removes this object from its list. */
-  remove(): void {
-    var next = this.next;
-    var prev = this.prev;
-    next.prev = prev;
-    prev.next = next;
-  }
-
-  clear(): void {
-    this.nextWithFlags = changetype<usize>(this);
-    this.prev = this;
-  }
-
-  /** Tests if this object is white, that is unreachable (so far). */
-  get isWhite(): bool {
-    return (this.nextWithFlags & Flags.MASK) == Flags.WHITE;
-  }
-
-  /** Marks this object as white, that is unreachable (so far). */
-  makeWhite(): void {
-    this.nextWithFlags = (this.nextWithFlags & ~Flags.MASK) | Flags.WHITE;
-  }
-
-  /** Tests if this object is black, that is reachable. Root objects are always reachable. */
-  get isBlack(): bool {
-    return (this.nextWithFlags & Flags.MASK) == Flags.BLACK;
-  }
-
-  /** Marks this object as black, that is reachable. */
-  makeBlack(): void {
-    this.nextWithFlags = (this.nextWithFlags & ~Flags.MASK) | Flags.BLACK;
-  }
-
-  /** Tests if this object is gray, that is reachable with unscanned children. */
-  get isGray(): bool {
-    return (this.nextWithFlags & Flags.MASK) == Flags.GRAY;
-  }
-
-  /** Marks this object as gray, that is reachable with unscanned children. */
-  makeGray(): void {
-    if (this != iter) {
-      this.remove();
-      set2.insert(this);
-    } else {
-      iter = iter.prev;
-    }
-    this.nextWithFlags = (this.nextWithFlags & ~Flags.MASK) | Flags.GRAY;
-  }
-}
-
 /** Collector states. */
 const enum State {
   /** Not yet initialized. */
@@ -134,64 +27,164 @@ const enum State {
 
 /** Current collector state. */
 var state = State.INIT;
+/** Current white color value. */
+var white = 0;
 
 // From and to spaces
-var set1: ManagedObject;
-var set2: ManagedObject;
+var from: ManagedObject;
+var to: ManagedObject;
 var iter: ManagedObject;
 
+// ╒═══════════════ Managed object layout (32-bit) ════════════════╕
+//    3                   2                   1
+//  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0  bits
+// ├─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┼─┴─┴─┤      ┐
+// │                              next                       │  F  │ ◄─┐ = nextWithFlags
+// ├─────────────────────────────────────────────────────────┴─────┤   │ usize
+// │                              prev                             │ ◄─┘
+// ╞═══════════════════════════════════════════════════════════════╡ SIZE ┘
+// │                          ... data ...                         │
+// └───────────────────────────────────────────────────────────────┘
+// F: flags
+
+/** Represents a managed object in memory, consisting of a header followed by the object's data. */
+@unmanaged
+class ManagedObject {
+
+  /** Pointer to the next object with color flags stored in the alignment bits. */
+  nextWithColor: usize;
+
+  /** Pointer to the previous object. */
+  prev: ManagedObject;
+
+  /** Visitor function called with the payload reference. */
+  visitFn: (ref: usize) => void;
+
+  /** Size of a managed object after alignment. */
+  static readonly SIZE: usize = (offsetof<ManagedObject>() + AL_MASK) & ~AL_MASK;
+
+  /** Gets the pointer to the next object in the list. */
+  get next(): ManagedObject {
+    return changetype<ManagedObject>(this.nextWithColor & ~3);
+  }
+
+  /** Sets the pointer to the next object in the list. */
+  set next(obj: ManagedObject) {
+    this.nextWithColor = changetype<usize>(obj) | (this.nextWithColor & 3);
+  }
+
+  /** Gets this object's color. */
+  get color(): i32 {
+    return this.nextWithColor & 3;
+  }
+
+  /** Sets this object's color. */
+  set color(color: i32) {
+    this.nextWithColor = (this.nextWithColor & ~3) | color;
+  }
+
+  /** Inserts an object to this list. */
+  push(obj: ManagedObject): void {
+    var prev = this.prev;
+    trace("   push", 3, objToRef(prev), objToRef(obj), objToRef(this));
+    obj.next = this;
+    obj.prev = prev;
+    prev.next = obj;
+    this.prev = obj;
+  }
+
+  /** Unlinks this object from its list. */
+  unlink(): void {
+    var next = this.next;
+    var prev = this.prev;
+    if (TRACE) trace("   unlink", 3, objToRef(prev), objToRef(this), objToRef(next));
+    next.prev = prev;
+    prev.next = next;
+  }
+
+  clear(): void {
+    if (TRACE) trace("   clear", 1, objToRef(this));
+    this.nextWithColor = changetype<usize>(this);
+    this.prev = this;
+  }
+
+  /** Marks this object as gray, that is reachable with unscanned children. */
+  makeGray(): void {
+    if (TRACE) trace("   makeGray", 1, objToRef(this));
+    const gray = 2;
+    if (this == iter) iter = this.prev;
+    this.unlink();
+    to.push(this);
+    this.nextWithColor = (this.nextWithColor & ~3) | gray;
+  }
+}
+
+function markRoots(): void {
+  if (TRACE) trace("   markRoots");
+  gc.iterateRoots(function markRoot(ref: usize): void {
+    if (TRACE) trace("   markRoot", 1, ref);
+    if (ref) __gc_mark(ref);
+  });
+}
+
 /** Performs a single step according to the current state. */
 function step(): void {
   var obj: ManagedObject;
   switch (state) {
     case State.INIT: {
-      set1 = changetype<ManagedObject>(memory.allocate(ManagedObject.SIZE));
-      set1.clear();
-      set2 = changetype<ManagedObject>(memory.allocate(ManagedObject.SIZE));
-      set2.clear();
-      iter = set2;
+      if (TRACE) trace("gc~step/INIT");
+      from = changetype<ManagedObject>(memory.allocate(ManagedObject.SIZE));
+      from.visitFn = changetype<(ref: usize) => void>(<u32>-1); // would error
+      from.clear();
+      to = changetype<ManagedObject>(memory.allocate(ManagedObject.SIZE));
+      to.visitFn = changetype<(ref: usize) => void>(<u32>-1); // would error
+      to.clear();
+      iter = to;
+      state = State.IDLE;
+      if (TRACE) trace("gc~state = IDLE");
       // fall-through
     }
     case State.IDLE: {
-      // start by marking roots
-      gc.iterateRoots(function mark_root(ref: usize): void {
-        if (ref) {
-          let obj = changetype<ManagedObject>(ref - ManagedObject.SIZE);
-          obj.makeBlack();
-          obj.visitFn(ref);
-        }
-      });
+      if (TRACE) trace("gc~step/IDLE");
+      markRoots();
       state = State.MARK;
+      if (TRACE) trace("gc~state = MARK");
       break;
     }
     case State.MARK: {
       obj = iter.next;
-      if (obj != set2) {
+      if (obj !== to) {
+        if (TRACE) trace("gc~step/MARK iterate", 1, objToRef(obj));
         iter = obj;
-        obj.makeBlack();
-        obj.visitFn(changetype<usize>(obj) + ManagedObject.SIZE);
+        obj.color = <i32>!white;
+        obj.visitFn(objToRef(obj));
       } else {
+        if (TRACE) trace("gc~step/MARK finish");
+        markRoots();
         obj = iter.next;
-        if (obj == set2) {
-          let set1_ = set1;
-          set1 = set2;
-          set2 = set1_;
-          Flags.WHITE ^= 1;
-          Flags.BLACK ^= 1;
-          iter = set1.next;
+        if (obj === to) {
+          let prevFrom = from;
+          from = to;
+          to = prevFrom;
+          white = <i32>!white;
+          iter = prevFrom.next;
           state = State.SWEEP;
+          if (TRACE) trace("gc~state = SWEEP");
         }
       }
       break;
     }
     case State.SWEEP: {
       obj = iter;
-      if (obj !== set2) {
+      if (obj !== to) {
+        if (TRACE) trace("gc~step/SWEEP free", 1, objToRef(obj));
         iter = obj.next;
         memory.free(changetype<usize>(obj));
       } else {
-        set2.clear();
+        if (TRACE) trace("gc~step/SWEEP finish");
+        to.clear();
         state = State.IDLE;
+        if (TRACE) trace("gc~state = IDLE");
       }
       break;
     }
@@ -213,30 +206,33 @@ function step(): void {
   size: usize,
   visitFn: (ref: usize) => void
 ): usize {
-  assert(size <= MAX_SIZE_32 - ManagedObject.SIZE);
+  if (TRACE) trace("gc.allocate", 1, size);
+  if (size > MAX_SIZE_32 - ManagedObject.SIZE) unreachable();
+  step(); // also makes sure it's initialized
   var obj = changetype<ManagedObject>(memory.allocate(ManagedObject.SIZE + size));
-  obj.makeWhite();
   obj.visitFn = visitFn;
-  set1.insert(obj);
+  obj.color = white;
+  from.push(obj);
   return objToRef(obj);
 }
 
 /** Marks a reachable object. Called from the visitFn functions. */
 @global export function __gc_mark(ref: usize): void {
+  if (TRACE) trace("gc.mark", 1, ref);
   var obj = refToObj(ref);
-  if (state == State.SWEEP) return;
-  if (obj.isWhite) obj.makeGray();
+  if (obj.color == white) obj.makeGray();
 }
 
 /** Links a managed child object to its parent object. */
 @global export function __gc_link(parentRef: usize, childRef: usize): void {
+  if (TRACE) trace("gc.link", 2, parentRef, childRef);
   var parent = refToObj(parentRef);
-  var child = refToObj(childRef);
-  if (parent.isBlack && child.isWhite) parent.makeGray();
+  if (parent.color == <i32>!white && refToObj(childRef).color == white) parent.makeGray();
 }
 
 /** Performs a full garbage collection cycle. */
 @global export function __gc_collect(): void {
+  if (TRACE) trace("gc.collect");
   // begin collecting if not yet collecting
   switch (state) {
     case State.INIT:
diff --git a/std/assembly/env.ts b/std/assembly/env.ts
index f6da30e5..381e482c 100644
--- a/std/assembly/env.ts
+++ b/std/assembly/env.ts
@@ -1,7 +1,16 @@
-/** Environment abort function called where assertions evaluate to false / on throw. */
 declare function abort(
   message?: string | null,
   fileName?: string | null,
   lineNumber?: u32,
   columnNumber?: u32
 ): void;
+
+declare function trace(
+  message: string,
+  n?: i32,
+  a0?: f64,
+  a1?: f64,
+  a2?: f64,
+  a3?: f64,
+  a4?: f64
+): void;
diff --git a/std/assembly/gc.ts b/std/assembly/gc.ts
index fbe72028..7b83ae9e 100644
--- a/std/assembly/gc.ts
+++ b/std/assembly/gc.ts
@@ -9,19 +9,19 @@ export namespace gc {
   }
 
   export function mark(ref: usize): void {
-    if (isDefined(__gc_mark)) return __gc_mark(ref); // tslint:disable-line
+    if (isDefined(__gc_mark)) { __gc_mark(ref); return; } // tslint:disable-line
     WARNING("Calling 'gc.mark' requires a garbage collector to be present.");
     unreachable();
   }
 
   export function link(parentRef: usize, childRef: usize): void {
-    if (isDefined(__gc_link)) return __gc_link(parentRef, childRef); // tslint:disable-line
+    if (isDefined(__gc_link)) { __gc_link(parentRef, childRef); return; } // tslint:disable-line
     WARNING("Calling 'gc.link' requires a garbage collector to be present.");
     unreachable();
   }
 
   export function collect(): void {
-    if (isDefined(__gc_collect)) return __gc_collect(); // tslint:disable-line
+    if (isDefined(__gc_collect)) { __gc_collect(); return; } // tslint:disable-line
     WARNING("Calling 'gc.collect' requires a garbage collector to be present.");
     unreachable();
   }
diff --git a/std/assembly/index.d.ts b/std/assembly/index.d.ts
index 5777a0bc..0083c6c9 100644
--- a/std/assembly/index.d.ts
+++ b/std/assembly/index.d.ts
@@ -654,6 +654,9 @@ declare const Math: IMath<f64>;
 /** Alias of {@link NativeMathf} or {@link JSMath} respectively. Defaults to `NativeMathf`. */
 declare const Mathf: IMath<f32>;
 
+/** Environmental tracing function for debugging purposes. */
+declare function trace(msg: string, n?: i32, a0?: f64, a1?: f64, a2?: f64, a3?: f64, a4?: f64): void;
+
 // Decorators
 
 /** Annotates an element as a program global. */
diff --git a/tests/compiler.js b/tests/compiler.js
index 96da3280..d77ad7ff 100644
--- a/tests/compiler.js
+++ b/tests/compiler.js
@@ -153,16 +153,40 @@ tests.forEach(filename => {
 
       // Instantiate
       try {
+        let memory = new WebAssembly.Memory({ initial: 10 });
+        let exports = {};
+
+        function getString(ptr) {
+          if (!ptr) return "null";
+          var U32 = new Uint32Array(exports.memory ? exports.memory.buffer : memory.buffer);
+          var U16 = new Uint16Array(exports.memory ? exports.memory.buffer : memory.buffer);
+          var dataLength = U32[ptr >>> 2];
+          var dataOffset = (ptr + 4) >>> 1;
+          var dataRemain = dataLength;
+          var parts = [];
+          const chunkSize = 1024;
+          while (dataRemain > chunkSize) {
+            let last = U16[dataOffset + chunkSize - 1];
+            let size = last >= 0xD800 && last < 0xDC00 ? chunkSize - 1 : chunkSize;
+            let part = U16.subarray(dataOffset, dataOffset += size);
+            parts.push(String.fromCharCode.apply(String, part));
+            dataRemain -= size;
+          }
+          return parts.join("") + String.fromCharCode.apply(String, U16.subarray(dataOffset, dataOffset + dataRemain));
+        }
+
         let runTime = asc.measure(() => {
-          let exports = new WebAssembly.Instance(new WebAssembly.Module(stdout.toBuffer()), {
+          exports = new WebAssembly.Instance(new WebAssembly.Module(stdout.toBuffer()), {
             env: {
+              memory,
               abort: function(msg, file, line, column) {
-                console.log("abort called at " + line + ":" + column);
+                console.log(colorsUtil.red("  abort: " + getString(msg) + " at " + getString(file) + ":" + line + ":" + column));
+              },
+              trace: function(msg, n) {
+                console.log("  " + getString(msg) + (n ? " " : "") + Array.prototype.slice.call(arguments, 2, 2 + n).join(", "));
               },
               externalFunction: function() { },
-              externalConstant: 1,
-              logi: function(i) { console.log("logi: " + i); },
-              logf: function(f) { console.log("logf: " + f); }
+              externalConstant: 1
             },
             JSOp: {
               mod: function(a, b) { return a % b; }
@@ -188,10 +212,16 @@ tests.forEach(filename => {
               bar: function() {},
               baz: function() {},
               "var": 3
-            },
-          });
+            }
+          }).exports;
+          if (exports.main) {
+            console.log(colorsUtil.white("  [main]"));
+            var code = exports.main();
+            console.log(colorsUtil.white("  [exit " + code + "]\n"));
+          }
         });
         console.log("- " + colorsUtil.green("instantiate OK") + " (" + asc.formatTime(runTime) + ")");
+        console.log("\n  " + Object.keys(exports).map(key => "[" + (typeof exports[key]).substring(0, 3) + "] " + key).join("\n  "));
       } catch (e) {
         console.log("- " + colorsUtil.red("instantiate ERROR: ") + e.stack);
         failed = true;
diff --git a/tests/compiler/main.optimized.wat b/tests/compiler/main.optimized.wat
index 452f9eae..7a3b5019 100644
--- a/tests/compiler/main.optimized.wat
+++ b/tests/compiler/main.optimized.wat
@@ -2,11 +2,22 @@
  (type $iii (func (param i32 i32) (result i32)))
  (type $v (func))
  (global $main/code (mut i32) (i32.const 0))
+ (global $~started (mut i32) (i32.const 0))
  (memory $0 0)
  (export "memory" (memory $0))
  (export "main" (func $main/main))
- (start $start)
  (func $main/main (; 0 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
+  (if
+   (i32.eqz
+    (get_global $~started)
+   )
+   (block
+    (call $start)
+    (set_global $~started
+     (i32.const 1)
+    )
+   )
+  )
   (get_global $main/code)
  )
  (func $start (; 1 ;) (type $v)
diff --git a/tests/compiler/main.untouched.wat b/tests/compiler/main.untouched.wat
index d3e5c620..76d161e5 100644
--- a/tests/compiler/main.untouched.wat
+++ b/tests/compiler/main.untouched.wat
@@ -2,12 +2,23 @@
  (type $iii (func (param i32 i32) (result i32)))
  (type $v (func))
  (global $main/code (mut i32) (i32.const 0))
+ (global $~started (mut i32) (i32.const 0))
  (global $HEAP_BASE i32 (i32.const 8))
  (memory $0 0)
  (export "memory" (memory $0))
  (export "main" (func $main/main))
- (start $start)
  (func $main/main (; 0 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
+  (if
+   (i32.eqz
+    (get_global $~started)
+   )
+   (block
+    (call $start)
+    (set_global $~started
+     (i32.const 1)
+    )
+   )
+  )
   (get_global $main/code)
  )
  (func $start (; 1 ;) (type $v)
diff --git a/tests/compiler/std/gc.optimized.wat b/tests/compiler/std/gc.optimized.wat
index b1527fb1..91557c9f 100644
--- a/tests/compiler/std/gc.optimized.wat
+++ b/tests/compiler/std/gc.optimized.wat
@@ -1,30 +1,54 @@
 (module
  (type $iv (func (param i32)))
  (type $iii (func (param i32 i32) (result i32)))
- (type $iiiiv (func (param i32 i32 i32 i32)))
+ (type $iiFFFFFv (func (param i32 i32 f64 f64 f64 f64 f64)))
+ (type $v (func))
  (type $ii (func (param i32) (result i32)))
  (type $iiv (func (param i32 i32)))
- (type $v (func))
+ (type $iiiiv (func (param i32 i32 i32 i32)))
+ (type $i (func (result i32)))
+ (import "env" "trace" (func $~lib/env/trace (param i32 i32 f64 f64 f64 f64 f64)))
  (import "env" "abort" (func $~lib/env/abort (param i32 i32 i32 i32)))
  (global $~lib/allocator/arena/startOffset (mut i32) (i32.const 0))
  (global $~lib/allocator/arena/offset (mut i32) (i32.const 0))
  (global $~lib/collector/itcm/state (mut i32) (i32.const 0))
- (global $~lib/collector/itcm/set1 (mut i32) (i32.const 0))
- (global $~lib/collector/itcm/Flags.WHITE (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/white (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/from (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/to (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/iter (mut i32) (i32.const 0))
+ (global $~argc (mut i32) (i32.const 0))
  (global $std/gc/obj (mut i32) (i32.const 0))
  (global $std/gc/head (mut i32) (i32.const 0))
- (table 1 1 anyfunc)
- (elem (i32.const 0) $std/gc/MyObject_visit)
+ (global $~started (mut i32) (i32.const 0))
+ (table 2 2 anyfunc)
+ (elem (i32.const 0) $std/gc/MyObject_visit $~lib/collector/itcm/markRoots~markRoot|1)
  (memory $0 1)
- (data (i32.const 8) "\16\00\00\00~\00l\00i\00b\00/\00c\00o\00l\00l\00e\00c\00t\00o\00r\00/\00i\00t\00c\00m\00.\00t\00s")
- (data (i32.const 56) "\t\00\00\00s\00t\00d\00/\00g\00c\00.\00t\00s")
+ (data (i32.const 8) "\0b\00\00\00g\00c\00.\00a\00l\00l\00o\00c\00a\00t\00e")
+ (data (i32.const 36) "\0c\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00I\00N\00I\00T")
+ (data (i32.const 64) "\08\00\00\00 \00 \00 \00c\00l\00e\00a\00r")
+ (data (i32.const 84) "\0f\00\00\00g\00c\00~\00s\00t\00a\00t\00e\00 \00=\00 \00I\00D\00L\00E")
+ (data (i32.const 120) "\0c\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00I\00D\00L\00E")
+ (data (i32.const 148) "\0c\00\00\00 \00 \00 \00m\00a\00r\00k\00R\00o\00o\00t\00s")
+ (data (i32.const 176) "\0b\00\00\00 \00 \00 \00m\00a\00r\00k\00R\00o\00o\00t")
+ (data (i32.const 204) "\07\00\00\00g\00c\00.\00m\00a\00r\00k")
+ (data (i32.const 224) "\0b\00\00\00 \00 \00 \00m\00a\00k\00e\00G\00r\00a\00y")
+ (data (i32.const 252) "\t\00\00\00 \00 \00 \00u\00n\00l\00i\00n\00k")
+ (data (i32.const 276) "\07\00\00\00 \00 \00 \00p\00u\00s\00h")
+ (data (i32.const 296) "\0f\00\00\00g\00c\00~\00s\00t\00a\00t\00e\00 \00=\00 \00M\00A\00R\00K")
+ (data (i32.const 332) "\14\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00M\00A\00R\00K\00 \00i\00t\00e\00r\00a\00t\00e")
+ (data (i32.const 376) "\13\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00M\00A\00R\00K\00 \00f\00i\00n\00i\00s\00h")
+ (data (i32.const 420) "\10\00\00\00g\00c\00~\00s\00t\00a\00t\00e\00 \00=\00 \00S\00W\00E\00E\00P")
+ (data (i32.const 456) "\12\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00S\00W\00E\00E\00P\00 \00f\00r\00e\00e")
+ (data (i32.const 496) "\14\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00S\00W\00E\00E\00P\00 \00f\00i\00n\00i\00s\00h")
+ (data (i32.const 540) "\t\00\00\00s\00t\00d\00/\00g\00c\00.\00t\00s")
+ (data (i32.const 564) "\n\00\00\00g\00c\00.\00c\00o\00l\00l\00e\00c\00t")
  (export "memory" (memory $0))
  (export "table" (table $0))
- (start $start)
- (func $std/gc/MyObject_visit (; 1 ;) (type $iv) (param $0 i32)
+ (export "main" (func $std/gc/main))
+ (func $std/gc/MyObject_visit (; 2 ;) (type $iv) (param $0 i32)
   (nop)
  )
- (func $~lib/allocator/arena/__memory_allocate (; 2 ;) (type $ii) (param $0 i32) (result i32)
+ (func $~lib/allocator/arena/__memory_allocate (; 3 ;) (type $ii) (param $0 i32) (result i32)
   (local $1 i32)
   (local $2 i32)
   (local $3 i32)
@@ -110,26 +134,52 @@
   )
   (i32.const 0)
  )
- (func $~lib/memory/memory.allocate (; 3 ;) (type $ii) (param $0 i32) (result i32)
+ (func $~lib/memory/memory.allocate (; 4 ;) (type $ii) (param $0 i32) (result i32)
   (call $~lib/allocator/arena/__memory_allocate
    (get_local $0)
   )
  )
- (func $~lib/collector/itcm/ManagedObject#makeWhite (; 4 ;) (type $iv) (param $0 i32)
+ (func $~lib/collector/itcm/ManagedObject#clear (; 5 ;) (type $iv) (param $0 i32)
+  (call $~lib/env/trace
+   (i32.const 64)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (i32.add
+     (get_local $0)
+     (i32.const 16)
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
   (i32.store
    (get_local $0)
-   (i32.or
-    (i32.and
-     (i32.load
-      (get_local $0)
-     )
-     (i32.const -8)
-    )
-    (get_global $~lib/collector/itcm/Flags.WHITE)
-   )
+   (get_local $0)
+  )
+  (i32.store offset=4
+   (get_local $0)
+   (get_local $0)
   )
  )
- (func $~lib/collector/itcm/ManagedObject#set:next (; 5 ;) (type $iiv) (param $0 i32) (param $1 i32)
+ (func $~lib/collector/itcm/ManagedObject#get:color (; 6 ;) (type $ii) (param $0 i32) (result i32)
+  (i32.and
+   (i32.load
+    (get_local $0)
+   )
+   (i32.const 3)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#get:next (; 7 ;) (type $ii) (param $0 i32) (result i32)
+  (i32.and
+   (i32.load
+    (get_local $0)
+   )
+   (i32.const -4)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#set:next (; 8 ;) (type $iiv) (param $0 i32) (param $1 i32)
   (i32.store
    (get_local $0)
    (i32.or
@@ -138,18 +188,86 @@
      (i32.load
       (get_local $0)
      )
-     (i32.const 7)
+     (i32.const 3)
     )
    )
   )
  )
- (func $~lib/collector/itcm/ManagedObject#insert (; 6 ;) (type $iiv) (param $0 i32) (param $1 i32)
+ (func $~lib/collector/itcm/ManagedObject#unlink (; 9 ;) (type $iv) (param $0 i32)
+  (local $1 i32)
   (local $2 i32)
-  (set_local $2
-   (i32.load offset=4
+  (set_local $1
+   (call $~lib/collector/itcm/ManagedObject#get:next
     (get_local $0)
    )
   )
+  (call $~lib/env/trace
+   (i32.const 252)
+   (i32.const 3)
+   (f64.convert_u/i32
+    (i32.add
+     (tee_local $2
+      (i32.load offset=4
+       (get_local $0)
+      )
+     )
+     (i32.const 16)
+    )
+   )
+   (f64.convert_u/i32
+    (i32.add
+     (get_local $0)
+     (i32.const 16)
+    )
+   )
+   (f64.convert_u/i32
+    (i32.add
+     (get_local $1)
+     (i32.const 16)
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (i32.store offset=4
+   (get_local $1)
+   (get_local $2)
+  )
+  (call $~lib/collector/itcm/ManagedObject#set:next
+   (get_local $2)
+   (get_local $1)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#push (; 10 ;) (type $iiv) (param $0 i32) (param $1 i32)
+  (local $2 i32)
+  (call $~lib/env/trace
+   (i32.const 276)
+   (i32.const 3)
+   (f64.convert_u/i32
+    (i32.add
+     (tee_local $2
+      (i32.load offset=4
+       (get_local $0)
+      )
+     )
+     (i32.const 16)
+    )
+   )
+   (f64.convert_u/i32
+    (i32.add
+     (get_local $1)
+     (i32.const 16)
+    )
+   )
+   (f64.convert_u/i32
+    (i32.add
+     (get_local $0)
+     (i32.const 16)
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+  )
   (call $~lib/collector/itcm/ManagedObject#set:next
    (get_local $1)
    (get_local $0)
@@ -167,24 +285,414 @@
    (get_local $1)
   )
  )
- (func $~lib/collector/itcm/__gc_allocate (; 7 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
+ (func $~lib/collector/itcm/ManagedObject#makeGray (; 11 ;) (type $iv) (param $0 i32)
+  (call $~lib/env/trace
+   (i32.const 224)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (i32.add
+     (get_local $0)
+     (i32.const 16)
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (if
+   (i32.eq
+    (get_local $0)
+    (get_global $~lib/collector/itcm/iter)
+   )
+   (set_global $~lib/collector/itcm/iter
+    (i32.load offset=4
+     (get_local $0)
+    )
+   )
+  )
+  (call $~lib/collector/itcm/ManagedObject#unlink
+   (get_local $0)
+  )
+  (call $~lib/collector/itcm/ManagedObject#push
+   (get_global $~lib/collector/itcm/to)
+   (get_local $0)
+  )
+  (i32.store
+   (get_local $0)
+   (i32.or
+    (i32.and
+     (i32.load
+      (get_local $0)
+     )
+     (i32.const -4)
+    )
+    (i32.const 2)
+   )
+  )
+ )
+ (func $~lib/collector/itcm/__gc_mark (; 12 ;) (type $iv) (param $0 i32)
+  (local $1 i32)
+  (call $~lib/env/trace
+   (i32.const 204)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (get_local $0)
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (if
+   (i32.eq
+    (call $~lib/collector/itcm/ManagedObject#get:color
+     (tee_local $1
+      (i32.sub
+       (get_local $0)
+       (i32.const 16)
+      )
+     )
+    )
+    (get_global $~lib/collector/itcm/white)
+   )
+   (call $~lib/collector/itcm/ManagedObject#makeGray
+    (get_local $1)
+   )
+  )
+ )
+ (func $~lib/collector/itcm/markRoots~markRoot|1 (; 13 ;) (type $iv) (param $0 i32)
+  (call $~lib/env/trace
+   (i32.const 176)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (get_local $0)
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (if
+   (get_local $0)
+   (call $~lib/collector/itcm/__gc_mark
+    (get_local $0)
+   )
+  )
+ )
+ (func $~lib/collector/itcm/markRoots (; 14 ;) (type $v)
+  (call $~lib/env/trace
+   (i32.const 148)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call_indirect (type $iv)
+   (get_global $std/gc/obj)
+   (i32.const 1)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#set:color (; 15 ;) (type $iiv) (param $0 i32) (param $1 i32)
+  (i32.store
+   (get_local $0)
+   (i32.or
+    (i32.and
+     (i32.load
+      (get_local $0)
+     )
+     (i32.const -4)
+    )
+    (get_local $1)
+   )
+  )
+ )
+ (func $~lib/memory/memory.free (; 16 ;) (type $iv) (param $0 i32)
+  (call $std/gc/MyObject_visit
+   (get_local $0)
+  )
+ )
+ (func $~lib/collector/itcm/step (; 17 ;) (type $v)
+  (local $0 i32)
+  (block $break|0
+   (block $case3|0
+    (block $case2|0
+     (block $case1|0
+      (if
+       (tee_local $0
+        (get_global $~lib/collector/itcm/state)
+       )
+       (block
+        (block $tablify|0
+         (br_table $case1|0 $case2|0 $case3|0 $tablify|0
+          (i32.sub
+           (get_local $0)
+           (i32.const 1)
+          )
+         )
+        )
+        (br $break|0)
+       )
+      )
+      (call $~lib/env/trace
+       (i32.const 36)
+       (i32.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+      (set_global $~lib/collector/itcm/from
+       (call $~lib/memory/memory.allocate
+        (i32.const 16)
+       )
+      )
+      (i32.store offset=8
+       (get_global $~lib/collector/itcm/from)
+       (i32.const -1)
+      )
+      (call $~lib/collector/itcm/ManagedObject#clear
+       (get_global $~lib/collector/itcm/from)
+      )
+      (set_global $~lib/collector/itcm/to
+       (call $~lib/memory/memory.allocate
+        (i32.const 16)
+       )
+      )
+      (i32.store offset=8
+       (get_global $~lib/collector/itcm/to)
+       (i32.const -1)
+      )
+      (call $~lib/collector/itcm/ManagedObject#clear
+       (get_global $~lib/collector/itcm/to)
+      )
+      (set_global $~lib/collector/itcm/iter
+       (get_global $~lib/collector/itcm/to)
+      )
+      (set_global $~lib/collector/itcm/state
+       (i32.const 1)
+      )
+      (call $~lib/env/trace
+       (i32.const 84)
+       (i32.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+     )
+     (call $~lib/env/trace
+      (i32.const 120)
+      (i32.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+     )
+     (call $~lib/collector/itcm/markRoots)
+     (set_global $~lib/collector/itcm/state
+      (i32.const 2)
+     )
+     (call $~lib/env/trace
+      (i32.const 296)
+      (i32.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+     )
+     (br $break|0)
+    )
+    (if
+     (i32.ne
+      (tee_local $0
+       (call $~lib/collector/itcm/ManagedObject#get:next
+        (get_global $~lib/collector/itcm/iter)
+       )
+      )
+      (get_global $~lib/collector/itcm/to)
+     )
+     (block
+      (call $~lib/env/trace
+       (i32.const 332)
+       (i32.const 1)
+       (f64.convert_u/i32
+        (i32.add
+         (get_local $0)
+         (i32.const 16)
+        )
+       )
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+      (set_global $~lib/collector/itcm/iter
+       (get_local $0)
+      )
+      (call $~lib/collector/itcm/ManagedObject#set:color
+       (get_local $0)
+       (i32.eqz
+        (get_global $~lib/collector/itcm/white)
+       )
+      )
+      (set_global $~argc
+       (i32.const 1)
+      )
+      (call_indirect (type $iv)
+       (i32.add
+        (get_local $0)
+        (i32.const 16)
+       )
+       (i32.load offset=8
+        (get_local $0)
+       )
+      )
+     )
+     (block
+      (call $~lib/env/trace
+       (i32.const 376)
+       (i32.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+      (call $~lib/collector/itcm/markRoots)
+      (if
+       (i32.eq
+        (call $~lib/collector/itcm/ManagedObject#get:next
+         (get_global $~lib/collector/itcm/iter)
+        )
+        (get_global $~lib/collector/itcm/to)
+       )
+       (block
+        (set_local $0
+         (get_global $~lib/collector/itcm/from)
+        )
+        (set_global $~lib/collector/itcm/from
+         (get_global $~lib/collector/itcm/to)
+        )
+        (set_global $~lib/collector/itcm/to
+         (get_local $0)
+        )
+        (set_global $~lib/collector/itcm/white
+         (i32.eqz
+          (get_global $~lib/collector/itcm/white)
+         )
+        )
+        (set_global $~lib/collector/itcm/iter
+         (call $~lib/collector/itcm/ManagedObject#get:next
+          (get_local $0)
+         )
+        )
+        (set_global $~lib/collector/itcm/state
+         (i32.const 3)
+        )
+        (call $~lib/env/trace
+         (i32.const 420)
+         (i32.const 0)
+         (f64.const 0)
+         (f64.const 0)
+         (f64.const 0)
+         (f64.const 0)
+         (f64.const 0)
+        )
+       )
+      )
+     )
+    )
+    (br $break|0)
+   )
+   (if
+    (i32.ne
+     (tee_local $0
+      (get_global $~lib/collector/itcm/iter)
+     )
+     (get_global $~lib/collector/itcm/to)
+    )
+    (block
+     (call $~lib/env/trace
+      (i32.const 456)
+      (i32.const 1)
+      (f64.convert_u/i32
+       (i32.add
+        (get_local $0)
+        (i32.const 16)
+       )
+      )
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+     )
+     (set_global $~lib/collector/itcm/iter
+      (call $~lib/collector/itcm/ManagedObject#get:next
+       (get_local $0)
+      )
+     )
+     (call $~lib/memory/memory.free
+      (get_local $0)
+     )
+    )
+    (block
+     (call $~lib/env/trace
+      (i32.const 496)
+      (i32.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+     )
+     (call $~lib/collector/itcm/ManagedObject#clear
+      (get_global $~lib/collector/itcm/to)
+     )
+     (set_global $~lib/collector/itcm/state
+      (i32.const 1)
+     )
+     (call $~lib/env/trace
+      (i32.const 84)
+      (i32.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+      (f64.const 0)
+     )
+    )
+   )
+  )
+ )
+ (func $~lib/collector/itcm/__gc_allocate (; 18 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
   (local $2 i32)
+  (call $~lib/env/trace
+   (i32.const 8)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (get_local $0)
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
   (if
    (i32.gt_u
     (get_local $0)
     (i32.const 1073741808)
    )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 8)
-     (i32.const 216)
-     (i32.const 2)
-    )
-    (unreachable)
-   )
+   (unreachable)
   )
-  (call $~lib/collector/itcm/ManagedObject#makeWhite
+  (call $~lib/collector/itcm/step)
+  (i32.store offset=8
    (tee_local $2
     (call $~lib/memory/memory.allocate
      (i32.add
@@ -193,13 +701,14 @@
      )
     )
    )
-  )
-  (i32.store offset=8
-   (get_local $2)
    (get_local $1)
   )
-  (call $~lib/collector/itcm/ManagedObject#insert
-   (get_global $~lib/collector/itcm/set1)
+  (call $~lib/collector/itcm/ManagedObject#set:color
+   (get_local $2)
+   (get_global $~lib/collector/itcm/white)
+  )
+  (call $~lib/collector/itcm/ManagedObject#push
+   (get_global $~lib/collector/itcm/from)
    (get_local $2)
   )
   (i32.add
@@ -207,15 +716,78 @@
    (i32.const 16)
   )
  )
- (func $~lib/gc/gc.allocate (; 8 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
+ (func $~lib/gc/gc.allocate (; 19 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
   (call $~lib/collector/itcm/__gc_allocate
    (get_local $0)
    (get_local $1)
   )
  )
- (func $start (; 9 ;) (type $v)
+ (func $~lib/collector/itcm/__gc_collect (; 20 ;) (type $v)
+  (local $0 i32)
+  (call $~lib/env/trace
+   (i32.const 564)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (block $break|0
+   (block $case1|0
+    (br_if $case1|0
+     (i32.eqz
+      (tee_local $0
+       (get_global $~lib/collector/itcm/state)
+      )
+     )
+    )
+    (br_if $case1|0
+     (i32.eq
+      (get_local $0)
+      (i32.const 1)
+     )
+    )
+    (br $break|0)
+   )
+   (call $~lib/collector/itcm/step)
+  )
+  (loop $continue|1
+   (if
+    (i32.ne
+     (get_global $~lib/collector/itcm/state)
+     (i32.const 1)
+    )
+    (block
+     (call $~lib/collector/itcm/step)
+     (br $continue|1)
+    )
+   )
+  )
+ )
+ (func $~lib/gc/gc.collect (; 21 ;) (type $v)
+  (call $~lib/collector/itcm/__gc_collect)
+ )
+ (func $std/gc/main (; 22 ;) (type $i) (result i32)
+  (if
+   (i32.eqz
+    (get_global $~started)
+   )
+   (block
+    (call $start)
+    (set_global $~started
+     (i32.const 1)
+    )
+   )
+  )
+  (i32.const 0)
+ )
+ (func $start (; 23 ;) (type $v)
+  (local $0 i32)
+  (local $1 i32)
+  (local $2 i32)
   (set_global $~lib/allocator/arena/startOffset
-   (i32.const 80)
+   (i32.const 592)
   )
   (set_global $~lib/allocator/arena/offset
    (get_global $~lib/allocator/arena/startOffset)
@@ -239,30 +811,51 @@
     (i32.const 16)
    )
   )
-  (if
-   (i32.load
-    (get_global $std/gc/head)
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 56)
-     (i32.const 16)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
-  (if
+  (set_local $1
    (i32.load offset=4
     (get_global $std/gc/head)
    )
+  )
+  (if
+   (tee_local $0
+    (i32.ne
+     (tee_local $2
+      (i32.and
+       (i32.load
+        (get_global $std/gc/head)
+       )
+       (i32.const -4)
+      )
+     )
+     (i32.const 0)
+    )
+   )
+   (set_local $0
+    (i32.ne
+     (get_local $1)
+     (i32.const 0)
+    )
+   )
+  )
+  (if
+   (get_local $0)
+   (set_local $0
+    (i32.eq
+     (get_local $2)
+     (get_local $1)
+    )
+   )
+  )
+  (if
+   (i32.eqz
+    (get_local $0)
+   )
    (block
     (call $~lib/env/abort
      (i32.const 0)
-     (i32.const 56)
-     (i32.const 17)
-     (i32.const 0)
+     (i32.const 540)
+     (i32.const 19)
+     (i32.const 2)
     )
     (unreachable)
    )
@@ -274,9 +867,9 @@
    (block
     (call $~lib/env/abort
      (i32.const 0)
-     (i32.const 56)
-     (i32.const 18)
-     (i32.const 0)
+     (i32.const 540)
+     (i32.const 21)
+     (i32.const 2)
     )
     (unreachable)
    )
@@ -288,9 +881,9 @@
    (block
     (call $~lib/env/abort
      (i32.const 0)
-     (i32.const 56)
-     (i32.const 19)
-     (i32.const 0)
+     (i32.const 540)
+     (i32.const 23)
+     (i32.const 2)
     )
     (unreachable)
    )
@@ -305,12 +898,17 @@
    (block
     (call $~lib/env/abort
      (i32.const 0)
-     (i32.const 56)
-     (i32.const 21)
-     (i32.const 0)
+     (i32.const 540)
+     (i32.const 25)
+     (i32.const 2)
     )
     (unreachable)
    )
   )
+  (call $~lib/gc/gc.collect)
+  (set_global $std/gc/obj
+   (i32.const 0)
+  )
+  (call $~lib/gc/gc.collect)
  )
 )
diff --git a/tests/compiler/std/gc.ts b/tests/compiler/std/gc.ts
index 9c7ae1ed..47534e85 100644
--- a/tests/compiler/std/gc.ts
+++ b/tests/compiler/std/gc.ts
@@ -5,19 +5,31 @@ import "collector/itcm";
 class MyObject {
   a: u32;
 }
-function MyObject_visit(ref: usize): void { }
+function MyObject_visit(ref: usize): void {} // function table index == classId ?
 
 // allocate a managed instance
-var obj = changetype<MyObject>(gc.allocate(offsetof<MyObject>(), MyObject_visit));
+var obj: MyObject | null = changetype<MyObject>(gc.allocate(offsetof<MyObject>(), MyObject_visit));
 obj.a = 123;
 var head = changetype<usize>(obj) - 16;
 
-// header
-assert(load<u32>(head, 0) == 0); // nextWithFlags
-assert(load<u32>(head, 4) == 0); // prev
-assert(load<u32>(head, 8) == changetype<u32>(MyObject_visit)); // visitFn
-assert(load<u32>(head, 12) == 0); // unused
-// contents
-assert(load<u32>(head, 16) == 123); // Obj#a
+// check header
+{
+  let next = load<u32>(head, 0) & ~3;
+  let prev = load<u32>(head, 4);
+  assert(next != 0 && prev != 0 && next == prev);
+  let visitFn = load<u32>(head, 8);
+  assert(visitFn == changetype<u32>(MyObject_visit));
+  let unused = load<u32>(head, 12);
+  assert(unused == 0);
+  let a = load<u32>(head, 16);
+  assert(a == 123);
+}
 
-// gc.collect(); // FIXME: endless loop
+gc.collect(); // should keep 'obj' because it's a referenced root (see trace output)
+obj = null;
+gc.collect(); // should free 'obj' because it isn't referenced anymore (see trace output)
+
+export function main(): i32 { return 0; }
+
+// BEWARE: The compiler does not emit any integrations except gc.iterateRoots yet, hence trying to
+// use the GC with a 'normally' allocated object will break it, as it has no managed header!
diff --git a/tests/compiler/std/gc.untouched.wat b/tests/compiler/std/gc.untouched.wat
index 15b686ea..4e8e0a53 100644
--- a/tests/compiler/std/gc.untouched.wat
+++ b/tests/compiler/std/gc.untouched.wat
@@ -1,10 +1,13 @@
 (module
  (type $iv (func (param i32)))
  (type $iii (func (param i32 i32) (result i32)))
- (type $iiiiv (func (param i32 i32 i32 i32)))
+ (type $iiFFFFFv (func (param i32 i32 f64 f64 f64 f64 f64)))
+ (type $v (func))
  (type $ii (func (param i32) (result i32)))
  (type $iiv (func (param i32 i32)))
- (type $v (func))
+ (type $iiiiv (func (param i32 i32 i32 i32)))
+ (type $i (func (result i32)))
+ (import "env" "trace" (func $~lib/env/trace (param i32 i32 f64 f64 f64 f64 f64)))
  (import "env" "abort" (func $~lib/env/abort (param i32 i32 i32 i32)))
  (global $~lib/internal/allocator/AL_BITS i32 (i32.const 3))
  (global $~lib/internal/allocator/AL_SIZE i32 (i32.const 8))
@@ -12,32 +15,51 @@
  (global $~lib/internal/allocator/MAX_SIZE_32 i32 (i32.const 1073741824))
  (global $~lib/allocator/arena/startOffset (mut i32) (i32.const 0))
  (global $~lib/allocator/arena/offset (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/TRACE i32 (i32.const 1))
  (global $~lib/collector/itcm/State.INIT i32 (i32.const 0))
  (global $~lib/collector/itcm/State.IDLE i32 (i32.const 1))
  (global $~lib/collector/itcm/State.MARK i32 (i32.const 2))
  (global $~lib/collector/itcm/State.SWEEP i32 (i32.const 3))
  (global $~lib/collector/itcm/state (mut i32) (i32.const 0))
- (global $~lib/collector/itcm/set1 (mut i32) (i32.const 0))
- (global $~lib/collector/itcm/set2 (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/white (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/from (mut i32) (i32.const 0))
+ (global $~lib/collector/itcm/to (mut i32) (i32.const 0))
  (global $~lib/collector/itcm/iter (mut i32) (i32.const 0))
  (global $~lib/collector/itcm/ManagedObject.SIZE i32 (i32.const 16))
- (global $~lib/collector/itcm/Flags.MASK i32 (i32.const 7))
- (global $~lib/collector/itcm/Flags.WHITE (mut i32) (i32.const 0))
+ (global $~argc (mut i32) (i32.const 0))
  (global $std/gc/obj (mut i32) (i32.const 0))
  (global $std/gc/head (mut i32) (i32.const 0))
- (global $HEAP_BASE i32 (i32.const 80))
- (table 1 1 anyfunc)
- (elem (i32.const 0) $std/gc/MyObject_visit)
+ (global $~started (mut i32) (i32.const 0))
+ (global $HEAP_BASE i32 (i32.const 588))
+ (table 2 2 anyfunc)
+ (elem (i32.const 0) $std/gc/MyObject_visit $~lib/collector/itcm/markRoots~markRoot|1)
  (memory $0 1)
- (data (i32.const 8) "\16\00\00\00~\00l\00i\00b\00/\00c\00o\00l\00l\00e\00c\00t\00o\00r\00/\00i\00t\00c\00m\00.\00t\00s\00")
- (data (i32.const 56) "\t\00\00\00s\00t\00d\00/\00g\00c\00.\00t\00s\00")
+ (data (i32.const 8) "\0b\00\00\00g\00c\00.\00a\00l\00l\00o\00c\00a\00t\00e\00")
+ (data (i32.const 36) "\0c\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00I\00N\00I\00T\00")
+ (data (i32.const 64) "\08\00\00\00 \00 \00 \00c\00l\00e\00a\00r\00")
+ (data (i32.const 84) "\0f\00\00\00g\00c\00~\00s\00t\00a\00t\00e\00 \00=\00 \00I\00D\00L\00E\00")
+ (data (i32.const 120) "\0c\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00I\00D\00L\00E\00")
+ (data (i32.const 148) "\0c\00\00\00 \00 \00 \00m\00a\00r\00k\00R\00o\00o\00t\00s\00")
+ (data (i32.const 176) "\0b\00\00\00 \00 \00 \00m\00a\00r\00k\00R\00o\00o\00t\00")
+ (data (i32.const 204) "\07\00\00\00g\00c\00.\00m\00a\00r\00k\00")
+ (data (i32.const 224) "\0b\00\00\00 \00 \00 \00m\00a\00k\00e\00G\00r\00a\00y\00")
+ (data (i32.const 252) "\t\00\00\00 \00 \00 \00u\00n\00l\00i\00n\00k\00")
+ (data (i32.const 276) "\07\00\00\00 \00 \00 \00p\00u\00s\00h\00")
+ (data (i32.const 296) "\0f\00\00\00g\00c\00~\00s\00t\00a\00t\00e\00 \00=\00 \00M\00A\00R\00K\00")
+ (data (i32.const 332) "\14\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00M\00A\00R\00K\00 \00i\00t\00e\00r\00a\00t\00e\00")
+ (data (i32.const 376) "\13\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00M\00A\00R\00K\00 \00f\00i\00n\00i\00s\00h\00")
+ (data (i32.const 420) "\10\00\00\00g\00c\00~\00s\00t\00a\00t\00e\00 \00=\00 \00S\00W\00E\00E\00P\00")
+ (data (i32.const 456) "\12\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00S\00W\00E\00E\00P\00 \00f\00r\00e\00e\00")
+ (data (i32.const 496) "\14\00\00\00g\00c\00~\00s\00t\00e\00p\00/\00S\00W\00E\00E\00P\00 \00f\00i\00n\00i\00s\00h\00")
+ (data (i32.const 540) "\t\00\00\00s\00t\00d\00/\00g\00c\00.\00t\00s\00")
+ (data (i32.const 564) "\n\00\00\00g\00c\00.\00c\00o\00l\00l\00e\00c\00t\00")
  (export "memory" (memory $0))
  (export "table" (table $0))
- (start $start)
- (func $std/gc/MyObject_visit (; 1 ;) (type $iv) (param $0 i32)
+ (export "main" (func $std/gc/main))
+ (func $std/gc/MyObject_visit (; 2 ;) (type $iv) (param $0 i32)
   (nop)
  )
- (func $~lib/allocator/arena/__memory_allocate (; 2 ;) (type $ii) (param $0 i32) (result i32)
+ (func $~lib/allocator/arena/__memory_allocate (; 3 ;) (type $ii) (param $0 i32) (result i32)
   (local $1 i32)
   (local $2 i32)
   (local $3 i32)
@@ -145,14 +167,213 @@
   )
   (i32.const 0)
  )
- (func $~lib/memory/memory.allocate (; 3 ;) (type $ii) (param $0 i32) (result i32)
+ (func $~lib/memory/memory.allocate (; 4 ;) (type $ii) (param $0 i32) (result i32)
   (return
    (call $~lib/allocator/arena/__memory_allocate
     (get_local $0)
    )
   )
  )
- (func $~lib/collector/itcm/ManagedObject#makeWhite (; 4 ;) (type $iv) (param $0 i32)
+ (func $~lib/collector/itcm/ManagedObject#clear (; 5 ;) (type $iv) (param $0 i32)
+  (call $~lib/env/trace
+   (i32.const 64)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.0 (result i32)
+     (i32.add
+      (get_local $0)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (i32.store
+   (get_local $0)
+   (get_local $0)
+  )
+  (i32.store offset=4
+   (get_local $0)
+   (get_local $0)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#get:color (; 6 ;) (type $ii) (param $0 i32) (result i32)
+  (i32.and
+   (i32.load
+    (get_local $0)
+   )
+   (i32.const 3)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#get:next (; 7 ;) (type $ii) (param $0 i32) (result i32)
+  (i32.and
+   (i32.load
+    (get_local $0)
+   )
+   (i32.xor
+    (i32.const 3)
+    (i32.const -1)
+   )
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#set:next (; 8 ;) (type $iiv) (param $0 i32) (param $1 i32)
+  (i32.store
+   (get_local $0)
+   (i32.or
+    (get_local $1)
+    (i32.and
+     (i32.load
+      (get_local $0)
+     )
+     (i32.const 3)
+    )
+   )
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#unlink (; 9 ;) (type $iv) (param $0 i32)
+  (local $1 i32)
+  (local $2 i32)
+  (set_local $1
+   (call $~lib/collector/itcm/ManagedObject#get:next
+    (get_local $0)
+   )
+  )
+  (set_local $2
+   (i32.load offset=4
+    (get_local $0)
+   )
+  )
+  (call $~lib/env/trace
+   (i32.const 252)
+   (i32.const 3)
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.2 (result i32)
+     (i32.add
+      (get_local $2)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.3 (result i32)
+     (i32.add
+      (get_local $0)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.4 (result i32)
+     (i32.add
+      (get_local $1)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (i32.store offset=4
+   (get_local $1)
+   (get_local $2)
+  )
+  (call $~lib/collector/itcm/ManagedObject#set:next
+   (get_local $2)
+   (get_local $1)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#push (; 10 ;) (type $iiv) (param $0 i32) (param $1 i32)
+  (local $2 i32)
+  (set_local $2
+   (i32.load offset=4
+    (get_local $0)
+   )
+  )
+  (call $~lib/env/trace
+   (i32.const 276)
+   (i32.const 3)
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.5 (result i32)
+     (i32.add
+      (get_local $2)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.6 (result i32)
+     (i32.add
+      (get_local $1)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.7 (result i32)
+     (i32.add
+      (get_local $0)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/collector/itcm/ManagedObject#set:next
+   (get_local $1)
+   (get_local $0)
+  )
+  (i32.store offset=4
+   (get_local $1)
+   (get_local $2)
+  )
+  (call $~lib/collector/itcm/ManagedObject#set:next
+   (get_local $2)
+   (get_local $1)
+  )
+  (i32.store offset=4
+   (get_local $0)
+   (get_local $1)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#makeGray (; 11 ;) (type $iv) (param $0 i32)
+  (call $~lib/env/trace
+   (i32.const 224)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (block $~lib/collector/itcm/objToRef|inlined.1 (result i32)
+     (i32.add
+      (get_local $0)
+      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     )
+    )
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (if
+   (i32.eq
+    (get_local $0)
+    (get_global $~lib/collector/itcm/iter)
+   )
+   (set_global $~lib/collector/itcm/iter
+    (i32.load offset=4
+     (get_local $0)
+    )
+   )
+  )
+  (call $~lib/collector/itcm/ManagedObject#unlink
+   (get_local $0)
+  )
+  (call $~lib/collector/itcm/ManagedObject#push
+   (get_global $~lib/collector/itcm/to)
+   (get_local $0)
+  )
   (i32.store
    (get_local $0)
    (i32.or
@@ -161,74 +382,423 @@
       (get_local $0)
      )
      (i32.xor
-      (get_global $~lib/collector/itcm/Flags.MASK)
+      (i32.const 3)
       (i32.const -1)
      )
     )
-    (get_global $~lib/collector/itcm/Flags.WHITE)
+    (i32.const 2)
    )
   )
  )
- (func $~lib/collector/itcm/ManagedObject#set:next (; 5 ;) (type $iiv) (param $0 i32) (param $1 i32)
+ (func $~lib/collector/itcm/__gc_mark (; 12 ;) (type $iv) (param $0 i32)
+  (local $1 i32)
+  (call $~lib/env/trace
+   (i32.const 204)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (get_local $0)
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (set_local $1
+   (block $~lib/collector/itcm/refToObj|inlined.0 (result i32)
+    (i32.sub
+     (get_local $0)
+     (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+    )
+   )
+  )
+  (if
+   (i32.eq
+    (call $~lib/collector/itcm/ManagedObject#get:color
+     (get_local $1)
+    )
+    (get_global $~lib/collector/itcm/white)
+   )
+   (call $~lib/collector/itcm/ManagedObject#makeGray
+    (get_local $1)
+   )
+  )
+ )
+ (func $~lib/collector/itcm/markRoots~markRoot|1 (; 13 ;) (type $iv) (param $0 i32)
+  (call $~lib/env/trace
+   (i32.const 176)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (get_local $0)
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (if
+   (get_local $0)
+   (call $~lib/collector/itcm/__gc_mark
+    (get_local $0)
+   )
+  )
+ )
+ (func $~lib/collector/itcm/markRoots (; 14 ;) (type $v)
+  (call $~lib/env/trace
+   (i32.const 148)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call_indirect (type $iv)
+   (get_global $std/gc/obj)
+   (i32.const 1)
+  )
+ )
+ (func $~lib/collector/itcm/ManagedObject#set:color (; 15 ;) (type $iiv) (param $0 i32) (param $1 i32)
   (i32.store
    (get_local $0)
    (i32.or
-    (get_local $1)
     (i32.and
      (i32.load
       (get_local $0)
      )
-     (get_global $~lib/collector/itcm/Flags.MASK)
-    )
-   )
-  )
- )
- (func $~lib/collector/itcm/ManagedObject#insert (; 6 ;) (type $iiv) (param $0 i32) (param $1 i32)
-  (local $2 i32)
-  (set_local $2
-   (i32.load offset=4
-    (get_local $0)
-   )
-  )
-  (call $~lib/collector/itcm/ManagedObject#set:next
-   (get_local $1)
-   (get_local $0)
-  )
-  (i32.store offset=4
-   (get_local $1)
-   (get_local $2)
-  )
-  (call $~lib/collector/itcm/ManagedObject#set:next
-   (get_local $2)
-   (get_local $1)
-  )
-  (i32.store offset=4
-   (get_local $0)
-   (get_local $1)
-  )
- )
- (func $~lib/collector/itcm/__gc_allocate (; 7 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
-  (local $2 i32)
-  (if
-   (i32.eqz
-    (i32.le_u
-     (get_local $0)
-     (i32.sub
-      (get_global $~lib/internal/allocator/MAX_SIZE_32)
-      (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+     (i32.xor
+      (i32.const 3)
+      (i32.const -1)
      )
     )
+    (get_local $1)
+   )
+  )
+ )
+ (func $~lib/allocator/arena/__memory_free (; 16 ;) (type $iv) (param $0 i32)
+  (nop)
+ )
+ (func $~lib/memory/memory.free (; 17 ;) (type $iv) (param $0 i32)
+  (call $~lib/allocator/arena/__memory_free
+   (get_local $0)
+  )
+  (return)
+ )
+ (func $~lib/collector/itcm/step (; 18 ;) (type $v)
+  (local $0 i32)
+  (local $1 i32)
+  (block $break|0
+   (block $case3|0
+    (block $case2|0
+     (block $case1|0
+      (block $case0|0
+       (set_local $1
+        (get_global $~lib/collector/itcm/state)
+       )
+       (br_if $case0|0
+        (i32.eq
+         (get_local $1)
+         (get_global $~lib/collector/itcm/State.INIT)
+        )
+       )
+       (br_if $case1|0
+        (i32.eq
+         (get_local $1)
+         (get_global $~lib/collector/itcm/State.IDLE)
+        )
+       )
+       (br_if $case2|0
+        (i32.eq
+         (get_local $1)
+         (get_global $~lib/collector/itcm/State.MARK)
+        )
+       )
+       (br_if $case3|0
+        (i32.eq
+         (get_local $1)
+         (get_global $~lib/collector/itcm/State.SWEEP)
+        )
+       )
+       (br $break|0)
+      )
+      (block
+       (call $~lib/env/trace
+        (i32.const 36)
+        (i32.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+       )
+       (set_global $~lib/collector/itcm/from
+        (call $~lib/memory/memory.allocate
+         (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+        )
+       )
+       (i32.store offset=8
+        (get_global $~lib/collector/itcm/from)
+        (i32.const -1)
+       )
+       (call $~lib/collector/itcm/ManagedObject#clear
+        (get_global $~lib/collector/itcm/from)
+       )
+       (set_global $~lib/collector/itcm/to
+        (call $~lib/memory/memory.allocate
+         (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+        )
+       )
+       (i32.store offset=8
+        (get_global $~lib/collector/itcm/to)
+        (i32.const -1)
+       )
+       (call $~lib/collector/itcm/ManagedObject#clear
+        (get_global $~lib/collector/itcm/to)
+       )
+       (set_global $~lib/collector/itcm/iter
+        (get_global $~lib/collector/itcm/to)
+       )
+       (set_global $~lib/collector/itcm/state
+        (get_global $~lib/collector/itcm/State.IDLE)
+       )
+       (call $~lib/env/trace
+        (i32.const 84)
+        (i32.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+       )
+      )
+     )
+     (block
+      (call $~lib/env/trace
+       (i32.const 120)
+       (i32.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+      (call $~lib/collector/itcm/markRoots)
+      (set_global $~lib/collector/itcm/state
+       (get_global $~lib/collector/itcm/State.MARK)
+      )
+      (call $~lib/env/trace
+       (i32.const 296)
+       (i32.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+      (br $break|0)
+     )
+    )
+    (block
+     (set_local $0
+      (call $~lib/collector/itcm/ManagedObject#get:next
+       (get_global $~lib/collector/itcm/iter)
+      )
+     )
+     (if
+      (i32.ne
+       (get_local $0)
+       (get_global $~lib/collector/itcm/to)
+      )
+      (block
+       (call $~lib/env/trace
+        (i32.const 332)
+        (i32.const 1)
+        (f64.convert_u/i32
+         (block $~lib/collector/itcm/objToRef|inlined.8 (result i32)
+          (i32.add
+           (get_local $0)
+           (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+          )
+         )
+        )
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+       )
+       (set_global $~lib/collector/itcm/iter
+        (get_local $0)
+       )
+       (call $~lib/collector/itcm/ManagedObject#set:color
+        (get_local $0)
+        (i32.eqz
+         (get_global $~lib/collector/itcm/white)
+        )
+       )
+       (set_global $~argc
+        (i32.const 1)
+       )
+       (call_indirect (type $iv)
+        (block $~lib/collector/itcm/objToRef|inlined.9 (result i32)
+         (i32.add
+          (get_local $0)
+          (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+         )
+        )
+        (i32.load offset=8
+         (get_local $0)
+        )
+       )
+      )
+      (block
+       (call $~lib/env/trace
+        (i32.const 376)
+        (i32.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+        (f64.const 0)
+       )
+       (call $~lib/collector/itcm/markRoots)
+       (set_local $0
+        (call $~lib/collector/itcm/ManagedObject#get:next
+         (get_global $~lib/collector/itcm/iter)
+        )
+       )
+       (if
+        (i32.eq
+         (get_local $0)
+         (get_global $~lib/collector/itcm/to)
+        )
+        (block
+         (set_local $1
+          (get_global $~lib/collector/itcm/from)
+         )
+         (set_global $~lib/collector/itcm/from
+          (get_global $~lib/collector/itcm/to)
+         )
+         (set_global $~lib/collector/itcm/to
+          (get_local $1)
+         )
+         (set_global $~lib/collector/itcm/white
+          (i32.eqz
+           (get_global $~lib/collector/itcm/white)
+          )
+         )
+         (set_global $~lib/collector/itcm/iter
+          (call $~lib/collector/itcm/ManagedObject#get:next
+           (get_local $1)
+          )
+         )
+         (set_global $~lib/collector/itcm/state
+          (get_global $~lib/collector/itcm/State.SWEEP)
+         )
+         (call $~lib/env/trace
+          (i32.const 420)
+          (i32.const 0)
+          (f64.const 0)
+          (f64.const 0)
+          (f64.const 0)
+          (f64.const 0)
+          (f64.const 0)
+         )
+        )
+       )
+      )
+     )
+     (br $break|0)
+    )
    )
    (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 8)
-     (i32.const 216)
-     (i32.const 2)
+    (set_local $0
+     (get_global $~lib/collector/itcm/iter)
     )
-    (unreachable)
+    (if
+     (i32.ne
+      (get_local $0)
+      (get_global $~lib/collector/itcm/to)
+     )
+     (block
+      (call $~lib/env/trace
+       (i32.const 456)
+       (i32.const 1)
+       (f64.convert_u/i32
+        (block $~lib/collector/itcm/objToRef|inlined.10 (result i32)
+         (i32.add
+          (get_local $0)
+          (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+         )
+        )
+       )
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+      (set_global $~lib/collector/itcm/iter
+       (call $~lib/collector/itcm/ManagedObject#get:next
+        (get_local $0)
+       )
+      )
+      (call $~lib/memory/memory.free
+       (get_local $0)
+      )
+     )
+     (block
+      (call $~lib/env/trace
+       (i32.const 496)
+       (i32.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+      (call $~lib/collector/itcm/ManagedObject#clear
+       (get_global $~lib/collector/itcm/to)
+      )
+      (set_global $~lib/collector/itcm/state
+       (get_global $~lib/collector/itcm/State.IDLE)
+      )
+      (call $~lib/env/trace
+       (i32.const 84)
+       (i32.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+       (f64.const 0)
+      )
+     )
+    )
+    (br $break|0)
    )
   )
+ )
+ (func $~lib/collector/itcm/__gc_allocate (; 19 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
+  (local $2 i32)
+  (call $~lib/env/trace
+   (i32.const 8)
+   (i32.const 1)
+   (f64.convert_u/i32
+    (get_local $0)
+   )
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (if
+   (i32.gt_u
+    (get_local $0)
+    (i32.sub
+     (get_global $~lib/internal/allocator/MAX_SIZE_32)
+     (get_global $~lib/collector/itcm/ManagedObject.SIZE)
+    )
+   )
+   (unreachable)
+  )
+  (call $~lib/collector/itcm/step)
   (set_local $2
    (call $~lib/memory/memory.allocate
     (i32.add
@@ -237,25 +807,26 @@
     )
    )
   )
-  (call $~lib/collector/itcm/ManagedObject#makeWhite
-   (get_local $2)
-  )
   (i32.store offset=8
    (get_local $2)
    (get_local $1)
   )
-  (call $~lib/collector/itcm/ManagedObject#insert
-   (get_global $~lib/collector/itcm/set1)
+  (call $~lib/collector/itcm/ManagedObject#set:color
+   (get_local $2)
+   (get_global $~lib/collector/itcm/white)
+  )
+  (call $~lib/collector/itcm/ManagedObject#push
+   (get_global $~lib/collector/itcm/from)
    (get_local $2)
   )
-  (block $~lib/collector/itcm/objToRef|inlined.0 (result i32)
+  (block $~lib/collector/itcm/objToRef|inlined.11 (result i32)
    (i32.add
     (get_local $2)
     (get_global $~lib/collector/itcm/ManagedObject.SIZE)
    )
   )
  )
- (func $~lib/gc/gc.allocate (; 8 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
+ (func $~lib/gc/gc.allocate (; 20 ;) (type $iii) (param $0 i32) (param $1 i32) (result i32)
   (return
    (call $~lib/collector/itcm/__gc_allocate
     (get_local $0)
@@ -263,7 +834,79 @@
    )
   )
  )
- (func $start (; 9 ;) (type $v)
+ (func $~lib/collector/itcm/__gc_collect (; 21 ;) (type $v)
+  (local $0 i32)
+  (call $~lib/env/trace
+   (i32.const 564)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (block $break|0
+   (block $case1|0
+    (block $case0|0
+     (set_local $0
+      (get_global $~lib/collector/itcm/state)
+     )
+     (br_if $case0|0
+      (i32.eq
+       (get_local $0)
+       (get_global $~lib/collector/itcm/State.INIT)
+      )
+     )
+     (br_if $case1|0
+      (i32.eq
+       (get_local $0)
+       (get_global $~lib/collector/itcm/State.IDLE)
+      )
+     )
+     (br $break|0)
+    )
+   )
+   (call $~lib/collector/itcm/step)
+  )
+  (block $break|1
+   (loop $continue|1
+    (if
+     (i32.ne
+      (get_global $~lib/collector/itcm/state)
+      (get_global $~lib/collector/itcm/State.IDLE)
+     )
+     (block
+      (call $~lib/collector/itcm/step)
+      (br $continue|1)
+     )
+    )
+   )
+  )
+ )
+ (func $~lib/gc/gc.collect (; 22 ;) (type $v)
+  (call $~lib/collector/itcm/__gc_collect)
+  (return)
+ )
+ (func $std/gc/main (; 23 ;) (type $i) (result i32)
+  (if
+   (i32.eqz
+    (get_global $~started)
+   )
+   (block
+    (call $start)
+    (set_global $~started
+     (i32.const 1)
+    )
+   )
+  )
+  (i32.const 0)
+ )
+ (func $start (; 24 ;) (type $v)
+  (local $0 i32)
+  (local $1 i32)
+  (local $2 i32)
+  (local $3 i32)
+  (local $4 i32)
   (set_global $~lib/allocator/arena/startOffset
    (i32.and
     (i32.add
@@ -298,100 +941,129 @@
     (i32.const 16)
    )
   )
-  (if
-   (i32.eqz
-    (i32.eq
+  (block
+   (set_local $0
+    (i32.and
      (i32.load
       (get_global $std/gc/head)
      )
-     (i32.const 0)
-    )
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 56)
-     (i32.const 16)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
-  (if
-   (i32.eqz
-    (i32.eq
-     (i32.load offset=4
-      (get_global $std/gc/head)
+     (i32.xor
+      (i32.const 3)
+      (i32.const -1)
      )
-     (i32.const 0)
     )
    )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 56)
-     (i32.const 17)
-     (i32.const 0)
+   (set_local $1
+    (i32.load offset=4
+     (get_global $std/gc/head)
     )
-    (unreachable)
    )
-  )
-  (if
-   (i32.eqz
-    (i32.eq
-     (i32.load offset=8
-      (get_global $std/gc/head)
+   (if
+    (i32.eqz
+     (if (result i32)
+      (tee_local $2
+       (if (result i32)
+        (tee_local $2
+         (i32.ne
+          (get_local $0)
+          (i32.const 0)
+         )
+        )
+        (i32.ne
+         (get_local $1)
+         (i32.const 0)
+        )
+        (get_local $2)
+       )
+      )
+      (i32.eq
+       (get_local $0)
+       (get_local $1)
+      )
+      (get_local $2)
      )
-     (i32.const 0)
     )
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 56)
-     (i32.const 18)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
-  (if
-   (i32.eqz
-    (i32.eq
-     (i32.load offset=12
-      (get_global $std/gc/head)
+    (block
+     (call $~lib/env/abort
+      (i32.const 0)
+      (i32.const 540)
+      (i32.const 19)
+      (i32.const 2)
      )
-     (i32.const 0)
+     (unreachable)
     )
    )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 56)
-     (i32.const 19)
-     (i32.const 0)
+   (set_local $2
+    (i32.load offset=8
+     (get_global $std/gc/head)
     )
-    (unreachable)
    )
-  )
-  (if
-   (i32.eqz
-    (i32.eq
-     (i32.load offset=16
-      (get_global $std/gc/head)
+   (if
+    (i32.eqz
+     (i32.eq
+      (get_local $2)
+      (i32.const 0)
      )
-     (i32.const 123)
+    )
+    (block
+     (call $~lib/env/abort
+      (i32.const 0)
+      (i32.const 540)
+      (i32.const 21)
+      (i32.const 2)
+     )
+     (unreachable)
     )
    )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 56)
-     (i32.const 21)
-     (i32.const 0)
+   (set_local $3
+    (i32.load offset=12
+     (get_global $std/gc/head)
+    )
+   )
+   (if
+    (i32.eqz
+     (i32.eq
+      (get_local $3)
+      (i32.const 0)
+     )
+    )
+    (block
+     (call $~lib/env/abort
+      (i32.const 0)
+      (i32.const 540)
+      (i32.const 23)
+      (i32.const 2)
+     )
+     (unreachable)
+    )
+   )
+   (set_local $4
+    (i32.load offset=16
+     (get_global $std/gc/head)
+    )
+   )
+   (if
+    (i32.eqz
+     (i32.eq
+      (get_local $4)
+      (i32.const 123)
+     )
+    )
+    (block
+     (call $~lib/env/abort
+      (i32.const 0)
+      (i32.const 540)
+      (i32.const 25)
+      (i32.const 2)
+     )
+     (unreachable)
     )
-    (unreachable)
    )
   )
+  (call $~lib/gc/gc.collect)
+  (set_global $std/gc/obj
+   (i32.const 0)
+  )
+  (call $~lib/gc/gc.collect)
  )
 )
diff --git a/tests/compiler/std/string.optimized.wat b/tests/compiler/std/string.optimized.wat
index 0b47b006..28c47c49 100644
--- a/tests/compiler/std/string.optimized.wat
+++ b/tests/compiler/std/string.optimized.wat
@@ -4376,7 +4376,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 13)
+     (i32.const 11)
      (i32.const 0)
     )
     (unreachable)
@@ -4393,7 +4393,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 15)
+     (i32.const 13)
      (i32.const 0)
     )
     (unreachable)
@@ -4411,7 +4411,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 16)
+     (i32.const 14)
      (i32.const 0)
     )
     (unreachable)
@@ -4429,7 +4429,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 17)
+     (i32.const 15)
      (i32.const 0)
     )
     (unreachable)
@@ -4450,7 +4450,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 18)
+     (i32.const 16)
      (i32.const 0)
     )
     (unreachable)
@@ -4468,7 +4468,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 19)
+     (i32.const 17)
      (i32.const 0)
     )
     (unreachable)
@@ -4484,7 +4484,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 21)
+     (i32.const 19)
      (i32.const 0)
     )
     (unreachable)
@@ -4503,7 +4503,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 22)
+     (i32.const 20)
      (i32.const 0)
     )
     (unreachable)
@@ -4519,7 +4519,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 23)
+     (i32.const 21)
      (i32.const 0)
     )
     (unreachable)
@@ -4538,7 +4538,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 24)
+     (i32.const 22)
      (i32.const 0)
     )
     (unreachable)
@@ -4557,7 +4557,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 25)
+     (i32.const 23)
      (i32.const 0)
     )
     (unreachable)
@@ -4576,7 +4576,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 26)
+     (i32.const 24)
      (i32.const 0)
     )
     (unreachable)
@@ -4595,7 +4595,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 27)
+     (i32.const 25)
      (i32.const 0)
     )
     (unreachable)
@@ -4614,7 +4614,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 28)
+     (i32.const 26)
      (i32.const 0)
     )
     (unreachable)
@@ -4633,7 +4633,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 30)
+     (i32.const 28)
      (i32.const 0)
     )
     (unreachable)
@@ -4655,7 +4655,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 31)
+     (i32.const 29)
      (i32.const 0)
     )
     (unreachable)
@@ -4679,7 +4679,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 32)
+     (i32.const 30)
      (i32.const 0)
     )
     (unreachable)
@@ -4701,7 +4701,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 33)
+     (i32.const 31)
      (i32.const 0)
     )
     (unreachable)
@@ -4723,7 +4723,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 34)
+     (i32.const 32)
      (i32.const 0)
     )
     (unreachable)
@@ -4745,7 +4745,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 35)
+     (i32.const 33)
      (i32.const 0)
     )
     (unreachable)
@@ -4764,7 +4764,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 36)
+     (i32.const 34)
      (i32.const 0)
     )
     (unreachable)
@@ -4783,7 +4783,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 37)
+     (i32.const 35)
      (i32.const 0)
     )
     (unreachable)
@@ -4802,7 +4802,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 38)
+     (i32.const 36)
      (i32.const 0)
     )
     (unreachable)
@@ -4821,7 +4821,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 39)
+     (i32.const 37)
      (i32.const 0)
     )
     (unreachable)
@@ -4837,7 +4837,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 40)
+     (i32.const 38)
      (i32.const 0)
     )
     (unreachable)
@@ -4855,7 +4855,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 46)
+     (i32.const 44)
      (i32.const 0)
     )
     (unreachable)
@@ -4873,7 +4873,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 47)
+     (i32.const 45)
      (i32.const 0)
     )
     (unreachable)
@@ -4891,7 +4891,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 48)
+     (i32.const 46)
      (i32.const 0)
     )
     (unreachable)
@@ -4909,7 +4909,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 49)
+     (i32.const 47)
      (i32.const 0)
     )
     (unreachable)
@@ -4927,7 +4927,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 50)
+     (i32.const 48)
      (i32.const 0)
     )
     (unreachable)
@@ -4945,7 +4945,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 51)
+     (i32.const 49)
      (i32.const 0)
     )
     (unreachable)
@@ -4963,7 +4963,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 52)
+     (i32.const 50)
      (i32.const 0)
     )
     (unreachable)
@@ -4981,7 +4981,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 53)
+     (i32.const 51)
      (i32.const 0)
     )
     (unreachable)
@@ -4998,7 +4998,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 55)
+     (i32.const 53)
      (i32.const 0)
     )
     (unreachable)
@@ -5015,7 +5015,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 56)
+     (i32.const 54)
      (i32.const 0)
     )
     (unreachable)
@@ -5032,7 +5032,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 57)
+     (i32.const 55)
      (i32.const 0)
     )
     (unreachable)
@@ -5049,7 +5049,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 58)
+     (i32.const 56)
      (i32.const 0)
     )
     (unreachable)
@@ -5066,7 +5066,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 59)
+     (i32.const 57)
      (i32.const 0)
     )
     (unreachable)
@@ -5089,7 +5089,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 62)
+     (i32.const 60)
      (i32.const 0)
     )
     (unreachable)
@@ -5106,7 +5106,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 63)
+     (i32.const 61)
      (i32.const 0)
     )
     (unreachable)
@@ -5123,7 +5123,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 64)
+     (i32.const 62)
      (i32.const 0)
     )
     (unreachable)
@@ -5140,7 +5140,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 65)
+     (i32.const 63)
      (i32.const 0)
     )
     (unreachable)
@@ -5157,7 +5157,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 67)
+     (i32.const 65)
      (i32.const 0)
     )
     (unreachable)
@@ -5174,7 +5174,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 68)
+     (i32.const 66)
      (i32.const 0)
     )
     (unreachable)
@@ -5191,7 +5191,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 69)
+     (i32.const 67)
      (i32.const 0)
     )
     (unreachable)
@@ -5208,7 +5208,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 70)
+     (i32.const 68)
      (i32.const 0)
     )
     (unreachable)
@@ -5219,6 +5219,21 @@
     (i32.const 428)
     (i32.const 420)
    )
+   (block
+    (call $~lib/env/abort
+     (i32.const 0)
+     (i32.const 48)
+     (i32.const 69)
+     (i32.const 0)
+    )
+    (unreachable)
+   )
+  )
+  (if
+   (call $~lib/string/String.__lt
+    (i32.const 360)
+    (get_global $std/string/nullStr)
+   )
    (block
     (call $~lib/env/abort
      (i32.const 0)
@@ -5229,21 +5244,6 @@
     (unreachable)
    )
   )
-  (if
-   (call $~lib/string/String.__lt
-    (i32.const 360)
-    (get_global $std/string/nullStr)
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 48)
-     (i32.const 73)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
   (if
    (call $~lib/string/String.__lt
     (get_global $std/string/nullStr)
@@ -5253,7 +5253,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 74)
+     (i32.const 72)
      (i32.const 0)
     )
     (unreachable)
@@ -5270,7 +5270,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 76)
+     (i32.const 74)
      (i32.const 0)
     )
     (unreachable)
@@ -5287,7 +5287,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 77)
+     (i32.const 75)
      (i32.const 0)
     )
     (unreachable)
@@ -5304,7 +5304,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 78)
+     (i32.const 76)
      (i32.const 0)
     )
     (unreachable)
@@ -5321,7 +5321,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 79)
+     (i32.const 77)
      (i32.const 0)
     )
     (unreachable)
@@ -5332,6 +5332,36 @@
     (i32.const 444)
     (i32.const 8)
    )
+   (block
+    (call $~lib/env/abort
+     (i32.const 0)
+     (i32.const 48)
+     (i32.const 78)
+     (i32.const 0)
+    )
+    (unreachable)
+   )
+  )
+  (if
+   (call $~lib/string/String.__gt
+    (i32.const 8)
+    (i32.const 444)
+   )
+   (block
+    (call $~lib/env/abort
+     (i32.const 0)
+     (i32.const 48)
+     (i32.const 79)
+     (i32.const 0)
+    )
+    (unreachable)
+   )
+  )
+  (if
+   (call $~lib/string/String.__lt
+    (i32.const 8)
+    (i32.const 8)
+   )
    (block
     (call $~lib/env/abort
      (i32.const 0)
@@ -5345,7 +5375,7 @@
   (if
    (call $~lib/string/String.__gt
     (i32.const 8)
-    (i32.const 444)
+    (i32.const 8)
    )
    (block
     (call $~lib/env/abort
@@ -5357,36 +5387,6 @@
     (unreachable)
    )
   )
-  (if
-   (call $~lib/string/String.__lt
-    (i32.const 8)
-    (i32.const 8)
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 48)
-     (i32.const 82)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
-  (if
-   (call $~lib/string/String.__gt
-    (i32.const 8)
-    (i32.const 8)
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 48)
-     (i32.const 83)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
   (if
    (i32.eqz
     (call $~lib/string/String.__gte
@@ -5398,7 +5398,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 84)
+     (i32.const 82)
      (i32.const 0)
     )
     (unreachable)
@@ -5415,7 +5415,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 85)
+     (i32.const 83)
      (i32.const 0)
     )
     (unreachable)
@@ -5432,7 +5432,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 87)
+     (i32.const 85)
      (i32.const 0)
     )
     (unreachable)
@@ -5452,7 +5452,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 89)
+     (i32.const 87)
      (i32.const 0)
     )
     (unreachable)
@@ -5472,7 +5472,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 90)
+     (i32.const 88)
      (i32.const 0)
     )
     (unreachable)
@@ -5492,7 +5492,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 91)
+     (i32.const 89)
      (i32.const 0)
     )
     (unreachable)
@@ -5512,7 +5512,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 92)
+     (i32.const 90)
      (i32.const 0)
     )
     (unreachable)
@@ -5532,7 +5532,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 93)
+     (i32.const 91)
      (i32.const 0)
     )
     (unreachable)
@@ -5552,7 +5552,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 94)
+     (i32.const 92)
      (i32.const 0)
     )
     (unreachable)
@@ -5572,7 +5572,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 95)
+     (i32.const 93)
      (i32.const 0)
     )
     (unreachable)
@@ -5592,7 +5592,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 96)
+     (i32.const 94)
      (i32.const 0)
     )
     (unreachable)
@@ -5612,7 +5612,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 97)
+     (i32.const 95)
      (i32.const 0)
     )
     (unreachable)
@@ -5631,7 +5631,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 99)
+     (i32.const 97)
      (i32.const 0)
     )
     (unreachable)
@@ -5650,7 +5650,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 100)
+     (i32.const 98)
      (i32.const 0)
     )
     (unreachable)
@@ -5669,7 +5669,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 101)
+     (i32.const 99)
      (i32.const 0)
     )
     (unreachable)
@@ -5688,7 +5688,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 102)
+     (i32.const 100)
      (i32.const 0)
     )
     (unreachable)
@@ -5707,7 +5707,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 103)
+     (i32.const 101)
      (i32.const 0)
     )
     (unreachable)
@@ -5726,7 +5726,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 104)
+     (i32.const 102)
      (i32.const 0)
     )
     (unreachable)
@@ -5745,7 +5745,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 105)
+     (i32.const 103)
      (i32.const 0)
     )
     (unreachable)
@@ -5764,7 +5764,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 106)
+     (i32.const 104)
      (i32.const 0)
     )
     (unreachable)
@@ -5783,7 +5783,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 107)
+     (i32.const 105)
      (i32.const 0)
     )
     (unreachable)
@@ -5802,7 +5802,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 108)
+     (i32.const 106)
      (i32.const 0)
     )
     (unreachable)
@@ -5821,7 +5821,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 109)
+     (i32.const 107)
      (i32.const 0)
     )
     (unreachable)
@@ -5840,7 +5840,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 110)
+     (i32.const 108)
      (i32.const 0)
     )
     (unreachable)
@@ -5859,7 +5859,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 111)
+     (i32.const 109)
      (i32.const 0)
     )
     (unreachable)
@@ -5878,7 +5878,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 112)
+     (i32.const 110)
      (i32.const 0)
     )
     (unreachable)
@@ -5897,7 +5897,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 114)
+     (i32.const 112)
      (i32.const 0)
     )
     (unreachable)
@@ -5916,7 +5916,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 115)
+     (i32.const 113)
      (i32.const 0)
     )
     (unreachable)
@@ -5935,7 +5935,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 116)
+     (i32.const 114)
      (i32.const 0)
     )
     (unreachable)
@@ -5954,7 +5954,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 117)
+     (i32.const 115)
      (i32.const 0)
     )
     (unreachable)
@@ -5973,7 +5973,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 118)
+     (i32.const 116)
      (i32.const 0)
     )
     (unreachable)
@@ -5992,7 +5992,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 120)
+     (i32.const 118)
      (i32.const 0)
     )
     (unreachable)
@@ -6011,7 +6011,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 121)
+     (i32.const 119)
      (i32.const 0)
     )
     (unreachable)
@@ -6030,7 +6030,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 122)
+     (i32.const 120)
      (i32.const 0)
     )
     (unreachable)
@@ -6049,7 +6049,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 123)
+     (i32.const 121)
      (i32.const 0)
     )
     (unreachable)
@@ -6068,7 +6068,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 124)
+     (i32.const 122)
      (i32.const 0)
     )
     (unreachable)
@@ -6087,7 +6087,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 125)
+     (i32.const 123)
      (i32.const 0)
     )
     (unreachable)
@@ -6106,7 +6106,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 126)
+     (i32.const 124)
      (i32.const 0)
     )
     (unreachable)
@@ -6125,7 +6125,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 127)
+     (i32.const 125)
      (i32.const 0)
     )
     (unreachable)
@@ -6144,7 +6144,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 128)
+     (i32.const 126)
      (i32.const 0)
     )
     (unreachable)
@@ -6163,7 +6163,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 129)
+     (i32.const 127)
      (i32.const 0)
     )
     (unreachable)
@@ -6182,7 +6182,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 130)
+     (i32.const 128)
      (i32.const 0)
     )
     (unreachable)
@@ -6201,7 +6201,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 132)
+     (i32.const 130)
      (i32.const 0)
     )
     (unreachable)
@@ -6220,7 +6220,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 133)
+     (i32.const 131)
      (i32.const 0)
     )
     (unreachable)
@@ -6239,7 +6239,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 134)
+     (i32.const 132)
      (i32.const 0)
     )
     (unreachable)
@@ -6258,7 +6258,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 135)
+     (i32.const 133)
      (i32.const 0)
     )
     (unreachable)
@@ -6277,7 +6277,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 136)
+     (i32.const 134)
      (i32.const 0)
     )
     (unreachable)
@@ -6296,7 +6296,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 137)
+     (i32.const 135)
      (i32.const 0)
     )
     (unreachable)
@@ -6315,7 +6315,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 138)
+     (i32.const 136)
      (i32.const 0)
     )
     (unreachable)
@@ -6334,7 +6334,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 139)
+     (i32.const 137)
      (i32.const 0)
     )
     (unreachable)
@@ -6353,7 +6353,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 140)
+     (i32.const 138)
      (i32.const 0)
     )
     (unreachable)
@@ -6372,7 +6372,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 141)
+     (i32.const 139)
      (i32.const 0)
     )
     (unreachable)
@@ -6391,7 +6391,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 142)
+     (i32.const 140)
      (i32.const 0)
     )
     (unreachable)
diff --git a/tests/compiler/std/string.ts b/tests/compiler/std/string.ts
index 5215cdb4..2b3bba90 100644
--- a/tests/compiler/std/string.ts
+++ b/tests/compiler/std/string.ts
@@ -2,8 +2,6 @@ import "allocator/arena";
 
 import { utoa32, itoa32, utoa64, itoa64 } from "internal/itoa";
 
-// declare function logi(i: i32): void;
-
 // preliminary
 
 var str: string = "hi, I'm a string";
diff --git a/tests/compiler/std/string.untouched.wat b/tests/compiler/std/string.untouched.wat
index 6bb9a3c1..fc31eac9 100644
--- a/tests/compiler/std/string.untouched.wat
+++ b/tests/compiler/std/string.untouched.wat
@@ -5290,7 +5290,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 13)
+     (i32.const 11)
      (i32.const 0)
     )
     (unreachable)
@@ -5309,7 +5309,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 15)
+     (i32.const 13)
      (i32.const 0)
     )
     (unreachable)
@@ -5329,7 +5329,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 16)
+     (i32.const 14)
      (i32.const 0)
     )
     (unreachable)
@@ -5347,7 +5347,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 17)
+     (i32.const 15)
      (i32.const 0)
     )
     (unreachable)
@@ -5370,7 +5370,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 18)
+     (i32.const 16)
      (i32.const 0)
     )
     (unreachable)
@@ -5388,7 +5388,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 19)
+     (i32.const 17)
      (i32.const 0)
     )
     (unreachable)
@@ -5409,7 +5409,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 21)
+     (i32.const 19)
      (i32.const 0)
     )
     (unreachable)
@@ -5430,7 +5430,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 22)
+     (i32.const 20)
      (i32.const 0)
     )
     (unreachable)
@@ -5451,7 +5451,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 23)
+     (i32.const 21)
      (i32.const 0)
     )
     (unreachable)
@@ -5472,7 +5472,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 24)
+     (i32.const 22)
      (i32.const 0)
     )
     (unreachable)
@@ -5493,7 +5493,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 25)
+     (i32.const 23)
      (i32.const 0)
     )
     (unreachable)
@@ -5514,7 +5514,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 26)
+     (i32.const 24)
      (i32.const 0)
     )
     (unreachable)
@@ -5535,7 +5535,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 27)
+     (i32.const 25)
      (i32.const 0)
     )
     (unreachable)
@@ -5556,7 +5556,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 28)
+     (i32.const 26)
      (i32.const 0)
     )
     (unreachable)
@@ -5582,7 +5582,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 30)
+     (i32.const 28)
      (i32.const 0)
     )
     (unreachable)
@@ -5608,7 +5608,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 31)
+     (i32.const 29)
      (i32.const 0)
     )
     (unreachable)
@@ -5636,7 +5636,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 32)
+     (i32.const 30)
      (i32.const 0)
     )
     (unreachable)
@@ -5662,7 +5662,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 33)
+     (i32.const 31)
      (i32.const 0)
     )
     (unreachable)
@@ -5688,7 +5688,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 34)
+     (i32.const 32)
      (i32.const 0)
     )
     (unreachable)
@@ -5714,7 +5714,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 35)
+     (i32.const 33)
      (i32.const 0)
     )
     (unreachable)
@@ -5735,7 +5735,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 36)
+     (i32.const 34)
      (i32.const 0)
     )
     (unreachable)
@@ -5756,7 +5756,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 37)
+     (i32.const 35)
      (i32.const 0)
     )
     (unreachable)
@@ -5777,7 +5777,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 38)
+     (i32.const 36)
      (i32.const 0)
     )
     (unreachable)
@@ -5798,7 +5798,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 39)
+     (i32.const 37)
      (i32.const 0)
     )
     (unreachable)
@@ -5819,7 +5819,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 40)
+     (i32.const 38)
      (i32.const 0)
     )
     (unreachable)
@@ -5839,7 +5839,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 46)
+     (i32.const 44)
      (i32.const 0)
     )
     (unreachable)
@@ -5859,7 +5859,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 47)
+     (i32.const 45)
      (i32.const 0)
     )
     (unreachable)
@@ -5879,7 +5879,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 48)
+     (i32.const 46)
      (i32.const 0)
     )
     (unreachable)
@@ -5899,7 +5899,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 49)
+     (i32.const 47)
      (i32.const 0)
     )
     (unreachable)
@@ -5919,7 +5919,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 50)
+     (i32.const 48)
      (i32.const 0)
     )
     (unreachable)
@@ -5939,7 +5939,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 51)
+     (i32.const 49)
      (i32.const 0)
     )
     (unreachable)
@@ -5959,7 +5959,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 52)
+     (i32.const 50)
      (i32.const 0)
     )
     (unreachable)
@@ -5979,7 +5979,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 53)
+     (i32.const 51)
      (i32.const 0)
     )
     (unreachable)
@@ -5998,7 +5998,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 55)
+     (i32.const 53)
      (i32.const 0)
     )
     (unreachable)
@@ -6017,7 +6017,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 56)
+     (i32.const 54)
      (i32.const 0)
     )
     (unreachable)
@@ -6036,7 +6036,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 57)
+     (i32.const 55)
      (i32.const 0)
     )
     (unreachable)
@@ -6055,7 +6055,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 58)
+     (i32.const 56)
      (i32.const 0)
     )
     (unreachable)
@@ -6074,7 +6074,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 59)
+     (i32.const 57)
      (i32.const 0)
     )
     (unreachable)
@@ -6097,7 +6097,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 62)
+     (i32.const 60)
      (i32.const 0)
     )
     (unreachable)
@@ -6114,7 +6114,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 63)
+     (i32.const 61)
      (i32.const 0)
     )
     (unreachable)
@@ -6131,7 +6131,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 64)
+     (i32.const 62)
      (i32.const 0)
     )
     (unreachable)
@@ -6148,7 +6148,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 65)
+     (i32.const 63)
      (i32.const 0)
     )
     (unreachable)
@@ -6165,7 +6165,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 67)
+     (i32.const 65)
      (i32.const 0)
     )
     (unreachable)
@@ -6182,7 +6182,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 68)
+     (i32.const 66)
      (i32.const 0)
     )
     (unreachable)
@@ -6199,7 +6199,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 69)
+     (i32.const 67)
      (i32.const 0)
     )
     (unreachable)
@@ -6216,7 +6216,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 70)
+     (i32.const 68)
      (i32.const 0)
     )
     (unreachable)
@@ -6231,6 +6231,25 @@
      )
     )
    )
+   (block
+    (call $~lib/env/abort
+     (i32.const 0)
+     (i32.const 48)
+     (i32.const 69)
+     (i32.const 0)
+    )
+    (unreachable)
+   )
+  )
+  (if
+   (i32.eqz
+    (i32.eqz
+     (call $~lib/string/String.__lt
+      (i32.const 360)
+      (get_global $std/string/nullStr)
+     )
+    )
+   )
    (block
     (call $~lib/env/abort
      (i32.const 0)
@@ -6241,25 +6260,6 @@
     (unreachable)
    )
   )
-  (if
-   (i32.eqz
-    (i32.eqz
-     (call $~lib/string/String.__lt
-      (i32.const 360)
-      (get_global $std/string/nullStr)
-     )
-    )
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 48)
-     (i32.const 73)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
   (if
    (i32.eqz
     (i32.eqz
@@ -6273,7 +6273,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 74)
+     (i32.const 72)
      (i32.const 0)
     )
     (unreachable)
@@ -6290,7 +6290,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 76)
+     (i32.const 74)
      (i32.const 0)
     )
     (unreachable)
@@ -6307,7 +6307,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 77)
+     (i32.const 75)
      (i32.const 0)
     )
     (unreachable)
@@ -6324,7 +6324,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 78)
+     (i32.const 76)
      (i32.const 0)
     )
     (unreachable)
@@ -6341,7 +6341,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 79)
+     (i32.const 77)
      (i32.const 0)
     )
     (unreachable)
@@ -6356,6 +6356,44 @@
      )
     )
    )
+   (block
+    (call $~lib/env/abort
+     (i32.const 0)
+     (i32.const 48)
+     (i32.const 78)
+     (i32.const 0)
+    )
+    (unreachable)
+   )
+  )
+  (if
+   (i32.eqz
+    (i32.eqz
+     (call $~lib/string/String.__gt
+      (i32.const 8)
+      (i32.const 444)
+     )
+    )
+   )
+   (block
+    (call $~lib/env/abort
+     (i32.const 0)
+     (i32.const 48)
+     (i32.const 79)
+     (i32.const 0)
+    )
+    (unreachable)
+   )
+  )
+  (if
+   (i32.eqz
+    (i32.eqz
+     (call $~lib/string/String.__lt
+      (i32.const 8)
+      (i32.const 8)
+     )
+    )
+   )
    (block
     (call $~lib/env/abort
      (i32.const 0)
@@ -6371,7 +6409,7 @@
     (i32.eqz
      (call $~lib/string/String.__gt
       (i32.const 8)
-      (i32.const 444)
+      (i32.const 8)
      )
     )
    )
@@ -6385,44 +6423,6 @@
     (unreachable)
    )
   )
-  (if
-   (i32.eqz
-    (i32.eqz
-     (call $~lib/string/String.__lt
-      (i32.const 8)
-      (i32.const 8)
-     )
-    )
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 48)
-     (i32.const 82)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
-  (if
-   (i32.eqz
-    (i32.eqz
-     (call $~lib/string/String.__gt
-      (i32.const 8)
-      (i32.const 8)
-     )
-    )
-   )
-   (block
-    (call $~lib/env/abort
-     (i32.const 0)
-     (i32.const 48)
-     (i32.const 83)
-     (i32.const 0)
-    )
-    (unreachable)
-   )
-  )
   (if
    (i32.eqz
     (call $~lib/string/String.__gte
@@ -6434,7 +6434,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 84)
+     (i32.const 82)
      (i32.const 0)
     )
     (unreachable)
@@ -6451,7 +6451,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 85)
+     (i32.const 83)
      (i32.const 0)
     )
     (unreachable)
@@ -6470,7 +6470,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 87)
+     (i32.const 85)
      (i32.const 0)
     )
     (unreachable)
@@ -6490,7 +6490,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 89)
+     (i32.const 87)
      (i32.const 0)
     )
     (unreachable)
@@ -6510,7 +6510,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 90)
+     (i32.const 88)
      (i32.const 0)
     )
     (unreachable)
@@ -6530,7 +6530,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 91)
+     (i32.const 89)
      (i32.const 0)
     )
     (unreachable)
@@ -6550,7 +6550,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 92)
+     (i32.const 90)
      (i32.const 0)
     )
     (unreachable)
@@ -6570,7 +6570,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 93)
+     (i32.const 91)
      (i32.const 0)
     )
     (unreachable)
@@ -6590,7 +6590,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 94)
+     (i32.const 92)
      (i32.const 0)
     )
     (unreachable)
@@ -6610,7 +6610,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 95)
+     (i32.const 93)
      (i32.const 0)
     )
     (unreachable)
@@ -6630,7 +6630,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 96)
+     (i32.const 94)
      (i32.const 0)
     )
     (unreachable)
@@ -6650,7 +6650,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 97)
+     (i32.const 95)
      (i32.const 0)
     )
     (unreachable)
@@ -6669,7 +6669,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 99)
+     (i32.const 97)
      (i32.const 0)
     )
     (unreachable)
@@ -6688,7 +6688,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 100)
+     (i32.const 98)
      (i32.const 0)
     )
     (unreachable)
@@ -6707,7 +6707,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 101)
+     (i32.const 99)
      (i32.const 0)
     )
     (unreachable)
@@ -6726,7 +6726,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 102)
+     (i32.const 100)
      (i32.const 0)
     )
     (unreachable)
@@ -6745,7 +6745,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 103)
+     (i32.const 101)
      (i32.const 0)
     )
     (unreachable)
@@ -6764,7 +6764,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 104)
+     (i32.const 102)
      (i32.const 0)
     )
     (unreachable)
@@ -6783,7 +6783,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 105)
+     (i32.const 103)
      (i32.const 0)
     )
     (unreachable)
@@ -6802,7 +6802,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 106)
+     (i32.const 104)
      (i32.const 0)
     )
     (unreachable)
@@ -6821,7 +6821,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 107)
+     (i32.const 105)
      (i32.const 0)
     )
     (unreachable)
@@ -6840,7 +6840,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 108)
+     (i32.const 106)
      (i32.const 0)
     )
     (unreachable)
@@ -6859,7 +6859,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 109)
+     (i32.const 107)
      (i32.const 0)
     )
     (unreachable)
@@ -6878,7 +6878,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 110)
+     (i32.const 108)
      (i32.const 0)
     )
     (unreachable)
@@ -6897,7 +6897,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 111)
+     (i32.const 109)
      (i32.const 0)
     )
     (unreachable)
@@ -6916,7 +6916,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 112)
+     (i32.const 110)
      (i32.const 0)
     )
     (unreachable)
@@ -6935,7 +6935,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 114)
+     (i32.const 112)
      (i32.const 0)
     )
     (unreachable)
@@ -6954,7 +6954,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 115)
+     (i32.const 113)
      (i32.const 0)
     )
     (unreachable)
@@ -6973,7 +6973,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 116)
+     (i32.const 114)
      (i32.const 0)
     )
     (unreachable)
@@ -6992,7 +6992,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 117)
+     (i32.const 115)
      (i32.const 0)
     )
     (unreachable)
@@ -7011,7 +7011,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 118)
+     (i32.const 116)
      (i32.const 0)
     )
     (unreachable)
@@ -7030,7 +7030,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 120)
+     (i32.const 118)
      (i32.const 0)
     )
     (unreachable)
@@ -7049,7 +7049,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 121)
+     (i32.const 119)
      (i32.const 0)
     )
     (unreachable)
@@ -7068,7 +7068,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 122)
+     (i32.const 120)
      (i32.const 0)
     )
     (unreachable)
@@ -7087,7 +7087,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 123)
+     (i32.const 121)
      (i32.const 0)
     )
     (unreachable)
@@ -7106,7 +7106,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 124)
+     (i32.const 122)
      (i32.const 0)
     )
     (unreachable)
@@ -7125,7 +7125,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 125)
+     (i32.const 123)
      (i32.const 0)
     )
     (unreachable)
@@ -7144,7 +7144,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 126)
+     (i32.const 124)
      (i32.const 0)
     )
     (unreachable)
@@ -7163,7 +7163,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 127)
+     (i32.const 125)
      (i32.const 0)
     )
     (unreachable)
@@ -7182,7 +7182,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 128)
+     (i32.const 126)
      (i32.const 0)
     )
     (unreachable)
@@ -7201,7 +7201,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 129)
+     (i32.const 127)
      (i32.const 0)
     )
     (unreachable)
@@ -7220,7 +7220,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 130)
+     (i32.const 128)
      (i32.const 0)
     )
     (unreachable)
@@ -7239,7 +7239,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 132)
+     (i32.const 130)
      (i32.const 0)
     )
     (unreachable)
@@ -7258,7 +7258,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 133)
+     (i32.const 131)
      (i32.const 0)
     )
     (unreachable)
@@ -7277,7 +7277,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 134)
+     (i32.const 132)
      (i32.const 0)
     )
     (unreachable)
@@ -7296,7 +7296,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 135)
+     (i32.const 133)
      (i32.const 0)
     )
     (unreachable)
@@ -7315,7 +7315,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 136)
+     (i32.const 134)
      (i32.const 0)
     )
     (unreachable)
@@ -7334,7 +7334,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 137)
+     (i32.const 135)
      (i32.const 0)
     )
     (unreachable)
@@ -7353,7 +7353,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 138)
+     (i32.const 136)
      (i32.const 0)
     )
     (unreachable)
@@ -7372,7 +7372,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 139)
+     (i32.const 137)
      (i32.const 0)
     )
     (unreachable)
@@ -7391,7 +7391,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 140)
+     (i32.const 138)
      (i32.const 0)
     )
     (unreachable)
@@ -7410,7 +7410,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 141)
+     (i32.const 139)
      (i32.const 0)
     )
     (unreachable)
@@ -7429,7 +7429,7 @@
     (call $~lib/env/abort
      (i32.const 0)
      (i32.const 48)
-     (i32.const 142)
+     (i32.const 140)
      (i32.const 0)
     )
     (unreachable)
diff --git a/tests/compiler/std/trace.optimized.wat b/tests/compiler/std/trace.optimized.wat
new file mode 100644
index 00000000..3e56415a
--- /dev/null
+++ b/tests/compiler/std/trace.optimized.wat
@@ -0,0 +1,104 @@
+(module
+ (type $iiFFFFFv (func (param i32 i32 f64 f64 f64 f64 f64)))
+ (type $v (func))
+ (import "env" "trace" (func $~lib/env/trace (param i32 i32 f64 f64 f64 f64 f64)))
+ (global $~started (mut i32) (i32.const 0))
+ (memory $0 1)
+ (data (i32.const 8) "\0d\00\00\00z\00e\00r\00o\00_\00i\00m\00p\00l\00i\00c\00i\00t")
+ (data (i32.const 40) "\0d\00\00\00z\00e\00r\00o\00_\00e\00x\00p\00l\00i\00c\00i\00t")
+ (data (i32.const 72) "\07\00\00\00o\00n\00e\00_\00i\00n\00t")
+ (data (i32.const 92) "\07\00\00\00t\00w\00o\00_\00i\00n\00t")
+ (data (i32.const 112) "\t\00\00\00t\00h\00r\00e\00e\00_\00i\00n\00t")
+ (data (i32.const 136) "\08\00\00\00f\00o\00u\00r\00_\00i\00n\00t")
+ (data (i32.const 156) "\08\00\00\00f\00i\00v\00e\00_\00i\00n\00t")
+ (data (i32.const 176) "\08\00\00\00f\00i\00v\00e\00_\00d\00b\00l")
+ (export "memory" (memory $0))
+ (export "main" (func $std/trace/main))
+ (func $std/trace/main (; 1 ;) (type $v)
+  (if
+   (i32.eqz
+    (get_global $~started)
+   )
+   (block
+    (call $start)
+    (set_global $~started
+     (i32.const 1)
+    )
+   )
+  )
+ )
+ (func $start (; 2 ;) (type $v)
+  (call $~lib/env/trace
+   (i32.const 8)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 40)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 72)
+   (i32.const 1)
+   (f64.const 1)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 92)
+   (i32.const 2)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 112)
+   (i32.const 3)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 3)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 136)
+   (i32.const 4)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 3)
+   (f64.const 4)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 156)
+   (i32.const 5)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 3)
+   (f64.const 4)
+   (f64.const 5)
+  )
+  (call $~lib/env/trace
+   (i32.const 176)
+   (i32.const 5)
+   (f64.const 1.1)
+   (f64.const 2.2)
+   (f64.const 3.3)
+   (f64.const 4.4)
+   (f64.const 5.5)
+  )
+ )
+)
diff --git a/tests/compiler/std/trace.ts b/tests/compiler/std/trace.ts
new file mode 100644
index 00000000..0bd24612
--- /dev/null
+++ b/tests/compiler/std/trace.ts
@@ -0,0 +1,10 @@
+trace("zero_implicit");
+trace("zero_explicit", 0);
+trace("one_int", 1, 1);
+trace("two_int", 2, 1, 2);
+trace("three_int", 3, 1, 2, 3);
+trace("four_int", 4, 1, 2, 3, 4);
+trace("five_int", 5, 1, 2, 3, 4, 5);
+trace("five_dbl", 5, 1.1, 2.2, 3.3, 4.4, 5.5);
+
+export function main(): void {}
diff --git a/tests/compiler/std/trace.untouched.wat b/tests/compiler/std/trace.untouched.wat
new file mode 100644
index 00000000..4a24977d
--- /dev/null
+++ b/tests/compiler/std/trace.untouched.wat
@@ -0,0 +1,105 @@
+(module
+ (type $iiFFFFFv (func (param i32 i32 f64 f64 f64 f64 f64)))
+ (type $v (func))
+ (import "env" "trace" (func $~lib/env/trace (param i32 i32 f64 f64 f64 f64 f64)))
+ (global $~started (mut i32) (i32.const 0))
+ (global $HEAP_BASE i32 (i32.const 196))
+ (memory $0 1)
+ (data (i32.const 8) "\0d\00\00\00z\00e\00r\00o\00_\00i\00m\00p\00l\00i\00c\00i\00t\00")
+ (data (i32.const 40) "\0d\00\00\00z\00e\00r\00o\00_\00e\00x\00p\00l\00i\00c\00i\00t\00")
+ (data (i32.const 72) "\07\00\00\00o\00n\00e\00_\00i\00n\00t\00")
+ (data (i32.const 92) "\07\00\00\00t\00w\00o\00_\00i\00n\00t\00")
+ (data (i32.const 112) "\t\00\00\00t\00h\00r\00e\00e\00_\00i\00n\00t\00")
+ (data (i32.const 136) "\08\00\00\00f\00o\00u\00r\00_\00i\00n\00t\00")
+ (data (i32.const 156) "\08\00\00\00f\00i\00v\00e\00_\00i\00n\00t\00")
+ (data (i32.const 176) "\08\00\00\00f\00i\00v\00e\00_\00d\00b\00l\00")
+ (export "memory" (memory $0))
+ (export "main" (func $std/trace/main))
+ (func $std/trace/main (; 1 ;) (type $v)
+  (if
+   (i32.eqz
+    (get_global $~started)
+   )
+   (block
+    (call $start)
+    (set_global $~started
+     (i32.const 1)
+    )
+   )
+  )
+ )
+ (func $start (; 2 ;) (type $v)
+  (call $~lib/env/trace
+   (i32.const 8)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 40)
+   (i32.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 72)
+   (i32.const 1)
+   (f64.const 1)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 92)
+   (i32.const 2)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 0)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 112)
+   (i32.const 3)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 3)
+   (f64.const 0)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 136)
+   (i32.const 4)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 3)
+   (f64.const 4)
+   (f64.const 0)
+  )
+  (call $~lib/env/trace
+   (i32.const 156)
+   (i32.const 5)
+   (f64.const 1)
+   (f64.const 2)
+   (f64.const 3)
+   (f64.const 4)
+   (f64.const 5)
+  )
+  (call $~lib/env/trace
+   (i32.const 176)
+   (i32.const 5)
+   (f64.const 1.1)
+   (f64.const 2.2)
+   (f64.const 3.3)
+   (f64.const 4.4)
+   (f64.const 5.5)
+  )
+ )
+)