diff --git a/cl/_testrt/syncmap/in.go b/cl/_testrt/syncmap/in.go
new file mode 100644
index 000000000..d734860ab
--- /dev/null
+++ b/cl/_testrt/syncmap/in.go
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+func main() {
+	var m sync.Map
+	m.Store(1, "hello")
+	m.Store("1", 100)
+	v, ok := m.Load("1")
+	fmt.Println(v, ok)
+	m.Range(func(k, v interface{}) bool {
+		fmt.Printf("%#v %v\n", k, v)
+		return true
+	})
+}
diff --git a/cl/_testrt/syncmap/out.ll b/cl/_testrt/syncmap/out.ll
new file mode 100644
index 000000000..a7564eda4
--- /dev/null
+++ b/cl/_testrt/syncmap/out.ll
@@ -0,0 +1,225 @@
+; ModuleID = 'main'
+source_filename = "main"
+
+%"github.com/goplus/llgo/internal/runtime.eface" = type { ptr, ptr }
+%"github.com/goplus/llgo/internal/runtime.String" = type { ptr, i64 }
+%"github.com/goplus/llgo/internal/runtime.Slice" = type { ptr, i64, i64 }
+%"github.com/goplus/llgo/internal/runtime.iface" = type { ptr, ptr }
+
+@"main.init$guard" = global i1 false, align 1
+@__llgo_argc = global i32 0, align 4
+@__llgo_argv = global ptr null, align 8
+@_llgo_int = linkonce global ptr null, align 8
+@0 = private unnamed_addr constant [5 x i8] c"hello", align 1
+@_llgo_string = linkonce global ptr null, align 8
+@1 = private unnamed_addr constant [1 x i8] c"1", align 1
+@_llgo_bool = linkonce global ptr null, align 8
+@2 = private unnamed_addr constant [7 x i8] c"%#v %v\0A", align 1
+
+define void @main.init() {
+_llgo_0:
+  %0 = load i1, ptr @"main.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"main.init$guard", align 1
+  call void @fmt.init()
+  call void @sync.init()
+  call void @"main.init$after"()
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+define i32 @main(i32 %0, ptr %1) {
+_llgo_0:
+  store i32 %0, ptr @__llgo_argc, align 4
+  store ptr %1, ptr @__llgo_argv, align 8
+  call void @"github.com/goplus/llgo/internal/runtime.init"()
+  call void @main.init()
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
+  %3 = load ptr, ptr @_llgo_int, align 8
+  %4 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %4, i32 0, i32 0
+  store ptr %3, ptr %5, align 8
+  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %4, i32 0, i32 1
+  store ptr inttoptr (i64 1 to ptr), ptr %6, align 8
+  %7 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %4, align 8
+  %8 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %9 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %8, i32 0, i32 0
+  store ptr @0, ptr %9, align 8
+  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %8, i32 0, i32 1
+  store i64 5, ptr %10, align 4
+  %11 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %8, align 8
+  %12 = load ptr, ptr @_llgo_string, align 8
+  %13 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %11, ptr %13, align 8
+  %14 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %15 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %14, i32 0, i32 0
+  store ptr %12, ptr %15, align 8
+  %16 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %14, i32 0, i32 1
+  store ptr %13, ptr %16, align 8
+  %17 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %14, align 8
+  call void @"sync.(*Map).Store"(ptr %2, %"github.com/goplus/llgo/internal/runtime.eface" %7, %"github.com/goplus/llgo/internal/runtime.eface" %17)
+  %18 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %19 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %18, i32 0, i32 0
+  store ptr @1, ptr %19, align 8
+  %20 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %18, i32 0, i32 1
+  store i64 1, ptr %20, align 4
+  %21 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %18, align 8
+  %22 = load ptr, ptr @_llgo_string, align 8
+  %23 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %21, ptr %23, align 8
+  %24 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %25 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %24, i32 0, i32 0
+  store ptr %22, ptr %25, align 8
+  %26 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %24, i32 0, i32 1
+  store ptr %23, ptr %26, align 8
+  %27 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %24, align 8
+  %28 = load ptr, ptr @_llgo_int, align 8
+  %29 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %30 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %29, i32 0, i32 0
+  store ptr %28, ptr %30, align 8
+  %31 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %29, i32 0, i32 1
+  store ptr inttoptr (i64 100 to ptr), ptr %31, align 8
+  %32 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %29, align 8
+  call void @"sync.(*Map).Store"(ptr %2, %"github.com/goplus/llgo/internal/runtime.eface" %27, %"github.com/goplus/llgo/internal/runtime.eface" %32)
+  %33 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %34 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %33, i32 0, i32 0
+  store ptr @1, ptr %34, align 8
+  %35 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %33, i32 0, i32 1
+  store i64 1, ptr %35, align 4
+  %36 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %33, align 8
+  %37 = load ptr, ptr @_llgo_string, align 8
+  %38 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64 16)
+  store %"github.com/goplus/llgo/internal/runtime.String" %36, ptr %38, align 8
+  %39 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %40 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %39, i32 0, i32 0
+  store ptr %37, ptr %40, align 8
+  %41 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %39, i32 0, i32 1
+  store ptr %38, ptr %41, align 8
+  %42 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %39, align 8
+  %43 = call { %"github.com/goplus/llgo/internal/runtime.eface", i1 } @"sync.(*Map).Load"(ptr %2, %"github.com/goplus/llgo/internal/runtime.eface" %42)
+  %44 = extractvalue { %"github.com/goplus/llgo/internal/runtime.eface", i1 } %43, 0
+  %45 = extractvalue { %"github.com/goplus/llgo/internal/runtime.eface", i1 } %43, 1
+  %46 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
+  %47 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %46, i64 0
+  store %"github.com/goplus/llgo/internal/runtime.eface" %44, ptr %47, align 8
+  %48 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %46, i64 1
+  %49 = load ptr, ptr @_llgo_bool, align 8
+  %50 = sext i1 %45 to i64
+  %51 = inttoptr i64 %50 to ptr
+  %52 = alloca %"github.com/goplus/llgo/internal/runtime.eface", align 8
+  %53 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %52, i32 0, i32 0
+  store ptr %49, ptr %53, align 8
+  %54 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %52, i32 0, i32 1
+  store ptr %51, ptr %54, align 8
+  %55 = load %"github.com/goplus/llgo/internal/runtime.eface", ptr %52, align 8
+  store %"github.com/goplus/llgo/internal/runtime.eface" %55, ptr %48, align 8
+  %56 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %57 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %56, i32 0, i32 0
+  store ptr %46, ptr %57, align 8
+  %58 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %56, i32 0, i32 1
+  store i64 2, ptr %58, align 4
+  %59 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %56, i32 0, i32 2
+  store i64 2, ptr %59, align 4
+  %60 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %56, align 8
+  %61 = call { i64, %"github.com/goplus/llgo/internal/runtime.iface" } @fmt.Println(%"github.com/goplus/llgo/internal/runtime.Slice" %60)
+  %62 = alloca { ptr, ptr }, align 8
+  %63 = getelementptr inbounds { ptr, ptr }, ptr %62, i32 0, i32 0
+  store ptr @"__llgo_stub.main.main$1", ptr %63, align 8
+  %64 = getelementptr inbounds { ptr, ptr }, ptr %62, i32 0, i32 1
+  store ptr null, ptr %64, align 8
+  %65 = load { ptr, ptr }, ptr %62, align 8
+  call void @"sync.(*Map).Range"(ptr %2, { ptr, ptr } %65)
+  ret i32 0
+}
+
+define i1 @"main.main$1"(%"github.com/goplus/llgo/internal/runtime.eface" %0, %"github.com/goplus/llgo/internal/runtime.eface" %1) {
+_llgo_0:
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 32)
+  %3 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, i64 0
+  store %"github.com/goplus/llgo/internal/runtime.eface" %0, ptr %3, align 8
+  %4 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.eface", ptr %2, i64 1
+  store %"github.com/goplus/llgo/internal/runtime.eface" %1, ptr %4, align 8
+  %5 = alloca %"github.com/goplus/llgo/internal/runtime.Slice", align 8
+  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %5, i32 0, i32 0
+  store ptr %2, ptr %6, align 8
+  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %5, i32 0, i32 1
+  store i64 2, ptr %7, align 4
+  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Slice", ptr %5, i32 0, i32 2
+  store i64 2, ptr %8, align 4
+  %9 = load %"github.com/goplus/llgo/internal/runtime.Slice", ptr %5, align 8
+  %10 = alloca %"github.com/goplus/llgo/internal/runtime.String", align 8
+  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %10, i32 0, i32 0
+  store ptr @2, ptr %11, align 8
+  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.String", ptr %10, i32 0, i32 1
+  store i64 7, ptr %12, align 4
+  %13 = load %"github.com/goplus/llgo/internal/runtime.String", ptr %10, align 8
+  %14 = call { i64, %"github.com/goplus/llgo/internal/runtime.iface" } @fmt.Printf(%"github.com/goplus/llgo/internal/runtime.String" %13, %"github.com/goplus/llgo/internal/runtime.Slice" %9)
+  ret i1 true
+}
+
+declare void @fmt.init()
+
+declare void @sync.init()
+
+declare void @"github.com/goplus/llgo/internal/runtime.init"()
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
+
+declare void @"sync.(*Map).Store"(ptr, %"github.com/goplus/llgo/internal/runtime.eface", %"github.com/goplus/llgo/internal/runtime.eface")
+
+define void @"main.init$after"() {
+_llgo_0:
+  %0 = load ptr, ptr @_llgo_int, align 8
+  %1 = icmp eq ptr %0, null
+  br i1 %1, label %_llgo_1, label %_llgo_2
+
+_llgo_1:                                          ; preds = %_llgo_0
+  %2 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 34)
+  store ptr %2, ptr @_llgo_int, align 8
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  %3 = load ptr, ptr @_llgo_string, align 8
+  %4 = icmp eq ptr %3, null
+  br i1 %4, label %_llgo_3, label %_llgo_4
+
+_llgo_3:                                          ; preds = %_llgo_2
+  %5 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 24)
+  store ptr %5, ptr @_llgo_string, align 8
+  br label %_llgo_4
+
+_llgo_4:                                          ; preds = %_llgo_3, %_llgo_2
+  %6 = load ptr, ptr @_llgo_bool, align 8
+  %7 = icmp eq ptr %6, null
+  br i1 %7, label %_llgo_5, label %_llgo_6
+
+_llgo_5:                                          ; preds = %_llgo_4
+  %8 = call ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64 33)
+  store ptr %8, ptr @_llgo_bool, align 8
+  br label %_llgo_6
+
+_llgo_6:                                          ; preds = %_llgo_5, %_llgo_4
+  ret void
+}
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.Basic"(i64)
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocU"(i64)
+
+declare { %"github.com/goplus/llgo/internal/runtime.eface", i1 } @"sync.(*Map).Load"(ptr, %"github.com/goplus/llgo/internal/runtime.eface")
+
+declare { i64, %"github.com/goplus/llgo/internal/runtime.iface" } @fmt.Println(%"github.com/goplus/llgo/internal/runtime.Slice")
+
+declare void @"sync.(*Map).Range"(ptr, { ptr, ptr })
+
+define linkonce i1 @"__llgo_stub.main.main$1"(ptr %0, %"github.com/goplus/llgo/internal/runtime.eface" %1, %"github.com/goplus/llgo/internal/runtime.eface" %2) {
+_llgo_0:
+  %3 = tail call i1 @"main.main$1"(%"github.com/goplus/llgo/internal/runtime.eface" %1, %"github.com/goplus/llgo/internal/runtime.eface" %2)
+  ret i1 %3
+}
+
+declare { i64, %"github.com/goplus/llgo/internal/runtime.iface" } @fmt.Printf(%"github.com/goplus/llgo/internal/runtime.String", %"github.com/goplus/llgo/internal/runtime.Slice")
diff --git a/internal/lib/sync/map.go b/internal/lib/sync/map.go
new file mode 100644
index 000000000..e8ccf58b5
--- /dev/null
+++ b/internal/lib/sync/map.go
@@ -0,0 +1,515 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sync
+
+import (
+	"sync/atomic"
+)
+
+// Map is like a Go map[interface{}]interface{} but is safe for concurrent use
+// by multiple goroutines without additional locking or coordination.
+// Loads, stores, and deletes run in amortized constant time.
+//
+// The Map type is specialized. Most code should use a plain Go map instead,
+// with separate locking or coordination, for better type safety and to make it
+// easier to maintain other invariants along with the map content.
+//
+// The Map type is optimized for two common use cases: (1) when the entry for a given
+// key is only ever written once but read many times, as in caches that only grow,
+// or (2) when multiple goroutines read, write, and overwrite entries for disjoint
+// sets of keys. In these two cases, use of a Map may significantly reduce lock
+// contention compared to a Go map paired with a separate Mutex or RWMutex.
+//
+// The zero Map is empty and ready for use. A Map must not be copied after first use.
+//
+// In the terminology of the Go memory model, Map arranges that a write operation
+// “synchronizes before” any read operation that observes the effect of the write, where
+// read and write operations are defined as follows.
+// Load, LoadAndDelete, LoadOrStore, Swap, CompareAndSwap, and CompareAndDelete
+// are read operations; Delete, LoadAndDelete, Store, and Swap are write operations;
+// LoadOrStore is a write operation when it returns loaded set to false;
+// CompareAndSwap is a write operation when it returns swapped set to true;
+// and CompareAndDelete is a write operation when it returns deleted set to true.
+type Map struct {
+	mu Mutex
+
+	// read contains the portion of the map's contents that are safe for
+	// concurrent access (with or without mu held).
+	//
+	// The read field itself is always safe to load, but must only be stored with
+	// mu held.
+	//
+	// Entries stored in read may be updated concurrently without mu, but updating
+	// a previously-expunged entry requires that the entry be copied to the dirty
+	// map and unexpunged with mu held.
+	read atomic.Pointer[readOnly]
+
+	// dirty contains the portion of the map's contents that require mu to be
+	// held. To ensure that the dirty map can be promoted to the read map quickly,
+	// it also includes all of the non-expunged entries in the read map.
+	//
+	// Expunged entries are not stored in the dirty map. An expunged entry in the
+	// clean map must be unexpunged and added to the dirty map before a new value
+	// can be stored to it.
+	//
+	// If the dirty map is nil, the next write to the map will initialize it by
+	// making a shallow copy of the clean map, omitting stale entries.
+	dirty map[any]*entry
+
+	// misses counts the number of loads since the read map was last updated that
+	// needed to lock mu to determine whether the key was present.
+	//
+	// Once enough misses have occurred to cover the cost of copying the dirty
+	// map, the dirty map will be promoted to the read map (in the unamended
+	// state) and the next store to the map will make a new dirty copy.
+	misses int
+}
+
+// readOnly is an immutable struct stored atomically in the Map.read field.
+type readOnly struct {
+	m       map[any]*entry
+	amended bool // true if the dirty map contains some key not in m.
+}
+
+// expunged is an arbitrary pointer that marks entries which have been deleted
+// from the dirty map.
+var expunged = new(any)
+
+// An entry is a slot in the map corresponding to a particular key.
+type entry struct {
+	// p points to the interface{} value stored for the entry.
+	//
+	// If p == nil, the entry has been deleted, and either m.dirty == nil or
+	// m.dirty[key] is e.
+	//
+	// If p == expunged, the entry has been deleted, m.dirty != nil, and the entry
+	// is missing from m.dirty.
+	//
+	// Otherwise, the entry is valid and recorded in m.read.m[key] and, if m.dirty
+	// != nil, in m.dirty[key].
+	//
+	// An entry can be deleted by atomic replacement with nil: when m.dirty is
+	// next created, it will atomically replace nil with expunged and leave
+	// m.dirty[key] unset.
+	//
+	// An entry's associated value can be updated by atomic replacement, provided
+	// p != expunged. If p == expunged, an entry's associated value can be updated
+	// only after first setting m.dirty[key] = e so that lookups using the dirty
+	// map find the entry.
+	p atomic.Pointer[any]
+}
+
+func newEntry(i any) *entry {
+	e := &entry{}
+	e.p.Store(&i)
+	return e
+}
+
+func (m *Map) loadReadOnly() readOnly {
+	if p := m.read.Load(); p != nil {
+		return *p
+	}
+	return readOnly{}
+}
+
+// Load returns the value stored in the map for a key, or nil if no
+// value is present.
+// The ok result indicates whether value was found in the map.
+func (m *Map) Load(key any) (value any, ok bool) {
+	read := m.loadReadOnly()
+	e, ok := read.m[key]
+	if !ok && read.amended {
+		m.mu.Lock()
+		// Avoid reporting a spurious miss if m.dirty got promoted while we were
+		// blocked on m.mu. (If further loads of the same key will not miss, it's
+		// not worth copying the dirty map for this key.)
+		read = m.loadReadOnly()
+		e, ok = read.m[key]
+		if !ok && read.amended {
+			e, ok = m.dirty[key]
+			// Regardless of whether the entry was present, record a miss: this key
+			// will take the slow path until the dirty map is promoted to the read
+			// map.
+			m.missLocked()
+		}
+		m.mu.Unlock()
+	}
+	if !ok {
+		return nil, false
+	}
+	return e.load()
+}
+
+func (e *entry) load() (value any, ok bool) {
+	p := e.p.Load()
+	if p == nil || p == expunged {
+		return nil, false
+	}
+	return *p, true
+}
+
+// Store sets the value for a key.
+func (m *Map) Store(key, value any) {
+	_, _ = m.Swap(key, value)
+}
+
+// tryCompareAndSwap compare the entry with the given old value and swaps
+// it with a new value if the entry is equal to the old value, and the entry
+// has not been expunged.
+//
+// If the entry is expunged, tryCompareAndSwap returns false and leaves
+// the entry unchanged.
+func (e *entry) tryCompareAndSwap(old, new any) bool {
+	p := e.p.Load()
+	if p == nil || p == expunged || *p != old {
+		return false
+	}
+
+	// Copy the interface after the first load to make this method more amenable
+	// to escape analysis: if the comparison fails from the start, we shouldn't
+	// bother heap-allocating an interface value to store.
+	nc := new
+	for {
+		if e.p.CompareAndSwap(p, &nc) {
+			return true
+		}
+		p = e.p.Load()
+		if p == nil || p == expunged || *p != old {
+			return false
+		}
+	}
+}
+
+// unexpungeLocked ensures that the entry is not marked as expunged.
+//
+// If the entry was previously expunged, it must be added to the dirty map
+// before m.mu is unlocked.
+func (e *entry) unexpungeLocked() (wasExpunged bool) {
+	return e.p.CompareAndSwap(expunged, nil)
+}
+
+// swapLocked unconditionally swaps a value into the entry.
+//
+// The entry must be known not to be expunged.
+func (e *entry) swapLocked(i *any) *any {
+	return e.p.Swap(i)
+}
+
+// LoadOrStore returns the existing value for the key if present.
+// Otherwise, it stores and returns the given value.
+// The loaded result is true if the value was loaded, false if stored.
+func (m *Map) LoadOrStore(key, value any) (actual any, loaded bool) {
+	// Avoid locking if it's a clean hit.
+	read := m.loadReadOnly()
+	if e, ok := read.m[key]; ok {
+		actual, loaded, ok := e.tryLoadOrStore(value)
+		if ok {
+			return actual, loaded
+		}
+	}
+
+	m.mu.Lock()
+	read = m.loadReadOnly()
+	if e, ok := read.m[key]; ok {
+		if e.unexpungeLocked() {
+			m.dirty[key] = e
+		}
+		actual, loaded, _ = e.tryLoadOrStore(value)
+	} else if e, ok := m.dirty[key]; ok {
+		actual, loaded, _ = e.tryLoadOrStore(value)
+		m.missLocked()
+	} else {
+		if !read.amended {
+			// We're adding the first new key to the dirty map.
+			// Make sure it is allocated and mark the read-only map as incomplete.
+			m.dirtyLocked()
+			m.read.Store(&readOnly{m: read.m, amended: true})
+		}
+		m.dirty[key] = newEntry(value)
+		actual, loaded = value, false
+	}
+	m.mu.Unlock()
+
+	return actual, loaded
+}
+
+// tryLoadOrStore atomically loads or stores a value if the entry is not
+// expunged.
+//
+// If the entry is expunged, tryLoadOrStore leaves the entry unchanged and
+// returns with ok==false.
+func (e *entry) tryLoadOrStore(i any) (actual any, loaded, ok bool) {
+	p := e.p.Load()
+	if p == expunged {
+		return nil, false, false
+	}
+	if p != nil {
+		return *p, true, true
+	}
+
+	// Copy the interface after the first load to make this method more amenable
+	// to escape analysis: if we hit the "load" path or the entry is expunged, we
+	// shouldn't bother heap-allocating.
+	ic := i
+	for {
+		if e.p.CompareAndSwap(nil, &ic) {
+			return i, false, true
+		}
+		p = e.p.Load()
+		if p == expunged {
+			return nil, false, false
+		}
+		if p != nil {
+			return *p, true, true
+		}
+	}
+}
+
+// LoadAndDelete deletes the value for a key, returning the previous value if any.
+// The loaded result reports whether the key was present.
+func (m *Map) LoadAndDelete(key any) (value any, loaded bool) {
+	read := m.loadReadOnly()
+	e, ok := read.m[key]
+	if !ok && read.amended {
+		m.mu.Lock()
+		read = m.loadReadOnly()
+		e, ok = read.m[key]
+		if !ok && read.amended {
+			e, ok = m.dirty[key]
+			delete(m.dirty, key)
+			// Regardless of whether the entry was present, record a miss: this key
+			// will take the slow path until the dirty map is promoted to the read
+			// map.
+			m.missLocked()
+		}
+		m.mu.Unlock()
+	}
+	if ok {
+		return e.delete()
+	}
+	return nil, false
+}
+
+// Delete deletes the value for a key.
+func (m *Map) Delete(key any) {
+	m.LoadAndDelete(key)
+}
+
+func (e *entry) delete() (value any, ok bool) {
+	for {
+		p := e.p.Load()
+		if p == nil || p == expunged {
+			return nil, false
+		}
+		if e.p.CompareAndSwap(p, nil) {
+			return *p, true
+		}
+	}
+}
+
+// trySwap swaps a value if the entry has not been expunged.
+//
+// If the entry is expunged, trySwap returns false and leaves the entry
+// unchanged.
+func (e *entry) trySwap(i *any) (*any, bool) {
+	for {
+		p := e.p.Load()
+		if p == expunged {
+			return nil, false
+		}
+		if e.p.CompareAndSwap(p, i) {
+			return p, true
+		}
+	}
+}
+
+// Swap swaps the value for a key and returns the previous value if any.
+// The loaded result reports whether the key was present.
+func (m *Map) Swap(key, value any) (previous any, loaded bool) {
+	read := m.loadReadOnly()
+	if e, ok := read.m[key]; ok {
+		if v, ok := e.trySwap(&value); ok {
+			if v == nil {
+				return nil, false
+			}
+			return *v, true
+		}
+	}
+
+	m.mu.Lock()
+	read = m.loadReadOnly()
+	if e, ok := read.m[key]; ok {
+		if e.unexpungeLocked() {
+			// The entry was previously expunged, which implies that there is a
+			// non-nil dirty map and this entry is not in it.
+			m.dirty[key] = e
+		}
+		if v := e.swapLocked(&value); v != nil {
+			loaded = true
+			previous = *v
+		}
+	} else if e, ok := m.dirty[key]; ok {
+		if v := e.swapLocked(&value); v != nil {
+			loaded = true
+			previous = *v
+		}
+	} else {
+		if !read.amended {
+			// We're adding the first new key to the dirty map.
+			// Make sure it is allocated and mark the read-only map as incomplete.
+			m.dirtyLocked()
+			m.read.Store(&readOnly{m: read.m, amended: true})
+		}
+		m.dirty[key] = newEntry(value)
+	}
+	m.mu.Unlock()
+	return previous, loaded
+}
+
+// CompareAndSwap swaps the old and new values for key
+// if the value stored in the map is equal to old.
+// The old value must be of a comparable type.
+func (m *Map) CompareAndSwap(key, old, new any) bool {
+	read := m.loadReadOnly()
+	if e, ok := read.m[key]; ok {
+		return e.tryCompareAndSwap(old, new)
+	} else if !read.amended {
+		return false // No existing value for key.
+	}
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	read = m.loadReadOnly()
+	swapped := false
+	if e, ok := read.m[key]; ok {
+		swapped = e.tryCompareAndSwap(old, new)
+	} else if e, ok := m.dirty[key]; ok {
+		swapped = e.tryCompareAndSwap(old, new)
+		// We needed to lock mu in order to load the entry for key,
+		// and the operation didn't change the set of keys in the map
+		// (so it would be made more efficient by promoting the dirty
+		// map to read-only).
+		// Count it as a miss so that we will eventually switch to the
+		// more efficient steady state.
+		m.missLocked()
+	}
+	return swapped
+}
+
+// CompareAndDelete deletes the entry for key if its value is equal to old.
+// The old value must be of a comparable type.
+//
+// If there is no current value for key in the map, CompareAndDelete
+// returns false (even if the old value is the nil interface value).
+func (m *Map) CompareAndDelete(key, old any) (deleted bool) {
+	read := m.loadReadOnly()
+	e, ok := read.m[key]
+	if !ok && read.amended {
+		m.mu.Lock()
+		read = m.loadReadOnly()
+		e, ok = read.m[key]
+		if !ok && read.amended {
+			e, ok = m.dirty[key]
+			// Don't delete key from m.dirty: we still need to do the “compare” part
+			// of the operation. The entry will eventually be expunged when the
+			// dirty map is promoted to the read map.
+			//
+			// Regardless of whether the entry was present, record a miss: this key
+			// will take the slow path until the dirty map is promoted to the read
+			// map.
+			m.missLocked()
+		}
+		m.mu.Unlock()
+	}
+	for ok {
+		p := e.p.Load()
+		if p == nil || p == expunged || *p != old {
+			return false
+		}
+		if e.p.CompareAndSwap(p, nil) {
+			return true
+		}
+	}
+	return false
+}
+
+// Range calls f sequentially for each key and value present in the map.
+// If f returns false, range stops the iteration.
+//
+// Range does not necessarily correspond to any consistent snapshot of the Map's
+// contents: no key will be visited more than once, but if the value for any key
+// is stored or deleted concurrently (including by f), Range may reflect any
+// mapping for that key from any point during the Range call. Range does not
+// block other methods on the receiver; even f itself may call any method on m.
+//
+// Range may be O(N) with the number of elements in the map even if f returns
+// false after a constant number of calls.
+func (m *Map) Range(f func(key, value any) bool) {
+	// We need to be able to iterate over all of the keys that were already
+	// present at the start of the call to Range.
+	// If read.amended is false, then read.m satisfies that property without
+	// requiring us to hold m.mu for a long time.
+	read := m.loadReadOnly()
+	if read.amended {
+		// m.dirty contains keys not in read.m. Fortunately, Range is already O(N)
+		// (assuming the caller does not break out early), so a call to Range
+		// amortizes an entire copy of the map: we can promote the dirty copy
+		// immediately!
+		m.mu.Lock()
+		read = m.loadReadOnly()
+		if read.amended {
+			read = readOnly{m: m.dirty}
+			m.read.Store(&read)
+			m.dirty = nil
+			m.misses = 0
+		}
+		m.mu.Unlock()
+	}
+
+	for k, e := range read.m {
+		v, ok := e.load()
+		if !ok {
+			continue
+		}
+		if !f(k, v) {
+			break
+		}
+	}
+}
+
+func (m *Map) missLocked() {
+	m.misses++
+	if m.misses < len(m.dirty) {
+		return
+	}
+	m.read.Store(&readOnly{m: m.dirty})
+	m.dirty = nil
+	m.misses = 0
+}
+
+func (m *Map) dirtyLocked() {
+	if m.dirty != nil {
+		return
+	}
+
+	read := m.loadReadOnly()
+	m.dirty = make(map[any]*entry, len(read.m))
+	for k, e := range read.m {
+		if !e.tryExpungeLocked() {
+			m.dirty[k] = e
+		}
+	}
+}
+
+func (e *entry) tryExpungeLocked() (isExpunged bool) {
+	p := e.p.Load()
+	for p == nil {
+		if e.p.CompareAndSwap(nil, expunged) {
+			return true
+		}
+		p = e.p.Load()
+	}
+	return p == expunged
+}
diff --git a/internal/lib/sync/sync.go b/internal/lib/sync/sync.go
index 69075e0c6..c2c88ce70 100644
--- a/internal/lib/sync/sync.go
+++ b/internal/lib/sync/sync.go
@@ -25,10 +25,6 @@ import (
 	"github.com/goplus/llgo/c/pthread/sync"
 )
 
-const (
-	LLGoPackage = "link"
-)
-
 // -----------------------------------------------------------------------------
 
 type Mutex sync.Mutex