diff --git a/cl/compile_test.go b/cl/compile_test.go
index 8c4f9706..ad15268c 100644
--- a/cl/compile_test.go
+++ b/cl/compile_test.go
@@ -19,7 +19,6 @@ package cl_test
 import (
 	"os"
 	"path/filepath"
-	"runtime"
 	"testing"
 
 	"github.com/goplus/llgo/cl"
@@ -71,13 +70,11 @@ func TestPython(t *testing.T) {
 	cltest.Pkg(t, ssa.PkgPython, "../py/llgo_autogen.ll")
 }
 
-func TestGoLibMath(t *testing.T) {
-	if runtime.GOOS == "darwin" { // TODO(xsw): support linux/windows
-		root, _ := filepath.Abs("..")
-		os.Setenv("LLGOROOT", root)
-		conf := build.NewDefaultConf(build.ModeInstall)
-		build.Do([]string{"math"}, conf)
-	}
+func TestGoPkgMath(t *testing.T) {
+	root, _ := filepath.Abs("..")
+	os.Setenv("LLGOROOT", root)
+	conf := build.NewDefaultConf(build.ModeInstall)
+	build.Do([]string{"math"}, conf)
 }
 
 func TestVar(t *testing.T) {
diff --git a/internal/packages/load.go b/internal/packages/load.go
index 92ba808a..8f8640eb 100644
--- a/internal/packages/load.go
+++ b/internal/packages/load.go
@@ -99,13 +99,33 @@ type loader struct {
 	requestedMode LoadMode
 }
 
-type Deduper struct {
+type cachedPackage struct {
+	Types     *types.Package
+	TypesInfo *types.Info
+	Syntax    []*ast.File
 }
 
-func NewDeduper() *Deduper {
+type aDeduper struct {
+	cache sync.Map
+}
+
+type Deduper = *aDeduper
+
+func NewDeduper() Deduper {
+	return &aDeduper{}
+}
+
+func (p Deduper) check(pkgPath string) *cachedPackage {
+	if v, ok := p.cache.Load(pkgPath); ok {
+		return v.(*cachedPackage)
+	}
 	return nil
 }
 
+func (p Deduper) set(pkgPath string, cp *cachedPackage) {
+	p.cache.Store(pkgPath, cp)
+}
+
 //go:linkname defaultDriver golang.org/x/tools/go/packages.defaultDriver
 func defaultDriver(cfg *Config, patterns ...string) (*packages.DriverResponse, bool, error)
 
@@ -130,7 +150,7 @@ type importerFunc func(path string) (*types.Package, error)
 
 func (f importerFunc) Import(path string) (*types.Package, error) { return f(path) }
 
-func loadPackageEx(dedup *Deduper, ld *loader, lpkg *loaderPackage) {
+func loadPackageEx(dedup Deduper, ld *loader, lpkg *loaderPackage) {
 	if lpkg.PkgPath == "unsafe" {
 		// Fill in the blanks to avoid surprises.
 		lpkg.Types = types.Unsafe
@@ -141,6 +161,26 @@ func loadPackageEx(dedup *Deduper, ld *loader, lpkg *loaderPackage) {
 		return
 	}
 
+	if dedup != nil {
+		if cp := dedup.check(lpkg.PkgPath); cp != nil {
+			lpkg.Types = cp.Types
+			lpkg.Fset = ld.Fset
+			lpkg.TypesInfo = cp.TypesInfo
+			lpkg.Syntax = cp.Syntax
+			lpkg.TypesSizes = ld.sizes
+			return
+		}
+		defer func() {
+			if !lpkg.IllTyped && lpkg.needtypes && lpkg.needsrc {
+				dedup.set(lpkg.PkgPath, &cachedPackage{
+					Types:     lpkg.Types,
+					TypesInfo: lpkg.TypesInfo,
+					Syntax:    lpkg.Syntax,
+				})
+			}
+		}()
+	}
+
 	// Call NewPackage directly with explicit name.
 	// This avoids skew between golist and go/types when the files'
 	// package declarations are inconsistent.
@@ -404,7 +444,7 @@ func loadPackageEx(dedup *Deduper, ld *loader, lpkg *loaderPackage) {
 	lpkg.IllTyped = illTyped
 }
 
-func loadRecursiveEx(dedup *Deduper, ld *loader, lpkg *loaderPackage) {
+func loadRecursiveEx(dedup Deduper, ld *loader, lpkg *loaderPackage) {
 	lpkg.loadOnce.Do(func() {
 		// Load the direct dependencies, in parallel.
 		var wg sync.WaitGroup
@@ -421,7 +461,7 @@ func loadRecursiveEx(dedup *Deduper, ld *loader, lpkg *loaderPackage) {
 	})
 }
 
-func refineEx(dedup *Deduper, ld *loader, response *packages.DriverResponse) ([]*Package, error) {
+func refineEx(dedup Deduper, ld *loader, response *packages.DriverResponse) ([]*Package, error) {
 	roots := response.Roots
 	rootMap := make(map[string]int, len(roots))
 	for i, root := range roots {
@@ -641,7 +681,7 @@ func refineEx(dedup *Deduper, ld *loader, response *packages.DriverResponse) ([]
 // return an error. Clients may need to handle such errors before
 // proceeding with further analysis. The PrintErrors function is
 // provided for convenient display of all errors.
-func LoadEx(dedup *Deduper, sizes func(types.Sizes) types.Sizes, cfg *Config, patterns ...string) ([]*Package, error) {
+func LoadEx(dedup Deduper, sizes func(types.Sizes) types.Sizes, cfg *Config, patterns ...string) ([]*Package, error) {
 	ld := newLoader(cfg)
 	response, external, err := defaultDriver(&ld.Config, patterns...)
 	if err != nil {