diff --git a/c/c.go b/c/c.go
index e8faab82..a38958ed 100644
--- a/c/c.go
+++ b/c/c.go
@@ -46,7 +46,7 @@ type integer interface {
 func Str(string) *Char
 
 // llgo:link Advance llgo.advance
-func Advance[PtrT any](ptr PtrT, offset int) PtrT { return ptr }
+func Advance[PtrT any, I integer](ptr PtrT, offset I) PtrT { return ptr }
 
 // llgo:link Index llgo.index
 func Index[T any, I integer](ptr *T, offset I) T { return *ptr }
diff --git a/internal/runtime/alg.go b/internal/runtime/alg.go
new file mode 100644
index 00000000..52f9e067
--- /dev/null
+++ b/internal/runtime/alg.go
@@ -0,0 +1,368 @@
+// Copyright 2014 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 runtime
+
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/internal/abi"
+	"github.com/goplus/llgo/internal/runtime/c"
+)
+
+const (
+	c0 = uintptr((8-goarchPtrSize)/4*2860486313 + (goarchPtrSize-4)/4*33054211828000289)
+	c1 = uintptr((8-goarchPtrSize)/4*3267000013 + (goarchPtrSize-4)/4*23344194077549503)
+)
+
+/*
+func memhash0(p unsafe.Pointer, h uintptr) uintptr {
+	return h
+}
+
+func memhash8(p unsafe.Pointer, h uintptr) uintptr {
+	return memhash(p, h, 1)
+}
+
+func memhash16(p unsafe.Pointer, h uintptr) uintptr {
+	return memhash(p, h, 2)
+}
+
+func memhash128(p unsafe.Pointer, h uintptr) uintptr {
+	return memhash(p, h, 16)
+}
+
+/*
+//go:nosplit
+func memhash_varlen(p unsafe.Pointer, h uintptr) uintptr {
+	ptr := getclosureptr()
+	size := *(*uintptr)(unsafe.Pointer(ptr + unsafe.Sizeof(h)))
+	return memhash(p, h, size)
+}
+*/
+
+func memhash(p unsafe.Pointer, h, s uintptr) uintptr {
+	h ^= c0
+	for s > 0 {
+		s--
+		h = h*c1 + uintptr(*(*uint8)(c.Advance(p, s)))
+	}
+	return h
+}
+
+func memhash32(p unsafe.Pointer, h uintptr) uintptr {
+	return (h^c0)*c1 + uintptr(*(*uint32)(p))
+}
+
+func memhash64(p unsafe.Pointer, h uintptr) uintptr {
+	return (h^c0)*c1 + uintptr(*(*uint64)(p))
+}
+
+func strhash(p unsafe.Pointer, h uintptr) uintptr {
+	x := (*String)(p)
+	return memhash(x.data, h, uintptr(x.len))
+}
+
+// NOTE: Because NaN != NaN, a map can contain any
+// number of (mostly useless) entries keyed with NaNs.
+// To avoid long hash chains, we assign a random number
+// as the hash value for a NaN.
+
+func f32hash(p unsafe.Pointer, h uintptr) uintptr {
+	f := *(*float32)(p)
+	switch {
+	case f == 0:
+		return c1 * (c0 ^ h) // +0, -0
+	case f != f:
+		return c1 * (c0 ^ h ^ uintptr(fastrand())) // any kind of NaN
+	default:
+		return memhash(p, h, 4)
+	}
+}
+
+func f64hash(p unsafe.Pointer, h uintptr) uintptr {
+	f := *(*float64)(p)
+	switch {
+	case f == 0:
+		return c1 * (c0 ^ h) // +0, -0
+	case f != f:
+		return c1 * (c0 ^ h ^ uintptr(fastrand())) // any kind of NaN
+	default:
+		return memhash(p, h, 8)
+	}
+}
+
+func c64hash(p unsafe.Pointer, h uintptr) uintptr {
+	x := (*[2]float32)(p)
+	return f32hash(unsafe.Pointer(&x[1]), f32hash(unsafe.Pointer(&x[0]), h))
+}
+
+func c128hash(p unsafe.Pointer, h uintptr) uintptr {
+	x := (*[2]float64)(p)
+	return f64hash(unsafe.Pointer(&x[1]), f64hash(unsafe.Pointer(&x[0]), h))
+}
+
+func interhash(p unsafe.Pointer, h uintptr) uintptr {
+	a := (*iface)(p)
+	tab := a.tab
+	if tab == nil {
+		return h
+	}
+	t := tab._type
+	if t.Equal == nil {
+		// Check hashability here. We could do this check inside
+		// typehash, but we want to report the topmost type in
+		// the error text (e.g. in a struct with a field of slice type
+		// we want to report the struct, not the slice).
+		panic(errorString("hash of unhashable type " + t.Name()))
+	}
+	if isDirectIface(t) {
+		return c1 * typehash(t, unsafe.Pointer(&a.data), h^c0)
+	} else {
+		return c1 * typehash(t, a.data, h^c0)
+	}
+}
+
+func nilinterhash(p unsafe.Pointer, h uintptr) uintptr {
+	a := (*eface)(p)
+	t := a._type
+	if t == nil {
+		return h
+	}
+	if t.Equal == nil {
+		// See comment in interhash above.
+		panic(errorString("hash of unhashable type " + t.Name()))
+	}
+	if isDirectIface(t) {
+		return c1 * typehash(t, unsafe.Pointer(&a.data), h^c0)
+	} else {
+		return c1 * typehash(t, a.data, h^c0)
+	}
+}
+
+// typehash computes the hash of the object of type t at address p.
+// h is the seed.
+// This function is seldom used. Most maps use for hashing either
+// fixed functions (e.g. f32hash) or compiler-generated functions
+// (e.g. for a type like struct { x, y string }). This implementation
+// is slower but more general and is used for hashing interface types
+// (called from interhash or nilinterhash, above) or for hashing in
+// maps generated by reflect.MapOf (reflect_typehash, below).
+// Note: this function must match the compiler generated
+// functions exactly. See issue 37716.
+func typehash(t *_type, p unsafe.Pointer, h uintptr) uintptr {
+	if t.TFlag&abi.TFlagRegularMemory != 0 {
+		// Handle ptr sizes specially, see issue 37086.
+		switch t.Size_ {
+		case 4:
+			return memhash32(p, h)
+		case 8:
+			return memhash64(p, h)
+		default:
+			return memhash(p, h, t.Size_)
+		}
+	}
+	switch t.Kind() {
+	case abi.Float32:
+		return f32hash(p, h)
+	case abi.Float64:
+		return f64hash(p, h)
+	case abi.Complex64:
+		return c64hash(p, h)
+	case abi.Complex128:
+		return c128hash(p, h)
+	case abi.String:
+		return strhash(p, h)
+	case abi.Interface:
+		i := (*interfacetype)(unsafe.Pointer(t))
+		if len(i.Methods) == 0 {
+			return nilinterhash(p, h)
+		}
+		return interhash(p, h)
+	case abi.Array:
+		a := (*abi.ArrayType)(unsafe.Pointer(t))
+		for i := uintptr(0); i < a.Len; i++ {
+			h = typehash(a.Elem, add(p, i*a.Elem.Size_), h)
+		}
+		return h
+	case abi.Struct:
+		s := (*abi.StructType)(unsafe.Pointer(t))
+		for _, f := range s.Fields {
+			/* TODO(xsw): skip blank field
+			if f.Name.IsBlank() {
+				continue
+			}
+			*/
+			h = typehash(f.Typ, add(p, f.Offset), h)
+		}
+		return h
+	default:
+		// Should never happen, as typehash should only be called
+		// with comparable types.
+		panic(errorString("hash of unhashable type " + t.Name()))
+	}
+}
+
+/*
+//go:linkname reflect_typehash reflect.typehash
+func reflect_typehash(t *_type, p unsafe.Pointer, h uintptr) uintptr {
+	return typehash(t, p, h)
+}
+
+func memequal0(p, q unsafe.Pointer) bool {
+	return true
+}
+func memequal8(p, q unsafe.Pointer) bool {
+	return *(*int8)(p) == *(*int8)(q)
+}
+func memequal16(p, q unsafe.Pointer) bool {
+	return *(*int16)(p) == *(*int16)(q)
+}
+func memequal32(p, q unsafe.Pointer) bool {
+	return *(*int32)(p) == *(*int32)(q)
+}
+func memequal64(p, q unsafe.Pointer) bool {
+	return *(*int64)(p) == *(*int64)(q)
+}
+func memequal128(p, q unsafe.Pointer) bool {
+	return *(*[2]int64)(p) == *(*[2]int64)(q)
+}
+func f32equal(p, q unsafe.Pointer) bool {
+	return *(*float32)(p) == *(*float32)(q)
+}
+func f64equal(p, q unsafe.Pointer) bool {
+	return *(*float64)(p) == *(*float64)(q)
+}
+func c64equal(p, q unsafe.Pointer) bool {
+	return *(*complex64)(p) == *(*complex64)(q)
+}
+func c128equal(p, q unsafe.Pointer) bool {
+	return *(*complex128)(p) == *(*complex128)(q)
+}
+func strequal(p, q unsafe.Pointer) bool {
+	return *(*string)(p) == *(*string)(q)
+}
+func interequal(p, q unsafe.Pointer) bool {
+	x := *(*iface)(p)
+	y := *(*iface)(q)
+	return x.tab == y.tab && ifaceeq(x.tab, x.data, y.data)
+}
+func nilinterequal(p, q unsafe.Pointer) bool {
+	x := *(*eface)(p)
+	y := *(*eface)(q)
+	return x._type == y._type && efaceeq(x._type, x.data, y.data)
+}
+func efaceeq(t *_type, x, y unsafe.Pointer) bool {
+	if t == nil {
+		return true
+	}
+	eq := t.Equal
+	if eq == nil {
+		panic(errorString("comparing uncomparable type " + t.Name()))
+	}
+	if isDirectIface(t) {
+		// Direct interface types are ptr, chan, map, func, and single-element structs/arrays thereof.
+		// Maps and funcs are not comparable, so they can't reach here.
+		// Ptrs, chans, and single-element items can be compared directly using ==.
+		return x == y
+	}
+	return eq(x, y)
+}
+func ifaceeq(tab *itab, x, y unsafe.Pointer) bool {
+	if tab == nil {
+		return true
+	}
+	t := tab._type
+	eq := t.Equal
+	if eq == nil {
+		panic(errorString("comparing uncomparable type " + t.Name()))
+	}
+	if isDirectIface(t) {
+		// See comment in efaceeq.
+		return x == y
+	}
+	return eq(x, y)
+}
+
+// Testing adapters for hash quality tests (see hash_test.go)
+func stringHash(s string, seed uintptr) uintptr {
+	return strhash(unsafe.Pointer(&s), seed)
+}
+
+func bytesHash(b []byte, seed uintptr) uintptr {
+	s := (*slice)(unsafe.Pointer(&b))
+	return memhash(s.data, seed, uintptr(s.len))
+}
+
+func int32Hash(i uint32, seed uintptr) uintptr {
+	return memhash32(unsafe.Pointer(&i), seed)
+}
+
+func int64Hash(i uint64, seed uintptr) uintptr {
+	return memhash64(unsafe.Pointer(&i), seed)
+}
+
+func efaceHash(i any, seed uintptr) uintptr {
+	return nilinterhash(unsafe.Pointer(&i), seed)
+}
+
+func ifaceHash(i interface {
+	F()
+}, seed uintptr) uintptr {
+	return interhash(unsafe.Pointer(&i), seed)
+}
+
+/*
+const hashRandomBytes = goarch.PtrSize / 4 * 64
+
+// used in asm_{386,amd64,arm64}.s to seed the hash function
+var aeskeysched [hashRandomBytes]byte
+
+// used in hash{32,64}.go to seed the hash function
+var hashkey [4]uintptr
+
+func alginit() {
+	// Install AES hash algorithms if the instructions needed are present.
+	if (GOARCH == "386" || GOARCH == "amd64") &&
+		cpu.X86.HasAES && // AESENC
+		cpu.X86.HasSSSE3 && // PSHUFB
+		cpu.X86.HasSSE41 { // PINSR{D,Q}
+		initAlgAES()
+		return
+	}
+	if GOARCH == "arm64" && cpu.ARM64.HasAES {
+		initAlgAES()
+		return
+	}
+	getRandomData((*[len(hashkey) * goarch.PtrSize]byte)(unsafe.Pointer(&hashkey))[:])
+	hashkey[0] |= 1 // make sure these numbers are odd
+	hashkey[1] |= 1
+	hashkey[2] |= 1
+	hashkey[3] |= 1
+}
+
+func initAlgAES() {
+	useAeshash = true
+	// Initialize with random data so hash collisions will be hard to engineer.
+	getRandomData(aeskeysched[:])
+}
+
+// Note: These routines perform the read with a native endianness.
+func readUnaligned32(p unsafe.Pointer) uint32 {
+	q := (*[4]byte)(p)
+	if goarch.BigEndian {
+		return uint32(q[3]) | uint32(q[2])<<8 | uint32(q[1])<<16 | uint32(q[0])<<24
+	}
+	return uint32(q[0]) | uint32(q[1])<<8 | uint32(q[2])<<16 | uint32(q[3])<<24
+}
+
+func readUnaligned64(p unsafe.Pointer) uint64 {
+	q := (*[8]byte)(p)
+	if goarch.BigEndian {
+		return uint64(q[7]) | uint64(q[6])<<8 | uint64(q[5])<<16 | uint64(q[4])<<24 |
+			uint64(q[3])<<32 | uint64(q[2])<<40 | uint64(q[1])<<48 | uint64(q[0])<<56
+	}
+	return uint64(q[0]) | uint64(q[1])<<8 | uint64(q[2])<<16 | uint64(q[3])<<24 | uint64(q[4])<<32 | uint64(q[5])<<40 | uint64(q[6])<<48 | uint64(q[7])<<56
+}
+*/
diff --git a/internal/runtime/c/c.go b/internal/runtime/c/c.go
index cea55d8b..91a6fc1e 100644
--- a/internal/runtime/c/c.go
+++ b/internal/runtime/c/c.go
@@ -30,11 +30,15 @@ type (
 	FilePtr = unsafe.Pointer
 )
 
+type integer interface {
+	~int | ~uint | ~uintptr | ~int32 | ~uint32 | ~int64 | ~uint64
+}
+
 //go:linkname Str llgo.cstr
 func Str(string) *Char
 
 // llgo:link Advance llgo.advance
-func Advance[PtrT any](ptr PtrT, offset int) PtrT { return ptr }
+func Advance[PtrT any, I integer](ptr PtrT, offset I) PtrT { return ptr }
 
 //go:linkname Alloca llgo.alloca
 func Alloca(size uintptr) Pointer
diff --git a/internal/runtime/malloc.go b/internal/runtime/malloc.go
index c23f1bd0..bcfd5216 100644
--- a/internal/runtime/malloc.go
+++ b/internal/runtime/malloc.go
@@ -8,6 +8,10 @@ import (
 	"unsafe"
 )
 
+const (
+	bigAlloc = 1 << (goarchPtrSize*8 - 6)
+)
+
 // implementation of new builtin
 // compiler (both frontend and SSA backend) knows the signature
 // of this function.
diff --git a/internal/runtime/map.go b/internal/runtime/map.go
index ce69bb34..23fad661 100644
--- a/internal/runtime/map.go
+++ b/internal/runtime/map.go
@@ -308,15 +308,14 @@ func makemap_small() *hmap {
 	return h
 }
 
-/*
 // makemap implements Go map creation for make(map[k]v, hint).
 // If the compiler has determined that the map or the first bucket
 // can be created on the stack, h and/or bucket may be non-nil.
 // If h != nil, the map can be created directly in h.
 // If h.buckets != nil, bucket pointed to can be used as the first bucket.
 func makemap(t *maptype, hint int, h *hmap) *hmap {
-	mem, overflow := math.MulUintptr(uintptr(hint), t.Bucket.Size_)
-	if overflow || mem > maxAlloc {
+	mem, overflow := mathMulUintptr(uintptr(hint), t.Bucket.Size_)
+	if overflow || mem > bigAlloc {
 		hint = 0
 	}
 
@@ -348,7 +347,6 @@ func makemap(t *maptype, hint int, h *hmap) *hmap {
 
 	return h
 }
-*/
 
 // makeBucketArray initializes a backing array for map buckets.
 // 1<<b is the minimum number of buckets to allocate.
diff --git a/internal/runtime/stubs.go b/internal/runtime/stubs.go
index 5835c97d..349aecc4 100644
--- a/internal/runtime/stubs.go
+++ b/internal/runtime/stubs.go
@@ -193,8 +193,6 @@ func memequal(a, b unsafe.Pointer, size uintptr) bool
 // output depends on the input.  noescape is inlined and currently
 // compiles down to zero instructions.
 // USE CAREFULLY!
-//
-//go:nosplit
 func noescape(p unsafe.Pointer) unsafe.Pointer {
 	x := uintptr(p)
 	return unsafe.Pointer(x ^ 0)
diff --git a/internal/runtime/type.go b/internal/runtime/type.go
deleted file mode 100644
index 2f8cbf2c..00000000
--- a/internal/runtime/type.go
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright 2009 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.
-
-// Runtime type representation.
-
-package runtime
-
-/*
-import (
-	"github.com/goplus/llgo/internal/abi"
-)
-
-type _type = abi.Type
-
-type maptype = abi.MapType
-
-type arraytype = abi.ArrayType
-
-type chantype = abi.ChanType
-
-type slicetype = abi.SliceType
-
-type functype = abi.FuncType
-
-type ptrtype = abi.PtrType
-
-type name = abi.Name
-
-type structtype = abi.StructType
-*/
diff --git a/internal/runtime/z_face.go b/internal/runtime/z_face.go
index 0e6455ff..6574369f 100644
--- a/internal/runtime/z_face.go
+++ b/internal/runtime/z_face.go
@@ -25,6 +25,11 @@ import (
 
 type _type = abi.Type
 
+// isDirectIface reports whether t is stored directly in an interface value.
+func isDirectIface(t *_type) bool {
+	return t.Kind_&abi.KindDirectIface != 0
+}
+
 type eface struct {
 	_type *_type
 	data  unsafe.Pointer
diff --git a/internal/runtime/z_map.go b/internal/runtime/z_map.go
index 0a1b3168..500fa1f1 100644
--- a/internal/runtime/z_map.go
+++ b/internal/runtime/z_map.go
@@ -24,13 +24,105 @@ import (
 
 // Map represents a Go map.
 type Map = hmap
+type MapType = abi.MapType
 
 // MakeSmallMap creates a new small map.
 func MakeSmallMap() *Map {
 	return makemap_small()
 }
 
-// Mapassign finds a key in map m and returns the elem address to assign.
-func Mapassign(t *abi.MapType, m *Map, key unsafe.Pointer) unsafe.Pointer {
+// MakeMap creates a new map.
+func MakeMap(t *MapType, hint int, at *Map) *Map {
+	return makemap(t, hint, at)
+}
+
+// MapAssign finds a key in map m and returns the elem address to assign.
+func MapAssign(t *MapType, m *Map, key unsafe.Pointer) unsafe.Pointer {
 	return mapassign(t, m, key)
 }
+
+func isReflexive(key *Type) bool {
+	return true // TODO(xsw): false for float/complex type
+}
+
+func hashOf(t *Type) func(key unsafe.Pointer, hash0 uintptr) uintptr {
+	if t.TFlag&abi.TFlagRegularMemory != 0 {
+		switch t.Size_ {
+		case 4:
+			return memhash32
+		case 8:
+			return memhash64
+		}
+		return func(key unsafe.Pointer, hash0 uintptr) uintptr {
+			return memhash(key, hash0, t.Size_)
+		}
+	}
+	switch t.Kind() {
+	case abi.Float32:
+		return f32hash
+	case abi.Float64:
+		return f64hash
+	case abi.Complex64:
+		return c64hash
+	case abi.Complex128:
+		return c128hash
+	case abi.String:
+		return strhash
+	case abi.Interface:
+		i := (*interfacetype)(unsafe.Pointer(t))
+		if len(i.Methods) == 0 {
+			return nilinterhash
+		}
+		return interhash
+	}
+	return func(key unsafe.Pointer, hash0 uintptr) uintptr {
+		return typehash(t, key, hash0)
+	}
+}
+
+// MapOf creates a new map type.
+func MapOf(key, elem *Type) *MapType {
+	var flags uint32
+
+	keySlot, elemSlot := key, elem
+	ptrTy := Basic(abi.UnsafePointer)
+	if keySlot.Size_ > 128 {
+		keySlot = ptrTy
+		flags |= 1
+	}
+	if elemSlot.Size_ > 128 {
+		elemSlot = ptrTy
+		flags |= 2
+	}
+	if isReflexive(key) {
+		flags |= 4
+	}
+
+	tophashTy := ArrayOf(bucketCnt, Basic(abi.Uint8))
+	keysTy := ArrayOf(bucketCnt, keySlot)
+	elemsTy := ArrayOf(bucketCnt, elemSlot)
+
+	tophash := StructField("tophash", tophashTy, 0, "", false)
+	keys := StructField("keys", keysTy, tophashTy.Size_, "", false)
+	elems := StructField("elems", elemsTy, keys.Offset+keysTy.Size_, "", false)
+	overflow := StructField("overflow", ptrTy, elems.Offset+elemsTy.Size_, "", false)
+
+	bucket := Struct("", overflow.Offset+ptrTy.Size_, tophash, keys, elems, overflow)
+
+	ret := &abi.MapType{
+		Type: abi.Type{
+			Size_: unsafe.Sizeof(uintptr(0)),
+			Hash:  uint32(abi.Map),
+			Kind_: uint8(abi.Map),
+		},
+		Key:        key,
+		Elem:       elem,
+		Bucket:     bucket,
+		Hasher:     hashOf(key),
+		KeySize:    uint8(keySlot.Size_),  // size of key slot
+		ValueSize:  uint8(elemSlot.Size_), // size of elem slot
+		BucketSize: uint16(bucket.Size_),  // size of bucket
+		Flags:      flags,
+	}
+	return ret
+}
diff --git a/internal/runtime/z_slice.go b/internal/runtime/z_slice.go
index f4711e47..61c80381 100644
--- a/internal/runtime/z_slice.go
+++ b/internal/runtime/z_slice.go
@@ -25,7 +25,9 @@ import (
 // -----------------------------------------------------------------------------
 
 // Slice is the runtime representation of a slice.
-type Slice struct {
+type Slice = slice
+
+type slice struct {
 	data unsafe.Pointer
 	len  int
 	cap  int
diff --git a/py/README.md b/py/README.md
index 16d3bbc3..32479857 100644
--- a/py/README.md
+++ b/py/README.md
@@ -19,10 +19,10 @@ To run the demos in directory `_demo`, you need to set the `LLGO_LIB_PYTHON` env
 export LLGO_LIB_PYTHON=/foo/bar/python3.12
 ```
 
-For example, `/opt/homebrew/Frameworks/Python.framework/Versions/3.12/libpython3.12.dylib` is a typical python lib location under macOS. So we should set it like this:
+For example, `/opt/homebrew/Frameworks/Python.framework/Versions/3.12/lib/libpython3.12.dylib` is a typical python lib location under macOS. So we should set it like this:
 
 ```sh
-export LLGO_LIB_PYTHON=/opt/homebrew/Frameworks/Python.framework/Versions/3.12/python3.12
+export LLGO_LIB_PYTHON=/opt/homebrew/Frameworks/Python.framework/Versions/3.12/lib/python3.12
 ```
 
 Then you can run the demos in directory `_demo`:
diff --git a/ssa/datastruct.go b/ssa/datastruct.go
index 819e6d21..9981ca8f 100644
--- a/ssa/datastruct.go
+++ b/ssa/datastruct.go
@@ -360,8 +360,13 @@ func (b Builder) MapUpdate(m, k, v Expr) {
 	if debugInstr {
 		log.Printf("MapUpdate %v[%v] = %v\n", m.impl, k.impl, v.impl)
 	}
-	// TODO(xsw)
-	// panic("todo")
+	t := m.Type
+	if t.kind != vkMap {
+		panic("TODO: not a map")
+	}
+	tabi := b.abiType(t.raw.Type)
+	ptr := b.InlineCall(b.Pkg.rtFunc("MapAssign"), tabi, m, k)
+	b.Store(ptr, v) // TODO(xsw): indirect store
 }
 
 // -----------------------------------------------------------------------------